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>

1 files changed, 8 insertions, 7 deletions

diff --git a/qemu-coroutine-lock.c b/qemu-coroutine-lock.c
index 9549c07..26ad76b 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);