Search Results

Search found 23208 results on 929 pages for 'event loop'.

Page 207/929 | < Previous Page | 203 204 205 206 207 208 209 210 211 212 213 214  | Next Page >

• Capturing Ctrl-Alt-Del in JavaScript/jQuery

  - by AJ

  While just playing with jQuery/JavaScript I ran across this problem. I could capture Alt and Ctrl keys but NOT Del and certainly not all of them together. $(document).ready(function() { $("#target").keydown(function(event) { if (event.ctrlKey && event.altKey && event.keyCode == '46') { alter("Ctrl-Alt-Del combination"); } }); }); Is it possible to capture all these three keys together?

  Read the article

• Complex SQL query with group by and two rows in one

  - by Ricket

  Okay, I need help. I'm usually pretty good at SQL queries but this one baffles me. By the way, this is not a homework assignment, it's a real situation in an Access database and I've written the requirements below myself. Here is my table layout. It's in Access 2007 if that matters; I'm writing the query using SQL. Id (primary key) PersonID (foreign key) EventDate NumberOfCredits SuperCredits (boolean) There are events that people go to. They can earn normal credits, or super credits, or both at one event. The SuperCredits column is true if the row represents a number of super credits earned at the event, or false if it represents normal credits. So for example, if there is an event which person 174 attends, and they earn 3 normal credits and 1 super credit at the event, the following two rows would be added to the table: ID PersonID EventDate NumberOfCredits SuperCredits 1 174 1/1/2010 3 false 2 174 1/1/2010 1 true It is also possible that the person could have done two separate things at the event, so there might be more than two columns for one event, and it might look like this: ID PersonID EventDate NumberOfCredits SuperCredits 1 174 1/1/2010 1 false 2 174 1/1/2010 2 false 3 174 1/1/2010 1 true Now we want to print out a report. Here will be the columns of the report: PersonID LastEventDate NumberOfNormalCredits NumberOfSuperCredits The report will have one row per person. The row will show the latest event that the person attended, and the normal and super credits that the person earned at that event. What I am asking of you is to write, or help me write, the SQL query to SELECT the data and GROUP BY and SUM() and whatnot. Or, let me know if this is for some reason not possible, and how to organize my data to make it possible. This is extremely confusing and I understand if you do not take the time to puzzle through it. I've tried to simplify it as much as possible, but definitely ask any questions if you give it a shot and need clarification. I'll be trying to figure it out but I'm having a real hard time with it, this is grouping beyond my experience...

  Read the article

• Should I define models that will be owned by many different models or use controller and views?

  - by jgervin

  I am struggling to figure out how to get a relationship between several models. I have sales_leads which I need to view by company and by event. So if someone looks up the leads by company they can see all leads across all events, but also see all leads by event. Not sure if this is ownership versus a where? Should it be something like Company.sales_leads where("event.event_id = ?", "2356") Or Models: sales_lead belongs_to event belongs_to company

  Read the article

• Two Phase Commit with MongoDB

  - by mattcodes

  Heres what Im thinking. Do you see any issues with this workaround to emulate 2 phase commit when using something like MongoDB where each operation is atomic and there is no support for transactions outside of that? transaction_scope: read message from servicebus - UpdateCustomerAddress get customer aggregate from docdb, replay events where commited =1 call customer.updateAddress validates creates customer address updated event apply event event store as uncommitted events do optimistic concurrency update against docdb pushing uncommitted events (single op to ensure consistency) publish event to service bus update docdb set events just published to commited = 1 (again one 1 op - at least in mongodb) transaction_complete

  Read the article

• What database field should this be?

  - by alex

  I have a table called "Event". A column has "duration"--which is...how long that event lasts. What database type should this be? Integer? (in seconds)? In the future, I will do statements such as: If now() > event.duration THEN don't display the event.

  Read the article

• Precise explanation of JavaScript <-> DOM circular reference issue

  - by Joey Adams

  One of the touted advantages of jQuery.data versus raw expando properties (arbitrary attributes you can assign to DOM nodes) is that jQuery.data is "safe from circular references and therefore free from memory leaks". An article from Google titled "Optimizing JavaScript code" goes into more detail: The most common memory leaks for web applications involve circular references between the JavaScript script engine and the browsers' C++ objects' implementing the DOM (e.g. between the JavaScript script engine and Internet Explorer's COM infrastructure, or between the JavaScript engine and Firefox XPCOM infrastructure). It lists two examples of circular reference patterns: DOM element → event handler → closure scope → DOM DOM element → via expando → intermediary object → DOM element However, if a reference cycle between a DOM node and a JavaScript object produces a memory leak, doesn't this mean that any non-trivial event handler (e.g. onclick) will produce such a leak? I don't see how it's even possible for an event handler to avoid a reference cycle, because the way I see it: The DOM element references the event handler. The event handler references the DOM (either directly or indirectly). In any case, it's almost impossible to avoid referencing window in any interesting event handler, short of writing a setInterval loop that reads actions from a global queue. Can someone provide a precise explanation of the JavaScript ↔ DOM circular reference problem? Things I'd like clarified: What browsers are effected? A comment in the jQuery source specifically mentions IE6-7, but the Google article suggests Firefox is also affected. Are expando properties and event handlers somehow different concerning memory leaks? Or are both of these code snippets susceptible to the same kind of memory leak? // Create an expando that references to its own element. var elem = document.getElementById('foo'); elem.myself = elem; // Create an event handler that references its own element. var elem = document.getElementById('foo'); elem.onclick = function() { elem.style.display = 'none'; }; If a page leaks memory due to a circular reference, does the leak persist until the entire browser application is closed, or is the memory freed when the window/tab is closed?

  Read the article

• Microformat combination to use with events data on a map

  - by Dave Taylor

  I have event data displaying on a map and I am currently using the geo microformat alongside it however it's not particularly rich to have just a list of locations without any details of what they correspond to. I've been looking at combining microformats to achieve this and looking for some thoughts on the subject here is the data i am marking up: event title, event location [latlong], event address, contact phone, link to full details My initial thoughts are to use an hCard along with geo? Is there anything better? Thanks in advance

  Read the article

• How does Sentry aggregate errors?

  - by Hugo Rodger-Brown

  I am using Sentry (in a django project), and I'd like to know how I can get the errors to aggregate properly. I am logging certain user actions as errors, so there is no underlying system exception, and am using the culprit attribute to set a friendly error name. The message is templated, and contains a common message ("User 'x' was unable to perform action because 'y'"), but is never exactly the same (different users, different conditions). Sentry clearly uses some set of attributes under the hood to determine whether to aggregate errors as the same exception, but despite having looked through the code, I can't work out how. Can anyone short-cut my having to dig further into the code and tell me what properties I need to set in order to manage aggregation as I would like? [UPDATE 1: event grouping] This line appears in sentry.models.Group: class Group(MessageBase): """ Aggregated message which summarizes a set of Events. """ ... class Meta: unique_together = (('project', 'logger', 'culprit', 'checksum'),) ... Which makes sense - project, logger and culprit I am setting at the moment - the problem is checksum. I will investigate further, however 'checksum' suggests that binary equivalence, which is never going to work - it must be possible to group instances of the same exception, with differenct attributes? [UPDATE 2: event checksums] The event checksum comes from the sentry.manager.get_checksum_from_event method: def get_checksum_from_event(event): for interface in event.interfaces.itervalues(): result = interface.get_hash() if result: hash = hashlib.md5() for r in result: hash.update(to_string(r)) return hash.hexdigest() return hashlib.md5(to_string(event.message)).hexdigest() Next stop - where do the event interfaces come from? [UPDATE 3: event interfaces] I have worked out that interfaces refer to the standard mechanism for describing data passed into sentry events, and that I am using the standard sentry.interfaces.Message and sentry.interfaces.User interfaces. Both of these will contain different data depending on the exception instance - and so a checksum will never match. Is there any way that I can exclude these from the checksum calculation? (Or at least the User interface value, as that has to be different - the Message interface value I could standardise.) [UPDATE 4: solution] Here are the two get_hash functions for the Message and User interfaces respectively: # sentry.interfaces.Message def get_hash(self): return [self.message] # sentry.interfaces.User def get_hash(self): return [] Looking at these two, only the Message.get_hash interface will return a value that is picked up by the get_checksum_for_event method, and so this is the one that will be returned (hashed etc.) The net effect of this is that the the checksum is evaluated on the message alone - which in theory means that I can standardise the message and keep the user definition unique. I've answered my own question here, but hopefully my investigation is of use to others having the same problem. (As an aside, I've also submitted a pull request against the Sentry documentation as part of this ;-)) (Note to anyone using / extending Sentry with custom interfaces - if you want to avoid your interface being use to group exceptions, return an empty list.)

  Read the article

• JSF SelectOneMenuItem onselect attribute

  - by William

  I have created selectOneMenuItem(JSF).I placed my events on valueChangeListener / onchange like that <h:selectOneMenu id="ddl" value="#{Foo.attr}" onchange="submit()" valueChangeListener="#{Foo.renderFoo}"> When I select one vlaue from selectOneMenuItem then event fires.Now when I reselect that value ,then event doesn't fire (because this is the valueChangeListener event) so it doesn't fire.I want that event should fire on every selection even on again the same selection.I found onselect but unable to find that is it right and how can i use this onselect.Anyu help would be greatly appreciable

  Read the article

• List View Selected Index Changed in a multi-selectable list view

  - by Anton Indrawan

  I have a windows form with a listview control. I set the MultiSelect property to true and I added a selected_index changed event. I get the event fired when I click the same index as the current selected index. My expectation is that I will not get the event fired. The strange thing is that the event fired 1 second after I click the index. I appreciate for any reply to explain why this is happening.

  Read the article

• CGAffineTransformMakeRotation goes the other way after 180 degrees (-3.14)

  - by TheKillerDev

  So, i am trying to do a very simple disc rotation (2d), according to the user touch on it, just like a DJ or something. It is working, but there is a problem, after certain amount of rotation, it starts going backwards, this amount is after 180 degrees or as i saw in while logging the angle, -3.14 (pi). I was wondering, how can i achieve a infinite loop, i mean, the user can keep rotating and rotating to any side, just sliding his finger? Also a second question is, is there any way to speed up the rotation? Here is my code right now: #import <UIKit/UIKit.h> @interface Draggable : UIImageView { CGPoint firstLoc; UILabel * fred; double angle; } @property (assign) CGPoint firstLoc; @property (retain) UILabel * fred; @end @implementation Draggable @synthesize fred, firstLoc; - (id)initWithFrame:(CGRect)frame { self = [super initWithFrame:frame]; angle = 0; if (self) { // Initialization code } return self; } -(void)handleObject:(NSSet *)touches withEvent:(UIEvent *)event isLast:(BOOL)lst { UITouch *touch =[[[event allTouches] allObjects] lastObject]; CGPoint curLoc = [touch locationInView:self]; float fromAngle = atan2( firstLoc.y-self.center.y, firstLoc.x-self.center.x ); float toAngle = atan2( curLoc.y-(self.center.y+10), curLoc.x-(self.center.x+10)); float newAngle = angle + (toAngle - fromAngle); NSLog(@"%f",newAngle); CGAffineTransform cgaRotate = CGAffineTransformMakeRotation(newAngle); self.transform = cgaRotate; if (lst) angle = newAngle; } -(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch =[[[event allTouches] allObjects] lastObject]; firstLoc = [touch locationInView:self]; }; -(void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { [self handleObject:touches withEvent:event isLast:NO]; }; -(void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { [self handleObject:touches withEvent:event isLast:YES]; } @end And in the ViewController: UIImage *tmpImage = [UIImage imageNamed:@"theDisc.png"]; CGRect cellRectangle; cellRectangle = CGRectMake(-1,self.view.frame.size.height,tmpImage.size.width ,tmpImage.size.height ); dragger = [[Draggable alloc] initWithFrame:cellRectangle]; [dragger setImage:tmpImage]; [dragger setUserInteractionEnabled:YES]; dragger.layer.anchorPoint = CGPointMake(.5,.5); [self.view addSubview:dragger]; I am open to new/cleaner/more correct ways of doing this too. Thanks in advance.

  Read the article

• Selecting id of TextArea (despite RichEditableText)

  - by duder

  I'm trying to select the id of a textArea when it's focused in <s:TextArea id="textarea1" focusIn="selectId(event)" /> selectId(event){ event.target.id; } Problem is TextArea is made up of RichEditableText so target doesn't actually refer to TextArea. I've tried event.target.parent.id but still not getting there. Anyone knows how to get to the bottom of this?

  Read the article

• retriving row of grid

  - by madhu

  i have data grid to which data is getting from database.after getting the data i hvve to show entire row information in an alert box.can any one help me thanks in advance. my function code is private function fetch(event:Event):void { var selectedRow:Object = event.currentTarget.selectedItem; Alert.show(""+selectedRow.Details); } iam calling this method on click event of grid

  Read the article

• How do I create a class in Javascript?

  - by William

  This is what I got so far, and it's not working at all :( <!DOCTYPE html> <html lang="en"> <head> <title>Class Test</title> <meta charset="utf-8" /> <style> body { text-align: center; background-color: #ffffff;} #box { position: absolute; left: 610px; top: 80px; height: 50px; width: 50px; background-color: #ff0000; color: #000000;} </style> <script type="text/javascript"> document.onkeydown=function(event){keyDown(event)}; document.onkeyup=function(event){keyUp(event)}; var box = 0; function Player () { var speed = 5; var x = 50; var y = 50; } function update() { box.style.left = this.x + "px"; box.style.top = this.y + "px"; box.innerHTML = "<h6 style=\"margin: 0px 0px 0px 0px; padding: 0px 0px 0px 0px;\">X: "+ this.x + "<br /> Y: " + this.y + "</h6>"; } var player = new Player(); var keys = new Array(256); var i = 0; for (i = 0;i <= 256; i++){ keys[i] = false; } function keyDown(event){ keys[event.keyCode] = true; } function keyUp(event){ keys[event.keyCode] = false; } function update(){ if(keys[37]) player.x -= player.speed; if(keys[39]) player.x += player.speed; player.update(); } setInterval(update, 1000/60); </script> </head> <body> <div id="box" ></div> <script type="text/javascript"> box = document.getElementById('box'); box.innerHTML = "<h6 style=\"margin: 0px 0px 0px 0px; padding: 0px 0px 0px 0px;\">X: "+ player.x + "<br /> Y: " + player.y + "</h6>"; </script> </body> </html>

  Read the article

• locking on dictionary of structs not working between 2 threads?

  - by Rancur3p1c

  C#, .Net2.0, XP, Zen I have 2 threads accessing a shared dictionary of structures, each thread via an event. At the beginning of the event I lock the dictionary, remove some structures, and exit the lock+event. Yet somehow the 2nd thread|event is finding some of the removed structures. Conceptually I must be doing something wrong for this to be happening? I thought locking was supposed to make it thread safe?

  Read the article

• Problem using FormView to insert.

  - by matthew_360

  I have a formview control, and on the ItemCreated event, I am "priming" some of the fields with default values. However, when I try to use the formview to insert, before the ItemInserting event gets called, for some reason it calls ItemCreated first. That results in the fields being over-written with the default values right before the insert happens. How do I get it to not call the ItemCreated event before the ItemInserting event?

  Read the article

• ResizeEvent Looping?

  - by user309235

  Hello all, I am having an issue with an actionscript event that I am firing every time a flex componenet resizes. In the event, I am altering the height of the component (adding a bit of a buffer), which causes the event to loop in upon itself and continually add height to the component. Is there an elegant way to have this event only fire once?

  Read the article

• Linux signals with extra information parameter

  - by Tester

  I was to have some extra information in the callback to sa_sigaction handler, it does not seems possible. So I was wondering if you could suggest me alternatives. Basic requirements: Function A raises an signal/event with a pointer to a struct Handler function tackles the event. The handler function would only be called on an event and a loop to wait for the event, as in select() , is undesirable. TIA

  Read the article

• i can't get variable in function.

  - by kaym

  i can't read the variable in the function, i want to use it outside the function, here is my code. var contentLoader:URLLoader = new URLLoader(); contentLoader.load(new URLRequest("http://localhost/data.php")); function onComplete(event:Event):void { var txtu:String = event.target.data; } contentLoader.addEventListener(Event.COMPLETE, onComplete); trace(txtu); thanks.

  Read the article

• Using bind( type, [data], fn ) and non-inline function

  - by dalizard

  $("p").bind("click", function(event){ // code goes here }); This is quite understandable. But what is the way to use a non-inline function and pass the event as an argument? That is: $("p").bind("click", myFunction(event)); function myFunction(event) { // code goes here } Thank you!

  Read the article

• facebook events to rss feed?

  - by Haroldo

  it looks like there used to be an export events button (to rss) but fb have removed it, i've looked at fbCal but it only exports the event name and the link to the event, but none of the event details. anyone got any ideas of how i can get multiple event details out of facebook?

  Read the article

• Basics of Join Predicate Pushdown in Oracle

  - by Maria Colgan

  Happy New Year to all of our readers! We hope you all had a great holiday season. We start the new year by continuing our series on Optimizer transformations. This time it is the turn of Predicate Pushdown. I would like to thank Rafi Ahmed for the content of this blog.Normally, a view cannot be joined with an index-based nested loop (i.e., index access) join, since a view, in contrast with a base table, does not have an index defined on it. A view can only be joined with other tables using three methods: hash, nested loop, and sort-merge joins. Introduction The join predicate pushdown (JPPD) transformation allows a view to be joined with index-based nested-loop join method, which may provide a more optimal alternative. In the join predicate pushdown transformation, the view remains a separate query block, but it contains the join predicate, which is pushed down from its containing query block into the view. The view thus becomes correlated and must be evaluated for each row of the outer query block. These pushed-down join predicates, once inside the view, open up new index access paths on the base tables inside the view; this allows the view to be joined with index-based nested-loop join method, thereby enabling the optimizer to select an efficient execution plan. The join predicate pushdown transformation is not always optimal. The join predicate pushed-down view becomes correlated and it must be evaluated for each outer row; if there is a large number of outer rows, the cost of evaluating the view multiple times may make the nested-loop join suboptimal, and therefore joining the view with hash or sort-merge join method may be more efficient. The decision whether to push down join predicates into a view is determined by evaluating the costs of the outer query with and without the join predicate pushdown transformation under Oracle's cost-based query transformation framework. The join predicate pushdown transformation applies to both non-mergeable views and mergeable views and to pre-defined and inline views as well as to views generated internally by the optimizer during various transformations. The following shows the types of views on which join predicate pushdown is currently supported. UNION ALL/UNION view Outer-joined view Anti-joined view Semi-joined view DISTINCT view GROUP-BY view Examples Consider query A, which has an outer-joined view V. The view cannot be merged, as it contains two tables, and the join between these two tables must be performed before the join between the view and the outer table T4. A: SELECT T4.unique1, V.unique3 FROM T_4K T4,            (SELECT T10.unique3, T10.hundred, T10.ten             FROM T_5K T5, T_10K T10             WHERE T5.unique3 = T10.unique3) VWHERE T4.unique3 = V.hundred(+) AND       T4.ten = V.ten(+) AND       T4.thousand = 5; The following shows the non-default plan for query A generated by disabling join predicate pushdown. When query A undergoes join predicate pushdown, it yields query B. Note that query B is expressed in a non-standard SQL and shows an internal representation of the query. B: SELECT T4.unique1, V.unique3 FROM T_4K T4,           (SELECT T10.unique3, T10.hundred, T10.ten             FROM T_5K T5, T_10K T10             WHERE T5.unique3 = T10.unique3             AND T4.unique3 = V.hundred(+)             AND T4.ten = V.ten(+)) V WHERE T4.thousand = 5; The execution plan for query B is shown below. In the execution plan BX, note the keyword 'VIEW PUSHED PREDICATE' indicates that the view has undergone the join predicate pushdown transformation. The join predicates (shown here in red) have been moved into the view V; these join predicates open up index access paths thereby enabling index-based nested-loop join of the view. With join predicate pushdown, the cost of query A has come down from 62 to 32.  As mentioned earlier, the join predicate pushdown transformation is cost-based, and a join predicate pushed-down plan is selected only when it reduces the overall cost. Consider another example of a query C, which contains a view with the UNION ALL set operator.C: SELECT R.unique1, V.unique3 FROM T_5K R,            (SELECT T1.unique3, T2.unique1+T1.unique1             FROM T_5K T1, T_10K T2             WHERE T1.unique1 = T2.unique1             UNION ALL             SELECT T1.unique3, T2.unique2             FROM G_4K T1, T_10K T2             WHERE T1.unique1 = T2.unique1) V WHERE R.unique3 = V.unique3 and R.thousand < 1; The execution plan of query C is shown below. In the above, 'VIEW UNION ALL PUSHED PREDICATE' indicates that the UNION ALL view has undergone the join predicate pushdown transformation. As can be seen, here the join predicate has been replicated and pushed inside every branch of the UNION ALL view. The join predicates (shown here in red) open up index access paths thereby enabling index-based nested loop join of the view. Consider query D as an example of join predicate pushdown into a distinct view. We have the following cardinalities of the tables involved in query D: Sales (1,016,271), Customers (50,000), and Costs (787,766).  D: SELECT C.cust_last_name, C.cust_city FROM customers C,            (SELECT DISTINCT S.cust_id             FROM sales S, costs CT             WHERE S.prod_id = CT.prod_id and CT.unit_price > 70) V WHERE C.cust_state_province = 'CA' and C.cust_id = V.cust_id; The execution plan of query D is shown below. As shown in XD, when query D undergoes join predicate pushdown transformation, the expensive DISTINCT operator is removed and the join is converted into a semi-join; this is possible, since all the SELECT list items of the view participate in an equi-join with the outer tables. Under similar conditions, when a group-by view undergoes join predicate pushdown transformation, the expensive group-by operator can also be removed. With the join predicate pushdown transformation, the elapsed time of query D came down from 63 seconds to 5 seconds. Since distinct and group-by views are mergeable views, the cost-based transformation framework also compares the cost of merging the view with that of join predicate pushdown in selecting the most optimal execution plan. Summary We have tried to illustrate the basic ideas behind join predicate pushdown on different types of views by showing example queries that are quite simple. Oracle can handle far more complex queries and other types of views not shown here in the examples. Again many thanks to Rafi Ahmed for the content of this blog post.

  Read the article

• C# Performance Pitfall – Interop Scenarios Change the Rules

  - by Reed

  C# and .NET, overall, really do have fantastic performance in my opinion.  That being said, the performance characteristics dramatically differ from native programming, and take some relearning if you’re used to doing performance optimization in most other languages, especially C, C++, and similar.  However, there are times when revisiting tricks learned in native code play a critical role in performance optimization in C#. I recently ran across a nasty scenario that illustrated to me how dangerous following any fixed rules for optimization can be… The rules in C# when optimizing code are very different than C or C++.  Often, they’re exactly backwards.  For example, in C and C++, lifting a variable out of loops in order to avoid memory allocations often can have huge advantages.  If some function within a call graph is allocating memory dynamically, and that gets called in a loop, it can dramatically slow down a routine. This can be a tricky bottleneck to track down, even with a profiler.  Looking at the memory allocation graph is usually the key for spotting this routine, as it’s often “hidden” deep in call graph.  For example, while optimizing some of my scientific routines, I ran into a situation where I had a loop similar to: for (i=0; i<numberToProcess; ++i) { // Do some work ProcessElement(element[i]); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This loop was at a fairly high level in the call graph, and often could take many hours to complete, depending on the input data.  As such, any performance optimization we could achieve would be greatly appreciated by our users. After a fair bit of profiling, I noticed that a couple of function calls down the call graph (inside of ProcessElement), there was some code that effectively was doing: // Allocate some data required DataStructure* data = new DataStructure(num); // Call into a subroutine that passed around and manipulated this data highly CallSubroutine(data); // Read and use some values from here double values = data->Foo; // Cleanup delete data; // ... return bar; Normally, if “DataStructure” was a simple data type, I could just allocate it on the stack.  However, it’s constructor, internally, allocated it’s own memory using new, so this wouldn’t eliminate the problem.  In this case, however, I could change the call signatures to allow the pointer to the data structure to be passed into ProcessElement and through the call graph, allowing the inner routine to reuse the same “data” memory instead of allocating.  At the highest level, my code effectively changed to something like: DataStructure* data = new DataStructure(numberToProcess); for (i=0; i<numberToProcess; ++i) { // Do some work ProcessElement(element[i], data); } delete data; Granted, this dramatically reduced the maintainability of the code, so it wasn’t something I wanted to do unless there was a significant benefit.  In this case, after profiling the new version, I found that it increased the overall performance dramatically – my main test case went from 35 minutes runtime down to 21 minutes.  This was such a significant improvement, I felt it was worth the reduction in maintainability. In C and C++, it’s generally a good idea (for performance) to: Reduce the number of memory allocations as much as possible, Use fewer, larger memory allocations instead of many smaller ones, and Allocate as high up the call stack as possible, and reuse memory I’ve seen many people try to make similar optimizations in C# code.  For good or bad, this is typically not a good idea.  The garbage collector in .NET completely changes the rules here. In C#, reallocating memory in a loop is not always a bad idea.  In this scenario, for example, I may have been much better off leaving the original code alone.  The reason for this is the garbage collector.  The GC in .NET is incredibly effective, and leaving the allocation deep inside the call stack has some huge advantages.  First and foremost, it tends to make the code more maintainable – passing around object references tends to couple the methods together more than necessary, and overall increase the complexity of the code.  This is something that should be avoided unless there is a significant reason.  Second, (unlike C and C++) memory allocation of a single object in C# is normally cheap and fast.  Finally, and most critically, there is a large advantage to having short lived objects.  If you lift a variable out of the loop and reuse the memory, its much more likely that object will get promoted to Gen1 (or worse, Gen2).  This can cause expensive compaction operations to be required, and also lead to (at least temporary) memory fragmentation as well as more costly collections later. As such, I’ve found that it’s often (though not always) faster to leave memory allocations where you’d naturally place them – deep inside of the call graph, inside of the loops.  This causes the objects to stay very short lived, which in turn increases the efficiency of the garbage collector, and can dramatically improve the overall performance of the routine as a whole. In C#, I tend to: Keep variable declarations in the tightest scope possible Declare and allocate objects at usage While this tends to cause some of the same goals (reducing unnecessary allocations, etc), the goal here is a bit different – it’s about keeping the objects rooted for as little time as possible in order to (attempt) to keep them completely in Gen0, or worst case, Gen1.  It also has the huge advantage of keeping the code very maintainable – objects are used and “released” as soon as possible, which keeps the code very clean.  It does, however, often have the side effect of causing more allocations to occur, but keeping the objects rooted for a much shorter time. Now – nowhere here am I suggesting that these rules are hard, fast rules that are always true.  That being said, my time spent optimizing over the years encourages me to naturally write code that follows the above guidelines, then profile and adjust as necessary.  In my current project, however, I ran across one of those nasty little pitfalls that’s something to keep in mind – interop changes the rules. In this case, I was dealing with an API that, internally, used some COM objects.  In this case, these COM objects were leading to native allocations (most likely C++) occurring in a loop deep in my call graph.  Even though I was writing nice, clean managed code, the normal managed code rules for performance no longer apply.  After profiling to find the bottleneck in my code, I realized that my inner loop, a innocuous looking block of C# code, was effectively causing a set of native memory allocations in every iteration.  This required going back to a “native programming” mindset for optimization.  Lifting these variables and reusing them took a 1:10 routine down to 0:20 – again, a very worthwhile improvement. Overall, the lessons here are: Always profile if you suspect a performance problem – don’t assume any rule is correct, or any code is efficient just because it looks like it should be Remember to check memory allocations when profiling, not just CPU cycles Interop scenarios often cause managed code to act very differently than “normal” managed code. Native code can be hidden very cleverly inside of managed wrappers

  Read the article

• Teamviewer: cannot control monitor 1, but can control monitor 2

  - by DaveT

  I'm using the web client of Teamviewer from my work computer trying to control my home computer. I have 2 monitors on the remote desktop, but for some reason only have control on the second monitor. When I switch to the main monitor (monitor 1), I cannot do anything and cannot even move the cursor. But I have no issues when I switch over to the second monitor (monitor 2). I used to have no issues with either, but in the past couple of months this has been causing me issues. Anyone have a suggestion? Thanks!! Also... Here is the log from the Teamviewer session. Showing me switching back and forth between the monitors. (just in case this will help). I had to remove the links in order to post the log since I don't have enough reputation points, but they were just teamviewer login weblinks. =============================================================================== 21.08 16:00:41,176: Version: 9.0.15099 21.08 16:00:41,177: Sandbox: remote 21.08 16:00:41,177: SysLanguage: en 21.08 16:00:41,177: VarLanguage: en 21.08 16:00:41,177: Flash Player: PlugIn (WIN 14,0,0,179) 21.08 16:00:41,178: UseLanguage: en 21.08 16:00:41,178: UseLanguage: en 21.08 16:00:41,182: TeamViewer hasPassword: true 21.08 16:00:41,418: ExternalConnect id=910035824 21.08 16:00:41,419: CT connect 910035824 masterURL: , sandbox = remote 21.08 16:00:41,425: MC.requestRoute(910035824) 21.08 16:00:41,426: MC.sendMasterCommand text=F=RequestRoute2&ID1=777&Client=TV& ID2=910035824&SA_AccountID=26641022&SA_PasswordMD5HashBase64Encoded=& SA_SessionSecret=f7H6Z7SYfX5ahQ7SJq/r/K20PBYg9fOZhp+DKLhf5ts=&SA_SessionID=1558929948& V=9.0.15099&OS=Flash 21.08 16:00:41,426: MC wait for ping completion 21.08 16:00:42,064: PS.socket event: [Event type="connect" bubbles=false cancelable=false eventPhase=2] 21.08 16:00:42,182: PingThread: TCP-Ping ok 21.08 16:00:42,183: MC.socket mode = TCP, MasterURL: 21.08 16:00:42,183: MC.connect: 21.08 16:00:43,058: PS.socket event: [Event type="connect" bubbles=false cancelable=false eventPhase=2] 21.08 16:00:43,058: MC.connectHandler: [Event type="connect" bubbles=false cancelable=false eventPhase=2] 21.08 16:00:43,236: MC.requestRouteResponse: [email protected]_10800_128000_762319420_910035824_10000__1_0_16778176_128000_16778176: 128000;2147483647:1280000;4:640000_786297_786297 21.08 16:00:43,239: CT init socket: TCP 21.08 16:00:43,513: PS.socket event: [Event type="connect" bubbles=false cancelable=false eventPhase=2] 21.08 16:00:43,514: CT.connectHandler: [Event type="connect" bubbles=false cancelable=false eventPhase=2] 21.08 16:00:43,519: Browser name: Netscape 21.08 16:00:43,936: CMD_IDENTIFY id=910035824 ver=2.41 21.08 16:00:44,666: CMD_CONFIRMENCRYPTION: encryption confirmed 21.08 16:00:44,667: Started resendrequest timer 21.08 16:00:45,063: Remote Version: TV 009.000 21.08 16:00:45,501: start classic authentication 21.08 16:00:45,502: Login::SendRequestToConsole(): url= 21.08 16:00:45,828: start srp authentication 21.08 16:00:46,983: checkFirstPacket ok, m_LastReceivedPacketID =4 21.08 16:00:47,148: Login::SendRequestToConsole(): url= 21.08 16:00:47,478: start srp authentication 21.08 16:00:48,210: Login::SendRequestToConsole(): url= 21.08 16:00:48,485: checkFirstPacket ok, m_LastReceivedPacketID =7 21.08 16:00:48,780: TVCmdAuthenticate_Authenticated: 1 21.08 16:00:49,321: Connected to 910035824, name=NEWMAN, os=14, version=9.0.31064 21.08 16:00:49,329: ConnectionAccessSettings: RemoteControl: AllowedFileTransfer: AllowedControlRemoteTV: AllowedSwitchSides: DeniedAllowDisableRemoteInput: AllowedAllowVPN: AllowedAllowPartnerViewDesktop: Allowed 21.08 16:00:52,195: unexpected TVCommand.CommandType == 56 21.08 16:00:52,231: CW received display params: 1680x1050x8 monitors: 2 (active:0) 21.08 16:00:52,301: Caching active, version=2 21.08 16:03:47,158: CW received display params: 1680x1050x8 monitors: 2 (active:1) 21.08 16:04:24,447: CW received display params: 1680x1050x8 monitors: 2 (active:0) 21.08 16:04:40,609: CW received display params: 3360x1050x8 monitors: 2 (active:-1) 21.08 16:04:59,802: CW received display params: 1680x1050x8 monitors: 2 (active:1) 21.08 16:04:59,933: CW received display params: 1680x1050x8 monitors: 2 (active:1) 21.08 16:05:58,419: CW received display params: 1680x1050x8 monitors: 2 (active:0) 21.08 16:06:36,824: CW received display params: 1680x1050x8 monitors: 2 (active:1) 21.08 16:07:07,232: CW received display params: 1680x1050x8 monitors: 2 (active:0)

  Read the article

• IIS 7.5 + Windows Server 2008 R2 + ASP.NET 4.0 HTTP 500 Error?

  - by Dave

  Hi, I'm having an issue I cannot track down and I have looked through the forums and not found anything that sheds any light. I have a fresh install of a Server 2008 R2 Web that I am trying to load an application I created and tested on a Windows 7 machine running IIS 7.5 using ASP.NET 4.0. Everything works fine on the dev machine. But when I used the Web Deployment tool to move it to the server, I now get a HTTP 500 error without a lot of information: Module AspNetInitClrHostFailureModule Notification BeginRequest Handler StaticFile Error Code 0x80070002 Requested URL http://192.168.1.83:80/ Physical Path C:\JustStreamIt Logon Method Not yet determined Logon User Not yet determined Failed Request Tracing Log Directory C:\inetpub\logs\FailedReqLogFiles And in my trace file I get: view trace Warning -SET_RESPONSE_ERROR_DESCRIPTION ErrorDescription An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Please review this log entry to discover what caused this error to occur. view trace Warning -MODULE_SET_RESPONSE_ERROR_STATUS ModuleName AspNetInitClrHostFailureModule Notification 1 HttpStatus 500 HttpReason Internal Server Error HttpSubStatus 0 ErrorCode 2147942402 ConfigExceptionInfo Notification BEGIN_REQUEST ErrorCode The system cannot find the file specified. (0x80070002) And I get the following in the Application Log: Log Name: Application Source: Microsoft-Windows-IIS-W3SVC-WP Date: 5/28/2010 2:08:10 PM Event ID: 2299 Task Category: None Level: Error Keywords: Classic User: N/A Computer: win-ltfkdo1dnfp Description: An application has reported as being unhealthy. The worker process will now request a recycle. Reason given: An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Please review this log entry to discover what caused this error to occur. . The data is the error. Event Xml: <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"> <System> <Provider Name="Microsoft-Windows-IIS-W3SVC-WP" Guid="{670080D9-742A-4187-8D16-41143D1290BD}" EventSourceName="W3SVC-WP" /> <EventID Qualifiers="49152">2299</EventID> <Version>0</Version> <Level>2</Level> <Task>0</Task> <Opcode>0</Opcode> <Keywords>0x80000000000000</Keywords> <TimeCreated SystemTime="2010-05-28T21:08:10.000000000Z" /> <EventRecordID>1663</EventRecordID> <Correlation /> <Execution ProcessID="0" ThreadID="0" /> <Channel>Application</Channel> <Computer>win-ltfkdo1dnfp</Computer> <Security /> </System> <EventData> <Data Name="Reason">An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Please review this log entry to discover what caused this error to occur. </Data> <Binary>02000780</Binary> </EventData> </Event> Anyone have a suggestion about where I should start looking?

  Read the article

< Previous Page | 203 204 205 206 207 208 209 210 211 212 213 214  | Next Page >