chromium/base/trace_event/trace_event.h

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_TRACE_EVENT_TRACE_EVENT_H_
#define BASE_TRACE_EVENT_TRACE_EVENT_H_

// This header file defines implementation details of how the trace macros in
// trace_event_common.h collect and store trace events. Anything not
// implementation-specific should go in trace_event_common.h instead of here.

#include <stddef.h>
#include <stdint.h>

#include <memory>
#include <utility>

#include "base/atomicops.h"
#include "base/base_export.h"
#include "base/threading/platform_thread.h"
#include "base/time/time.h"
#include "base/time/time_override.h"
#include "base/trace_event/builtin_categories.h"
#include "base/trace_event/common/trace_event_common.h"  // IWYU pragma: export
#include "base/trace_event/trace_arguments.h"
#include "base/trace_event/trace_category.h"
#include "base/trace_event/trace_log.h"
#include "base/trace_event/traced_value_support.h"
#include "base/tracing_buildflags.h"

// Legacy TRACE_EVENT_API entrypoints. Do not use from new code.

// Add a trace event to the platform tracing system.
// base::trace_event::TraceEventHandle TRACE_EVENT_API_ADD_TRACE_EVENT(
//                    char phase,
//                    const unsigned char* category_group_enabled,
//                    const char* name,
//                    const char* scope,
//                    uint64_t id,
//                    base::trace_event::TraceArguments* args,
//                    unsigned int flags)
#define TRACE_EVENT_API_ADD_TRACE_EVENT …

// Add a trace event to the platform tracing system.
// base::trace_event::TraceEventHandle
// TRACE_EVENT_API_ADD_TRACE_EVENT_WITH_BIND_ID(
//                    char phase,
//                    const unsigned char* category_group_enabled,
//                    const char* name,
//                    const char* scope,
//                    uint64_t id,
//                    uint64_t bind_id,
//                    base::trace_event::TraceArguments* args,
//                    unsigned int flags)
#define TRACE_EVENT_API_ADD_TRACE_EVENT_WITH_BIND_ID …

// Add a trace event to the platform tracing system overriding the pid.
// The resulting event will have tid = pid == (process_id passed here).
// base::trace_event::TraceEventHandle
// TRACE_EVENT_API_ADD_TRACE_EVENT_WITH_PROCESS_ID(
//                    char phase,
//                    const unsigned char* category_group_enabled,
//                    const char* name,
//                    const char* scope,
//                    uint64_t id,
//                    base::ProcessId process_id,
//                    base::trace_event::TraceArguments* args,
//                    unsigned int flags)
#define TRACE_EVENT_API_ADD_TRACE_EVENT_WITH_PROCESS_ID …

// Add a trace event to the platform tracing system.
// base::trace_event::TraceEventHandle
// TRACE_EVENT_API_ADD_TRACE_EVENT_WITH_THREAD_ID_AND_TIMESTAMP(
//                    char phase,
//                    const unsigned char* category_group_enabled,
//                    const char* name,
//                    const char* scope,
//                    uint64_t id,
//                    uint64_t bind_id,
//                    base::PlatformThreadId thread_id,
//                    const TimeTicks& timestamp,
//                    base::trace_event::TraceArguments* args,
//                    unsigned int flags)
#define TRACE_EVENT_API_ADD_TRACE_EVENT_WITH_THREAD_ID_AND_TIMESTAMP …

// Set the duration field of a COMPLETE trace event.
// void TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION(
//     const unsigned char* category_group_enabled,
//     const char* name,
//     base::trace_event::TraceEventHandle id)
#define TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION …

// Adds a metadata event to the trace log. The |AppendValueAsTraceFormat| method
// on the convertable value will be called at flush time.
// TRACE_EVENT_API_ADD_METADATA_EVENT(
//     const unsigned char* category_group_enabled,
//     const char* event_name,
//     const char* arg_name,
//     std::unique_ptr<ConvertableToTraceFormat> arg_value)
#define TRACE_EVENT_API_ADD_METADATA_EVENT …

// Defines atomic operations used internally by the tracing system.
// Acquire/release barriers are important here: crbug.com/1330114#c8.
#define TRACE_EVENT_API_ATOMIC_WORD …
#define TRACE_EVENT_API_ATOMIC_LOAD(var) …
#define TRACE_EVENT_API_ATOMIC_STORE(var, value) …

// Defines visibility for classes in trace_event.h
#define TRACE_EVENT_API_CLASS_EXPORT …

////////////////////////////////////////////////////////////////////////////////

namespace trace_event_internal {

// Specify these values when the corresponding argument of AddTraceEvent is not
// used.
const int kZeroNumArgs = …;
const std::nullptr_t kGlobalScope = …;
const uint64_t kNoId = …;

// TraceID encapsulates an ID that can either be an integer or pointer.
class BASE_EXPORT TraceID { … };

// These functions all internally call
// base::trace_event::TraceLog::GetInstance() then call the method with the same
// name on it. This is used to reduce the generated machine code at each
// TRACE_EVENTXXX macro call.

base::trace_event::TraceEventHandle BASE_EXPORT
AddTraceEvent(char phase,
              const unsigned char* category_group_enabled,
              const char* name,
              const char* scope,
              uint64_t id,
              base::trace_event::TraceArguments* args,
              unsigned int flags);

base::trace_event::TraceEventHandle BASE_EXPORT
AddTraceEventWithBindId(char phase,
                        const unsigned char* category_group_enabled,
                        const char* name,
                        const char* scope,
                        uint64_t id,
                        uint64_t bind_id,
                        base::trace_event::TraceArguments* args,
                        unsigned int flags);

base::trace_event::TraceEventHandle BASE_EXPORT
AddTraceEventWithProcessId(char phase,
                           const unsigned char* category_group_enabled,
                           const char* name,
                           const char* scope,
                           uint64_t id,
                           base::ProcessId process_id,
                           base::trace_event::TraceArguments* args,
                           unsigned int flags);

base::trace_event::TraceEventHandle BASE_EXPORT
AddTraceEventWithThreadIdAndTimestamp(
    char phase,
    const unsigned char* category_group_enabled,
    const char* name,
    const char* scope,
    uint64_t id,
    base::PlatformThreadId thread_id,
    const base::TimeTicks& timestamp,
    base::trace_event::TraceArguments* args,
    unsigned int flags);

base::trace_event::TraceEventHandle BASE_EXPORT
AddTraceEventWithThreadIdAndTimestamp(
    char phase,
    const unsigned char* category_group_enabled,
    const char* name,
    const char* scope,
    uint64_t id,
    uint64_t bind_id,
    base::PlatformThreadId thread_id,
    const base::TimeTicks& timestamp,
    base::trace_event::TraceArguments* args,
    unsigned int flags);

base::trace_event::TraceEventHandle BASE_EXPORT
AddTraceEventWithThreadIdAndTimestamps(
    char phase,
    const unsigned char* category_group_enabled,
    const char* name,
    const char* scope,
    uint64_t id,
    base::PlatformThreadId thread_id,
    const base::TimeTicks& timestamp,
    const base::ThreadTicks& thread_timestamp,
    unsigned int flags);

void BASE_EXPORT AddMetadataEvent(const unsigned char* category_group_enabled,
                                  const char* name,
                                  base::trace_event::TraceArguments* args,
                                  unsigned int flags);

int BASE_EXPORT GetNumTracesRecorded();

void BASE_EXPORT
UpdateTraceEventDuration(const unsigned char* category_group_enabled,
                         const char* name,
                         base::trace_event::TraceEventHandle handle);

void BASE_EXPORT
UpdateTraceEventDurationExplicit(const unsigned char* category_group_enabled,
                                 const char* name,
                                 base::trace_event::TraceEventHandle handle,
                                 base::PlatformThreadId thread_id,
                                 bool explicit_timestamps,
                                 const base::TimeTicks& now,
                                 const base::ThreadTicks& thread_now);

// These AddTraceEvent and AddTraceEventWithThreadIdAndTimestamp template
// functions are defined here instead of in the macro, because the arg_values
// could be temporary objects, such as `std::string`. In order to store
// pointers to the internal c_str and pass through to the tracing API,
// the arg_values must live throughout these procedures.

template <class ARG1_TYPE>
inline base::trace_event::TraceEventHandle
AddTraceEventWithThreadIdAndTimestamp(
    char phase,
    const unsigned char* category_group_enabled,
    const char* name,
    const char* scope,
    uint64_t id,
    base::PlatformThreadId thread_id,
    const base::TimeTicks& timestamp,
    unsigned int flags,
    uint64_t bind_id,
    const char* arg1_name,
    ARG1_TYPE&& arg1_val) { … }

template <class ARG1_TYPE, class ARG2_TYPE>
inline base::trace_event::TraceEventHandle
AddTraceEventWithThreadIdAndTimestamp(
    char phase,
    const unsigned char* category_group_enabled,
    const char* name,
    const char* scope,
    uint64_t id,
    base::PlatformThreadId thread_id,
    const base::TimeTicks& timestamp,
    unsigned int flags,
    uint64_t bind_id,
    const char* arg1_name,
    ARG1_TYPE&& arg1_val,
    const char* arg2_name,
    ARG2_TYPE&& arg2_val) { … }

inline base::trace_event::TraceEventHandle
AddTraceEventWithThreadIdAndTimestamp(
    char phase,
    const unsigned char* category_group_enabled,
    const char* name,
    const char* scope,
    uint64_t id,
    base::PlatformThreadId thread_id,
    const base::TimeTicks& timestamp,
    unsigned int flags,
    uint64_t bind_id) { … }

inline base::trace_event::TraceEventHandle AddTraceEvent(
    char phase,
    const unsigned char* category_group_enabled,
    const char* name,
    const char* scope,
    uint64_t id,
    unsigned int flags,
    uint64_t bind_id) { … }

template <class ARG1_TYPE>
inline base::trace_event::TraceEventHandle AddTraceEvent(
    char phase,
    const unsigned char* category_group_enabled,
    const char* name,
    const char* scope,
    uint64_t id,
    unsigned int flags,
    uint64_t bind_id,
    const char* arg1_name,
    ARG1_TYPE&& arg1_val) { … }

template <class ARG1_TYPE, class ARG2_TYPE>
inline base::trace_event::TraceEventHandle AddTraceEvent(
    char phase,
    const unsigned char* category_group_enabled,
    const char* name,
    const char* scope,
    uint64_t id,
    unsigned int flags,
    uint64_t bind_id,
    const char* arg1_name,
    ARG1_TYPE&& arg1_val,
    const char* arg2_name,
    ARG2_TYPE&& arg2_val) { … }

template <class ARG1_TYPE>
void AddMetadataEvent(const unsigned char* category_group_enabled,
                      const char* event_name,
                      const char* arg_name,
                      ARG1_TYPE&& arg_val) { … }

}  // namespace trace_event_internal

namespace base {
namespace trace_event {

template <typename IDType, const char* category>
class TraceScopedTrackableObject { … };

}  // namespace trace_event
}  // namespace base

#endif  // BASE_TRACE_EVENT_TRACE_EVENT_H_