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Re: pthread reentrance issue on Visual Studio

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BlackLight wrote:
> 
> I am currently attempting to use pthreads for a C++ project under
> Visual Studio 2005 in a Windows environment. I am currently using
> pthreadVCE2.lib library for my purposes. The things went quite
> flawlessly so far, but now, because of some more complex requirements
> for my application, I need some more intensive multithreaded design,
> and this also implies to have some mutex lock attempts on the same
> mutex from the same thread which already got that mutex (since the
> same function may be called by different threads, I cannot know
> whether that thread already acquired that mutex or not). Here I got
> the issue, with my program looking as deadlocked. After a whole day
> spent debugging my mutexes in the application, I simply tried to run
> the following code:
> 
> #include <iostream>
> #include <pthread.h>
> 
> int main()
> {
>         pthread_mutex_t mutex;
>         pthread_mutex_init (&mutex, NULL);
> 
>         pthread_mutex_lock (&mutex);
>         std::cout << "Got lock 1\n";
>         pthread_mutex_lock (&mutex);
>         std::cout << "Got lock 2\n";
>         pthread_mutex_unlock (&mutex);
>         std::cout << "Released lock 1\n";
>         pthread_mutex_unlock (&mutex);
>         std::cout << "Released lock 2\n";
> 
>         return 0;
> }
> 
> And, surprise, this code deadlocks as well on "Got lock 1" (while, in
> the same moment, the same code runs flawlessly on my Cygwin
> environment using gcc). My question is: is it an issue with pthread
> library, with the version I'm using, or with my Visual Studio
> project's options? How to get everything correctly reentrant?

Unless you don't want to redesign your code to avoid the need for
recursive locking, use PTHREAD_MUTEX_RECURSIVE and non-null attr
parameter for pthread_mutex_init(), see pthread_mutexattr_settype().

regards,
alexander.

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Thread

pthread reentrance issue on Visual Studio BlackLight <blacklight86@gmail.com> - 2011-07-27 01:42 -0700
  Re: pthread reentrance issue on Visual Studio Alexander Terekhov <terekhov@web.de> - 2011-07-27 12:39 +0200
  Re: pthread reentrance issue on Visual Studio David Schwartz <davids@webmaster.com> - 2011-07-27 03:57 -0700

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