--- /dev/null
+/*-
+ * 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.
+ */
+
+#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 <rte_per_lcore.h>
+#include <rte_log.h>
+#include <rte_spinlock.h>
+#include <rte_common.h>
+
+#include "lthread_api.h"
+#include "lthread_int.h"
+#include "lthread_mutex.h"
+#include "lthread_sched.h"
+#include "lthread_queue.h"
+#include "lthread_objcache.h"
+#include "lthread_diag.h"
+
+/*
+ * Create a mutex
+ */
+int
+lthread_mutex_init(char *name, struct lthread_mutex **mutex,
+ __rte_unused const struct lthread_mutexattr *attr)
+{
+ struct lthread_mutex *m;
+
+ if (mutex == NULL)
+ return POSIX_ERRNO(EINVAL);
+
+
+ m = _lthread_objcache_alloc((THIS_SCHED)->mutex_cache);
+ if (m == NULL)
+ return POSIX_ERRNO(EAGAIN);
+
+ m->blocked = _lthread_queue_create("blocked queue");
+ if (m->blocked == NULL) {
+ _lthread_objcache_free((THIS_SCHED)->mutex_cache, m);
+ return POSIX_ERRNO(EAGAIN);
+ }
+
+ if (name == NULL)
+ strncpy(m->name, "no name", sizeof(m->name));
+ else
+ strncpy(m->name, name, sizeof(m->name));
+ m->name[sizeof(m->name)-1] = 0;
+
+ m->root_sched = THIS_SCHED;
+ m->owner = NULL;
+
+ rte_atomic64_init(&m->count);
+
+ DIAG_CREATE_EVENT(m, LT_DIAG_MUTEX_CREATE);
+ /* success */
+ (*mutex) = m;
+ return 0;
+}
+
+/*
+ * Destroy a mutex
+ */
+int lthread_mutex_destroy(struct lthread_mutex *m)
+{
+ if ((m == NULL) || (m->blocked == NULL)) {
+ DIAG_EVENT(m, LT_DIAG_MUTEX_DESTROY, m, POSIX_ERRNO(EINVAL));
+ return POSIX_ERRNO(EINVAL);
+ }
+
+ if (m->owner == NULL) {
+ /* try to delete the blocked queue */
+ if (_lthread_queue_destroy(m->blocked) < 0) {
+ DIAG_EVENT(m, LT_DIAG_MUTEX_DESTROY,
+ m, POSIX_ERRNO(EBUSY));
+ return POSIX_ERRNO(EBUSY);
+ }
+
+ /* free the mutex to cache */
+ _lthread_objcache_free(m->root_sched->mutex_cache, m);
+ DIAG_EVENT(m, LT_DIAG_MUTEX_DESTROY, m, 0);
+ return 0;
+ }
+ /* can't do its still in use */
+ DIAG_EVENT(m, LT_DIAG_MUTEX_DESTROY, m, POSIX_ERRNO(EBUSY));
+ return POSIX_ERRNO(EBUSY);
+}
+
+/*
+ * Try to obtain a mutex
+ */
+int lthread_mutex_lock(struct lthread_mutex *m)
+{
+ struct lthread *lt = THIS_LTHREAD;
+
+ if ((m == NULL) || (m->blocked == NULL)) {
+ DIAG_EVENT(m, LT_DIAG_MUTEX_LOCK, m, POSIX_ERRNO(EINVAL));
+ return POSIX_ERRNO(EINVAL);
+ }
+
+ /* allow no recursion */
+ if (m->owner == lt) {
+ DIAG_EVENT(m, LT_DIAG_MUTEX_LOCK, m, POSIX_ERRNO(EDEADLK));
+ return POSIX_ERRNO(EDEADLK);
+ }
+
+ for (;;) {
+ rte_atomic64_inc(&m->count);
+ do {
+ if (rte_atomic64_cmpset
+ ((uint64_t *) &m->owner, 0, (uint64_t) lt)) {
+ /* happy days, we got the lock */
+ DIAG_EVENT(m, LT_DIAG_MUTEX_LOCK, m, 0);
+ return 0;
+ }
+ /* spin due to race with unlock when
+ * nothing was blocked
+ */
+ } while ((rte_atomic64_read(&m->count) == 1) &&
+ (m->owner == NULL));
+
+ /* queue the current thread in the blocked queue
+ * we defer this to after we return to the scheduler
+ * to ensure that the current thread context is saved
+ * before unlock could result in it being dequeued and
+ * resumed
+ */
+ DIAG_EVENT(m, LT_DIAG_MUTEX_BLOCKED, m, lt);
+ lt->pending_wr_queue = m->blocked;
+ /* now relinquish cpu */
+ _suspend();
+ /* resumed, must loop and compete for the lock again */
+ }
+ LTHREAD_ASSERT(0);
+ return 0;
+}
+
+/* try to lock a mutex but dont block */
+int lthread_mutex_trylock(struct lthread_mutex *m)
+{
+ struct lthread *lt = THIS_LTHREAD;
+
+ if ((m == NULL) || (m->blocked == NULL)) {
+ DIAG_EVENT(m, LT_DIAG_MUTEX_TRYLOCK, m, POSIX_ERRNO(EINVAL));
+ return POSIX_ERRNO(EINVAL);
+ }
+
+ if (m->owner == lt) {
+ /* no recursion */
+ DIAG_EVENT(m, LT_DIAG_MUTEX_TRYLOCK, m, POSIX_ERRNO(EDEADLK));
+ return POSIX_ERRNO(EDEADLK);
+ }
+
+ rte_atomic64_inc(&m->count);
+ if (rte_atomic64_cmpset
+ ((uint64_t *) &m->owner, (uint64_t) NULL, (uint64_t) lt)) {
+ /* got the lock */
+ DIAG_EVENT(m, LT_DIAG_MUTEX_TRYLOCK, m, 0);
+ return 0;
+ }
+
+ /* failed so return busy */
+ rte_atomic64_dec(&m->count);
+ DIAG_EVENT(m, LT_DIAG_MUTEX_TRYLOCK, m, POSIX_ERRNO(EBUSY));
+ return POSIX_ERRNO(EBUSY);
+}
+
+/*
+ * Unlock a mutex
+ */
+int lthread_mutex_unlock(struct lthread_mutex *m)
+{
+ struct lthread *lt = THIS_LTHREAD;
+ struct lthread *unblocked;
+
+ if ((m == NULL) || (m->blocked == NULL)) {
+ DIAG_EVENT(m, LT_DIAG_MUTEX_UNLOCKED, m, POSIX_ERRNO(EINVAL));
+ return POSIX_ERRNO(EINVAL);
+ }
+
+ /* fail if its owned */
+ if (m->owner != lt || m->owner == NULL) {
+ DIAG_EVENT(m, LT_DIAG_MUTEX_UNLOCKED, m, POSIX_ERRNO(EPERM));
+ return POSIX_ERRNO(EPERM);
+ }
+
+ rte_atomic64_dec(&m->count);
+ /* if there are blocked threads then make one ready */
+ while (rte_atomic64_read(&m->count) > 0) {
+ unblocked = _lthread_queue_remove(m->blocked);
+
+ if (unblocked != NULL) {
+ rte_atomic64_dec(&m->count);
+ DIAG_EVENT(m, LT_DIAG_MUTEX_UNLOCKED, m, unblocked);
+ LTHREAD_ASSERT(unblocked->sched != NULL);
+ _ready_queue_insert((struct lthread_sched *)
+ unblocked->sched, unblocked);
+ break;
+ }
+ }
+ /* release the lock */
+ m->owner = NULL;
+ return 0;
+}
+
+/*
+ * return the diagnostic ref val stored in a mutex
+ */
+uint64_t
+lthread_mutex_diag_ref(struct lthread_mutex *m)
+{
+ if (m == NULL)
+ return 0;
+ return m->diag_ref;
+}
Code Review / deb_dpdk.git / blobdiff