+
+void qemu_co_rwlock_init(CoRwlock *lock)
+{
+ memset(lock, 0, sizeof(*lock));
+ qemu_co_queue_init(&lock->queue);
+}
+
+void qemu_co_rwlock_rdlock(CoRwlock *lock)
+{
+ while (lock->writer) {
+ qemu_co_queue_wait(&lock->queue);
+ }
+ lock->reader++;
+}
+
+void qemu_co_rwlock_unlock(CoRwlock *lock)
+{
+ assert(qemu_in_coroutine());
+ if (lock->writer) {
+ lock->writer = false;
+ qemu_co_queue_restart_all(&lock->queue);
+ } else {
+ lock->reader--;
+ assert(lock->reader >= 0);
+ /* Wakeup only one waiting writer */
+ if (!lock->reader) {
+ qemu_co_queue_next(&lock->queue);
+ }
+ }
+}
+
+void qemu_co_rwlock_wrlock(CoRwlock *lock)
+{
+ while (lock->writer || lock->reader) {
+ qemu_co_queue_wait(&lock->queue);
+ }
+ lock->writer = true;
+}