| .\" Copyright (c) 2008 Linux Foundation, written by Michael Kerrisk |
| .\" <mtk.manpages@gmail.com> |
| .\" |
| .\" %%%LICENSE_START(VERBATIM) |
| .\" Permission is granted to make and distribute verbatim copies of this |
| .\" manual provided the copyright notice and this permission notice are |
| .\" preserved on all copies. |
| .\" |
| .\" Permission is granted to copy and distribute modified versions of this |
| .\" manual under the conditions for verbatim copying, provided that the |
| .\" entire resulting derived work is distributed under the terms of a |
| .\" permission notice identical to this one. |
| .\" |
| .\" Since the Linux kernel and libraries are constantly changing, this |
| .\" manual page may be incorrect or out-of-date. The author(s) assume no |
| .\" responsibility for errors or omissions, or for damages resulting from |
| .\" the use of the information contained herein. The author(s) may not |
| .\" have taken the same level of care in the production of this manual, |
| .\" which is licensed free of charge, as they might when working |
| .\" professionally. |
| .\" |
| .\" Formatted or processed versions of this manual, if unaccompanied by |
| .\" the source, must acknowledge the copyright and authors of this work. |
| .\" %%%LICENSE_END |
| .\" |
| .TH PTHREAD_TRYJOIN_NP 3 2021-03-22 "Linux" "Linux Programmer's Manual" |
| .SH NAME |
| pthread_tryjoin_np, pthread_timedjoin_np \- try to join with a |
| terminated thread |
| .SH SYNOPSIS |
| .nf |
| .BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */" |
| .B #include <pthread.h> |
| .PP |
| .BI "int pthread_tryjoin_np(pthread_t " thread ", void **" retval ); |
| .BI "int pthread_timedjoin_np(pthread_t " thread ", void **" retval , |
| .BI " const struct timespec *" abstime ); |
| .fi |
| .PP |
| Compile and link with \fI\-pthread\fP. |
| .SH DESCRIPTION |
| These functions operate in the same way as |
| .BR pthread_join (3), |
| except for the differences described on this page. |
| .PP |
| The |
| .BR pthread_tryjoin_np () |
| function performs a nonblocking join with the thread |
| .IR thread , |
| returning the exit status of the thread in |
| .IR *retval . |
| If |
| .I thread |
| has not yet terminated, then instead of blocking, as is done by |
| .BR pthread_join (3), |
| the call returns an error. |
| .PP |
| The |
| .BR pthread_timedjoin_np () |
| function performs a join-with-timeout. |
| If |
| .I thread |
| has not yet terminated, |
| then the call blocks until a maximum time, specified in |
| .IR abstime , |
| measured against the |
| .BR CLOCK_REALTIME |
| clock. |
| If the timeout expires before |
| .I thread |
| terminates, |
| the call returns an error. |
| The |
| .I abstime |
| argument is a structure of the following form, |
| specifying an absolute time measured since the Epoch (see |
| .BR time (2)): |
| .PP |
| .in +4n |
| .EX |
| struct timespec { |
| time_t tv_sec; /* seconds */ |
| long tv_nsec; /* nanoseconds */ |
| }; |
| .EE |
| .in |
| .SH RETURN VALUE |
| On success, |
| these functions return 0; |
| on error, they return an error number. |
| .SH ERRORS |
| These functions can fail with the same errors as |
| .BR pthread_join (3). |
| .BR pthread_tryjoin_np () |
| can in addition fail with the following error: |
| .TP |
| .B EBUSY |
| .I thread |
| had not yet terminated at the time of the call. |
| .PP |
| .BR pthread_timedjoin_np () |
| can in addition fail with the following errors: |
| .TP |
| .BR ETIMEDOUT |
| The call timed out before |
| .I thread |
| terminated. |
| .TP |
| .BR EINVAL |
| .I abstime |
| value is invalid |
| .RI ( tv_sec |
| is less than 0 or |
| .IR tv_nsec |
| is greater than 1e9). |
| .PP |
| .BR pthread_timedjoin_np () |
| never returns the error |
| .BR EINTR . |
| .SH VERSIONS |
| These functions first appeared in glibc in version 2.3.3. |
| .SH ATTRIBUTES |
| For an explanation of the terms used in this section, see |
| .BR attributes (7). |
| .ad l |
| .nh |
| .TS |
| allbox; |
| lbx lb lb |
| l l l. |
| Interface Attribute Value |
| T{ |
| .BR pthread_tryjoin_np (), |
| .BR pthread_timedjoin_np () |
| T} Thread safety MT-Safe |
| .TE |
| .hy |
| .ad |
| .sp 1 |
| .SH CONFORMING TO |
| These functions are nonstandard GNU extensions; |
| hence the suffix "_np" (nonportable) in the names. |
| .SH EXAMPLES |
| The following code waits to join for up to 5 seconds: |
| .PP |
| .in +4n |
| .EX |
| 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 */ |
| } |
| .EE |
| .in |
| .SH BUGS |
| The |
| .BR pthread_timedjoin_np () |
| function measures time by internally calculating a relative sleep interval |
| that is then measured against the |
| .BR CLOCK_MONOTONIC |
| clock instead of the |
| .BR CLOCK_REALTIME |
| clock. |
| Consequently, the timeout is unaffected by discontinuous changes to the |
| .BR CLOCK_REALTIME |
| clock. |
| .SH SEE ALSO |
| .BR clock_gettime (2), |
| .BR pthread_exit (3), |
| .BR pthread_join (3), |
| .BR pthreads (7) |