locking

does anyone have any ideas on whats the best way to implement a lock so that after X number of seconds it will automatically be released ? Josh Pearce In web development, I cache all the time with a sliding timeout. Perhaps you could use a cached object as the lock? Here's a discussion of caching technologies in non-web applications: Caching in C# without System.Web Assuming you are looking for an event to fire in X seconds, then I don't think there's any core Mutex object which currently provides the type of functionality you are looking for. You could create this type of functionality by

I am trying to protect data inside my thread from the main thread. I have the following code: lock = threading.Lock() def createstuff(data): t= threading.Thread(target=func, args=(data,)) t.start() def func(val): with lock: print 'acquired' time.sleep(2) print ('Value: %s, : %s'%(val, threading.currentThread().getName())) print 'released\n' ags_list = ['x'] createstuff(ags_list) rn =random.randint(5,50) print 'random no:', rn ags_list[0] = rn It produces the Output: acquired random no: 10 Value: [10], : Thread-1 released Why does changing the list in main thread cause the list inside another

rephrased for clarity I would like to be able to mix the use of the synchronized block with more explicit locking via calling lock and release methods directly when appropriate. Thus allowing me the syntaxtical sugar of using sychtronized(myObject) when I can get away with it, but also being able to call myObject.lock & myObject.unlock dierctly for those times when a synchronized block is not flexible enough to do what I need done. I know that every single Object has, implicitly, a rentrant lock built into it which is used by the synchronized block. Effectively the the lock mthod is caled on

Highly there is a problem in this lock but i couldn't understand what is that. I have strong suspicious that below example doesn't lock enough well. So what can be problem ? class example { object locker = new object(); void start() { for (int i = 0; i < 1000; i++) { (new Thread(dostuff)).Start(); } } void dostuff() { lock (locker) { //dosomething } } } Your code creates 1000 Threads. That is enormously expensive, requiring over 1 GB of memory. And then all those threads compete for a single lock, essentially serialzing (de-threading) the whole operation. But your lock works fine, nothing

Imagine that I have a shared folder MyShared: User A, gets the file \MyShared:\Foo.txt after every 30 seconds. And I overwrite \MyShared:\Foo.txt also after every 28 seconds (within my PowerShell script) How can I prevent myself to overwrite this file while the user is getting it, in PowerShell? (I do not want to break the content of the file or end-up with some error by attempting to overwrite it in the time of user retrieving it) If I rephrase the question : How can I force a Powershell script to wait overwriting a file until another process is finished reading it? In some cases, you may not

Is there a way to unlock a file on Windows with a Python script? The file is exclusively locked by another process. I need a solution without killing or interupting the locking process. I already had a look at portalocker , a portable locking implementation. But this needs a file handle to unlock, which I can not get, as the file is already locked by the locking process. If there is no way, could someone lead me to the Windows API doc which describes the problem further? Anything you do will affect the other process if that process thinks it has a lock on the file then breaking the lock means