Bug 924678: Stop MP3 parser if decoder got cleared, r=doublec

If the decoder has been cleaned up, there is no point in further
parsing the MP3 file. This patch makes the I/O logic stop in that
case.

The patch also fixes a bug where the beginning of an MP3 chunk was
parsed multiple times if the chunk is larger than 4 GiB.

--HG--
extra : rebase_source : d247ed3995991d362c51a0666274e9de3b90b7d2

content/media/omx/OmxDecoder.cpp

@@ -62,8 +62,8 @@ private:
 };
 
 // When loading an MP3 stream from a file, we need to parse the file's
-// content to find its duration. Reading files of 100 Mib or more can
-// delay the player app noticably, so the file os read and decoded in
+// content to find its duration. Reading files of 100 MiB or more can
+// delay the player app noticably, so the file is read and decoded in
 // smaller chunks.
 //
 // We first read on the decode thread, but parsing must be done on the
@@ -79,7 +79,9 @@ private:
 class OmxDecoderNotifyDataArrivedRunnable : public nsRunnable
 {
 public:
-  OmxDecoderNotifyDataArrivedRunnable(android::OmxDecoder* aOmxDecoder, const char* aBuffer, uint64_t aLength, int64_t aOffset, uint64_t aFullLength)
+  OmxDecoderNotifyDataArrivedRunnable(android::OmxDecoder* aOmxDecoder,
+                                      const char* aBuffer, uint64_t aLength,
+                                      int64_t aOffset, uint64_t aFullLength)
   : mOmxDecoder(aOmxDecoder),
     mBuffer(aBuffer),
     mLength(aLength),
@@ -96,24 +98,7 @@ public:
   {
     NS_ASSERTION(NS_IsMainThread(), "Should be on main thread.");
 
-    const char* buffer = mBuffer.get();
-
-    while (mLength) {
-      uint32_t length = std::min<uint64_t>(mLength, UINT32_MAX);
-      mOmxDecoder->NotifyDataArrived(mBuffer.get(), mLength, mOffset);
-
-      buffer  += length;
-      mLength -= length;
-      mOffset += length;
-    }
-
-    if (mOffset < mFullLength) {
-      // We cannot read data in the main thread because it
-      // might block for too long. Instead we post an IO task
-      // to the IO thread if there is more data available.
-      XRE_GetIOMessageLoop()->PostTask(FROM_HERE, new OmxDecoderProcessCachedDataTask(mOmxDecoder.get(), mOffset));
-    }
-
+    NotifyDataArrived();
     Completed();
 
     return NS_OK;
@@ -130,6 +115,32 @@ public:
   }
 
 private:
+  void NotifyDataArrived()
+  {
+    const char* buffer = mBuffer.get();
+
+    while (mLength) {
+      uint32_t length = std::min<uint64_t>(mLength, UINT32_MAX);
+      bool success = mOmxDecoder->NotifyDataArrived(buffer, mLength,
+                                                    mOffset);
+      if (!success) {
+        return;
+      }
+
+      buffer  += length;
+      mLength -= length;
+      mOffset += length;
+    }
+
+    if (mOffset < mFullLength) {
+      // We cannot read data in the main thread because it
+      // might block for too long. Instead we post an IO task
+      // to the IO thread if there is more data available.
+      XRE_GetIOMessageLoop()->PostTask(FROM_HERE,
+          new OmxDecoderProcessCachedDataTask(mOmxDecoder.get(), mOffset));
+    }
+  }
+
   // Call this function at the end of Run() to notify waiting
   // threads.
   void Completed()
@@ -633,10 +644,10 @@ void OmxDecoder::ReleaseDecoder()
   mDecoder = nullptr;
 }
 
-void OmxDecoder::NotifyDataArrived(const char* aBuffer, uint32_t aLength, int64_t aOffset)
+bool OmxDecoder::NotifyDataArrived(const char* aBuffer, uint32_t aLength, int64_t aOffset)
 {
   if (!mAudioTrack.get() || !mIsMp3 || !mMP3FrameParser.IsMP3() || !mDecoder) {
-    return;
+    return false;
   }
 
   mMP3FrameParser.Parse(aBuffer, aLength, aOffset);
@@ -650,6 +661,8 @@ void OmxDecoder::NotifyDataArrived(const char* aBuffer, uint32_t aLength, int64_
     ReentrantMonitorAutoEnter mon(mDecoder->GetReentrantMonitor());
     mDecoder->UpdateEstimatedMediaDuration(mDurationUs);
   }
+
+  return true;
 }
 
 void OmxDecoder::ReleaseVideoBuffer() {

content/media/omx/OmxDecoder.h

@@ -183,7 +183,7 @@ public:
 
   void ReleaseDecoder();
 
-  void NotifyDataArrived(const char* aBuffer, uint32_t aLength, int64_t aOffset);
+  bool NotifyDataArrived(const char* aBuffer, uint32_t aLength, int64_t aOffset);
 
   void GetDuration(int64_t *durationUs) {
     *durationUs = mDurationUs;