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Re: CoWork buggy!? [message #14982 is a reply to message #14979]

Mon, 24 March 2008 11:54

Werner
Messages: 234
Registered: May 2006
Location: Cologne / Germany

Experienced Member

Mindtraveller wrote on Mon, 24 March 2008 10:48

As far as I understand, CoWork detects number of processors present and tries to execute threads on different cores. Is that so?

I had quite a nice time Twisted Evil

analyzing "CoWork" (and multithreading under Ultimate++ in general) and sometimes I was painfully wrong Laughing

, but eventually - withs Mirek's help, of course - Rolling Eyes

I was able to document the whole stuff Very Happy

. So just look at this doc cutting (also published in the hope that Mirek will correct possibly still lurking errors Rolling Eyes

Quote:

Cf. ...upp/uppsrc/Core/CoWork.cpp

Pool();

Starts number_of_cpu(_core)s_+_2 Threads which will wait for jobs and do them as soon as they are available.

That is: all these Threads are delivered to the OS to be called by the OS when appropriate.

That means: as soon as Pool is constructed, the machine-dependant maximum number of Threads is active (periodically called by the OS) and waiting for jobs to do.

What, in the end, is periodically called by the OS, are number_of_cpu(_core)s_+_2 ThreadRun-methods (identifiable by the index passed while running "Pool()").

CoWork::Pool::Pool()
{
for(int i = 0; i < CPU_Cores() + 2; i++) // cpu( core)s + 2
threads.Add().Run(callback1(&ThreadRun, i)); // add Thread to Pool & start Thread
}

Werner

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