DPDK  16.11.11
performance-thread/common/lthread_cond.c
/*-
* BSD LICENSE
*
* Copyright(c) 2015 Intel Corporation. All rights reserved.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of Intel Corporation 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 COPYRIGHT HOLDERS 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 COPYRIGHT
* OWNER 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.
*/
/*
* Some portions of this software may have been derived from the
* https://github.com/halayli/lthread which carrys the following license.
*
* Copyright (C) 2012, Hasan Alayli <halayli@gmail.com>
*
* 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 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 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.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <stddef.h>
#include <limits.h>
#include <inttypes.h>
#include <unistd.h>
#include <pthread.h>
#include <fcntl.h>
#include <sys/time.h>
#include <sys/mman.h>
#include <errno.h>
#include <rte_log.h>
#include <rte_common.h>
#include "lthread_api.h"
#include "lthread_diag_api.h"
#include "lthread_diag.h"
#include "lthread_int.h"
#include "lthread_sched.h"
#include "lthread_queue.h"
#include "lthread_objcache.h"
#include "lthread_timer.h"
#include "lthread_mutex.h"
#include "lthread_cond.h"
/*
* Create a condition variable
*/
int
lthread_cond_init(char *name, struct lthread_cond **cond,
__rte_unused const struct lthread_condattr *attr)
{
struct lthread_cond *c;
if (cond == NULL)
return POSIX_ERRNO(EINVAL);
/* allocate a condition variable from cache */
c = _lthread_objcache_alloc((THIS_SCHED)->cond_cache);
if (c == NULL)
return POSIX_ERRNO(EAGAIN);
c->blocked = _lthread_queue_create("blocked");
if (c->blocked == NULL) {
_lthread_objcache_free((THIS_SCHED)->cond_cache, (void *)c);
return POSIX_ERRNO(EAGAIN);
}
if (name == NULL)
strncpy(c->name, "no name", sizeof(c->name));
else
strncpy(c->name, name, sizeof(c->name));
c->name[sizeof(c->name)-1] = 0;
c->root_sched = THIS_SCHED;
(*cond) = c;
DIAG_CREATE_EVENT((*cond), LT_DIAG_COND_CREATE);
return 0;
}
/*
* Destroy a condition variable
*/
int lthread_cond_destroy(struct lthread_cond *c)
{
if (c == NULL) {
DIAG_EVENT(c, LT_DIAG_COND_DESTROY, c, POSIX_ERRNO(EINVAL));
return POSIX_ERRNO(EINVAL);
}
/* try to free it */
if (_lthread_queue_destroy(c->blocked) < 0) {
/* queue in use */
DIAG_EVENT(c, LT_DIAG_COND_DESTROY, c, POSIX_ERRNO(EBUSY));
return POSIX_ERRNO(EBUSY);
}
/* okay free it */
_lthread_objcache_free(c->root_sched->cond_cache, c);
DIAG_EVENT(c, LT_DIAG_COND_DESTROY, c, 0);
return 0;
}
/*
* Wait on a condition variable
*/
int lthread_cond_wait(struct lthread_cond *c, __rte_unused uint64_t reserved)
{
struct lthread *lt = THIS_LTHREAD;
if (c == NULL) {
DIAG_EVENT(c, LT_DIAG_COND_WAIT, c, POSIX_ERRNO(EINVAL));
return POSIX_ERRNO(EINVAL);
}
DIAG_EVENT(c, LT_DIAG_COND_WAIT, c, 0);
/* queue the current thread in the blocked queue
* this will be written when we return to the scheduler
* to ensure that the current thread context is saved
* before any signal could result in it being dequeued and
* resumed
*/
lt->pending_wr_queue = c->blocked;
_suspend();
/* the condition happened */
return 0;
}
/*
* Signal a condition variable
* attempt to resume any blocked thread
*/
int lthread_cond_signal(struct lthread_cond *c)
{
struct lthread *lt;
if (c == NULL) {
DIAG_EVENT(c, LT_DIAG_COND_SIGNAL, c, POSIX_ERRNO(EINVAL));
return POSIX_ERRNO(EINVAL);
}
lt = _lthread_queue_remove(c->blocked);
if (lt != NULL) {
/* okay wake up this thread */
DIAG_EVENT(c, LT_DIAG_COND_SIGNAL, c, lt);
_ready_queue_insert((struct lthread_sched *)lt->sched, lt);
}
return 0;
}
/*
* Broadcast a condition variable
*/
int lthread_cond_broadcast(struct lthread_cond *c)
{
struct lthread *lt;
if (c == NULL) {
DIAG_EVENT(c, LT_DIAG_COND_BROADCAST, c, POSIX_ERRNO(EINVAL));
return POSIX_ERRNO(EINVAL);
}
DIAG_EVENT(c, LT_DIAG_COND_BROADCAST, c, 0);
do {
/* drain the queue waking everybody */
lt = _lthread_queue_remove(c->blocked);
if (lt != NULL) {
DIAG_EVENT(c, LT_DIAG_COND_BROADCAST, c, lt);
/* wake up */
_ready_queue_insert((struct lthread_sched *)lt->sched,
lt);
}
} while (!_lthread_queue_empty(c->blocked));
_reschedule();
DIAG_EVENT(c, LT_DIAG_COND_BROADCAST, c, 0);
return 0;
}
/*
* return the diagnostic ref val stored in a condition var
*/
uint64_t
lthread_cond_diag_ref(struct lthread_cond *c)
{
if (c == NULL)
return 0;
return c->diag_ref;
}