pthread_tryjoin_np(3) — Linux manual pages

Linux manual pages	Section 3: Subroutines

Name

pthread_tryjoin_np, pthread_timedjoin_np — try to join with a terminated 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)`;

	Note
	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 */
    }

COLOPHON

This page is part of release 3.52 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/.

  Copyright (c) 2008 Linux Foundation, written by Michael Kerrisk
    <mtk.manpagesgmail.com>

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