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/* -*- 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
#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.
*
* 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