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• Can't install .NET framework 4.0 on Windows XP professional version 2002 SP3 (OS bug?)

  - by that guy

  .NET framework 4.0 install fails on Windows XP professional version 2002 SP3: I tried to run setup using "run as..." to make sure the admin rights are used ("protect my computer..." tick was deselected of course). I tried everything: installing using online/offline setup, windows update. install goes a little and then "rolls back" and says: Installation did not succeed .NET Framework 4 has not been installed because: Fatal error during installation. for more information about this problem, see the log file. the full log: http://pastebay.net/1433771 Any ideas? EDIT1: I have found this in the log: "BlockIf: You must install the 32-bit Windows Imaging Component (WIC) before you run Setup. Please visit the Microsoft Download Center to install WIC, and then rerun Setup...." So I found it, and launched "wic_x86_enu.exe" - but it said: WIC Setup error Newer version of update is already on the system. I have already installed: .NET framewrok 2.0 SP2 .NET framewrok 3.0 SP2 .NET framewrok 3.5 SP1 but I need 4.0 . EDIT2: another attempt and it's log. (this time better copy of log file): http://pastebin.com/gmGfbM9a (copy to notepad and save as .htm and open with internet browser). I have tried all the solutions I could find - and nothing helped. I have found something weird: when I formatted the hard drive and installed windows xp again - the .NET framework 4.0 installed ok, but when I plugged my 100Mbit internet cable - the operating system kind off "locked itself" and the bug returned - I could no longer install .NET framework 4.0 again. There was no reason for that to happen, for example I have windows server 2003 in local network, but I don't have active directory enabled on it or anything like that - the server just has some folders shared and thats all (all server's "features" are default). I had the second pc with the same problem - with XP on it too. This seems like the bug of Operating System to me. I couldn't find what was causing the problem. After many days I gave up: backuped everything, formatted HDD and installed Windows 7 professional 64bit. .NET framework 4.0 installed with no problem on it.

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• I Didn&rsquo;t Get You Anything&hellip;

  - by Bob Rhubart

  Nearly every day this blog features a  list posts and articles written by members of the OTN architect community. But with Christmas just days away, I thought a break in that routine was in order. After all, if the holidays aren’t excuse enough for an off-topic post, then the terrorists have won. Rather than buy gifts for everyone -- which, given the readership of this blog and my budget could amount to a cash outlay of upwards of $15.00 – I thought I’d share a bit of holiday humor. I wrote the following essay back in the mid-90s, for a “print” publication that used “paper” as a content delivery system.  That was then. I’m older now, my kids are older, but my feelings toward the holidays haven’t changed… It’s New, It’s Improved, It’s Christmas! The holidays are a time of rituals. Some of these, like the shopping, the music, the decorations, and the food, are comforting in their predictability. Other rituals, like the shopping, the  music, the decorations, and the food, can leave you curled into the fetal position in some dark corner, whimpering. How you react to these various rituals depends a lot on your general disposition and credit card balance. I, for one, love Christmas. But there is one Christmas ritual that really tangles my tinsel: the seasonal editorializing about how our modern celebration of the holidays pales in comparison to that of Christmas past. It's not that the old notions of how to celebrate the holidays aren't all cozy and romantic--you can't watch marathon broadcasts of "It's A Wonderful White Christmas Carol On Thirty-Fourth Street Story" without a nostalgic teardrop or two falling onto your plate of Christmas nachos. It's just that the loudest cheerleaders for "old-fashioned" holiday celebrations overlook the fact that way-back-when those people didn't have the option of doing it any other way. Dashing through the snow in a one-horse open sleigh? No thanks. When Christmas morning rolls around, I'm going to be mighty grateful that the family is going to hop into a nice warm Toyota for the ride over to grandma's place. I figure a horse-drawn sleigh is big fun for maybe fifteen minutes. After that you’re going to want Old Dobbin to haul ass back to someplace warm where the egg nog is spiked and the family can gather in the flickering glow of a giant TV and contemplate the true meaning of football. Chestnuts roasting on an open fire? Sorry, no fireplace. We've got a furnace for heat, and stuffing nuts in there voids the warranty. Any of the roasting we do these days is in the microwave, and I'm pretty sure that if you put chestnuts in the microwave they would become little yuletide hand grenades. Although, if you've got a snoot full of Yule grog, watching chestnuts explode in your microwave might be a real holiday hoot. Some people may see microwave ovens as a symptom of creeping non-traditional holiday-ism. But I'll bet you that if there were microwave ovens around in Charles Dickens' day, the Cratchits wouldn't have had to entertain an uncharacteristically giddy Scrooge for six or seven hours while the goose cooked. Holiday entertaining is, in fact, the one area that even the most severe critic of modern practices would have to admit has not changed since Tim was Tiny. A good holiday celebration, then as now, involves lots of food, free-flowing drink, and a gathering of friends and family, some of whom you are about as happy to see as a subpoena. Just as the Cratchit's Christmas was spent with a man who, for all they knew, had suffered some kind of head trauma, so the modern holiday gathering includes relatives or acquaintances who, because they watch too many talk shows, and/or have poor personal hygiene, and/or fail to maintain scheduled medication, you would normally avoid like a plate of frosted botulism. But in the season of good will towards men, you smile warmly at the mystery uncle wandering around half-crocked with a clump of mistletoe dangling from the bill of his N.R.A. cap. Dickens' story wouldn't have become the holiday classic it has if, having spotted on their doorstep an insanely grinning, raw poultry-bearing, fresh-off-a-rough-night Scrooge, the Cratchits had pulled their shades and pretended not to be home. Which is probably what I would have done. Instead, knowing full well his reputation as a career grouch, they welcomed him into their home, and we have a touching story that teaches a valuable lesson about how the Christmas spirit can get the boss to pump up the payroll. Despite what the critics might say, our modern Christmas isn't all that different from those of long ago. Sure, the technology has changed, but that just means a bigger, brighter, louder Christmas, with lasers and holograms and stuff. It's our modern celebration of a season that even the least spiritual among us recognizes as a time of hope that the nutcases of the world will wake up and realize that peace on earth is a win/win proposition for everybody. If Christmas has changed, it's for the better. We should continue making Christmas bigger and louder and shinier until everybody gets it.  *** Happy Holidays, everyone!   del.icio.us Tags: holiday,humor Technorati Tags: holiday,humor

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• SQL Saturday #44 Huntington Beach Recap

  What a great day. It was long and tiring, but rewarding in so many ways. On Sunday morning, I was driving home and I decided to take the Pacific Coast Highway from Huntington Beach.  It was a great chance to exhale and just enjoy the sun and smells of the beach (I really love SoCal sometimes). And for future reference for all you speakers, the beach and ocean are only 5 minutes from the SQL Saturday location.  I just could help noticing also the shocking number of high priced cars on the road (4 Bentleys, 3 Ferraris, 1 Aston Martins, 3 Maserati, 1 Rolls Royce, and 2 Lamborghinis).  It made me think about this: Price of all those cars: $ 150,000+.  Impacting the ability of people to learn: Priceless.  We have positively impacted the education, knowledge, capabilities of not only our attendees, but also all of their companies and people they might help as well.  That is just staggering and something to be immensely proud of. To all of my fellow community leaders, I salute you. So lets talk about the event Overall We had over 220 people register for the event and had 180+ people attend the event. I was shooting for the magical 200 number, but I guess it just gives us more motivation to make it even bigger and better next time. We had a few snags along the way, but what event doesnt, but I think everything turned out great. I did not hear any negative comments and heard lots of positive comments along with people asking when the next one is going to be (More on that later). Location- Golden West College We could not have asked for a better partner for the event. Herb Cohen from Golden West College was the wizard behind the curtains. From the beginning, he was our advocate to the GWC Board and was instrumental in getting our event approved. The day off, Herb was a HUGE help getting any and all logistics that we needed taken care of. In the craziness of the early morning registration crush it was a big help knowing that he and Bret Stateham (Blog | Twitter) were taking care of testing projectors in all the rooms. Anything we needed he was there and was even proactive in getting some things that I had not even thought of (i.e. a dumpster for all of our garbage). I cannot thank Herb enough along with other members of the GWC staff including Minnie Higgins of the Career and Technical Education Division office, Jack Taylor, public safety, and Ron Pryor, Tech Services Support. And last, but not least, the Wireless on campus was absolutely FANTASTIC! Some lessons learned Unless you are a glutton for punishment, as I no doubt am, you most certainly want to give yourself more than six weeks to plan the event. I am lucky that I have a very understanding wife and had a wonderful set of co-coordinators helping me out. A big thanks goes out to Phil, Marlon (Blog | Twitter), Nitin (Twitter), Thomas (Blog | Twitter), Bret (Blog | Twitter), Ben, and Laurie. Thankfully, the sponsor and speaker community was hugely supportive and we were able to fill out the entire event with speakers and sponsors. I have to say that there is not a lot that I would change after this years event. There are obviously going to be some things that we can do better or differently next time, but overall I think it was a great event and I was more than happy with the response we received from the community. Sponsors We obviously could not have put together our event without our sponsors. So certainly have to show them some love. Platinum Sponsors Quest Software http://www.quest.com My Space http://www.myspace.com/ Gold Strategy Companion http://www.strategycompanion.com Silver Fusion-IO http://www.fusionio.com Bronze WestClinTech http://westclintech.com Professional Association For SQL Server http://www.sqlpass.org Attunity http://www.attunity.com Sharepoint 360 http://www.sharepoint360.com Some additional Thanks Andy Warren (Blog | Twitter) Always there to answer my question and help out when I had some issues or questions with the website. The amount of work that he and everyone else put into SQL Saturday is very amazing. What a great gift to the community! Einstein Bros. Bagels They were our Breakfast Vendor and arrived perfectly on time with yummy bagels, sweets and most importantly coffee. Luccis Deli (http://www.luccisdeli.com) Luccis was out Lunch Vendor. They were great to work with and the food was excellent. They worked with us to give us a great price. Heard lots of great comments about the lunches. Definitely not your ordinary box lunch. Moving Forward Unfortunately, the work does not end after the event. We have a few things to clear up such as surveys, sponsor stuff, presentations uploaded to the website, expense reimbursement, stuff like that. Hopefully, all that should be cleared up within the next couple weeks. After that as a group we are going to get together and decide what our next steps are. We definitely want to keep some of the momentum that we are building as a SQL Community and channel that into future SQL Saturdays and other types of community events. In the meantime, for additional training be sure to check out your local User Group and PASS. San Diego SQL Server Users Group ( http://www.sdsqlug.org/home/index.cfm ) Orange County SQL Server Users Group ( http://www.sqloc.com/ ) L.A. SQL Server Users Group ( http://www.sql.la/ ) SQL PASS ( http://www.sqlpass.org/ ) 24 Hours of PASS ( http://www.sqlpass.org/24hours/2010/ ) So stay tuned, there will be more events to come in SoCal!!Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• Red Gate does Byte Night 2012

  - by red(at)work

  On the 5th of October 2012, a team of nine plucky Red Gaters braved the howling wind and the driving rain to sleep outside. No tents or mattresses were allowed – all we took for protection were sleeping bags, groundsheets, plastic sacks and Colin’s enormous fishing umbrella (a godsend in umbrella-y disguise). Why would we do such a thing? For Byte Night, an annual tech sector sleepout in support of Action for Children, who tackle the causes as well as the consequences of youth homelessness. Byte Night encourages technology professionals to do for one night a year what thousands of young people have to do every night – sleep rough.  We signed up for Byte Night in the warm, heady midst of the British summer, thinking it couldn’t possibly be all that bad. Even on the night itself – before the rain began to fall, sat in the comfort and warmth of a company canteen, drinking wine and eating chill and preparing to win the pub quiz – we were excited and optimistic about the night that lay ahead of us. All of that changed as soon as we stepped out into one of the worst rainstorms of the year. Brian, the team’s birthday boy, describes it best: Picture the scene: it’s 3 am on a Friday. I’m lying outside, fully clothed in a sleeping bag, wearing a raincoat, trussed up inside a large plastic pocket, on a ground sheet beneath a giant umbrella, wedged so tightly between two of my colleagues that I can’t move my arms. I’m wide awake, staring up at the grey sky beyond the edge of the umbrella; a limp, flickering white glow hints at a moon somewhere behind the drifting clouds. I haven’t slept since we first moved outside at 11 pm. Outside. Did I mention we were outside? I’m hung over. I need the loo. But there is no way on earth that I’m getting out of this sleeping bag. It’s cold. It’s raining. Not just raining, but chucking it down. It’s been doing this non-stop since 10pm. The rain sounds like a hyperactive drummer on the fishing umbrella, and the noise is loud and relentless. Puddles of water are forming all over the groundsheet, and, despite being ensconced inside the plastic pouch, I am wet. The fishing umbrella is protecting me from the worst of the driving rain, but not all of me is under it, and five hours of rain is no match for it. Everything is wet. My left side has become horribly damp. My trainers, which I placed next to my sleeping bag, are now completely soaked through. Mmm. That’ll be fun in the morning. My head is next to Colin’s head on one side, and a multi-pack of McCoy’s cheddar and onion crisps on the other. Don’t ask about the tub of hummus. That’s somewhere down by my ankles, abandoned to the night. Jess, who is lying next to me, rolls over onto her side. A mini waterfall cascades from her rain-pouch onto my face. Bah. I continue to stare into the heavens, willing the dawn to hurry up. Something lands on my face. It’s a mosquito. Great. Midnight, when this still seemed like fun – when we opened some champagne and my colleagues presented me with a caterpillar birthday cake, when everyone was drunk and jolly and full of stoic resolve – feels like a long time ago. Did I mention that today is my birthday? The remains of the caterpillar cake endure the same fate as the hummus, left out in the rain like a metaphor for sadness. It’s getting colder. I can see my breath. Silence has descended on the group, apart from the rustle of plastic. And the rain, obviously. Someone snores, and I envy whoever it is the sweet escape of sleep. I try to wriggle a bit further down inside my sleeping bag, but it doesn’t want to be wriggled into. Only 3 hours till dawn. 180 minutes. I begin to count them off, one at a time.  All nine of us got to go home in the morning, but thousands of children across the UK don’t have that luxury. If you’d like to sponsor the Red Gate Byte Night team, our JustGiving page can be found here.   Chris, before the outside bit actually happened. More photos from Byte Night Cambridge 2012 can be found here.

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• Stand-Up Desk 2012 Update

  - by BuckWoody

  One of the more popular topics here on my technical blog doesn't have to do with technology, per-se - it's about the choice I made to go to a stand-up desk work environment. If you're interested in the history of those, check here: Stand-Up Desk Part One Stand-Up Desk Part Two I have made some changes and I was asked to post those here.Yes, I'm still standing - I think the experiment has worked well, so I'm continuing to work this way. I've become so used to it that I notice when I sit for a long time. If I'm flying, or driving a long way, or have long meetings, I take breaks to stand up and move around. That being said, I don't stand as much as I did. I started out by standing the entire day - which did not end well. As you can read in my second post, I found that sitting down for a few minutes each hour worked out much better. And over time I would say that I now stand about 70-80% of the day, depending on the day. Some days I don't even notice I'm standing, so I don't sit as often. Other days I find that I really tire quickly - so I sit more often. But in both cases, I stand more than I sit. In the first post you can read about how I used a simple coffee-table from Ikea to elevate my desktop to the right height. I then adjusted the height where I stand by using a small plastic square and some carpet. Over time I found this did not work as well as I'd like. The primary reason is that the front of these are at the same depth - so my knees would hit the desk or table when I sat down. Also, the desk was at a certain height, and I had to adjust, rather than the other way around.  Also, I like a lot of surface area on top of a desk - almost more of a table. Routing cables and wiring was a pain, and of course moving it was out of the question.   So I've changed what I use. I found a perfect solution for what I was looking for - industrial wire shelving: I bought one, built only half of it (for the right height I wanted) and arranged the shelves the way I wanted. I then got a 5'x4' piece of wood from Lowes, and mounted it to where the top was balanced, but had an over-hang  I could get my knees under easily.My wife sewed a piece of fake-leather for the top. This arrangement provides the following benefits: Very strong Rolls easily, wheels can lock to prevent rolling Long, wide shelves Wire-frame allows me to route any kind of wiring and other things all over the desk I plugged in my UPS and ran it's longer power-cable to the wall outlet. I then ran the router's LAN connection along that wire, and covered both with a large insulation sleeve. I then plugged in everything to the UPS, and routed all the wiring. I can now roll the desk almost anywhere in the room so that I can record, look out the window, get closer to or farther away from the door and more. I put a few boxes on the shelves as "drawers" and tidied that part up. Even my printer fits on a shelf. Laser-dog not included - some assembly required In the second post you can read about the bar-stool I purchased from Target for the desk. I cheaped-out on this one, and it proved to be a bad choice. Because I had to raise it so high, and was constantly sitting on it and then standing up, the gas-cylinder in it just gave out. So it became a very short stool that I ended up getting rid of. In the end, this one from Ikea proved to be a better choice: And so this arrangement is working out perfectly. I'm finding myself VERY productive this way. I hope these posts help you if you decide to try working at a stand-up desk. Although I was skeptical at first, I've found it to be a very healthy, easy way to code, design and especially present over a web-cam. It's natural to stand to speak when you're presenting, and it feels more energetic than sitting down to talk to others.

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• Google Maps Rollover Problem in a Flex Website

  - by Laxmidi

  Hi, I'm using Google Maps in my Flex site to create a map. I've got polygons overlayed on the map. When the user rolls over a polygon an infowindow opens identifying the area and the fill Alpha of the area is set to 0. On roll-out, the info window is removed and the fill Alpha is returned to the default, 0.2. The polygons display and the InfoWindow is added and removed correctly. The problem is that the change in fill alpha only occurs on the very last polygon in the list. So for example, if I have polygons A, B, C, and D. If I rollover A, then A's alpha should change. But, instead D's alpha changes. No matter which polygon I rollover, the last polygon's alpha changes. It's weird, because the infoWindows behave correctly on rollover. So, if I rollover polygon A, the correct information for InfoWindow A appears. Please see the code below: private function allEncodedPolygons(event:MouseEvent) : void { var myPaneManager:IPaneManager = map.getPaneManager(); var myMapPane:IPane = myPaneManager.createPane(); if (allHoodsToggle.selected) { map.clearOverlays(); mapType.selectedIndex = -1; for each (var neighbNode:XML in detailMapResultData){ outlinePolygon = this.createPoly(neighbNode); map.addOverlay(outlinePolygon)}; allHoodsToggle.removeEventListener(MouseEvent.CLICK, allEncodedPolygons); } else {myPaneManager.clearOverlays(); allHoodsToggle.removeEventListener(MouseEvent.CLICK, allEncodedPolygons); } } The function below creates the polygons and has the rollover function: private var neighbShapes:Polygon; private function createPoly(neighbNode:XML):Polygon { var optionsDefault:PolygonOptions = new PolygonOptions( { strokeStyle: {thickness: 5, color: 0xFFFF00, alpha: 0.4, pixelHinting: true}, fillStyle: { alpha: 0.2 }} ); var neighbCenterLat:Number = neighbNode.latitudeCenter.toString(); var neighbCenterLong:Number = neighbNode.longitudeCenter.toString(); var neighbCenter:LatLng = new LatLng(neighbCenterLat,neighbCenterLong); var optionsHover:PolygonOptions = new PolygonOptions( { fillStyle: { alpha: 0.0 }} ); var encodedData:EncodedPolylineData = new EncodedPolylineData(neighbNode.encoding.toString(), neighbNode.zoomFactor.toString(), neighbNode.level.toString(), neighbNode.numlevels.toString()); var encodedList:Array = [encodedData]; neighbShapes = Polygon.fromEncoded(encodedList, optionsDefault); neighbShapes.addEventListener(MapMouseEvent.CLICK, function(event:MapMouseEvent): void { map.openInfoWindow(event.latLng, new InfoWindowOptions({content: neighbNode.name.toString(), hasCloseButton:false, hasShadow:true})); }); neighbShapes.addEventListener(MapMouseEvent.ROLL_OVER, function(event:MapMouseEvent): void { neighbShapes.setOptions(optionsHover); map.openInfoWindow(neighbCenter, new InfoWindowOptions({content: neighbNode.name.toString(), hasCloseButton:false, hasShadow:false})); }); neighbShapes.addEventListener(MapMouseEvent.ROLL_OUT, function(event:MapMouseEvent): void { neighbShapes.setOptions(optionsDefault); }); return neighbShapes; } Any suggestions as to why the function that changes the alpha is firing on the last polygon only, even though the InfoWindow appears correctly? If anyone has any ideas, I'd love to hear them. Thanks. -Laxmidi

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• quartz: preventing concurrent instances of a job in jobs.xml

  - by Jason S

  This should be really easy. I'm using Quartz running under Apache Tomcat 6.0.18, and I have a jobs.xml file which sets up my scheduled job that runs every minute. What I would like to do, is if the job is still running when the next trigger time rolls around, I don't want to start a new job, so I can let the old instance complete. Is there a way to specify this in jobs.xml (prevent concurrent instances)? If not, is there a way I can share access to an in-memory singleton within my application's Job implementation (is this through the JobExecutionContext?) so I can handle the concurrency myself? (and detect if a previous instance is running) update: After floundering around in the docs, here's a couple of approaches I am considering, but either don't know how to get them to work, or there are problems. Use StatefulJob. This prevents concurrent access... but I'm not sure what other side-effects would occur if I use it, also I want to avoid the following situation: Suppose trigger times would be every minute, i.e. trigger#0 = at time 0, trigger #1 = 60000msec, #2 = 120000, #3 = 180000, etc. and the trigger#0 at time 0 fires my job which takes 130000msec. With a plain Job, this would execute triggers #1 and #2 while job trigger #0 is still running. With a StatefulJob, this would execute triggers #1 and #2 in order, immediately after #0 finishes at 130000. I don't want that, I want #1 and #2 not to run and the next trigger that runs a job should take place at #3 (180000msec). So I still have to do something else with StatefulJob to get it to work the way I want, so I don't see much of an advantage to using it. Use a TriggerListener to return true from vetoJobExecution(). Although implementing the interface seems straightforward, I have to figure out how to setup one instance of a TriggerListener declaratively. Can't find the docs for the xml file. Use a static shared thread-safe object (e.g. a semaphore or whatever) owned by my class that implements Job. I don't like the idea of using singletons via the static keyword under Tomcat/Quartz, not sure if there are side effects. Also I really don't want them to be true singletons, just something that is associated with a particular job definition. Implement my own Trigger which extends SimpleTrigger and contains shared state that could run its own TriggerListener. Again, I don't know how to setup the XML file to use this trigger rather than the standard <trigger><simple>...</simple></trigger>.

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• If statement within If statement's else

  - by maebe

  Still new to Java/android so trying to figure out the best way to code a multilevel if statement. What I'm trying to do is for a combat system that needs to check if player/npc is alive. If they are alive it then will check to see if they scored a critical hit. If they didn't critical hit then will see if they hit or missed. combat = mydbhelper.getCombat(); startManagingCursor(combat); if(playerCurHp == 0){ combat.moveToPosition(11); npcCombatStory = combat.getString(combat.getColumnIndex(dbhelper.KEY_COMBATDESC));} else{ if(playerCritFlag.equals("Critical")){ combat.moveToPosition(2); playerCombatStory = combat.getString(combat.getColumnIndex(dbhelper.KEY_COMBATDESC));} else{ if(playerHitFlag.equals("Hit")){ combat.moveToPosition(1); playerCombatStory = combat.getString(combat.getColumnIndex(dbhelper.KEY_COMBATDESC));} if(playerHitFlag.equals("Miss")){ combat.moveToPosition(3); playerCombatStory = combat.getString(combat.getColumnIndex(dbhelper.KEY_COMBATDESC));} }} if (npcCurHp == 0){ combat.moveToPosition(10); npcCombatStory = combat.getString(combat.getColumnIndex(dbhelper.KEY_COMBATDESC));} else{ if(npcCritFlag.equals("Critical")){ combat.moveToPosition(5); npcCombatStory = combat.getString(combat.getColumnIndex(dbhelper.KEY_COMBATDESC));} else{ if(npcHitFlag.equals("Hit")){ combat.moveToPosition(4); npcCombatStory = combat.getString(combat.getColumnIndex(dbhelper.KEY_COMBATDESC));} if(npcHitFlag.equals("Miss")){ combat.moveToPosition(6); npcCombatStory = combat.getString(combat.getColumnIndex(dbhelper.KEY_COMBATDESC));} }} } Is what I'm using. Was working when I had the if statements all separate. But it would check each one and do actions I don't need (If they hit, pull String, if crit pull another, then if dead pull again). Trying to make it stop when it finds the "Flag" that matches. When doing my rolls if the player hits it sets the flag to "Hit" like below code. Random attackRandom = new Random(); int attackRoll = attackRandom.nextInt(100); totalAtt = attackRoll + bonusAttack + weaponAtt + stanceAtt; Random defensiveRandom = new Random(); int defenseRoll = defensiveRandom.nextInt(100); npcDef = defenseRoll + npcDodge + npcBonusDodge; if (totalAtt > npcDef){ playerHitFlag = "Hit"; playerDamage();} else{playerHitFlag = "Miss"; npcAttack();} At the end it takes these playerCombatStory and npcCombatStory strings and uses them to setText to show the player what happened on that turn of combat.

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• Implementing events to communicate between two processes - C

  - by Jamie Keeling

  Hello all! I have an application consisting of two windows, one communicates to the other and sends it a struct constaining two integers (In this case two rolls of a dice). I will be using events for the following circumstances: Process a sends data to process b, process b displays data Process a closes, in turn closing process b Process b closes a, in turn closing process a I have noticed that if the second process is constantly waiting for the first process to send data then the program will be just sat waiting, which is where the idea of implementing threads on each process occurred and I have started to implement this already. The problem i'm having is that I don't exactly have a lot of experience with threads and events so I'm not sure of the best way to actually implement what I want to do. Following is a small snippet of what I have so far in the producer application; Create thread: case IDM_FILE_ROLLDICE: { hDiceRoll = CreateThread( NULL, // lpThreadAttributes (default) 0, // dwStackSize (default) ThreadFunc(hMainWindow), // lpStartAddress NULL, // lpParameter 0, // dwCreationFlags &hDiceID // lpThreadId (returned by function) ); } break; The data being sent to the other process: DWORD WINAPI ThreadFunc(LPVOID passedHandle) { HANDLE hMainHandle = *((HANDLE*)passedHandle); WCHAR buffer[256]; LPCTSTR pBuf; LPVOID lpMsgBuf; LPVOID lpDisplayBuf; struct diceData storage; HANDLE hMapFile; DWORD dw; //Roll dice and store results in variable storage = RollDice(); hMapFile = CreateFileMapping( (HANDLE)0xFFFFFFFF, // use paging file NULL, // default security PAGE_READWRITE, // read/write access 0, // maximum object size (high-order DWORD) BUF_SIZE, // maximum object size (low-order DWORD) szName); // name of mapping object if (hMapFile == NULL) { dw = GetLastError(); MessageBox(hMainHandle,L"Could not create file mapping object",L"Error",MB_OK); return 1; } pBuf = (LPTSTR) MapViewOfFile(hMapFile, // handle to map object FILE_MAP_ALL_ACCESS, // read/write permission 0, 0, BUF_SIZE); if (pBuf == NULL) { MessageBox(hMainHandle,L"Could not map view of file",L"Error",MB_OK); CloseHandle(hMapFile); return 1; } CopyMemory((PVOID)pBuf, &storage, (_tcslen(szMsg) * sizeof(TCHAR))); //_getch(); MessageBox(hMainHandle,L"Completed!",L"Success",MB_OK); UnmapViewOfFile(pBuf); return 0; } I'm trying to find out how I would integrate an event with the threaded code to signify to the other process that something has happened, I've seen an MSDN article on using events but it's just confused me if anything, I'm coming up on empty whilst searching on the internet too. Thanks for any help Edit: I can only use the Create/Set/Open methods for events, sorry for not mentioning it earlier.

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• Using events in threads between processes - C

  - by Jamie Keeling

  Hello all! I have an application consisting of two windows, one communicates to the other and sends it a struct constaining two integers (In this case two rolls of a dice). I will be using events for the following circumstances: Process a sends data to process b, process b displays data Process a closes, in turn closing process b Process b closes a, in turn closing process a I have noticed that if the second process is constantly waiting for the first process to send data then the program will be just sat waiting, which is where the idea of implementing threads on each process occurred and I have started to implement this already. The problem i'm having is that I don't exactly have a lot of experience with threads and events so I'm not sure of the best way to actually implement what I want to do. Following is a small snippet of what I have so far in the producer application; Create thread: case IDM_FILE_ROLLDICE: { hDiceRoll = CreateThread( NULL, // lpThreadAttributes (default) 0, // dwStackSize (default) ThreadFunc(hMainWindow), // lpStartAddress NULL, // lpParameter 0, // dwCreationFlags &hDiceID // lpThreadId (returned by function) ); } break; The data being sent to the other process: DWORD WINAPI ThreadFunc(LPVOID passedHandle) { HANDLE hMainHandle = *((HANDLE*)passedHandle); WCHAR buffer[256]; LPCTSTR pBuf; LPVOID lpMsgBuf; LPVOID lpDisplayBuf; struct diceData storage; HANDLE hMapFile; DWORD dw; //Roll dice and store results in variable storage = RollDice(); hMapFile = CreateFileMapping( (HANDLE)0xFFFFFFFF, // use paging file NULL, // default security PAGE_READWRITE, // read/write access 0, // maximum object size (high-order DWORD) BUF_SIZE, // maximum object size (low-order DWORD) szName); // name of mapping object if (hMapFile == NULL) { dw = GetLastError(); MessageBox(hMainHandle,L"Could not create file mapping object",L"Error",MB_OK); return 1; } pBuf = (LPTSTR) MapViewOfFile(hMapFile, // handle to map object FILE_MAP_ALL_ACCESS, // read/write permission 0, 0, BUF_SIZE); if (pBuf == NULL) { MessageBox(hMainHandle,L"Could not map view of file",L"Error",MB_OK); CloseHandle(hMapFile); return 1; } CopyMemory((PVOID)pBuf, &storage, (_tcslen(szMsg) * sizeof(TCHAR))); //_getch(); MessageBox(hMainHandle,L"Completed!",L"Success",MB_OK); UnmapViewOfFile(pBuf); return 0; } I'm trying to find out how I would integrate an event with the threaded code to signify to the other process that something has happened, I've seen an MSDN article on using events but it's just confused me if anything, I'm coming up on empty whilst searching on the internet too. Thanks for any help Edit: I can only use the Create/Set/Open methods for events, sorry for not mentioning it earlier.

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• Ideas on implementing threads and cross process communication. - C

  - by Jamie Keeling

  Hello all! I have an application consisting of two windows, one communicates to the other and sends it a struct constaining two integers (In this case two rolls of a dice). I will be using events for the following circumstances: Process a sends data to process b, process b displays data Process a closes, in turn closing process b Process b closes a, in turn closing process a I have noticed that if the second process is constantly waiting for the first process to send data then the program will be just sat waiting, which is where the idea of implementing threads on each process occured. I have already implemented a thread on the first process which currently creates the data to send to the second process and makes it available to the second process. The problem i'm having is that I don't exactly have a lot of experience with threads and events so I'm not sure of the best way to actually implement what I want to do. Following is a small snippet of what I have so far in the producer application; Rolling the dice and sending the data: case IDM_FILE_ROLLDICE: { hDiceRoll = CreateThread( NULL, // lpThreadAttributes (default) 0, // dwStackSize (default) ThreadFunc(hMainWindow), // lpStartAddress NULL, // lpParameter 0, // dwCreationFlags &hDiceID // lpThreadId (returned by function) ); } break; The data being sent to the other process: DWORD WINAPI ThreadFunc(LPVOID passedHandle) { HANDLE hMainHandle = *((HANDLE*)passedHandle); WCHAR buffer[256]; LPCTSTR pBuf; LPVOID lpMsgBuf; LPVOID lpDisplayBuf; struct diceData storage; HANDLE hMapFile; DWORD dw; //Roll dice and store results in variable storage = RollDice(); hMapFile = CreateFileMapping( (HANDLE)0xFFFFFFFF, // use paging file NULL, // default security PAGE_READWRITE, // read/write access 0, // maximum object size (high-order DWORD) BUF_SIZE, // maximum object size (low-order DWORD) szName); // name of mapping object if (hMapFile == NULL) { dw = GetLastError(); MessageBox(hMainHandle,L"Could not create file mapping object",L"Error",MB_OK); return 1; } pBuf = (LPTSTR) MapViewOfFile(hMapFile, // handle to map object FILE_MAP_ALL_ACCESS, // read/write permission 0, 0, BUF_SIZE); if (pBuf == NULL) { MessageBox(hMainHandle,L"Could not map view of file",L"Error",MB_OK); CloseHandle(hMapFile); return 1; } CopyMemory((PVOID)pBuf, &storage, (_tcslen(szMsg) * sizeof(TCHAR))); //_getch(); MessageBox(hMainHandle,L"Completed!",L"Success",MB_OK); UnmapViewOfFile(pBuf); return 0; } I'd like to think I am at least on the right lines, although for some reason when the application finishes creating the thread it hits the return DefWindowProc(hMainWindow, message, wParam, lParam); it crashes saying there's no more source code for the current location. I know there are certain ways to implement things but as I've mentioned I'm not sure if i'm doing this the right way, has anybody else tried to do the same thing? Thanks!

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• How To Remove People and Objects From Photographs In Photoshop

  - by Eric Z Goodnight

  You might think that it’s a complicated process to remove objects from photographs. But really Photoshop makes it quite simple, even when removing all traces of a person from digital photographs. Read on to see just how easy it is. Photoshop was originally created to be an image editing program, and it excels at it. With hardly any Photoshop experience, any beginner can begin removing objects or people from their photos. Have some friends that photobombed an otherwise great pic? Tell them to say their farewells, because here’s how to get rid of them with Photoshop! Tools for Removing Objects Removing an object is not really “magical” work. Your goal is basically to cover up the information you don’t want in an image with information you do want. In this sample image, we want to remove the cigar smoking man, and leave the geisha. Here’s a couple of the tools that can be useful to work with when attempting this kind of task. Clone Stamp and Pattern Stamp Tool: Samples parts of your image from your background, and allows you to paint into your image with your mouse or stylus. Eraser and Brush Tools: Paint flat colors and shapes, and erase cloned layers of image information. Basic, down and dirty photo editing tools. Pen, Quick Selection, Lasso, and Crop tools: Select, isolate, and remove parts of your image with these selection tools. All useful in their own way. Some, like the pen tool, are nightmarishly tough on beginners. Remove a Person with the Clone Stamp Tool (Video) The video above uses the Clone Stamp tool to sample and paint with the background texture. It’s a simple tool to use, although it can be confusing, possibly counter-intuitive. Here’s some pointers, in addition to the video above. Select shortcut key to choose the Clone tool stamp from the Tools Panel. Always create a copy of your background layer before doing heavy edits by right clicking on the background in your Layers Panel and selecting “Duplicate.” Hold with the Clone Tool selected, and click anywhere in your image to sample that area. When you’re sampling an area, your cursor is “Aligned” with your sample area. When you paint, your sample area moves. You can turn the “Aligned” setting off by clicking the in the Options Panel at the top of your screen if you want. Change your brush size and hardness as shown in the video by right-clicking in your image. Use your lasso to copy and paste pieces of your image in order to cover up any parts that seem appropriate. Photoshop Magic with the “Content-Aware Fill” One of the hallmark features of CS5 is the “Content-Aware Fill.” Content aware fill can be an excellent shortcut to removing objects and even people in Photoshop, but it is somewhat limited, and can get confused. Here’s a basic rundown on how it works. Select an object using your Lasso tool, shortcut key . The Lasso works fine as this selection can be rough. Navigate to Edit > Fill, and select “Content-Aware,” as illustrated above, from the pull-down menu. It’s surprisingly simple. After some processing, Photoshop has done the work of removing the object for you. It takes a few moments, and it is not perfect, so be prepared to touch it up with some Copy-Paste, or some Clone stamp action. Content Aware Fill Has Its Limits Keep in mind that the Content Aware Fill is meant to be used with other techniques in mind. It doesn’t always perform perfectly, but can give you a great starting point. Take this image for instance. It is actually plausible to hide this figure and make this image look like he was never there at all. With a selection made with the Lasso tool, navigate to Edit > Fill and select “Content Aware” again. The result is surprisingly good, but as you can see, worthy of some touch up. With a result like this one, you’ll have to get your hands dirty with copy-paste to create believable lines in the background. With many photographs, Content Aware Fill will simply get confused and give you results you won’t be happy with. Additional Touch Up for Bad Background Textures with the Pattern Stamp Tool For the perfectionist, cleaning up the lumpy looking textures that the Clone Stamp can leave is fairly simple using the Pattern Stamp Tool. Sample an piece of your image with your Marquee Tool, shortcut key . Navigate to Edit > Define Pattern to create a new Pattern from your selection. Click OK to continue. Click and hold down on the Clone Stamp tool in your Tools Panel until you can select the Pattern Stamp Tool. Pick your new pattern from the Options at the top of your screen, in the Options Panel. Then simply right click in your image in order to pick as soft a brush as possible to paint with. Paint into your image until your background is as smooth as you want it to be, making your painted out object more and more invisible. If you get lines from your repeated texture, experiment turning the on and off and paint over them. In addition to this, simple use of the Crop Tool, shortcut , can recompose an image, making it look as if it never had another object in it at all. Combine these techniques to find a method that works best for your images. Have questions or comments concerning Graphics, Photos, Filetypes, or Photoshop? Send your questions to [email protected], and they may be featured in a future How-To Geek Graphics article. Image Credits: Geisha Kyoto Gion by Todd Laracuenta via Wikipedia, used under Creative Commons. Moai Rano raraku by Aurbina, in Public Domain. Chris Young visits Wrigley by TonyTheTiger, via Wikipedia, used under Creative Commons. Latest Features How-To Geek ETC Ask How-To Geek: How Can I Monitor My Bandwidth Usage? Internet Explorer 9 RC Now Available: Here’s the Most Interesting New Stuff Here’s a Super Simple Trick to Defeating Fake Anti-Virus Malware How to Change the Default Application for Android Tasks Stop Believing TV’s Lies: The Real Truth About "Enhancing" Images The How-To Geek Valentine’s Day Gift Guide CyanogenMod Updates; Rolls out Android 2.3 to the Less Fortunate MyPaint is an Open-Source Graphics App for Digital Painters Can the Birds and Pigs Really Be Friends in the End? [Angry Birds Video] Add the 2D Version of the New Unity Interface to Ubuntu 10.10 and 11.04 MightyMintyBoost Is a 3-in-1 Gadget Charger Watson Ties Against Human Jeopardy Opponents

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• How Visual Studio 2010 and Team Foundation Server enable Compliance

  - by Martin Hinshelwood

  One of the things that makes Team Foundation Server (TFS) the most powerful Application Lifecycle Management (ALM) platform is the traceability it provides to those that use it. This traceability is crucial to enable many companies to adhere to many of the Compliance regulations to which they are bound (e.g. CFR 21 Part 11 or Sarbanes–Oxley.)   From something as simple as relating Tasks to Check-in’s or being able to see the top 10 files in your codebase that are causing the most Bugs, to identifying which Bugs and Requirements are in which Release. All that information is available and more in TFS. Although all of this tradability is available within TFS you do need to understand that it is not for free. Well… I say that, but if you are using TFS properly you will have this information with no additional work except for firing up the reporting. Using Visual Studio ALM and Team Foundation Server you can relate every line of code changes all the way up to requirements and back down through Test Cases to the Test Results. Figure: The only thing missing is Build In order to build the relationship model below we need to examine how each of the relationships get there. Each member of your team from programmer to tester and Business Analyst to Business have their roll to play to knit this together. Figure: The relationships required to make this work can get a little confusing If Build is added to this to relate Work Items to Builds and with knowledge of which builds are in which environments you can easily identify what is contained within a Release. Figure: How are things progressing Along with the ability to produce the progress and trend reports the tractability that is built into TFS can be used to fulfil most audit requirements out of the box, and augmented to fulfil the rest. In order to understand the relationships, lets look at each of the important Artifacts and how they are associated with each other… Requirements – The root of all knowledge Requirements are the thing that the business cares about delivering. These could be derived as User Stories or Business Requirements Documents (BRD’s) but they should be what the Business asks for. Requirements can be related to many of the Artifacts in TFS, so lets look at the model: Figure: If the centre of the world was a requirement We can track which releases Requirements were scheduled in, but this can change over time as more details come to light. Figure: Who edited the Requirement and when There is also the ability to query Work Items based on the History of changed that were made to it. This is particularly important with Requirements. It might not be enough to say what Requirements were completed in a given but also to know which Requirements were ever assigned to a particular release. Figure: Some magic required, but result still achieved As an augmentation to this it is also possible to run a query that shows results from the past, just as if we had a time machine. You can take any Query in the system and add a “Asof” clause at the end to query historical data in the operational store for TFS. select <fields> from WorkItems [where <condition>] [order by <fields>] [asof <date>] Figure: Work Item Query Language (WIQL) format In order to achieve this you do need to save the query as a *.wiql file to your local computer and edit it in notepad, but one imported into TFS you run it any time you want. Figure: Saving Queries locally can be useful All of these Audit features are available throughout the Work Item Tracking (WIT) system within TFS. Tasks – Where the real work gets done Tasks are the work horse of the development team, but they only as useful as Excel if you do not relate them properly to other Artifacts. Figure: The Task Work Item Type has its own relationships Requirements should be broken down into Tasks that the development team work from to build what is required by the business. This may be done by a small dedicated group or by everyone that will be working on the software team but however it happens all of the Tasks create should be a Child of a Requirement Work Item Type. Figure: Tasks are related to the Requirement Tasks should be used to track the day-to-day activities of the team working to complete the software and as such they should be kept simple and short lest developers think they are more trouble than they are worth. Figure: Task Work Item Type has a narrower purpose Although the Task Work Item Type describes the work that will be done the actual development work involves making changes to files that are under Source Control. These changes are bundled together in a single atomic unit called a Changeset which is committed to TFS in a single operation. During this operation developers can associate Work Item with the Changeset. Figure: Tasks are associated with Changesets   Changesets – Who wrote this crap Changesets themselves are just an inventory of the changes that were made to a number of files to complete a Task. Figure: Changesets are linked by Tasks and Builds   Figure: Changesets tell us what happened to the files in Version Control Although comments can be changed after the fact, the inventory and Work Item associations are permanent which allows us to Audit all the way down to the individual change level. Figure: On Check-in you can resolve a Task which automatically associates it Because of this we can view the history on any file within the system and see how many changes have been made and what Changesets they belong to. Figure: Changes are tracked at the File level What would be even more powerful would be if we could view these changes super imposed over the top of the lines of code. Some people call this a blame tool because it is commonly used to find out which of the developers introduced a bug, but it can also be used as another method of Auditing changes to the system. Figure: Annotate shows the lines the Annotate functionality allows us to visualise the relationship between the individual lines of code and the Changesets. In addition to this you can create a Label and apply it to a version of your version control. The problem with Label’s is that they can be changed after they have been created with no tractability. This makes them practically useless for any sort of compliance audit. So what do you use? Branches – And why we need them Branches are a really powerful tool for development and release management, but they are most important for audits. Figure: One way to Audit releases The R1.0 branch can be created from the Label that the Build creates on the R1 line when a Release build was created. It can be created as soon as the Build has been signed of for release. However it is still possible that someone changed the Label between this time and its creation. Another better method can be to explicitly link the Build output to the Build. Builds – Lets tie some more of this together Builds are the glue that helps us enable the next level of tractability by tying everything together. Figure: The dashed pieces are not out of the box but can be enabled When the Build is called and starts it looks at what it has been asked to build and determines what code it is going to get and build. Figure: The folder identifies what changes are included in the build The Build sets a Label on the Source with the same name as the Build, but the Build itself also includes the latest Changeset ID that it will be building. At the end of the Build the Build Agent identifies the new Changesets it is building by looking at the Check-ins that have occurred since the last Build. Figure: What changes have been made since the last successful Build It will then use that information to identify the Work Items that are associated with all of the Changesets Changesets are associated with Build and change the “Integrated In” field of those Work Items . Figure: Find all of the Work Items to associate with The “Integrated In” field of all of the Work Items identified by the Build Agent as being integrated into the completed Build are updated to reflect the Build number that successfully integrated that change. Figure: Now we know which Work Items were completed in a build Now that we can link a single line of code changed all the way back through the Task that initiated the action to the Requirement that started the whole thing and back down to the Build that contains the finished Requirement. But how do we know wither that Requirement has been fully tested or even meets the original Requirements? Test Cases – How we know we are done The only way we can know wither a Requirement has been completed to the required specification is to Test that Requirement. In TFS there is a Work Item type called a Test Case Test Cases enable two scenarios. The first scenario is the ability to track and validate Acceptance Criteria in the form of a Test Case. If you agree with the Business a set of goals that must be met for a Requirement to be accepted by them it makes it both difficult for them to reject a Requirement when it passes all of the tests, but also provides a level of tractability and validation for audit that a feature has been built and tested to order. Figure: You can have many Acceptance Criteria for a single Requirement It is crucial for this to work that someone from the Business has to sign-off on the Test Case moving from the  “Design” to “Ready” states. The Second is the ability to associate an MS Test test with the Test Case thereby tracking the automated test. This is useful in the circumstance when you want to Track a test and the test results of a Unit Test designed to test the existence of and then re-existence of a a Bug. Figure: Associating a Test Case with an automated Test Although it is possible it may not make sense to track the execution of every Unit Test in your system, there are many Integration and Regression tests that may be automated that it would make sense to track in this way. Bug – Lets not have regressions In order to know wither a Bug in the application has been fixed and to make sure that it does not reoccur it needs to be tracked. Figure: Bugs are the centre of their own world If the fix to a Bug is big enough to require that it is broken down into Tasks then it is probably a Requirement. You can associate a check-in with a Bug and have it tracked against a Build. You would also have one or more Test Cases to prove the fix for the Bug. Figure: Bugs have many associations This allows you to track Bugs / Defects in your system effectively and report on them. Change Request – I am not a feature In the CMMI Process template Change Requests can also be easily tracked through the system. In some cases it can be very important to track Change Requests separately as an Auditor may want to know what was changed and who authorised it. Again and similar to Bugs, if the Change Request is big enough that it would require to be broken down into Tasks it is in reality a new feature and should be tracked as a Requirement. Figure: Make sure your Change Requests only Affect Requirements and not rewrite them Conclusion Visual Studio 2010 and Team Foundation Server together provide an exceptional Application Lifecycle Management platform that can help your team comply with even the harshest of Compliance requirements while still enabling them to be Agile. Most Audits are heavy on required documentation but most of that information is captured for you as long a you do it right. You don’t even need every team member to understand it all as each of the Artifacts are relevant to a different type of team member. Business Analysts manage Requirements and Change Requests Programmers manage Tasks and check-in against Change Requests and Bugs Testers manage Bugs and Test Cases Build Masters manage Builds Although there is some crossover there are still rolls or “hats” that are worn. Do you thing this is all achievable? Have I missed anything that you think should be there?

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• Qt QAbstractButton setDown interferes with grabMouse

  - by edA-qa mort-ora-y

  I have some weird behaviour in Qt that seems like a defect. I'd like to know if anybody has a good workaround. I have a popup widget that contains many buttons in it. The user activates the popup by pressing the mouse button down. The popup widget calls grabMouse when shown. It gets all the mouse events. As it rolls over a button it calls setDown(true) on the button. Now however, when the mouse button is released the popup widget does not get the mouseReleaseEvent, that goes to the button. That is, calling setDown(true) on a button causes the button to steal mouse events, bypassing the grabMouse in the popup widget. I've looked at the source code for setDown but I can't see anything there that would do it directly. I also notice however that sometimes a button gets a hover event, sometimes not. I would assume it would never get those events when the mouse is grabbed. //g++ -o grab_lost grab_lost.cpp -lQtCore -lQtGui -I /usr/include/qt4/ -I /usr/include/qt4/QtCore -I /usr/include/qt4/QtGui /** Demonstrates the defect of losing the mouse. Run the program and: 1. Press mouse anywhere 2. release in purple block (not on X) 3. Release message written (GrabLost receives the mouseReleaseEvent) For defect: 1. Pree mouse anywhere 2. Release inside the X button 3. button is clicked, no release message (GrabLost does not get the mouseReleaseEvent) */ #include <QWidget> #include <QPushButton> #include <QApplication> #include <QMouseEvent> #include <QPainter> class GrabLost : public QWidget { QPushButton * btn; public: GrabLost( QWidget * parent = 0) : QWidget( parent, Qt::Popup ) { btn = new QPushButton( "X", this ); setMouseTracking( true ); } protected: void showEvent( QShowEvent * ev ) { QWidget::showEvent( ev ); grabMouse(); } void closeEvent( QCloseEvent * ev ) { releaseMouse(); QWidget::closeEvent( ev ); } void hideEvent( QHideEvent * ev ) { releaseMouse(); QWidget::hideEvent( ev ); } void mouseReleaseEvent( QMouseEvent * ev ) { qDebug( "mouseRelease" ); close(); } void mouseMoveEvent( QMouseEvent * ev ) { QWidget * w = childAt( ev->pos() ); bool ours = dynamic_cast<QPushButton*>( w ) == btn; btn->setDown( ours ); } void paintEvent( QPaintEvent * ev ) { //just to show where the widget is QPainter pt( this ); pt.setPen( QColor( 0,0,0 ) ); pt.setBrush( QColor( 128,0,128) ); pt.drawRect( 0, 0, size().width(), size().height() ); } }; class GrabMe : public QWidget { protected: void mousePressEvent( QMouseEvent * ev ) { GrabLost * gl = new GrabLost(); gl->resize( 100, 100 ); QPoint at( mapToGlobal( ev->pos() ) ); gl->move( at.x() - 50, at.y() - 50 ); gl->show(); } }; int main( int argc, char** argv ) { QApplication app( argc, argv ); GrabMe * gm = new GrabMe(); gm->move( 100, 100 ); gm->resize( 300, 300 ); gm->show(); app.exec(); return 0; }

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• Loading jQuery Consistently in a .NET Web App

  - by Rick Strahl

  One thing that frequently comes up in discussions when using jQuery is how to best load the jQuery library (as well as other commonly used and updated libraries) in a Web application. Specifically the issue is the one of versioning and making sure that you can easily update and switch versions of script files with application wide settings in one place and having your script usage reflect those settings in the entire application on all pages that use the script. Although I use jQuery as an example here, the same concepts can be applied to any script library - for example in my Web libraries I use the same approach for jQuery.ui and my own internal jQuery support library. The concepts used here can be applied both in WebForms and MVC. Loading jQuery Properly From CDN Before we look at a generic way to load jQuery via some server logic, let me first point out my preferred way to embed jQuery into the page. I use the Google CDN to load jQuery and then use a fallback URL to handle the offline or no Internet connection scenario. Why use a CDN? CDN links tend to be loaded more quickly since they are very likely to be cached in user's browsers already as jQuery CDN is used by many, many sites on the Web. Using a CDN also removes load from your Web server and puts the load bearing on the CDN provider - in this case Google - rather than on your Web site. On the downside, CDN links gives the provider (Google, Microsoft) yet another way to track users through their Web usage. Here's how I use jQuery CDN plus a fallback link on my WebLog for example: <!DOCTYPE HTML> <html> <head> <script src="//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js"></script> <script> if (typeof (jQuery) == 'undefined') document.write(unescape("%3Cscript " + "src='/Weblog/wwSC.axd?r=Westwind.Web.Controls.Resources.jquery.js' %3E%3C/script%3E")); </script> <title>Rick Strahl's Web Log</title> ... </head>   You can see that the CDN is referenced first, followed by a small script block that checks to see whether jQuery was loaded (jQuery object exists). If it didn't load another script reference is added to the document dynamically pointing to a backup URL. In this case my backup URL points at a WebResource in my Westwind.Web  assembly, but the URL can also be local script like src="/scripts/jquery.min.js". Important: Use the proper Protocol/Scheme for  for CDN Urls [updated based on comments] If you're using a CDN to load an external script resource you should always make sure that the script is loaded with the same protocol as the parent page to avoid mixed content warnings by the browser. You don't want to load a script link to an http:// resource when you're on an https:// page. The easiest way to use this is by using a protocol relative URL: <script src="//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js"></script> which is an easy way to load resources from other domains. This URL syntax will automatically use the parent page's protocol (or more correctly scheme). As long as the remote domains support both http:// and https:// access this should work. BTW this also works in CSS (with some limitations) and links. BTW, I didn't know about this until it was pointed out in the comments. This is a very useful feature for many things - ah the benefits of my blog to myself :-) Version Numbers When you use a CDN you notice that you have to reference a specific version of jQuery. When using local files you may not have to do this as you can rename your private copy of jQuery.js, but for CDN the references are always versioned. The version number is of course very important to ensure you getting the version you have tested with, but it's also important to the provider because it ensures that cached content is always correct. If an existing file was updated the updates might take a very long time to get past the locally cached content and won't refresh properly. The version number ensures you get the right version and not some cached content that has been changed but not updated in your cache. On the other hand version numbers also mean that once you decide to use a new version of the script you now have to change all your script references in your pages. Depending on whether you use some sort of master/layout page or not this may or may not be easy in your application. Even if you do use master/layout pages, chances are that you probably have a few of them and at the very least all of those have to be updated for the scripts. If you use individual pages for all content this issue then spreads to all of your pages. Search and Replace in Files will do the trick, but it's still something that's easy to forget and worry about. Personaly I think it makes sense to have a single place where you can specify common script libraries that you want to load and more importantly which versions thereof and where they are loaded from. Loading Scripts via Server Code Script loading has always been important to me and as long as I can remember I've always built some custom script loading routines into my Web frameworks. WebForms makes this fairly easy because it has a reasonably useful script manager (ClientScriptManager and the ScriptManager) which allow injecting script into the page easily from anywhere in the Page cycle. What's nice about these components is that they allow scripts to be injected by controls so components can wrap up complex script/resource dependencies more easily without having to require long lists of CSS/Scripts/Image includes. In MVC or pure script driven applications like Razor WebPages  the process is more raw, requiring you to embed script references in the right place. But its also more immediate - it lets you know exactly which versions of scripts to use because you have to manually embed them. In WebForms with different controls loading resources this often can get confusing because it's quite possible to load multiple versions of the same script library into a page, the results of which are less than optimal… In this post I look a simple routine that embeds jQuery into the page based on a few application wide configuration settings. It returns only a string of the script tags that can be manually embedded into a Page template. It's a small function that merely a string of the script tags shown at the begging of this post along with some options on how that string is comprised. You'll be able to specify in one place which version loads and then all places where the help function is used will automatically reflect this selection. Options allow specification of the jQuery CDN Url, the fallback Url and where jQuery should be loaded from (script folder, Resource or CDN in my case). While this is specific to jQuery you can apply this to other resources as well. For example I use a similar approach with jQuery.ui as well using practically the same semantics. Providing Resources in ControlResources In my Westwind.Web Web utility library I have a class called ControlResources which is responsible for holding resource Urls, resource IDs and string contants that reference those resource IDs. The library also provides a few helper methods for loading common scriptscripts into a Web page. There are specific versions for WebForms which use the ClientScriptManager/ScriptManager and script link methods that can be used in any .NET technology that can embed an expression into the output template (or code for that matter). The ControlResources class contains mostly static content - references to resources mostly. But it also contains a few static properties that configure script loading: A Script LoadMode (CDN, Resource, or script url) A default CDN Url A fallback url They are  static properties in the ControlResources class: public class ControlResources { /// <summary> /// Determines what location jQuery is loaded from /// </summary> public static JQueryLoadModes jQueryLoadMode = JQueryLoadModes.ContentDeliveryNetwork; /// <summary> /// jQuery CDN Url on Google /// </summary> public static string jQueryCdnUrl = "//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js"; /// <summary> /// jQuery CDN Url on Google /// </summary> public static string jQueryUiCdnUrl = "//ajax.googleapis.com/ajax/libs/jqueryui/1.8.16/jquery-ui.min.js"; /// <summary> /// jQuery UI fallback Url if CDN is unavailable or WebResource is used /// Note: The file needs to exist and hold the minimized version of jQuery ui /// </summary> public static string jQueryUiLocalFallbackUrl = "~/scripts/jquery-ui.min.js"; } These static properties are fixed values that can be changed at application startup to reflect your preferences. Since they're static they are application wide settings and respected across the entire Web application running. It's best to set these default in Application_Init or similar startup code if you need to change them for your application: protected void Application_Start(object sender, EventArgs e) { // Force jQuery to be loaded off Google Content Network ControlResources.jQueryLoadMode = JQueryLoadModes.ContentDeliveryNetwork; // Allow overriding of the Cdn url ControlResources.jQueryCdnUrl = "http://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js"; // Route to our own internal handler App.OnApplicationStart(); } With these basic settings in place you can then embed expressions into a page easily. In WebForms use: <!DOCTYPE html> <html> <head runat="server"> <%= ControlResources.jQueryLink() %> <script src="scripts/ww.jquery.min.js"></script> </head> In Razor use: <!DOCTYPE html> <html> <head> @Html.Raw(ControlResources.jQueryLink()) <script src="scripts/ww.jquery.min.js"></script> </head> Note that in Razor you need to use @Html.Raw() to force the string NOT to escape. Razor by default escapes string results and this ensures that the HTML content is properly expanded as raw HTML text. Both the WebForms and Razor output produce: <!DOCTYPE html> <html> <head> <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js" type="text/javascript"></script> <script type="text/javascript"> if (typeof (jQuery) == 'undefined') document.write(unescape("%3Cscript src='/WestWindWebToolkitWeb/WebResource.axd?d=-b6oWzgbpGb8uTaHDrCMv59VSmGhilZP5_T_B8anpGx7X-PmW_1eu1KoHDvox-XHqA1EEb-Tl2YAP3bBeebGN65tv-7-yAimtG4ZnoWH633pExpJor8Qp1aKbk-KQWSoNfRC7rQJHXVP4tC0reYzVw2&t=634535391996872492' type='text/javascript'%3E%3C/script%3E"));</script> <script src="scripts/ww.jquery.min.js"></script> </head> which produces the desired effect for both CDN load and fallback URL. The implementation of jQueryLink is pretty basic of course: /// <summary> /// Inserts a script link to load jQuery into the page based on the jQueryLoadModes settings /// of this class. Default load is by CDN plus WebResource fallback /// </summary> /// <param name="url"> /// An optional explicit URL to load jQuery from. Url is resolved. /// When specified no fallback is applied /// </param> /// <returns>full script tag and fallback script for jQuery to load</returns> public static string jQueryLink(JQueryLoadModes jQueryLoadMode = JQueryLoadModes.Default, string url = null) { string jQueryUrl = string.Empty; string fallbackScript = string.Empty; if (jQueryLoadMode == JQueryLoadModes.Default) jQueryLoadMode = ControlResources.jQueryLoadMode; if (!string.IsNullOrEmpty(url)) jQueryUrl = WebUtils.ResolveUrl(url); else if (jQueryLoadMode == JQueryLoadModes.WebResource) { Page page = new Page(); jQueryUrl = page.ClientScript.GetWebResourceUrl(typeof(ControlResources), ControlResources.JQUERY_SCRIPT_RESOURCE); } else if (jQueryLoadMode == JQueryLoadModes.ContentDeliveryNetwork) { jQueryUrl = ControlResources.jQueryCdnUrl; if (!string.IsNullOrEmpty(jQueryCdnUrl)) { // check if jquery loaded - if it didn't we're not online and use WebResource fallbackScript = @"<script type=""text/javascript"">if (typeof(jQuery) == 'undefined') document.write(unescape(""%3Cscript src='{0}' type='text/javascript'%3E%3C/script%3E""));</script>"; fallbackScript = string.Format(fallbackScript, WebUtils.ResolveUrl(ControlResources.jQueryCdnFallbackUrl)); } } string output = "<script src=\"" + jQueryUrl + "\" type=\"text/javascript\"></script>"; // add in the CDN fallback script code if (!string.IsNullOrEmpty(fallbackScript)) output += "\r\n" + fallbackScript + "\r\n"; return output; } There's one dependency here on WebUtils.ResolveUrl() which resolves Urls without access to a Page/Control (another one of those features that should be in the runtime, not in the WebForms or MVC engine). You can see there's only a little bit of logic in this code that deals with potentially different load modes. I can load scripts from a Url, WebResources or - my preferred way - from CDN. Based on the static settings the scripts to embed are composed to be returned as simple string <script> tag(s). I find this extremely useful especially when I'm not connected to the internet so that I can quickly swap in a local jQuery resource instead of loading from CDN. While CDN loading with the fallback works it can be a bit slow as the CDN is probed first before the fallback kicks in. Switching quickly in one place makes this trivial. It also makes it very easy once a new version of jQuery rolls around to move up to the new version and ensure that all pages are using the new version immediately. I'm not trying to make this out as 'the' definite way to load your resources, but rather provide it here as a pointer so you can maybe apply your own logic to determine where scripts come from and how they load. You could even automate this some more by using configuration settings or reading the locations/preferences out of some sort of data/metadata store that can be dynamically updated instead via recompilation. FWIW, I use a very similar approach for loading jQuery UI and my own ww.jquery library - the same concept can be applied to any kind of script you might be loading from different locations. Hopefully some of you find this a useful addition to your toolset. Resources Google CDN for jQuery Full ControlResources Source Code ControlResource Documentation Westwind.Web NuGet This method is part of the Westwind.Web library of the West Wind Web Toolkit or you can grab the Web library from NuGet and add to your Visual Studio project. This package includes a host of Web related utilities and script support features. © Rick Strahl, West Wind Technologies, 2005-2011Posted in ASP.NET  jQuery   Tweet (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• The Benefits of Smart Grid Business Software

  - by Sylvie MacKenzie, PMP

  Smart Grid Background What Are Smart Grids?Smart Grids use computer hardware and software, sensors, controls, and telecommunications equipment and services to: Link customers to information that helps them manage consumption and use electricity wisely. Enable customers to respond to utility notices in ways that help minimize the duration of overloads, bottlenecks, and outages. Provide utilities with information that helps them improve performance and control costs. What Is Driving Smart Grid Development? Environmental ImpactSmart Grid development is picking up speed because of the widespread interest in reducing the negative impact that energy use has on the environment. Smart Grids use technology to drive efficiencies in transmission, distribution, and consumption. As a result, utilities can serve customers’ power needs with fewer generating plants, fewer transmission and distribution assets,and lower overall generation. With the possible exception of wind farm sprawl, landscape preservation is one obvious benefit. And because most generation today results in greenhouse gas emissions, Smart Grids reduce air pollution and the potential for global climate change.Smart Grids also more easily accommodate the technical difficulties of integrating intermittent renewable resources like wind and solar into the grid, providing further greenhouse gas reductions. CostsThe ability to defer the cost of plant and grid expansion is a major benefit to both utilities and customers. Utilities do not need to use as many internal resources for traditional infrastructure project planning and management. Large T&D infrastructure expansion costs are not passed on to customers.Smart Grids will not eliminate capital expansion, of course. Transmission corridors to connect renewable generation with customers will require major near-term expenditures. Additionally, in the future, electricity to satisfy the needs of population growth and additional applications will exceed the capacity reductions available through the Smart Grid. At that point, expansion will resume—but with greater overall T&D efficiency based on demand response, load control, and many other Smart Grid technologies and business processes. Energy efficiency is a second area of Smart Grid cost saving of particular relevance to customers. The timely and detailed information Smart Grids provide encourages customers to limit waste, adopt energy-efficient building codes and standards, and invest in energy efficient appliances. Efficiency may or may not lower customer bills because customer efficiency savings may be offset by higher costs in generation fuels or carbon taxes. It is clear, however, that bills will be lower with efficiency than without it. Utility Operations Smart Grids can serve as the central focus of utility initiatives to improve business processes. Many utilities have long “wish lists” of projects and applications they would like to fund in order to improve customer service or ease staff’s burden of repetitious work, but they have difficulty cost-justifying the changes, especially in the short term. Adding Smart Grid benefits to the cost/benefit analysis frequently tips the scales in favor of the change and can also significantly reduce payback periods.Mobile workforce applications and asset management applications work together to deploy assets and then to maintain, repair, and replace them. Many additional benefits result—for instance, increased productivity and fuel savings from better routing. Similarly, customer portals that provide customers with near-real-time information can also encourage online payments, thus lowering billing costs. Utilities can and should include these cost and service improvements in the list of Smart Grid benefits. What Is Smart Grid Business Software? Smart Grid business software gathers data from a Smart Grid and uses it improve a utility’s business processes. Smart Grid business software also helps utilities provide relevant information to customers who can then use it to reduce their own consumption and improve their environmental profiles. Smart Grid Business Software Minimizes the Impact of Peak Demand Utilities must size their assets to accommodate their highest peak demand. The higher the peak rises above base demand: The more assets a utility must build that are used only for brief periods—an inefficient use of capital. The higher the utility’s risk profile rises given the uncertainties surrounding the time needed for permitting, building, and recouping costs. The higher the costs for utilities to purchase supply, because generators can charge more for contracts and spot supply during high-demand periods. Smart Grids enable a variety of programs that reduce peak demand, including: Time-of-use pricing and critical peak pricing—programs that charge customers more when they consume electricity during peak periods. Pilot projects indicate that these programs are successful in flattening peaks, thus ensuring better use of existing T&D and generation assets. Direct load control, which lets utilities reduce or eliminate electricity flow to customer equipment (such as air conditioners). Contracts govern the terms and conditions of these turn-offs. Indirect load control, which signals customers to reduce the use of on-premises equipment for contractually agreed-on time periods. Smart Grid business software enables utilities to impose penalties on customers who do not comply with their contracts. Smart Grids also help utilities manage peaks with existing assets by enabling: Real-time asset monitoring and control. In this application, advanced sensors safely enable dynamic capacity load limits, ensuring that all grid assets can be used to their maximum capacity during peak demand periods. Real-time asset monitoring and control applications also detect the location of excessive losses and pinpoint need for mitigation and asset replacements. As a result, utilities reduce outage risk and guard against excess capacity or “over-build”. Better peak demand analysis. As a result: Distribution planners can better size equipment (e.g. transformers) to avoid over-building. Operations engineers can identify and resolve bottlenecks and other inefficiencies that may cause or exacerbate peaks. As above, the result is a reduction in the tendency to over-build. Supply managers can more closely match procurement with delivery. As a result, they can fine-tune supply portfolios, reducing the tendency to over-contract for peak supply and reducing the need to resort to spot market purchases during high peaks. Smart Grids can help lower the cost of remaining peaks by: Standardizing interconnections for new distributed resources (such as electricity storage devices). Placing the interconnections where needed to support anticipated grid congestion. Smart Grid Business Software Lowers the Cost of Field Services By processing Smart Grid data through their business software, utilities can reduce such field costs as: Vegetation management. Smart Grids can pinpoint momentary interruptions and tree-caused outages. Spatial mash-up tools leverage GIS models of tree growth for targeted vegetation management. This reduces the cost of unnecessary tree trimming. Service vehicle fuel. Many utility service calls are “false alarms.” Checking meter status before dispatching crews prevents many unnecessary “truck rolls.” Similarly, crews use far less fuel when Smart Grid sensors can pinpoint a problem and mobile workforce applications can then route them directly to it. Smart Grid Business Software Ensures Regulatory Compliance Smart Grids can ensure compliance with private contracts and with regional, national, or international requirements by: Monitoring fulfillment of contract terms. Utilities can use one-hour interval meters to ensure that interruptible (“non-core”) customers actually reduce or eliminate deliveries as required. They can use the information to levy fines against contract violators. Monitoring regulations imposed on customers, such as maximum use during specific time periods. Using accurate time-stamped event history derived from intelligent devices distributed throughout the smart grid to monitor and report reliability statistics and risk compliance. Automating business processes and activities that ensure compliance with security and reliability measures (e.g. NERC-CIP 2-9). Grid Business Software Strengthens Utilities’ Connection to Customers While Reducing Customer Service Costs During outages, Smart Grid business software can: Identify outages more quickly. Software uses sensors to pinpoint outages and nested outage locations. They also permit utilities to ensure outage resolution at every meter location. Size outages more accurately, permitting utilities to dispatch crews that have the skills needed, in appropriate numbers. Provide updates on outage location and expected duration. This information helps call centers inform customers about the timing of service restoration. Smart Grids also facilitates display of outage maps for customer and public-service use. Smart Grids can significantly reduce the cost to: Connect and disconnect customers. Meters capable of remote disconnect can virtually eliminate the costs of field crews and vehicles previously required to change service from the old to the new residents of a metered property or disconnect customers for nonpayment. Resolve reports of voltage fluctuation. Smart Grids gather and report voltage and power quality data from meters and grid sensors, enabling utilities to pinpoint reported problems or resolve them before customers complain. Detect and resolve non-technical losses (e.g. theft). Smart Grids can identify illegal attempts to reconnect meters or to use electricity in supposedly vacant premises. They can also detect theft by comparing flows through delivery assets with billed consumption. Smart Grids also facilitate outreach to customers. By monitoring and analyzing consumption over time, utilities can: Identify customers with unusually high usage and contact them before they receive a bill. They can also suggest conservation techniques that might help to limit consumption. This can head off “high bill” complaints to the contact center. Note that such “high usage” or “additional charges apply because you are out of range” notices—frequently via text messaging—are already common among mobile phone providers. Help customers identify appropriate bill payment alternatives (budget billing, prepayment, etc.). Help customers find and reduce causes of over-consumption. There’s no waiting for bills in the mail before they even understand there is a problem. Utilities benefit not just through improved customer relations but also through limiting the size of bills from customers who might struggle to pay them. Where permitted, Smart Grids can open the doors to such new utility service offerings as: Monitoring properties. Landlords reduce costs of vacant properties when utilities notify them of unexpected energy or water consumption. Utilities can perform similar services for owners of vacation properties or the adult children of aging parents. Monitoring equipment. Power-use patterns can reveal a need for equipment maintenance. Smart Grids permit utilities to alert owners or managers to a need for maintenance or replacement. Facilitating home and small-business networks. Smart Grids can provide a gateway to equipment networks that automate control or let owners access equipment remotely. They also facilitate net metering, offering some utilities a path toward involvement in small-scale solar or wind generation. Prepayment plans that do not need special meters. Smart Grid Business Software Helps Customers Control Energy Costs There is no end to the ways Smart Grids help both small and large customers control energy costs. For instance: Multi-premises customers appreciate having all meters read on the same day so that they can more easily compare consumption at various sites. Customers in competitive regions can match their consumption profile (detailed via Smart Grid data) with specific offerings from competitive suppliers. Customers seeing inexplicable consumption patterns and power quality problems may investigate further. The result can be discovery of electrical problems that can be resolved through rewiring or maintenance—before more serious fires or accidents happen. Smart Grid Business Software Facilitates Use of Renewables Generation from wind and solar resources is a popular alternative to fossil fuel generation, which emits greenhouse gases. Wind and solar generation may also increase energy security in regions that currently import fossil fuel for use in generation. Utilities face many technical issues as they attempt to integrate intermittent resource generation into traditional grids, which traditionally handle only fully dispatchable generation. Smart Grid business software helps solves many of these issues by: Detecting sudden drops in production from renewables-generated electricity (wind and solar) and automatically triggering electricity storage and smart appliance response to compensate as needed. Supporting industry-standard distributed generation interconnection processes to reduce interconnection costs and avoid adding renewable supplies to locations already subject to grid congestion. Facilitating modeling and monitoring of locally generated supply from renewables and thus helping to maximize their use. Increasing the efficiency of “net metering” (through which utilities can use electricity generated by customers) by: Providing data for analysis. Integrating the production and consumption aspects of customer accounts. During non-peak periods, such techniques enable utilities to increase the percent of renewable generation in their supply mix. During peak periods, Smart Grid business software controls circuit reconfiguration to maximize available capacity. Conclusion Utility missions are changing. Yesterday, they focused on delivery of reasonably priced energy and water. Tomorrow, their missions will expand to encompass sustainable use and environmental improvement.Smart Grids are key to helping utilities achieve this expanded mission. But they come at a relatively high price. Utilities will need to invest heavily in new hardware, software, business process development, and staff training. Customer investments in home area networks and smart appliances will be large. Learning to change the energy and water consumption habits of a lifetime could ultimately prove even more formidable tasks.Smart Grid business software can ease the cost and difficulties inherent in a needed transition to a more flexible, reliable, responsive electricity grid. Justifying its implementation, however, requires a full understanding of the benefits it brings—benefits that can ultimately help customers, utilities, communities, and the world address global issues like energy security and climate change while minimizing costs and maximizing customer convenience. This white paper is available for download here. For further information about Oracle's Primavera Solutions for Utilities, please read our Utilities e-book.

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• Nagging As A Strategy For Better Linking: -z guidance

  - by user9154181

  The link-editor (ld) in Solaris 11 has a new feature that we call guidance that is intended to help you build better objects. The basic idea behind guidance is that if (and only if) you request it, the link-editor will issue messages suggesting better options and other changes you might make to your ld command to get better results. You can choose to take the advice, or you can disable specific types of guidance while acting on others. In some ways, this works like an experienced friend leaning over your shoulder and giving you advice — you're free to take it or leave it as you see fit, but you get nudged to do a better job than you might have otherwise. We use guidance to build the core Solaris OS, and it has proven to be useful, both in improving our objects, and in making sure that regressions don't creep back in later. In this article, I'm going to describe the evolution in thinking and design that led to the implementation of the -z guidance option, as well as give a brief description of how it works. The guidance feature issues non-fatal warnings. However, experience shows that once developers get used to ignoring warnings, it is inevitable that real problems will be lost in the noise and ignored or missed. This is why we have a zero tolerance policy against build noise in the core Solaris OS. In order to get maximum benefit from -z guidance while maintaining this policy, I added the -z fatal-warnings option at the same time. Much of the material presented here is adapted from the arc case: PSARC 2010/312 Link-editor guidance The History Of Unfortunate Link-Editor Defaults The Solaris link-editor is one of the oldest Unix commands. It stands to reason that this would be true — in order to write an operating system, you need the ability to compile and link code. The original link-editor (ld) had defaults that made sense at the time. As new features were needed, command line option switches were added to let the user use them, while maintaining backward compatibility for those who didn't. Backward compatibility is always a concern in system design, but is particularly important in the case of the tool chain (compilers, linker, and related tools), since it is a basic building block for the entire system. Over the years, applications have grown in size and complexity. Important concepts like dynamic linking that didn't exist in the original Unix system were invented. Object file formats changed. In the case of System V Release 4 Unix derivatives like Solaris, the ELF (Extensible Linking Format) was adopted. Since then, the ELF system has evolved to provide tools needed to manage today's larger and more complex environments. Features such as lazy loading, and direct bindings have been added. In an ideal world, many of these options would be defaults, with rarely used options that allow the user to turn them off. However, the reality is exactly the reverse: For backward compatibility, these features are all options that must be explicitly turned on by the user. This has led to a situation in which most applications do not take advantage of the many improvements that have been made in linking over the last 20 years. If their code seems to link and run without issue, what motivation does a developer have to read a complex manpage, absorb the information provided, choose the features that matter for their application, and apply them? Experience shows that only the most motivated and diligent programmers will make that effort. We know that most programs would be improved if we could just get you to use the various whizzy features that we provide, but the defaults conspire against us. We have long wanted to do something to make it easier for our users to use the linkers more effectively. There have been many conversations over the years regarding this issue, and how to address it. They always break down along the following lines: Change ld Defaults Since the world would be a better place the newer ld features were the defaults, why not change things to make it so? This idea is simple, elegant, and impossible. Doing so would break a large number of existing applications, including those of ISVs, big customers, and a plethora of existing open source packages. In each case, the owner of that code may choose to follow our lead and fix their code, or they may view it as an invitation to reconsider their commitment to our platform. Backward compatibility, and our installed base of working software, is one of our greatest assets, and not something to be lightly put at risk. Breaking backward compatibility at this level of the system is likely to do more harm than good. But, it sure is tempting. New Link-Editor One might create a new linker command, not called 'ld', leaving the old command as it is. The new one could use the same code as ld, but would offer only modern options, with the proper defaults for features such as direct binding. The resulting link-editor would be a pleasure to use. However, the approach is doomed to niche status. There is a vast pile of exiting code in the world built around the existing ld command, that reaches back to the 1970's. ld use is embedded in large and unknown numbers of makefiles, and is used by name by compilers that execute it. A Unix link-editor that is not named ld will not find a majority audience no matter how good it might be. Finally, a new linker command will eventually cease to be new, and will accumulate its own burden of backward compatibility issues. An Option To Make ld Do The Right Things Automatically This line of reasoning is best summarized by a CR filed in 2005, entitled 6239804 make it easier for ld(1) to do what's best The idea is to have a '-z best' option that unchains ld from its backward compatibility commitment, and allows it to turn on the "best" set of features, as determined by the authors of ld. The specific set of features enabled by -z best would be subject to change over time, as requirements change. This idea is more realistic than the other two, but was never implemented because it has some important issues that we could never answer to our satisfaction: The -z best proposal assumes that the user can turn it on, and trust it to select good options without the user needing to be aware of the options being applied. This is a fallacy. Features such as direct bindings require the user to do some analysis to ensure that the resulting program will still operate properly. A user who is willing to do the work to verify that what -z best does will be OK for their application is capable of turning on those features directly, and therefore gains little added benefit from -z best. The intent is that when a user opts into -z best, that they understand that z best is subject to sometimes incompatible evolution. Experience teaches us that this won't work. People will use this feature, the meaning of -z best will change, code that used to build will fail, and then there will be complaints and demands to retract the change. When (not if) this occurs, we will of course defend our actions, and point at the disclaimer. We'll win some of those debates, and lose others. Ultimately, we'll end up with -z best2 (-z better), or other compromises, and our goal of simplifying the world will have failed. The -z best idea rolls up a set of features that may or may not be related to each other into a unit that must be taken wholesale, or not at all. It could be that only a subset of what it does is compatible with a given application, in which case the user is expected to abandon -z best and instead set the options that apply to their application directly. In doing so, they lose one of the benefits of -z best, that if you use it, future versions of ld may choose a different set of options, and automatically improve the object through the act of rebuilding it. I drew two conclusions from the above history: For a link-editor, backward compatibility is vital. If a given command line linked your application 10 years ago, you have every reason to expect that it will link today, assuming that the libraries you're linking against are still available and compatible with their previous interfaces. For an application of any size or complexity, there is no substitute for the work involved in examining the code and determining which linker options apply and which do not. These options are largely orthogonal to each other, and it can be reasonable not to use any or all of them, depending on the situation, even in modern applications. It is a mistake to tie them together. The idea for -z guidance came from consideration of these points. By decoupling the advice from the act of taking the advice, we can retain the good aspects of -z best while avoiding its pitfalls: -z guidance gives advice, but the decision to take that advice remains with the user who must evaluate its merit and make a decision to take it or not. As such, we are free to change the specific guidance given in future releases of ld, without breaking existing applications. The only fallout from this will be some new warnings in the build output, which can be ignored or dealt with at the user's convenience. It does not couple the various features given into a single "take it or leave it" option, meaning that there will never be a need to offer "-zguidance2", or other such variants as things change over time. Guidance has the potential to be our final word on this subject. The user is given the flexibility to disable specific categories of guidance without losing the benefit of others, including those that might be added to future versions of the system. Although -z fatal-warnings stands on its own as a useful feature, it is of particular interest in combination with -z guidance. Used together, the guidance turns from advice to hard requirement: The user must either make the suggested change, or explicitly reject the advice by specifying a guidance exception token, in order to get a build. This is valuable in environments with high coding standards. ld Command Line Options The guidance effort resulted in new link-editor options for guidance and for turning warnings into fatal errors. Before I reproduce that text here, I'd like to highlight the strategic decisions embedded in the guidance feature: In order to get guidance, you have to opt in. We hope you will opt in, and believe you'll get better objects if you do, but our default mode of operation will continue as it always has, with full backward compatibility, and without judgement. Guidance suggestions always offers specific advice, and not vague generalizations. You can disable some guidance without turning off the entire feature. When you get guidance warnings, you can choose to take the advice, or you can specify a keyword to disable guidance for just that category. This allows you to get guidance for things that are useful to you, without being bothered about things that you've already considered and dismissed. As the world changes, we will add new guidance to steer you in the right direction. All such new guidance will come with a keyword that let's you turn it off. In order to facilitate building your code on different versions of Solaris, we quietly ignore any guidance keywords we don't recognize, assuming that they are intended for newer versions of the link-editor. If you want to see what guidance tokens ld does and does not recognize on your system, you can use the ld debugging feature as follows: % ld -Dargs -z guidance=foo,nodefs debug: debug: Solaris Linkers: 5.11-1.2275 debug: debug: arg[1] option=-D: option-argument: args debug: arg[2] option=-z: option-argument: guidance=foo,nodefs debug: warning: unrecognized -z guidance item: foo The -z fatal-warning option is straightforward, and generally useful in environments with strict coding standards. Note that the GNU ld already had this feature, and we accept their option names as synonyms: -z fatal-warnings | nofatal-warnings --fatal-warnings | --no-fatal-warnings The -z fatal-warnings and the --fatal-warnings option cause the link-editor to treat warnings as fatal errors. The -z nofatal-warnings and the --no-fatal-warnings option cause the link-editor to treat warnings as non-fatal. This is the default behavior. The -z guidance option is defined as follows: -z guidance[=item1,item2,...] Provide guidance messages to suggest ld options that can improve the quality of the resulting object, or which are otherwise considered to be beneficial. The specific guidance offered is subject to change over time as the system evolves. Obsolete guidance offered by older versions of ld may be dropped in new versions. Similarly, new guidance may be added to new versions of ld. Guidance therefore always represents current best practices. It is possible to enable guidance, while preventing specific guidance messages, by providing a list of item tokens, representing the class of guidance to be suppressed. In this way, unwanted advice can be suppressed without losing the benefit of other guidance. Unrecognized item tokens are quietly ignored by ld, allowing a given ld command line to be executed on a variety of older or newer versions of Solaris. The guidance offered by the current version of ld, and the item tokens used to disable these messages, are as follows. Specify Required Dependencies Dynamic executables and shared objects should explicitly define all of the dependencies they require. Guidance recommends the use of the -z defs option, should any symbol references remain unsatisfied when building dynamic objects. This guidance can be disabled with -z guidance=nodefs. Do Not Specify Non-Required Dependencies Dynamic executables and shared objects should not define any dependencies that do not satisfy the symbol references made by the dynamic object. Guidance recommends that unused dependencies be removed. This guidance can be disabled with -z guidance=nounused. Lazy Loading Dependencies should be identified for lazy loading. Guidance recommends the use of the -z lazyload option should any dependency be processed before either a -z lazyload or -z nolazyload option is encountered. This guidance can be disabled with -z guidance=nolazyload. Direct Bindings Dependencies should be referenced with direct bindings. Guidance recommends the use of the -B direct, or -z direct options should any dependency be processed before either of these options, or the -z nodirect option is encountered. This guidance can be disabled with -z guidance=nodirect. Pure Text Segment Dynamic objects should not contain relocations to non-writable, allocable sections. Guidance recommends compiling objects with Position Independent Code (PIC) should any relocations against the text segment remain, and neither the -z textwarn or -z textoff options are encountered. This guidance can be disabled with -z guidance=notext. Mapfile Syntax All mapfiles should use the version 2 mapfile syntax. Guidance recommends the use of the version 2 syntax should any mapfiles be encountered that use the version 1 syntax. This guidance can be disabled with -z guidance=nomapfile. Library Search Path Inappropriate dependencies that are encountered by ld are quietly ignored. For example, a 32-bit dependency that is encountered when generating a 64-bit object is ignored. These dependencies can result from incorrect search path settings, such as supplying an incorrect -L option. Although benign, this dependency processing is wasteful, and might hide a build problem that should be solved. Guidance recommends the removal of any inappropriate dependencies. This guidance can be disabled with -z guidance=nolibpath. In addition, -z guidance=noall can be used to entirely disable the guidance feature. See Chapter 7, Link-Editor Quick Reference, in the Linker and Libraries Guide for more information on guidance and advice for building better objects. Example The following example demonstrates how the guidance feature is intended to work. We will build a shared object that has a variety of shortcomings: Does not specify all it's dependencies Specifies dependencies it does not use Does not use direct bindings Uses a version 1 mapfile Contains relocations to the readonly allocable text (not PIC) This scenario is sadly very common — many shared objects have one or more of these issues. % cat hello.c #include <stdio.h> #include <unistd.h> void hello(void) { printf("hello user %d\n", getpid()); } % cat mapfile.v1 # This version 1 mapfile will trigger a guidance message % cc hello.c -o hello.so -G -M mapfile.v1 -lelf As you can see, the operation completes without error, resulting in a usable object. However, turning on guidance reveals a number of things that could be better: % cc hello.c -o hello.so -G -M mapfile.v1 -lelf -zguidance ld: guidance: version 2 mapfile syntax recommended: mapfile.v1 ld: guidance: -z lazyload option recommended before first dependency ld: guidance: -B direct or -z direct option recommended before first dependency Undefined first referenced symbol in file getpid hello.o (symbol belongs to implicit dependency /lib/libc.so.1) printf hello.o (symbol belongs to implicit dependency /lib/libc.so.1) ld: warning: symbol referencing errors ld: guidance: -z defs option recommended for shared objects ld: guidance: removal of unused dependency recommended: libelf.so.1 warning: Text relocation remains referenced against symbol offset in file .rodata1 (section) 0xa hello.o getpid 0x4 hello.o printf 0xf hello.o ld: guidance: position independent (PIC) code recommended for shared objects ld: guidance: see ld(1) -z guidance for more information Given the explicit advice in the above guidance messages, it is relatively easy to modify the example to do the right things: % cat mapfile.v2 # This version 2 mapfile will not trigger a guidance message $mapfile_version 2 % cc hello.c -o hello.so -Kpic -G -Bdirect -M mapfile.v2 -lc -zguidance There are situations in which the guidance does not fit the object being built. For instance, you want to build an object without direct bindings: % cc -Kpic hello.c -o hello.so -G -M mapfile.v2 -lc -zguidance ld: guidance: -B direct or -z direct option recommended before first dependency ld: guidance: see ld(1) -z guidance for more information It is easy to disable that specific guidance warning without losing the overall benefit from allowing the remainder of the guidance feature to operate: % cc -Kpic hello.c -o hello.so -G -M mapfile.v2 -lc -zguidance=nodirect Conclusions The linking guidelines enforced by the ld guidance feature correspond rather directly to our standards for building the core Solaris OS. I'm sure that comes as no surprise. It only makes sense that we would want to build our own product as well as we know how. Solaris is usually the first significant test for any new linker feature. We now enable guidance by default for all builds, and the effect has been very positive. Guidance helps us find suboptimal objects more quickly. Programmers get concrete advice for what to change instead of vague generalities. Even in the cases where we override the guidance, the makefile rules to do so serve as documentation of the fact. Deciding to use guidance is likely to cause some up front work for most code, as it forces you to consider using new features such as direct bindings. Such investigation is worthwhile, but does not come for free. However, the guidance suggestions offer a structured and straightforward way to tackle modernizing your objects, and once that work is done, for keeping them that way. The investment is often worth it, and will replay you in terms of better performance and fewer problems. I hope that you find guidance to be as useful as we have.

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• HELP!! Delayed-job: Rake aborted! Can't modify frozen hash

  - by pmneve

  Too bad even the trace doesn't say which hash is involved. Sorry this post is long: am trying to provide enough context to be meaningful. Occurs intermittently when rake jobs:work is pulling a command out of delayed_jobs while my status observer is in the process of parsing a log file for detailed results of the previous delayed_job denizen. I have an observer class (in RAILS_ROOT/lib ) which listens for the events, makes a copy of them and calls the owner class ( in apps/models ) which then calls on the log parser (also in /lib) to do the actual work. (Should both of those classes, the observer and the parser be in app/models?) Am due to deliver this application in a few days and this is killing it (and me). Am using DirectoryWatcher to look for flag files that indicate the start and finish of the delayed_jobs. That is started at the end of environment.rb like this: require 'directory_watcher' $scriptStatusObserver = ScriptStatusObserver.new dirToWatch ="#{RAILS_ROOT}/tmp/flags" $directoryWatcher = DirectoryWatcher.new( dirToWatch ) $directoryWatcher.glob= "*.flg" $directoryWatcher.interval=(15) $directoryWatcher.add_observer( $scriptStatusObserver ) $directoryWatcher.persist=("#{RAILS_ROOT}/tmp/flags/dw_state.yml") $directoryWatcher.start at_exit { $directoryWatcher.stop } This code is outside of the run method (btw is that the best place or is inside the run better?) Here is the observer: require 'script_run' class ScriptStatusObserver def initialize @rcvdEvents = [] end def update( *events ) begin puts "#{LINE.to_s}: ScriptStatusObserver events: \n"+events.to_yaml cnt = 0 events.each do |e| if e.to_s.match(/^\s*added/) cnt = cnt + 1 @rcvdEvents << e end end ScriptRun.new.catch_up( @rcvdEvents ) if cnt > 0 @rcvdEvents.clear rescue puts $! end end end Here is ScriptRun (it attaches to an associative table built with has_many:through) require 'observer' class ScriptRun < ActiveRecord::Base set_table_name "scripts_runs" belongs_to :script belongs_to :run def parse( result ) parser = LogParser.new parser.parse(result) end def catch_up( events ) events.each do |e| typ = e.type path = e.path thisMatch = path.match(/flags\/(\d+)_(\d+)_([\d\.]+)_(\w+)\.flg/) run_id = thisMatch[1] script_id = thisMatch[2] ts = thisMatch[3] status = thisMatch[4] if e.to_s.match(/^\s*added/) status_update( script_id, run_id, status, ts, path ) end end end def status_update( script_id, run_id, status, ts, path ) scriptrun = ScriptRun.find(:first, :conditions => [ "run_id = ? and script_id = ?", run_id.to_i, script_id.to_i ]) if scriptrun.kind_of?(ScriptRun) currStatus = scriptrun.status if not currStatus == 'completed' scriptrun.update_attribute(:status, status) if status == 'parse' flag = File.new(path) logSpec = flag.gets flag.close logName = File.basename(logSpec) logPath = logSpec.sub(logName, '') logName =~ /^(([\w_]+)_([\w]+)_(\d+))\.log$/ name = $1 basename = $2 runenv = $3 tsOrPid = $4 result = Result.new result.log_path = logPath result.basename = basename result.name = name result.script_id = script_id.to_i result.run_id = run_id.to_i if runenv == 'sit' runenv = 'SIT3348' end result.application_environment_id = ApplicationEnvironment.find(:first, :conditions => [ "nodename = ?", runenv]).id parse(result) if run_completed?( run_id ) myRun = Run.find(run_id.to_i) if myRun.kind_of?( Run ) myRun.update_attribute( :completed, Time.now.to_f ) end end end end else puts "#{__LINE__.to_s}: ScriptRun.status_update: ScriptRun not found for run #{run_id} script #{script_id} ts #{ts.to_s}" end File.delete(path) end def run_completed?( id ) scriptruns = ScriptRun.find(:all, :conditions = [ "run_id = ?", id.to_i] ) scriptruns.each do |sr| if not sr.status == 'completed' return false end end return true end end LogParser is too long even for this post but it reads the script log and pulls detailed information (counts and timings) out of the log and writes to a details table. It also tallies and calculates averages and rolls those up into summary tables for quicker access from the web pages. Here is the error trace: (don't ask why everything is under my Windows profile. It's a long story) Scanner running 1270239731.43 directory_watcher.notify_observers: #, #] update:[#, /pneve/workspace/waftt-0.29/tmp/flags/100039_18_1270239550.108_parse.flg"] rake aborted! can't modify frozen hash C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activerecord/l ib/active_record/attribute_methods.rb:313:in []=' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activerecord/l ib/active_record/attribute_methods.rb:313:inwrite_attribute_without_dirty' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activerecord/l ib/active_record/dirty.rb:139:in write_attribute' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activerecord/l ib/active_record/attribute_methods.rb:211:inlast_error=' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:141:in handle_failed_job' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:115:inrun' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:162:in reserve_and_run_one_job' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:92:inwork_off' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:91:in times' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:91:inwork_off' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:66:in start' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activesupport/ lib/active_support/core_ext/benchmark.rb:10:inrealtime' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:65:in start' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:62:inloop' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:62:in start' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/tasks.rb:13 c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:636:incall' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:636:in execute' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:631:ineach' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:631:in execute' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:597:ininvoke_with_call_chain' c:/Documents and Settings/pneve/ruby/lib/ruby/1.8/monitor.rb:242:in synchronize ' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:590:ininvoke_with_call_chain' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:583:in invoke' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2051:ininvoke_task' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2029:in top_level' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2029:ineach' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2029:in top_level' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2068:instandard_exception_handling' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2023:in top_level' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2001:inrun' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2068:in standard_exception_handling' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:1998:inrun' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/bin/rake: 31 c:/Documents and Settings/pneve/ruby/bin/rake:16:in `load' c:/Documents and Settings/pneve/ruby/bin/rake:16

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• HELP!! Rake aborted! Can't modify frozen hash

  - by pmneve

  Too bad even the trace doesn't say which hash is involved. Sorry this post is long: am trying to provide enough context to be meaningful. Occurs intermittently when rake jobs:work is pulling a command out of delayed_jobs while my status observer is in the process of parsing a log file for detailed results of the previous delayed_job denizen. I have an observer class (in RAILS_ROOT/lib ) which listens for the events, makes a copy of them and calls the owner class ( in apps/models ) which then calls on the log parser (also in /lib) to do the actual work. (Should both of those classes, the observer and the parser be in app/models?) Am due to deliver this application in a few days and this is killing it (and me). Am using DirectoryWatcher to look for flag files that indicate the start and finish of the delayed_jobs. That is started at the end of environment.rb like this: require 'directory_watcher' $scriptStatusObserver = ScriptStatusObserver.new dirToWatch ="#{RAILS_ROOT}/tmp/flags" $directoryWatcher = DirectoryWatcher.new( dirToWatch ) $directoryWatcher.glob= "*.flg" $directoryWatcher.interval=(15) $directoryWatcher.add_observer( $scriptStatusObserver ) $directoryWatcher.persist=("#{RAILS_ROOT}/tmp/flags/dw_state.yml") $directoryWatcher.start at_exit { $directoryWatcher.stop } This code is outside of the run method (btw is that the best place or is inside the run better?) Here is the observer: require 'script_run' class ScriptStatusObserver def initialize @rcvdEvents = [] end def update( *events ) begin puts "#{LINE.to_s}: ScriptStatusObserver events: \n"+events.to_yaml cnt = 0 events.each do |e| if e.to_s.match(/^\s*added/) cnt = cnt + 1 @rcvdEvents << e end end ScriptRun.new.catch_up( @rcvdEvents ) if cnt > 0 @rcvdEvents.clear rescue puts $! end end end Here is ScriptRun (it attaches to an associative table built with has_many:through) require 'observer' class ScriptRun < ActiveRecord::Base set_table_name "scripts_runs" belongs_to :script belongs_to :run def parse( result ) parser = LogParser.new parser.parse(result) end def catch_up( events ) events.each do |e| typ = e.type path = e.path thisMatch = path.match(/flags\/(\d+)_(\d+)_([\d\.]+)_(\w+)\.flg/) run_id = thisMatch[1] script_id = thisMatch[2] ts = thisMatch[3] status = thisMatch[4] if e.to_s.match(/^\s*added/) status_update( script_id, run_id, status, ts, path ) end end end def status_update( script_id, run_id, status, ts, path ) scriptrun = ScriptRun.find(:first, :conditions => [ "run_id = ? and script_id = ?", run_id.to_i, script_id.to_i ]) if scriptrun.kind_of?(ScriptRun) currStatus = scriptrun.status if not currStatus == 'completed' scriptrun.update_attribute(:status, status) if status == 'parse' flag = File.new(path) logSpec = flag.gets flag.close logName = File.basename(logSpec) logPath = logSpec.sub(logName, '') logName =~ /^(([\w_]+)_([\w]+)_(\d+))\.log$/ name = $1 basename = $2 runenv = $3 tsOrPid = $4 result = Result.new result.log_path = logPath result.basename = basename result.name = name result.script_id = script_id.to_i result.run_id = run_id.to_i if runenv == 'sit' runenv = 'SIT3348' end result.application_environment_id = ApplicationEnvironment.find(:first, :conditions => [ "nodename = ?", runenv]).id parse(result) if run_completed?( run_id ) myRun = Run.find(run_id.to_i) if myRun.kind_of?( Run ) myRun.update_attribute( :completed, Time.now.to_f ) end end end end else puts "#{__LINE__.to_s}: ScriptRun.status_update: ScriptRun not found for run #{run_id} script #{script_id} ts #{ts.to_s}" end File.delete(path) end def run_completed?( id ) scriptruns = ScriptRun.find(:all, :conditions = [ "run_id = ?", id.to_i] ) scriptruns.each do |sr| if not sr.status == 'completed' return false end end return true end end LogParser is too long even for this post but it reads the script log and pulls detailed information (counts and timings) out of the log and writes to a details table. It also tallies and calculates averages and rolls those up into summary tables for quicker access from the web pages. Here is the error trace: (don't ask why everything is under my Windows profile. It's a long story) Scanner running 1270239731.43 directory_watcher.notify_observers: #, #] update:[#, /pneve/workspace/waftt-0.29/tmp/flags/100039_18_1270239550.108_parse.flg"] rake aborted! can't modify frozen hash C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activerecord/l ib/active_record/attribute_methods.rb:313:in []=' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activerecord/l ib/active_record/attribute_methods.rb:313:inwrite_attribute_without_dirty' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activerecord/l ib/active_record/dirty.rb:139:in write_attribute' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activerecord/l ib/active_record/attribute_methods.rb:211:inlast_error=' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:141:in handle_failed_job' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:115:inrun' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:162:in reserve_and_run_one_job' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:92:inwork_off' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:91:in times' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:91:inwork_off' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:66:in start' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activesupport/ lib/active_support/core_ext/benchmark.rb:10:inrealtime' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:65:in start' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:62:inloop' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:62:in start' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/tasks.rb:13 c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:636:incall' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:636:in execute' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:631:ineach' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:631:in execute' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:597:ininvoke_with_call_chain' c:/Documents and Settings/pneve/ruby/lib/ruby/1.8/monitor.rb:242:in synchronize ' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:590:ininvoke_with_call_chain' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:583:in invoke' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2051:ininvoke_task' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2029:in top_level' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2029:ineach' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2029:in top_level' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2068:instandard_exception_handling' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2023:in top_level' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2001:inrun' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2068:in standard_exception_handling' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:1998:inrun' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/bin/rake: 31 c:/Documents and Settings/pneve/ruby/bin/rake:16:in `load' c:/Documents and Settings/pneve/ruby/bin/rake:16

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• What arguments do I send a function being called by a button in python?

  - by Jared

  I have a UI, in that UI is 4 text fields and 1 int field, then I have a function that calls to another function based on what's inside of the text fields, this function has (self, *args). My function that is being called to takes five arguments and I don't know what to put in it to make it actually work with my UI because python button's send an argument of their own. I have tried self and *args, but it doesn't work. Here is my code, didn't include most of the UI code since it is self explanatory: def crBC(self, IKJoint, FKJoint, bindJoint, xQuan, switch): ''' You should have a controller with an attribute 'ikFkBlend' - The name can be changed after the script executes. Controller should contain an enum - FK/DYN(0), IK(1). Specify the IK joint, then either the dynamic or FK joint, then the bind joint. Then a quantity of joints to pass through and connect. Tested currently on 600 joints (200 x 3), executed in less than a second. Returns nothing. Please open your script editor for details. ''' import itertools # gets children joints of the selected joint chHipIK = cmds.listRelatives(IKJoint, ad = True, type = 'joint') chHipFK = cmds.listRelatives(FKJoint, ad = True, type = 'joint') chHipBind = cmds.listRelatives(bindJoint, ad = True, type = 'joint') # list is built backwards, this reverses the list chHipIK.reverse() chHipFK.reverse() chHipBind.reverse() # appends the initial joint to the list chHipIK.append(IKJoint) chHipFK.append(FKJoint) chHipBind.append(bindJoint) # puts the last joint at the start of the list because the initial joint # was added to the end chHipIK.insert(0, chHipIK.pop()) chHipFK.insert(0, chHipFK.pop()) chHipBind.insert(0, chHipBind.pop()) # pops off the remaining joints in the list the user does not wish to be blended chHipBind[xQuan:] = [] chHipIK[xQuan:] = [] chHipFK[xQuan:] = [] # goes through the bind joints, makes a blend colors for each one, connects # the switch to the blender for a, b, c in itertools.izip(chHipBind, chHipIK, chHipFK): rotBC = cmds.shadingNode('blendColors', asUtility = True, n = a + 'rotate_BC') tranBC = cmds.shadingNode('blendColors', asUtility = True, n = a + 'tran_BC') scaleBC = cmds.shadingNode('blendColors', asUtility = True, n = a + 'scale_BC') cmds.connectAttr(switch + '.ikFkSwitch', rotBC + '.blender') cmds.connectAttr(switch + '.ikFkSwitch', tranBC + '.blender') cmds.connectAttr(switch + '.ikFkSwitch', scaleBC + '.blender') # goes through the ik joints, connects to the blend colors cmds.connectAttr(b + '.rotate', rotBC + '.color1', force = True) cmds.connectAttr(b + '.translate', tranBC + '.color1', force = True) cmds.connectAttr(b + '.scale', scaleBC + '.color1', force = True) # connects FK joints to the blend colors cmds.connectAttr(c + '.rotate', rotBC + '.color2') cmds.connectAttr(c + '.translate', tranBC + '.color2') cmds.connectAttr(c + '.scale', scaleBC + '.color2') # connects blend colors to bind joints cmds.connectAttr(rotBC + '.output', a + '.rotate') cmds.connectAttr(tranBC + '.output', a + '.translate') cmds.connectAttr(scaleBC + '.output', a + '.scale') ------------------- def execCrBC(self, *args): g.crBC(cmds.textField(self.ikJBC, q = True, tx = True), cmds.textField(self.fkJBC, q = True, tx = True), cmds.textField(self.bindJBC, q = True, tx = True), cmds.intField(self.bQBC, q = True, v = True), cmds.textField(self.sCBC, q = True, tx = True)) ------------------- self.bQBC = cmds.intField() cmds.text(l = '') self.sCBC = cmds.textField() cmds.text(l = '') cmds.button(l = 'Help Docs', c = self.crBC.__doc__) cmds.setParent('..') cmds.button(l = 'Create', c = self.execCrBC) Here is the code causing the problem as requested: import maya.cmds as cmds import jtRigUI.createDummyRig as dum import jtRigUI.createSkeleton as sk import jtRigUI.generalUtilities as gu import jtRigUI.createLegRig as lr import jtRigUI.createArmRig as ar class RUI(dum.Dict, dum.Dummy, sk.Skel, sk.FiSkel, lr.LeanLocs, lr.LegRig, ar.ArmRig, gu.Gutils): def __init__(self, charNameUI, gScaleUI, fingButtonGrp, thumbCheckBox, spineButtonGrp, neckButtonGrp, ikJBC, fkJBC, bindJBC, bQBC, sCBC): rigUI = 'rigUI' if cmds.window(rigUI, exists = True): cmds.deleteUI(rigUI) rigUI = cmds.window(rigUI, t = 'JT Rigging UI', sizeable = False, tb = True, mnb = False, mxb = False, menuBar = True, tlb = True, nm = 5) form = cmds.formLayout() tabs = cmds.tabLayout(innerMarginWidth = 1, innerMarginHeight = 1) rigUIMenu = cmds.menu('Help', hm = True) aboutMenu = cmds.menuItem('about') cmds.popupMenu('about', button = 1) deleteUIMenu = cmds.menu('Delete', hm = True) cmds.menuItem('dummySkeleton') cmds.formLayout(form, edit = True, attachForm = ((tabs, 'top', 0), (tabs, 'left', 0), (tabs, 'bottom', 0), (tabs, 'right', 0)), w = 30) tab1 = cmds.rowColumnLayout('Dummy') #cmds.columnLayout(rowSpacing = 10) #cmds.setParent('..') cmds.frameLayout(l = 'A: Dummy Skeleton Setup', w = 400) self.charNameUI = cmds.textFieldGrp (label="Optional Character Name:", ann="Insert a name for the character or leave empty.", tx = '', w = 1) fingJUI = cmds.frameLayout(l = 'B: Number of Fingers', w = 10) cmds.text('\n', h = 5) self.fingButtonGrp = cmds.radioButtonGrp('fingRadio', p = fingJUI, l = 'Fingers: ', sl = 4, w = 1, numberOfRadioButtons = 4, labelArray4 = ['One', 'Two', 'Three', 'Four'], ct2 = ('left', 'left'), cw5 = [60,60,60,60,60]) self.thumbCheckBox = cmds.checkBoxGrp(l = 'Thumb: ', v1 = True) cmds.text('\n', h = 5) spineJUI = cmds.frameLayout(l = 'C: Number of Spine Joints') cmds.text('\n', h = 5) self.spineButtonGrp = cmds.radioButtonGrp('spineRadio', p = spineJUI, l = 'Spine Joints: ', sl = 2, w = 1, numberOfRadioButtons = 3, labelArray3 = ['Three', 'Five', 'Ten'], ct2 = ('left', 'left'), cw4 = [95,95,95,95]) cmds.text('\n', h = 5) neckJUI = cmds.frameLayout(l = 'D: Number of Neck Joints') cmds.text('\n', h = 5) self.neckButtonGrp = cmds.radioButtonGrp('neckRadio', p = neckJUI, l = 'Neck Joints: ', sl = 0, w = 1, numberOfRadioButtons = 3, labelArray3 = ['Two', 'Three', 'Four'], ct2 = ('left', 'left'), cw4 = [95,95,95,95]) cmds.text('\n', h = 5) cmds.setParent('..') cmds.setParent('..') cmds.setParent('..') cmds.frameLayout('E: Creation') cmds.text('SAVE FIRST: CAN NOT UNDO', bgc = (0.2,0.2,0.2)) cmds.button(l = '\nCreate Dummy Skeleton\n', c = self.build) # also have it make char name field grey cmds.text('Elbows and Knees must have bend.', bgc = (0.2,0.2,0.2)) cmds.columnLayout() cmds.setParent('..') cmds.setParent('..') cmds.setParent('..') cmds.setParent('..') tab2 = cmds.rowColumnLayout('Skeleton') cmds.columnLayout(columnAttach = ('both', 5), rowSpacing = 10, columnWidth = 150) cmds.setParent('..') cmds.frameLayout(l = 'A: Skeleton Setup') cmds.text('SAVE FIRST: CAN NOT UNDO', bgc = (0.2,0.2,0.2)) cmds.button(l = '\nConvert to Skeleton - Orient - Set LRA\n', c = self.buildSkel) self.gScaleUI = cmds.textFieldGrp (label="Scale Multiplier:", ann="Scale multipler of Character: basis for all further base controllers", tx = '1.0', w = 1, ed = False, en = False, visible = True) cmds.frameLayout('B: Manual Orientation') cmds.text('You must manually check finger, thumb, leg, foot orientation specifically.\nConfirm rest of joints.\nSpine: X aim, Y point backwards from spine, Z to the side.\nFingers: X is aim, Y points upwards, Z to the side - Spread on Y, curl on Z.\nFoot: Pivots on Y, rolls on Z, leans on X.') cmds.columnLayout() cmds.setParent('..') cmds.frameLayout('C: Finalize Creation of Skeleton') cmds.button(l = '\nFinalize Skeleton\n', c = self.finishS) cmds.setParent('..') cmds.setParent('..') cmds.setParent('..') cmds.setParent('..') tab3 = cmds.rowColumnLayout('Legs') cmds.columnLayout(columnAttach = ('both', 5), rowSpacing = 10, columnWidth = 150) cmds.setParent('..') cmds.frameLayout(l = 'A: Leg Rig Setup') cmds.button(l = '\nGenerate Foot Lean Locators\n', c = self.makeLean) cmds.text('Place on either side of the foot.\nDo not rotate: Automatic orientation in place.') cmds.frameLayout(l = 'B: Rig Legs') cmds.button(l = '\nRig Legs\n', c = self.makeLegs) cmds.setParent('..') cmds.setParent('..') cmds.setParent('..') tab4 = cmds.rowColumnLayout('Arms') cmds.columnLayout(columnAttach = ('both', 5), rowSpacing = 10, columnWidth = 150) cmds.setParent('..') cmds.frameLayout(l = 'A: Arm Rig Setup') cmds.button(l = '\nA: Rig Arms\n', c = self.makeArms) cmds.setParent('..') cmds.setParent('..') tab5 = cmds.rowColumnLayout('Spine and Head') cmds.columnLayout(columnAttach = ('both', 5), rowSpacing = 10, columnWidth = 150) cmds.setParent('..') cmds.frameLayout(l = 'Spine Rig Setup') cmds.setParent('..') cmds.setParent('..') tab6 = cmds.rowColumnLayout('Stretchy IK') cmds.columnLayout(columnAttach = ('both', 5), rowSpacing = 10, columnWidth = 150) cmds.setParent('..') cmds.frameLayout(l = 'Stretchy Setup') cmds.setParent('..') cmds.setParent('..') tab6 = cmds.rowColumnLayout('Extras') cmds.scrollLayout(saw = 600, sah = 600, cr = True) cmds.columnLayout(columnAttach = ('both', 5), rowSpacing = 10, columnWidth = 150) cmds.setParent('..') cmds.frameLayout(l = 'General Utitlities') cmds.text('\nHere are all my general utilities for various things') cmds.frameLayout(l = 'Automatic Blend Colors Creation and Connection') cmds.rowColumnLayout(nc = 5, w = 10) cmds.text('IK Joint:') cmds.text(l = '') cmds.text('FK/Dyn Joint:') cmds.text(l = '') cmds.text('Bind Joint:') self.ikJBC = cmds.textField() cmds.text(l = '') self.fkJBC = cmds.textField() cmds.text(l = '') self.bindJBC = cmds.textField() cmds.text(' \nBlend Quantity:') cmds.text(l = '') cmds.text(' \nSwitch Control:') cmds.text(l = '') cmds.text(l = '') self.bQBC = cmds.intField() cmds.text(l = '') self.sCBC = cmds.textField() cmds.text(l = '') cmds.button(l = 'Help Docs', c = self.crBC.__doc__) cmds.setParent('..') cmds.button(l = 'Create', c = self.execCrBC) cmds.text(l = '') cmds.setParent('..') cmds.frameLayout(l = 'Make Spline IK Curve Stretch And Squash') cmds.rowColumnLayout(nc = 5, w = 10) cmds.text('Curve Name:') cmds.text(l = '') cmds.text('Setup Name:') cmds.text(l = '') cmds.text('Joint Quantity:') self.ikJBC = cmds.textField() cmds.text(l = '') self.fkJBC = cmds.textField() cmds.text(l = '') self.bindJBC = cmds.textField() cmds.text(' \nSwitch Control:') cmds.text(l = '') cmds.text(' \nGlobal Control:') cmds.text(l = '') cmds.text(l = '') self.bQBC = cmds.intField() cmds.text(l = '') self.sCBC = cmds.textField() cmds.text(l = '') cmds.button(l = 'Help Docs', c = self.crBC.__doc__) cmds.setParent('..') cmds.button(l = 'Create', c = self.execCrBC) cmds.setParent('..') cmds.showWindow(rigUI) r = RUI('charNameUI', 'gScaleUI', 'fingButtonGrp', 'thumbCheckBox', 'spineButtonGrp', 'neckButtonGrp', 'ikJBC', 'fkJBC', 'bindJBC', 'bQBC', 'sCBC') # last modified at 6.20 pm 29th June 2011

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• New features of C# 4.0

  This article covers New features of C# 4.0. Article has been divided into below sections. Introduction. Dynamic Lookup. Named and Optional Arguments. Features for COM interop. Variance. Relationship with Visual Basic. Resources. Other interested readings… 22 New Features of Visual Studio 2008 for .NET Professionals 50 New Features of SQL Server 2008 IIS 7.0 New features Introduction It is now close to a year since Microsoft Visual C# 3.0 shipped as part of Visual Studio 2008. In the VS Managed Languages team we are hard at work on creating the next version of the language (with the unsurprising working title of C# 4.0), and this document is a first public description of the planned language features as we currently see them. Please be advised that all this is in early stages of production and is subject to change. Part of the reason for sharing our plans in public so early is precisely to get the kind of feedback that will cause us to improve the final product before it rolls out. Simultaneously with the publication of this whitepaper, a first public CTP (community technology preview) of Visual Studio 2010 is going out as a Virtual PC image for everyone to try. Please use it to play and experiment with the features, and let us know of any thoughts you have. We ask for your understanding and patience working with very early bits, where especially new or newly implemented features do not have the quality or stability of a final product. The aim of the CTP is not to give you a productive work environment but to give you the best possible impression of what we are working on for the next release. The CTP contains a number of walkthroughs, some of which highlight the new language features of C# 4.0. Those are excellent for getting a hands-on guided tour through the details of some common scenarios for the features. You may consider this whitepaper a companion document to these walkthroughs, complementing them with a focus on the overall language features and how they work, as opposed to the specifics of the concrete scenarios. C# 4.0 The major theme for C# 4.0 is dynamic programming. Increasingly, objects are “dynamic” in the sense that their structure and behavior is not captured by a static type, or at least not one that the compiler knows about when compiling your program. Some examples include a. objects from dynamic programming languages, such as Python or Ruby b. COM objects accessed through IDispatch c. ordinary .NET types accessed through reflection d. objects with changing structure, such as HTML DOM objects While C# remains a statically typed language, we aim to vastly improve the interaction with such objects. A secondary theme is co-evolution with Visual Basic. Going forward we will aim to maintain the individual character of each language, but at the same time important new features should be introduced in both languages at the same time. They should be differentiated more by style and feel than by feature set. The new features in C# 4.0 fall into four groups: Dynamic lookup Dynamic lookup allows you to write method, operator and indexer calls, property and field accesses, and even object invocations which bypass the C# static type checking and instead gets resolved at runtime. Named and optional parameters Parameters in C# can now be specified as optional by providing a default value for them in a member declaration. When the member is invoked, optional arguments can be omitted. Furthermore, any argument can be passed by parameter name instead of position. COM specific interop features Dynamic lookup as well as named and optional parameters both help making programming against COM less painful than today. On top of that, however, we are adding a number of other small features that further improve the interop experience. Variance It used to be that an IEnumerable<string> wasn’t an IEnumerable<object>. Now it is – C# embraces type safe “co-and contravariance” and common BCL types are updated to take advantage of that. Dynamic Lookup Dynamic lookup allows you a unified approach to invoking things dynamically. With dynamic lookup, when you have an object in your hand you do not need to worry about whether it comes from COM, IronPython, the HTML DOM or reflection; you just apply operations to it and leave it to the runtime to figure out what exactly those operations mean for that particular object. This affords you enormous flexibility, and can greatly simplify your code, but it does come with a significant drawback: Static typing is not maintained for these operations. A dynamic object is assumed at compile time to support any operation, and only at runtime will you get an error if it wasn’t so. Oftentimes this will be no loss, because the object wouldn’t have a static type anyway, in other cases it is a tradeoff between brevity and safety. In order to facilitate this tradeoff, it is a design goal of C# to allow you to opt in or opt out of dynamic behavior on every single call. The dynamic type C# 4.0 introduces a new static type called dynamic. When you have an object of type dynamic you can “do things to it” that are resolved only at runtime: dynamic d = GetDynamicObject(…); d.M(7); The C# compiler allows you to call a method with any name and any arguments on d because it is of type dynamic. At runtime the actual object that d refers to will be examined to determine what it means to “call M with an int” on it. The type dynamic can be thought of as a special version of the type object, which signals that the object can be used dynamically. It is easy to opt in or out of dynamic behavior: any object can be implicitly converted to dynamic, “suspending belief” until runtime. Conversely, there is an “assignment conversion” from dynamic to any other type, which allows implicit conversion in assignment-like constructs: dynamic d = 7; // implicit conversion int i = d; // assignment conversion Dynamic operations Not only method calls, but also field and property accesses, indexer and operator calls and even delegate invocations can be dispatched dynamically: dynamic d = GetDynamicObject(…); d.M(7); // calling methods d.f = d.P; // getting and settings fields and properties d[“one”] = d[“two”]; // getting and setting thorugh indexers int i = d + 3; // calling operators string s = d(5,7); // invoking as a delegate The role of the C# compiler here is simply to package up the necessary information about “what is being done to d”, so that the runtime can pick it up and determine what the exact meaning of it is given an actual object d. Think of it as deferring part of the compiler’s job to runtime. The result of any dynamic operation is itself of type dynamic. Runtime lookup At runtime a dynamic operation is dispatched according to the nature of its target object d: COM objects If d is a COM object, the operation is dispatched dynamically through COM IDispatch. This allows calling to COM types that don’t have a Primary Interop Assembly (PIA), and relying on COM features that don’t have a counterpart in C#, such as indexed properties and default properties. Dynamic objects If d implements the interface IDynamicObject d itself is asked to perform the operation. Thus by implementing IDynamicObject a type can completely redefine the meaning of dynamic operations. This is used intensively by dynamic languages such as IronPython and IronRuby to implement their own dynamic object models. It will also be used by APIs, e.g. by the HTML DOM to allow direct access to the object’s properties using property syntax. Plain objects Otherwise d is a standard .NET object, and the operation will be dispatched using reflection on its type and a C# “runtime binder” which implements C#’s lookup and overload resolution semantics at runtime. This is essentially a part of the C# compiler running as a runtime component to “finish the work” on dynamic operations that was deferred by the static compiler. Example Assume the following code: dynamic d1 = new Foo(); dynamic d2 = new Bar(); string s; d1.M(s, d2, 3, null); Because the receiver of the call to M is dynamic, the C# compiler does not try to resolve the meaning of the call. Instead it stashes away information for the runtime about the call. This information (often referred to as the “payload”) is essentially equivalent to: “Perform an instance method call of M with the following arguments: 1. a string 2. a dynamic 3. a literal int 3 4. a literal object null” At runtime, assume that the actual type Foo of d1 is not a COM type and does not implement IDynamicObject. In this case the C# runtime binder picks up to finish the overload resolution job based on runtime type information, proceeding as follows: 1. Reflection is used to obtain the actual runtime types of the two objects, d1 and d2, that did not have a static type (or rather had the static type dynamic). The result is Foo for d1 and Bar for d2. 2. Method lookup and overload resolution is performed on the type Foo with the call M(string,Bar,3,null) using ordinary C# semantics. 3. If the method is found it is invoked; otherwise a runtime exception is thrown. Overload resolution with dynamic arguments Even if the receiver of a method call is of a static type, overload resolution can still happen at runtime. This can happen if one or more of the arguments have the type dynamic: Foo foo = new Foo(); dynamic d = new Bar(); var result = foo.M(d); The C# runtime binder will choose between the statically known overloads of M on Foo, based on the runtime type of d, namely Bar. The result is again of type dynamic. The Dynamic Language Runtime An important component in the underlying implementation of dynamic lookup is the Dynamic Language Runtime (DLR), which is a new API in .NET 4.0. The DLR provides most of the infrastructure behind not only C# dynamic lookup but also the implementation of several dynamic programming languages on .NET, such as IronPython and IronRuby. Through this common infrastructure a high degree of interoperability is ensured, but just as importantly the DLR provides excellent caching mechanisms which serve to greatly enhance the efficiency of runtime dispatch. To the user of dynamic lookup in C#, the DLR is invisible except for the improved efficiency. However, if you want to implement your own dynamically dispatched objects, the IDynamicObject interface allows you to interoperate with the DLR and plug in your own behavior. This is a rather advanced task, which requires you to understand a good deal more about the inner workings of the DLR. For API writers, however, it can definitely be worth the trouble in order to vastly improve the usability of e.g. a library representing an inherently dynamic domain. Open issues There are a few limitations and things that might work differently than you would expect. · The DLR allows objects to be created from objects that represent classes. However, the current implementation of C# doesn’t have syntax to support this. · Dynamic lookup will not be able to find extension methods. Whether extension methods apply or not depends on the static context of the call (i.e. which using clauses occur), and this context information is not currently kept as part of the payload. · Anonymous functions (i.e. lambda expressions) cannot appear as arguments to a dynamic method call. The compiler cannot bind (i.e. “understand”) an anonymous function without knowing what type it is converted to. One consequence of these limitations is that you cannot easily use LINQ queries over dynamic objects: dynamic collection = …; var result = collection.Select(e => e + 5); If the Select method is an extension method, dynamic lookup will not find it. Even if it is an instance method, the above does not compile, because a lambda expression cannot be passed as an argument to a dynamic operation. There are no plans to address these limitations in C# 4.0. Named and Optional Arguments Named and optional parameters are really two distinct features, but are often useful together. Optional parameters allow you to omit arguments to member invocations, whereas named arguments is a way to provide an argument using the name of the corresponding parameter instead of relying on its position in the parameter list. Some APIs, most notably COM interfaces such as the Office automation APIs, are written specifically with named and optional parameters in mind. Up until now it has been very painful to call into these APIs from C#, with sometimes as many as thirty arguments having to be explicitly passed, most of which have reasonable default values and could be omitted. Even in APIs for .NET however you sometimes find yourself compelled to write many overloads of a method with different combinations of parameters, in order to provide maximum usability to the callers. Optional parameters are a useful alternative for these situations. Optional parameters A parameter is declared optional simply by providing a default value for it: public void M(int x, int y = 5, int z = 7); Here y and z are optional parameters and can be omitted in calls: M(1, 2, 3); // ordinary call of M M(1, 2); // omitting z – equivalent to M(1, 2, 7) M(1); // omitting both y and z – equivalent to M(1, 5, 7) Named and optional arguments C# 4.0 does not permit you to omit arguments between commas as in M(1,,3). This could lead to highly unreadable comma-counting code. Instead any argument can be passed by name. Thus if you want to omit only y from a call of M you can write: M(1, z: 3); // passing z by name or M(x: 1, z: 3); // passing both x and z by name or even M(z: 3, x: 1); // reversing the order of arguments All forms are equivalent, except that arguments are always evaluated in the order they appear, so in the last example the 3 is evaluated before the 1. Optional and named arguments can be used not only with methods but also with indexers and constructors. Overload resolution Named and optional arguments affect overload resolution, but the changes are relatively simple: A signature is applicable if all its parameters are either optional or have exactly one corresponding argument (by name or position) in the call which is convertible to the parameter type. Betterness rules on conversions are only applied for arguments that are explicitly given – omitted optional arguments are ignored for betterness purposes. If two signatures are equally good, one that does not omit optional parameters is preferred. M(string s, int i = 1); M(object o); M(int i, string s = “Hello”); M(int i); M(5); Given these overloads, we can see the working of the rules above. M(string,int) is not applicable because 5 doesn’t convert to string. M(int,string) is applicable because its second parameter is optional, and so, obviously are M(object) and M(int). M(int,string) and M(int) are both better than M(object) because the conversion from 5 to int is better than the conversion from 5 to object. Finally M(int) is better than M(int,string) because no optional arguments are omitted. Thus the method that gets called is M(int). Features for COM interop Dynamic lookup as well as named and optional parameters greatly improve the experience of interoperating with COM APIs such as the Office Automation APIs. In order to remove even more of the speed bumps, a couple of small COM-specific features are also added to C# 4.0. Dynamic import Many COM methods accept and return variant types, which are represented in the PIAs as object. In the vast majority of cases, a programmer calling these methods already knows the static type of a returned object from context, but explicitly has to perform a cast on the returned value to make use of that knowledge. These casts are so common that they constitute a major nuisance. In order to facilitate a smoother experience, you can now choose to import these COM APIs in such a way that variants are instead represented using the type dynamic. In other words, from your point of view, COM signatures now have occurrences of dynamic instead of object in them. This means that you can easily access members directly off a returned object, or you can assign it to a strongly typed local variable without having to cast. To illustrate, you can now say excel.Cells[1, 1].Value = "Hello"; instead of ((Excel.Range)excel.Cells[1, 1]).Value2 = "Hello"; and Excel.Range range = excel.Cells[1, 1]; instead of Excel.Range range = (Excel.Range)excel.Cells[1, 1]; Compiling without PIAs Primary Interop Assemblies are large .NET assemblies generated from COM interfaces to facilitate strongly typed interoperability. They provide great support at design time, where your experience of the interop is as good as if the types where really defined in .NET. However, at runtime these large assemblies can easily bloat your program, and also cause versioning issues because they are distributed independently of your application. The no-PIA feature allows you to continue to use PIAs at design time without having them around at runtime. Instead, the C# compiler will bake the small part of the PIA that a program actually uses directly into its assembly. At runtime the PIA does not have to be loaded. Omitting ref Because of a different programming model, many COM APIs contain a lot of reference parameters. Contrary to refs in C#, these are typically not meant to mutate a passed-in argument for the subsequent benefit of the caller, but are simply another way of passing value parameters. It therefore seems unreasonable that a C# programmer should have to create temporary variables for all such ref parameters and pass these by reference. Instead, specifically for COM methods, the C# compiler will allow you to pass arguments by value to such a method, and will automatically generate temporary variables to hold the passed-in values, subsequently discarding these when the call returns. In this way the caller sees value semantics, and will not experience any side effects, but the called method still gets a reference. Open issues A few COM interface features still are not surfaced in C#. Most notably these include indexed properties and default properties. As mentioned above these will be respected if you access COM dynamically, but statically typed C# code will still not recognize them. There are currently no plans to address these remaining speed bumps in C# 4.0. Variance An aspect of generics that often comes across as surprising is that the following is illegal: IList<string> strings = new List<string>(); IList<object> objects = strings; The second assignment is disallowed because strings does not have the same element type as objects. There is a perfectly good reason for this. If it were allowed you could write: objects[0] = 5; string s = strings[0]; Allowing an int to be inserted into a list of strings and subsequently extracted as a string. This would be a breach of type safety. However, there are certain interfaces where the above cannot occur, notably where there is no way to insert an object into the collection. Such an interface is IEnumerable<T>. If instead you say: IEnumerable<object> objects = strings; There is no way we can put the wrong kind of thing into strings through objects, because objects doesn’t have a method that takes an element in. Variance is about allowing assignments such as this in cases where it is safe. The result is that a lot of situations that were previously surprising now just work. Covariance In .NET 4.0 the IEnumerable<T> interface will be declared in the following way: public interface IEnumerable<out T> : IEnumerable { IEnumerator<T> GetEnumerator(); } public interface IEnumerator<out T> : IEnumerator { bool MoveNext(); T Current { get; } } The “out” in these declarations signifies that the T can only occur in output position in the interface – the compiler will complain otherwise. In return for this restriction, the interface becomes “covariant” in T, which means that an IEnumerable<A> is considered an IEnumerable<B> if A has a reference conversion to B. As a result, any sequence of strings is also e.g. a sequence of objects. This is useful e.g. in many LINQ methods. Using the declarations above: var result = strings.Union(objects); // succeeds with an IEnumerable<object> This would previously have been disallowed, and you would have had to to some cumbersome wrapping to get the two sequences to have the same element type. Contravariance Type parameters can also have an “in” modifier, restricting them to occur only in input positions. An example is IComparer<T>: public interface IComparer<in T> { public int Compare(T left, T right); } The somewhat baffling result is that an IComparer<object> can in fact be considered an IComparer<string>! It makes sense when you think about it: If a comparer can compare any two objects, it can certainly also compare two strings. This property is referred to as contravariance. A generic type can have both in and out modifiers on its type parameters, as is the case with the Func<…> delegate types: public delegate TResult Func<in TArg, out TResult>(TArg arg); Obviously the argument only ever comes in, and the result only ever comes out. Therefore a Func<object,string> can in fact be used as a Func<string,object>. Limitations Variant type parameters can only be declared on interfaces and delegate types, due to a restriction in the CLR. Variance only applies when there is a reference conversion between the type arguments. For instance, an IEnumerable<int> is not an IEnumerable<object> because the conversion from int to object is a boxing conversion, not a reference conversion. Also please note that the CTP does not contain the new versions of the .NET types mentioned above. In order to experiment with variance you have to declare your own variant interfaces and delegate types. COM Example Here is a larger Office automation example that shows many of the new C# features in action. using System; using System.Diagnostics; using System.Linq; using Excel = Microsoft.Office.Interop.Excel; using Word = Microsoft.Office.Interop.Word; class Program { static void Main(string[] args) { var excel = new Excel.Application(); excel.Visible = true; excel.Workbooks.Add(); // optional arguments omitted excel.Cells[1, 1].Value = "Process Name"; // no casts; Value dynamically excel.Cells[1, 2].Value = "Memory Usage"; // accessed var processes = Process.GetProcesses() .OrderByDescending(p =&gt; p.WorkingSet) .Take(10); int i = 2; foreach (var p in processes) { excel.Cells[i, 1].Value = p.ProcessName; // no casts excel.Cells[i, 2].Value = p.WorkingSet; // no casts i++; } Excel.Range range = excel.Cells[1, 1]; // no casts Excel.Chart chart = excel.ActiveWorkbook.Charts. Add(After: excel.ActiveSheet); // named and optional arguments chart.ChartWizard( Source: range.CurrentRegion, Title: "Memory Usage in " + Environment.MachineName); //named+optional chart.ChartStyle = 45; chart.CopyPicture(Excel.XlPictureAppearance.xlScreen, Excel.XlCopyPictureFormat.xlBitmap, Excel.XlPictureAppearance.xlScreen); var word = new Word.Application(); word.Visible = true; word.Documents.Add(); // optional arguments word.Selection.Paste(); } } The code is much more terse and readable than the C# 3.0 counterpart. Note especially how the Value property is accessed dynamically. This is actually an indexed property, i.e. a property that takes an argument; something which C# does not understand. However the argument is optional. Since the access is dynamic, it goes through the runtime COM binder which knows to substitute the default value and call the indexed property. Thus, dynamic COM allows you to avoid accesses to the puzzling Value2 property of Excel ranges. Relationship with Visual Basic A number of the features introduced to C# 4.0 already exist or will be introduced in some form or other in Visual Basic: · Late binding in VB is similar in many ways to dynamic lookup in C#, and can be expected to make more use of the DLR in the future, leading to further parity with C#. · Named and optional arguments have been part of Visual Basic for a long time, and the C# version of the feature is explicitly engineered with maximal VB interoperability in mind. · NoPIA and variance are both being introduced to VB and C# at the same time. VB in turn is adding a number of features that have hitherto been a mainstay of C#. As a result future versions of C# and VB will have much better feature parity, for the benefit of everyone. Resources All available resources concerning C# 4.0 can be accessed through the C# Dev Center. Specifically, this white paper and other resources can be found at the Code Gallery site. Enjoy! span.fullpost {display:none;}

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