pthread_tryjoin_np(3)      Library Functions Manual      pthread_tryjoin_np(3)

NAME
       pthread_tryjoin_np, pthread_timedjoin_np - try to join with a
       terminated thread

LIBRARY
       POSIX threads library (libpthread, -lpthread)

SYNOPSIS
       #define _GNU_SOURCE             /* See feature_test_macros(7) */
       #include <pthread.h>

       int pthread_tryjoin_np(pthread_t thread, void **retval);
       int pthread_timedjoin_np(pthread_t thread, void **retval,
                                const struct timespec *abstime);

DESCRIPTION
       These functions operate in the same way as pthread_join(3), except for
       the differences described on this page.

       The pthread_tryjoin_np() function performs a nonblocking join with the
       thread thread, returning the exit status of the thread in *retval.  If
       thread has not yet terminated, then instead of blocking, as is done by
       pthread_join(3), the call returns an error.

       The pthread_timedjoin_np() function performs a join-with-timeout.  If
       thread has not yet terminated, then the call blocks until a maximum
       time, specified in abstime, measured against the CLOCK_REALTIME clock.
       If the timeout expires before thread terminates, the call returns an
       error.  The abstime argument is a timespec(3) structure, specifying an
       absolute time measured since the Epoch (see time(2)).

RETURN VALUE
       On success, these functions return 0; on error, they return an error
       number.

ERRORS
       These functions can fail with the same errors as pthread_join(3).
       pthread_tryjoin_np() can in addition fail with the following error:

       EBUSY  thread had not yet terminated at the time of the call.

       pthread_timedjoin_np() can in addition fail with the following errors:

       EINVAL abstime value is invalid (tv_sec is less than 0 or tv_nsec is
              greater than 1e9).

       ETIMEDOUT
              The call timed out before thread terminated.

       pthread_timedjoin_np() never returns the error EINTR.

ATTRIBUTES
       For an explanation of the terms used in this section, see
       attributes(7).

       +--------------------------------------------+---------------+---------+
       |Interface                                   | Attribute     | Value   |
       +--------------------------------------------+---------------+---------+
       |pthread_tryjoin_np (), pthread_timedjoin_np | Thread safety | MT-Safe |
       |()                                          |               |         |
       +--------------------------------------------+---------------+---------+
STANDARDS
       GNU; hence the suffix "_np" (nonportable) in the names.

HISTORY
       glibc 2.3.3.

BUGS
       The pthread_timedjoin_np() function measures time by internally
       calculating a relative sleep interval that is then measured against the
       CLOCK_MONOTONIC clock instead of the CLOCK_REALTIME clock.
       Consequently, the timeout is unaffected by discontinuous changes to the
       CLOCK_REALTIME clock.

EXAMPLES
       The following code waits to join for up to 5 seconds:

           struct timespec ts;
           int s;

           ...

           if (clock_gettime(CLOCK_REALTIME, &ts) == -1) {
               /* Handle error */
           }

           ts.tv_sec += 5;

           s = pthread_timedjoin_np(thread, NULL, &ts);
           if (s != 0) {
               /* Handle error */
           }

SEE ALSO
       clock_gettime(2), pthread_exit(3), pthread_join(3), timespec(3),
       pthreads(7)

Linux man-pages 6.7               2023-10-31             pthread_tryjoin_np(3)