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/* -*- 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 */
#ifndef TRACING_H
#define TRACING_H
#include <algorithm>
#include <cstdint>
#include <cstdio>
#include "AsyncLogger.h"
#include "mozilla/Attributes.h"
#include "mozilla/UniquePtr.h"
#if defined(_MSC_VER)
#elif defined(__GNUC__)
// gcc, clang
extern mozilla::AsyncLogger gAudioCallbackTraceLogger;
// This is no-op if tracing is not enabled, and is idempotent.
void StartAudioCallbackTracing();
void StopAudioCallbackTracing();
# define TRACE(aName) AutoTracer trace(gAudioCallbackTraceLogger, aName);
# define TRACE_COMMENT(aName, aFmt, ...) \
AutoTracer trace(gAudioCallbackTraceLogger, aName, \
AutoTracer::EventType::DURATION, aFmt, ##__VA_ARGS__);
# define TRACE_AUDIO_CALLBACK_BUDGET(aFrames, aSampleRate) \
AutoTracer budget(gAudioCallbackTraceLogger, "Real-time budget", \
AutoTracer::EventType::BUDGET, aFrames, aSampleRate);
# define TRACE(aName)
# define TRACE_COMMENT(aFmt, ...)
# define TRACE_AUDIO_CALLBACK_BUDGET(aFrames, aSampleRate)
class MOZ_RAII AutoTracer {
static const int32_t BUFFER_SIZE = 256;
enum class EventType { DURATION, BUDGET };
AutoTracer(mozilla::AsyncLogger& aLogger, const char* aLocation,
EventType aEventType = EventType::DURATION,
const char* aComment = nullptr);
template <typename... Args>
AutoTracer(mozilla::AsyncLogger& aLogger, const char* aLocation,
EventType aEventType, const char* aFormat, Args... aArgs)
: mLogger(aLogger),
mEventType(aEventType) {
MOZ_ASSERT(aEventType == EventType::DURATION);
if (aLogger.Enabled()) {
int32_t size = snprintf(mBuffer, BUFFER_SIZE, aFormat, aArgs...);
size = std::min(size, BUFFER_SIZE - 1);
mBuffer[size] = 0;
PrintEvent(aLocation, "perf", mComment,
AutoTracer(mozilla::AsyncLogger& aLogger, const char* aLocation,
EventType aEventType, uint64_t aFrames, uint64_t aSampleRate);
void PrintEvent(const char* aName, const char* aCategory,
const char* aComment,
mozilla::AsyncLogger::TracingPhase aPhase);
void PrintBudget(const char* aName, const char* aCategory, uint64_t aDuration,
uint64_t aFrames, uint64_t aSampleRate);
// The logger to use. It musdt have a lifetime longer than the block an
// instance of this class traces.
mozilla::AsyncLogger& mLogger;
// The location for this trace point, arbitrary string literal, often the
// name of the calling function, with a static lifetime.
const char* mLocation;
// A comment for this trace point, abitrary string literal with a static
// lifetime.
const char* mComment;
// A buffer used to hold string-formatted traces.
char mBuffer[BUFFER_SIZE];
// The event type, for now either a budget or a duration.
const EventType mEventType;
#endif /* TRACING_H */