gecko-dev/dom/media/Tracing.h

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5.4 KiB
C++

/* -*- 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/. */
#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(_WIN32)
#include <process.h>
#define getpid() _getpid()
#else
#include <unistd.h>
#endif
#if defined(_MSC_VER)
// MSVC
#define FUNCTION_SIGNATURE __FUNCSIG__
#elif defined(__GNUC__)
// gcc, clang
#define FUNCTION_SIGNATURE __PRETTY_FUNCTION__
#endif
#ifdef TRACING
/* TRACE is for use in the real-time audio rendering thread.
* It would be better to always pass in the thread id. However, the thread an
* audio callback runs on can change when the underlying audio device change,
* and also it seems to be called from a thread pool in a round-robin fashion
* when audio remoting is activated, making the traces unreadable.
* The thread on which the AudioCallbackDriver::DataCallback is to always
* be thread 0, and the budget is set to always be thread 1. This allows
* displaying those elements in two separate lanes.
* The other thread have "normal" tid. Hashing allows being able to get a
* string representation that is unique and guaranteed to be portable. */
#define TRACE_AUDIO_CALLBACK() \
AutoTracer trace(gMSGTraceLogger, FUNCTION_SIGNATURE, getpid(), 0);
#define TRACE_AUDIO_CALLBACK_BUDGET(aFrames, aSampleRate) \
AutoTracer budget(gMSGTraceLogger, "Real-time budget", getpid(), 1, \
AutoTracer::EventType::BUDGET, aFrames, aSampleRate);
#define TRACE_AUDIO_CALLBACK_COMMENT(aFmt, ...) \
AutoTracer trace(gMSGTraceLogger, FUNCTION_SIGNATURE, getpid(), 0, \
AutoTracer::EventType::DURATION, aFmt, ##__VA_ARGS__);
#define TRACE() \
AutoTracer trace(gMSGTraceLogger, FUNCTION_SIGNATURE, getpid(), \
std::hash<std::thread::id>{}(std::this_thread::get_id()));
#define TRACE_COMMENT(aFmt, ...) \
AutoTracer trace(gMSGTraceLogger, FUNCTION_SIGNATURE, getpid(), \
std::hash<std::thread::id>{}(std::this_thread::get_id()), \
AutoTracer::EventType::DURATION, aFmt, ##__VA_ARGS__);
#else
#define TRACE_AUDIO_CALLBACK()
#define TRACE_AUDIO_CALLBACK_BUDGET(aFrames, aSampleRate)
#define TRACE_AUDIO_CALLBACK_COMMENT(aFmt, ...)
#define TRACE()
#define TRACE_COMMENT(aFmt, ...)
#endif
class MOZ_RAII AutoTracer {
public:
static const int32_t BUFFER_SIZE =
mozilla::AsyncLogger::MAX_MESSAGE_LENGTH / 2;
enum class EventType { DURATION, BUDGET };
AutoTracer(mozilla::AsyncLogger& aLogger, const char* aLocation,
uint64_t aPID, uint64_t aTID,
EventType aEventType = EventType::DURATION,
const char* aComment = nullptr);
template <typename... Args>
AutoTracer(mozilla::AsyncLogger& aLogger, const char* aLocation,
uint64_t aPID, uint64_t aTID, EventType aEventType,
const char* aFormat, Args... aArgs)
: mLogger(aLogger),
mLocation(aLocation),
mComment(mBuffer),
mEventType(aEventType),
mPID(aPID),
mTID(aTID) {
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, TracingPhase::BEGIN, NowInUs(),
aPID, aTID);
}
}
AutoTracer(mozilla::AsyncLogger& aLogger, const char* aLocation,
uint64_t aPID, uint64_t aTID, EventType aEventType,
uint64_t aFrames, uint64_t aSampleRate);
~AutoTracer();
private:
uint64_t NowInUs();
enum class TracingPhase { BEGIN, END, COMPLETE };
const char TRACING_PHASE_STRINGS[3] = {'B', 'E', 'X'};
void PrintEvent(const char* aName, const char* aCategory,
const char* aComment, TracingPhase aPhase, uint64_t aTime,
uint64_t aPID, uint64_t aThread);
void PrintBudget(const char* aName, const char* aCategory, uint64_t aDuration,
uint64_t aPID, uint64_t aThread, 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;
// The process ID of the calling process. Traces are grouped by PID in the
// vizualizer.
const uint64_t mPID;
// The thread ID of the calling thread, will be displayed in a separate
// section in the trace visualizer.
const uint64_t mTID;
};
#if defined(_WIN32)
#undef getpid
#endif
#endif /* TRACING_H */