xref: /illumos-gate/usr/src/man/man3c/thr_join.3c (revision bbf21555)

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]


Portions Copyright (c) 1995 IEEE. All Rights Reserved.
Copyright (c) 2000 Sun Microsystems, Inc. All Rights Reserved.
Copyright (c) 2001, The IEEE and The Open Group. All Rights Reserved.

THR_JOIN 3C "Mar 27, 2000"
NAME
thr_join - wait for thread termination
SYNOPSIS

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

int thr_join(thread_t thread, thread_t *departed, void **status);
DESCRIPTION

The thr_join() function suspends processing of the calling thread until the target thread completes. The thread argument must be a member of the current process and cannot be a detached thread. See thr_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 thr_join() function will not block processing of the calling thread if the target thread has already terminated.

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

If the target thread ID is 0, thr_join() finds and returns the status of a terminated undetached thread in the process. If no such thread exists, it suspends processing of the calling thread until a thread for which no other thread is waiting enters that state, at which time it returns successfully, or until all other threads in the process are either daemon threads or threads waiting in thr_join(), in which case it returns EDEADLK. See NOTES.

If departed is not NULL, it points to a location that is set to the ID of the terminated thread if thr_join() returns successfully.

RETURN VALUES

If successful, thr_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, or the calling thread is waiting for any thread to exit and only daemon threads or waiting threads exist in the process.

ESRCH

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

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE
MT-Level MT-Safe
SEE ALSO

thr_create (3C), thr_exit (3C), wait (3C), attributes (7), standards (7)

NOTES

Using thr_join(3C) in the following syntax,

while (thr_join(0, NULL, NULL) == 0);

will wait for the termination of all non-daemon threads, excluding threads that are themselves waiting in thr_join().