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 */
}
SEE ALSOclock_gettime(2), pthread_exit(3), pthread_join(3), pthreads(7)COLOPHON
This page is part of release 4.14 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the
latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
Linux 2017-09-15 PTHREAD_TRYJOIN_NP(3)
