content/browser/tracing/tracing_controller_impl.cc

// Copyright (c) 2013 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.
#include "content/browser/tracing/tracing_controller_impl.h"

#include "base/bind.h"
#include "base/cpu.h"
#include "base/files/file_util.h"
#include "base/json/string_escape.h"
#include "base/macros.h"
#include "base/strings/string_number_conversions.h"
#include "base/sys_info.h"
#include "base/trace_event/trace_event.h"
#include "build/build_config.h"
#include "content/browser/tracing/file_tracing_provider_impl.h"
#include "content/browser/tracing/power_tracing_agent.h"
#include "content/browser/tracing/trace_message_filter.h"
#include "content/browser/tracing/tracing_ui.h"
#include "content/common/child_process_messages.h"
#include "content/public/browser/browser_message_filter.h"
#include "content/public/browser/content_browser_client.h"
#include "content/public/browser/gpu_data_manager.h"
#include "content/public/browser/tracing_delegate.h"
#include "content/public/common/child_process_host.h"
#include "content/public/common/content_client.h"
#include "content/public/common/content_switches.h"
#include "gpu/config/gpu_info.h"
#include "net/base/network_change_notifier.h"

#if defined(OS_CHROMEOS)
#include "chromeos/dbus/dbus_thread_manager.h"
#include "chromeos/dbus/debug_daemon_client.h"
#endif

#if defined(OS_WIN)
#include "content/browser/tracing/etw_system_event_consumer_win.h"
#endif

using base::trace_event::TraceLog;
using base::trace_event::TraceConfig;

namespace content {

namespace {

base::LazyInstance<TracingControllerImpl>::Leaky g_controller =
    LAZY_INSTANCE_INITIALIZER;

const char kChromeTracingAgentName[] = "chrome";
const char kETWTracingAgentName[] = "etw";
const char kChromeTraceLabel[] = "traceEvents";

const int kIssueClockSyncTimeout = 30;

std::string GetNetworkTypeString() {
  switch (net::NetworkChangeNotifier::GetConnectionType()) {
    case net::NetworkChangeNotifier::CONNECTION_ETHERNET:
      return "Ethernet";
    case net::NetworkChangeNotifier::CONNECTION_WIFI:
      return "WiFi";
    case net::NetworkChangeNotifier::CONNECTION_2G:
      return "2G";
    case net::NetworkChangeNotifier::CONNECTION_3G:
      return "3G";
    case net::NetworkChangeNotifier::CONNECTION_4G:
      return "4G";
    case net::NetworkChangeNotifier::CONNECTION_NONE:
      return "None";
    case net::NetworkChangeNotifier::CONNECTION_BLUETOOTH:
      return "Bluetooth";
    case net::NetworkChangeNotifier::CONNECTION_UNKNOWN:
    default:
      break;
  }
  return "Unknown";
}

scoped_ptr<base::DictionaryValue> GenerateTracingMetadataDict()  {
  scoped_ptr<base::DictionaryValue> metadata_dict(new base::DictionaryValue());

  metadata_dict->SetString("network-type", GetNetworkTypeString());
  metadata_dict->SetString("product-version", GetContentClient()->GetProduct());
  metadata_dict->SetString("user-agent", GetContentClient()->GetUserAgent());

  // OS
  metadata_dict->SetString("os-name", base::SysInfo::OperatingSystemName());
  metadata_dict->SetString("os-version",
                           base::SysInfo::OperatingSystemVersion());
  metadata_dict->SetString("os-arch",
                           base::SysInfo::OperatingSystemArchitecture());

  // CPU
  base::CPU cpu;
  metadata_dict->SetInteger("cpu-family", cpu.family());
  metadata_dict->SetInteger("cpu-model", cpu.model());
  metadata_dict->SetInteger("cpu-stepping", cpu.stepping());
  metadata_dict->SetInteger("num-cpus", base::SysInfo::NumberOfProcessors());
  metadata_dict->SetInteger("physical-memory",
                            base::SysInfo::AmountOfPhysicalMemoryMB());

  std::string cpu_brand = cpu.cpu_brand();
  // Workaround for crbug.com/249713.
  // TODO(oysteine): Remove workaround when bug is fixed.
  size_t null_pos = cpu_brand.find('\0');
  if (null_pos != std::string::npos)
    cpu_brand.erase(null_pos);
  metadata_dict->SetString("cpu-brand", cpu_brand);

  // GPU
  gpu::GPUInfo gpu_info = content::GpuDataManager::GetInstance()->GetGPUInfo();

#if !defined(OS_ANDROID)
  metadata_dict->SetInteger("gpu-venid", gpu_info.gpu.vendor_id);
  metadata_dict->SetInteger("gpu-devid", gpu_info.gpu.device_id);
#endif

  metadata_dict->SetString("gpu-driver", gpu_info.driver_version);
  metadata_dict->SetString("gpu-psver", gpu_info.pixel_shader_version);
  metadata_dict->SetString("gpu-vsver", gpu_info.vertex_shader_version);

#if defined(OS_MACOSX)
  metadata_dict->SetString("gpu-glver", gpu_info.gl_version);
#elif defined(OS_POSIX)
  metadata_dict->SetString("gpu-gl-vendor", gpu_info.gl_vendor);
  metadata_dict->SetString("gpu-gl-renderer", gpu_info.gl_renderer);
#endif

  scoped_ptr<TracingDelegate> delegate(
      GetContentClient()->browser()->GetTracingDelegate());
  if (delegate)
    delegate->GenerateMetadataDict(metadata_dict.get());

  // Highres ticks.
  metadata_dict->SetBoolean("highres-ticks",
                            base::TimeTicks::IsHighResolution());

  return metadata_dict;
}

}  // namespace

TracingController* TracingController::GetInstance() {
  return TracingControllerImpl::GetInstance();
}

TracingControllerImpl::TracingControllerImpl()
    : pending_stop_tracing_ack_count_(0),
      pending_capture_monitoring_snapshot_ack_count_(0),
      pending_trace_log_status_ack_count_(0),
      maximum_trace_buffer_usage_(0),
      approximate_event_count_(0),
      pending_memory_dump_ack_count_(0),
      failed_memory_dump_count_(0),
      clock_sync_id_(0),
      pending_clock_sync_ack_count_(0),
      is_tracing_(false),
      is_monitoring_(false) {
  base::trace_event::MemoryDumpManager::GetInstance()->Initialize(
      this /* delegate */, true /* is_coordinator */);

  // Deliberately leaked, like this class.
  base::FileTracing::SetProvider(new FileTracingProviderImpl);
}

TracingControllerImpl::~TracingControllerImpl() {
  // This is a Leaky instance.
  NOTREACHED();
}

TracingControllerImpl* TracingControllerImpl::GetInstance() {
  return g_controller.Pointer();
}

bool TracingControllerImpl::GetCategories(
    const GetCategoriesDoneCallback& callback) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  // Known categories come back from child processes with the EndTracingAck
  // message. So to get known categories, just begin and end tracing immediately
  // afterwards. This will ping all the child processes for categories.
  pending_get_categories_done_callback_ = callback;
  if (!StartTracing(TraceConfig("*", ""), StartTracingDoneCallback())) {
    pending_get_categories_done_callback_.Reset();
    return false;
  }

  bool ok = StopTracing(NULL);
  DCHECK(ok);
  return true;
}

void TracingControllerImpl::SetEnabledOnFileThread(
    const TraceConfig& trace_config,
    int mode,
    const base::Closure& callback) {
  DCHECK_CURRENTLY_ON(BrowserThread::FILE);

  TraceLog::GetInstance()->SetEnabled(
      trace_config, static_cast<TraceLog::Mode>(mode));
  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, callback);
}

void TracingControllerImpl::SetDisabledOnFileThread(
    const base::Closure& callback) {
  DCHECK_CURRENTLY_ON(BrowserThread::FILE);

  TraceLog::GetInstance()->SetDisabled();
  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, callback);
}

bool TracingControllerImpl::StartTracing(
    const TraceConfig& trace_config,
    const StartTracingDoneCallback& callback) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  DCHECK(additional_tracing_agents_.empty());

  if (!can_start_tracing())
    return false;
  is_tracing_ = true;
  start_tracing_done_callback_ = callback;

#if defined(OS_ANDROID)
  if (pending_get_categories_done_callback_.is_null())
    TraceLog::GetInstance()->AddClockSyncMetadataEvent();
#endif

  if (trace_config.IsSystraceEnabled()) {
    if (PowerTracingAgent::GetInstance()->StartAgentTracing(trace_config))
      additional_tracing_agents_.push_back(PowerTracingAgent::GetInstance());
#if defined(OS_CHROMEOS)
    chromeos::DebugDaemonClient* debug_daemon =
        chromeos::DBusThreadManager::Get()->GetDebugDaemonClient();
    if (debug_daemon && debug_daemon->StartAgentTracing(trace_config)) {
      debug_daemon->SetStopAgentTracingTaskRunner(
          BrowserThread::GetBlockingPool());
      additional_tracing_agents_.push_back(
          chromeos::DBusThreadManager::Get()->GetDebugDaemonClient());
    }
#elif defined(OS_WIN)
    if (EtwSystemEventConsumer::GetInstance()->StartAgentTracing(
        trace_config)) {
      additional_tracing_agents_.push_back(
          EtwSystemEventConsumer::GetInstance());
    }
#endif
  }

  // TraceLog may have been enabled in startup tracing before threads are ready.
  if (TraceLog::GetInstance()->IsEnabled())
    return true;
  return StartAgentTracing(trace_config);
}

void TracingControllerImpl::OnStartAgentTracingDone(
    const TraceConfig& trace_config,
    const StartTracingDoneCallback& callback) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  TRACE_EVENT_API_ADD_METADATA_EVENT("IsTimeTicksHighResolution", "value",
                                     base::TimeTicks::IsHighResolution());
  TRACE_EVENT_API_ADD_METADATA_EVENT("TraceConfig", "value",
                                     trace_config.AsConvertableToTraceFormat());

  // Notify all child processes.
  for (TraceMessageFilterSet::iterator it = trace_message_filters_.begin();
      it != trace_message_filters_.end(); ++it) {
    it->get()->SendBeginTracing(trace_config);
  }

  if (!callback.is_null())
    callback.Run();
}

bool TracingControllerImpl::StopTracing(
    const scoped_refptr<TraceDataSink>& trace_data_sink) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  if (trace_data_sink) {
    if (TraceLog::GetInstance()->GetCurrentTraceConfig()
        .IsArgumentFilterEnabled()) {
      scoped_ptr<TracingDelegate> delegate(
          GetContentClient()->browser()->GetTracingDelegate());
      if (delegate) {
        trace_data_sink->SetMetadataFilterPredicate(
            delegate->GetMetadataFilterPredicate());
      }
    }
    trace_data_sink->AddMetadata(*GenerateTracingMetadataDict().get());
  }

  if (!can_stop_tracing())
    return false;

  trace_data_sink_ = trace_data_sink;

  // Issue clock sync marker before actually stopping tracing.
  // StopTracingAfterClockSync() will be called after clock sync is done.
  IssueClockSyncMarker();

  return true;
}

void TracingControllerImpl::StopTracingAfterClockSync() {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  // |pending_clock_sync_ack_count_| could be non-zero if clock sync times out.
  pending_clock_sync_ack_count_ = 0;

  // Disable local trace early to avoid traces during end-tracing process from
  // interfering with the process.
  base::Closure on_stop_tracing_done_callback = base::Bind(
      &TracingControllerImpl::OnStopTracingDone, base::Unretained(this));
  BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
      base::Bind(&TracingControllerImpl::SetDisabledOnFileThread,
                 base::Unretained(this),
                 on_stop_tracing_done_callback));
}

void TracingControllerImpl::OnStopTracingDone() {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

#if defined(OS_ANDROID)
  if (pending_get_categories_done_callback_.is_null())
    TraceLog::GetInstance()->AddClockSyncMetadataEvent();
#endif

  // Count myself (local trace) in pending_stop_tracing_ack_count_,
  // acked below.
  pending_stop_tracing_ack_count_ = trace_message_filters_.size() + 1;
  pending_stop_tracing_filters_ = trace_message_filters_;

  pending_stop_tracing_ack_count_ += additional_tracing_agents_.size();
  for (auto it : additional_tracing_agents_) {
    it->StopAgentTracing(
        base::Bind(&TracingControllerImpl::OnEndAgentTracingAcked,
                   base::Unretained(this)));
  }
  additional_tracing_agents_.clear();

  StopAgentTracing(StopAgentTracingCallback());
}

bool TracingControllerImpl::StartMonitoring(
    const TraceConfig& trace_config,
    const StartMonitoringDoneCallback& callback) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  if (!can_start_monitoring())
    return false;
  OnMonitoringStateChanged(true);

#if defined(OS_ANDROID)
  TraceLog::GetInstance()->AddClockSyncMetadataEvent();
#endif

  base::Closure on_start_monitoring_done_callback =
      base::Bind(&TracingControllerImpl::OnStartMonitoringDone,
                 base::Unretained(this),
                 trace_config, callback);
  if (!BrowserThread::PostTask(
          BrowserThread::FILE, FROM_HERE,
          base::Bind(&TracingControllerImpl::SetEnabledOnFileThread,
                     base::Unretained(this), trace_config,
                     base::trace_event::TraceLog::MONITORING_MODE,
                     on_start_monitoring_done_callback))) {
    // BrowserThread::PostTask fails if the threads haven't been created yet,
    // so it should be safe to just use TraceLog::SetEnabled directly.
    base::trace_event::TraceLog::GetInstance()->SetEnabled(
        trace_config, base::trace_event::TraceLog::MONITORING_MODE);
    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
                            on_start_monitoring_done_callback);
  }
  return true;
}

void TracingControllerImpl::OnStartMonitoringDone(
    const TraceConfig& trace_config,
    const StartMonitoringDoneCallback& callback) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  // Notify all child processes.
  for (TraceMessageFilterSet::iterator it = trace_message_filters_.begin();
      it != trace_message_filters_.end(); ++it) {
    it->get()->SendStartMonitoring(trace_config);
  }

  if (!callback.is_null())
    callback.Run();
}

bool TracingControllerImpl::StopMonitoring(
    const StopMonitoringDoneCallback& callback) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  if (!can_stop_monitoring())
    return false;

  base::Closure on_stop_monitoring_done_callback =
      base::Bind(&TracingControllerImpl::OnStopMonitoringDone,
                 base::Unretained(this), callback);
  BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
      base::Bind(&TracingControllerImpl::SetDisabledOnFileThread,
                 base::Unretained(this),
                 on_stop_monitoring_done_callback));
  return true;
}

void TracingControllerImpl::OnStopMonitoringDone(
    const StopMonitoringDoneCallback& callback) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  OnMonitoringStateChanged(false);

  // Notify all child processes.
  for (TraceMessageFilterSet::iterator it = trace_message_filters_.begin();
      it != trace_message_filters_.end(); ++it) {
    it->get()->SendStopMonitoring();
  }
  if (!callback.is_null())
    callback.Run();
}

void TracingControllerImpl::GetMonitoringStatus(
    bool* out_enabled,
    TraceConfig* out_trace_config) {
  *out_enabled = is_monitoring_;
  *out_trace_config = TraceLog::GetInstance()->GetCurrentTraceConfig();
}

bool TracingControllerImpl::CaptureMonitoringSnapshot(
    const scoped_refptr<TraceDataSink>& monitoring_data_sink) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  if (!can_stop_monitoring())
    return false;

  if (!monitoring_data_sink.get())
    return false;

  monitoring_data_sink_ = monitoring_data_sink;

  // Count myself in pending_capture_monitoring_snapshot_ack_count_,
  // acked below.
  pending_capture_monitoring_snapshot_ack_count_ =
      trace_message_filters_.size() + 1;
  pending_capture_monitoring_filters_ = trace_message_filters_;

  // Handle special case of zero child processes by immediately flushing the
  // trace log. Once the flush has completed the caller will be notified that
  // the capture snapshot has ended.
  if (pending_capture_monitoring_snapshot_ack_count_ == 1) {
    // Flush asynchronously now, because we don't have any children to wait for.
    TraceLog::GetInstance()->FlushButLeaveBufferIntact(
        base::Bind(&TracingControllerImpl::OnLocalMonitoringTraceDataCollected,
                   base::Unretained(this)));
  }

  // Notify all child processes.
  for (TraceMessageFilterSet::iterator it = trace_message_filters_.begin();
      it != trace_message_filters_.end(); ++it) {
    it->get()->SendCaptureMonitoringSnapshot();
  }

#if defined(OS_ANDROID)
  TraceLog::GetInstance()->AddClockSyncMetadataEvent();
#endif

  return true;
}

bool TracingControllerImpl::GetTraceBufferUsage(
    const GetTraceBufferUsageCallback& callback) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  if (!can_get_trace_buffer_usage() || callback.is_null())
    return false;

  pending_trace_buffer_usage_callback_ = callback;

  // Count myself in pending_trace_log_status_ack_count_, acked below.
  pending_trace_log_status_ack_count_ = trace_message_filters_.size() + 1;
  pending_trace_log_status_filters_ = trace_message_filters_;
  maximum_trace_buffer_usage_ = 0;
  approximate_event_count_ = 0;

  base::trace_event::TraceLogStatus status =
      TraceLog::GetInstance()->GetStatus();
  // Call OnTraceLogStatusReply unconditionally for the browser process.
  // This will result in immediate execution of the callback if there are no
  // child processes.
  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      base::Bind(&TracingControllerImpl::OnTraceLogStatusReply,
                 base::Unretained(this), scoped_refptr<TraceMessageFilter>(),
                 status));

  // Notify all child processes.
  for (TraceMessageFilterSet::iterator it = trace_message_filters_.begin();
      it != trace_message_filters_.end(); ++it) {
    it->get()->SendGetTraceLogStatus();
  }
  return true;
}

bool TracingControllerImpl::SetWatchEvent(
    const std::string& category_name,
    const std::string& event_name,
    const WatchEventCallback& callback) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  if (callback.is_null())
    return false;

  watch_category_name_ = category_name;
  watch_event_name_ = event_name;
  watch_event_callback_ = callback;

  TraceLog::GetInstance()->SetWatchEvent(
      category_name, event_name,
      base::Bind(&TracingControllerImpl::OnWatchEventMatched,
                 base::Unretained(this)));

  for (TraceMessageFilterSet::iterator it = trace_message_filters_.begin();
      it != trace_message_filters_.end(); ++it) {
    it->get()->SendSetWatchEvent(category_name, event_name);
  }
  return true;
}

bool TracingControllerImpl::CancelWatchEvent() {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  if (!can_cancel_watch_event())
    return false;

  for (TraceMessageFilterSet::iterator it = trace_message_filters_.begin();
      it != trace_message_filters_.end(); ++it) {
    it->get()->SendCancelWatchEvent();
  }

  watch_event_callback_.Reset();
  return true;
}

bool TracingControllerImpl::IsTracing() const {
  return is_tracing_;
}

void TracingControllerImpl::AddTraceMessageFilter(
    TraceMessageFilter* trace_message_filter) {
  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
        base::Bind(&TracingControllerImpl::AddTraceMessageFilter,
                   base::Unretained(this),
                   make_scoped_refptr(trace_message_filter)));
    return;
  }

  trace_message_filters_.insert(trace_message_filter);
  if (can_cancel_watch_event()) {
    trace_message_filter->SendSetWatchEvent(watch_category_name_,
                                            watch_event_name_);
  }
  if (can_stop_tracing()) {
    trace_message_filter->SendBeginTracing(
        TraceLog::GetInstance()->GetCurrentTraceConfig());
  }
  if (can_stop_monitoring()) {
    trace_message_filter->SendStartMonitoring(
        TraceLog::GetInstance()->GetCurrentTraceConfig());
  }

  FOR_EACH_OBSERVER(TraceMessageFilterObserver, trace_message_filter_observers_,
                    OnTraceMessageFilterAdded(trace_message_filter));
}

void TracingControllerImpl::RemoveTraceMessageFilter(
    TraceMessageFilter* trace_message_filter) {
  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
        base::Bind(&TracingControllerImpl::RemoveTraceMessageFilter,
                   base::Unretained(this),
                   make_scoped_refptr(trace_message_filter)));
    return;
  }

  // If a filter is removed while a response from that filter is pending then
  // simulate the response. Otherwise the response count will be wrong and the
  // completion callback will never be executed.
  if (pending_stop_tracing_ack_count_ > 0) {
    TraceMessageFilterSet::const_iterator it =
        pending_stop_tracing_filters_.find(trace_message_filter);
    if (it != pending_stop_tracing_filters_.end()) {
      BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
          base::Bind(&TracingControllerImpl::OnStopTracingAcked,
                     base::Unretained(this),
                     make_scoped_refptr(trace_message_filter),
                     std::vector<std::string>()));
    }
  }
  if (pending_capture_monitoring_snapshot_ack_count_ > 0) {
    TraceMessageFilterSet::const_iterator it =
        pending_capture_monitoring_filters_.find(trace_message_filter);
    if (it != pending_capture_monitoring_filters_.end()) {
      BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
          base::Bind(&TracingControllerImpl::OnCaptureMonitoringSnapshotAcked,
                     base::Unretained(this),
                     make_scoped_refptr(trace_message_filter)));
    }
  }
  if (pending_trace_log_status_ack_count_ > 0) {
    TraceMessageFilterSet::const_iterator it =
        pending_trace_log_status_filters_.find(trace_message_filter);
    if (it != pending_trace_log_status_filters_.end()) {
      BrowserThread::PostTask(
          BrowserThread::UI, FROM_HERE,
          base::Bind(&TracingControllerImpl::OnTraceLogStatusReply,
                     base::Unretained(this),
                     make_scoped_refptr(trace_message_filter),
                     base::trace_event::TraceLogStatus()));
    }
  }
  if (pending_memory_dump_ack_count_ > 0) {
    TraceMessageFilterSet::const_iterator it =
        pending_memory_dump_filters_.find(trace_message_filter);
    if (it != pending_memory_dump_filters_.end()) {
      BrowserThread::PostTask(
          BrowserThread::UI, FROM_HERE,
          base::Bind(&TracingControllerImpl::OnProcessMemoryDumpResponse,
                     base::Unretained(this),
                     make_scoped_refptr(trace_message_filter),
                     pending_memory_dump_guid_, false /* success */));
    }
  }
  trace_message_filters_.erase(trace_message_filter);
}

void TracingControllerImpl::OnStopTracingAcked(
    TraceMessageFilter* trace_message_filter,
    const std::vector<std::string>& known_category_groups) {
  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
        base::Bind(&TracingControllerImpl::OnStopTracingAcked,
                   base::Unretained(this),
                   make_scoped_refptr(trace_message_filter),
                   known_category_groups));
    return;
  }

  // Merge known_category_groups with known_category_groups_
  known_category_groups_.insert(known_category_groups.begin(),
                                known_category_groups.end());

  if (pending_stop_tracing_ack_count_ == 0)
    return;

  if (trace_message_filter &&
      !pending_stop_tracing_filters_.erase(trace_message_filter)) {
    // The response from the specified message filter has already been received.
    return;
  }

  if (--pending_stop_tracing_ack_count_ == 1) {
    // All acks from subprocesses have been received. Now flush the local trace.
    // During or after this call, our OnLocalTraceDataCollected will be
    // called with the last of the local trace data.
    if (trace_data_sink_) {
    TraceLog::GetInstance()->Flush(
        base::Bind(&TracingControllerImpl::OnLocalTraceDataCollected,
                   base::Unretained(this)),
        true);
    } else {
      TraceLog::GetInstance()->CancelTracing(
          base::Bind(&TracingControllerImpl::OnLocalTraceDataCollected,
                     base::Unretained(this)));
    }
    return;
  }

  if (pending_stop_tracing_ack_count_ != 0)
    return;

  // All acks (including from the subprocesses and the local trace) have been
  // received.
  is_tracing_ = false;

  // Trigger callback if one is set.
  if (!pending_get_categories_done_callback_.is_null()) {
    pending_get_categories_done_callback_.Run(known_category_groups_);
    pending_get_categories_done_callback_.Reset();
  } else if (trace_data_sink_.get()) {
    trace_data_sink_->Close();
    trace_data_sink_ = NULL;
  }
}

void TracingControllerImpl::OnEndAgentTracingAcked(
    const std::string& agent_name,
    const std::string& events_label,
    const scoped_refptr<base::RefCountedString>& events_str_ptr) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  if (trace_data_sink_.get()) {
    std::string json_string;
    if (agent_name == kETWTracingAgentName) {
      // The Windows kernel events are kept into a JSON format stored as string
      // and must not be escaped.
      json_string = events_str_ptr->data();
    } else {
      json_string = base::GetQuotedJSONString(events_str_ptr->data());
    }
    trace_data_sink_->AddAgentTrace(events_label, json_string);
  }
  std::vector<std::string> category_groups;
  OnStopTracingAcked(NULL, category_groups);
}

void TracingControllerImpl::OnCaptureMonitoringSnapshotAcked(
    TraceMessageFilter* trace_message_filter) {
  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
        base::Bind(&TracingControllerImpl::OnCaptureMonitoringSnapshotAcked,
                   base::Unretained(this),
                   make_scoped_refptr(trace_message_filter)));
    return;
  }

  if (pending_capture_monitoring_snapshot_ack_count_ == 0)
    return;

  if (trace_message_filter &&
      !pending_capture_monitoring_filters_.erase(trace_message_filter)) {
    // The response from the specified message filter has already been received.
    return;
  }

  if (--pending_capture_monitoring_snapshot_ack_count_ == 1) {
    // All acks from subprocesses have been received. Now flush the local trace.
    // During or after this call, our OnLocalMonitoringTraceDataCollected
    // will be called with the last of the local trace data.
    TraceLog::GetInstance()->FlushButLeaveBufferIntact(
        base::Bind(&TracingControllerImpl::OnLocalMonitoringTraceDataCollected,
                   base::Unretained(this)));
    return;
  }

  if (pending_capture_monitoring_snapshot_ack_count_ != 0)
    return;

  if (monitoring_data_sink_.get()) {
    monitoring_data_sink_->Close();
    monitoring_data_sink_ = NULL;
  }
}

void TracingControllerImpl::OnTraceDataCollected(
    const scoped_refptr<base::RefCountedString>& events_str_ptr) {
  // OnTraceDataCollected may be called from any browser thread, either by the
  // local event trace system or from child processes via TraceMessageFilter.
  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
        base::Bind(&TracingControllerImpl::OnTraceDataCollected,
                   base::Unretained(this), events_str_ptr));
    return;
  }

  if (trace_data_sink_.get())
    trace_data_sink_->AddTraceChunk(events_str_ptr->data());
}

void TracingControllerImpl::OnMonitoringTraceDataCollected(
    const scoped_refptr<base::RefCountedString>& events_str_ptr) {
  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
        base::Bind(&TracingControllerImpl::OnMonitoringTraceDataCollected,
                   base::Unretained(this), events_str_ptr));
    return;
  }

  if (monitoring_data_sink_.get())
    monitoring_data_sink_->AddTraceChunk(events_str_ptr->data());
}

void TracingControllerImpl::OnLocalTraceDataCollected(
    const scoped_refptr<base::RefCountedString>& events_str_ptr,
    bool has_more_events) {
  if (events_str_ptr->data().size())
    OnTraceDataCollected(events_str_ptr);

  if (has_more_events)
    return;

  // Simulate an StopTracingAcked for the local trace.
  std::vector<std::string> category_groups;
  TraceLog::GetInstance()->GetKnownCategoryGroups(&category_groups);
  OnStopTracingAcked(NULL, category_groups);
}

void TracingControllerImpl::OnLocalMonitoringTraceDataCollected(
    const scoped_refptr<base::RefCountedString>& events_str_ptr,
    bool has_more_events) {
  if (events_str_ptr->data().size())
    OnMonitoringTraceDataCollected(events_str_ptr);

  if (has_more_events)
    return;

  // Simulate an CaptureMonitoringSnapshotAcked for the local trace.
  OnCaptureMonitoringSnapshotAcked(NULL);
}

void TracingControllerImpl::OnTraceLogStatusReply(
    TraceMessageFilter* trace_message_filter,
    const base::trace_event::TraceLogStatus& status) {
  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(
        BrowserThread::UI, FROM_HERE,
        base::Bind(&TracingControllerImpl::OnTraceLogStatusReply,
                   base::Unretained(this),
                   make_scoped_refptr(trace_message_filter), status));
    return;
  }

  if (pending_trace_log_status_ack_count_ == 0)
    return;

  if (trace_message_filter &&
      !pending_trace_log_status_filters_.erase(trace_message_filter)) {
    // The response from the specified message filter has already been received.
    return;
  }

  float percent_full = static_cast<float>(
      static_cast<double>(status.event_count) / status.event_capacity);
  maximum_trace_buffer_usage_ =
      std::max(maximum_trace_buffer_usage_, percent_full);
  approximate_event_count_ += status.event_count;

  if (--pending_trace_log_status_ack_count_ == 0) {
    // Trigger callback if one is set.
    pending_trace_buffer_usage_callback_.Run(maximum_trace_buffer_usage_,
                                             approximate_event_count_);
    pending_trace_buffer_usage_callback_.Reset();
  }
}

void TracingControllerImpl::OnWatchEventMatched() {
  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
        base::Bind(&TracingControllerImpl::OnWatchEventMatched,
                   base::Unretained(this)));
    return;
  }

  if (!watch_event_callback_.is_null())
    watch_event_callback_.Run();
}

void TracingControllerImpl::RegisterTracingUI(TracingUI* tracing_ui) {
  DCHECK(tracing_uis_.find(tracing_ui) == tracing_uis_.end());
  tracing_uis_.insert(tracing_ui);
}

void TracingControllerImpl::UnregisterTracingUI(TracingUI* tracing_ui) {
  std::set<TracingUI*>::iterator it = tracing_uis_.find(tracing_ui);
  DCHECK(it != tracing_uis_.end());
  tracing_uis_.erase(it);
}

std::string TracingControllerImpl::GetTracingAgentName() {
  return kChromeTracingAgentName;
}

std::string TracingControllerImpl::GetTraceEventLabel() {
  return kChromeTraceLabel;
}

bool TracingControllerImpl::StartAgentTracing(
    const base::trace_event::TraceConfig& trace_config) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  base::Closure on_start_tracing_done_callback =
      base::Bind(&TracingControllerImpl::OnStartAgentTracingDone,
                 base::Unretained(this),
                 trace_config, start_tracing_done_callback_);
  if (!BrowserThread::PostTask(
          BrowserThread::FILE, FROM_HERE,
          base::Bind(&TracingControllerImpl::SetEnabledOnFileThread,
                     base::Unretained(this), trace_config,
                     base::trace_event::TraceLog::RECORDING_MODE,
                     on_start_tracing_done_callback))) {
    // BrowserThread::PostTask fails if the threads haven't been created yet,
    // so it should be safe to just use TraceLog::SetEnabled directly.
    base::trace_event::TraceLog::GetInstance()->SetEnabled(
        trace_config, base::trace_event::TraceLog::RECORDING_MODE);
    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
                            on_start_tracing_done_callback);
  }

  return true;
}

void TracingControllerImpl::StopAgentTracing(
    const StopAgentTracingCallback& callback) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  // Handle special case of zero child processes by immediately flushing the
  // trace log. Once the flush has completed the caller will be notified that
  // tracing has ended.
  if (pending_stop_tracing_ack_count_ == 1) {
    // Flush/cancel asynchronously now, because we don't have any children to
    // wait for.
    if (trace_data_sink_) {
      TraceLog::GetInstance()->Flush(
          base::Bind(&TracingControllerImpl::OnLocalTraceDataCollected,
                     base::Unretained(this)),
          true);
    } else {
      TraceLog::GetInstance()->CancelTracing(
          base::Bind(&TracingControllerImpl::OnLocalTraceDataCollected,
                     base::Unretained(this)));
    }
  }

  // Notify all child processes.
  for (auto it : trace_message_filters_) {
    if (trace_data_sink_)
      it->SendEndTracing();
    else
      it->SendCancelTracing();
  }
}

bool TracingControllerImpl::SupportsExplicitClockSync() {
  return true;
}

void TracingControllerImpl::RecordClockSyncMarker(
    int sync_id,
    const RecordClockSyncMarkerCallback& callback) {
  DCHECK(SupportsExplicitClockSync());

  TRACE_EVENT_CLOCK_SYNC_RECEIVER(sync_id);
}

int TracingControllerImpl::GetUniqueClockSyncID() {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  // There is no need to lock because this function only runs on UI thread.
  return ++clock_sync_id_;
}

void TracingControllerImpl::IssueClockSyncMarker() {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  DCHECK(pending_clock_sync_ack_count_ == 0);

  for (const auto& it : additional_tracing_agents_) {
    if (it->SupportsExplicitClockSync()) {
      it->RecordClockSyncMarker(
          GetUniqueClockSyncID(),
          base::Bind(&TracingControllerImpl::OnClockSyncMarkerRecordedByAgent,
                     base::Unretained(this)));
      pending_clock_sync_ack_count_++;
    }
  }

  // If no clock sync is needed, stop tracing right away. Otherwise, schedule
  // to stop tracing after timeout.
  if (pending_clock_sync_ack_count_ == 0) {
    StopTracingAfterClockSync();
  } else {
    clock_sync_timer_.Start(
        FROM_HERE,
        base::TimeDelta::FromSeconds(kIssueClockSyncTimeout),
        this,
        &TracingControllerImpl::StopTracingAfterClockSync);
  }
}

void TracingControllerImpl::OnClockSyncMarkerRecordedByAgent(
    int sync_id,
    const base::TimeTicks& issue_ts,
    const base::TimeTicks& issue_end_ts) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  TRACE_EVENT_CLOCK_SYNC_ISSUER(sync_id, issue_ts, issue_end_ts);

  // Timer is not running means that clock sync already timed out.
  if (!clock_sync_timer_.IsRunning())
    return;

  // Stop tracing only if all agents report back.
  if(--pending_clock_sync_ack_count_ == 0) {
    clock_sync_timer_.Stop();
    StopTracingAfterClockSync();
  }
}

void TracingControllerImpl::RequestGlobalMemoryDump(
    const base::trace_event::MemoryDumpRequestArgs& args,
    const base::trace_event::MemoryDumpCallback& callback) {
  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(
        BrowserThread::UI, FROM_HERE,
        base::Bind(&TracingControllerImpl::RequestGlobalMemoryDump,
                   base::Unretained(this), args, callback));
    return;
  }
  // Abort if another dump is already in progress.
  if (pending_memory_dump_guid_) {
    DVLOG(1) << "Requested memory dump " << args.dump_guid
             << " while waiting for " << pending_memory_dump_guid_;
    if (!callback.is_null())
      callback.Run(args.dump_guid, false /* success */);
    return;
  }

  // Count myself (local trace) in pending_memory_dump_ack_count_, acked by
  // OnBrowserProcessMemoryDumpDone().
  pending_memory_dump_ack_count_ = trace_message_filters_.size() + 1;
  pending_memory_dump_filters_.clear();
  pending_memory_dump_guid_ = args.dump_guid;
  pending_memory_dump_callback_ = callback;
  failed_memory_dump_count_ = 0;

  MemoryDumpManagerDelegate::CreateProcessDump(
      args, base::Bind(&TracingControllerImpl::OnBrowserProcessMemoryDumpDone,
                       base::Unretained(this)));

  // If there are no child processes we are just done.
  if (pending_memory_dump_ack_count_ == 1)
    return;

  pending_memory_dump_filters_ = trace_message_filters_;

  for (const scoped_refptr<TraceMessageFilter>& tmf : trace_message_filters_)
    tmf->SendProcessMemoryDumpRequest(args);
}

uint64_t TracingControllerImpl::GetTracingProcessId() const {
  return ChildProcessHost::kBrowserTracingProcessId;
}

void TracingControllerImpl::AddTraceMessageFilterObserver(
    TraceMessageFilterObserver* observer) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  trace_message_filter_observers_.AddObserver(observer);

  for (auto& filter : trace_message_filters_)
    observer->OnTraceMessageFilterAdded(filter.get());
}

void TracingControllerImpl::RemoveTraceMessageFilterObserver(
    TraceMessageFilterObserver* observer) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  trace_message_filter_observers_.RemoveObserver(observer);

  for (auto& filter : trace_message_filters_)
    observer->OnTraceMessageFilterRemoved(filter.get());
}

void TracingControllerImpl::OnProcessMemoryDumpResponse(
    TraceMessageFilter* trace_message_filter,
    uint64_t dump_guid,
    bool success) {
  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(
        BrowserThread::UI, FROM_HERE,
        base::Bind(&TracingControllerImpl::OnProcessMemoryDumpResponse,
                   base::Unretained(this),
                   make_scoped_refptr(trace_message_filter), dump_guid,
                   success));
    return;
  }

  TraceMessageFilterSet::iterator it =
      pending_memory_dump_filters_.find(trace_message_filter);

  if (pending_memory_dump_guid_ != dump_guid ||
      it == pending_memory_dump_filters_.end()) {
    DLOG(WARNING) << "Received unexpected memory dump response: " << dump_guid;
    return;
  }

  DCHECK_GT(pending_memory_dump_ack_count_, 0);
  --pending_memory_dump_ack_count_;
  pending_memory_dump_filters_.erase(it);
  if (!success) {
    ++failed_memory_dump_count_;
    DLOG(WARNING) << "Global memory dump failed because of NACK from child "
                  << trace_message_filter->peer_pid();
  }
  FinalizeGlobalMemoryDumpIfAllProcessesReplied();
}

void TracingControllerImpl::OnBrowserProcessMemoryDumpDone(uint64_t dump_guid,
                                                           bool success) {
  DCHECK_GT(pending_memory_dump_ack_count_, 0);
  --pending_memory_dump_ack_count_;
  if (!success) {
    ++failed_memory_dump_count_;
    DLOG(WARNING) << "Global memory dump aborted on the current process";
  }
  FinalizeGlobalMemoryDumpIfAllProcessesReplied();
}

void TracingControllerImpl::FinalizeGlobalMemoryDumpIfAllProcessesReplied() {
  if (pending_memory_dump_ack_count_ > 0)
    return;

  DCHECK_NE(0u, pending_memory_dump_guid_);
  const bool global_success = failed_memory_dump_count_ == 0;
  if (!pending_memory_dump_callback_.is_null()) {
    pending_memory_dump_callback_.Run(pending_memory_dump_guid_,
                                      global_success);
    pending_memory_dump_callback_.Reset();
  }
  pending_memory_dump_guid_ = 0;
}

void TracingControllerImpl::OnMonitoringStateChanged(bool is_monitoring) {
  if (is_monitoring_ == is_monitoring)
    return;

  is_monitoring_ = is_monitoring;
#if !defined(OS_ANDROID)
  for (std::set<TracingUI*>::iterator it = tracing_uis_.begin();
       it != tracing_uis_.end(); it++) {
    (*it)->OnMonitoringStateChanged(is_monitoring);
  }
#endif
}

}  // namespace content