Threads pausing and resuming c#

Question

I've got several threads ,how can I pause/resume them?

From duplicate question:

How can i pause 5 threads, and to remember their status. Because one of them is eating another is thinking, etc.

If you think you need to Pause threads, you've got problems you're not aware of. — H H, Feb 19 '11 at 19:54

score 15 · Accepted Answer · answered Feb 19 '11 at 19:52

If you're using System.Threading.Thread, then you can call Suspend and Resume. This, however is not recommended. There's no telling what a thread might be doing when you call Suspend. If you call Suspend while the thread holds a lock, for example, or has a file open for exclusive access, nothing else will be able to access the locked resource.

As the documentation for Thread.Suspend says:

Do not use the Suspend and Resume methods to synchronize the activities of threads. You have no way of knowing what code a thread is executing when you suspend it. If you suspend a thread while it holds locks during a security permission evaluation, other threads in the AppDomain might be blocked. If you suspend a thread while it is executing a class constructor, other threads in the AppDomain that attempt to use that class are blocked. Deadlocks can occur very easily.

Typically, you control threads' activity using synchronization primitives like events. A thread will wait on an event (look into AutoResetEvent and ManualResetEvent). Or, if a thread is servicing a queue, you'll use something like BlockingCollection so that the thread can wait for something to be put into the queue. All of these non-busy wait techniques are much better than arbitrarily suspending and restarting a thread, and don't suffer from the potential disastrous consequences.

score 2 · Answer 2 · edited Jun 20 '20 at 09:12

2

You have to use synchronisation techniques

MSDN Thread Synchronization

edited Jun 20 '20 at 09:12

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answered Feb 19 '11 at 19:50

Mola.Studio

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That document is very old -- 2005. As other answers mentioned, you probably want to use threadsafe queues or some such to achieve your actual goal, rather than adding a layer of arbitrary and error prone synchronization with event wait primitives. – Tom A Mar 14 '13 at 00:24
http://stackoverflow.com/questions/10721148/how-to-implement-thread-safe-queues is a pretty good recap of the topic – Bryan Devaney Apr 04 '13 at 15:44

score 2 · Answer 3 · edited May 23 '17 at 11:45

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Have a look at Monitor.Wait and Monitor.Pulse in the first instance- Marc Gravell has a nice example used in a queue here.

In it quite likely that you want to consider using a Producer/Consumer queue.

edited May 23 '17 at 11:45

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answered Feb 19 '11 at 19:53

RichardOD

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score 1 · Answer 4 · answered Feb 19 '11 at 22:05

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In the main thread:

ManualResetEvent re = new ManualResetEvent(true);

In all the threads, at "strategic" points:

re.WaitOne();

In the main thread, to stop the threads:

re.Reset();

and to restart:

re.Set();

answered Feb 19 '11 at 22:05

xanatos

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score 0 · Answer 5 · edited May 23 '17 at 11:50

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You can use Suspend() and Resume().
http://msdn.microsoft.com/en-us/library/system.threading.thread.resume.aspx
http://msdn.microsoft.com/en-us/library/system.threading.thread.suspend.aspx
You can also read:
What are alternative ways to suspend and resume a thread?

edited May 23 '17 at 11:50

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answered Feb 19 '11 at 19:55

Sergey Gavruk

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Threads pausing and resuming c#

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