From e8ee5e4c476d5b0654d8f1271a2b7c065acc486e Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Thu, 17 Nov 2011 13:40:26 +0000 Subject: 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 Signed-off-by: Kevin Wolf --- block/qcow2.c | 2 +- qemu-coroutine-lock.c | 15 ++++++++------- qemu-coroutine.h | 5 +++++ 3 files changed, 14 insertions(+), 8 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index 5ac9fb4828..a2be7d7949 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -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); } } diff --git a/qemu-coroutine-lock.c b/qemu-coroutine-lock.c index 9549c075ee..26ad76bf50 100644 --- a/qemu-coroutine-lock.c +++ b/qemu-coroutine-lock.c @@ -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); diff --git a/qemu-coroutine.h b/qemu-coroutine.h index 8a2e5d2a10..8a55fe125e 100644 --- a/qemu-coroutine.h +++ b/qemu-coroutine.h @@ -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. */ -- cgit v1.2.3