xref: /illumos-gate/usr/src/man/man3c/pthread_join.3c (revision 4c28a617e3922d92a58e813a5b955eb526b9c386)

Sun Microsystems, Inc. gratefully acknowledges The Open Group for
permission to reproduce portions of its copyrighted documentation.
Original documentation from The Open Group can be obtained online at
http://www.opengroup.org/bookstore/.

The Institute of Electrical and Electronics Engineers and The Open
Group, have given us permission to reprint portions of their
documentation.

In the following statement, the phrase ``this text'' refers to portions
of the system documentation.

Portions of this text are reprinted and reproduced in electronic form
in the SunOS Reference Manual, from IEEE Std 1003.1, 2004 Edition,
Standard for Information Technology -- Portable Operating System
Interface (POSIX), The Open Group Base Specifications Issue 6,
Copyright (C) 2001-2004 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy
between these versions and the original IEEE and The Open Group
Standard, the original IEEE and The Open Group Standard is the referee
document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html.

This notice shall appear on any product containing this material.

The contents of this file are subject to the terms of the
Common Development and Distribution License (the "License").
You may not use this file except in compliance with the License.

You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
or http://www.opensolaris.org/os/licensing.
See the License for the specific language governing permissions
and limitations under the License.

When distributing Covered Code, include this CDDL HEADER in each
file and include the License file at usr/src/OPENSOLARIS.LICENSE.
If applicable, add the following below this CDDL HEADER, with the
fields enclosed by brackets "[]" replaced with your own identifying
information: Portions Copyright [yyyy] [name of copyright owner]


Copyright 1991, 1992, 1994, The X/Open Company Ltd.
Copyright (c) 2001, The IEEE and The Open Group. All Rights Reserved.
Copyright (c) 2008, Sun Microsystems, Inc. All Rights Reserved.

PTHREAD_JOIN 3C "Mar 23, 2005"
NAME
pthread_join - wait for thread termination
SYNOPSIS

cc -mt [ flag... ] file... -lpthread [ library... ]
#include <pthread.h>

int pthread_join(pthread_t thread, void **status);
DESCRIPTION

The pthread_join() function suspends processing of the calling thread until the target thread completes. thread must be a member of the current process and it cannot be a detached thread. See pthread_create(3C).

If two or more threads wait for the same thread to complete, all will suspend processing until the thread has terminated, and then one thread will return successfully and the others will return with an error of ESRCH. The pthread_join() function will not block processing of the calling thread if the target thread has already terminated.

If a pthread_join() call returns successfully with a non-null status argument, the value passed to pthread_exit(3C) by the terminating thread will be placed in the location referenced by status.

If the pthread_join() calling thread is cancelled, then the target thread will remain joinable by pthread_join(). However, the calling thread may set up a cancellation cleanup handler on thread prior to the join call, which may detach the target thread by calling pthread_detach(3C). See pthread_detach(3C) and pthread_cancel(3C).

RETURN VALUES

If successful, pthread_join() returns 0. Otherwise, an error number is returned to indicate the error.

ERRORS
EDEADLK

A joining deadlock would occur, such as when a thread attempts to wait for itself.

EINVAL

The thread corresponding to the given thread ID is a detached thread.

ESRCH

No thread could be found corresponding to the given thread ID.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE
Interface Stability Standard
MT-Level MT-Safe
SEE ALSO

pthread_cancel(3C), pthread_create(3C), pthread_detach(3C), pthread_exit(3C), wait(3C), attributes(5), standards(5)

NOTES

The pthread_join(3C) function must specify the thread ID for whose termination it will wait.

Calling pthread_join() also "detaches" the thread; that is, pthread_join() includes the effect of the pthread_detach() function. If a thread were to be cancelled when blocked in pthread_join(), an explicit detach would have to be performed in the cancellation cleanup handler. The pthread_detach() function exists primarily for this purpose.