Bug 1389021 - Force CompositorManagerParent to close before shutting down the compositor thread. r=dvander

gfx/layers/ipc/CompositorManagerParent.cpp

@@ -9,12 +9,14 @@
 #include "mozilla/layers/CompositorBridgeParent.h"
 #include "mozilla/layers/CrossProcessCompositorBridgeParent.h"
 #include "mozilla/layers/CompositorThread.h"
+#include "nsAutoPtr.h"
 #include "VsyncSource.h"
 
 namespace mozilla {
 namespace layers {
 
 StaticRefPtr<CompositorManagerParent> CompositorManagerParent::sInstance;
+StaticAutoPtr<nsTArray<CompositorManagerParent*>> CompositorManagerParent::sActiveActors;
 StaticMutex CompositorManagerParent::sMutex;
 
 /* static */ already_AddRefed<CompositorManagerParent>
@@ -44,6 +46,11 @@ CompositorManagerParent::CreateSameProcess()
   // we don't use that in the same process case.
   parent.get()->AddRef();
   sInstance = parent;
+
+  if (!sActiveActors) {
+    sActiveActors = new nsTArray<CompositorManagerParent*>();
+  }
+  sActiveActors->AppendElement(parent);
   return parent.forget();
 }
 
@@ -127,6 +134,12 @@ CompositorManagerParent::Bind(Endpoint<PCompositorManagerParent>&& aEndpoint)
   // Add the IPDL reference to ourself, so we can't get freed until IPDL is
   // done with us.
   AddRef();
+
+  StaticMutexAutoLock lock(sMutex);
+  if (!sActiveActors) {
+    sActiveActors = new nsTArray<CompositorManagerParent*>();
+  }
+  sActiveActors->AppendElement(this);
 }
 
 void
@@ -146,6 +159,10 @@ CompositorManagerParent::DeallocPCompositorManagerParent()
                             this,
                             &CompositorManagerParent::DeferredDestroy));
 
+  StaticMutexAutoLock lock(sMutex);
+  if (sActiveActors) {
+    sActiveActors->RemoveElement(this);
+  }
   Release();
 }
 
@@ -155,6 +172,36 @@ CompositorManagerParent::DeferredDestroy()
   mCompositorThreadHolder = nullptr;
 }
 
+/* static */ void
+CompositorManagerParent::ShutdownInternal()
+{
+  nsAutoPtr<nsTArray<CompositorManagerParent*>> actors;
+
+  // We move here because we may attempt to acquire the same lock during the
+  // destroy to remove the reference in sActiveActors.
+  {
+    StaticMutexAutoLock lock(sMutex);
+    actors = sActiveActors.forget();
+  }
+
+  if (actors) {
+    for (auto& actor : *actors) {
+      actor->Close();
+    }
+  }
+}
+
+/* static */ void
+CompositorManagerParent::Shutdown()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  CompositorThreadHolder::Loop()->PostTask(
+      NS_NewRunnableFunction("layers::CompositorManagerParent::Shutdown", []() -> void {
+        CompositorManagerParent::ShutdownInternal();
+      }));
+}
+
 PCompositorBridgeParent*
 CompositorManagerParent::AllocPCompositorBridgeParent(const CompositorBridgeOptions& aOpt)
 {

gfx/layers/ipc/CompositorManagerParent.h

@@ -27,6 +27,7 @@ class CompositorManagerParent final : public PCompositorManagerParent
 public:
   static already_AddRefed<CompositorManagerParent> CreateSameProcess();
   static void Create(Endpoint<PCompositorManagerParent>&& aEndpoint);
+  static void Shutdown();
 
   static already_AddRefed<CompositorBridgeParent>
   CreateSameProcessWidgetCompositorBridge(CSSToLayoutDeviceScale aScale,
@@ -41,8 +42,11 @@ public:
 
 private:
   static StaticRefPtr<CompositorManagerParent> sInstance;
+  static StaticAutoPtr<nsTArray<CompositorManagerParent*>> sActiveActors;
   static StaticMutex sMutex;
 
+  static void ShutdownInternal();
+
   CompositorManagerParent();
   ~CompositorManagerParent() override;
 

gfx/layers/ipc/CompositorThread.cpp

@@ -159,6 +159,7 @@ CompositorThreadHolder::Shutdown()
   ReleaseImageBridgeParentSingleton();
   gfx::ReleaseVRManagerParentSingleton();
   MediaSystemResourceService::Shutdown();
+  CompositorManagerParent::Shutdown();
 
   sCompositorThreadHolder = nullptr;