Histograms - Support histograms for Plugins, GPU

content/browser/histogram_controller.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 "content/browser/histogram_controller.h"
+
+#include "base/bind.h"
+#include "base/metrics/histogram.h"
+#include "content/browser/histogram_subscriber.h"
+#include "content/common/child_process_messages.h"
+#include "content/public/browser/browser_child_process_host_iterator.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/child_process_data.h"
+#include "content/public/browser/render_process_host.h"
+
+using content::BrowserChildProcessHostIterator;

[jam, 2012/06/07 03:34:33]

you don't need using statements since this class is in the content namespace

[ramant (doing other things), 2012/06/07 23:39:25]

Done.

+using content::BrowserThread;
+
+namespace content {
+
+HistogramController* HistogramController::GetInstance() {
+  return Singleton<HistogramController>::get();
+}
+
+HistogramController::HistogramController() : subscriber_(NULL) {
+}
+
+HistogramController::~HistogramController() {
+}
+
+void HistogramController::OnPendingProcesses(int sequence_number,
+                                             int pending_processes,
+                                             bool end) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  if (subscriber_)
+    subscriber_->OnPendingProcesses(sequence_number, pending_processes, end);
+}
+
+void HistogramController::OnHistogramDataCollected(
+    int sequence_number,
+    const std::vector<std::string>& pickled_histograms) {
+  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(&HistogramController::OnHistogramDataCollected,
+                   base::Unretained(this),
+                   sequence_number,
+                   pickled_histograms));
+    return;
+  }
+
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  if (subscriber_) {
+    subscriber_->OnHistogramDataCollected(sequence_number,
+                                          pickled_histograms);
+  }
+}
+
+void HistogramController::Register(HistogramSubscriber* subscriber) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(!subscriber_);
+  subscriber_ = subscriber;
+}
+
+void HistogramController::Unregister(
+    const HistogramSubscriber* subscriber) {
+  DCHECK_EQ(subscriber_, subscriber);
+  subscriber_ = NULL;
+}
+
+void HistogramController::GetHistogramDataFromChildProcesses(
+    int sequence_number) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  int pending_processes = 0;
+  for (BrowserChildProcessHostIterator iter; !iter.Done(); ++iter) {
+    ++pending_processes;
+    if (!iter.Send(new ChildProcessMsg_GetChildHistogramData(sequence_number)))
+      --pending_processes;
+  }
+
+  BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(
+          &HistogramController::OnPendingProcesses,
+          base::Unretained(this),
+          sequence_number,
+          pending_processes,
+          true));
+}
+
+void HistogramController::GetHistogramData(int sequence_number) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  int pending_processes = 0;
+  for (RenderProcessHost::iterator it(RenderProcessHost::AllHostsIterator());
+       !it.IsAtEnd(); it.Advance()) {
+    ++pending_processes;
+    if (!it.GetCurrentValue()->Send(
+            new ChildProcessMsg_GetChildHistogramData(sequence_number))) {
+      --pending_processes;
+    }
+  }
+  OnPendingProcesses(sequence_number, pending_processes, false);
+
+  BrowserThread::PostTask(
+      BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&HistogramController::GetHistogramDataFromChildProcesses,
+                 base::Unretained(this),
+                 sequence_number));
+}
+
+}  // namespace content