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Re: [PATCH 1/2] posix: Correctly enable/disable cancellation on Linux posix_spawn
On 20/09/2016 16:24, Florian Weimer wrote:
> * Adhemerval Zanella:
>
>> + int e = pthread_barrier_wait (&b);
>> + if (e != 0 && e != PTHREAD_BARRIER_SERIAL_THREAD)
>> + {
>> + puts ("error: pthread_barrier_wait failed");
>> + exit (1);
>> + }
>
> We have xpthread_barrier_wait now (also below).
>
Ack, I will change to xpthread_barrier_wait.
>> + /* The test basically pipes a 'echo $$' created by a thread with a
>> + cancellation pending. It then checks if the thread is not
>> + cancelled, the process is created, and if the output is the expected
>> + one (the process pid). */
>
> Don't you have to try this multiple times, to see if you can hit the
> race?
Not in this test because the idea is to check if posix_spawn acts or not
on a pending cancellation, not if an asynchronous cancellation cancels the
thread while the thread executes posix_spawn.
>
>> +
>> + if (pipe (targ.fd) != 0)
>> + {
>> + puts ("error: pipe failed");
>> + exit (1);
>> + }
>> +
>> + /* Not interested in knowing when the pipe is closed. */
>> + if (sigignore (SIGPIPE) != 0)
>> + {
>> + puts ("error: sigignore failed");
>> + exit (1);
>> + }
>> +
>> + if (pthread_barrier_init (&b, NULL, 2) != 0)
>> + {
>> + puts ("error: pthread_barrier_init failed");
>> + exit (1);
>> + }
>> +
>> + pthread_t th;
>> + if (pthread_create (&th, NULL, tf, &targ) != 0)
>
> xpthread_create.
Ack.
>
>> + if (pthread_join (th, &r) != 0)
>
> xpthread_join.
>
Ack.