mirror of
https://github.com/klzgrad/naiveproxy.git
synced 2024-11-28 00:06:09 +03:00
97 lines
4.2 KiB
C++
97 lines
4.2 KiB
C++
// Copyright 2015 The Chromium Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style license that can be
|
|
// found in the LICENSE file.
|
|
|
|
#ifndef BASE_TRACE_EVENT_TRACING_AGENT_H_
|
|
#define BASE_TRACE_EVENT_TRACING_AGENT_H_
|
|
|
|
#include "base/base_export.h"
|
|
#include "base/callback.h"
|
|
#include "base/memory/ref_counted_memory.h"
|
|
#include "base/values.h"
|
|
|
|
namespace base {
|
|
|
|
class TimeTicks;
|
|
|
|
namespace trace_event {
|
|
|
|
class TraceConfig;
|
|
|
|
// A tracing agent is an entity that records its own sort of trace. Each
|
|
// tracing method that produces its own trace log should implement this
|
|
// interface. All tracing agents must only be controlled by TracingController.
|
|
// Some existing examples include TracingControllerImpl for Chrome trace events,
|
|
// DebugDaemonClient for CrOs system trace, and EtwTracingAgent for Windows
|
|
// system.
|
|
class BASE_EXPORT TracingAgent {
|
|
public:
|
|
using StartAgentTracingCallback =
|
|
base::OnceCallback<void(const std::string& agent_name, bool success)>;
|
|
// Passing a null or empty events_str_ptr indicates that no trace data is
|
|
// available for the specified agent.
|
|
using StopAgentTracingCallback = base::OnceCallback<void(
|
|
const std::string& agent_name,
|
|
const std::string& events_label,
|
|
const scoped_refptr<base::RefCountedString>& events_str_ptr)>;
|
|
using RecordClockSyncMarkerCallback =
|
|
base::OnceCallback<void(const std::string& sync_id,
|
|
const TimeTicks& issue_ts,
|
|
const TimeTicks& issue_end_ts)>;
|
|
|
|
virtual ~TracingAgent();
|
|
|
|
// Gets the name of the tracing agent. Each tracing agent's name should be
|
|
// unique.
|
|
virtual std::string GetTracingAgentName() = 0;
|
|
|
|
// Gets the trace event label of this tracing agent. The label will be used to
|
|
// label this agent's trace when all traces from different tracing agents are
|
|
// combined. Multiple tracing agents could have the same label. The tracing
|
|
// agents using the same label should not be able to run at the same time. For
|
|
// example, ETW on Windows and CrOS system tracing both use
|
|
// "systemTraceEvents" as the label. Those two agents never run at the same
|
|
// time because they are for different platforms.
|
|
virtual std::string GetTraceEventLabel() = 0;
|
|
|
|
// Starts tracing on the tracing agent with the trace configuration.
|
|
virtual void StartAgentTracing(const TraceConfig& trace_config,
|
|
StartAgentTracingCallback callback) = 0;
|
|
|
|
// Stops tracing on the tracing agent. The trace data will be passed back to
|
|
// the TracingController via the callback.
|
|
virtual void StopAgentTracing(StopAgentTracingCallback callback) = 0;
|
|
|
|
// Checks if the tracing agent supports explicit clock synchronization.
|
|
virtual bool SupportsExplicitClockSync();
|
|
|
|
// Records a clock sync marker issued by another tracing agent. This is only
|
|
// used if the tracing agent supports explicit clock synchronization.
|
|
//
|
|
// Two things need to be done:
|
|
// 1. The issuer asks the receiver to record the clock sync marker.
|
|
// 2. The issuer records how long the receiver takes to do the recording.
|
|
//
|
|
// In Chrome, the receiver thread also runs in Chrome and it will talk to the
|
|
// real receiver entity, e.g., power monitor or Android device system, via
|
|
// different communication methods, e.g., through USB or file reading/writing.
|
|
// The 2nd task measures that communication latency.
|
|
//
|
|
// Having a reliable timing measurement for the 2nd task requires synchronous
|
|
// function call without any cross-thread or cross-process activity. However,
|
|
// tracing agents in Chrome run in their own threads. Therefore, the issuer
|
|
// needs to dedicate the 2nd task to the receiver to take time measurements
|
|
// in the receiver thread, and the receiver thread needs to pass them back to
|
|
// the issuer in the callback.
|
|
//
|
|
// The assumption is that the receiver thread knows the issuer's clock, which
|
|
// is true in Chrome because all agent threads' clocks are Chrome clock.
|
|
virtual void RecordClockSyncMarker(const std::string& sync_id,
|
|
RecordClockSyncMarkerCallback callback);
|
|
};
|
|
|
|
} // namespace trace_event
|
|
} // namespace base
|
|
|
|
#endif // BASE_TRACE_EVENT_TRACING_AGENT_H_
|