Search Results

Search found 9705 results on 389 pages for 'boost thread'.

Page 25/389 | < Previous Page | 21 22 23 24 25 26 27 28 29 30 31 32  | Next Page >

  • .net thread safety

    - by george9170
    Why is locking a type considered very bad? For example, lock(typeof(DateTime)) I understand that static methods of any class in .net is considered thread safe, and that instance members are not. So it isn't necessary to lock DateTime while you are using it. The book I am reading doesn't explain why it is bad it just says it is. Any explanation will be great.

    Read the article

  • Simple thread-safe non-blocking file logger class in c#

    - by Jason Renlan
    I have a web application, that will log some information to a file. I am looking for a simple thread-safe non-blocking file logger class in c#. I have little experience with threading. I known there are great logging components out there like log4Net, Enterprise Library Logging Block, ELMAH, but I do not want an external dependence for my application. I was thinking about using this queue implementation http://www.codeproject.com/KB/cpp/lockfreeq.aspx

    Read the article

  • May volatile be in user defined types to help writing thread-safe code

    - by David Rodríguez - dribeas
    I know, it has been made quite clear in a couple of questions/answers before, that volatile is related to the visible state of the c++ memory model and not to multithreading. On the other hand, this article by Alexandrescu uses the volatile keyword not as a runtime feature but rather as a compile time check to force the compiler into failing to accept code that could be not thread safe. In the article the keyword is used more like a required_thread_safety tag than the actual intended use of volatile. Is this (ab)use of volatile appropriate? What possible gotchas may be hidden in the approach? The first thing that comes to mind is added confusion: volatile is not related to thread safety, but by lack of a better tool I could accept it. Basic simplification of the article: If you declare a variable volatile, only volatile member methods can be called on it, so the compiler will block calling code to other methods. Declaring an std::vector instance as volatile will block all uses of the class. Adding a wrapper in the shape of a locking pointer that performs a const_cast to release the volatile requirement, any access through the locking pointer will be allowed. Stealing from the article: template <typename T> class LockingPtr { public: // Constructors/destructors LockingPtr(volatile T& obj, Mutex& mtx) : pObj_(const_cast<T*>(&obj)), pMtx_(&mtx) { mtx.Lock(); } ~LockingPtr() { pMtx_->Unlock(); } // Pointer behavior T& operator*() { return *pObj_; } T* operator->() { return pObj_; } private: T* pObj_; Mutex* pMtx_; LockingPtr(const LockingPtr&); LockingPtr& operator=(const LockingPtr&); }; class SyncBuf { public: void Thread1() { LockingPtr<BufT> lpBuf(buffer_, mtx_); BufT::iterator i = lpBuf->begin(); for (; i != lpBuf->end(); ++i) { // ... use *i ... } } void Thread2(); private: typedef vector<char> BufT; volatile BufT buffer_; Mutex mtx_; // controls access to buffer_ };

    Read the article

  • Linux's thread local storage implementation

    - by anon
    __thread Foo foo; How is "foo" actually resolved? Does the compiler silently replace every instance of "foo" with a function call? Is "foo" stored somewhere relative to the bottom of the stack, and the compiler stores this as "hey, for each thread, have this space near the bottom of the stack, and foo is stored as 'offset x from bottom of stack'"?

    Read the article

  • Fast inter-thread communication mechanism

    - by Stan
    I need a fast inter-thread communication mechanism for passing work (void*) from TBB tasks to several workers which are running blocking operations. Currently I'm looking into using pipe()+libevent. Is there a faster and more elegant alternative for use with Intel Threading Building Blocks?

    Read the article

  • How do I write a analyzable thread dump format

    - by gamue
    I'm creating a global exception handling which collects some information before shutting down in some cases. One of this information is the current thread dump. i do this with following code: ManagementFactory.getThreadMXBean().dumpAllThreads(true, true); The problem is to write the information into a analyzable format for TDA. Is there a "simple" way to format the information instead of writing the format on my own?

    Read the article

  • How to debug hanging main thread in Delphi application

    - by Harriv
    Hi, I've written application in Delphi 2007, which some times hangs (not even every week, application is running 24/7). It looks like main thread gets stuck. What are the options to pinpoint the cause for this problem? Application is written in Delphi 2007, it uses RemObjects, DBExpress with Firebird, OPC communication using COM.

    Read the article

  • C# event handlers not thread safe?

    - by Daniel
    So i've read around that instead of calling a event directly with if (SomeEvent != null) SomeEvent(this, null); i should be doing SomeEventHandler temp = SomeEvent; if (temp != null) temp(this, null); Why is this so? How does the second version become thread safe? What is the best practice?

    Read the article

  • Java: thread-safe RandomAccessFile

    - by Folkert van Heusden
    Hi, After some serious googleing I found out that the RandomAccessFile-class is not thread-safe. Now I could use one semaphore to lock all reads and writes but I don't think that performs very well. In theory it should be possible to do multiple reads and one write at a time. How can I do this in Java? Is it possible at all? Thanks!

    Read the article

  • Run a form in another thread

    - by Smith
    i have five forms in my c# project. one host an httplistener that i want to run continionsly. when the listener gets a message, it passes it to a static class, which in turn calls the appropriate forms for another processing. is it possible that the static class calls the new form in a new thread? if so please help me out

    Read the article

  • C++ Thread level constants

    - by Gokul
    Is there a way by which we can simulate thread level constants in C++? For example, if i have to make a call to template functions, then i need to mention the constants as template level parameters? I can use static const variables for template metaprogramming, but they are process level constants. I know, i am asking a question with a high probability of 'No'. Just thought of asking this to capitalize on the very rare probability :)) Thanks, Gokul.

    Read the article

  • Thread safety in C# arrays

    - by Betamoo
    Does having 2 different threads : one reading from a C# array (e.g from first location), and another one writing to the same C# array but to a different location(e.g to the last location) is thread safe or not? (And I mean here without locking reading nor writing)

    Read the article

  • Problem with thread after SCREEN_OFF in Android

    - by michael
    I’m doing an application that listens to the android.intent.action.SCREEN_OFF in a Service (if that matter) and then it is supposed to wait a few seconds and launch an action, I’ve tried a timer schedule method, thread and handler postDelay method but all of them seems to fail, they are never executed on a device, it seems like it’s being freezed/killed after phone is locked. It works on emulator and on device attached to USB, but never with device working on battery only, which actually is a main scenario. Do you know any solutions to this?

    Read the article

  • Long running calculation on background thread

    - by SundayMonday
    In my Cocos2D game for iOS I have a relatively long running calculation that happens at a fairly regular interval (every 1-2 seconds). I'd like to run the calculation on a background thread so the main thread can keep the animation smooth. The calculation is done on a grid. Average grid size is about 100x100 where each cell stores an integer. Should I copy this grid when I pass it to the background thread? Or can I pass a reference and just make sure I don't write to the grid from the main thread before the background thread is done? Copying seems a bit wasteful but passing a reference seems risky. So I thought I'd ask.

    Read the article

  • Java - Call to start method on thread : how does it route to Runnable interface's run () ?

    - by Bhaskar
    Ok , I know the two standard ways to create a new thread and run it in Java : 1 Implement Runnable in a class , define run method ,and pass an instance of the class to a new Thread. When the start method on the thread instance is called , the run method of the class instance will be invoked. 2 Let the class derive from Thread, so it can to override the method run() and then when a new instance's start method is called , the call is routed to overridden method. In both methods , basically a new Thread object is created and its start method invoked. However , while in the second method , the mechanism of the call being routed to the user defined run() method is very clear ,( its a simple runtime polymorphism in play ), I dont understand how the call to start method on the Thread object gets routed to run() method of the class implementing Runnable interface. Does the Thread class have an private field of Type Runnable which it checks first , and if it is set then invokes the run method if it set to an object ? that would be a strange mechanism IMO. How does the call to start() on a thread get routed to the run method of the Runnable interface implemented by the class whose object is passed as a parameter when contructing the thread ?

    Read the article

  • C++ volatile required when spinning on boost::shared_ptr operator bool()?

    - by JaredC
    I have two threads referencing the same boost::shared_ptr: boost::shared_ptr<Widget> shared; On thread is spinning, waiting for the other thread to reset the boost::shared_ptr: while(shared) boost::thread::yield(); And at some point the other thread will call: shared.reset(); My question is whether or not I need to declare the shared pointer as volatile to prevent the compiler from optimizing the call to shared.operator bool() out of the loop and never detecting the change? I know that if I were simply looping on a variable, waiting for it to reach 0 I would need volatile, but I'm not sure if boost::shared_ptr is implemented in such a way that it is not necessary here.

    Read the article

  • Windows Form hangs when running threads

    - by Benjamin Ortuzar
    JI have written a .NET C# Windows Form app in Visual Studio 2008 that uses a Semaphore to run multiple jobs as threads when the Start button is pressed. It’s experiencing an issue where the Form goes into a comma after being run for 40 minutes or more. The log files indicate that the current jobs complete, it picks a new job from the list, and there it hangs. I have noticed that the Windows Form becomes unresponsive when this happens. The form is running in its own thread. This is a sample of the code I am using: protected void ProcessJobsWithStatus (Status status) { int maxJobThreads = Convert.ToInt32(ConfigurationManager.AppSettings["MaxJobThreads"]); Semaphore semaphore = new Semaphore(maxJobThreads, maxJobThreads); // Available=3; Capacity=3 int threadTimeOut = Convert.ToInt32(ConfigurationManager.AppSettings["ThreadSemaphoreWait"]);//in Seconds //gets a list of jobs from a DB Query. List<Job> jobList = jobQueue.GetJobsWithStatus(status); //we need to create a list of threads to check if they all have stopped. List<Thread> threadList = new List<Thread>(); if (jobList.Count > 0) { foreach (Job job in jobList) { logger.DebugFormat("Waiting green light for JobId: [{0}]", job.JobId.ToString()); if (!semaphore.WaitOne(threadTimeOut * 1000)) { logger.ErrorFormat("Semaphore Timeout. A thread did NOT complete in time[{0} seconds]. JobId: [{1}] will start", threadTimeOut, job.JobId.ToString()); } logger.DebugFormat("Acquired green light for JobId: [{0}]", job.JobId.ToString()); // Only N threads can get here at once job.semaphore = semaphore; ThreadStart threadStart = new ThreadStart(job.Process); Thread thread = new Thread(threadStart); thread.Name = job.JobId.ToString(); threadList.Add(thread); thread.Start(); } logger.Info("Waiting for all threads to complete"); //check that all threads have completed. foreach (Thread thread in threadList) { logger.DebugFormat("About to join thread(jobId): {0}", thread.Name); if (!thread.Join(threadTimeOut * 1000)) { logger.ErrorFormat("Thread did NOT complete in time[{0} seconds]. JobId: [{1}]", threadTimeOut, thread.Name); } else { logger.DebugFormat("Thread did complete in time. JobId: [{0}]", thread.Name); } } } logger.InfoFormat("Finished Processing Jobs in Queue with status [{0}]...", status); } //form methods private void button1_Click(object sender, EventArgs e) { buttonStop.Enabled = true; buttonStart.Enabled = false; ThreadStart threadStart = new ThreadStart(DoWork); workerThread = new Thread(threadStart); serviceStarted = true; workerThread.Start(); } private void DoWork() { EmailAlert emailAlert = new EmailAlert (); // start an endless loop; loop will abort only when "serviceStarted" flag = false while (serviceStarted) { emailAlert.ProcessJobsWithStatus(0); // yield if (serviceStarted) { Thread.Sleep(new TimeSpan(0, 0, 1)); } } // time to end the thread Thread.CurrentThread.Abort(); } //job.process() public void Process() { try { //sets the status, DateTimeStarted, and the processId this.UpdateStatus(Status.InProgress); //do something logger.Debug("Updating Status to [Completed]"); //hits, status,DateFinished this.UpdateStatus(Status.Completed); } catch (Exception e) { logger.Error("Exception: " + e.Message); this.UpdateStatus(Status.Error); } finally { logger.Debug("Relasing semaphore"); semaphore.Release(); } I have tried to log what I can into a file to detect where the problem is happening, but so far I haven't been able to identify where this happens. Losing control of the Windows Form makes me think that this has nothing to do with processing the jobs. Any ideas?

    Read the article

  • SAT Thread and Process output capture in c#

    - by alex
    Hi: This is a strange problem I encountered. I have an window application written in c# to do testing. It has a MDI parent form that is hosting a few children forms. One of the forms launch test cripts by creating processes and capture the scripts output to a text box. Another form open serial port and monitoring the status of the device I am working on(like a shell). If I ran both of them together, the output of the script seems only appear in the text box after the test is done. However, If I don't open the serial port form, the output of the script is captured in real time. Does anyone knows what's causing the problem? I notice the onDataReceived even handler for serial port form has a [SAThread] header to it. Will this cause the serial port thread having higher priority than other processes? Thanks in advance.

    Read the article

  • multi thread in c question

    - by REALFREE
    Does mutex guarantee to execute thread in order of arriving? that is, if, thread 2 and thread 3 arrive is waiting while thread 1 is in critical section what exactly happen after thread 1 exit critical section if thread 2 arrive at mutex lock before thread 3, thread 2 will be allowed to enter critical section before thread 3 ? or race condition will be occurred?

    Read the article

< Previous Page | 21 22 23 24 25 26 27 28 29 30 31 32  | Next Page >