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openmpi/opal/mca/threads/qthreads/threads_qthreads_mutex.c
Shintaro Iwasaki 919a16300c mca/threads/qthreads: implement missing functionalities
Signed-off-by: Shintaro Iwasaki <siwasaki@anl.gov>
2020-10-05 11:39:18 -05:00

140 строки
4.0 KiB
C

/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil -*- */
/*
* Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2005 The University of Tennessee and The University
* of Tennessee Research Foundation. All rights
* reserved.
* Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
* University of Stuttgart. All rights reserved.
* Copyright (c) 2004-2005 The Regents of the University of California.
* All rights reserved.
* Copyright (c) 2007-2016 Los Alamos National Security, LLC. All rights
* reserved.
* Copyright (c) 2015 Research Organization for Information Science
* and Technology (RIST). All rights reserved.
* Copyright (c) 2019 Sandia National Laboratories. All rights reserved.
*
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#include "opal_config.h"
#include "opal/mca/threads/mutex.h"
#include "opal/constants.h"
/*
* Wait and see if some upper layer wants to use threads, if support
* exists.
*/
bool opal_uses_threads = false;
static void opal_mutex_construct(opal_mutex_t *m)
{
opal_threads_ensure_init_qthreads();
opal_mutex_create(m);
}
static void opal_mutex_destruct(opal_mutex_t *m)
{
}
OBJ_CLASS_INSTANCE(opal_mutex_t,
opal_object_t,
opal_mutex_construct,
opal_mutex_destruct);
static void opal_recursive_mutex_construct(opal_recursive_mutex_t *m)
{
}
OBJ_CLASS_INSTANCE(opal_recursive_mutex_t,
opal_object_t,
opal_recursive_mutex_construct,
opal_mutex_destruct);
int opal_cond_init(opal_cond_t *cond)
{
opal_atomic_lock_init(&cond->m_lock, 0);
cond->m_waiter_head = NULL;
cond->m_waiter_tail = NULL;
return OPAL_SUCCESS;
}
typedef struct {
int m_signaled;
void *m_prev;
} cond_waiter_t;
int opal_cond_wait(opal_cond_t *cond, opal_mutex_t *lock)
{
opal_threads_ensure_init_qthreads();
/* This thread is taking "lock", so only this thread can access this
* condition variable. */
opal_atomic_lock(&cond->m_lock);
cond_waiter_t waiter = { 0, NULL };
if (NULL == cond->m_waiter_head) {
cond->m_waiter_tail = (void *)&waiter;
} else {
((cond_waiter_t *)cond->m_waiter_head)->m_prev = (void *)&waiter;
}
cond->m_waiter_head = (void *)&waiter;
opal_atomic_unlock(&cond->m_lock);
while (1) {
opal_mutex_unlock(lock);
qthread_yield();
opal_mutex_lock(lock);
/* Check if someone woke me up. */
opal_atomic_lock(&cond->m_lock);
int signaled = waiter.m_signaled;
opal_atomic_unlock(&cond->m_lock);
if (1 == signaled) {
break;
}
/* Unlock the lock again. */
}
return OPAL_SUCCESS;
}
int opal_cond_broadcast(opal_cond_t *cond)
{
opal_atomic_lock(&cond->m_lock);
while (NULL != cond->m_waiter_tail) {
cond_waiter_t *p_cur_tail = (cond_waiter_t *)cond->m_waiter_tail;
cond->m_waiter_tail = p_cur_tail->m_prev;
/* Awaken one of threads in a FIFO manner. */
p_cur_tail->m_signaled = 1;
}
/* No waiters. */
cond->m_waiter_head = NULL;
opal_atomic_unlock(&cond->m_lock);
return OPAL_SUCCESS;
}
int opal_cond_signal(opal_cond_t *cond)
{
opal_atomic_lock(&cond->m_lock);
if (NULL != cond->m_waiter_tail) {
cond_waiter_t *p_cur_tail = (cond_waiter_t *)cond->m_waiter_tail;
cond->m_waiter_tail = p_cur_tail->m_prev;
/* Awaken one of threads. */
p_cur_tail->m_signaled = 1;
if (NULL == cond->m_waiter_tail) {
cond->m_waiter_head = NULL;
}
}
opal_atomic_unlock(&cond->m_lock);
return OPAL_SUCCESS;
}
int opal_cond_destroy(opal_cond_t *cond)
{
return OPAL_SUCCESS;
}