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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 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 non-blocking 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:

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

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

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 non-standard GNU extensions; hence the suffix "_np" (non-portable) 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 3.22 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/.

2008-11-11 Linux