coroutine: add qemu_co_queue_restart_all()

It's common to wake up all waiting coroutines.  Introduce the
qemu_co_queue_restart_all() function to do this instead of looping over
qemu_co_queue_next() in every caller.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2011-11-17 13:40:26 +00:00 committed by Kevin Wolf
parent 3951690a4a
commit e8ee5e4c47
3 changed files with 14 additions and 8 deletions

View File

@ -516,7 +516,7 @@ static void run_dependent_requests(BDRVQcowState *s, QCowL2Meta *m)
/* Restart all dependent requests */
if (!qemu_co_queue_empty(&m->dependent_requests)) {
qemu_co_mutex_unlock(&s->lock);
while(qemu_co_queue_next(&m->dependent_requests));
qemu_co_queue_restart_all(&m->dependent_requests);
qemu_co_mutex_lock(&s->lock);
}
}

View File

@ -84,6 +84,13 @@ bool qemu_co_queue_next(CoQueue *queue)
return (next != NULL);
}
void qemu_co_queue_restart_all(CoQueue *queue)
{
while (qemu_co_queue_next(queue)) {
/* Do nothing */
}
}
bool qemu_co_queue_empty(CoQueue *queue)
{
return (QTAILQ_FIRST(&queue->entries) == NULL);
@ -144,13 +151,7 @@ void qemu_co_rwlock_unlock(CoRwlock *lock)
assert(qemu_in_coroutine());
if (lock->writer) {
lock->writer = false;
while (!qemu_co_queue_empty(&lock->queue)) {
/*
* Wakeup every body. This will include some
* writers too.
*/
qemu_co_queue_next(&lock->queue);
}
qemu_co_queue_restart_all(&lock->queue);
} else {
lock->reader--;
assert(lock->reader >= 0);

View File

@ -130,6 +130,11 @@ void coroutine_fn qemu_co_queue_wait_insert_head(CoQueue *queue);
*/
bool qemu_co_queue_next(CoQueue *queue);
/**
* Restarts all coroutines in the CoQueue and leaves the queue empty.
*/
void qemu_co_queue_restart_all(CoQueue *queue);
/**
* Checks if the CoQueue is empty.
*/