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Subject: Re: CS551 confusing about child thread?
Date: Sat, 06 Sep 2008 13:56:58 -0700
From: Bill Cheng <william@bourbon.usc.edu>

Someone wrote:

  > I declared a global variable (e.g. NumOfChildThread =0) to keep track 
  > total numbers of child threads in server.
  > 
  > But whenever I do NumOfChildThread++ in fork() loop, the parent's 
  > NumOfChildThread doesn't increase accordant with child thread.
  > 
  > It seems like child thread CREATE his own NumOfChildThread and this new 
  > variable doesn't has any relation with parents.
  > 
  > In this situation, how do I keep track child thread, because since each 
  > variable or array define in main() cannot synchronize with child thread.

If you are using child "thread", you should not fork()!
Forking is to create a child "process".  A child process
does *not* share memory content with its parent process!

I think what you want is pthread_create() and not fork().
If you want to use fork(), you need to increment the
number of child variable in the parent process.
--
Bill Cheng // bill.cheng@usc.edu <URL:http://merlot.usc.edu/william/usc/>