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Implement PThreads barriers and barrier attributes.

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This commit is contained in:
mtm 2004-02-19 13:51:52 +00:00
parent 88ba2a7fa4
commit 92fa088800
9 changed files with 551 additions and 1 deletions
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2
lib/libthr/thread/Makefile.inc
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@ -6,6 +6,8 @@
SRCS+= \
thr_attr.c \
thr_autoinit.c \
thr_barrier.c \
thr_barrierattr.c \
thr_cancel.c \
thr_clean.c \
thr_concurrency.c \

129
lib/libthr/thread/thr_barrier.c Normal file
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@ -0,0 +1,129 @@
/*-
* Copyright (c) 2004 Michael Telahun Makonnen <mtm@FreeBSD.Org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include "thr_private.h"
__weak_reference(_pthread_barrier_destroy, pthread_barrier_destroy);
__weak_reference(_pthread_barrier_init, pthread_barrier_init);
__weak_reference(_pthread_barrier_wait, pthread_barrier_wait);
int
_pthread_barrier_destroy(pthread_barrier_t *barrier)
{
if (*barrier == NULL)
return (EINVAL);
if ((*barrier)->b_subtotal > 0)
return (EBUSY);
PTHREAD_ASSERT((*barrier)->b_subtotal == 0,
"barrier count must be zero when destroyed");
free(*barrier);
*barrier = NULL;
return (0);
}
int
_pthread_barrier_init(pthread_barrier_t *barrier,
const pthread_barrierattr_t attr, unsigned int count)
{
if (count < 1)
return (EINVAL);
*barrier =
(struct pthread_barrier *)malloc(sizeof(struct pthread_barrier));
if (*barrier == NULL)
return (ENOMEM);
memset((void *)*barrier, 0, sizeof(struct pthread_barrier));
(*barrier)->b_total = count;
TAILQ_INIT(&(*barrier)->b_barrq);
return (0);
}
int
_pthread_barrier_wait(pthread_barrier_t *barrier)
{
struct pthread_barrier *b;
struct pthread *ptd;
int error;
if (*barrier == NULL)
return (EINVAL);
/*
* Check if threads waiting on the barrier can be released. If
* so, release them and make this last thread the special thread.
*/
error = 0;
b = *barrier;
UMTX_LOCK(&b->b_lock);
if (b->b_subtotal == (b->b_total - 1)) {
TAILQ_FOREACH(ptd, &b->b_barrq, sqe) {
_thread_critical_enter(ptd);
PTHREAD_NEW_STATE(ptd, PS_RUNNING);
TAILQ_REMOVE(&b->b_barrq, ptd, sqe);
ptd->flags |= PTHREAD_FLAGS_BARR_REL;
_thread_critical_exit(ptd);
}
b->b_subtotal = 0;
UMTX_UNLOCK(&b->b_lock);
return (PTHREAD_BARRIER_SERIAL_THREAD);
}
/*
* More threads need to reach the barrier. Suspend this thread.
*/
_thread_critical_enter(curthread);
TAILQ_INSERT_HEAD(&b->b_barrq, curthread, sqe);
PTHREAD_NEW_STATE(curthread, PS_BARRIER_WAIT);
_thread_critical_exit(curthread);
b->b_subtotal++;
PTHREAD_ASSERT(b->b_subtotal < b->b_total,
"the number of threads waiting at a barrier is too large");
UMTX_UNLOCK(&b->b_lock);
do {
error = _thread_suspend(curthread, NULL);
if (error == EINTR) {
/*
* Make sure this thread wasn't released from
* the barrier while it was handling the signal.
*/
_thread_critical_enter(curthread);
if ((curthread->flags & PTHREAD_FLAGS_BARR_REL) != 0) {
curthread->flags &= ~PTHREAD_FLAGS_BARR_REL;
_thread_critical_exit(curthread);
error = 0;
break;
}
PTHREAD_NEW_STATE(curthread, PS_BARRIER_WAIT);
_thread_critical_exit(curthread);
}
} while (error == EINTR);
return (error);
}

79
lib/libthr/thread/thr_barrierattr.c Normal file
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@ -0,0 +1,79 @@
/*-
* Copyright (c) 2004 Michael Telahun Makonnen <mtm@FreeBSD.Org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <pthread.h>
#include <stdlib.h>
#include "thr_private.h"
__weak_reference(_pthread_barrierattr_destroy, pthread_barrierattr_destroy);
__weak_reference(_pthread_barrierattr_init, pthread_barrierattr_init);
__weak_reference(_pthread_barrierattr_getpshared,
pthread_barrierattr_getpshared);
__weak_reference(_pthread_barrierattr_setpshared,
pthread_barrierattr_setpshared);
int
_pthread_barrierattr_destroy(pthread_barrierattr_t *attr)
{
if (*attr == NULL)
return (EINVAL);
free(*attr);
*attr = NULL;
return (0);
}
int
_pthread_barrierattr_init(pthread_barrierattr_t *attr)
{
*attr =
(pthread_barrierattr_t)malloc(sizeof(struct pthread_barrierattr));
if ((*attr) == NULL)
return (ENOMEM);
(*attr)->ba_pshared = PTHREAD_PROCESS_PRIVATE;
return (0);
}
int
_pthread_barrierattr_getpshared(const pthread_barrierattr_t *attr, int *pshared)
{
if (*attr == NULL)
return (EINVAL);
*pshared = (*attr)->ba_pshared;
return (0);
}
int
_pthread_barrierattr_setpshared(pthread_barrierattr_t *attr, int pshared)
{
if (*attr == NULL || (pshared != PTHREAD_PROCESS_PRIVATE &&
pshared != PTHREAD_PROCESS_SHARED))
return (EINVAL);
(*attr)->ba_pshared = pshared;
return (0);
}

1
lib/libthr/thread/thr_cancel.c
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@ -93,6 +93,7 @@ _pthread_cancel(pthread_t pthread)
PTHREAD_NEW_STATE(pthread, PS_RUNNING);
break;
case PS_BARRIER_WAIT:
case PS_MUTEX_WAIT:
case PS_COND_WAIT:
/*

19
lib/libthr/thread/thr_private.h
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@ -146,7 +146,6 @@
PTHREAD_SET_STATE(thrd, newstate); \
} while (0)
/*
* TailQ initialization values.
*/
@ -368,6 +367,22 @@ extern int _pthread_page_size;
*/
#define GET_CURRENT_TOD(tv) gettimeofday(&(tv), NULL)
struct pthread_barrierattr {
int ba_pshared;
};
/*
* POSIX Threads barrier object.
* Lock order:
* 1. pthread_barrier
* 2. pthread
*/
struct pthread_barrier {
TAILQ_HEAD(barrq_head, pthread) b_barrq;
struct umtx b_lock;
int b_total;
int b_subtotal;
};
struct pthread_rwlockattr {
int pshared;
@ -388,6 +403,7 @@ enum pthread_state {
PS_RUNNING,
PS_MUTEX_WAIT,
PS_COND_WAIT,
PS_BARRIER_WAIT,
PS_SLEEP_WAIT, /* XXX We need to wrap syscalls to set this state */
PS_WAIT_WAIT,
PS_JOIN,
@ -535,6 +551,7 @@ struct pthread {
int flags;
#define PTHREAD_FLAGS_PRIVATE 0x0001
#define PTHREAD_EXITING 0x0002
#define PTHREAD_FLAGS_BARR_REL 0x0004 /* has been released from barrier */
#define PTHREAD_FLAGS_IN_CONDQ 0x0080 /* in condition queue using sqe link*/
#define PTHREAD_FLAGS_IN_MUTEXQ 0x0100 /* in mutex queue using sqe link */
#define PTHREAD_FLAGS_SUSPENDED 0x0200 /* thread is suspended */

7
lib/libthr/thread/thr_sig.c
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@ -130,6 +130,13 @@ _thread_sig_wrapper(int sig, siginfo_t *info, void *context)
* after cleanup handling.
*/
switch (curthread->state) {
case PS_BARRIER_WAIT:
/*
* XXX - The thread has reached the barrier. We can't
* "back it away" from the barrier.
*/
_thread_critical_enter(curthread);
break;
case PS_COND_WAIT:
/*
* Cache the address, since it will not be available

8
share/man/man3/Makefile
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@ -140,6 +140,8 @@ PTHREAD_MAN= pthread.3 \
pthread_attr.3 \
pthread_attr_get_np.3 \
pthread_attr_setcreatesuspend_np.3 \
pthread_barrier_destroy.3 \
pthread_barrierattr.3 \
pthread_cancel.3 \
pthread_cleanup_pop.3 \
pthread_cleanup_push.3 \
@ -216,6 +218,12 @@ PTHREAD_MLINKS= pthread_attr.3 pthread_attr_destroy.3 \
pthread_attr.3 pthread_attr_setstack.3 \
pthread_attr.3 pthread_attr_setstackaddr.3 \
pthread_attr.3 pthread_attr_setstacksize.3
PTHREAD_MLINKS+=pthread_barrier_destroy.3 pthread_barrier_init.3 \
pthread_barrier_destroy.3 pthread_barrier_wait.3
PTHREAD_MLINKS+=pthread_barrierattr.3 pthread_barrierattr_destroy.3 \
pthread_barrierattr.3 pthread_barrierattr_getpshared.3 \
pthread_barrierattr.3 pthread_barrierattr_init.3 \
pthread_barrierattr.3 pthread_barrierattr_setpshared.3
PTHREAD_MLINKS+=pthread_condattr.3 pthread_condattr_destroy.3 \
pthread_condattr.3 pthread_condattr_init.3
PTHREAD_MLINKS+=pthread_getconcurrency.3 pthread_setconcurrency.3

157
share/man/man3/pthread_barrier_destroy.3 Normal file
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@ -0,0 +1,157 @@
.\" Copyright (c) 2004 Michael Telahun Makonnen
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.\" Note: The date here should be updated whenever a non-trivial
.\" change is made to the manual page.
.Dd February 19, 2004
.Dt PTHREAD_BARRIER_DESTROY 3 PTHREAD_BARRIER_INIT 3 PTHREAD_BARRIER_WAIT 3
.Os
.Sh NAME
.Nm pthread_barrier_destroy pthread_barrier_init pthread_barrier_wait
.Nd "destroy, initialize or wait on a barrier object"
.Sh LIBRARY
.Lb libpthread
.Lb libthr
.Sh SYNOPSIS
.In pthread.h
.Ft int
.Fn pthread_barrier_destroy "pthread_barrier_t *barrier"
.Ft int
.Fn pthread_barrier_init "pthread_barrier_t *barrier" "const pthread_barrierattr_t *attr" "int count"
.Ft int
.Fn pthread_barrier_wait "pthread_barrier_t *barrier"
.Sh DESCRIPTION
The
.Fn pthread_barrier_init
function will initialize
.Fa barrier
with attributes specified in
.Fa attr ,
or if it is NULL,
with default attributes.
The number of threads that must call
.Fn pthread_barrier_wait
before any of the waiting threads can be
released is specified by
.Fa count .
The
.Fn pthread_barrier_destroy
function will destroy
.Fa barrier
and release any resources that may have been allocated on its behalf.
.Pp
The
.Fn pthread_barrier_wait
function will synchronize calling threads at
.Fa barrier .
The threads will be blocked from
making further progress until
a sufficient number of threads calls this function.
The number of threads that must call it before
any of them will be released is determined by the
.Fa count
argument to
.Fn pthread_barrier_init .
Once the threads have been released the barrier will be reset.
.Sh DIAGNOSTICS
If successful,
both
.Fn pthread_barrier_destroy
and
.Fn pthread_barrier_init
will return zero.
Otherwise an error number will be returned to indicate the error.
If the call to
.Fn pthread_barrier_wait
is successful all but one of the threads will return zero.
That one thread will return PTHREAD_BARRIER_SERIAL_THREAD.
Otherwise an error number will be returned to indicate the error.
.Pp
None of these functions will return EINTR.
.Sh IMPLIMENTATION NOTES
In both
.Lb libpthread
and
.Lb libthr
the PTHREAD_BARRIER_SERIAL_THREAD return value will
always be returned by the last thread to reach the barrier.
.Sh ERRORS
The
.Fn pthread_barrier_destroy
function will fail if:
.Bl -tag -width Er
.It Bq Er EBUSY
An attempt was made to destroy
.Fa barrier
while it was in use.
.El
.Pp
The
.Fn pthread_barrier_destroy
and
.Fn pthread_barrier_wait
functions may fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified by
.Fa barrier
is invalid.
.El
.Pp
The
.Fn pthread_barrier_init
function will fail if:
.Bl -tag -width Er
.It Bq Er EAGAIN
The system lacks resources,
other than memory,
to initialize
.Fa barrier .
.It Bq Er EINVAL
The
.Fa count
argument is less than 1.
.It Bq Er ENOMEM
Insufficient memory to initialize
.Fa barrier .
.El
.Sh SEE ALSO
.Xr pthread_barrier_wait 3 ,
.Xr pthread_barrierattr 3
.Sh HISTORY
The
.Fn pthread_barrier_destroy ,
.Fn pthread_barrier_init
and
.Fn pthread_barrier_wait
functions first appeared in
.Lb libpthread
in
.Fx 5.2 ,
and in
.Lb libthr
in
.Fx 5.3 .

150
share/man/man3/pthread_barrierattr.3 Normal file
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@ -0,0 +1,150 @@
.\" Copyright (c) 2004 Michael Telahun Makonnen
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.\" Note: The date here should be updated whenever a non-trivial
.\" change is made to the manual page.
.Dd February 19, 2004
.Dt PTHREAD_BARRIERATTR_DESTROY 3 PTHREAD_BARRIERATTR_GETPSHARED 3 PTHREAD_BARRIERATTR_INIT 3 PTHREAD_BARRIERATTR_SETPSHARED 3
.Os
.Sh NAME
.Nm pthread_barrierattr_destroy pthread_barrierattr_getpshared
.Nm pthread_barrierattr_init pthread_barrierattr_setpshared
.Nd "manipulate a barrier attribute object"
.Sh LIBRARY
.Lb libpthread
.Lb libthr
.Sh SYNOPSIS
.In pthread.h
.Ft int
.Fn pthread_barrierattr_destroy "pthread_barrierattr_t *attr"
.Ft int
.Fn pthread_barrierattr_getpshared "const pthread_barrierattr_t *attr" "int *pshared"
.Ft int
.Fn pthread_barrierattr_init "pthread_barrierattr_t *attr"
.Ft int
.Fn pthread_barrierattr_setpshared "pthread_barrierattr_t *attr" "int pshared"
.Sh DESCRIPTION
The
.Fn pthread_barrierattr_init
function will initialize
.Fa attr
with default attributes.
The
.Fn pthread_barrierattr_destroy
function will destroy
.Fa attr
and release any resources that may have been allocated on its behalf.
.Pp
The
.Fn pthread_barrierattr_getpshared
function will put the value of the process-shared attribute from
.Fa attr
into the memory area pointed to by
.Fa pshared .
The
.Fn pthread_barrierattr_setpshared
function will set the process-shared attribute of
.Fa attr
to the value specified in
.Fa pshared.
The argument
.Fa pshared
may have one of the following values:
.Bl -tag -width ".Dv PTHREAD_PROCESS_PRIVATE"
.It Dv PTHREAD_PROCESS_PRIVATE
The barrier object it is attached to may only be accessed by
threads in the same process as the one that created the object.
.It Dv PTHREAD_PROCESS_SHARED
The barrier object it is attached to may be accessed by
threads in processes other than the one that created the object.
.El
.Sh DIAGNOSTICS
If successful all these functions will return zero.
Otherwise an error number will be returned to indicate the error.
.Pp
None of these functions will return EINTR.
.Pp
.Sh ERRORS
The
.Fn pthread_barrierattr_destroy ,
.Fn pthread_barrierattr_getpshared
and
.Fn pthread_barrierattr_setpshared
functions may fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified by
.Fa attr
is invalid.
.El
.Pp
The
.Fn pthread_barrierattr_init
function will fail if:
.Bl -tag -width Er
.It Bq Er ENOMEM
Insufficient memory to initialize the barrier attribute object
.Fa attr .
.El
.Pp
The
.Fn pthread_barrierattr_setpshared
function will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified in
.Fa pshared
is not one of the allowed values.
.El
.Sh SEE ALSO
.Xr pthread_barrier_destroy 3 ,
.Xr pthread_barrier_init 3 ,
.Xr pthread_barrier_wait 3 ,
.Sh HISTORY
The
.Fn pthread_barrierattr
functions first appeared in
.Lb libpthread
in
.Fx 5.2 ,
and in
.Lb libthr
in
.Fx 5.3 .
.Sh BUGS
The implementation of
.Fn pthread_barriers
does not fully conform to
.St -p1003.2
because the process-shared attribute is ignored in
.Lb libthr ,
and in
.Lb libpthread
if any value other than
.Dv PTHREAD_PROCESSES_PRIVATE
is specified in a call to
.Fn pthread_barrierattr_setpshared
it will return EINVAL.