Bug 1171499 - Defer processing GMP EncodingComplete() calls until intr shmem allocs are finished. r=jesup

dom/media/gmp/GMPContentChild.cpp

@@ -98,13 +98,15 @@ GMPContentChild::DeallocPGMPVideoDecoderChild(PGMPVideoDecoderChild* aActor)
 PGMPVideoEncoderChild*
 GMPContentChild::AllocPGMPVideoEncoderChild()
 {
-  return new GMPVideoEncoderChild(this);
+  GMPVideoEncoderChild* actor = new GMPVideoEncoderChild(this);
+  actor->AddRef();
+  return actor;
 }
 
 bool
 GMPContentChild::DeallocPGMPVideoEncoderChild(PGMPVideoEncoderChild* aActor)
 {
-  delete aActor;
+  static_cast<GMPVideoEncoderChild*>(aActor)->Release();
   return true;
 }
 

dom/media/gmp/GMPVideoEncoderChild.cpp

@@ -9,21 +9,25 @@
 #include "mozilla/unused.h"
 #include "GMPVideoEncodedFrameImpl.h"
 #include "GMPVideoi420FrameImpl.h"
+#include "runnable_utils.h"
 
 namespace mozilla {
 namespace gmp {
 
 GMPVideoEncoderChild::GMPVideoEncoderChild(GMPContentChild* aPlugin)
-: GMPSharedMemManager(aPlugin),
-  mPlugin(aPlugin),
-  mVideoEncoder(nullptr),
-  mVideoHost(this)
+  : GMPSharedMemManager(aPlugin)
+  , mPlugin(aPlugin)
+  , mVideoEncoder(nullptr)
+  , mVideoHost(this)
+  , mNeedShmemIntrCount(0)
+  , mPendingEncodeComplete(false)
 {
   MOZ_ASSERT(mPlugin);
 }
 
 GMPVideoEncoderChild::~GMPVideoEncoderChild()
 {
+  MOZ_ASSERT(!mNeedShmemIntrCount);
 }
 
 void
@@ -162,6 +166,17 @@ GMPVideoEncoderChild::RecvSetPeriodicKeyFrames(const bool& aEnable)
 bool
 GMPVideoEncoderChild::RecvEncodingComplete()
 {
+  MOZ_ASSERT(mPlugin->GMPMessageLoop() == MessageLoop::current());
+
+  if (mNeedShmemIntrCount) {
+    // There's a GMP blocked in Alloc() waiting for the CallNeedShem() to
+    // return a frame they can use. Don't call the GMP's EncodingComplete()
+    // now and don't delete the GMPVideoEncoderChild, defer processing the
+    // EncodingComplete() until once the Alloc() finishes.
+    mPendingEncodeComplete = true;
+    return true;
+  }
+
   if (!mVideoEncoder) {
     unused << Send__delete__(this);
     return false;
@@ -179,5 +194,41 @@ GMPVideoEncoderChild::RecvEncodingComplete()
   return true;
 }
 
+bool
+GMPVideoEncoderChild::Alloc(size_t aSize,
+                            Shmem::SharedMemory::SharedMemoryType aType,
+                            Shmem* aMem)
+{
+  MOZ_ASSERT(mPlugin->GMPMessageLoop() == MessageLoop::current());
+
+  bool rv;
+#ifndef SHMEM_ALLOC_IN_CHILD
+  ++mNeedShmemIntrCount;
+  rv = CallNeedShmem(aSize, aMem);
+  --mNeedShmemIntrCount;
+  if (mPendingEncodeComplete) {
+    auto t = NewRunnableMethod(this, &GMPVideoEncoderChild::RecvEncodingComplete);
+    mPlugin->GMPMessageLoop()->PostTask(FROM_HERE, t);
+  }
+#else
+#ifdef GMP_SAFE_SHMEM
+  rv = AllocShmem(aSize, aType, aMem);
+#else
+  rv = AllocUnsafeShmem(aSize, aType, aMem);
+#endif
+#endif
+  return rv;
+}
+
+void
+GMPVideoEncoderChild::Dealloc(Shmem& aMem)
+{
+#ifndef SHMEM_ALLOC_IN_CHILD
+  SendParentShmemForPool(aMem);
+#else
+  DeallocShmem(aMem);
+#endif
+}
+
 } // namespace gmp
 } // namespace mozilla

dom/media/gmp/GMPVideoEncoderChild.h

@@ -22,8 +22,9 @@ class GMPVideoEncoderChild : public PGMPVideoEncoderChild,
                              public GMPSharedMemManager
 {
 public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(GMPVideoEncoderChild);
+
   explicit GMPVideoEncoderChild(GMPContentChild* aPlugin);
-  virtual ~GMPVideoEncoderChild();
 
   void Init(GMPVideoEncoder* aEncoder);
   GMPVideoHostImpl& Host();
@@ -35,28 +36,13 @@ public:
   virtual void Error(GMPErr aError) override;
 
   // GMPSharedMemManager
-  virtual bool Alloc(size_t aSize, Shmem::SharedMemory::SharedMemoryType aType, Shmem* aMem) override
-  {
-#ifndef SHMEM_ALLOC_IN_CHILD
-    return CallNeedShmem(aSize, aMem);
-#else
-#ifdef GMP_SAFE_SHMEM
-    return AllocShmem(aSize, aType, aMem);
-#else
-    return AllocUnsafeShmem(aSize, aType, aMem);
-#endif
-#endif
-  }
-  virtual void Dealloc(Shmem& aMem) override
-  {
-#ifndef SHMEM_ALLOC_IN_CHILD
-    SendParentShmemForPool(aMem);
-#else
-    DeallocShmem(aMem);
-#endif
-  }
+  virtual bool Alloc(size_t aSize, Shmem::SharedMemory::SharedMemoryType aType,
+    Shmem* aMem) override;
+  virtual void Dealloc(Shmem& aMem) override;
 
 private:
+  virtual ~GMPVideoEncoderChild();
+
   // PGMPVideoEncoderChild
   virtual bool RecvInitEncode(const GMPVideoCodec& aCodecSettings,
                               InfallibleTArray<uint8_t>&& aCodecSpecific,
@@ -76,6 +62,11 @@ private:
   GMPContentChild* mPlugin;
   GMPVideoEncoder* mVideoEncoder;
   GMPVideoHostImpl mVideoHost;
+
+  // Non-zero when a GMP is blocked spinning the IPC message loop while
+  // waiting on an NeedShmem to complete.
+  int mNeedShmemIntrCount;
+  bool mPendingEncodeComplete;
 };
 
 } // namespace gmp