Re: posix semaphores not working under gdb

[Daniel Juan <daniel.juan@gmail.com>]

You are right Kenny,

if you look at the doc in NTPL:

man 3p sem_wait

The  sem_trywait()  and sem_wait() functions shall return zero if the
calling process successfully performed the semaphore lock operation on
the semaphore designated by sem.If the call was unsuccessful, the
state of the semaphore shall be unchanged, and the function shall
return a value of -1 and set errno to indicate the error.


If you look at Linuxthreads

man 3 sem_wait

The sem_wait and sem_getvalue functions always return 0.


Thanks

On 12/1/05, Kenny Simpson <theonetruekenny@yahoo.com> wrote:
> One thing that caused me some pain a while ago is the semaphore behavioral change in NPTL vs
> LinuxThreads.  Under LinuxThreads, sem_wait will never return until the semaphore is aquired.
> With NPTL, sem_wait can return EINTR
> ... and DOES when gdb attaches.
>
> The man pages in many distrubutions still have the old LinuxThreads documentation which explictly
> states that sem_wait will not be affected by signals.
>
> Hope this helps...
> -Kenny
>
>
>
>
>
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--
Daniel Juan Boned
e-mail: daniel(dot)juan(at)gmail.com