1 files changed, 287 insertions, 0 deletions
diff --git a/docshell/base/timeline/TimelineConsumers.cpp b/docshell/base/timeline/TimelineConsumers.cpp
new file mode 100644
index 0000000000..805a54979c
--- /dev/null
+++ b/docshell/base/timeline/TimelineConsumers.cpp
@@ -0,0 +1,287 @@
+/* -*- 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 "TimelineConsumers.h"
+
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/ObservedDocShell.h"
+#include "mozilla/Services.h"
+#include "mozilla/TimelineMarker.h"
+#include "jsapi.h"
+#include "nsAppRunner.h"  // for XRE_IsContentProcess, XRE_IsParentProcess
+#include "nsCRT.h"
+#include "nsDocShell.h"
+#include "nsIObserverService.h"
+
+namespace mozilla {
+
+NS_IMPL_ISUPPORTS(TimelineConsumers, nsIObserver);
+
+StaticMutex TimelineConsumers::sMutex;
+
+// Manually manage this singleton's lifetime and destroy it before shutdown.
+// This avoids the leakchecker detecting false-positive memory leaks when
+// using automatic memory management (i.e. statically instantiating this
+// singleton inside the `Get` method), which would automatically destroy it on
+// application shutdown, but too late for the leakchecker. Sigh...
+StaticRefPtr<TimelineConsumers> TimelineConsumers::sInstance;
+
+// This flag makes sure the singleton never gets instantiated while a shutdown
+// is in progress. This can actually happen, and `ClearOnShutdown` doesn't work
+// in these cases.
+bool TimelineConsumers::sInShutdown = false;
+
+already_AddRefed<TimelineConsumers> TimelineConsumers::Get() {
+  // Using this class is not supported yet for other processes other than
+  // parent or content. To avoid accidental checks to methods like `IsEmpty`,
+  // which would probably always be true in those cases, assert here.
+  // Remember, there will be different singletons available to each process.
+
+  // TODO: we have to avoid calling this function in socket process.
+  MOZ_ASSERT(XRE_IsContentProcess() || XRE_IsParentProcess());
+
+  // If we are shutting down, don't bother doing anything. Note: we can only
+  // know whether or not we're in shutdown if we're instantiated.
+  if (sInShutdown) {
+    return nullptr;
+  }
+
+  // Note: We don't simply check `sInstance` for null-ness here, since otherwise
+  // this can resurrect the TimelineConsumers pretty late during shutdown.
+  // We won't know if we're in shutdown or not though, because the singleton
+  // could have been destroyed or just never instantiated, so in the previous
+  // conditional `sInShutdown` would be false.
+  static bool firstTime = true;
+  if (firstTime) {
+    firstTime = false;
+
+    StaticMutexAutoLock lock(sMutex);
+    sInstance = new TimelineConsumers();
+
+    // Make sure the initialization actually suceeds, otherwise don't allow
+    // access by destroying the instance immediately.
+    if (sInstance->Init()) {
+      ClearOnShutdown(&sInstance);
+    } else {
+      sInstance->RemoveObservers();
+      sInstance = nullptr;
+    }
+  }
+
+  RefPtr<TimelineConsumers> copy = sInstance.get();
+  return copy.forget();
+}
+
+bool TimelineConsumers::Init() {
+  nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
+  if (!obs) {
+    return false;
+  }
+  if (NS_WARN_IF(NS_FAILED(
+          obs->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false)))) {
+    return false;
+  }
+  return true;
+}
+
+bool TimelineConsumers::RemoveObservers() {
+  nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
+  if (!obs) {
+    return false;
+  }
+  if (NS_WARN_IF(NS_FAILED(
+          obs->RemoveObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID)))) {
+    return false;
+  }
+  return true;
+}
+
+nsresult TimelineConsumers::Observe(nsISupports* aSubject, const char* aTopic,
+                                    const char16_t* aData) {
+  if (!nsCRT::strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID)) {
+    sInShutdown = true;
+    RemoveObservers();
+    return NS_OK;
+  }
+
+  MOZ_ASSERT(false, "TimelineConsumers got unexpected topic!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+TimelineConsumers::TimelineConsumers() : mActiveConsumers(0) {}
+
+void TimelineConsumers::AddConsumer(nsDocShell* aDocShell) {
+  MOZ_ASSERT(NS_IsMainThread());
+  StaticMutexAutoLock lock(
+      sMutex);  // for `mActiveConsumers` and `mMarkersStores`.
+
+  UniquePtr<ObservedDocShell>& observed = aDocShell->mObserved;
+  MOZ_ASSERT(!observed);
+
+  if (mActiveConsumers == 0) {
+    JS::SetProfileTimelineRecordingEnabled(true);
+  }
+  mActiveConsumers++;
+
+  ObservedDocShell* obsDocShell = new ObservedDocShell(aDocShell);
+  MarkersStorage* storage = static_cast<MarkersStorage*>(obsDocShell);
+
+  observed.reset(obsDocShell);
+  mMarkersStores.insertFront(storage);
+}
+
+void TimelineConsumers::RemoveConsumer(nsDocShell* aDocShell) {
+  MOZ_ASSERT(NS_IsMainThread());
+  StaticMutexAutoLock lock(
+      sMutex);  // for `mActiveConsumers` and `mMarkersStores`.
+
+  UniquePtr<ObservedDocShell>& observed = aDocShell->mObserved;
+  MOZ_ASSERT(observed);
+
+  mActiveConsumers--;
+  if (mActiveConsumers == 0) {
+    JS::SetProfileTimelineRecordingEnabled(false);
+  }
+
+  // Clear all markers from the `mTimelineMarkers` store.
+  observed.get()->ClearMarkers();
+  // Remove self from the `mMarkersStores` store.
+  observed.get()->remove();
+  // Prepare for becoming a consumer later.
+  observed.reset(nullptr);
+}
+
+bool TimelineConsumers::HasConsumer(nsIDocShell* aDocShell) {
+  MOZ_ASSERT(NS_IsMainThread());
+  return aDocShell ? aDocShell->GetRecordProfileTimelineMarkers() : false;
+}
+
+bool TimelineConsumers::IsEmpty() {
+  StaticMutexAutoLock lock(sMutex);  // for `mActiveConsumers`.
+  return mActiveConsumers == 0;
+}
+
+void TimelineConsumers::AddMarkerForDocShell(nsDocShell* aDocShell,
+                                             const char* aName,
+                                             MarkerTracingType aTracingType,
+                                             MarkerStackRequest aStackRequest) {
+  MOZ_ASSERT(NS_IsMainThread());
+  if (HasConsumer(aDocShell)) {
+    aDocShell->mObserved->AddMarker(
+        MakeUnique<TimelineMarker>(aName, aTracingType, aStackRequest));
+  }
+}
+
+void TimelineConsumers::AddMarkerForDocShell(nsDocShell* aDocShell,
+                                             const char* aName,
+                                             const TimeStamp& aTime,
+                                             MarkerTracingType aTracingType,
+                                             MarkerStackRequest aStackRequest) {
+  MOZ_ASSERT(NS_IsMainThread());
+  if (HasConsumer(aDocShell)) {
+    aDocShell->mObserved->AddMarker(
+        MakeUnique<TimelineMarker>(aName, aTime, aTracingType, aStackRequest));
+  }
+}
+
+void TimelineConsumers::AddMarkerForDocShell(
+    nsDocShell* aDocShell, UniquePtr<AbstractTimelineMarker>&& aMarker) {
+  MOZ_ASSERT(NS_IsMainThread());
+  if (HasConsumer(aDocShell)) {
+    aDocShell->mObserved->AddMarker(std::move(aMarker));
+  }
+}
+
+void TimelineConsumers::AddMarkerForDocShell(nsIDocShell* aDocShell,
+                                             const char* aName,
+                                             MarkerTracingType aTracingType,
+                                             MarkerStackRequest aStackRequest) {
+  MOZ_ASSERT(NS_IsMainThread());
+  AddMarkerForDocShell(static_cast<nsDocShell*>(aDocShell), aName, aTracingType,
+                       aStackRequest);
+}
+
+void TimelineConsumers::AddMarkerForDocShell(nsIDocShell* aDocShell,
+                                             const char* aName,
+                                             const TimeStamp& aTime,
+                                             MarkerTracingType aTracingType,
+                                             MarkerStackRequest aStackRequest) {
+  MOZ_ASSERT(NS_IsMainThread());
+  AddMarkerForDocShell(static_cast<nsDocShell*>(aDocShell), aName, aTime,
+                       aTracingType, aStackRequest);
+}
+
+void TimelineConsumers::AddMarkerForDocShell(
+    nsIDocShell* aDocShell, UniquePtr<AbstractTimelineMarker>&& aMarker) {
+  MOZ_ASSERT(NS_IsMainThread());
+  AddMarkerForDocShell(static_cast<nsDocShell*>(aDocShell), std::move(aMarker));
+}
+
+void TimelineConsumers::AddMarkerForAllObservedDocShells(
+    const char* aName, MarkerTracingType aTracingType,
+    MarkerStackRequest aStackRequest /* = STACK */) {
+  bool isMainThread = NS_IsMainThread();
+  StaticMutexAutoLock lock(sMutex);  // for `mMarkersStores`.
+
+  for (MarkersStorage* storage = mMarkersStores.getFirst(); storage != nullptr;
+       storage = storage->getNext()) {
+    UniquePtr<AbstractTimelineMarker> marker =
+        MakeUnique<TimelineMarker>(aName, aTracingType, aStackRequest);
+    if (isMainThread) {
+      storage->AddMarker(std::move(marker));
+    } else {
+      storage->AddOTMTMarker(std::move(marker));
+    }
+  }
+}
+
+void TimelineConsumers::AddMarkerForAllObservedDocShells(
+    const char* aName, const TimeStamp& aTime, MarkerTracingType aTracingType,
+    MarkerStackRequest aStackRequest /* = STACK */) {
+  bool isMainThread = NS_IsMainThread();
+  StaticMutexAutoLock lock(sMutex);  // for `mMarkersStores`.
+
+  for (MarkersStorage* storage = mMarkersStores.getFirst(); storage != nullptr;
+       storage = storage->getNext()) {
+    UniquePtr<AbstractTimelineMarker> marker =
+        MakeUnique<TimelineMarker>(aName, aTime, aTracingType, aStackRequest);
+    if (isMainThread) {
+      storage->AddMarker(std::move(marker));
+    } else {
+      storage->AddOTMTMarker(std::move(marker));
+    }
+  }
+}
+
+void TimelineConsumers::AddMarkerForAllObservedDocShells(
+    UniquePtr<AbstractTimelineMarker>& aMarker) {
+  bool isMainThread = NS_IsMainThread();
+  StaticMutexAutoLock lock(sMutex);  // for `mMarkersStores`.
+
+  for (MarkersStorage* storage = mMarkersStores.getFirst(); storage != nullptr;
+       storage = storage->getNext()) {
+    UniquePtr<AbstractTimelineMarker> clone = aMarker->Clone();
+    if (isMainThread) {
+      storage->AddMarker(std::move(clone));
+    } else {
+      storage->AddOTMTMarker(std::move(clone));
+    }
+  }
+}
+
+void TimelineConsumers::PopMarkers(
+    nsDocShell* aDocShell, JSContext* aCx,
+    nsTArray<dom::ProfileTimelineMarker>& aStore) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!aDocShell || !aDocShell->mObserved) {
+    return;
+  }
+
+  aDocShell->mObserved->PopMarkers(aCx, aStore);
+}
+
+}  // namespace mozilla