Search Results

Search found 61986 results on 2480 pages for 'launch time'.

Page 593/2480 | < Previous Page | 589 590 591 592 593 594 595 596 597 598 599 600  | Next Page >

  • Ubuntu 12.04 LTS loops the login screen unless you login as Guest

    - by Mário Silva
    I am running a VMWare Player with a Ubuntu 12.04 LTS Precise Pangloin as Guest on my Windows 7. Sometimes I get the shutdown blue screen error in Windows, this time it happened when I was running the Player. When I restarted everything Ubuntu gave the not so unfamiliar in this forum Login Loop in adminstrator login. I login and there's this black screen where I can only read: "piix4...smbus:0.0.0.07.3 Host Smbus controller not enabled" . When I go to the Prompt in root mode it fails to update and only upgraded, specially some plugins ( I think graphic plugins) which also appear in one an error message after quitting the prompt, but they´are successfully installed. They are not the error message. After that I have been working with the Fail/safe Mode recovery panel. When I try to update via Root I get errors like this: W:failed to fetch http://extras.ubuntu.com/ubuntu/dists/precise/release.gpg could not resolve 'extras/ubuntu.com There are 8 more like this referring to areas like: -archive/canonical.com -ppa.Launchpad.net -security.Ubuntu.com -Us.archive.ubuntu.com - release.gpg precise-updates/release.gpg precise_backport/release.gpg Final Message: some index files failed to download.....they have been ignored or old files are used. The black screens most of the time pass by too fast for me to pick up any information. But in general I think I have done everything I was able to in the recovery panel including updating network and graphic packages and recovering filesystem packages and the basic stuff ( I am a beginner regarding Linux ) in the root prompt. Now I am stuck in this screen with graphic options: - Run in low-graphics mode just for one session - Reconfigure Graphics - Troubleshoot the error - Exit to console login I am trying to choose to reconfigure graphics but the mouse disappears in the virtual machine screen and sometimes when options change ity´s only the first and last option. ut this happens from the blue without messages. This particular option menu is in the regular GUI style against a black screen in Terminal style. Really strange. Thanx in advance, all is welcome and appreciated.

    Read the article

  • Pygame surfaces and their Rects

    - by Jaka Novak
    I am trying to understand how pygame surfaces work. I am confused about Rect position of Surface object. If I try blit surface on screen at some position then Surface is drawn at right position, but Rect of the surface is still at position (0, 0)... I tried write my own surface class with new rect, but i am not sure if is that right solution. My goal is that i could move surface like image with rect.move() or something like that. If there is any solution to do that i would be happy to read it. Thanks for answer and time for reading this awful English If helps i write some code for better understanding my problem. (run it first, and then uncomment two lines of code and run again to see the diference): import pygame from pygame.locals import * class SurfaceR(pygame.Surface): def __init__(self, size, position): pygame.Surface.__init__(self, size) self.rect = pygame.Rect(position, size) self.position = position self.size = size def get_rect(self): return self.rect def main(): pygame.init() screen = pygame.display.set_mode((640, 480)) pygame.display.set_caption("Screen!?") clock = pygame.time.Clock() fps = 30 white = (255, 255, 255) red = (255, 0, 0) green = (0, 255, 0) blue = (0, 0, 255) surface = pygame.Surface((70,200)) surface.fill(red) surface_re = SurfaceR((300, 50), (100, 300)) surface_re.fill(blue) while True: for event in pygame.event.get(): if event.type == QUIT: return 0 screen.blit(surface, (100,50)) screen.blit(surface_re, surface_re.position) #pygame.draw.rect(screen, white, surface.get_rect()) #pygame.draw.rect(screen, white, surface_re.get_rect()) pygame.display.update() clock.tick(fps) if __name__ == "__main__": main()

    Read the article

  • how do I write a functional specification quickly and efficiently

    - by giddy
    So I just read some fabulous articles by Joel on specs here. (Was written in 2000!!) I read all 4 parts, but Im looking for some methodical approaches to writing my specs. Im the only lonely dev, working on this fairly complicated app (or family of apps) for a very well known finance company. I've never made something this serious, I started out writing something like a bad spec, an overview of some sorts, and it has wasted a LOT of my time. Ive also made 3 mockup-kinda-thingies for my client so I have a good understanding of what they want. Also released a preview (a throw away working app with the most basic workflow), and Ive only written and tested some of the very core/base systems. I think the mistake Ive been making so far is not writing a detailed spec, so Im getting to it now. So the whole thing comprises of An MVC website (for admins & data viewing) 2 Silverlight modules (For 2 specific tasks) 1 Desktop Application Im totally short on time, resources and need to get this done quick, also, need to make sure these guys read it up equally quick and painlessly. So how do I go about it, Im looking for any tips, any real world stuff, how do you guys usually do it? Do you make a mock screenie of every dialog/form/page? Im thinking of making a dummy asp.net web forms project, then filling in html files in folders and making it look like my mvc url structure. Then having a section in the spec for the website and write up a page for every URL Ive got with a screenie. For my win forms app, Ive made somewhat of a demo Win Form project, would I then put in a dialog or stucture everything as I would in the real app and then screen shot it?

    Read the article

  • Solaris: What comes next?

    - by alanc
    As you probably know by now, a few months ago, we released Solaris 11 after years of development. That of course means we now need to figure out what comes next - if Solaris 11 is “The First Cloud OS”, then what do we need to make future releases of Solaris be, to be modern and competitive when they're released? So we've been having planning and brainstorming meetings, and I've captured some notes here from just one of those we held a couple weeks ago with a number of the Silicon Valley based engineers. Now before someone sees an idea here and calls their product rep wanting to know what's up, please be warned what follows are rough ideas, and as I'll discuss later, none of them have any committment, schedule, working code, or even plan for integration in any possible future product at this time. (Please don't make me force you to read the full Oracle future product disclaimer here, you should know it by heart already from the front of every Oracle product slide deck.) To start with, we did some background research, looking at ideas from other Oracle groups, and competitive OS'es. We examined what was hot in the technology arena and where the interesting startups were heading. We then looked at Solaris to see where we could apply those ideas. Making Network Admins into Socially Networking Admins We all know an admin who has grumbled about being the only one stuck late at work to fix a problem on the server, or having to work the weekend alone to do scheduled maintenance. But admins are humans (at least most are), and crave companionship and community with their fellow humans. And even when they're alone in the server room, they're never far from a network connection, allowing access to the wide world of wonders on the Internet. Our solution here is not building a new social network - there's enough of those already, and Oracle even has its own Oracle Mix social network already. What we proposed is integrating Solaris features to help engage our system admins with these social networks, building community and bringing them recognition in the workplace, using achievement recognition systems as found in many popular gaming platforms. For instance, if you had a Facebook account, and a group of admin friends there, you could register it with our Social Network Utility For Facebook, and then your friends might see: Alan earned the achievement Critically Patched (April 2012) for patching all his servers. Matt is only at 50% - encourage him to complete this achievement today! To avoid any undue risk of advertising who has unpatched servers that are easier targets for hackers to break into, this information would be tightly protected via Facebook's world-renowned privacy settings to avoid it falling into the wrong hands. A related form of gamification we considered was replacing simple certfications with role-playing-game-style Experience Levels. Instead of just knowing an admin passed a test establishing a given level of competency, these would provide recruiters with a more detailed level of how much real-world experience an admin has. Achievements such as the one above would feed into it, but larger numbers of experience points would be gained by tougher or more critical tasks - such as recovering a down system, or migrating a service to a new platform. (As long as it was an Oracle platform of course - migrating to an HP or IBM platform would cause the admin to lose points with us.) Unfortunately, we couldn't figure out a good way to prevent (if you will) “gaming” the system. For instance, a disgruntled admin might decide to start ignoring warnings from FMA that a part is beginning to fail or skip preventative maintenance, in the hopes that they'd cause a catastrophic failure to earn more points for bolstering their resume as they look for a job elsewhere, and not worrying about the effect on your business of a mission critical server going down. More Z's for ZFS Our suggested new feature for ZFS was inspired by the worlds most successful Z-startup of all time: Zynga. Using the Social Network Utility For Facebook described above, we'd tie it in with ZFS monitoring to help you out when you find yourself in a jam needing more disk space than you have, and can't wait a month to get a purchase order through channels to buy more. Instead with the click of a button you could post to your group: Alan can't find any space in his server farm! Can you help? Friends could loan you some space on their connected servers for a few weeks, knowing that you'd return the favor when needed. ZFS would create a new filesystem for your use on their system, and securely share it with your system using Kerberized NFS. If none of your friends have space, then you could buy temporary use space in small increments at affordable rates right there in Facebook, using your Facebook credits, and then file an expense report later, after the urgent need has passed. Universal Single Sign On One thing all the engineers agreed on was that we still had far too many "Single" sign ons to deal with in our daily work. On the web, every web site used to have its own password database, forcing us to hope we could remember what login name was still available on each site when we signed up, and which unique password we came up with to avoid having to disclose our other passwords to a new site. In recent years, the web services world has finally been reducing the number of logins we have to manage, with many services allowing you to login using your identity from Google, Twitter or Facebook. So we proposed following their lead, introducing PAM modules for web services - no more would you have to type in whatever login name IT assigned and try to remember the password you chose the last time password aging forced you to change it - you'd simply choose which web service you wanted to authenticate against, and would login to your Solaris account upon reciept of a cookie from their identity service. Pinning notes to the cloud We also all noted that we all have our own pile of notes we keep in our daily work - in text files in our home directory, in notebooks we carry around, on white boards in offices and common areas, on sticky notes on our monitors, or on scraps of paper pinned to our bulletin boards. The contents of the notes vary, some are things just for us, some are useful for our groups, some we would share with the world. For instance, when our group moved to a new building a couple years ago, we had a white board in the hallway listing all the NIS & DNS servers, subnets, and other network configuration information we needed to set up our Solaris machines after the move. Similarly, as Solaris 11 was finishing and we were all learning the new network configuration commands, we shared notes in wikis and e-mails with our fellow engineers. Users may also remember one of the popular features of Sun's old BigAdmin site was a section for sharing scripts and tips such as these. Meanwhile, the online "pin board" at Pinterest is taking the web by storm. So we thought, why not mash those up to solve this problem? We proposed a new BigAddPin site where users could “pin” notes, command snippets, configuration information, and so on. For instance, once they had worked out the ideal Automated Installation manifest for their app server, they could pin it up to share with the rest of their group, or choose to make it public as an example for the world. Localized data, such as our group's notes on the servers for our subnet, could be shared only to users connecting from that subnet. And notes that they didn't want others to see at all could be marked private, such as the list of phone numbers to call for late night pizza delivery to the machine room, the birthdays and anniversaries they can never remember but would be sleeping on the couch if they forgot, or the list of automatically generated completely random, impossible to remember root passwords to all their servers. For greater integration with Solaris, we'd put support right into the command shells — redirect output to a pinned note, set your path to include pinned notes as scripts you can run, or bring up your recent shell history and pin a set of commands to save for the next time you need to remember how to do that operation. Location service for Solaris servers A longer term plan would involve convincing the hardware design groups to put GPS locators with wireless transmitters in future server designs. This would help both admins and service personnel trying to find servers in todays massive data centers, and could feed into location presence apps to help show potential customers that while they may not see many Solaris machines on the desktop any more, they are all around. For instance, while walking down Wall Street it might show “There are over 2000 Solaris computers in this block.” [Note: this proposal was made before the recent media coverage of a location service aggregrator app with less noble intentions, and in hindsight, we failed to consider what happens when such data similarly falls into the wrong hands. We certainly wouldn't want our app to be misinterpreted as “There are over $20 million dollars of SPARC servers in this building, waiting for you to steal them.” so it's probably best it was rejected.] Harnessing the power of the GPU for Security Most modern OS'es make use of the widespread availability of high powered GPU hardware in today's computers, with desktop environments requiring 3-D graphics acceleration, whether in Ubuntu Unity, GNOME Shell on Fedora, or Aero Glass on Windows, but we haven't yet made Solaris fully take advantage of this, beyond our basic offering of Compiz on the desktop. Meanwhile, more businesses are interested in increasing security by using biometric authentication, but must also comply with laws in many countries preventing discrimination against employees with physical limations such as missing eyes or fingers, not to mention the lost productivity when employees can't login due to tinted contacts throwing off a retina scan or a paper cut changing their fingerprint appearance until it heals. Fortunately, the two groups considering these problems put their heads together and found a common solution, using 3D technology to enable authentication using the one body part all users are guaranteed to have - pam_phrenology.so, a new PAM module that uses an array USB attached web cams (or just one if the user is willing to spin their chair during login) to take pictures of the users head from all angles, create a 3D model and compare it to the one in the authentication database. While Mythbusters has shown how easy it can be to fool common fingerprint scanners, we have not yet seen any evidence that people can impersonate the shape of another user's cranium, no matter how long they spend beating their head against the wall to reshape it. This could possibly be extended to group users, using modern versions of some of the older phrenological studies, such as giving all users with long grey beards access to the System Architect role, or automatically placing users with pointy spikes in their hair into an easy use mode. Unfortunately, there are still some unsolved technical challenges we haven't figured out how to overcome. Currently, a visit to the hair salon causes your existing authentication to expire, and some users have found that shaving their heads is the only way to avoid bad hair days becoming bad login days. Reaction to these ideas After gathering all our notes on these ideas from the engineering brainstorming meeting, we took them in to present to our management. Unfortunately, most of their reaction cannot be printed here, and they chose not to accept any of these ideas as they were, but they did have some feedback for us to consider as they sent us back to the drawing board. They strongly suggested our ideas would be better presented if we weren't trying to decipher ink blotches that had been smeared by the condensation when we put our pint glasses on the napkins we were taking notes on, and to that end let us know they would not be approving any more engineering offsites in Irish themed pubs on the Friday of a Saint Patrick's Day weekend. (Hopefully they mean that situation specifically and aren't going to deny the funding for travel to this year's X.Org Developer's Conference just because it happens to be in Bavaria and ending on the Friday of the weekend Oktoberfest starts.) They recommended our research techniques could be improved over just sitting around reading blogs and checking our Facebook, Twitter, and Pinterest accounts, such as considering input from alternate viewpoints on topics such as gamification. They also mentioned that Oracle hadn't fully adopted some of Sun's common practices and we might have to try harder to get those to be accepted now that we are one unified company. So as I said at the beginning, don't pester your sales rep just yet for any of these, since they didn't get approved, but if you have better ideas, pass them on and maybe they'll get into our next batch of planning.

    Read the article

  • Per-vertex animation with VBOs: VBO per character or VBO per animation?

    - by charstar
    Goal To leverage the richness of well vetted animation tools such as Blender to do the heavy lifting for a small but rich set of animations. I am aware of additive pose blending like that from Naughty Dog and similar techniques but I would prefer to expend a little RAM/VRAM to avoid implementing a thesis-ready pose solver. I would also like to avoid implementing a key-frame + interpolation curve solver (reinventing Blender vertex groups and IPOs), if possible. Scenario Meshes are animated using either skeletons (skinned animation) or some form of morph targets (i.e. per-vertex key frames). However, in either case, the animations are known in full at load-time, that is, there is no physics, IK solving, or any other form of in-game pose solving. The number of character actions (animations) will be limited but rich (hand-animated). There may be multiple characters using a each mesh and its animations simultaneously in-game (they will likely be at different frames of the same animation at the same time). Assume color and texture coordinate buffers are static. Current Considerations Much like a non-shader-powered pose solver, create a VBO for each character and copy vertex and normal data to each VBO on each frame (VBO in STREAMING). Create one VBO for each animation where each frame (interleaved vertex and normal data) is concatenated onto the VBO. Then each character simply has a buffer pointer offset based on its current animation frame (e.g. pointer offset = (numVertices+numNormals)*frameNumber). (VBO in STATIC) Known Trade-Offs In 1 above: Each VBO would be small but there would be many VBOs and therefore lots of buffer binding and vertex copying each frame. Both client and pipeline intensive. In 2 above: There would be few VBOs therefore insignificant buffer binding and no vertex data getting jammed down the pipe each frame, but each VBO would be quite large. Are there any pitfalls to number 2 (aside from finite memory)? I've found a lot of information on what you can do, but no real best practices. Are there other considerations or methods that I am missing?

    Read the article

  • SQL Contest – Result of Cartoon Contest

    - by pinaldave
    Earlier we had an excellent contest ran with the help of Embarcadero Technologies. We had two different contests on the same day sponsored by the kind folks at Embarcadero. Here are the details of the winners. 1) Win USD 25 Amazon Gift Cards (10 Units) We had announced that we will award USD 25 Amazon Gift Cards to 10 lucky winners who will download the DB Optimizer between Nov 29 to Dec 8. Here is the name of the winners. Winners will get Amazon Gift Cards USD 25 in the next 5 days of this blog post to their registered email address. If you do not receive the card, do send me email (Pinal at sqlauthority.com) and I will follow up on the details. Name of the winners: Ramdas Narayanan Krishna Uppuluri Donna Kray Santosh Gupta Robert Small Samit Bhatt Bernd Baumanns Rodrigo Oriola Jim Woodin Alfred Sandou 2) Win Star Wars R2-D2 Inflatable R/C We had cartoon contest. If you have not read the cartoon – I suggest you go over this cartoon story one more time. The task was to give the correct answer with some interesting note along with it. We selected a few good quotes and put them together. We later on picked the winner by using random algorithm. The winner gets fantastic Star Wars R2-D2 Inflatable R/C. Name of the winner: Aadhar Joshi. He wins R2-D2. You can read his comment over here. Thank you all for participating in the contest – this was fun – if you have liked it do let me know and we will come up with something new for you next time. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • Friday Fun: Wake Up the Box

    - by Mysticgeek
    Another Friday and it’s time to waste the rest of your Friday playing a  fun flash game online. Today we take a look at a relaxing physic based puzzle game called Wake Up the Box. Wake Up the Box This goal of this game is to wake up the box character by attaching parts of existing wood objects in each stage. You can start a new game or continue your progress from where you left off. At the beginning you get a tutorial showing what you need to do to wake the box. You get wood parts and can attach them to other wood pieces but not metal or brick. After successfully waking up Mr. Box, you can go to the next level or restart a level at any time if your having problems figuring out the puzzle. Each level gets more difficult and the puzzles are more challenging. Wake Up the Box is a relaxing and challenging game that will allow you to have fun, not working on TPS reports until the whistle blows. Play Wake Up the Box at FreeWebArcade Similar Articles Productive Geek Tips Stop the Mouse From Waking Up Your Computer from Sleep ModeFix "Sleep Mode Randomly Waking Up" Issue in Windows VistaStop Your Mouse from Waking Up Your Windows 7 ComputerPrevent Windows Asking for a Password on Wake Up from Sleep/StandbyUse Sleep.FM to Wake Up with the Web TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Microsoft’s “How Do I ?” Videos Home Networks – How do they look like & the problems they cause Check Your IMAP Mail Offline In Thunderbird Follow Finder Finds You Twitter Users To Follow Combine MP3 Files Easily QuicklyCode Provides Cheatsheets & Other Programming Stuff

    Read the article

  • iPhone/iPad: Get Alerts When Paid Apps Go Free

    - by Gopinath
    iPhone users has thousands of cool applications to choose. These apps are either paid or absolutely free. Many of the paid applications goes free for either a limited time or forever depending on the mood of their developers. Will it not be cool to get alerts whenever a paid app goes free? Yeah, it will be great. Free App Alert is a handy website that checks iTunes store regularly and sends alerts to it’s subscribers about the apps that have gone from paid to free. You can receive the alerts by following them on twitter, facebook or subscribing to the traditional RSS feeds(yeah RSS is a traditional technology). The home page of this website shows the apps that have gone free today and you can browse through the previous day free apps listing with the help of links available at the bottom. Free App Alert is definitely a cool site to check out for iPhone/iPod/iPad users and certainly easier than scrolling through iTunes store and checking prices. Tip: Immediately download the app that have gone from paid to free as many apps are free for limited time. You can see many free apps going back to paid version if you go through the previous pages the website. Join us on Facebook to read all our stories right inside your Facebook news feed.

    Read the article

  • Difference between Detach/Attach and Restore/BackUp a DB

    - by SAMIR BHOGAYTA
    Transact-SQL BACKUP/RESTORE is the normal method for database backup and recovery. Databases can be backed up while online. The backup file size is usually smaller than the database files since only used pages are backed up. Also, in the FULL or BULK_LOGGED recovery model, you can reduce potential data loss by performing transaction log backups. Detaching a database removes the database from SQL Server while leaving the physical database files intact. This allows you to rename or move the physical files and then re-attach. Although one could perform cold backups using this technique, detach/attach isn't really intended to be used as a backup/recovery process. Commonly it is recommended that you use BACKUP/RESTORE for disaster recovery (DR) scenario and copying data from one location to another. But this is not absolute, sometimes for a very large database, if you want to move it from one location to another, backup/restore process may spend a lot of time which you do not like, in this case, detaching/attaching a database is a better way since you can attach a workable database very fast. But you need to aware that detaching a database will bring it offline for a short time and detaching/attaching does not provide DR function. For more information about detaching and attaching databases, you can refer to: Detaching and Attaching Databases http://technet.microsoft.com/en-us/library/ms190794.aspx

    Read the article

  • Compiz not drawing window controls in ubuntu 11.10

    - by Siva Prasad Varma
    I have recently installed driver for my ATI graphic card in my Dell Studio laptop. I have also read this somewhere on the web that Ubuntu enables compiz window manager by default if your hardware can run it. Is it true ? In my case before Installing graphic card driver the window manager was Metacity, but now I have compiz as my Window manager. I found this out uisng Displex Indicator applet also confirmed by wmctrl -m. From the time I have installed graphic card drivers, the window manager(Compiz) is not drawing window control buttons for some of the windows. For example if I open a terminal I have to close it using key board shortcuts or use the File - Quit option in app-menu. Also I am not able to move the window because of this. From then when-ever I find a window without window control buttons I am restarting the window manager using Displex Indicator applet. But this is very annoying and also consumes a lot of time(when I am doing my work). Can any one suggest any solution for this. What are up's and down's of using Compiz Vs Metacity.

    Read the article

  • Database Developers Can Now Save 20%

    - by stephen.garth
    Database developers can now increase productivity and save money at the same time. For a limited time, Oracle Store is offering a 20% discount on Oracle SQL Developer Data Modeler. Just enter the code SQLDDM at checkout to get the discount. Oracle SQL Developer Data Modeler is an independent, standalone product with a full spectrum of data and database modeling tools and utilities, including modeling for Entity Relationship Diagrams (ERD), Relational (database design), Data Type and Multi-dimensional modeling, full forward and reverse engineering and DDL code generation. SQL Developer Data Modeler can connect to any supported Oracle Database and is platform independent. Save 20% on Oracle SQL Developer Data Modeler at Oracle Store - Discount Code SQLDDM Find out more about Oracle SQL Developer and Oracle SQL Developer Data Modeler var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); try { var pageTracker = _gat._getTracker("UA-13185312-1"); pageTracker._trackPageview(); } catch(err) {}

    Read the article

  • State of the art Culling and Batching techniques in rendering

    - by Kristian Skarseth
    I'm currently working with upgrading and restructuring an OpenGL render engine. The engine is used for visualising large scenes of architectural data (buildings with interior), and the amount of objects can become rather large. As is the case with any building, there is a lot of occluded objects within walls, and you naturally only see the objects that are in the same room as you, or the exterior if you are on the outside. This leaves a large number of objects that should be occluded through occlusion culling and frustum culling. At the same time there is a lot of repetative geometry that can be batched in renderbatches, and also a lot of objects that can be rendered with instanced rendering. The way I see it, it can be difficult to combine renderbatching and culling in an optimal fashion. If you batch too many objects in the same VBO it's difficult to cull the objects on the CPU in order to skip rendering that batch. At the same time if you skip the culling on the cpu, a lot of objects will be processed by the GPU while they are not visible. If you skip batching copletely in order to more easily cull on the CPU, there will be an unwanted high amount of render calls. I have done some research into existing techniques and theories as to how these problems are solved in modern graphics, but I have not been able to find any concrete solution. An idea a colleague and me came up with was restricting batches to objects relatively close to eachother e.g all chairs in a room or within a radius of n meeters. This could be simplified and optimized through use of oct-trees. Does anyone have any pointers to techniques used for scene managment, culling, batching etc in state of the art modern graphics engines?

    Read the article

  • Desktop Fun: Gardens Theme Wallpapers

    - by Asian Angel
    Has your desktop been looking “blah” lately? Now you can add a refreshing burst of color to it with our Gardens Theme Wallpapers collection. Note: Click on the picture to see the full-size image—these wallpapers vary in size so you may need to crop, stretch, or place them on a colored background in order to best match them to your screen’s resolution. For more fun wallpapers be certain to visit our new Desktop Fun section. Similar Articles Productive Geek Tips Windows 7 Welcome Screen Taking Forever? Here’s the Fix (Maybe)Desktop Fun: Starship Theme WallpapersDesktop Fun: Underwater Theme WallpapersDesktop Fun: Forest Theme WallpapersDesktop Fun: Fantasy Theme Wallpapers TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 PCmover Professional Windows 7 Easter Theme YoWindoW, a real time weather screensaver Optimize your computer the Microsoft way Stormpulse provides slick, real time weather data Geek Parents – Did you try Parental Controls in Windows 7? Change DNS servers on the fly with DNS Jumper

    Read the article

  • 2012 Oracle Fusion Middleware Innovation Awards for Oracle Exalogic

    - by Sanjeev Sharma
    Companies from around the world were honored for their innovative solutions using Oracle Fusion Middleware. This year’s 27 award winners, representing 11 countries and a wide span of industries, wowed the judges with a range of projects across eight product categories. 4 awards were given out to customers who demonstrated innovative application of Oracle Exalogic for their mission-critical applications.Below is an overview of the 4 businesses that won the Oracle Fusion Middleware Innovation Award for Oracle Exalogic this year. Company: Netshoes About: Leading online retailer of sporting goods in Latin America.Challenges: Rapid business growth resulted in frequent outages and poor response-time of online store-front Conventional ad-hoc approach to horizontal scaling resulted in high CAPEX and OPEX Poor performance and unavailability of online store-front resulted in revenue loss from purchase abandonment Solution: Consolidated ATG Commerce and Oracle WebLogic running on Oracle Exalogic.Business Impact:Reduced abandonment rates resulting in a two-digit increase in online conversion rates translating directly into revenue up-liftCompany: ClaroAbout: Leading communications services provider in Latin America.Challenges: Support business growth over the next 3  - 5 years while maximizing re-use of existing middleware and application investments with minimal effort and risk Solution: Consolidated Oracle Fusion Middleware components (Oracle WebLogic, Oracle SOA Suite, Oracle Tuxedo) and JAVA applications onto Oracle Exalogic and Oracle Exadata. Business Impact:Improved partner SLA’s 7x while improving throughput 5X and response-time 35x for  JAVA applicationsCompany: ULAbout: Leading safety testing and certification organization in the world.Challenges: Transition from being a non-profit to a profit oriented enterprise and grow from a $1B to $5B in annual revenues in the next 5 years Undertake a massive business transformation by aligning change strategy with execution Solution: Consolidated Oracle Applications (E-Business Suite, Siebel, BI, Hyperion) and Oracle Fusion Middleware (AIA, SOA Suite) on Oracle Exalogic and Oracle ExadataBusiness Impact:Reduced financial and operating risk in re-architecting IT services to support new business capabilities supporting 87,000 manufacturersCompany: Ingersoll RandAbout: Leading manufacturer of industrial, climate, residential and security solutions.Challenges: Business continuity risks due to complexity in enforcing consistent operational and financial controls; Re-active business decisions reduced ability to offer differentiation and compete Solution: Consolidated Oracle E-business Suite on Oracle Exalogic and Oracle ExadataBusiness Impact:Service differentiation with faster order provisioning and a shorter lead-to-cash cycle translating into higher customer satisfaction and quicker cash-conversionCheck out the winners of the Oracle Fusion Middleware Innovation awards in other categories here.

    Read the article

  • Audio not working

    - by user3215
    Anybody could help me in troubleshooting audio problem on ubutnu 9.04 desktop edition?. For some reason I've to keep this os not upgraded and I'm trying to fix the audio problem on this for months. It works well on upgraded version(9.10,10.04) but not on jaunty. aplay -l: **** List of PLAYBACK Hardware Devices **** card 0: Intel [HDA Intel], device 0: ALC883 Analog [ALC883 Analog] Subdevices: 0/1 Subdevice #0: subdevice #0 card 0: Intel [HDA Intel], device 1: ALC883 Digital [ALC883 Digital] Subdevices: 1/1 Subdevice #0: subdevice #0 lsmod | grep snd: snd_hda_intel 436148 7 snd_pcm_oss 46336 0 snd_mixer_oss 22656 1 snd_pcm_oss snd_pcm 83076 4 snd_hda_intel,snd_pcm_oss snd_seq_dummy 10756 0 snd_seq_oss 37760 0 snd_seq_midi 14336 0 snd_rawmidi 29696 1 snd_seq_midi snd_seq_midi_event 15104 2 snd_seq_oss,snd_seq_midi snd_seq 56880 6 snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_seq_midi_event snd_timer 29704 2 snd_pcm,snd_seq snd_seq_device 14988 5 snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_rawmidi,snd_seq snd 62756 21 snd_hda_intel,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_seq_oss,snd_rawmidi,snd_seq,snd_timer,snd_seq_device soundcore 15200 1 snd snd_page_alloc 16904 2 snd_hda_intel,snd_pcm cat /proc/asound/cards: 0 [Intel ]: HDA-Intel - HDA Intel HDA Intel at 0xe1280000 irq 16 cat /proc/asound/version: Advanced Linux Sound Architecture Driver Version 1.0.18rc3. vim /etc/modules: # /etc/modules: kernel modules to load at boot time. # # This file contains the names of kernel modules that should be loaded # at boot time, one per line. Lines beginning with "#" are ignored. lp Audio Settings:

    Read the article

  • If not gamedev, what do I do !

    - by brainydexter
    Hi, I am a game dev who was working in the game-industry and then..got laid off. Ever since then, life couldn't get less stressful! During this time, I have met so many other devs who have also been laid off irrespective of the number of years they have been in the game. Now, the problem really gets worse, since I am not a US citizen (yes, I am in US) , and am on an international visa here, I might have to soon pack my bags and go back to my native country. Going back is not bad at all, apart from the fact, that gamedev is still in a very nascent stage there. There just aren't many opportunities. So, employment is the key to maintain a valid visa status. After giving it a lot of thought, I am thinking of staying away from gamedev jobs for the time being, given its job unstablity. This brings me to my current problem. I can't think of a domain/place where I can use my game development skills. I know graphics/simulation/visualization is huge, but I can't think straight and am left clueless where to go from here. What are some of the domains/companies where I can use my skills ? I'd appreciate any insight on this (and I apologize if this is not the place to post this kind of a question).

    Read the article

  • Guide to the web development ecosystem

    - by acjohnson55
    I'm a long-time software developer, and I've been thrown in the deep, deep end of developing from the ground up what will hopefully be a highly scalable and interactive web application. I've been out of the web game for about 8 years, and even when I was last in it, I wasn't exactly on the cutting edge. I think I've made judicious design decisions and I'm quite happy with the progress I've been making so far, but new, hot web technologies keep crawling out of the woodwork and into my headspace, forcing me to continually revalidate my implementation decisions. Complicating things even further is the preponderance of out-of-date information and the difficulty of knowing what is out of date in the first place. What I'm wondering is, are there any comprehensive books or guides dedicated to compiling and comparing the technologies out there, end-to-end in the web application stack? I'm happy to learn new techs on demand, but I don't like learning about them after I've already spent time going in another direction. I'm looking for the sort of executive info a CTO might read to make sure the best architectural decisions are being made. And just to be clear, this is a question about resources, not about specific technology suggestions.

    Read the article

  • Logging library for (c++) games

    - by Klaim
    I know a lot of logging libraries but didn't test a lot of them. (GoogleLog, Pantheios, the coming boost::log library...) In games, especially in remote multiplayer and multithreaded games, logging is vital to debugging, even if you remove all logs in the end. Let's say I'm making a PC game (not console) that needs logs (multiplayer and multithreaded and/or multiprocess) and I have good reasons for looking for a library for logging (like, I don't have time or I'm not confident in my ability to write one correctly for my case). Assuming that I need : performance ease of use (allow streaming or formating or something like that) reliable (don't leak or crash!) cross-platform (at least Windows, MacOSX, Linux/Ubuntu) Wich logging library would you recommand? Currently, I think that boost::log is the most flexible one (you can even log to remotely!), but have not good performance update: is for high performance, but isn't released yet. Pantheios is often cited but I don't have comparison points on performance and usage. I've used my own lib for a long time but I know it don't manage multithreading so it's a big problem, even if it's fast enough. Google Log seems interesting, I just need to test it but if you already have compared those libs and more, your advice might be of good use. Games are often performance demanding while complex to debug so it would be good to know logging libraries that, in our specific case, have clear advantages.

    Read the article

  • Caching WCF javascript proxy on browser

    - by oazabir
    When you use WCF services from Javascript, you have to generate the Javascript proxies by hitting the Service.svc/js. If you have five WCF services, then it means five javascripts to download. As browsers download javascripts synchronously, one after another, it adds latency to page load and slows down page rendering performance. Moreover, the same WCF service proxy is downloaded from every page, because the generated javascript file is not cached on browser. Here is a solution that will ensure the generated Javascript proxies are cached on browser and when there is a hit on the service, it will respond with HTTP 304 if the Service.svc file has not changed. Here’s a Fiddler trace of a page that uses two WCF services. You can see there are two /js hits and they are sequential. Every visit to the same page, even with the same browser session results in making those two hits to /js. Second time when the same page is browsed: You can see everything else is cached, except the WCF javascript proxies. They are never cached because the WCF javascript proxy generator does not produce the necessary caching headers to cache the files on browser. Here’s an HttpModule for IIS and IIS Express which will intercept calls to WCF service proxy. It first checks if the service is changed since the cached version on the browser. If it has not changed then it will return HTTP 304 and not go through the service proxy generation process. Thus it saves some CPU on server. But if the request is for the first time and there’s no cached copy on browser, it will deliver the proxy and also emit the proper cache headers to cache the response on browser. http://www.codeproject.com/Articles/360437/Caching-WCF-javascript-proxy-on-browser Don’t forget to vote.

    Read the article

  • Dynamically changing DVT Graph at Runtime

    - by mona.rakibe(at)oracle.com
    I recently came across this requirement where the customer wanted to change the graph type at run-time based on some selection. After some internal discussions we realized this can be best achieved by using af:switcher to toggle between multiple graphs. In this blog I will be sharing the sample that I build to demonstrate this.[Note] : In the below sample, every-time user changes graph type there is a server trip, so please use this approach with performance implications in mind.This sample can be downloaded  from DynamicGraph.zipSet-up: Create a BAM data control using employees DO (sample)(Refer this entry)Steps:Create the View Create a new JSF page .From component palette drag and drop "Select One Radio" into this page Enter some Label and click "Finish"In Property Editor set the "AutoSubmit" property to trueNow drag and drop "Switcher" from components into this page.In the Structure pane select the af:switcher right click and surround with "PanelGroupLayout"In Property Editor set the "PartialTriggers"  property of PanelGroupLayout to the id of af:selectOneRadioAgain in the Structure pane select the af:switcher right click and select "Insert inside af:switcher->facet"Enter Facet name (ex: pie)Again in the Structure pane select the af:switcher right click and select "Insert inside af:switcher->facet" Enter  another Facet name (ex: bar)From "Data Controls" drag and drop "Employees->Query"  into the pie facet as "Graph->Pie" (Pie: Sales_Number and Slices: Salesperson)From "Data Controls" drag and drop "Employees->Query"  into the bar facet as "Graph->Bar" (Bars :Sales_Number and X-axis : Salesperson).Now wire the switcher to the af:selectOneRadio using their "facetName" and "value" property respectively.Now run the page, notice that graph renders as per the selection by user.

    Read the article

  • Semi Fixed-timestep ported to javascript

    - by abernier
    In Gaffer's "Fix Your Timestep!" article, the author explains how to free your physics' loop from the paint one. Here is the final code, written in C: double t = 0.0; const double dt = 0.01; double currentTime = hires_time_in_seconds(); double accumulator = 0.0; State previous; State current; while ( !quit ) { double newTime = time(); double frameTime = newTime - currentTime; if ( frameTime > 0.25 ) frameTime = 0.25; // note: max frame time to avoid spiral of death currentTime = newTime; accumulator += frameTime; while ( accumulator >= dt ) { previousState = currentState; integrate( currentState, t, dt ); t += dt; accumulator -= dt; } const double alpha = accumulator / dt; State state = currentState*alpha + previousState * ( 1.0 - alpha ); render( state ); } I'm trying to implement this in JavaScript but I'm quite confused about the second while loop... Here is what I have for now (simplified): ... (function animLoop(){ ... while (accumulator >= dt) { // While? In a requestAnimation loop? Maybe if? ... } ... // render requestAnimationFrame(animLoop); // stand for the 1st while loop [OK] }()) As you can see, I'm not sure about the while loop inside the requestAnimation one... I thought replacing it with a if but I'm not sure it will be equivalent... Maybe some can help me.

    Read the article

  • Duck checker in Python: does one exist?

    - by elliot42
    Python uses duck-typing, rather than static type checking. But many of the same concerns ultimately apply: does an object have the desired methods and attributes? Do those attributes have valid, in-range values? Whether you're writing constraints in code, or writing test cases, or validating user input, or just debugging, inevitably somewhere you'll need to verify that an object is still in a proper state--that it still "looks like a duck" and "quacks like a duck." In statically typed languages you can simply declare "int x", and anytime you create or mutate x, it will always be a valid int. It seems feasible to decorate a Python object to ensure that it is valid under certain constraints, and that every time that object is mutated it is still valid under those constraints. Ideally there would be a simple declarative syntax to express "hasattr length and length is non-negative" (not in those words. Not unlike Rails validators, but less human-language and more programming-language). You could think of this as ad-hoc interface/type system, or you could think of it as an ever-present object-level unit test. Does such a library exist to declare and validate constraint/duck-checking on Python-objects? Is this an unreasonable tool to want? :) (Thanks!) Contrived example: rectangle = {'length': 5, 'width': 10} # We live in a fictional universe where multiplication is super expensive. # Therefore any time we multiply, we need to cache the results. def area(rect): if 'area' in rect: return rect['area'] rect['area'] = rect['length'] * rect['width'] return rect['area'] print area(rectangle) rectangle['length'] = 15 print area(rectangle) # compare expected vs. actual output! # imagine the same thing with object attributes rather than dictionary keys.

    Read the article

  • The Java Specialist: An Interview with Java Champion Heinz Kabutz

    - by Janice J. Heiss
    Dr. Heinz Kabutz is well known for his Java Specialists’ Newsletter, initiated in November 2000, where he displays his acute grasp of the intricacies of the Java platform for an estimated 70,000 readers; for his work as a consultant; and for his workshops and trainings at his home on the Island of Crete where he has lived since 2006 -- where he is known to curl up on the beach with his laptop to hack away, in between dips in the Mediterranean. Kabutz was born of German parents and raised in Cape Town, South Africa, where he developed a love of programming in junior high school through his explorations on a ZX Spectrum computer. He received a B.S. from the University of Cape Town, and at 25, a Ph.D., both in computer science. He will be leading a two-hour hands-on lab session, HOL6500 – “Finding and Solving Java Deadlocks,” at this year’s JavaOne that will explore what causes deadlocks and how to solve them. Q: Tell us about your JavaOne plans.A: I am arriving on Sunday evening and have just one hands-on-lab to do on Monday morning. This is the first time that a non-Oracle team is doing a HOL at JavaOne under Oracle's stewardship and we are all a bit nervous about how it will turn out. Oracle has been immensely helpful in getting us set up. I have a great team helping me: Kirk Pepperdine, Dario Laverde, Benjamin Evans and Martijn Verburg from jClarity, Nathan Reynolds from Oracle, Henri Tremblay of OCTO Technology and Jeff Genender of Savoir Technologies. Monday will be hard work, but after that, I will hopefully get to network with fellow Java experts, attend interesting sessions and just enjoy San Francisco. Oh, and my kids have already given me a shopping list of things to get, like a GoPro Hero 2 dive housing for shooting those nice videos of Crete. (That's me at the beginning diving down.) Q: What sessions are you attending that we should know about?A: Sometimes the most unusual sessions are the best. I avoid the "big names". They often are spread too thin with all their sessions, which makes it difficult for them to deliver what I would consider deep content. I also avoid entertainers who might be good at presenting but who do not say that much.In 2010, I attended a session by Vladimir Yaroslavskiy where he talked about sorting. Although he struggled to speak English, what he had to say was spectacular. There was hardly anybody in the room, having not heard of Vladimir before. To me that was the highlight of 2010. Funnily enough, he was supposed to speak with Joshua Bloch, but if you remember, Google cancelled. If Bloch has been there, the room would have been packed to capacity.Q: Give us an update on the Java Specialists’ Newsletter.A: The Java Specialists' Newsletter continues being read by an elite audience around the world. The apostrophe in the name is significant.  It is a newsletter for Java specialists. When I started it twelve years ago, I was trying to find non-obvious things in Java to write about. Things that would be interesting to an advanced audience.As an April Fool's joke, I told my readers in Issue 44 that subscribing would remain free, but that they would have to pay US$5 to US$7 depending on their geographical location. I received quite a few angry emails from that one. I would have not earned that much from unsubscriptions. Most readers stay for a very long time.After Oracle bought Sun, the Java community held its breath for about two years whilst Oracle was figuring out what to do with Java. For a while, we were quite concerned that there was not much progress shown by Oracle. My newsletter still continued, but it was quite difficult finding new things to write about. We have probably about 70,000 readers, which is quite a small number for a Java publication. However, our readers are the top in the Java industry. So I don't mind having "only" 70000 readers, as long as they are the top 0.7%.Java concurrency is a very important topic that programmers think they should know about, but often neglect to fully understand. I continued writing about that and made some interesting discoveries. For example, in Issue 165, I showed how we can get thread starvation with the ReadWriteLock. This was a bug in Java 5, which was corrected in Java 6, but perhaps a bit too much. Whereas we could get starvation of writers in Java 5, in Java 6 we could now get starvation of readers. All of these interesting findings make their way into my courseware to help companies avoid these pitfalls.Another interesting discovery was how polymorphism works in the Server HotSpot compiler in Issue 157 and Issue 158. HotSpot can inline methods from interfaces that have only one implementation class in the JVM. When a new subclass is instantiated and called for the first time, the JVM will undo the previous optimization and re-optimize differently.Here is a little memory puzzle for your readers: public class JavaMemoryPuzzle {  private final int dataSize =      (int) (Runtime.getRuntime().maxMemory() * 0.6);  public void f() {    {      byte[] data = new byte[dataSize];    }    byte[] data2 = new byte[dataSize];  }  public static void main(String[] args) {    JavaMemoryPuzzle jmp = new JavaMemoryPuzzle();    jmp.f();  }}When you run this you will always get an OutOfMemoryError, even though the local variable data is no longer visible outside of the code block.So here comes the puzzle, that I'd like you to ponder a bit. If you very politely ask the VM to release memory, then you don't get an OutOfMemoryError: public class JavaMemoryPuzzlePolite {  private final int dataSize =      (int) (Runtime.getRuntime().maxMemory() * 0.6);  public void f() {    {      byte[] data = new byte[dataSize];    }    for(int i=0; i<10; i++) {      System.out.println("Please be so kind and release memory");    }    byte[] data2 = new byte[dataSize];  }  public static void main(String[] args) {    JavaMemoryPuzzlePolite jmp = new JavaMemoryPuzzlePolite();    jmp.f();    System.out.println("No OutOfMemoryError");  }}Why does this work? When I published this in my newsletter, I received over 400 emails from excited readers around the world, most of whom sent me the wrong explanation. After the 300th wrong answer, my replies became unfortunately a bit curt. Have a look at Issue 174 for a detailed explanation, but before you do, put on your thinking caps and try to figure it out yourself. Q: What do you think Java developers should know that they currently do not know?A: They should definitely get to know more about concurrency. It is a tough subject that most programmers try to avoid. Unfortunately we do come in contact with it. And when we do, we need to know how to protect ourselves and how to solve tricky system errors.Knowing your IDE is also useful. Most IDEs have a ton of shortcuts, which can make you a lot more productive in moving code around. Another thing that is useful is being able to read GC logs. Kirk Pepperdine has a great talk at JavaOne that I can recommend if you want to learn more. It's this: CON5405 – “Are Your Garbage Collection Logs Speaking to You?” Q: What are you looking forward to in Java 8?A: I'm quite excited about lambdas, though I must confess that I have not studied them in detail yet. Maurice Naftalin's Lambda FAQ is quite a good start to document what you can do with them. I'm looking forward to finding all the interesting bugs that we will now get due to lambdas obscuring what is really going on underneath, just like we had with generics.I am quite impressed with what the team at Oracle did with OpenJDK's performance. A lot of the benchmarks now run faster.Hopefully Java 8 will come with JSR 310, the Date and Time API. It still boggles my mind that such an important API has been left out in the cold for so long.What I am not looking forward to is losing perm space. Even though some systems run out of perm space, at least the problem is contained and they usually manage to work around it. In most cases, this is due to a memory leak in that region of memory. Once they bundle perm space with the old generation, I predict that memory leaks in perm space will be harder to find. More contracts for us, but also more pain for our customers. Originally published on blogs.oracle.com/javaone.

    Read the article

  • The Java Specialist: An Interview with Java Champion Heinz Kabutz

    - by Janice J. Heiss
    Dr. Heinz Kabutz is well known for his Java Specialists’ Newsletter, initiated in November 2000, where he displays his acute grasp of the intricacies of the Java platform for an estimated 70,000 readers; for his work as a consultant; and for his workshops and trainings at his home on the Island of Crete where he has lived since 2006 -- where he is known to curl up on the beach with his laptop to hack away, in between dips in the Mediterranean. Kabutz was born of German parents and raised in Cape Town, South Africa, where he developed a love of programming in junior high school through his explorations on a ZX Spectrum computer. He received a B.S. from the University of Cape Town, and at 25, a Ph.D., both in computer science. He will be leading a two-hour hands-on lab session, HOL6500 – “Finding and Solving Java Deadlocks,” at this year’s JavaOne that will explore what causes deadlocks and how to solve them. Q: Tell us about your JavaOne plans.A: I am arriving on Sunday evening and have just one hands-on-lab to do on Monday morning. This is the first time that a non-Oracle team is doing a HOL at JavaOne under Oracle's stewardship and we are all a bit nervous about how it will turn out. Oracle has been immensely helpful in getting us set up. I have a great team helping me: Kirk Pepperdine, Dario Laverde, Benjamin Evans and Martijn Verburg from jClarity, Nathan Reynolds from Oracle, Henri Tremblay of OCTO Technology and Jeff Genender of Savoir Technologies. Monday will be hard work, but after that, I will hopefully get to network with fellow Java experts, attend interesting sessions and just enjoy San Francisco. Oh, and my kids have already given me a shopping list of things to get, like a GoPro Hero 2 dive housing for shooting those nice videos of Crete. (That's me at the beginning diving down.) Q: What sessions are you attending that we should know about?A: Sometimes the most unusual sessions are the best. I avoid the "big names". They often are spread too thin with all their sessions, which makes it difficult for them to deliver what I would consider deep content. I also avoid entertainers who might be good at presenting but who do not say that much.In 2010, I attended a session by Vladimir Yaroslavskiy where he talked about sorting. Although he struggled to speak English, what he had to say was spectacular. There was hardly anybody in the room, having not heard of Vladimir before. To me that was the highlight of 2010. Funnily enough, he was supposed to speak with Joshua Bloch, but if you remember, Google cancelled. If Bloch has been there, the room would have been packed to capacity.Q: Give us an update on the Java Specialists’ Newsletter.A: The Java Specialists' Newsletter continues being read by an elite audience around the world. The apostrophe in the name is significant.  It is a newsletter for Java specialists. When I started it twelve years ago, I was trying to find non-obvious things in Java to write about. Things that would be interesting to an advanced audience.As an April Fool's joke, I told my readers in Issue 44 that subscribing would remain free, but that they would have to pay US$5 to US$7 depending on their geographical location. I received quite a few angry emails from that one. I would have not earned that much from unsubscriptions. Most readers stay for a very long time.After Oracle bought Sun, the Java community held its breath for about two years whilst Oracle was figuring out what to do with Java. For a while, we were quite concerned that there was not much progress shown by Oracle. My newsletter still continued, but it was quite difficult finding new things to write about. We have probably about 70,000 readers, which is quite a small number for a Java publication. However, our readers are the top in the Java industry. So I don't mind having "only" 70000 readers, as long as they are the top 0.7%.Java concurrency is a very important topic that programmers think they should know about, but often neglect to fully understand. I continued writing about that and made some interesting discoveries. For example, in Issue 165, I showed how we can get thread starvation with the ReadWriteLock. This was a bug in Java 5, which was corrected in Java 6, but perhaps a bit too much. Whereas we could get starvation of writers in Java 5, in Java 6 we could now get starvation of readers. All of these interesting findings make their way into my courseware to help companies avoid these pitfalls.Another interesting discovery was how polymorphism works in the Server HotSpot compiler in Issue 157 and Issue 158. HotSpot can inline methods from interfaces that have only one implementation class in the JVM. When a new subclass is instantiated and called for the first time, the JVM will undo the previous optimization and re-optimize differently.Here is a little memory puzzle for your readers: public class JavaMemoryPuzzle {  private final int dataSize =      (int) (Runtime.getRuntime().maxMemory() * 0.6);  public void f() {    {      byte[] data = new byte[dataSize];    }    byte[] data2 = new byte[dataSize];  }  public static void main(String[] args) {    JavaMemoryPuzzle jmp = new JavaMemoryPuzzle();    jmp.f();  }}When you run this you will always get an OutOfMemoryError, even though the local variable data is no longer visible outside of the code block.So here comes the puzzle, that I'd like you to ponder a bit. If you very politely ask the VM to release memory, then you don't get an OutOfMemoryError: public class JavaMemoryPuzzlePolite {  private final int dataSize =      (int) (Runtime.getRuntime().maxMemory() * 0.6);  public void f() {    {      byte[] data = new byte[dataSize];    }    for(int i=0; i<10; i++) {      System.out.println("Please be so kind and release memory");    }    byte[] data2 = new byte[dataSize];  }  public static void main(String[] args) {    JavaMemoryPuzzlePolite jmp = new JavaMemoryPuzzlePolite();    jmp.f();    System.out.println("No OutOfMemoryError");  }}Why does this work? When I published this in my newsletter, I received over 400 emails from excited readers around the world, most of whom sent me the wrong explanation. After the 300th wrong answer, my replies became unfortunately a bit curt. Have a look at Issue 174 for a detailed explanation, but before you do, put on your thinking caps and try to figure it out yourself. Q: What do you think Java developers should know that they currently do not know?A: They should definitely get to know more about concurrency. It is a tough subject that most programmers try to avoid. Unfortunately we do come in contact with it. And when we do, we need to know how to protect ourselves and how to solve tricky system errors.Knowing your IDE is also useful. Most IDEs have a ton of shortcuts, which can make you a lot more productive in moving code around. Another thing that is useful is being able to read GC logs. Kirk Pepperdine has a great talk at JavaOne that I can recommend if you want to learn more. It's this: CON5405 – “Are Your Garbage Collection Logs Speaking to You?” Q: What are you looking forward to in Java 8?A: I'm quite excited about lambdas, though I must confess that I have not studied them in detail yet. Maurice Naftalin's Lambda FAQ is quite a good start to document what you can do with them. I'm looking forward to finding all the interesting bugs that we will now get due to lambdas obscuring what is really going on underneath, just like we had with generics.I am quite impressed with what the team at Oracle did with OpenJDK's performance. A lot of the benchmarks now run faster.Hopefully Java 8 will come with JSR 310, the Date and Time API. It still boggles my mind that such an important API has been left out in the cold for so long.What I am not looking forward to is losing perm space. Even though some systems run out of perm space, at least the problem is contained and they usually manage to work around it. In most cases, this is due to a memory leak in that region of memory. Once they bundle perm space with the old generation, I predict that memory leaks in perm space will be harder to find. More contracts for us, but also more pain for our customers.

    Read the article

  • How do I align my partition table properly?

    - by Jorge Castro
    I am in the process of building my first RAID5 array. I've used mdadm to create the following set up: root@bondigas:~# mdadm --detail /dev/md1 /dev/md1: Version : 00.90 Creation Time : Wed Oct 20 20:00:41 2010 Raid Level : raid5 Array Size : 5860543488 (5589.05 GiB 6001.20 GB) Used Dev Size : 1953514496 (1863.02 GiB 2000.40 GB) Raid Devices : 4 Total Devices : 4 Preferred Minor : 1 Persistence : Superblock is persistent Update Time : Wed Oct 20 20:13:48 2010 State : clean, degraded, recovering Active Devices : 3 Working Devices : 4 Failed Devices : 0 Spare Devices : 1 Layout : left-symmetric Chunk Size : 64K Rebuild Status : 1% complete UUID : f6dc829e:aa29b476:edd1ef19:85032322 (local to host bondigas) Events : 0.12 Number Major Minor RaidDevice State 0 8 16 0 active sync /dev/sdb 1 8 32 1 active sync /dev/sdc 2 8 48 2 active sync /dev/sdd 4 8 64 3 spare rebuilding /dev/sde While that's going I decided to format the beast with the following command: root@bondigas:~# mkfs.ext4 /dev/md1p1 mke2fs 1.41.11 (14-Mar-2010) /dev/md1p1 alignment is offset by 63488 bytes. This may result in very poor performance, (re)-partitioning suggested. Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=16 blocks, Stripe width=48 blocks 97853440 inodes, 391394047 blocks 19569702 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=0 11945 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, 102400000, 214990848 Writing inode tables: ^C 27/11945 root@bondigas:~# ^C I am unsure what to do about "/dev/md1p1 alignment is offset by 63488 bytes." and how to properly partition the disks to match so I can format it properly.

    Read the article

< Previous Page | 589 590 591 592 593 594 595 596 597 598 599 600  | Next Page >