diff --git a/thread-pool.c b/thread-pool.c
index 7895544..72be971 100644
--- a/thread-pool.c
+++ b/thread-pool.c
@@ -71,20 +72,16 @@ static void *worker_thread(void *unused)
         ThreadPoolElement *req;
         int ret;
 
-        qemu_mutex_lock(&lock);
-        idle_threads++;
-        qemu_mutex_unlock(&lock);
-        ret = qemu_sem_timedwait(&sem, 10000);
-        qemu_mutex_lock(&lock);
-        idle_threads--;
+        atomic_inc(&idle_threads);
+        do {
+            ret = qemu_sem_timedwait(&sem, 10000);
+        } while (ret == -1 && atomic_read(&QTAILQ_FIRST(&request_list)) != NULL);
+        atomic_dec(&idle_threads);
         if (ret == -1) {
-            if (QTAILQ_EMPTY(&request_list)) {
-                break;
-            }
-            qemu_mutex_unlock(&lock);
-            continue;
+            break;
         }
 
+        qemu_mutex_lock(&lock);
         req = QTAILQ_FIRST(&request_list);
         QTAILQ_REMOVE(&request_list, req, reqs);
         req->state = THREAD_ACTIVE;
@@ -226,7 +223,7 @@ BlockDriverAIOCB *thread_pool_submit_aio(ThreadPoolFunc *func, void *arg,
     trace_thread_pool_submit(req, arg);
 
     qemu_mutex_lock(&lock);
-    if (idle_threads == 0 && cur_threads < max_threads) {
+    if (atomic_read(&idle_threads) == 0 && cur_threads < max_threads) {
         spawn_thread();
     }
     QTAILQ_INSERT_TAIL(&request_list, req, reqs);