.\" $OpenBSD: pthread_join.3,v 1.6 2001/06/24 23:46:35 jasoni Exp $
.\" Copyright (c) 1996-1998 John Birrell <jb@cimlogic.com.au>.
.\" All rights reserved.
.\"
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.\"    must display the following acknowledgement:
.\"	This product includes software developed by John Birrell.
.\" 4. Neither the name of the author nor the names of any co-contributors
.\"    may be used to endorse or promote products derived from this software
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.\" $FreeBSD: pthread_join.3,v 1.6 1999/08/28 00:03:06 peter Exp $
.\"
.Dd April 4, 1996
.Dt PTHREAD_JOIN 3
.Os
.Sh NAME
.Nm pthread_join
.Nd wait for thread termination
.Sh SYNOPSIS
.Fd #include <pthread.h>
.Ft int
.Fn pthread_join "pthread_t thread" "void **value_ptr"
.Sh DESCRIPTION
The
.Fn pthread_join
function suspends execution of the calling thread until the target
.Fa thread
terminates unless the target
.Fa thread
has already terminated.
.Pp
On return from a successful
.Fn pthread_join
call with a non-NULL
.Fa value_ptr
argument, the value passed to
.Fn pthread_exit
by the terminating thread is stored in the location referenced by
.Fa value_ptr .
When a
.Fn pthread_join
returns successfully, the target thread has been terminated. The results
of multiple simultaneous calls to
.Fn pthread_join
specifying the same target thread are undefined. If the thread calling
.Fn pthread_join
is cancelled, then the target thread is not detached.
.Pp
A thread that has exited but remains unjoined counts against
[_POSIX_THREAD_THREADS_MAX].
.Sh RETURN VALUES
If successful, the
.Fn pthread_join
function will return zero. Otherwise an error number will be returned to
indicate the error.
.Sh ERRORS
.Fn pthread_join
will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The implementation has detected that the value specified by
.Fa thread
does not refer to a joinable thread.
.It Bq Er ESRCH
No thread could be found corresponding to that specified by the given
thread ID,
.Fa thread .
.It Bq Er EDEADLK
A deadlock was detected or the value of
.Fa thread
specifies the calling thread.
.El
.Sh SEE ALSO
.Xr wait 2 ,
.Xr pthread_create 3
.Sh STANDARDS
.Fn pthread_join
conforms to ISO/IEC 9945-1 ANSI/IEEE
.Pq Dq Tn POSIX
Std 1003.1 Second Edition 1996-07-12.