Add ProcessPowerCollector to audit power information.

chrome/browser/power/process_power_collector.cc

Index: chrome/browser/power/process_power_collector.cc
diff --git a/chrome/browser/power/process_power_collector.cc b/chrome/browser/power/process_power_collector.cc
new file mode 100644
index 0000000000000000000000000000000000000000..7f56798eded56f63dcd64e36ac28b11a29a43064
--- /dev/null
+++ b/chrome/browser/power/process_power_collector.cc
@@ -0,0 +1,177 @@
+// Copyright 2014 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/power/process_power_collector.h"
+
+#include "apps/app_window.h"
+#include "apps/app_window_registry.h"
+#include "base/process/process_handle.h"
+#include "base/process/process_metrics.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/profiles/profile_manager.h"
+#include "chrome/browser/ui/tab_contents/tab_contents_iterator.h"
+#include "components/power/origin_power_map.h"
+#include "components/power/origin_power_map_factory.h"
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/web_contents.h"
+#include "url/gurl.h"
+
+#if defined(OS_CHROMEOS)
+#include "chrome/browser/chromeos/power/power_data_collector.h"
+#endif
+
+namespace {
+const int kSecondsPerSample = 30;
+}
+
+ProcessPowerCollector::PerProcessData::PerProcessData(
+    base::ProcessMetrics* metrics,
+    const GURL& origin,
+    Profile* profile)
+    : metrics_(metrics),
+      profile_(profile),
+      last_origin_(origin),
+      last_cpu_percent_(0) {
+}
+
+ProcessPowerCollector::PerProcessData::PerProcessData() {
+}
+
+ProcessPowerCollector::PerProcessData::~PerProcessData() {
+}
+
+void ProcessPowerCollector::PerProcessData::SetLastCpuPercent(int new_cpu) {
+  last_cpu_percent_ = new_cpu;
+}
+
+ProcessPowerCollector::ProcessPowerCollector() {
+}
+
+ProcessPowerCollector::~ProcessPowerCollector() {
+}
+
+void ProcessPowerCollector::StartUpdating() {
+  DCHECK(!timer_.IsRunning());
+  timer_.Start(FROM_HERE,
+               base::TimeDelta::FromSeconds(kSecondsPerSample),
+               this,
+               &ProcessPowerCollector::UpdatePowerConsumptionCallback);
+}
+
+void ProcessPowerCollector::UpdatePowerConsumptionCallback() {
+  UpdateMetricsMap();
+  RecordCpuUsageByOrigin(PopulateCpuUsageByOrigin());
+}
+
+void ProcessPowerCollector::UpdateMetricsMap() {
+  // Update all tabs.
+  for (TabContentsIterator it; !it.done(); it.Next()) {
+    content::RenderProcessHost* render_process = it->GetRenderProcessHost();
+    // Skip incognito web contents.
+    if (render_process->GetBrowserContext()->IsOffTheRecord())
+      continue;
+    AddProcessToMap(render_process, it->GetLastCommittedURL().GetOrigin());
+  }
+
+  // Iterate over all profiles to find all app windows to attribute all apps.
+  ProfileManager* pm = g_browser_process->profile_manager();
+  std::vector<Profile*> open_profiles = pm->GetLoadedProfiles();
+  for (std::vector<Profile*>::const_iterator it = open_profiles.begin();
+       it != open_profiles.end();
+       ++it) {
+    const apps::AppWindowRegistry::AppWindowList& app_windows =
+        apps::AppWindowRegistry::Get(*it)->app_windows();
+    for (apps::AppWindowRegistry::AppWindowList::const_iterator itr =
+             app_windows.begin();
+         itr != app_windows.end();
+         ++itr) {
+      content::WebContents* web_contents = (*itr)->web_contents();
+
+      AddProcessToMap(web_contents->GetRenderProcessHost(),
+                      web_contents->GetLastCommittedURL().GetOrigin());
+    }
+  }
+}
+
+double ProcessPowerCollector::PopulateCpuUsageByOrigin() {
+  ProcessMetricsMap::iterator it = metrics_map_.begin();
+  double cpu_cycle = 0.0;
+  while (it != metrics_map_.end()) {
+    // If the process doesn't exist anymore, remove it.
+    if (it->second->last_cpu_used() < 0) {

[Daniel Erat, 2014/08/20 00:10:42]

should you be doing this after you update the last percent instead of before it?
(i admit that this is in conflict with the next comment; perhaps i'm voting for
the previous method and this method to be merged)

[Daniel Nishi, 2014/08/20 17:16:46]

We remove before we query the last percent to avoid needless queries of
processes that no longer exist.

I've merged this into what was UpdateMetricsMap() and is now
SynchronizeProcesses() to move the adding and removing into the same method.

+      metrics_map_.erase(it++);

[Daniel Erat, 2014/08/20 00:10:42]

how about moving the stale-process-clearing to the method that's currently named
UpdateMetricsMap()? it feels strange to add processes in one method but delete
them somewhere else instead of having a single method that ensure the map holds
the correct entries.

+      continue;
+    }
+    it->second->SetLastCpuPercent(it->second->metrics()->GetCPUUsage());
+
+    // Skip errors.
+    if (it->second->last_cpu_used() < 0) {

[Daniel Erat, 2014/08/20 00:10:42]

hmm, so you skip negative usages here. this seems weird; won't you just erase
the process the next time around?

is this code all depending on undocumented (i think) behavior where
ProcessMonitor returns -1 if the process has gone away? if so, please find a
safer way to detect this case.

[Daniel Nishi, 2014/08/20 17:16:46]

Good catch. The intent was to just skip, since the process was still around, but
the undocumented removal behavior would kick in during the second loop.

I've added a boolean of |seen_this_cycle| to make this process better
documented.

+      it++;
+      continue;
+    }
+
+    cpu_cycle += it->second->last_cpu_used();
+    it++;
+  }
+
+  return cpu_cycle;
+}
+
+void ProcessPowerCollector::RecordCpuUsageByOrigin(double cpu_cycle) {
+#if defined(OS_CHROMEOS)
+  // Don't record data yet if no power data exists yet.
+  chromeos::PowerDataCollector* power_data_collector =
+      chromeos::PowerDataCollector::Get();
+  if (power_data_collector->power_supply_data().empty())
+    return;
+
+  chromeos::PowerDataCollector::PowerSupplySample sample =
+      power_data_collector->power_supply_data().back();
+
+  // Don't record data if plugged in.
+  if (sample.external_power)
+    return;
+#endif
+
+  for (ProcessMetricsMap::iterator it = metrics_map_.begin();
+       it != metrics_map_.end();
+       ++it) {
+    double last_process_power_usage = it->second->last_cpu_used();
+#if defined(OS_CHROMEOS)
+    // Only query discharge rate if there is a battery.
+    if (sample.battery_percent > -1 && cpu_cycle > 0)
+      last_process_power_usage =
+          last_process_power_usage * sample.battery_discharge_rate / cpu_cycle;
+#endif
+
+    GURL origin = it->second->last_origin();
+    power::OriginPowerMap* origin_power_map =
+        power::OriginPowerMapFactory::GetForBrowserContext(
+            it->second->profile());
+    DCHECK(origin_power_map);
+    origin_power_map->AddPowerForOrigin(origin, last_process_power_usage);
+
+    // Invalidate |last_cpu| for the next cycle.
+    it->second->SetLastCpuPercent(-1);
+  }
+}
+
+void ProcessPowerCollector::AddProcessToMap(
+    const content::RenderProcessHost* rph,
+    const GURL& origin) {
+  base::ProcessHandle handle = rph->GetHandle();
+  if (metrics_map_.find(handle) == metrics_map_.end()) {
+    metrics_map_[handle] = linked_ptr<PerProcessData>(new PerProcessData(
+#if defined(OS_MACOSX)
+        base::ProcessMetrics::CreateProcessMetrics(handle, NULL),
+#else
+        base::ProcessMetrics::CreateProcessMetrics(handle),
+#endif
+        origin,
+        Profile::FromBrowserContext(rph->GetBrowserContext())));
+  }
+  // Reset the CPU usage to 0 to signify that the process still exists.
+  metrics_map_[handle]->SetLastCpuPercent(0);
+}