commit 84f5278a36f2816cc38f64307b4a1ad8a6818507
author Lajos Molnar <lajos@google.com> Thu Sep 11 10:01:55 2014 -0700
committer Lajos Molnar <lajos@google.com> Thu Sep 11 14:02:11 2014 -0700
tree a70b12822e0c000bef10379a6938889fd59ed933
parent 7c12b0358b6d3b66e231fe4a67bb55f424b3857e

avoid kWhatReadBuffer message spam in GenericSource

When playig WVM video, an extra readBuffer is posted for each
dequeueAccessUnit, resulting in an unbounded number of messages.

Bug: 17472979
Change-Id: Ice92ccf2454bf7a70856a4a8b535cefffc9e61ac

media/libmediaplayerservice/nuplayer/GenericSource.cpp

diff --git a/media/libmediaplayerservice/nuplayer/GenericSource.cpp b/media/libmediaplayerservice/nuplayer/GenericSource.cpp
index 8e1987a..ec1a9a0 100644
--- a/media/libmediaplayerservice/nuplayer/GenericSource.cpp
+++ b/media/libmediaplayerservice/nuplayer/GenericSource.cpp
@@ -54,7 +54,8 @@
       mDrmManagerClient(NULL),
       mMetaDataSize(-1ll),
       mBitrate(-1ll),
-      mPollBufferingGeneration(0) {
+      mPollBufferingGeneration(0),
+      mPendingReadBufferTypes(0) {
     resetDataSource();
     DataSource::RegisterDefaultSniffers();
 }
@@ -1148,15 +1149,27 @@
 }
 
 void NuPlayer::GenericSource::postReadBuffer(media_track_type trackType) {
-    sp<AMessage> msg = new AMessage(kWhatReadBuffer, id());
-    msg->setInt32("trackType", trackType);
-    msg->post();
+    Mutex::Autolock _l(mReadBufferLock);
+
+    if ((mPendingReadBufferTypes & (1 << trackType)) == 0) {
+        mPendingReadBufferTypes |= (1 << trackType);
+        sp<AMessage> msg = new AMessage(kWhatReadBuffer, id());
+        msg->setInt32("trackType", trackType);
+        msg->post();
+    }
 }
 
 void NuPlayer::GenericSource::onReadBuffer(sp<AMessage> msg) {
     int32_t tmpType;
     CHECK(msg->findInt32("trackType", &tmpType));
     media_track_type trackType = (media_track_type)tmpType;
+    {
+        // only protect the variable change, as readBuffer may
+        // take considerable time.  This may result in one extra
+        // read being processed, but that is benign.
+        Mutex::Autolock _l(mReadBufferLock);
+        mPendingReadBufferTypes &= ~(1 << trackType);
+    }
     readBuffer(trackType);
 }