locking

问题 IN Eclipse i want to chnage the default editor of some .htm files. If i try to go to FIle Association and assiciate the default editor then file gets opened in that new editor but i don't get the syntax highlighting. The solution is that the file association is locked ny some plugin editor Preferences -- Context type----text ----Your editor -- reomve the extension But i get the .htm(locked) so i cant remove it. http://help.eclipse.org/juno/index.jsp?topic=%2Forg.eclipse.platform.doc.user

问题 IN Eclipse i want to chnage the default editor of some .htm files. If i try to go to FIle Association and assiciate the default editor then file gets opened in that new editor but i don't get the syntax highlighting. The solution is that the file association is locked ny some plugin editor Preferences -- Context type----text ----Your editor -- reomve the extension But i get the .htm(locked) so i cant remove it. http://help.eclipse.org/juno/index.jsp?topic=%2Forg.eclipse.platform.doc.user

问题 If a software project supports a version of Python that multiprocessing has been backported to, is there any reason to use threading.Lock over multiprocessing.Lock ? Would a multiprocessing lock not be thread safe as well? For that matter, is there a reason to use any synchronization primitives from threading that are also in multiprocessing ? 回答1: The threading module's synchronization primitive are lighter and faster than multiprocessing, due to the lack of dealing with shared semaphores,

问题 I have two ASP.NET web application. One is responsible for processing some info and writing to a log file , and the other application is reponsible for reading the log file and displays the information based on user request. Here's my code for the Writer public static void WriteLog(String PathToLogFile, String Message) { Mutex FileLock = new Mutex(false, "LogFileMutex"); try { FileLock.WaitOne(); using (StreamWriter sw = File.AppendText(FilePath)) { sw.WriteLine(Message); sw.Close(); } }

问题 I need to open a log file for writing. Trouble is, many things may do this at the same time, and I don't want conflicts. Each write will be a single line, generally about 150 bytes (and always less than 1K), and getting things in chronological order is not strictly required. I think what I want is to attempt to flock() , and if it fails, keep trying for a few seconds. If a lock can't be established after a number of tries, then give up. $fh=fopen($logfile, "a"); if (flock($fh, LOCK_EX|LOCK_NB

问题 I have many web service call (asychronous), in callback, I will plot result to Excel. I want to synchronize the plot method. So I use the following, however, from I track down in Visual Studio, every time, lock(locker) is successful, and there are many threads running clearcommentIfany, plot. I can't figure out why this is not working as expected! Thanks private readonly object locker = new object(); void ProcessPlot() { lock (locker) { Debug.WriteLine("currentThreadID: " + Thread

问题 I would like to know if there are any guidelineswhich a developer should follow as to when (and where) to place locks. For instance: I understand that code such as this should be locked, to avoid the possibility of another thread changing the value of SomeHeapValue unexpectedly. class Foo { public SomeHeapObject myObject; public void DoSummat(object inputValue_) { myObject.SomeHeapValue = inputValue_; } } My question is, however, how deep does one go with the locking? For instance, if we have

问题 How exactly i can destroy a pthread mutex variable ? Here is what i want to do. I want to have objects (structure variables) cached , which are looked up by key. I want to have minimum granularity of locks here. So i want to have a lock for each object probably embedded in the structure so that i can have object level locking. Now the problem is how to safely destroy these objects ? Looks like first step is to remove the object from the lookup table so that the object is not accessible in

问题 The java meomry model mandates that synchronize blocks that synchronize on the same monitor enforce a before-after-realtion on the variables modified within those blocks. Example: // in thread A synchronized( lock ) { x = true; } // in thread B synchronized( lock ) { System.out.println( x ); } In this case it is garanteed that thread B will see x==true as long as thread A already passed that synchronized -block. Now I am in the process to rewrite lots of code to use the more flexible (and

问题 I am trying to create a little benchmark (in Groovy) that shows high thread contention on a couple of synchronized methods. High contention should show up when monitoring voluntary context switches, and in Linux this can be achieved thanks to "pidstat". The program is the following: class Res { private int n; synchronized public void inc() { n++; def foo = [] for (int i = 0; i < 1000; ++i) foo << "hello" } synchronized public int getN() { return n; } } while (true) { Res res = new Res() int N