Linux pthread_mutexattr_init?

[Loic Domaigne]

Hi! 

> I'm using glibc-2.3.3 on i386 platform running kernel 2.6.11. The man 
> page for pthread_mutexattr_init indicates I can use the 
> PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP type of Mutex however the only 
> type I can successfully build my program with is
> PTHREAD_MUTEX_INITIALIZER.
> 
> #include <pthread.h>
> pthread_mutex_t Q_lock = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP;
> 
> Causes the following error when I compile my pgm with gcc.
> 
> global.c:471: error: `PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP' 
> undeclared here (not in a function)
> 
> 
> Is the man page incorrect? Does Linux/glibc support the 
> PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP? If so is there a trick to using 
> other than the default PTHREAD_MUTEX_INITIALIZER type of mutex?

It is not an error in the man page. You must enable the GNU extension with
the flag -D_GNU_SOURCE to gcc in order to access such non portable (hence
the ending in "_NP") features. 


HTH,
Loic. 

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