Histograms - Support histograms for Plugins, GPU

chrome/browser/metrics/histogram_synchronizer.cc

Index: chrome/browser/metrics/histogram_synchronizer.cc
===================================================================
--- chrome/browser/metrics/histogram_synchronizer.cc	(revision 146279)
+++ chrome/browser/metrics/histogram_synchronizer.cc	(working copy)
@@ -1,264 +0,0 @@
-// 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/histogram_synchronizer.h"
-
-#include "base/bind.h"
-#include "base/logging.h"
-#include "base/metrics/histogram.h"
-#include "base/threading/thread.h"
-#include "base/threading/thread_restrictions.h"
-#include "chrome/common/chrome_constants.h"
-#include "chrome/common/render_messages.h"
-#include "content/public/browser/browser_thread.h"
-#include "content/public/browser/render_process_host.h"
-
-using base::Time;
-using base::TimeDelta;
-using base::TimeTicks;
-using content::BrowserThread;
-
-// 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.
-static const int kNeverUsableSequenceNumber = -2;
-
-HistogramSynchronizer::HistogramSynchronizer()
-  : lock_(),
-    received_all_renderer_histograms_(&lock_),
-    callback_thread_(NULL),
-    last_used_sequence_number_(kNeverUsableSequenceNumber),
-    async_sequence_number_(kNeverUsableSequenceNumber),
-    async_renderers_pending_(0),
-    synchronous_sequence_number_(kNeverUsableSequenceNumber),
-    synchronous_renderers_pending_(0) {
-  DCHECK(histogram_synchronizer_ == NULL);
-  histogram_synchronizer_ = this;
-}
-
-HistogramSynchronizer::~HistogramSynchronizer() {
-  // Just in case we have any pending tasks, clear them out.
-  SetCallbackTaskAndThread(NULL, base::Closure());
-  histogram_synchronizer_ = NULL;
-}
-
-// static
-HistogramSynchronizer* HistogramSynchronizer::CurrentSynchronizer() {
-  DCHECK(histogram_synchronizer_ != NULL);
-  return histogram_synchronizer_;
-}
-
-void HistogramSynchronizer::FetchRendererHistogramsSynchronously(
-    TimeDelta wait_time) {
-  NotifyAllRenderers(SYNCHRONOUS_HISTOGRAMS);
-
-  TimeTicks start = TimeTicks::Now();
-  TimeTicks end_time = start + wait_time;
-  int unresponsive_renderer_count;
-  {
-    base::AutoLock auto_lock(lock_);
-    while (synchronous_renderers_pending_ > 0 && TimeTicks::Now() < end_time) {
-      wait_time = end_time - TimeTicks::Now();
-      base::ThreadRestrictions::ScopedAllowWait allow_wait;
-      received_all_renderer_histograms_.TimedWait(wait_time);
-    }
-    unresponsive_renderer_count = synchronous_renderers_pending_;
-    synchronous_renderers_pending_ = 0;
-    synchronous_sequence_number_ = kNeverUsableSequenceNumber;
-  }
-  UMA_HISTOGRAM_COUNTS("Histogram.RendersNotRespondingSynchronous",
-                       unresponsive_renderer_count);
-  if (!unresponsive_renderer_count)
-    UMA_HISTOGRAM_TIMES("Histogram.FetchRendererHistogramsSynchronously",
-                        TimeTicks::Now() - start);
-}
-
-// static
-void HistogramSynchronizer::FetchRendererHistogramsAsynchronously(
-    MessageLoop* callback_thread,
-    const base::Closure& callback,
-    base::TimeDelta wait_time) {
-  DCHECK(callback_thread != NULL);
-  DCHECK(!callback.is_null());
-
-  HistogramSynchronizer* current_synchronizer = CurrentSynchronizer();
-
-  if (current_synchronizer == NULL) {
-    // System teardown is happening.
-    callback_thread->PostTask(FROM_HERE, callback);
-    return;
-  }
-
-  current_synchronizer->SetCallbackTaskAndThread(callback_thread,
-                                                 callback);
-
-  int sequence_number =
-      current_synchronizer->NotifyAllRenderers(ASYNC_HISTOGRAMS);
-
-  // Post a task that would be called after waiting for wait_time.  This acts
-  // as a watchdog, to ensure that a non-responsive renderer won't block us from
-  // making the callback.
-  BrowserThread::PostDelayedTask(
-      BrowserThread::UI, FROM_HERE,
-      base::Bind(
-          &HistogramSynchronizer::ForceHistogramSynchronizationDoneCallback,
-          current_synchronizer,
-          sequence_number),
-      wait_time);
-}
-
-// static
-void HistogramSynchronizer::DeserializeHistogramList(
-    int sequence_number,
-    const std::vector<std::string>& histograms) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  for (std::vector<std::string>::const_iterator it = histograms.begin();
-       it < histograms.end();
-       ++it) {
-    base::Histogram::DeserializeHistogramInfo(*it);
-  }
-
-  HistogramSynchronizer* current_synchronizer = CurrentSynchronizer();
-  if (current_synchronizer == NULL)
-    return;
-
-  // Record that we have received a histogram from renderer process.
-  current_synchronizer->DecrementPendingRenderers(sequence_number);
-}
-
-int HistogramSynchronizer::NotifyAllRenderers(
-    RendererHistogramRequester requester) {
-  // To iterate over RenderProcessHosts, or to send messages to the hosts, we
-  // need to be on the UI thread.
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-  int notification_count = 0;
-  for (content::RenderProcessHost::iterator it(
-          content::RenderProcessHost::AllHostsIterator());
-       !it.IsAtEnd(); it.Advance())
-     ++notification_count;
-
-  int sequence_number = GetNextAvailableSequenceNumber(requester,
-                                                       notification_count);
-  for (content::RenderProcessHost::iterator it(
-          content::RenderProcessHost::AllHostsIterator());
-       !it.IsAtEnd(); it.Advance()) {
-    if (!it.GetCurrentValue()->Send(
-        new ChromeViewMsg_GetRendererHistograms(sequence_number)))
-      DecrementPendingRenderers(sequence_number);
-  }
-
-  return sequence_number;
-}
-
-void HistogramSynchronizer::DecrementPendingRenderers(int sequence_number) {
-  bool synchronous_completed = false;
-  bool asynchronous_completed = false;
-
-  {
-    base::AutoLock auto_lock(lock_);
-    if (sequence_number == async_sequence_number_) {
-      if (--async_renderers_pending_ <= 0)
-        asynchronous_completed = true;
-    } else if (sequence_number == synchronous_sequence_number_) {
-      if (--synchronous_renderers_pending_ <= 0)
-        synchronous_completed = true;
-    }
-  }
-
-  if (asynchronous_completed)
-    ForceHistogramSynchronizationDoneCallback(sequence_number);
-  else if (synchronous_completed)
-    received_all_renderer_histograms_.Signal();
-}
-
-void HistogramSynchronizer::SetCallbackTaskAndThread(
-    MessageLoop* callback_thread,
-    const base::Closure& callback) {
-  base::Closure old_callback;
-  MessageLoop* old_thread = NULL;
-  TimeTicks old_start_time;
-  int unresponsive_renderers;
-  const TimeTicks now = TimeTicks::Now();
-  {
-    base::AutoLock auto_lock(lock_);
-    old_callback = callback_;
-    callback_ = callback;
-    old_thread = callback_thread_;
-    callback_thread_ = callback_thread;
-    unresponsive_renderers = async_renderers_pending_;
-    old_start_time = async_callback_start_time_;
-    async_callback_start_time_ = now;
-    // Prevent premature calling of our new callbacks.
-    async_sequence_number_ = kNeverUsableSequenceNumber;
-  }
-  // Just in case there was a task pending....
-  InternalPostTask(old_thread, old_callback, unresponsive_renderers,
-                   old_start_time);
-}
-
-void HistogramSynchronizer::ForceHistogramSynchronizationDoneCallback(
-    int sequence_number) {
-  base::Closure callback;
-  MessageLoop* thread = NULL;
-  TimeTicks started;
-  int unresponsive_renderers;
-  {
-    base::AutoLock lock(lock_);
-    if (sequence_number != async_sequence_number_)
-      return;
-    callback = callback_;
-    thread = callback_thread_;
-    callback_.Reset();
-    callback_thread_ = NULL;
-    started = async_callback_start_time_;
-    unresponsive_renderers = async_renderers_pending_;
-  }
-  InternalPostTask(thread, callback, unresponsive_renderers, started);
-}
-
-void HistogramSynchronizer::InternalPostTask(MessageLoop* thread,
-                                             const base::Closure& callback,
-                                             int unresponsive_renderers,
-                                             const base::TimeTicks& started) {
-  if (callback.is_null() || !thread)
-    return;
-  UMA_HISTOGRAM_COUNTS("Histogram.RendersNotRespondingAsynchronous",
-                       unresponsive_renderers);
-  if (!unresponsive_renderers) {
-    UMA_HISTOGRAM_TIMES("Histogram.FetchRendererHistogramsAsynchronously",
-                        TimeTicks::Now() - started);
-  }
-
-  thread->PostTask(FROM_HERE, callback);
-}
-
-int HistogramSynchronizer::GetNextAvailableSequenceNumber(
-    RendererHistogramRequester requester,
-    int renderer_count) {
-  base::AutoLock auto_lock(lock_);
-  ++last_used_sequence_number_;
-  // Watch out for wrapping to a negative number.
-  if (last_used_sequence_number_ < 0) {
-    // Bypass the reserved number, which is used when a renderer spontaneously
-    // decides to send some histogram data.
-    last_used_sequence_number_ =
-        chrome::kHistogramSynchronizerReservedSequenceNumber + 1;
-  }
-  DCHECK_NE(last_used_sequence_number_,
-            chrome::kHistogramSynchronizerReservedSequenceNumber);
-  if (requester == ASYNC_HISTOGRAMS) {
-    async_sequence_number_ = last_used_sequence_number_;
-    async_renderers_pending_ = renderer_count;
-  } else if (requester == SYNCHRONOUS_HISTOGRAMS) {
-    synchronous_sequence_number_ = last_used_sequence_number_;
-    synchronous_renderers_pending_ = renderer_count;
-  }
-  return last_used_sequence_number_;
-}
-
-// static
-HistogramSynchronizer* HistogramSynchronizer::histogram_synchronizer_ = NULL;