1 files changed, 86 insertions, 0 deletions
diff --git a/dom/media/Tracing.cpp b/dom/media/Tracing.cpp
new file mode 100644
index 0000000000..bbab95039c
--- /dev/null
+++ b/dom/media/Tracing.cpp
@@ -0,0 +1,86 @@
+/* -*- Mode: C++; tab-width: 2; 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 "Tracing.h"
+
+#include <inttypes.h>
+
+using namespace mozilla;
+
+using TracingPhase = mozilla::AsyncLogger::TracingPhase;
+
+mozilla::AsyncLogger gAudioCallbackTraceLogger;
+static std::atomic<int> gTracingStarted(0);
+
+void StartAudioCallbackTracing() {
+#ifdef MOZ_REAL_TIME_TRACING
+  int cnt = gTracingStarted.fetch_add(1, std::memory_order_seq_cst);
+  if (cnt == 0) {
+    // This is a noop if the logger has not been enabled.
+    gAudioCallbackTraceLogger.Start();
+  }
+#endif
+}
+
+void StopAudioCallbackTracing() {
+#ifdef MOZ_REAL_TIME_TRACING
+  int cnt = gTracingStarted.fetch_sub(1, std::memory_order_seq_cst);
+  if (cnt == 1) {
+    // This is a noop if the logger has not been enabled.
+    gAudioCallbackTraceLogger.Stop();
+  }
+#endif
+}
+
+void AutoTracer::PrintEvent(const char* aName, const char* aCategory,
+                            const char* aComment, TracingPhase aPhase) {
+#ifdef MOZ_REAL_TIME_TRACING
+  mLogger.Log(aName, aCategory, aComment, aPhase);
+#endif
+}
+
+void AutoTracer::PrintBudget(const char* aName, const char* aCategory,
+                             uint64_t aDuration, uint64_t aFrames,
+                             uint64_t aSampleRate) {
+#ifdef MOZ_REAL_TIME_TRACING
+  mLogger.LogDuration(aName, aCategory, aDuration, aFrames, aSampleRate);
+#endif
+}
+
+AutoTracer::AutoTracer(AsyncLogger& aLogger, const char* aLocation,
+                       EventType aEventType, uint64_t aFrames,
+                       uint64_t aSampleRate)
+    : mLogger(aLogger),
+      mLocation(aLocation),
+      mComment(nullptr),
+      mEventType(aEventType) {
+  MOZ_ASSERT(aEventType == EventType::BUDGET);
+
+  if (aLogger.Enabled()) {
+    float durationUS = (static_cast<float>(aFrames) / aSampleRate) * 1e6;
+    PrintBudget(aLocation, "perf", durationUS, aFrames, aSampleRate);
+  }
+}
+
+AutoTracer::AutoTracer(AsyncLogger& aLogger, const char* aLocation,
+                       EventType aEventType, const char* aComment)
+    : mLogger(aLogger),
+      mLocation(aLocation),
+      mComment(aComment),
+      mEventType(aEventType) {
+  MOZ_ASSERT(aEventType == EventType::DURATION);
+  if (aLogger.Enabled()) {
+    PrintEvent(aLocation, "perf", mComment, AsyncLogger::TracingPhase::BEGIN);
+  }
+}
+
+AutoTracer::~AutoTracer() {
+  if (mEventType == EventType::DURATION) {
+    if (mLogger.Enabled()) {
+      PrintEvent(mLocation, "perf", mComment, AsyncLogger::TracingPhase::END);
+    }
+  }
+}