content/browser/tracing/power_tracing_agent.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/lazy_instance.h"
   6 #include "base/memory/singleton.h"
   7 #include "base/trace_event/trace_event_impl.h"
   8 #include "content/browser/tracing/battor_power_trace_provider.h"
   9 #include "content/browser/tracing/power_tracing_agent.h"
  10 #include "content/public/browser/browser_thread.h"
  11
  12 namespace content {
  13
  14 PowerTracingAgent::PowerTracingAgent() : is_tracing_(false) {
  15   battor_trace_provider_.reset(new BattorPowerTraceProvider());
  16 }
  17
  18 PowerTracingAgent::~PowerTracingAgent() {}
  19
  20 bool PowerTracingAgent::StartTracing() {
  21   // Tracing session already in progress.
  22   if (is_tracing_)
  23     return false;
  24
  25   // TODO(prabhur) Start tracing probably needs to be done in a
  26   // separate thread since it involves talking to the h/w.
  27   // Revisit once battor h/w communication is enabled.
  28   is_tracing_ = battor_trace_provider_->StartTracing();
  29   return is_tracing_;
  30 }
  31
  32 void PowerTracingAgent::StopTracing(const OutputCallback& callback) {
  33   // No tracing session in progress.
  34   if (!is_tracing_)
  35     return;
  36
  37   // Stop tracing & collect logs.
  38   OutputCallback on_stop_power_tracing_done_callback = base::Bind(
  39       &PowerTracingAgent::OnStopTracingDone, base::Unretained(this), callback);
  40   BrowserThread::PostTask(
  41       BrowserThread::UI, FROM_HERE,
  42       base::Bind(&PowerTracingAgent::FlushOnThread, base::Unretained(this),
  43                  on_stop_power_tracing_done_callback));
  44 }
  45
  46 void PowerTracingAgent::OnStopTracingDone(
  47     const OutputCallback& callback,
  48     const scoped_refptr<base::RefCountedString>& result) {
  49   is_tracing_ = false;
  50   // Pass the serialized events.
  51   callback.Run(result);
  52 }
  53
  54 // static
  55 PowerTracingAgent* PowerTracingAgent::GetInstance() {
  56   return base::Singleton<PowerTracingAgent>::get();
  57 }
  58
  59 void PowerTracingAgent::FlushOnThread(const OutputCallback& callback) {
  60   // Pass the result to the UI Thread.
  61
  62   // TODO(prabhur) StopTracing & GetLog need to be called on a
  63   // separate thread depending on how BattorPowerTraceProvider is implemented.
  64   battor_trace_provider_->StopTracing();
  65   std::string battor_logs;
  66   battor_trace_provider_->GetLog(&battor_logs);
  67   scoped_refptr<base::RefCountedString> result =
  68       base::RefCountedString::TakeString(&battor_logs);
  69   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
  70                           base::Bind(callback, result));
  71 }
  72
  73 }  // namespace content