Re: Last version of message queues.

[Ross Johnson <rpj at ise dot canberra dot edu dot au>]

Aurelio,

Ross Johnson wrote:
> 
> Hi Aurelio,
> 
> Last time I looked you needed PTHREAD_PROCESS_SHARED mutexes
> and condition variables. The code you just sent does the same
> as last time.
> 
> _POSIX_THREAD_PROCESS_SHARED isn't defined in pthreads-win32, nor
> in Linux I believe (although I could be out of date there).
> 
> For example, in  mq_open() you have the following code:
> 
>         if ( (i = pthread_mutexattr_init(&mattr)) != 0)
>            goto pthreaderr;
>         pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);
>         i = pthread_mutex_init(&mqhdr->mqh_lock, &mattr);
>         pthread_mutexattr_destroy(&mattr);      /* be sure to destroy */
>         if (i != 0)
>            goto pthreaderr;
> 
>         if ( (i = pthread_condattr_init(&cattr)) != 0)
>            goto pthreaderr;
>         pthread_condattr_setpshared(&cattr, PTHREAD_PROCESS_SHARED);
>         i = pthread_cond_init(&mqhdr->mqh_wait, &cattr);
> 
> The *attr_setpshared() calls will be returning ENOSYS errors.
> 

I apologise - it's pthread_{mutex,cond}_init() that should be
returning ENOSYS, not *attr_setpshared(). Since you're catching
that I'm now confused so I'll go take a longer harder look.

Sorry.
Ross