NetBSD/lib/libpthread/pthread_join.3

.\" $NetBSD: pthread_join.3,v 1.6 2010/07/09 10:55:11 wiz Exp $
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.\" $FreeBSD: src/lib/libpthread/man/pthread_join.3,v 1.13 2002/09/16 19:29:28 mini Exp $
.\"
.Dd July 9, 2010
.Dt PTHREAD_JOIN 3
.Os
.Sh NAME
.Nm pthread_join
.Nd wait for thread termination
.Sh LIBRARY
.Lb libpthread
.Sh SYNOPSIS
.In 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
.Pf non- Dv 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
.Dv _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
shall fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
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 .
.El
.Pp
.Fn pthread_join
may fail if:
.Bl -tag -width Er
.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
The function conforms to
.St -p1003.1-2001 .