242 lines
6.3 KiB
C
242 lines
6.3 KiB
C
/* $NetBSD: pthread_barrier.c,v 1.6 2003/03/08 08:03:35 lukem Exp $ */
|
|
|
|
/*-
|
|
* Copyright (c) 2001, 2003 The NetBSD Foundation, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to The NetBSD Foundation
|
|
* by Nathan J. Williams, and by Jason R. Thorpe.
|
|
*
|
|
* 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.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the NetBSD
|
|
* Foundation, Inc. and its contributors.
|
|
* 4. Neither the name of The NetBSD Foundation nor the names of its
|
|
* contributors may be used to endorse or promote products derived
|
|
* from this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__RCSID("$NetBSD: pthread_barrier.c,v 1.6 2003/03/08 08:03:35 lukem Exp $");
|
|
|
|
#include <errno.h>
|
|
#include <sys/cdefs.h>
|
|
|
|
#include "pthread.h"
|
|
#include "pthread_int.h"
|
|
|
|
#undef PTHREAD_BARRIER_DEBUG
|
|
|
|
#ifdef PTHREAD_BARRIER_DEBUG
|
|
#define SDPRINTF(x) DPRINTF(x)
|
|
#else
|
|
#define SDPRINTF(x)
|
|
#endif
|
|
|
|
int
|
|
pthread_barrier_init(pthread_barrier_t *barrier,
|
|
const pthread_barrierattr_t *attr, unsigned int count)
|
|
{
|
|
pthread_t self;
|
|
|
|
#ifdef ERRORCHECK
|
|
if ((barrier == NULL) ||
|
|
(attr && (attr->ptba_magic != _PT_BARRIERATTR_MAGIC)))
|
|
return EINVAL;
|
|
#endif
|
|
|
|
if (count == 0)
|
|
return EINVAL;
|
|
|
|
self = pthread__self();
|
|
|
|
if (barrier->ptb_magic == _PT_BARRIER_MAGIC) {
|
|
/*
|
|
* We're simply reinitializing the barrier to a
|
|
* new count.
|
|
*/
|
|
pthread_spinlock(self, &barrier->ptb_lock);
|
|
|
|
if (barrier->ptb_magic != _PT_BARRIER_MAGIC) {
|
|
pthread_spinunlock(self, &barrier->ptb_lock);
|
|
return EINVAL;
|
|
}
|
|
|
|
if (!PTQ_EMPTY(&barrier->ptb_waiters)) {
|
|
pthread_spinunlock(self, &barrier->ptb_lock);
|
|
return EBUSY;
|
|
}
|
|
|
|
barrier->ptb_initcount = count;
|
|
barrier->ptb_curcount = 0;
|
|
barrier->ptb_generation = 0;
|
|
|
|
pthread_spinunlock(self, &barrier->ptb_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
barrier->ptb_magic = _PT_BARRIER_MAGIC;
|
|
pthread_lockinit(&barrier->ptb_lock);
|
|
PTQ_INIT(&barrier->ptb_waiters);
|
|
barrier->ptb_initcount = count;
|
|
barrier->ptb_curcount = 0;
|
|
barrier->ptb_generation = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
int
|
|
pthread_barrier_destroy(pthread_barrier_t *barrier)
|
|
{
|
|
pthread_t self;
|
|
|
|
#ifdef ERRORCHECK
|
|
if ((barrier == NULL) || (barrier->ptb_magic != _PT_BARRIER_MAGIC))
|
|
return EINVAL;
|
|
#endif
|
|
|
|
self = pthread__self();
|
|
|
|
pthread_spinlock(self, &barrier->ptb_lock);
|
|
|
|
if (barrier->ptb_magic != _PT_BARRIER_MAGIC) {
|
|
pthread_spinunlock(self, &barrier->ptb_lock);
|
|
return EINVAL;
|
|
}
|
|
|
|
if (!PTQ_EMPTY(&barrier->ptb_waiters)) {
|
|
pthread_spinunlock(self, &barrier->ptb_lock);
|
|
return EBUSY;
|
|
}
|
|
|
|
barrier->ptb_magic = _PT_BARRIER_DEAD;
|
|
|
|
pthread_spinunlock(self, &barrier->ptb_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
int
|
|
pthread_barrier_wait(pthread_barrier_t *barrier)
|
|
{
|
|
pthread_t self;
|
|
unsigned int gen;
|
|
|
|
#ifdef ERRORCHECK
|
|
if ((barrier == NULL) || (barrier->ptb_magic != _PT_BARRIER_MAGIC))
|
|
return EINVAL;
|
|
#endif
|
|
self = pthread__self();
|
|
|
|
pthread_spinlock(self, &barrier->ptb_lock);
|
|
|
|
/*
|
|
* A single arbitrary thread is supposed to return
|
|
* PTHREAD_BARRIER_SERIAL_THREAD, and everone else
|
|
* is supposed to return 0. Since pthread_barrier_wait()
|
|
* is not a cancellation point, this is trivial; we
|
|
* simply elect that the thread that causes the barrier
|
|
* to be satisfied gets the special return value. Note
|
|
* that this final thread does not actually need to block,
|
|
* but instead is responsible for waking everyone else up.
|
|
*/
|
|
if (barrier->ptb_curcount + 1 == barrier->ptb_initcount) {
|
|
struct pthread_queue_t blockedq;
|
|
|
|
SDPRINTF(("(barrier wait %p) Satisfied %p\n",
|
|
self, barrier));
|
|
|
|
blockedq = barrier->ptb_waiters;
|
|
PTQ_INIT(&barrier->ptb_waiters);
|
|
barrier->ptb_curcount = 0;
|
|
barrier->ptb_generation++;
|
|
|
|
pthread__sched_sleepers(self, &blockedq);
|
|
|
|
pthread_spinunlock(self, &barrier->ptb_lock);
|
|
|
|
return PTHREAD_BARRIER_SERIAL_THREAD;
|
|
}
|
|
|
|
barrier->ptb_curcount++;
|
|
gen = barrier->ptb_generation;
|
|
while (gen == barrier->ptb_generation) {
|
|
SDPRINTF(("(barrier wait %p) Waiting on %p\n",
|
|
self, barrier));
|
|
|
|
pthread_spinlock(self, &self->pt_statelock);
|
|
|
|
self->pt_state = PT_STATE_BLOCKED_QUEUE;
|
|
self->pt_sleepobj = barrier;
|
|
self->pt_sleepq = &barrier->ptb_waiters;
|
|
self->pt_sleeplock = &barrier->ptb_lock;
|
|
|
|
pthread_spinunlock(self, &self->pt_statelock);
|
|
|
|
PTQ_INSERT_TAIL(&barrier->ptb_waiters, self, pt_sleep);
|
|
|
|
pthread__block(self, &barrier->ptb_lock);
|
|
SDPRINTF(("(barrier wait %p) Woke up on %p\n",
|
|
self, barrier));
|
|
/* Spinlock is unlocked on return */
|
|
pthread_spinlock(self, &barrier->ptb_lock);
|
|
}
|
|
pthread_spinunlock(self, &barrier->ptb_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
int
|
|
pthread_barrierattr_init(pthread_barrierattr_t *attr)
|
|
{
|
|
|
|
#ifdef ERRORCHECK
|
|
if (attr == NULL)
|
|
return EINVAL;
|
|
#endif
|
|
|
|
attr->ptba_magic = _PT_BARRIERATTR_MAGIC;
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
int
|
|
pthread_barrierattr_destroy(pthread_barrierattr_t *attr)
|
|
{
|
|
|
|
#ifdef ERRORCHECK
|
|
if ((attr == NULL) ||
|
|
(attr->ptba_magic != _PT_BARRIERATTR_MAGIC))
|
|
return EINVAL;
|
|
#endif
|
|
|
|
attr->ptba_magic = _PT_BARRIERATTR_DEAD;
|
|
|
|
return 0;
|
|
}
|