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PTHREAD_TRYJOIN_NP(3) Linux Programmer's Manual PTHREAD_TRYJOIN_NP(3)

NAME

     pthread_tryjoin_np,  pthread_timedjoin_np  -  try to join with a termi-
     nated thread

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);

     Compile and link with -pthread.

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.  If the timeout expires before thread  ter-
     minates,  the  call returns an error.  The abstime argument is a struc-
     ture of the following form, specifying an absolute time measured  since
     the Epoch (see time(2)):

         struct timespec {
             time_t tv_sec;     /* seconds */
             long   tv_nsec;    /* nanoseconds */ };

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:

     ETIMEDOUT
            The call timed out before thread terminated.

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

     pthread_timedjoin_np() never returns the error EINTR.

VERSIONS

     These functions first appeared in glibc in version 2.3.3.

ATTRIBUTES

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

     +-----------------------+---------------+---------+
     |Interface              | Attribute     | Value   |
     +-----------------------+---------------+---------+
     |pthread_tryjoin_np(),  | Thread safety | MT-Safe |
     |pthread_timedjoin_np() |               |         |
     +-----------------------+---------------+---------+

CONFORMING TO

     These  functions are nonstandard GNU extensions; hence the suffix "_np"
     (nonportable) in the names.

EXAMPLE

     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 */ }