From c931bd1038fee9c67ca84037fa664390ce46bcad Mon Sep 17 00:00:00 2001
From: John Lin <jolin@mozilla.com>
Date: Mon, 9 Nov 2015 18:58:00 +0100
Subject: [PATCH] Bug 1216895 - assert that decoder methods are run on correct
 thread. r=jya

---
 .../platforms/gonk/GonkMediaDataDecoder.cpp   | 35 +++++++++++++++++++
 .../platforms/gonk/GonkMediaDataDecoder.h     | 18 ++++++++--
 2 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/dom/media/platforms/gonk/GonkMediaDataDecoder.cpp b/dom/media/platforms/gonk/GonkMediaDataDecoder.cpp
index 858c423d79c..1d91516f10b 100644
--- a/dom/media/platforms/gonk/GonkMediaDataDecoder.cpp
+++ b/dom/media/platforms/gonk/GonkMediaDataDecoder.cpp
@@ -16,6 +16,10 @@
 #define INPUT_TIMEOUT_US 0LL // Don't wait for buffer if none is available.
 #define MIN_QUEUED_SAMPLES 2
 
+#ifdef DEBUG
+#include <utils/AndroidThreads.h>
+#endif
+
 extern PRLogModuleInfo* GetPDMLog();
 #define LOG(...) MOZ_LOG(GetPDMLog(), mozilla::LogLevel::Debug, (__VA_ARGS__))
 
@@ -41,6 +45,11 @@ GonkDecoderManager::InitLoopers(MediaData::Type aType)
   mTaskLooper->setName(name.c_str());
   mTaskLooper->registerHandler(this);
 
+#ifdef DEBUG
+  sp<AMessage> findThreadId(new AMessage(kNotifyFindLooperId, id()));
+  findThreadId->post();
+#endif
+
   return mDecodeLooper->start() == OK && mTaskLooper->start() == OK;
 }
 
@@ -71,6 +80,8 @@ GonkDecoderManager::Input(MediaRawData* aSample)
 int32_t
 GonkDecoderManager::ProcessQueuedSamples()
 {
+  MOZ_ASSERT(OnTaskLooper());
+
   MutexAutoLock lock(mMutex);
   status_t rv;
   while (mQueuedSamples.Length()) {
@@ -146,6 +157,8 @@ GonkDecoderManager::NumQueuedSamples()
 void
 GonkDecoderManager::ProcessInput(bool aEndOfStream)
 {
+  MOZ_ASSERT(OnTaskLooper());
+
   status_t rv = ProcessQueuedSamples();
   if (rv >= 0) {
     if (!aEndOfStream && rv <= MIN_QUEUED_SAMPLES) {
@@ -170,6 +183,8 @@ GonkDecoderManager::ProcessInput(bool aEndOfStream)
 void
 GonkDecoderManager::ProcessFlush()
 {
+  MOZ_ASSERT(OnTaskLooper());
+
   mLastTime = INT64_MIN;
   MonitorAutoLock lock(mFlushMonitor);
   mWaitOutput.Clear();
@@ -188,6 +203,8 @@ GonkDecoderManager::ProcessFlush()
 void
 GonkDecoderManager::UpdateWaitingList(int64_t aForgetUpTo)
 {
+  MOZ_ASSERT(OnTaskLooper());
+
   size_t i;
   for (i = 0; i < mWaitOutput.Length(); i++) {
     const auto& item = mWaitOutput.ElementAt(i);
@@ -203,6 +220,8 @@ GonkDecoderManager::UpdateWaitingList(int64_t aForgetUpTo)
 void
 GonkDecoderManager::ProcessToDo(bool aEndOfStream)
 {
+  MOZ_ASSERT(OnTaskLooper());
+
   MOZ_ASSERT(mToDo.get() != nullptr);
   mToDo.clear();
 
@@ -274,6 +293,14 @@ GonkDecoderManager::onMessageReceived(const sp<AMessage> &aMessage)
       ProcessToDo(aMessage->findInt32("input-eos", &eos) && eos);
       break;
     }
+#ifdef DEBUG
+    case kNotifyFindLooperId:
+    {
+      mTaskLooperId = androidGetThreadId();
+      MOZ_ASSERT(mTaskLooperId);
+      break;
+    }
+#endif
     default:
       {
         TRESPASS();
@@ -282,6 +309,14 @@ GonkDecoderManager::onMessageReceived(const sp<AMessage> &aMessage)
   }
 }
 
+#ifdef DEBUG
+bool
+GonkDecoderManager::OnTaskLooper()
+{
+  return androidGetThreadId() == mTaskLooperId;
+}
+#endif
+
 GonkMediaDataDecoder::GonkMediaDataDecoder(GonkDecoderManager* aManager,
                                            FlushableTaskQueue* aTaskQueue,
                                            MediaDataDecoderCallback* aCallback)
diff --git a/dom/media/platforms/gonk/GonkMediaDataDecoder.h b/dom/media/platforms/gonk/GonkMediaDataDecoder.h
index e5a0e59f6e6..334679e942d 100644
--- a/dom/media/platforms/gonk/GonkMediaDataDecoder.h
+++ b/dom/media/platforms/gonk/GonkMediaDataDecoder.h
@@ -70,7 +70,7 @@ protected:
                           RefPtr<MediaData>& aOutput) = 0;
 
   // Send queued samples to OMX. It returns how many samples are still in
-  // queue after processing, or negtive error code if failed.
+  // queue after processing, or negative error code if failed.
   int32_t ProcessQueuedSamples();
 
   void ProcessInput(bool aEndOfStream);
@@ -88,6 +88,7 @@ protected:
   // Looper to run decode tasks such as processing input, output, flush, and
   // recycling output buffers.
   android::sp<android::ALooper> mTaskLooper;
+  // Message codes for tasks running on mTaskLooper.
   enum {
     // Decoder will send this to indicate internal state change such as input or
     // output buffers availability. Used to run pending input & output tasks.
@@ -96,6 +97,9 @@ protected:
     kNotifyProcessFlush = 'npf ',
     // Used to process queued samples when there is new input.
     kNotifyProcessInput = 'npi ',
+#ifdef DEBUG
+    kNotifyFindLooperId = 'nfli',
+#endif
   };
 
   MozPromiseHolder<InitPromise> mInitPromise;
@@ -106,10 +110,11 @@ protected:
   // Samples are queued in caller's thread and dequeued in mTaskLooper.
   nsTArray<RefPtr<MediaRawData>> mQueuedSamples;
 
-  int64_t mLastTime;  // The last decoded frame presentation time.
+  // The last decoded frame presentation time. Only accessed on mTaskLooper.
+  int64_t mLastTime;
 
   Monitor mFlushMonitor; // Waits for flushing to complete.
-  bool mIsFlushing;
+  bool mIsFlushing; // Protected by mFlushMonitor.
 
   // Remembers the notification that is currently waiting for the decoder event
   // to avoid requesting more than one notification at the time, which is
@@ -134,6 +139,13 @@ protected:
 
 private:
   void UpdateWaitingList(int64_t aForgetUpTo);
+
+#ifdef DEBUG
+  typedef void* LooperId;
+
+  bool OnTaskLooper();
+  LooperId mTaskLooperId;
+#endif
 };
 
 class AutoReleaseMediaBuffer