Moves ProfilerMetricsProvider to //components/metrics.

chrome/browser/metrics/tracking_synchronizer.cc

-// Copyright (c) 2012 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 "chrome/browser/metrics/tracking_synchronizer.h"
-
-#include "base/bind.h"
-#include "base/metrics/histogram.h"
-#include "base/threading/thread.h"
-#include "base/tracked_objects.h"
-#include "chrome/browser/metrics/tracking_synchronizer_observer.h"
-#include "content/public/browser/browser_thread.h"
-#include "content/public/browser/profiler_controller.h"
-#include "content/public/common/process_type.h"
-
-using base::TimeTicks;
-using content::BrowserThread;
-
-namespace {
-
-// Negative numbers are never used as sequence numbers.  We explicitly pick a
-// negative number that is "so negative" that even when we add one (as is done
-// when we generated the next sequence number) that it will still be negative.
-// We have code that handles wrapping around on an overflow into negative
-// territory.
-const int kNeverUsableSequenceNumber = -2;
-
-// This singleton instance should be started during the single threaded
-// portion of main(). It initializes globals to provide support for all future
-// calls. This object is created on the UI thread, and it is destroyed after
-// all the other threads have gone away. As a result, it is ok to call it
-// from the UI thread, or for about:profiler.
-static chrome_browser_metrics::TrackingSynchronizer* g_tracking_synchronizer =
-    NULL;
-
-}  // anonymous namespace
-
-namespace chrome_browser_metrics {
-
-// The "RequestContext" structure describes an individual request received
-// from the UI. All methods are accessible on UI thread.
-class TrackingSynchronizer::RequestContext {
- public:
-  // A map from sequence_number_ to the actual RequestContexts.
-  typedef std::map<int, RequestContext*> RequestContextMap;
-
-  RequestContext(
-      const base::WeakPtr<TrackingSynchronizerObserver>& callback_object,
-      int sequence_number)
-      : callback_object_(callback_object),
-        sequence_number_(sequence_number),
-        received_process_group_count_(0),
-        processes_pending_(0) {
-  }
-  ~RequestContext() {}
-
-  void SetReceivedProcessGroupCount(bool done) {
-    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-    received_process_group_count_ = done;
-  }
-
-  // Methods for book keeping of processes_pending_.
-  void IncrementProcessesPending() {
-    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-    ++processes_pending_;
-  }
-
-  void AddProcessesPending(int processes_pending) {
-    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-    processes_pending_ += processes_pending;
-  }
-
-  void DecrementProcessesPending() {
-    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-    --processes_pending_;
-  }
-
-  // Records that we are waiting for one less tracking data from a process for
-  // the given sequence number. If |received_process_group_count_| and
-  // |processes_pending_| are zero, then delete the current object by calling
-  // Unregister.
-  void DeleteIfAllDone() {
-    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-    if (processes_pending_ <= 0 && received_process_group_count_)
-      RequestContext::Unregister(sequence_number_);
-  }
-
-  // Register |callback_object| in |outstanding_requests_| map for the given
-  // |sequence_number|.
-  static RequestContext* Register(
-      int sequence_number,
-      const base::WeakPtr<TrackingSynchronizerObserver>& callback_object) {
-    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-    RequestContext* request = new RequestContext(
-        callback_object, sequence_number);
-    outstanding_requests_.Get()[sequence_number] = request;
-
-    return request;
-  }
-
-  // Find the |RequestContext| in |outstanding_requests_| map for the given
-  // |sequence_number|.
-  static RequestContext* GetRequestContext(int sequence_number) {
-    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-    RequestContextMap::iterator it =
-        outstanding_requests_.Get().find(sequence_number);
-    if (it == outstanding_requests_.Get().end())
-      return NULL;
-
-    RequestContext* request = it->second;
-    DCHECK_EQ(sequence_number, request->sequence_number_);
-    return request;
-  }
-
-  // Delete the entry for the given |sequence_number| from
-  // |outstanding_requests_| map. This method is called when all changes have
-  // been acquired, or when the wait time expires (whichever is sooner).
-  static void Unregister(int sequence_number) {
-    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-    RequestContextMap::iterator it =
-        outstanding_requests_.Get().find(sequence_number);
-    if (it == outstanding_requests_.Get().end())
-      return;
-
-    RequestContext* request = it->second;
-    DCHECK_EQ(sequence_number, request->sequence_number_);
-    bool received_process_group_count = request->received_process_group_count_;
-    int unresponsive_processes = request->processes_pending_;
-
-    if (request->callback_object_.get())
-      request->callback_object_->FinishedReceivingProfilerData();
-
-    delete request;
-    outstanding_requests_.Get().erase(it);
-
-    UMA_HISTOGRAM_BOOLEAN("Profiling.ReceivedProcessGroupCount",
-                          received_process_group_count);
-    UMA_HISTOGRAM_COUNTS("Profiling.PendingProcessNotResponding",
-                         unresponsive_processes);
-  }
-
-  // Delete all the entries in |outstanding_requests_| map.
-  static void OnShutdown() {
-    // Just in case we have any pending tasks, clear them out.
-    while (!outstanding_requests_.Get().empty()) {
-      RequestContextMap::iterator it = outstanding_requests_.Get().begin();
-      delete it->second;
-      outstanding_requests_.Get().erase(it);
-    }
-  }
-
-  // Requests are made to asynchronously send data to the |callback_object_|.
-  base::WeakPtr<TrackingSynchronizerObserver> callback_object_;
-
-  // The sequence number used by the most recent update request to contact all
-  // processes.
-  int sequence_number_;
-
-  // Indicates if we have received all pending processes count.
-  bool received_process_group_count_;
-
-  // The number of pending processes (browser, all renderer processes and
-  // browser child processes) that have not yet responded to requests.
-  int processes_pending_;
-
-  // Map of all outstanding RequestContexts, from sequence_number_ to
-  // RequestContext.
-  static base::LazyInstance<RequestContextMap>::Leaky outstanding_requests_;
-};
-
-// static
-base::LazyInstance
-    <TrackingSynchronizer::RequestContext::RequestContextMap>::Leaky
-        TrackingSynchronizer::RequestContext::outstanding_requests_ =
-            LAZY_INSTANCE_INITIALIZER;
-
-// TrackingSynchronizer methods and members.
-
-TrackingSynchronizer::TrackingSynchronizer()
-    : last_used_sequence_number_(kNeverUsableSequenceNumber) {
-  DCHECK(!g_tracking_synchronizer);
-  g_tracking_synchronizer = this;
-  content::ProfilerController::GetInstance()->Register(this);
-}
-
-TrackingSynchronizer::~TrackingSynchronizer() {
-  content::ProfilerController::GetInstance()->Unregister(this);
-
-  // Just in case we have any pending tasks, clear them out.
-  RequestContext::OnShutdown();
-
-  g_tracking_synchronizer = NULL;
-}
-
-// static
-void TrackingSynchronizer::FetchProfilerDataAsynchronously(
-    const base::WeakPtr<TrackingSynchronizerObserver>& callback_object) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-  if (!g_tracking_synchronizer) {
-    // System teardown is happening.
-    return;
-  }
-
-  int sequence_number = g_tracking_synchronizer->RegisterAndNotifyAllProcesses(
-      callback_object);
-
-  // Post a task that would be called after waiting for wait_time.  This acts
-  // as a watchdog, to cancel the requests for non-responsive processes.
-  BrowserThread::PostDelayedTask(
-      BrowserThread::UI, FROM_HERE,
-      base::Bind(&RequestContext::Unregister, sequence_number),
-      base::TimeDelta::FromMinutes(1));
-}
-
-void TrackingSynchronizer::OnPendingProcesses(int sequence_number,
-                                              int pending_processes,
-                                              bool end) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-  RequestContext* request = RequestContext::GetRequestContext(sequence_number);
-  if (!request)
-    return;
-  request->AddProcessesPending(pending_processes);
-  request->SetReceivedProcessGroupCount(end);
-  request->DeleteIfAllDone();
-}
-
-void TrackingSynchronizer::OnProfilerDataCollected(
-    int sequence_number,
-    const tracked_objects::ProcessDataSnapshot& profiler_data,
-    int process_type) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  DecrementPendingProcessesAndSendData(sequence_number, profiler_data,
-                                       process_type);
-}
-
-int TrackingSynchronizer::RegisterAndNotifyAllProcesses(
-    const base::WeakPtr<TrackingSynchronizerObserver>& callback_object) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-  int sequence_number = GetNextAvailableSequenceNumber();
-
-  RequestContext* request =
-      RequestContext::Register(sequence_number, callback_object);
-
-  // Increment pending process count for sending browser's profiler data.
-  request->IncrementProcessesPending();
-
-  // Get profiler data from renderer and browser child processes.
-  content::ProfilerController::GetInstance()->GetProfilerData(sequence_number);
-
-  // Send profiler_data from browser process.
-  tracked_objects::ProcessDataSnapshot process_data;
-  tracked_objects::ThreadData::Snapshot(false, &process_data);
-  DecrementPendingProcessesAndSendData(sequence_number, process_data,
-                                       content::PROCESS_TYPE_BROWSER);
-
-  return sequence_number;
-}
-
-void TrackingSynchronizer::DecrementPendingProcessesAndSendData(
-    int sequence_number,
-    const tracked_objects::ProcessDataSnapshot& profiler_data,
-    int process_type) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-  RequestContext* request = RequestContext::GetRequestContext(sequence_number);
-  if (!request)
-    return;
-
-  if (request->callback_object_.get()) {
-    request->callback_object_
-        ->ReceivedProfilerData(profiler_data, process_type);
-  }
-
-  // Delete request if we have heard back from all child processes.
-  request->DecrementProcessesPending();
-  request->DeleteIfAllDone();
-}
-
-int TrackingSynchronizer::GetNextAvailableSequenceNumber() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-  ++last_used_sequence_number_;
-
-  // Watch out for wrapping to a negative number.
-  if (last_used_sequence_number_ < 0)
-    last_used_sequence_number_ = 1;
-  return last_used_sequence_number_;
-}
-
-}  // namespace chrome_browser_metrics