DPDK  19.11.14-rc1
examples/performance-thread/common/lthread_cond.c
/*
* SPDX-License-Identifier: BSD-3-Clause
* Copyright 2015 Intel Corporation.
* Copyright 2012 Hasan Alayli <halayli@gmail.com>
*/
#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 <rte_string_fns.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)
strlcpy(c->name, "no name", sizeof(c->name));
else
strlcpy(c->name, name, sizeof(c->name));
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;
}