commit 4ef0b463a56c19bad9197aa9f90d792090461429
author Glenn Kasten <gkasten@google.com> Wed Aug 14 13:52:27 2013 -0700
committer Glenn Kasten <gkasten@google.com> Thu Aug 15 10:18:27 2013 -0700
tree f601c1fd4510af2639696d8b04ebd03d9eee1dfb
parent 62cf1fda94a21e0efac1778c54a03672c122a23b

Fix race in checking exitPending() in RecordThread::threadLoop()

Change-Id: I97a1c5ab17a6c334d275be794392dcf6c9a88d0e

services/audioflinger/Threads.cpp

diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index c419807..a8854ca 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -4211,24 +4211,20 @@
     bool readOnce = false;
 
     // start recording
-    // FIXME Race here: exitPending could become true immediately after testing.
-    //       It is only set to true while mLock held, but we don't hold mLock yet.
-    //       Probably a benign race, but it would be safer to check exitPending with mLock held.
-    while (!exitPending()) {
+    for (;;) {
         Vector< sp<EffectChain> > effectChains;
 
         { // scope for mLock
             Mutex::Autolock _l(mLock);
+            if (exitPending()) {
+                break;
+            }
             processConfigEvents_l();
             // return value 'reconfig' is currently unused
             bool reconfig = checkForNewParameters_l();
             if (mActiveTrack == 0) {
                 standby();
-
-                if (exitPending()) {
-                    break;
-                }
-
+                // exitPending() can't become true here
                 releaseWakeLock_l();
                 ALOGV("RecordThread: loop stopping");
                 // go to sleep