/*
* 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;
}
/*
* 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);
RTE_ASSERT(unblocked->sched != NULL);
_ready_queue_insert((struct lthread_sched *)
unblocked->sched, unblocked);
break;
}
}
/* release the lock */
m->owner = NULL;
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;
}
/*
* Create a key
* this means getting a key from the the pool
*/
int lthread_key_create(unsigned int *key, tls_destructor_func destructor)
{
if (key == NULL)
return POSIX_ERRNO(EINVAL);
struct lthread_key *new_key;
if (rte_ring_mc_dequeue((struct rte_ring *)key_pool, (void **)&new_key)
== 0) {
new_key->destructor = destructor;
*key = (new_key - key_table);
return 0;
}
return POSIX_ERRNO(EAGAIN);
}
/*
* 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;
}
/*
* 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 */
}
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;
}
/* try to lock a mutex but don't 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);
}
/*
* migrate the current thread to another scheduler running
* on the specified lcore.
*/
int lthread_set_affinity(unsigned lcoreid)
{
struct lthread *lt = THIS_LTHREAD;
struct lthread_sched *dest_sched;
if (unlikely(lcoreid >= LTHREAD_MAX_LCORES))
return POSIX_ERRNO(EINVAL);
DIAG_EVENT(lt, LT_DIAG_LTHREAD_AFFINITY, lcoreid, 0);
dest_sched = schedcore[lcoreid];
if (unlikely(dest_sched == NULL))
return POSIX_ERRNO(EINVAL);
if (likely(dest_sched != THIS_SCHED)) {
lt->sched = dest_sched;
lt->pending_wr_queue = dest_sched->pready;
_affinitize();
return 0;
}
return 0;
}
/*
* Delete a key
*/
int lthread_key_delete(unsigned int k)
{
struct lthread_key *key;
key = (struct lthread_key *) &key_table[k];
if (k > LTHREAD_MAX_KEYS)
return POSIX_ERRNO(EINVAL);
key->destructor = NULL;
rte_ring_mp_enqueue((struct rte_ring *)key_pool,
(void *)key);
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;
}
/*
* 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;
}
/*
* Set a value against a key
* If the key is no longer valid return an error
* when storing value
*/
int lthread_setspecific(unsigned int k, const void *data)
{
if (k > LTHREAD_MAX_KEYS)
return POSIX_ERRNO(EINVAL);
int n = THIS_LTHREAD->tls->nb_keys_inuse;
/* discard const qualifier */
char *p = (char *) (uintptr_t) data;
if (data != NULL) {
if (THIS_LTHREAD->tls->data[k] == NULL)
THIS_LTHREAD->tls->nb_keys_inuse = n+1;
}
THIS_LTHREAD->tls->data[k] = (void *) p;
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);
}
