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pthread_tryjoin_np

NAME

pthread_tryjoin_np, pthread_timedjoin_np - try to join with a terminated thread

SYNOPSIS

 #define _GNU_SOURCE
 #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 terminates, the call returns an error. The abstime argument is a structure 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 error:

ETIMEDOUT

The call timed out before thread terminated.

pthread_timedjoin_np() never returns the error EINTR.

VERSIONS

These functions first appeared in glibc in version 2.3.3.

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 */
     }
 

SEE ALSO

clock_gettime(2), pthread_join(3), pthread_exit(3), pthreads(7)

COLOPHON

This page is part of release 3.25 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.