Re: [Threads-devel] may be a bug in boost.thread on freebsd 8.0

Subject: Re: [Threads-devel] may be a bug in boost.thread on freebsd 8.0
From: Anthony Williams (anthony_at_[hidden])
Date: 2010-07-28 09:23:45

On 28/07/10 13:15, å×ÇÅÎÉÊ ûÕÂÉÎ wrote:
> I use boost1.43 on freebsd8.0 amd64, installed from ports.
> Here is a simple program that causes an assertion:
>
>    Assertion failed: (!pthread_cond_wait(&cond,m.mutex()->native_handle())), function wait, file ./boost/thread/pthread/condition_variable.hpp, line 20.
>
> during execution.
>
> #include<boost/thread.hpp>
> #include<cstdlib>
>
> using namespace std;
>
> void ThreadFun(int number)
> {
>      sleep(5);
> }
>
> int main(int argc, char** argv)
> {
>      if (argc>  1)
>      {
>          pid_t pid = fork();
>          if (pid<  0)
>          {
>              return EXIT_FAILURE;
>          }
>          else if (pid>  0)
>          {
>              return EXIT_SUCCESS;
>          }
>      }
>      boost::thread th1(boost::bind(&ThreadFun, 1));
>      th1.join();
>      return EXIT_SUCCESS;
> }
>
> Error occurs only when I execute program with command line arguments(when the process forks)
> and only on freebsd 8.0 (on ubuntu 10.04 x64 and on freebsd 7.3 amd 64 it works correct).
>
> Is it a bug or did something wrong?

Looks to me like fork() doesn't interact well with the thread library on 
freebsd 8.0 --- does it work if you use raw POSIX threads and condition 
variables?

Since you create the thread AFTER the fork, it would suggest to me that 
the library isn't correctly initialized when forking.

Anthony
-- 
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