1 files changed, 168 insertions, 0 deletions
diff --git a/tools/profiler/gecko/ChildProfilerController.cpp b/tools/profiler/gecko/ChildProfilerController.cpp
new file mode 100644
index 0000000000..1ed7c238a4
--- /dev/null
+++ b/tools/profiler/gecko/ChildProfilerController.cpp
@@ -0,0 +1,168 @@
+/* -*- 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 "ChildProfilerController.h"
+
+#include "ProfilerChild.h"
+
+#include "mozilla/ProfilerState.h"
+#include "mozilla/ipc/Endpoint.h"
+#include "nsExceptionHandler.h"
+#include "nsIThread.h"
+#include "nsThreadUtils.h"
+
+using namespace mozilla::ipc;
+
+namespace mozilla {
+
+/* static */
+already_AddRefed<ChildProfilerController> ChildProfilerController::Create(
+    mozilla::ipc::Endpoint<PProfilerChild>&& aEndpoint) {
+  MOZ_RELEASE_ASSERT(NS_IsMainThread());
+  RefPtr<ChildProfilerController> cpc = new ChildProfilerController();
+  cpc->Init(std::move(aEndpoint));
+  return cpc.forget();
+}
+
+ChildProfilerController::ChildProfilerController()
+    : mThread(nullptr, "ChildProfilerController::mThread") {
+  MOZ_COUNT_CTOR(ChildProfilerController);
+}
+
+void ChildProfilerController::Init(Endpoint<PProfilerChild>&& aEndpoint) {
+  RefPtr<nsIThread> newProfilerChildThread;
+  if (NS_SUCCEEDED(NS_NewNamedThread("ProfilerChild",
+                                     getter_AddRefs(newProfilerChildThread)))) {
+    {
+      auto lock = mThread.Lock();
+      RefPtr<nsIThread>& lockedmThread = lock.ref();
+      MOZ_ASSERT(!lockedmThread, "There is already a ProfilerChild thread");
+      // Copy ref'd ptr into mThread. Don't move/swap, so that
+      // newProfilerChildThread can be used below.
+      lockedmThread = newProfilerChildThread;
+    }
+    // Now that mThread has been set, run SetupProfilerChild on the thread.
+    newProfilerChildThread->Dispatch(
+        NewRunnableMethod<Endpoint<PProfilerChild>&&>(
+            "ChildProfilerController::SetupProfilerChild", this,
+            &ChildProfilerController::SetupProfilerChild, std::move(aEndpoint)),
+        NS_DISPATCH_NORMAL);
+  }
+}
+
+nsCString ChildProfilerController::GrabShutdownProfileAndShutdown() {
+  nsCString shutdownProfile;
+  ShutdownAndMaybeGrabShutdownProfileFirst(&shutdownProfile);
+  return shutdownProfile;
+}
+
+void ChildProfilerController::Shutdown() {
+  ShutdownAndMaybeGrabShutdownProfileFirst(nullptr);
+}
+
+void ChildProfilerController::ShutdownAndMaybeGrabShutdownProfileFirst(
+    nsCString* aOutShutdownProfile) {
+  // First, get the owning reference out of mThread, so it cannot be used in
+  // ChildProfilerController after this (including re-entrantly during the
+  // profilerChildThread->Shutdown() inner event loop below).
+  RefPtr<nsIThread> profilerChildThread;
+  {
+    auto lock = mThread.Lock();
+    RefPtr<nsIThread>& lockedmThread = lock.ref();
+    lockedmThread.swap(profilerChildThread);
+  }
+  if (profilerChildThread) {
+    if (profiler_is_active()) {
+      CrashReporter::AnnotateCrashReport(
+          CrashReporter::Annotation::ProfilerChildShutdownPhase,
+          "Profiling - Dispatching ShutdownProfilerChild"_ns);
+      profilerChildThread->Dispatch(
+          NewRunnableMethod<nsCString*>(
+              "ChildProfilerController::ShutdownProfilerChild", this,
+              &ChildProfilerController::ShutdownProfilerChild,
+              aOutShutdownProfile),
+          NS_DISPATCH_NORMAL);
+      // Shut down the thread. This call will spin until all runnables
+      // (including the ShutdownProfilerChild runnable) have been processed.
+      profilerChildThread->Shutdown();
+    } else {
+      CrashReporter::AnnotateCrashReport(
+          CrashReporter::Annotation::ProfilerChildShutdownPhase,
+          "Not profiling - Running ShutdownProfilerChild"_ns);
+      // If we're not profiling, this operation will be very quick, so it can be
+      // done synchronously. This avoids having to manually shutdown the thread,
+      // which runs a risky inner event loop, see bug 1613798.
+      profilerChildThread->Dispatch(
+          NewRunnableMethod<nsCString*>(
+              "ChildProfilerController::ShutdownProfilerChild SYNC", this,
+              &ChildProfilerController::ShutdownProfilerChild, nullptr),
+          NS_DISPATCH_SYNC);
+    }
+    // At this point, `profilerChildThread` should be the last reference to the
+    // thread, so it will now get destroyed.
+  }
+}
+
+ChildProfilerController::~ChildProfilerController() {
+  MOZ_COUNT_DTOR(ChildProfilerController);
+
+#ifdef DEBUG
+  {
+    auto lock = mThread.Lock();
+    RefPtr<nsIThread>& lockedmThread = lock.ref();
+    MOZ_ASSERT(
+        !lockedmThread,
+        "Please call Shutdown before destroying ChildProfilerController");
+  }
+#endif
+  MOZ_ASSERT(!mProfilerChild);
+}
+
+void ChildProfilerController::SetupProfilerChild(
+    Endpoint<PProfilerChild>&& aEndpoint) {
+  {
+    auto lock = mThread.Lock();
+    RefPtr<nsIThread>& lockedmThread = lock.ref();
+    // We should be on the ProfilerChild thread. In rare cases, we could already
+    // be in shutdown, in which case mThread is null; we still need to continue,
+    // so that ShutdownProfilerChild can work on a valid mProfilerChild.
+    MOZ_RELEASE_ASSERT(!lockedmThread ||
+                       lockedmThread == NS_GetCurrentThread());
+  }
+  MOZ_ASSERT(aEndpoint.IsValid());
+
+  mProfilerChild = new ProfilerChild();
+  Endpoint<PProfilerChild> endpoint = std::move(aEndpoint);
+
+  if (!endpoint.Bind(mProfilerChild)) {
+    MOZ_CRASH("Failed to bind ProfilerChild!");
+  }
+}
+
+void ChildProfilerController::ShutdownProfilerChild(
+    nsCString* aOutShutdownProfile) {
+  const bool isProfiling = profiler_is_active();
+  if (aOutShutdownProfile) {
+    CrashReporter::AnnotateCrashReport(
+        CrashReporter::Annotation::ProfilerChildShutdownPhase,
+        isProfiling ? "Profiling - GrabShutdownProfile"_ns
+                    : "Not profiling - GrabShutdownProfile"_ns);
+    *aOutShutdownProfile = mProfilerChild->GrabShutdownProfile();
+  }
+  CrashReporter::AnnotateCrashReport(
+      CrashReporter::Annotation::ProfilerChildShutdownPhase,
+      isProfiling ? "Profiling - Destroying ProfilerChild"_ns
+                  : "Not profiling - Destroying ProfilerChild"_ns);
+  mProfilerChild->Destroy();
+  mProfilerChild = nullptr;
+  CrashReporter::AnnotateCrashReport(
+      CrashReporter::Annotation::ProfilerChildShutdownPhase,
+      isProfiling
+          ? "Profiling - ShutdownProfilerChild complete, waiting for thread shutdown"_ns
+          : "Not Profiling - ShutdownProfilerChild complete, waiting for thread shutdown"_ns);
+}
+
+}  // namespace mozilla