1 files changed, 195 insertions, 0 deletions
diff --git a/gfx/layers/ipc/CompositorThread.cpp b/gfx/layers/ipc/CompositorThread.cpp
new file mode 100644
index 0000000000..65fbdc66f1
--- /dev/null
+++ b/gfx/layers/ipc/CompositorThread.cpp
@@ -0,0 +1,195 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#include "CompositorThread.h"
+
+#include "CompositorBridgeParent.h"
+#include "gfxGradientCache.h"
+#include "MainThreadUtils.h"
+#include "VRManagerParent.h"
+#include "mozilla/BackgroundHangMonitor.h"
+#include "mozilla/SpinEventLoopUntil.h"
+#include "mozilla/gfx/gfxVars.h"
+#include "mozilla/layers/CompositorManagerParent.h"
+#include "mozilla/layers/ImageBridgeParent.h"
+#include "mozilla/layers/VideoBridgeParent.h"
+#include "mozilla/media/MediaSystemResourceService.h"
+#include "nsThread.h"
+#include "nsThreadUtils.h"
+
+namespace mozilla {
+namespace layers {
+
+static StaticRefPtr<CompositorThreadHolder> sCompositorThreadHolder;
+static Atomic<bool> sFinishedCompositorShutDown(false);
+static mozilla::BackgroundHangMonitor* sBackgroundHangMonitor;
+static ProfilerThreadId sProfilerThreadId;
+
+nsIThread* CompositorThread() {
+  return sCompositorThreadHolder
+             ? sCompositorThreadHolder->GetCompositorThread()
+             : nullptr;
+}
+
+CompositorThreadHolder* CompositorThreadHolder::GetSingleton() {
+  return sCompositorThreadHolder;
+}
+
+CompositorThreadHolder::CompositorThreadHolder()
+    : mCompositorThread(CreateCompositorThread()) {
+  MOZ_ASSERT(NS_IsMainThread());
+}
+
+CompositorThreadHolder::~CompositorThreadHolder() {
+  sFinishedCompositorShutDown = true;
+}
+
+/* static */ already_AddRefed<nsIThread>
+CompositorThreadHolder::CreateCompositorThread() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  MOZ_ASSERT(!sCompositorThreadHolder,
+             "The compositor thread has already been started!");
+
+  // When the CanvasRenderer thread is disabled, WebGL may be handled on this
+  // thread, requiring a bigger stack size. See: CanvasManagerParent::Init
+  //
+  // This is 4M, which is higher than the default 256K.
+  // Increased with bug 1753349 to accommodate the `chromium/5359` branch of
+  // ANGLE, which has large peak stack usage for some pathological shader
+  // compilations.
+  //
+  // Previously increased to 512K to accommodate Mesa in bug 1753340.
+  //
+  // Previously increased to 320K to avoid a stack overflow in the
+  // Intel Vulkan driver initialization in bug 1716120.
+  //
+  // Note: we only override it if it's limited already.
+  uint32_t stackSize = nsIThreadManager::DEFAULT_STACK_SIZE;
+  if (stackSize) {
+    stackSize =
+        std::max(stackSize, gfx::gfxVars::SupportsThreadsafeGL() &&
+                                    !gfx::gfxVars::UseCanvasRenderThread()
+                                ? 4096U << 10
+                                : 512U << 10);
+  }
+
+  nsCOMPtr<nsIThread> compositorThread;
+  nsresult rv = NS_NewNamedThread(
+      "Compositor", getter_AddRefs(compositorThread),
+      NS_NewRunnableFunction(
+          "CompositorThreadHolder::CompositorThreadHolderSetup",
+          []() {
+            sProfilerThreadId = profiler_current_thread_id();
+            sBackgroundHangMonitor = new mozilla::BackgroundHangMonitor(
+                "Compositor",
+                /* Timeout values are powers-of-two to enable us get better
+                   data. 128ms is chosen for transient hangs because 8Hz should
+                   be the minimally acceptable goal for Compositor
+                   responsiveness (normal goal is 60Hz). */
+                128,
+                /* 2048ms is chosen for permanent hangs because it's longer than
+                 * most Compositor hangs seen in the wild, but is short enough
+                 * to not miss getting native hang stacks. */
+                2048);
+            nsCOMPtr<nsIThread> thread = NS_GetCurrentThread();
+            static_cast<nsThread*>(thread.get())->SetUseHangMonitor(true);
+          }),
+      {.stackSize = stackSize});
+
+  if (NS_FAILED(rv)) {
+    return nullptr;
+  }
+
+  CompositorBridgeParent::Setup();
+  ImageBridgeParent::Setup();
+
+  return compositorThread.forget();
+}
+
+void CompositorThreadHolder::Start() {
+  MOZ_ASSERT(NS_IsMainThread(), "Should be on the main Thread!");
+  MOZ_ASSERT(!sCompositorThreadHolder,
+             "The compositor thread has already been started!");
+
+  // We unset the holder instead of asserting because failing to start the
+  // compositor thread may not be a fatal error. As long as this succeeds in
+  // either the GPU process or the UI process, the user will have a usable
+  // browser. If we get neither, it will crash as soon as we try to post to the
+  // compositor thread for the first time.
+  sProfilerThreadId = ProfilerThreadId();
+  sCompositorThreadHolder = new CompositorThreadHolder();
+  if (!sCompositorThreadHolder->GetCompositorThread()) {
+    gfxCriticalNote << "Compositor thread not started ("
+                    << XRE_IsParentProcess() << ")";
+    sCompositorThreadHolder = nullptr;
+  }
+}
+
+void CompositorThreadHolder::Shutdown() {
+  MOZ_ASSERT(NS_IsMainThread(), "Should be on the main Thread!");
+  if (!sCompositorThreadHolder) {
+    // We've already shutdown or never started.
+    return;
+  }
+
+  ImageBridgeParent::Shutdown();
+  gfx::VRManagerParent::Shutdown();
+  MediaSystemResourceService::Shutdown();
+  CompositorManagerParent::Shutdown();
+  gfx::gfxGradientCache::Shutdown();
+
+  // Ensure there are no pending tasks that would cause an access to the
+  // thread's HangMonitor. APZ and Canvas can keep a reference to the compositor
+  // thread and may continue to dispatch tasks on it as the system shuts down.
+  CompositorThread()->Dispatch(NS_NewRunnableFunction(
+      "CompositorThreadHolder::Shutdown",
+      [compositorThreadHolder =
+           RefPtr<CompositorThreadHolder>(sCompositorThreadHolder),
+       backgroundHangMonitor = UniquePtr<mozilla::BackgroundHangMonitor>(
+           sBackgroundHangMonitor)]() {
+        VideoBridgeParent::UnregisterExternalImages();
+        nsCOMPtr<nsIThread> thread = NS_GetCurrentThread();
+        static_cast<nsThread*>(thread.get())->SetUseHangMonitor(false);
+      }));
+
+  sCompositorThreadHolder = nullptr;
+  sBackgroundHangMonitor = nullptr;
+
+  SpinEventLoopUntil("CompositorThreadHolder::Shutdown"_ns, [&]() {
+    bool finished = sFinishedCompositorShutDown;
+    return finished;
+  });
+
+  // At this point, the CompositorThreadHolder instance will have been
+  // destroyed, but the compositor thread itself may still be running due to
+  // APZ/Canvas code holding a reference to the underlying
+  // nsIThread/nsISerialEventTarget. Any tasks scheduled to run on the
+  // compositor thread earlier in this function will have been run to
+  // completion.
+  CompositorBridgeParent::FinishShutdown();
+}
+
+/* static */
+bool CompositorThreadHolder::IsInCompositorThread() {
+  if (!CompositorThread()) {
+    return false;
+  }
+  bool in = false;
+  MOZ_ALWAYS_SUCCEEDS(CompositorThread()->IsOnCurrentThread(&in));
+  return in;
+}
+
+/* static */
+ProfilerThreadId CompositorThreadHolder::GetThreadId() {
+  return sCompositorThreadHolder ? sProfilerThreadId : ProfilerThreadId();
+}
+
+}  // namespace layers
+}  // namespace mozilla
+
+bool NS_IsInCompositorThread() {
+  return mozilla::layers::CompositorThreadHolder::IsInCompositorThread();
+}