Bug 1514874 - start RDD process on-demand r=jya,jld

Differential Revision: https://phabricator.services.mozilla.com/D15775

--HG--
extra : moz-landing-system : lando

dom/ipc/ContentChild.cpp

@@ -73,6 +73,7 @@
 #include "mozilla/layers/CompositorManagerChild.h"
 #include "mozilla/layers/ContentProcessController.h"
 #include "mozilla/layers/ImageBridgeChild.h"
+#include "mozilla/layers/SynchronousTask.h"  // for LaunchRDDProcess
 #include "mozilla/loader/ScriptCacheActors.h"
 #include "mozilla/net/NeckoChild.h"
 #include "mozilla/net/CookieServiceChild.h"
@@ -1116,6 +1117,22 @@ void ContentChild::GetProcessName(nsAString& aName) const {
   aName.Assign(mProcessName);
 }
 
+void ContentChild::LaunchRDDProcess() {
+  SynchronousTask task("LaunchRDDProcess");
+  SystemGroup::Dispatch(
+      TaskCategory::Other,
+      NS_NewRunnableFunction("LaunchRDDProcess", [&task, this] {
+        AutoCompleteTask complete(&task);
+        nsresult rv;
+        Endpoint<PRemoteDecoderManagerChild> endpoint;
+        Unused << SendLaunchRDDProcess(&rv, &endpoint);
+        if (rv == NS_OK) {
+          RemoteDecoderManagerChild::InitForContent(std::move(endpoint));
+        }
+      }));
+  task.Wait();
+}
+
 bool ContentChild::IsAlive() const { return mIsAlive; }
 
 bool ContentChild::IsShuttingDown() const { return mShuttingDown; }
@@ -1440,12 +1457,6 @@ mozilla::ipc::IPCResult ContentChild::RecvReinitRenderingForDeviceReset() {
   return IPC_OK();
 }
 
-mozilla::ipc::IPCResult ContentChild::RecvInitRemoteDecoder(
-    Endpoint<PRemoteDecoderManagerChild>&& aRemoteManager) {
-  RemoteDecoderManagerChild::InitForContent(std::move(aRemoteManager));
-  return IPC_OK();
-}
-
 #if defined(XP_MACOSX) && defined(MOZ_CONTENT_SANDBOX)
 extern "C" {
 CGError CGSSetDenyWindowServerConnections(bool);

dom/ipc/ContentChild.h

@@ -133,6 +133,8 @@ class ContentChild final : public PContentChild,
 
   void GetProcessName(nsACString& aName) const;
 
+  void LaunchRDDProcess();
+
 #if defined(XP_MACOSX) && defined(MOZ_CONTENT_SANDBOX)
   void GetProfileDir(nsIFile** aProfileDir) const {
     *aProfileDir = mProfileDir;
@@ -188,9 +190,6 @@ class ContentChild final : public PContentChild,
 
   mozilla::ipc::IPCResult RecvReinitRenderingForDeviceReset() override;
 
-  virtual mozilla::ipc::IPCResult RecvInitRemoteDecoder(
-      Endpoint<PRemoteDecoderManagerChild>&& aRemoteManager) override;
-
   virtual mozilla::ipc::IPCResult RecvSetProcessSandbox(
       const MaybeFileDesc& aBroker) override;
 

dom/ipc/ContentParent.cpp

@@ -1119,6 +1119,31 @@ mozilla::ipc::IPCResult ContentParent::RecvConnectPluginBridge(
   return IPC_OK();
 }
 
+mozilla::ipc::IPCResult ContentParent::RecvLaunchRDDProcess(
+    nsresult* aRv, Endpoint<PRemoteDecoderManagerChild>* aEndpoint) {
+  *aRv = NS_OK;
+
+  if (XRE_IsParentProcess() &&
+      BrowserTabsRemoteAutostart() &&  // only do rdd process if e10s on
+      Preferences::GetBool("media.rdd-process.enabled", false)) {
+    RDDProcessManager* rdd = RDDProcessManager::Get();
+    if (rdd) {
+      rdd->LaunchRDDProcess();
+
+      bool rddOpened = rdd->CreateContentBridge(OtherPid(), aEndpoint);
+      MOZ_ASSERT(rddOpened);
+
+      if (!rddOpened) {
+        *aRv = NS_ERROR_NOT_AVAILABLE;
+      }
+    } else {
+      *aRv = NS_ERROR_NOT_AVAILABLE;
+    }
+  }
+
+  return IPC_OK();
+}
+
 /*static*/ TabParent* ContentParent::CreateBrowser(
     const TabContext& aContext, Element* aFrameElement,
     ContentParent* aOpenerContentParent, TabParent* aSameTabGroupAs,
@@ -2612,22 +2637,6 @@ void ContentParent::InitInternal(ProcessPriority aInitialPriority) {
 
   gpm->AddListener(this);
 
-  if (StaticPrefs::MediaRddProcessEnabled() && BrowserTabsRemoteAutostart()) {
-    RDDProcessManager* rdd = RDDProcessManager::Get();
-
-    Endpoint<PRemoteDecoderManagerChild> remoteManager;
-    bool rddOpened = rdd->CreateContentBridge(OtherPid(), &remoteManager);
-    MOZ_ASSERT(rddOpened);
-
-    if (rddOpened) {
-      // not using std::move here (like in SendInitRendering above) because
-      // clang-tidy says:
-      // Warning: Passing result of std::move() as a const reference
-      // argument; no move will actually happen
-      Unused << SendInitRemoteDecoder(remoteManager);
-    }
-  }
-
   nsStyleSheetService* sheetService = nsStyleSheetService::GetInstance();
   if (sheetService) {
     // This looks like a lot of work, but in a normal browser session we just

dom/ipc/ContentParent.h

@@ -302,6 +302,9 @@ class ContentParent final : public PContentParent,
       const uint32_t& aPluginId, nsresult* aRv,
       Endpoint<PPluginModuleParent>* aEndpoint) override;
 
+  virtual mozilla::ipc::IPCResult RecvLaunchRDDProcess(
+      nsresult* aRv, Endpoint<PRemoteDecoderManagerChild>* aEndpoint) override;
+
   virtual mozilla::ipc::IPCResult RecvUngrabPointer(
       const uint32_t& aTime) override;
 

dom/ipc/PContent.ipdl

@@ -435,8 +435,6 @@ child:
     // Re-create the rendering stack for a device reset.
     async ReinitRenderingForDeviceReset();
 
-    async InitRemoteDecoder(Endpoint<PRemoteDecoderManagerChild> decoder);
-
     /**
      * Enable system-level sandboxing features, if available.  Can
      * usually only be performed zero or one times.  The child may
@@ -805,6 +803,10 @@ parent:
     sync ConnectPluginBridge(uint32_t aPluginId)
         returns (nsresult rv, Endpoint<PPluginModuleParent> aEndpoint);
 
+    // See Bug 1518344 - Investigate using async for PContent::LaunchRDDProcess
+    sync LaunchRDDProcess()
+        returns (nsresult rv, Endpoint<PRemoteDecoderManagerChild> aEndpoint);
+
     async PJavaScript();
 
     async PRemoteSpellcheckEngine();

dom/media/ipc/RemoteDecoderModule.cpp

@@ -6,6 +6,7 @@
 #include "RemoteDecoderModule.h"
 
 #include "base/thread.h"
+#include "mozilla/dom/ContentChild.h"  // for launching RDD w/ ContentChild
 #include "mozilla/layers/SynchronousTask.h"
 #include "mozilla/StaticPrefs.h"
 
@@ -19,16 +20,10 @@
 namespace mozilla {
 
 using base::Thread;
+using dom::ContentChild;
 using namespace ipc;
 using namespace layers;
 
-nsresult RemoteDecoderModule::Startup() {
-  if (!RemoteDecoderManagerChild::GetManagerThread()) {
-    return NS_ERROR_FAILURE;
-  }
-  return NS_OK;
-}
-
 bool RemoteDecoderModule::SupportsMimeType(
     const nsACString& aMimeType, DecoderDoctorDiagnostics* aDiagnostics) const {
   bool supports = false;
@@ -46,6 +41,11 @@ bool RemoteDecoderModule::SupportsMimeType(
 
 already_AddRefed<MediaDataDecoder> RemoteDecoderModule::CreateVideoDecoder(
     const CreateDecoderParams& aParams) {
+  if (XRE_IsContentProcess()) {
+    ContentChild* contentChild = ContentChild::GetSingleton();
+    contentChild->LaunchRDDProcess();
+  }
+
   RemoteVideoDecoderChild* child = new RemoteVideoDecoderChild();
   RefPtr<RemoteMediaDataDecoder> object = new RemoteMediaDataDecoder(
       child, RemoteDecoderManagerChild::GetManagerThread(),

dom/media/ipc/RemoteDecoderModule.h

@@ -17,8 +17,6 @@ class RemoteDecoderModule : public PlatformDecoderModule {
  public:
   RemoteDecoderModule() = default;
 
-  nsresult Startup() override;
-
   bool SupportsMimeType(const nsACString& aMimeType,
                         DecoderDoctorDiagnostics* aDiagnostics) const override;
 

gfx/thebes/gfxPlatform.cpp

@@ -931,15 +931,6 @@ void gfxPlatform::Init() {
     gpu->LaunchGPUProcess();
   }
 
-  if (XRE_IsParentProcess() &&
-      BrowserTabsRemoteAutostart() &&  // only do rdd process if e10s on
-      Preferences::GetBool("media.rdd-process.enabled", false)) {
-    RDDProcessManager* rdd = RDDProcessManager::Get();
-    if (rdd) {
-      rdd->LaunchRDDProcess();
-    }
-  }
-
   gLastUsedFrameRate = ForceSoftwareVsync() ? GetSoftwareVsyncRate() : -1;
   auto updateFrameRateCallback = [](const GfxPrefValue& aValue) -> void {
     int32_t newRate = ForceSoftwareVsync() ? GetSoftwareVsyncRate() : -1;

ipc/ipdl/sync-messages.ini

@@ -914,6 +914,8 @@ description =
 description =
 [PRemoteDecoderManager::PRemoteVideoDecoder]
 description = See Bug 1505976 - investigate changing to async instead of matching GPU pattern
+[PContent::LaunchRDDProcess]
+description = See Bug 1518344 - investigate using async for PContent::LaunchRDDProcess
 [PVideoDecoderManager::PVideoDecoder]
 description =
 [PVideoDecoderManager::Readback]