commit 0d09a9bec07b3bec78bd473ff0bfcf0a261f3f25
author Glenn Kasten <gkasten@google.com> Mon Jun 24 12:06:46 2013 -0700
committer Glenn Kasten <gkasten@google.com> Mon Jun 24 13:34:08 2013 -0700
tree 410d8c22e5d15f9143d04212cd96939c217cacc5
parent a2cf13c77260f98fc674f103dcbd2bb2488a80ce

Use mFutex as an event flag rather than semaphore

An event flag can be more fault-tolerant in case of loss of synchronization,
as it cannot overflow.  It also allows more bits to be used in the future.
See http://en.wikipedia.org/wiki/Event_flag

Change-Id: I01ca25d951eb263124da54bb4738f0d94ec4a48b

include/private/media/AudioTrackShared.h

diff --git a/include/private/media/AudioTrackShared.h b/include/private/media/AudioTrackShared.h
index 681f557..ef5bb8d 100644
--- a/include/private/media/AudioTrackShared.h
+++ b/include/private/media/AudioTrackShared.h
@@ -94,8 +94,9 @@
                                             // parameter
                                             // renamed to "_" to detect incorrect use
 
-    volatile    int32_t     mFutex;     // semaphore: down (P) by client,
+    volatile    int32_t     mFutex;     // event flag: down (P) by client,
                                         // up (V) by server or binderDied() or interrupt()
+#define CBLK_FUTEX_WAKE 1               // if event flag bit is set, then a deferred wake is pending
 
 private: