QThreadPool: fix race on 'queue' in stealRunnable()

The code under mutex protection already implicitly handles the case where
queue.empty(), so just removing the pre-lock check suffices.

Change-Id: I01467aff62e61bb4efd16359dd64546ff51c6bad
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

diff --git a/src/corelib/thread/qthreadpool.cpp b/src/corelib/thread/qthreadpool.cpp
index a923b8a..1c3672b 100644 (file)
--- a/src/corelib/thread/qthreadpool.cpp
+++ b/src/corelib/thread/qthreadpool.cpp
@@ -314,7 +314,7 @@ bool QThreadPoolPrivate::waitForDone(int msecs)
 */
 void QThreadPoolPrivate::stealRunnable(QRunnable *runnable)
 {
-    if (runnable == 0 || queue.isEmpty())
+    if (runnable == 0)
         return;
     bool found = false;
     {