I've got se开发者_JAVA百科veral 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'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.
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.
You have to use synchronisation techniques
MSDN Thread Synchronization
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();
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?
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