Bug 1887068: Add perfetto event traces for taskcontroller tasks and dom performance measurement markers. r=smaug

Depends on D205662

Differential Revision: https://phabricator.services.mozilla.com/D205663

dom/performance/Performance.cpp

@@ -33,6 +33,7 @@
 #include "mozilla/dom/PerformanceObserverBinding.h"
 #include "mozilla/dom/PerformanceNavigationTiming.h"
 #include "mozilla/IntegerPrintfMacros.h"
+#include "mozilla/Perfetto.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/TimeStamp.h"
 #include "mozilla/dom/WorkerPrivate.h"
@@ -764,6 +765,25 @@ already_AddRefed<PerformanceMeasure> Performance::Measure(
     detail.setNull();
   }
 
+#ifdef MOZ_PERFETTO
+  // Perfetto requires that events are properly nested within each category.
+  // Since this is not a guarantee here, we need to define a dynamic category
+  // for each measurement so it's not prematurely ended by another measurement
+  // that overlaps.  We also use the usertiming category to guard these markers
+  // so it's easy to toggle.
+  if (TRACE_EVENT_CATEGORY_ENABLED("usertiming")) {
+    NS_ConvertUTF16toUTF8 str(aName);
+    perfetto::DynamicCategory category{str.get()};
+    TimeStamp startTimeStamp =
+        CreationTimeStamp() + TimeDuration::FromMilliseconds(startTime);
+    TimeStamp endTimeStamp =
+        CreationTimeStamp() + TimeDuration::FromMilliseconds(endTime);
+    PERFETTO_TRACE_EVENT_BEGIN(category, perfetto::DynamicString{str.get()},
+                               startTimeStamp);
+    PERFETTO_TRACE_EVENT_END(category, endTimeStamp);
+  }
+#endif
+
   RefPtr<PerformanceMeasure> performanceMeasure = new PerformanceMeasure(
       GetParentObject(), aName, startTime, endTime, detail);
   InsertUserEntry(performanceMeasure);

mozglue/misc/TimeStamp.h

@@ -469,7 +469,7 @@ class TimeStamp {
   static MFBT_API void RecordProcessRestart();
 
 #ifdef XP_LINUX
-  uint64_t RawClockMonotonicNanosecondsSinceBoot() {
+  uint64_t RawClockMonotonicNanosecondsSinceBoot() const {
     return static_cast<uint64_t>(mValue);
   }
 #endif

tools/performance/Perfetto.cpp

@@ -0,0 +1,19 @@
+/* -*- Mode: C++; tab-width: 20; 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 "mozilla/Perfetto.h"
+#include <stdlib.h>
+
+PERFETTO_TRACK_EVENT_STATIC_STORAGE();
+
+void InitPerfetto() {
+  if (!getenv("MOZ_DISABLE_PERFETTO")) {
+    perfetto::TracingInitArgs args;
+    args.backends |= perfetto::kSystemBackend;
+    perfetto::Tracing::Initialize(args);
+    perfetto::TrackEvent::Register();
+  }
+}

tools/performance/Perfetto.h

@@ -0,0 +1,117 @@
+/* -*- 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/. */
+
+#ifndef mozilla_Perfetto_h
+#define mozilla_Perfetto_h
+
+#ifdef MOZ_PERFETTO
+#  include "perfetto/perfetto.h"
+#  include "mozilla/TimeStamp.h"
+
+// Initialization is called when a content process is created.
+// This can be called multiple times.
+extern void InitPerfetto();
+
+/* Perfetto Tracing:
+ *
+ * This file provides an interface to the perfetto tracing API.  The API from
+ * the perfetto sdk can be used directly, but an additional set of macros
+ * prefixed with PERFETTO_* have been defined to help minimize the use of
+ * ifdef's.
+ *
+ * The common perfetto macros require a category and name at the very least.
+ * These must be static strings, or wrapped with perfetto::DynamicString if
+ * dynamic. If the string is static, but provided through a runtime pointer,
+ * then it must be wrapped with perfetto::StaticString.
+ *
+ * You can also provide additional parameters such as a timestamp,
+ * or a lambda to add additional information to the trace marker.
+ * For more info, see https://perfetto.dev/docs/instrumentation/tracing-sdk
+ *
+ * Examples:
+ *
+ *  // Add a trace event to measure work inside a block,
+ *  // using static strings only.
+ *
+ *  {
+ *    PERFETTO_TRACE_EVENT("js", "JS::RunScript");
+ *    run_script();
+ *  }
+ *
+ *  // Add a trace event to measure work inside a block,
+ *  // using a dynamic string.
+ *
+ *  void runScript(nsCString& scriptName)
+ *  {
+ *    PERFETTO_TRACE_EVENT("js", perfetto::DynamicString{scriptName.get()});
+ *    run_script();
+ *  }
+ *
+ *  // Add a trace event using a dynamic category and name.
+ *
+ *  void runScript(nsCString& categoryName, nsCString& scriptName)
+ *  {
+ *    perfetto::DynamicCategory category{category.get()};
+ *    PERFETTO_TRACE_EVENT(category, perfetto::DynamicString{scriptName.get()});
+ *    run_script();
+ *  }
+ *
+ *  // Add a trace event to measure two arbitrary points of code.
+ *  // Events in the same category must always be nested.
+ *
+ *  void startWork() {
+ *    PERFETTO_TRACE_EVENT_BEGIN("js", "StartWork");
+ *    ...
+ *    PERFETTO_TRACE_EVENT_END("js");
+ *  }
+ *
+ *  // Create a trace marker for an event that has already occurred
+ *  // using previously saved timestamps.
+ *
+ *  void record_event(TimeStamp startTimeStamp, TimeStamp endTimeStamp)
+ *  {
+ *    PERFETTO_TRACE_EVENT_BEGIN("js", "Some Event", startTimeStamp);
+ *    PERFETTO_TRACE_EVENT_END("js", endTimeStamp);
+ *  }
+ */
+
+// Wrap the common trace event macros from perfetto so
+// they can be called without #ifdef's.
+#  define PERFETTO_TRACE_EVENT(...) TRACE_EVENT(__VA_ARGS__)
+#  define PERFETTO_TRACE_EVENT_BEGIN(...) TRACE_EVENT_BEGIN(__VA_ARGS__)
+#  define PERFETTO_TRACE_EVENT_END(...) TRACE_EVENT_END(__VA_ARGS__)
+
+namespace perfetto {
+// Specialize custom timestamps for mozilla::TimeStamp.
+template <>
+struct TraceTimestampTraits<mozilla::TimeStamp> {
+  static inline TraceTimestamp ConvertTimestampToTraceTimeNs(
+      const mozilla::TimeStamp& timestamp) {
+    return {protos::gen::BuiltinClock::BUILTIN_CLOCK_MONOTONIC,
+            timestamp.RawClockMonotonicNanosecondsSinceBoot()};
+  }
+};
+}  // namespace perfetto
+
+// Categories can be added dynamically, but to minimize overhead
+// all categories should be pre-defined here whenever possible.
+PERFETTO_DEFINE_CATEGORIES(perfetto::Category("task"),
+                           perfetto::Category("usertiming"));
+
+#else  // !defined(MOZ_PERFETTO)
+#  define PERFETTO_TRACE_EVENT(...) \
+    do {                            \
+    } while (0)
+#  define PERFETTO_TRACE_EVENT_BEGIN(...) \
+    do {                                  \
+    } while (0)
+#  define PERFETTO_TRACE_EVENT_END(...) \
+    do {                                \
+    } while (0)
+inline void InitPerfetto() {}
+#endif  // MOZ_PERFETTO
+
+#endif  // mozilla_Perfetto_h

tools/performance/moz.build

@@ -9,12 +9,14 @@ UNIFIED_SOURCES += [
 ]
 
 EXPORTS.mozilla += [
+    "Perfetto.h",
     "PerfStats.h",
 ]
 
 include("/ipc/chromium/chromium-config.mozbuild")
 
 if CONFIG["MOZ_PERFETTO"]:
+    UNIFIED_SOURCES += ["Perfetto.cpp"]
     DIRS += ["/third_party/perfetto/"]
 
 FINAL_LIBRARY = "xul"

xpcom/threads/TaskController.cpp

@@ -16,6 +16,7 @@
 #include "mozilla/InputTaskManager.h"
 #include "mozilla/VsyncTaskManager.h"
 #include "mozilla/IOInterposer.h"
+#include "mozilla/Perfetto.h"
 #include "mozilla/StaticPtr.h"
 #include "mozilla/SchedulerGroup.h"
 #include "mozilla/ScopeExit.h"
@@ -135,6 +136,7 @@ class MOZ_RAII AutoProfileTask {
 #  define AUTO_PROFILE_FOLLOWING_TASK(task)                                  \
     nsAutoCString name;                                                      \
     (task)->GetName(name);                                                   \
+    PERFETTO_TRACE_EVENT("task", perfetto::DynamicString{name.get()});       \
     AUTO_PROFILER_LABEL_DYNAMIC_NSCSTRING_NONSENSITIVE("Task", OTHER, name); \
     mozilla::AutoProfileTask PROFILER_RAII(name, (task)->GetPriority());
 #else

xpcom/threads/nsThreadManager.cpp

@@ -21,6 +21,7 @@
 #include "mozilla/InputTaskManager.h"
 #include "mozilla/Mutex.h"
 #include "mozilla/NeverDestroyed.h"
+#include "mozilla/Perfetto.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/ProfilerMarkers.h"
 #include "mozilla/SpinEventLoopUntil.h"
@@ -270,6 +271,9 @@ nsThreadManager::nsThreadManager()
 nsThreadManager::~nsThreadManager() = default;
 
 nsresult nsThreadManager::Init() {
+  // Initialize perfetto if on Android.
+  InitPerfetto();
+
   // Child processes need to initialize the thread manager before they
   // initialize XPCOM in order to set up the crash reporter. This leads to
   // situations where we get initialized twice.