Search Results

Search found 18576 results on 744 pages for 'lock screen'.

Page 63/744 | < Previous Page | 59 60 61 62 63 64 65 66 67 68 69 70  | Next Page >

  • [C#] Lock a file and avoid readings while it's writing

    - by vtortola
    Hi, My web application returns a file from the filesystem. These files are dynamic, so I have no way to know the names o how many of them will there be. When this file doesn't exist, the application creates it from the database. I want to avoid that two different threads recreate the same file at the same time, or that a thread try to return the file while other thread is creating it. So I want to lock a file till its recreation is complete, if other thread try to access it ... it will have to wait the file be unlocked. I've been reading about FileStream.Lock, but I have to know the file length and it won't prevent that other thread try to read the file, so it doesn't work for my particular case. I've been reading also about FileAccess.None, but it will throw an exception (which exception type?) if other thread/process try to access the file... so I should develop a "try again while is faulting" ... and I don't like too much that approach, although maybe there is not a better way. How could I archieve this? Kind regards.

    Read the article

  • How to Lock a file and avoid readings while it's writing

    - by vtortola
    My web application returns a file from the filesystem. These files are dynamic, so I have no way to know the names o how many of them will there be. When this file doesn't exist, the application creates it from the database. I want to avoid that two different threads recreate the same file at the same time, or that a thread try to return the file while other thread is creating it. So I want to lock a file till its recreation is complete, if other thread try to access it ... it will have to wait the file be unlocked. I've been reading about FileStream.Lock, but I have to know the file length and it won't prevent that other thread try to read the file, so it doesn't work for my particular case. I've been reading also about FileAccess.None, but it will throw an exception (which exception type?) if other thread/process try to access the file... so I should develop a "try again while is faulting" ... and I don't like too much that approach, although maybe there is not a better way.

    Read the article

  • Lucene.net create+lock errors in ASP.NET

    - by acidzombie24
    I have an issue with Lucene.net. It throws a lock exception. After poking around i notice these things. My code below works in an app bit when calling in Application_Start i get a NoSuchDirectoryException. Not closing the writer (as my code doesnt do below) i WILL get a LockObtainFailedException with the message Lock obtain timed out: SimpleFSLock@<FULL_PATH> from either app or asp.net These thread hinted when spawning threads they get less permissions then i do (but! my main thread has problems as well...) and one solution is to impersonate IIS. I am using visual studios 2010. I am not sure how full blown it is but my attempt to impersonate it failed. So my question is how do i have lucene create the directory and not throw an exception if dont close the writer for some reason (such as power going out)? http://stackoverflow.com/questions/2341163/why-is-my-lucene-index-getting-locked/2499285#2499285 http://stackoverflow.com/questions/1123517/lucene-net-and-i-o-threading-issue/1123981#1123981 static IndexWriter writer = null; static void lucene_init() { bool create = false; //I now use a full path. I still get NoSuchDirectoryException //string dirname = "LuceneIndex_z"; if (System.IO.Directory.Exists(dirname) == false) create = true; var directory = FSDirectory.GetDirectory(dirname); var analyzer = new StandardAnalyzer(); writer = new IndexWriter(directory, analyzer, create); }

    Read the article

  • Lucene.net create+lock errors in ASP.NET

    - by acidzombie24
    I have an issue with Lucene.net. It throws a lock exception. After poking around i notice these things. My code below works in an app bit when calling in Application_Start i get a NoSuchDirectoryException. Not closing the writer (as my code doesnt do below) i WILL get a LockObtainFailedException with the message Lock obtain timed out: SimpleFSLock@<FULL_PATH> from either app or asp.net These thread hinted when spawning threads they get less permissions then i do (but! my main thread has problems as well...) and one solution is to impersonate IIS. I am using visual studios 2010. I am not sure how full blown it is but my attempt to impersonate it failed. So my question is how do i have lucene create the directory and not throw an exception if dont close the writer for some reason (such as power going out)? http://stackoverflow.com/questions/2341163/why-is-my-lucene-index-getting-locked/2499285#2499285 http://stackoverflow.com/questions/1123517/lucene-net-and-i-o-threading-issue/1123981#1123981 static IndexWriter writer = null; static void lucene_init() { bool create = false; string dirname = "LuceneIndex_z"; if (System.IO.Directory.Exists(dirname) == false) create = true; var directory = FSDirectory.GetDirectory(dirname); var analyzer = new StandardAnalyzer(); writer = new IndexWriter(directory, analyzer, create); }

    Read the article

  • OpenGL Calls Lock/Freeze

    - by Necrolis
    I am using some dell workstations(running WinXP Pro SP 2 & DeepFreeze) for development, but something was recenlty loaded onto these machines that prevents any opengl call(the call locks) from completing(and I know the code works as I have tested it on 'clean' machines, I also tested with simple opengl apps generated by dev-cpp, which will also lock on the dell machines). I have tried to debug my own apps to see where exactly the gl calls freeze, but there is some global system hook on ZwQueryInformationProcess that messes up calls to ZwQueryInformationThread(used by ExitThread), preventing me from debugging at all(it causes the debugger, OllyDBG, to go into an access violation reporting loop or the program to crash if the exception is passed along). the hook: ntdll.ZwQueryInformationProcess 7C90D7E0 B8 9A000000 MOV EAX,9A 7C90D7E5 BA 0003FE7F MOV EDX,7FFE0300 7C90D7EA FF12 CALL DWORD PTR DS:[EDX] 7C90D7EC - E9 0F28448D JMP 09D50000 7C90D7F1 9B WAIT 7C90D7F2 0000 ADD BYTE PTR DS:[EAX],AL 7C90D7F4 00BA 0003FE7F ADD BYTE PTR DS:[EDX+7FFE0300],BH 7C90D7FA FF12 CALL DWORD PTR DS:[EDX] 7C90D7FC C2 1400 RETN 14 7C90D7FF 90 NOP ntdll.ZwQueryInformationToken 7C90D800 B8 9C000000 MOV EAX,9C the messed up function + call: ntdll.ZwQueryInformationThread 7C90D7F0 8D9B 000000BA LEA EBX,DWORD PTR DS:[EBX+BA000000] 7C90D7F6 0003 ADD BYTE PTR DS:[EBX],AL 7C90D7F8 FE ??? ; Unknown command 7C90D7F9 7F FF JG SHORT ntdll.7C90D7FA 7C90D7FB 12C2 ADC AL,DL 7C90D7FD 14 00 ADC AL,0 7C90D7FF 90 NOP ntdll.ZwQueryInformationToken 7C90D800 B8 9C000000 MOV EAX,9C So firstly, anyone know what if anything would lead to OpenGL calls cause an infinite lock,and if there are any ways around it? and what would be creating such a hook in kernal memory ? Update: After some more fiddling, I have discovered a few more kernal hooks, a lot of them are used to nullify data returned by system information calls(such as the remote debugging port), I also managed to find out the what ever is doing this is using madchook.dll(by madshi) to do this, this dll is also injected into every running process(these seem to be some anti debugging code). Also, on the OpenGL side, it seems Direct X is fine/unaffected(I ran one of the DX 9 demo's without problems), so could one of these kernal hooks somehow affect OpenGL?

    Read the article

  • Using SQL dB column as a lock for concurrent operations in Entity Framework

    - by Sid
    We have a long running user operation that is handled by a pool of worker processes. Data input and output is from Azure SQL. The master Azure SQL table structure columns are approximated to [UserId, col1, col2, ... , col N, beingProcessed, lastTimeProcessed ] beingProcessed is boolean and lastTimeProcessed is DateTime. The logic in every worker role is: public void WorkerRoleMain() { while(true) { try { dbContext db = new dbContext(); // Read foreach (UserProfile user in db.UserProfile .Where(u => DateTime.UtcNow.Subtract(u.lastTimeProcessed) > TimeSpan.FromHours(24) & u.beingProcessed == false)) { user.beingProcessed = true; // Modify db.SaveChanges(); // Write // Do some long drawn processing here ... ... ... user.lastTimeProcessed = DateTime.UtcNow; user.beingProcessed = false; db.SaveChanges(); } } catch(Exception ex) { LogException(ex); Sleep(TimeSpan.FromMinutes(5)); } } // while () } With multiple workers processing as above (each with their own Entity Framework layer), in essence beingProcessed is being used a lock for MutEx purposes Question: How can I deal with concurrency issues on the beingProcessed "lock" itself based on the above load? I think read-modify-write operation on the beingProcessed needs to be atomic but I'm open to other strategies. Open to other code refinements too.

    Read the article

  • JDBC transaction dead-lock solution required?

    - by user49767
    It's a scenario described my friend and challenged to find solution. He is using Oracle database and JDBC connection with read committed as transaction isolation level. In one of the transaction, he updates a record and executes selects statement and commits the transaction. when everything happening within single thread, things are fine. But when multiple requests are handled, dead-lock happens. Thread-A updates a record. Thread B updates another record. Thread-A issues select statement and waits for Thread-B's transaction to complete the commit operation. Thread-B issues select statement and waits for Thread-A's transaction to complete the commit operation. Now above causes dead-lock. Since they use command pattern, the base framework allows to issue commit only once (at the end of all the db operation), so they are unable to issue commit immediately after select statement. My argument was Thread-A supposed to select all the records which are committed and hence should not be issue. But he said that Thread-A will surely wait till Thread-B commits the record. is that true? What are all the ways, to avoid the above issue? is it possible to change isolation-level? (without changing underlying java framework) Little information about base framework, it is something similar to Struts action, their each and every request handled by one action, transaction begins before execution and commits after execution.

    Read the article

  • MFC/CCriticalSection: Simple lock situation hangs

    - by raph.amiard
    I have to program a simple threaded program with MFC/C++ for a uni assignment. I have a simple scenario in wich i have a worked thread which executes a function along the lines of : UINT createSchedules(LPVOID param) { genProgThreadVal* v = (genProgThreadVal*) param; // v->searcherLock is of type CcriticalSection* while(1) { if(v->searcherLock->Lock()) { //do the stuff, access shared object , exit clause etc.. v->searcherLock->Unlock(); } } PostMessage(v->hwnd, WM_USER_THREAD_FINISHED , 0,0); delete v; return 0; } In my main UI class, i have a CListControl that i want to be able to access the shared object (of type std::List). Hence the locking stuff. So this CList has an handler function looking like this : void Ccreationprogramme::OnLvnItemchangedList5(NMHDR *pNMHDR, LRESULT *pResult) { LPNMLISTVIEW pNMLV = reinterpret_cast<LPNMLISTVIEW>(pNMHDR); if((pNMLV->uChanged & LVIF_STATE) && (pNMLV->uNewState & LVNI_SELECTED)) { searcherLock.Lock(); // do the stuff on shared object searcherLock.Unlock(); // do some more stuff } *pResult = 0; } The searcherLock in both function is the same object. The worker thread function is passed a pointer to the CCriticalSection object, which is a member of my dialog class. Everything works but, as soon as i do click on my list, and so triggers the handler function, the whole program hangs indefinitely.I tried using a Cmutex. I tried using a CSingleLock wrapping over the critical section object, and none of this has worked. What am i missing ?

    Read the article

  • Rails Heroku Gemfile.lock error - push rejected (open source)

    - by KJ50
    I am trying to push my open source RoR application to Heroku but I'm having an issue making the initial push. I have read many similar questions, but none of those answers has helped to solve my problem. I have tried bundle update and bundle install various times. I also have tried removing and then re-committing my Gemfile.lock file, however I get this same error still... $ git push heroku master Counting objects: 5199, done. Compressing objects: 100% (3086/3086), done. Writing objects: 100% (5199/5199), 4.57 MiB | 131 KiB/s, done. Total 5199 (delta 3418), reused 3152 (delta 1962) -----> Removing .DS_Store files -----> Ruby app detected -----> Compiling Ruby/NoLockfile ! ! Gemfile.lock required. Please check it in. ! ! Push rejected, failed to compile Ruby app To [email protected]:frozen-springs-4725.git ! [remote rejected] master -> master (pre-receive hook declined) error: failed to push some refs to '[email protected]:frozen-springs-4725.git' Since my application uses MongoDB with MongoMapper, I suspect that I have some configuration incorrect. My code can be found here on Github (I'm currently working on the heroku branch). Feel free to clone our repository and try it yourself. If anyone has any insight which could help me resolve this issue I would be very thankful!

    Read the article

  • How to fix Ubuntu 12.04.3 boot to black screen full of errors in white text, after upgrading on dell inspiron 1501

    - by Ibuntu
    I am running a Dell Inspiron 1501 I use Linux only. No Microsoft or Apple operating systems (or really anything closed-source). I've only been using Linux for a little over a year but I'm starting to gain a comfortable level of familiarity with the system and terminology. I've been having some issues with Quantel Quetzal and Raring Ringtail, especially with older hardware, so I opted to install Ubuntu 12.04.3 Precise Pangolin on the Inspiron 1501. I checked my MD5 sum after downloading my ISO and all was good. I have in fact used this iso/dvd to install Precise Pangolin successfully on a few other systems (some of which are even older than this laptop). Install goes fine. The wireless card doesn't work out of the box but this is a known issue which is fairly easy to fix. So, first thing I did was open up a terminal and run sudo apt-get update && sudo apt-get upgrade which, part way through, crashed (I assume lightdm and possibly X) and took me to a black screen filled with white lines of text that were either errors or just the ouputs of commands. The reason I say that is because I was unable to gleam any useful information from the output on the screen. I did take a picture however and will post a link. After that, every time I boot the system it goes right to that black screen posting all the error messages or output in white text. I never get a purple Ubuntu splash, so from what I can tell after reading this wiki article: https://wiki.ubuntu.com/X/Troubleshooting/BlankScreen That means that after the kernel is selected, it is unable to correctly implement the settings it needs. If the purple splash never shows, the frame buffer was never set correctly right? This leads me to believe that it could be a kernel issue? The wiki suggested to try and pinpoint the issue by rolling back kernels until I find one that works. Is this my best option? I think I'm going to give it a try anyways and will let everyone know if I am able to solve the issue this way. I have since done a few reinstalls and some trouble-shooting including a couple hours scouring the net for anyone with any kind of similar issue. Most of the issues I could find involved getting a black screen after login and none of them said anything about any information output on this black screen. My reinstalls have taught me that there is no issue updating, but as soon as I run sudo apt-get upgrade my system goes to the black screen and every time I boot it up it does the same thing. The only way to fix is by reinstall. I never get any ability to log in. After a hard power off to the laptop (because I cannot use ctrl+alt+del to reboot) when it boots again it goes to the grub boot menu and I can select between regular boot, recovery mode and the two memtest options. I never tried the memtest options but the other two both lead to the same black screen. Some people having a black/blank screen issue claim to have fixed it by using 12.10 or 13.04 but I believe they were having a different issue where they got a black/blank screen after logging in. I think I will still give these images a try, but mostly figured I would just wait another day or two for 13.10. Other things I figured I would try from the following three articles: After logging in, there's a black screen and my cursor, nothing else! in Ubuntu 12.10 Black Screen on Login After Upgrading to 12.04 I can't get to the login screen include opening a terminal using ctrl+alt+f1 and trying a variety of reseting unity, x settings, lightdm (or switching to gdm); but I doubt this will work or that I will even be able to access a terminal. I'm pretty sure the whole system is stuck after it loads the last line on the black screen. I will try these things and post more information when I have. Hopefully someone has an idea in the meantime and I will keep checking back trying to find a solution. Thank you. Here are 3 different pictures of the error message. I had to take with my phone: http://ubuntuone.com/album/0TBBkxmVajJIQQtoN9mVdN

    Read the article

  • Fast screen capture and lost Vsync

    - by user338759
    Hi, I'd like to generate a movie in real time with a self-made application doing fast screen captures with part of the screen occupied by a running 3D application. I'm aware that several applications already exist for this (like FRAPS or Taksi), and even dedicated DirectShow filters (like UScreenCapture), but i really need to make this with my own external application. When correctly setup (UScreenCapture + ffdshow), capturing an compressing a full screen does not consumes as much CPU as you would expect (about 15%), and does not impairs the performances of the 3D app. The problem of doing a capture from an external application is that the 3D application loses it's Vsync and creates a shaggy, difficult to use 3D application (3D app is only presented on a small part of the screen, the rest being GDI, DirectX) FRAPS solves this problem by allowing you to capture only one application at a time (the one with focus). Depending on the technology used (OpenGl, DirectX, GDI), it hooks the Vsync and does its capture (with glReadPixels,...), without perturbing it. Doing this does not solve my problem, since I want the full composed screen image (including 3D and the rest) AND a smooth 3D app. The UScreenCapture seems to use a fast DirectX call to capture the whole screen, but the openGL 3D app is still out of sync. Doing a BitBlt is too slow and CPU consumming to do real time 30 fps acquisition (at least under windows XP, not sure with 7) My question is to know if there is a way to achieve my goal with Windows 7 and it's brand new DirectX compositing engine? Windows 7 succeeds to show live VSynced duplicated previews of every app (in the taskbar), so there must be a way to access the currenlty displayed screen buffer without perturbing the rendering of the 3D OpenGL app ? Any other suggestion, technology ? thank you

    Read the article

  • Which alt text is best for screen readers for example "smiling kid"?

    - by jitendra
    Which would be good write ALT text for a photo of kid which is smiling and sitting in garden? This alt="Photo of smiling kid sitting in the garden" or this alt="Photo of smiling kid" or this alt="Smiling kid sitting in the garden" or this alt="Smiling kid" my purpose is to ask this question, I want to know should we include "Photo of..." in every alt text and And how much we should describe the photo in alt text.

    Read the article

  • How my Website looks like under Different Screen Resolutions?

    - by strakastroukas
    Back in the past, i found a third party webpage that was able to capture and save images of my website in different resolutions and browsers. Of course i have no more that bookmark... So is there any webpage or application where i can see how my webpage looks like in different resolution? And here are the resolutions i would like to check for... 1. 1024x768 24.56% 2. 1280x800 22.06% 3. 1280x1024 13.42% 4. 1366x768 7.10% 5. 1440x900 6.68%

    Read the article

  • How to use regular expressions to pull a substring? (screen scraping)

    - by Diego
    Hey guys, i'm really trying to understand regular expressions while scraping a site, i've been using it in my code enough to pull the following, but am stuck here. I need to quickly grab this: http://www.example.com/online/store/TitleDetail?detail&sku=123456789 from this: ('<a href="javascript:if(handleDoubleClick(this.id)){window.location=\'http://www.example.com/online/store/TitleDetail?detail&sku=123456789\';}" id="getTitleDetails_123456789">\r\n\t\t\t \tcheck store inventory\r\n\t\t\t </a>', 1) This is where I got confused. any ideas?

    Read the article

  • Stretch VMWare Player guest OS to fullscreen

    - by Synetech
    I’m using VMWare Player to play an old 16-bit Windows game. Unfortunately the game uses only 640x480 and I cannot figure out how to stretch the VM window to full-screen on the host. I set the guest OS to 640x480, but the screen is still small, in the middle of the screen as seen in figure 1. I even tried setting the compatibility mode to Windows 95 and 640x480, but it has no effect (figure 2) and looks exactly the same as when I set the VM to full-screen (1366x768 on the laptop) and start the game normally. There are few references to stretching a VM. One page mentions setting a Stretch Guest option, but there is no such option, at least not in VMWare Player 4.0.3. I know that VirtualBox has a stretching option, but I’m trying to find a solution for VMWare (Player, not Workstation). Figure 1: Guest OS is pillar-boxed Figure 2: Using compatibility mode

    Read the article

  • Flash Displays Black Screen No Video YouTube Firefox 11

    - by fleamour
    The title says it all, Flash Aid has not helped the situation & Google has not thrown up any recent similarities. I am running Xubuntu LTS. about:plugins ~ File: libflashplayer.so Version: Shockwave Flash 11.2 r202 ii flashplugin-installer 11.2.202.228ubuntu0.10.04.1 Adobe Flash Player plugin installer ii libswfdec-0.8-0 0.8.4-1build1 SWF (Macromedia Flash) decoder library ii swfdec-mozilla 0.8.2-1ubuntu2 Mozilla plugin for SWF files (Macromedia Flash)

    Read the article

  • Anthony Lye Shows New Pharmaceutical Sales Solution: Turn the Screen Around

    - by charles.knapp
    Tomorrow, March 31, watch as senior vice president of CRM, Anthony Lye, and director of life sciences product strategy, Piers Evans, provide the first public look at Oracle's new Pharmaceutical Sales solution, powered by Oracle CRM On Demand 17 - Life Sciences Edition. You will see a next generation approach to sell more and report less. Register now for this informative global webcast on March 31, 9 AM PDT/4 PM GMT.

    Read the article

  • How to troubleshoot web server lock-up (Debian Squeeze)

    - by Ryan
    Every once in a while, my web server slows so significantly, it seems locked up. Can't SSH in, no sites being served. It's a VPS that started out as Debian 5 which I upgraded to testing (squeeze). It's a typical LAMP set-up with the sole purpose of running a couple of wordpress sites. One time when it locked up, I got to one of the sites, but it was wordpress complaining it couldn't establish a database connection. So it seemed as if something was really chewing up the CPU and mysqld either timed out, or possibly failed and couldn't restart. But since I couldn't SSH in I feel more inclined to attribute it to CPU. But the only processes running now, aside from OS and kernel stuff: apache mysqld python (for fail2ban) sshd exim4 It has 512M of RAM and 1.5 GB of swap. Every time I check on it, it has plenty of free memory and is using virtually no swap (usually 2-3M). And since I am running fail2ban I don't think I'm getting ddosed. I did find this in my logwatch email this morning (it locked up late last night, when there would have been very little traffic): 6 Time(s): [<ffffffff810a0ebc>] ? oom_kill_process+0x7e/0x23d 6 Time(s): [<ffffffff810a1505>] ? __out_of_memory+0x12a/0x141 6 Time(s): [<ffffffff810a1586>] ? out_of_memory+0x6a/0x94 I didn't find anything else suspicious. It can't be my provider's host because I can SSH in and restart the VM, and everything seems fine. Anybody know which logs I should start poring through to find the core of my problem? Thanks guys.

    Read the article

  • How do I create a popup banner before login with Lightdm?

    - by Rich Loring
    When Ubuntu was using gnome I was able to create a popup banner like the banner below before the login screen using zenity in the /etc/gdm/Init/Default. The line of code would be like this: if [ -f "/usr/bin/zenity" ]; then /usr/bin/zenity --info --text="`cat /etc/issue`" --no-wrap; else xmessage -file /etc/issue -button ok -geometry 540X480; fi How can I accomplish this with Unity? NOTICE TO USERS This is a Federal computer system (and/or it is directly connected to a BNL local network system) and is the property of the United States Government. It is for authorized use only. Users (authorized or unauthorized) have no explicit or implicit expectation of privacy. Any or all uses of this system and all files on this system may be intercepted, monitored, recorded, copied, audited, inspected, and disclosed to authorized site, Department of Energy, and law enforcement personnel, as well as authorized officials of other agencies, both domestic and foreign. By using this system, the user consents to such interception, monitoring, recording, copying, auditing, inspection, and disclosure at the discretion of authorized site or Department of Energy personnel. Unauthorized or improper use of this system may result in administrative disciplinary action and civil and criminal penalties. By continuing to use this system you indicate your awareness of and consent to these terms and conditions of use. LOG OFF IMMEDIATELY if you do not agree to the conditions stated in this warning.

    Read the article

< Previous Page | 59 60 61 62 63 64 65 66 67 68 69 70  | Next Page >