Add m-esr52 at 52.6.0

1 files changed, 2045 insertions, 0 deletions

diff --git a/hal/gonk/GonkHal.cpp b/hal/gonk/GonkHal.cpp
new file mode 100644
index 0000000000..05d9295a22
--- /dev/null
+++ b/hal/gonk/GonkHal.cpp
@@ -0,0 +1,2045 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* Copyright 2012 Mozilla Foundation and Mozilla contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/android_alarm.h>
+#include <math.h>
+#include <regex.h>
+#include <sched.h>
+#include <stdio.h>
+#include <sys/klog.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/resource.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "mozilla/DebugOnly.h"
+
+#include "android/log.h"
+#include "cutils/properties.h"
+#include "hardware/hardware.h"
+#include "hardware/lights.h"
+#include "hardware_legacy/uevent.h"
+#include "hardware_legacy/vibrator.h"
+#include "hardware_legacy/power.h"
+#include "libdisplay/GonkDisplay.h"
+#include "utils/threads.h"
+
+#include "base/message_loop.h"
+#include "base/task.h"
+
+#include "Hal.h"
+#include "HalImpl.h"
+#include "HalLog.h"
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/dom/battery/Constants.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/FileUtils.h"
+#include "mozilla/Monitor.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/Services.h"
+#include "mozilla/StaticMutex.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/UniquePtrExtensions.h"
+#include "nsAlgorithm.h"
+#include "nsPrintfCString.h"
+#include "nsIObserver.h"
+#include "nsIObserverService.h"
+#include "nsIRecoveryService.h"
+#include "nsIRunnable.h"
+#include "nsScreenManagerGonk.h"
+#include "nsThreadUtils.h"
+#include "nsThreadUtils.h"
+#include "nsIThread.h"
+#include "nsXULAppAPI.h"
+#include "OrientationObserver.h"
+#include "UeventPoller.h"
+#include "nsIWritablePropertyBag2.h"
+#include <algorithm>
+
+#define NsecPerMsec  1000000LL
+#define NsecPerSec   1000000000
+
+// The header linux/oom.h is not available in bionic libc. We
+// redefine some of its constants here.
+
+#ifndef OOM_DISABLE
+#define OOM_DISABLE  (-17)
+#endif
+
+#ifndef OOM_ADJUST_MIN
+#define OOM_ADJUST_MIN  (-16)
+#endif
+
+#ifndef OOM_ADJUST_MAX
+#define OOM_ADJUST_MAX  15
+#endif
+
+#ifndef OOM_SCORE_ADJ_MIN
+#define OOM_SCORE_ADJ_MIN  (-1000)
+#endif
+
+#ifndef OOM_SCORE_ADJ_MAX
+#define OOM_SCORE_ADJ_MAX  1000
+#endif
+
+#ifndef BATTERY_CHARGING_ARGB
+#define BATTERY_CHARGING_ARGB 0x00FF0000
+#endif
+#ifndef BATTERY_FULL_ARGB
+#define BATTERY_FULL_ARGB 0x0000FF00
+#endif
+
+using namespace mozilla;
+using namespace mozilla::hal;
+using namespace mozilla::dom;
+
+namespace mozilla {
+namespace hal_impl {
+
+/**
+ * These are defined by libhardware, specifically, hardware/libhardware/include/hardware/lights.h
+ * in the gonk subsystem.
+ * If these change and are exposed to JS, make sure nsIHal.idl is updated as well.
+ */
+enum LightType {
+  eHalLightID_Backlight     = 0,
+  eHalLightID_Keyboard      = 1,
+  eHalLightID_Buttons       = 2,
+  eHalLightID_Battery       = 3,
+  eHalLightID_Notifications = 4,
+  eHalLightID_Attention     = 5,
+  eHalLightID_Bluetooth     = 6,
+  eHalLightID_Wifi          = 7,
+  eHalLightID_Count  // This should stay at the end
+};
+enum LightMode {
+  eHalLightMode_User   = 0,  // brightness is managed by user setting
+  eHalLightMode_Sensor = 1,  // brightness is managed by a light sensor
+  eHalLightMode_Count
+};
+enum FlashMode {
+  eHalLightFlash_None     = 0,
+  eHalLightFlash_Timed    = 1,  // timed flashing.  Use flashOnMS and flashOffMS for timing
+  eHalLightFlash_Hardware = 2,  // hardware assisted flashing
+  eHalLightFlash_Count
+};
+
+struct LightConfiguration {
+  LightType light;
+  LightMode mode;
+  FlashMode flash;
+  uint32_t flashOnMS;
+  uint32_t flashOffMS;
+  uint32_t color;
+};
+
+static light_device_t* sLights[eHalLightID_Count]; // will be initialized to nullptr
+
+static light_device_t*
+GetDevice(hw_module_t* module, char const* name)
+{
+  int err;
+  hw_device_t* device;
+  err = module->methods->open(module, name, &device);
+  if (err == 0) {
+    return (light_device_t*)device;
+  } else {
+    return nullptr;
+  }
+}
+
+static void
+InitLights()
+{
+  // assume that if backlight is nullptr, nothing has been set yet
+  // if this is not true, the initialization will occur everytime a light is read or set!
+  if (!sLights[eHalLightID_Backlight]) {
+    int err;
+    hw_module_t* module;
+
+    err = hw_get_module(LIGHTS_HARDWARE_MODULE_ID, (hw_module_t const**)&module);
+    if (err == 0) {
+      sLights[eHalLightID_Backlight]
+             = GetDevice(module, LIGHT_ID_BACKLIGHT);
+      sLights[eHalLightID_Keyboard]
+             = GetDevice(module, LIGHT_ID_KEYBOARD);
+      sLights[eHalLightID_Buttons]
+             = GetDevice(module, LIGHT_ID_BUTTONS);
+      sLights[eHalLightID_Battery]
+             = GetDevice(module, LIGHT_ID_BATTERY);
+      sLights[eHalLightID_Notifications]
+             = GetDevice(module, LIGHT_ID_NOTIFICATIONS);
+      sLights[eHalLightID_Attention]
+             = GetDevice(module, LIGHT_ID_ATTENTION);
+      sLights[eHalLightID_Bluetooth]
+             = GetDevice(module, LIGHT_ID_BLUETOOTH);
+      sLights[eHalLightID_Wifi]
+             = GetDevice(module, LIGHT_ID_WIFI);
+        }
+    }
+}
+
+/**
+ * The state last set for the lights until liblights supports
+ * getting the light state.
+ */
+static light_state_t sStoredLightState[eHalLightID_Count];
+
+/**
+* Set the value of a light to a particular color, with a specific flash pattern.
+* light specifices which light.  See Hal.idl for the list of constants
+* mode specifies user set or based on ambient light sensor
+* flash specifies whether or how to flash the light
+* flashOnMS and flashOffMS specify the pattern for XXX flash mode
+* color specifies the color.  If the light doesn't support color, the given color is
+* transformed into a brightness, or just an on/off if that is all the light is capable of.
+* returns true if successful and false if failed.
+*/
+static bool
+SetLight(LightType light, const LightConfiguration& aConfig)
+{
+  light_state_t state;
+
+  InitLights();
+
+  if (light < 0 || light >= eHalLightID_Count ||
+      sLights[light] == nullptr) {
+    return false;
+  }
+
+  memset(&state, 0, sizeof(light_state_t));
+  state.color = aConfig.color;
+  state.flashMode = aConfig.flash;
+  state.flashOnMS = aConfig.flashOnMS;
+  state.flashOffMS = aConfig.flashOffMS;
+  state.brightnessMode = aConfig.mode;
+
+  sLights[light]->set_light(sLights[light], &state);
+  sStoredLightState[light] = state;
+  return true;
+}
+
+/**
+* GET the value of a light returning a particular color, with a specific flash pattern.
+* returns true if successful and false if failed.
+*/
+static bool
+GetLight(LightType light, LightConfiguration* aConfig)
+{
+  light_state_t state;
+
+  if (light < 0 || light >= eHalLightID_Count ||
+      sLights[light] == nullptr) {
+    return false;
+  }
+
+  memset(&state, 0, sizeof(light_state_t));
+  state = sStoredLightState[light];
+
+  aConfig->light = light;
+  aConfig->color = state.color;
+  aConfig->flash = FlashMode(state.flashMode);
+  aConfig->flashOnMS = state.flashOnMS;
+  aConfig->flashOffMS = state.flashOffMS;
+  aConfig->mode = LightMode(state.brightnessMode);
+
+  return true;
+}
+
+namespace {
+
+/**
+ * This runnable runs for the lifetime of the program, once started.  It's
+ * responsible for "playing" vibration patterns.
+ */
+class VibratorRunnable final
+  : public nsIRunnable
+  , public nsIObserver
+{
+public:
+  VibratorRunnable()
+    : mMonitor("VibratorRunnable")
+    , mIndex(0)
+  {
+    nsCOMPtr<nsIObserverService> os = services::GetObserverService();
+    if (!os) {
+      NS_WARNING("Could not get observer service!");
+      return;
+    }
+
+    os->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false);
+  }
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIRUNNABLE
+  NS_DECL_NSIOBSERVER
+
+  // Run on the main thread, not the vibrator thread.
+  void Vibrate(const nsTArray<uint32_t> &pattern);
+  void CancelVibrate();
+
+  static bool ShuttingDown() { return sShuttingDown; }
+
+protected:
+  ~VibratorRunnable() {}
+
+private:
+  Monitor mMonitor;
+
+  // The currently-playing pattern.
+  nsTArray<uint32_t> mPattern;
+
+  // The index we're at in the currently-playing pattern.  If mIndex >=
+  // mPattern.Length(), then we're not currently playing anything.
+  uint32_t mIndex;
+
+  // Set to true in our shutdown observer.  When this is true, we kill the
+  // vibrator thread.
+  static bool sShuttingDown;
+};
+
+NS_IMPL_ISUPPORTS(VibratorRunnable, nsIRunnable, nsIObserver);
+
+bool VibratorRunnable::sShuttingDown = false;
+
+static StaticRefPtr<VibratorRunnable> sVibratorRunnable;
+
+NS_IMETHODIMP
+VibratorRunnable::Run()
+{
+  MonitorAutoLock lock(mMonitor);
+
+  // We currently assume that mMonitor.Wait(X) waits for X milliseconds.  But in
+  // reality, the kernel might not switch to this thread for some time after the
+  // wait expires.  So there's potential for some inaccuracy here.
+  //
+  // This doesn't worry me too much.  Note that we don't even start vibrating
+  // immediately when VibratorRunnable::Vibrate is called -- we go through a
+  // condvar onto another thread.  Better just to be chill about small errors in
+  // the timing here.
+
+  while (!sShuttingDown) {
+    if (mIndex < mPattern.Length()) {
+      uint32_t duration = mPattern[mIndex];
+      if (mIndex % 2 == 0) {
+        vibrator_on(duration);
+      }
+      mIndex++;
+      mMonitor.Wait(PR_MillisecondsToInterval(duration));
+    }
+    else {
+      mMonitor.Wait();
+    }
+  }
+  sVibratorRunnable = nullptr;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+VibratorRunnable::Observe(nsISupports *subject, const char *topic,
+                          const char16_t *data)
+{
+  MOZ_ASSERT(strcmp(topic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0);
+  MonitorAutoLock lock(mMonitor);
+  sShuttingDown = true;
+  mMonitor.Notify();
+
+  return NS_OK;
+}
+
+void
+VibratorRunnable::Vibrate(const nsTArray<uint32_t> &pattern)
+{
+  MonitorAutoLock lock(mMonitor);
+  mPattern = pattern;
+  mIndex = 0;
+  mMonitor.Notify();
+}
+
+void
+VibratorRunnable::CancelVibrate()
+{
+  MonitorAutoLock lock(mMonitor);
+  mPattern.Clear();
+  mPattern.AppendElement(0);
+  mIndex = 0;
+  mMonitor.Notify();
+}
+
+void
+EnsureVibratorThreadInitialized()
+{
+  if (sVibratorRunnable) {
+    return;
+  }
+
+  sVibratorRunnable = new VibratorRunnable();
+  nsCOMPtr<nsIThread> thread;
+  NS_NewThread(getter_AddRefs(thread), sVibratorRunnable);
+}
+
+} // namespace
+
+void
+Vibrate(const nsTArray<uint32_t> &pattern, const hal::WindowIdentifier &)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (VibratorRunnable::ShuttingDown()) {
+    return;
+  }
+  EnsureVibratorThreadInitialized();
+  sVibratorRunnable->Vibrate(pattern);
+}
+
+void
+CancelVibrate(const hal::WindowIdentifier &)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (VibratorRunnable::ShuttingDown()) {
+    return;
+  }
+  EnsureVibratorThreadInitialized();
+  sVibratorRunnable->CancelVibrate();
+}
+
+namespace {
+
+class BatteryUpdater : public Runnable {
+public:
+  NS_IMETHOD Run() override
+  {
+    hal::BatteryInformation info;
+    hal_impl::GetCurrentBatteryInformation(&info);
+
+    // Control the battery indicator (led light) here using BatteryInformation
+    // we just retrieved.
+    uint32_t color = 0; // Format: 0x00rrggbb.
+    if (info.charging() && (info.level() == 1)) {
+      // Charging and battery full.
+      color = BATTERY_FULL_ARGB;
+    } else if (info.charging() && (info.level() < 1)) {
+      // Charging but not full.
+      color = BATTERY_CHARGING_ARGB;
+    } // else turn off battery indicator.
+
+    LightConfiguration aConfig;
+    aConfig.light = eHalLightID_Battery;
+    aConfig.mode = eHalLightMode_User;
+    aConfig.flash = eHalLightFlash_None;
+    aConfig.flashOnMS = aConfig.flashOffMS = 0;
+    aConfig.color = color;
+
+    SetLight(eHalLightID_Battery, aConfig);
+
+    hal::NotifyBatteryChange(info);
+
+    {
+      // bug 975667
+      // Gecko gonk hal is required to emit battery charging/level notification via nsIObserverService.
+      // This is useful for XPCOM components that are not statically linked to Gecko and cannot call
+      // hal::EnableBatteryNotifications
+      nsCOMPtr<nsIObserverService> obsService = mozilla::services::GetObserverService();
+      nsCOMPtr<nsIWritablePropertyBag2> propbag =
+        do_CreateInstance("@mozilla.org/hash-property-bag;1");
+      if (obsService && propbag) {
+        propbag->SetPropertyAsBool(NS_LITERAL_STRING("charging"),
+                                   info.charging());
+        propbag->SetPropertyAsDouble(NS_LITERAL_STRING("level"),
+                                   info.level());
+
+        obsService->NotifyObservers(propbag, "gonkhal-battery-notifier", nullptr);
+      }
+    }
+
+    return NS_OK;
+  }
+};
+
+} // namespace
+
+class BatteryObserver final : public IUeventObserver
+{
+public:
+  NS_INLINE_DECL_REFCOUNTING(BatteryObserver)
+
+  BatteryObserver()
+    :mUpdater(new BatteryUpdater())
+  {
+  }
+
+  virtual void Notify(const NetlinkEvent &aEvent)
+  {
+    // this will run on IO thread
+    NetlinkEvent *event = const_cast<NetlinkEvent*>(&aEvent);
+    const char *subsystem = event->getSubsystem();
+    // e.g. DEVPATH=/devices/platform/sec-battery/power_supply/battery
+    const char *devpath = event->findParam("DEVPATH");
+    if (strcmp(subsystem, "power_supply") == 0 &&
+        strstr(devpath, "battery")) {
+      // aEvent will be valid only in this method.
+      NS_DispatchToMainThread(mUpdater);
+    }
+  }
+
+protected:
+  ~BatteryObserver() {}
+
+private:
+  RefPtr<BatteryUpdater> mUpdater;
+};
+
+// sBatteryObserver is owned by the IO thread. Only the IO thread may
+// create or destroy it.
+static StaticRefPtr<BatteryObserver> sBatteryObserver;
+
+static void
+RegisterBatteryObserverIOThread()
+{
+  MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
+  MOZ_ASSERT(!sBatteryObserver);
+
+  sBatteryObserver = new BatteryObserver();
+  RegisterUeventListener(sBatteryObserver);
+}
+
+void
+EnableBatteryNotifications()
+{
+  XRE_GetIOMessageLoop()->PostTask(
+      NewRunnableFunction(RegisterBatteryObserverIOThread));
+}
+
+static void
+UnregisterBatteryObserverIOThread()
+{
+  MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
+  MOZ_ASSERT(sBatteryObserver);
+
+  UnregisterUeventListener(sBatteryObserver);
+  sBatteryObserver = nullptr;
+}
+
+void
+DisableBatteryNotifications()
+{
+  XRE_GetIOMessageLoop()->PostTask(
+      NewRunnableFunction(UnregisterBatteryObserverIOThread));
+}
+
+static bool
+GetCurrentBatteryCharge(int* aCharge)
+{
+  bool success = ReadSysFile("/sys/class/power_supply/battery/capacity",
+                             aCharge);
+  if (!success) {
+    return false;
+  }
+
+  #ifdef DEBUG
+  if ((*aCharge < 0) || (*aCharge > 100)) {
+    HAL_LOG("charge level contains unknown value: %d", *aCharge);
+  }
+  #endif
+
+  return (*aCharge >= 0) && (*aCharge <= 100);
+}
+
+static bool
+GetCurrentBatteryCharging(int* aCharging)
+{
+  static const DebugOnly<int> BATTERY_NOT_CHARGING = 0;
+  static const int BATTERY_CHARGING_USB = 1;
+  static const int BATTERY_CHARGING_AC  = 2;
+
+  // Generic device support
+
+  int chargingSrc;
+  bool success =
+    ReadSysFile("/sys/class/power_supply/battery/charging_source", &chargingSrc);
+
+  if (success) {
+    #ifdef DEBUG
+    if (chargingSrc != BATTERY_NOT_CHARGING &&
+        chargingSrc != BATTERY_CHARGING_USB &&
+        chargingSrc != BATTERY_CHARGING_AC) {
+      HAL_LOG("charging_source contained unknown value: %d", chargingSrc);
+    }
+    #endif
+
+    *aCharging = (chargingSrc == BATTERY_CHARGING_USB ||
+                  chargingSrc == BATTERY_CHARGING_AC);
+    return true;
+  }
+
+  // Otoro device support
+
+  char chargingSrcString[16];
+
+  success = ReadSysFile("/sys/class/power_supply/battery/status",
+                        chargingSrcString, sizeof(chargingSrcString));
+  if (success) {
+    *aCharging = strcmp(chargingSrcString, "Charging") == 0 ||
+                 strcmp(chargingSrcString, "Full") == 0;
+    return true;
+  }
+
+  return false;
+}
+
+void
+GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo)
+{
+  int charge;
+  static bool previousCharging = false;
+  static double previousLevel = 0.0, remainingTime = 0.0;
+  static struct timespec lastLevelChange;
+  struct timespec now;
+  double dtime, dlevel;
+
+  if (GetCurrentBatteryCharge(&charge)) {
+    aBatteryInfo->level() = (double)charge / 100.0;
+  } else {
+    aBatteryInfo->level() = dom::battery::kDefaultLevel;
+  }
+
+  int charging;
+
+  if (GetCurrentBatteryCharging(&charging)) {
+    aBatteryInfo->charging() = charging;
+  } else {
+    aBatteryInfo->charging() = true;
+  }
+
+  if (aBatteryInfo->charging() != previousCharging){
+    aBatteryInfo->remainingTime() = dom::battery::kUnknownRemainingTime;
+    memset(&lastLevelChange, 0, sizeof(struct timespec));
+    remainingTime = 0.0;
+  }
+
+  if (aBatteryInfo->charging()) {
+    if (aBatteryInfo->level() == 1.0) {
+      aBatteryInfo->remainingTime() = dom::battery::kDefaultRemainingTime;
+    } else if (aBatteryInfo->level() != previousLevel){
+      if (lastLevelChange.tv_sec != 0) {
+        clock_gettime(CLOCK_MONOTONIC, &now);
+        dtime = now.tv_sec - lastLevelChange.tv_sec;
+        dlevel = aBatteryInfo->level() - previousLevel;
+
+        if (dlevel <= 0.0) {
+          aBatteryInfo->remainingTime() = dom::battery::kUnknownRemainingTime;
+        } else {
+          remainingTime = (double) round(dtime / dlevel * (1.0 - aBatteryInfo->level()));
+          aBatteryInfo->remainingTime() = remainingTime;
+        }
+
+        lastLevelChange = now;
+      } else { // lastLevelChange.tv_sec == 0
+        clock_gettime(CLOCK_MONOTONIC, &lastLevelChange);
+        aBatteryInfo->remainingTime() = dom::battery::kUnknownRemainingTime;
+      }
+
+    } else {
+      clock_gettime(CLOCK_MONOTONIC, &now);
+      dtime = now.tv_sec - lastLevelChange.tv_sec;
+      if (dtime < remainingTime) {
+        aBatteryInfo->remainingTime() = round(remainingTime - dtime);
+      } else {
+        aBatteryInfo->remainingTime() = dom::battery::kUnknownRemainingTime;
+      }
+
+    }
+
+  } else {
+    if (aBatteryInfo->level() == 0.0) {
+      aBatteryInfo->remainingTime() = dom::battery::kDefaultRemainingTime;
+    } else if (aBatteryInfo->level() != previousLevel){
+      if (lastLevelChange.tv_sec != 0) {
+        clock_gettime(CLOCK_MONOTONIC, &now);
+        dtime = now.tv_sec - lastLevelChange.tv_sec;
+        dlevel = previousLevel - aBatteryInfo->level();
+
+        if (dlevel <= 0.0) {
+          aBatteryInfo->remainingTime() = dom::battery::kUnknownRemainingTime;
+        } else {
+          remainingTime = (double) round(dtime / dlevel * aBatteryInfo->level());
+          aBatteryInfo->remainingTime() = remainingTime;
+        }
+
+        lastLevelChange = now;
+      } else { // lastLevelChange.tv_sec == 0
+        clock_gettime(CLOCK_MONOTONIC, &lastLevelChange);
+        aBatteryInfo->remainingTime() = dom::battery::kUnknownRemainingTime;
+      }
+
+    } else {
+      clock_gettime(CLOCK_MONOTONIC, &now);
+      dtime = now.tv_sec - lastLevelChange.tv_sec;
+      if (dtime < remainingTime) {
+        aBatteryInfo->remainingTime() = round(remainingTime - dtime);
+      } else {
+        aBatteryInfo->remainingTime() = dom::battery::kUnknownRemainingTime;
+      }
+
+    }
+  }
+
+  previousCharging = aBatteryInfo->charging();
+  previousLevel = aBatteryInfo->level();
+}
+
+namespace {
+
+// We can write to screenEnabledFilename to enable/disable the screen, but when
+// we read, we always get "mem"!  So we have to keep track ourselves whether
+// the screen is on or not.
+bool sScreenEnabled = true;
+
+// We can read wakeLockFilename to find out whether the cpu wake lock
+// is already acquired, but reading and parsing it is a lot more work
+// than tracking it ourselves, and it won't be accurate anyway (kernel
+// internal wake locks aren't counted here.)
+bool sCpuSleepAllowed = true;
+
+// Some CPU wake locks may be acquired internally in HAL. We use a counter to
+// keep track of these needs. Note we have to hold |sInternalLockCpuMutex|
+// when reading or writing this variable to ensure thread-safe.
+int32_t sInternalLockCpuCount = 0;
+
+} // namespace
+
+bool
+GetScreenEnabled()
+{
+  return sScreenEnabled;
+}
+
+void
+SetScreenEnabled(bool aEnabled)
+{
+  GetGonkDisplay()->SetEnabled(aEnabled);
+  sScreenEnabled = aEnabled;
+}
+
+bool
+GetKeyLightEnabled()
+{
+  LightConfiguration config;
+  bool ok = GetLight(eHalLightID_Buttons, &config);
+  if (ok) {
+    return (config.color != 0x00000000);
+  }
+  return false;
+}
+
+void
+SetKeyLightEnabled(bool aEnabled)
+{
+  LightConfiguration config;
+  config.mode = eHalLightMode_User;
+  config.flash = eHalLightFlash_None;
+  config.flashOnMS = config.flashOffMS = 0;
+  config.color = 0x00000000;
+
+  if (aEnabled) {
+    // Convert the value in [0, 1] to an int between 0 and 255 and then convert
+    // it to a color. Note that the high byte is FF, corresponding to the alpha
+    // channel.
+    double brightness = GetScreenBrightness();
+    uint32_t val = static_cast<int>(round(brightness * 255.0));
+    uint32_t color = (0xff<<24) + (val<<16) + (val<<8) + val;
+
+    config.color = color;
+  }
+
+  SetLight(eHalLightID_Buttons, config);
+  SetLight(eHalLightID_Keyboard, config);
+}
+
+double
+GetScreenBrightness()
+{
+  LightConfiguration config;
+  LightType light = eHalLightID_Backlight;
+
+  bool ok = GetLight(light, &config);
+  if (ok) {
+    // backlight is brightness only, so using one of the RGB elements as value.
+    int brightness = config.color & 0xFF;
+    return brightness / 255.0;
+  }
+  // If GetLight fails, it's because the light doesn't exist.  So return
+  // a value corresponding to "off".
+  return 0;
+}
+
+void
+SetScreenBrightness(double brightness)
+{
+  // Don't use De Morgan's law to push the ! into this expression; we want to
+  // catch NaN too.
+  if (!(0 <= brightness && brightness <= 1)) {
+    HAL_LOG("SetScreenBrightness: Dropping illegal brightness %f.", brightness);
+    return;
+  }
+
+  // Convert the value in [0, 1] to an int between 0 and 255 and convert to a color
+  // note that the high byte is FF, corresponding to the alpha channel.
+  uint32_t val = static_cast<int>(round(brightness * 255.0));
+  uint32_t color = (0xff<<24) + (val<<16) + (val<<8) + val;
+
+  LightConfiguration config;
+  config.mode = eHalLightMode_User;
+  config.flash = eHalLightFlash_None;
+  config.flashOnMS = config.flashOffMS = 0;
+  config.color = color;
+  SetLight(eHalLightID_Backlight, config);
+  if (GetKeyLightEnabled()) {
+    SetLight(eHalLightID_Buttons, config);
+    SetLight(eHalLightID_Keyboard, config);
+  }
+}
+
+static StaticMutex sInternalLockCpuMutex;
+
+static void
+UpdateCpuSleepState()
+{
+  const char *wakeLockFilename = "/sys/power/wake_lock";
+  const char *wakeUnlockFilename = "/sys/power/wake_unlock";
+
+  sInternalLockCpuMutex.AssertCurrentThreadOwns();
+  bool allowed = sCpuSleepAllowed && !sInternalLockCpuCount;
+  WriteSysFile(allowed ? wakeUnlockFilename : wakeLockFilename, "gecko");
+}
+
+static void
+InternalLockCpu() {
+  StaticMutexAutoLock lock(sInternalLockCpuMutex);
+  ++sInternalLockCpuCount;
+  UpdateCpuSleepState();
+}
+
+static void
+InternalUnlockCpu() {
+  StaticMutexAutoLock lock(sInternalLockCpuMutex);
+  --sInternalLockCpuCount;
+  UpdateCpuSleepState();
+}
+
+bool
+GetCpuSleepAllowed()
+{
+  return sCpuSleepAllowed;
+}
+
+void
+SetCpuSleepAllowed(bool aAllowed)
+{
+  StaticMutexAutoLock lock(sInternalLockCpuMutex);
+  sCpuSleepAllowed = aAllowed;
+  UpdateCpuSleepState();
+}
+
+void
+AdjustSystemClock(int64_t aDeltaMilliseconds)
+{
+  int fd;
+  struct timespec now;
+
+  if (aDeltaMilliseconds == 0) {
+    return;
+  }
+
+  // Preventing context switch before setting system clock
+  sched_yield();
+  clock_gettime(CLOCK_REALTIME, &now);
+  now.tv_sec += (time_t)(aDeltaMilliseconds / 1000LL);
+  now.tv_nsec += (long)((aDeltaMilliseconds % 1000LL) * NsecPerMsec);
+  if (now.tv_nsec >= NsecPerSec) {
+    now.tv_sec += 1;
+    now.tv_nsec -= NsecPerSec;
+  }
+
+  if (now.tv_nsec < 0) {
+    now.tv_nsec += NsecPerSec;
+    now.tv_sec -= 1;
+  }
+
+  do {
+    fd = open("/dev/alarm", O_RDWR);
+  } while (fd == -1 && errno == EINTR);
+  ScopedClose autoClose(fd);
+  if (fd < 0) {
+    HAL_LOG("Failed to open /dev/alarm: %s", strerror(errno));
+    return;
+  }
+
+  if (ioctl(fd, ANDROID_ALARM_SET_RTC, &now) < 0) {
+    HAL_LOG("ANDROID_ALARM_SET_RTC failed: %s", strerror(errno));
+  }
+
+  hal::NotifySystemClockChange(aDeltaMilliseconds);
+}
+
+int32_t
+GetTimezoneOffset()
+{
+  PRExplodedTime prTime;
+  PR_ExplodeTime(PR_Now(), PR_LocalTimeParameters, &prTime);
+
+  // Daylight saving time (DST) will be taken into account.
+  int32_t offset = prTime.tm_params.tp_gmt_offset;
+  offset += prTime.tm_params.tp_dst_offset;
+
+  // Returns the timezone offset relative to UTC in minutes.
+  return -(offset / 60);
+}
+
+static int32_t sKernelTimezoneOffset = 0;
+
+static void
+UpdateKernelTimezone(int32_t timezoneOffset)
+{
+  if (sKernelTimezoneOffset == timezoneOffset) {
+    return;
+  }
+
+  // Tell the kernel about the new time zone as well, so that FAT filesystems
+  // will get local timestamps rather than UTC timestamps.
+  //
+  // We assume that /init.rc has a sysclktz entry so that settimeofday has
+  // already been called once before we call it (there is a side-effect in
+  // the kernel the very first time settimeofday is called where it does some
+  // special processing if you only set the timezone).
+  struct timezone tz;
+  memset(&tz, 0, sizeof(tz));
+  tz.tz_minuteswest = timezoneOffset;
+  settimeofday(nullptr, &tz);
+  sKernelTimezoneOffset = timezoneOffset;
+}
+
+void
+SetTimezone(const nsCString& aTimezoneSpec)
+{
+  if (aTimezoneSpec.Equals(GetTimezone())) {
+    // Even though the timezone hasn't changed, we still need to tell the
+    // kernel what the current timezone is. The timezone is persisted in
+    // a property and doesn't change across reboots, but the kernel still
+    // needs to be updated on every boot.
+    UpdateKernelTimezone(GetTimezoneOffset());
+    return;
+  }
+
+  int32_t oldTimezoneOffsetMinutes = GetTimezoneOffset();
+  property_set("persist.sys.timezone", aTimezoneSpec.get());
+  // This function is automatically called by the other time conversion
+  // functions that depend on the timezone. To be safe, we call it manually.
+  tzset();
+  int32_t newTimezoneOffsetMinutes = GetTimezoneOffset();
+  UpdateKernelTimezone(newTimezoneOffsetMinutes);
+  hal::NotifySystemTimezoneChange(
+    hal::SystemTimezoneChangeInformation(
+      oldTimezoneOffsetMinutes, newTimezoneOffsetMinutes));
+}
+
+nsCString
+GetTimezone()
+{
+  char timezone[32];
+  property_get("persist.sys.timezone", timezone, "");
+  return nsCString(timezone);
+}
+
+void
+EnableSystemClockChangeNotifications()
+{
+}
+
+void
+DisableSystemClockChangeNotifications()
+{
+}
+
+void
+EnableSystemTimezoneChangeNotifications()
+{
+}
+
+void
+DisableSystemTimezoneChangeNotifications()
+{
+}
+
+// Nothing to do here.  Gonk widgetry always listens for screen
+// orientation changes.
+void
+EnableScreenConfigurationNotifications()
+{
+}
+
+void
+DisableScreenConfigurationNotifications()
+{
+}
+
+void
+GetCurrentScreenConfiguration(hal::ScreenConfiguration* aScreenConfiguration)
+{
+  RefPtr<nsScreenGonk> screen = nsScreenManagerGonk::GetPrimaryScreen();
+  *aScreenConfiguration = screen->GetConfiguration();
+}
+
+bool
+LockScreenOrientation(const dom::ScreenOrientationInternal& aOrientation)
+{
+  return OrientationObserver::GetInstance()->LockScreenOrientation(aOrientation);
+}
+
+void
+UnlockScreenOrientation()
+{
+  OrientationObserver::GetInstance()->UnlockScreenOrientation();
+}
+
+// This thread will wait for the alarm firing by a blocking IO.
+static pthread_t sAlarmFireWatcherThread;
+
+// If |sAlarmData| is non-null, it's owned by the alarm-watcher thread.
+struct AlarmData {
+public:
+  AlarmData(int aFd) : mFd(aFd),
+                       mGeneration(sNextGeneration++),
+                       mShuttingDown(false) {}
+  ScopedClose mFd;
+  int mGeneration;
+  bool mShuttingDown;
+
+  static int sNextGeneration;
+
+};
+
+int AlarmData::sNextGeneration = 0;
+
+AlarmData* sAlarmData = nullptr;
+
+class AlarmFiredEvent : public Runnable {
+public:
+  AlarmFiredEvent(int aGeneration) : mGeneration(aGeneration) {}
+
+  NS_IMETHOD Run() override {
+    // Guard against spurious notifications caused by an alarm firing
+    // concurrently with it being disabled.
+    if (sAlarmData && !sAlarmData->mShuttingDown &&
+        mGeneration == sAlarmData->mGeneration) {
+      hal::NotifyAlarmFired();
+    }
+    // The fired alarm event has been delivered to the observer (if needed);
+    // we can now release a CPU wake lock.
+    InternalUnlockCpu();
+    return NS_OK;
+  }
+
+private:
+  int mGeneration;
+};
+
+// Runs on alarm-watcher thread.
+static void
+DestroyAlarmData(void* aData)
+{
+  AlarmData* alarmData = static_cast<AlarmData*>(aData);
+  delete alarmData;
+}
+
+// Runs on alarm-watcher thread.
+void ShutDownAlarm(int aSigno)
+{
+  if (aSigno == SIGUSR1 && sAlarmData) {
+    sAlarmData->mShuttingDown = true;
+  }
+  return;
+}
+
+static void*
+WaitForAlarm(void* aData)
+{
+  pthread_cleanup_push(DestroyAlarmData, aData);
+
+  AlarmData* alarmData = static_cast<AlarmData*>(aData);
+
+  while (!alarmData->mShuttingDown) {
+    int alarmTypeFlags = 0;
+
+    // ALARM_WAIT apparently will block even if an alarm hasn't been
+    // programmed, although this behavior doesn't seem to be
+    // documented.  We rely on that here to avoid spinning the CPU
+    // while awaiting an alarm to be programmed.
+    do {
+      alarmTypeFlags = ioctl(alarmData->mFd, ANDROID_ALARM_WAIT);
+    } while (alarmTypeFlags < 0 && errno == EINTR &&
+             !alarmData->mShuttingDown);
+
+    if (!alarmData->mShuttingDown && alarmTypeFlags >= 0 &&
+        (alarmTypeFlags & ANDROID_ALARM_RTC_WAKEUP_MASK)) {
+      // To make sure the observer can get the alarm firing notification
+      // *on time* (the system won't sleep during the process in any way),
+      // we need to acquire a CPU wake lock before firing the alarm event.
+      InternalLockCpu();
+      RefPtr<AlarmFiredEvent> event =
+        new AlarmFiredEvent(alarmData->mGeneration);
+      NS_DispatchToMainThread(event);
+    }
+  }
+
+  pthread_cleanup_pop(1);
+  return nullptr;
+}
+
+bool
+EnableAlarm()
+{
+  MOZ_ASSERT(!sAlarmData);
+
+  int alarmFd = open("/dev/alarm", O_RDWR);
+  if (alarmFd < 0) {
+    HAL_LOG("Failed to open alarm device: %s.", strerror(errno));
+    return false;
+  }
+
+  UniquePtr<AlarmData> alarmData = MakeUnique<AlarmData>(alarmFd);
+
+  struct sigaction actions;
+  memset(&actions, 0, sizeof(actions));
+  sigemptyset(&actions.sa_mask);
+  actions.sa_flags = 0;
+  actions.sa_handler = ShutDownAlarm;
+  if (sigaction(SIGUSR1, &actions, nullptr)) {
+    HAL_LOG("Failed to set SIGUSR1 signal for alarm-watcher thread.");
+    return false;
+  }
+
+  pthread_attr_t attr;
+  pthread_attr_init(&attr);
+  pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+
+  int status = pthread_create(&sAlarmFireWatcherThread, &attr, WaitForAlarm,
+                              alarmData.get());
+  if (status) {
+    alarmData.reset();
+    HAL_LOG("Failed to create alarm-watcher thread. Status: %d.", status);
+    return false;
+  }
+
+  pthread_attr_destroy(&attr);
+
+  // The thread owns this now.  We only hold a pointer.
+  sAlarmData = alarmData.release();
+  return true;
+}
+
+void
+DisableAlarm()
+{
+  MOZ_ASSERT(sAlarmData);
+
+  // NB: this must happen-before the thread cancellation.
+  sAlarmData = nullptr;
+
+  // The cancel will interrupt the thread and destroy it, freeing the
+  // data pointed at by sAlarmData.
+  DebugOnly<int> err = pthread_kill(sAlarmFireWatcherThread, SIGUSR1);
+  MOZ_ASSERT(!err);
+}
+
+bool
+SetAlarm(int32_t aSeconds, int32_t aNanoseconds)
+{
+  if (!sAlarmData) {
+    HAL_LOG("We should have enabled the alarm.");
+    return false;
+  }
+
+  struct timespec ts;
+  ts.tv_sec = aSeconds;
+  ts.tv_nsec = aNanoseconds;
+
+  // Currently we only support RTC wakeup alarm type.
+  const int result = ioctl(sAlarmData->mFd,
+                           ANDROID_ALARM_SET(ANDROID_ALARM_RTC_WAKEUP), &ts);
+
+  if (result < 0) {
+    HAL_LOG("Unable to set alarm: %s.", strerror(errno));
+    return false;
+  }
+
+  return true;
+}
+
+static int
+OomAdjOfOomScoreAdj(int aOomScoreAdj)
+{
+  // Convert OOM adjustment from the domain of /proc/<pid>/oom_score_adj
+  // to the domain of /proc/<pid>/oom_adj.
+
+  int adj;
+
+  if (aOomScoreAdj < 0) {
+    adj = (OOM_DISABLE * aOomScoreAdj) / OOM_SCORE_ADJ_MIN;
+  } else {
+    adj = (OOM_ADJUST_MAX * aOomScoreAdj) / OOM_SCORE_ADJ_MAX;
+  }
+
+  return adj;
+}
+
+static void
+RoundOomScoreAdjUpWithLRU(int& aOomScoreAdj, uint32_t aLRU)
+{
+  // We want to add minimum value to round OomScoreAdj up according to
+  // the steps by aLRU.
+  aOomScoreAdj +=
+    ceil(((float)OOM_SCORE_ADJ_MAX / OOM_ADJUST_MAX) * aLRU);
+}
+
+#define OOM_LOG(level, args...) __android_log_print(level, "OomLogger", ##args)
+class OomVictimLogger final
+  : public nsIObserver
+{
+public:
+  OomVictimLogger()
+    : mLastLineChecked(-1.0),
+      mRegexes(nullptr)
+  {
+    // Enable timestamps in kernel's printk
+    WriteSysFile("/sys/module/printk/parameters/time", "Y");
+  }
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIOBSERVER
+
+protected:
+  ~OomVictimLogger() {}
+
+private:
+  double mLastLineChecked;
+  UniqueFreePtr<regex_t> mRegexes;
+};
+NS_IMPL_ISUPPORTS(OomVictimLogger, nsIObserver);
+
+NS_IMETHODIMP
+OomVictimLogger::Observe(
+  nsISupports* aSubject,
+  const char* aTopic,
+  const char16_t* aData)
+{
+  nsDependentCString event_type(aTopic);
+  if (!event_type.EqualsLiteral("ipc:content-shutdown")) {
+    return NS_OK;
+  }
+
+  // OOM message finding regexes
+  const char* const regexes_raw[] = {
+    ".*select.*to kill.*",
+    ".*send sigkill to.*",
+    ".*lowmem_shrink.*",
+    ".*[Oo]ut of [Mm]emory.*",
+    ".*[Kk]ill [Pp]rocess.*",
+    ".*[Kk]illed [Pp]rocess.*",
+    ".*oom-killer.*",
+    // The regexes below are for the output of dump_task from oom_kill.c
+    // 1st - title 2nd - body lines (8 ints and a string)
+    // oom_adj and oom_score_adj can be negative
+    "\\[ pid \\]   uid  tgid total_vm      rss cpu oom_adj oom_score_adj name",
+    "\\[.*[0-9][0-9]*\\][ ]*[0-9][0-9]*[ ]*[0-9][0-9]*[ ]*[0-9][0-9]*[ ]*[0-9][0-9]*[ ]*[0-9][0-9]*[ ]*.[0-9][0-9]*[ ]*.[0-9][0-9]*.*"
+  };
+  const size_t regex_count = ArrayLength(regexes_raw);
+
+  // Compile our regex just in time
+  if (!mRegexes) {
+    UniqueFreePtr<regex_t> regexes(
+      static_cast<regex_t*>(malloc(sizeof(regex_t) * regex_count))
+    );
+    mRegexes.swap(regexes);
+    for (size_t i = 0; i < regex_count; i++) {
+      int compilation_err =
+        regcomp(&(mRegexes.get()[i]), regexes_raw[i], REG_NOSUB);
+      if (compilation_err) {
+        OOM_LOG(ANDROID_LOG_ERROR, "Cannot compile regex \"%s\"\n", regexes_raw[i]);
+        return NS_OK;
+      }
+    }
+  }
+
+#ifndef KLOG_SIZE_BUFFER
+  // Upstream bionic in commit
+  // e249b059637b49a285ed9f58a2a18bfd054e5d95
+  // deprecated the old klog defs.
+  // Our current bionic does not hit this
+  // change yet so handle the future change.
+  // (ICS doesn't have KLOG_SIZE_BUFFER but
+  // JB and onwards does.)
+  #define KLOG_SIZE_BUFFER KLOG_WRITE
+#endif
+  // Retreive kernel log
+  int msg_buf_size = klogctl(KLOG_SIZE_BUFFER, NULL, 0);
+  UniqueFreePtr<char> msg_buf(static_cast<char *>(malloc(msg_buf_size + 1)));
+  int read_size = klogctl(KLOG_READ_ALL, msg_buf.get(), msg_buf_size);
+
+  // Turn buffer into cstring
+  read_size = read_size > msg_buf_size ? msg_buf_size : read_size;
+  msg_buf.get()[read_size] = '\0';
+
+  // Foreach line
+  char* line_end;
+  char* line_begin = msg_buf.get();
+  for (; (line_end = strchr(line_begin, '\n')); line_begin = line_end + 1) {
+    // make line into cstring
+    *line_end = '\0';
+
+    // Note: Kernel messages look like:
+    // <5>[63648.286409] sd 35:0:0:0: Attached scsi generic sg1 type 0
+    // 5 is the loging level
+    // [*] is the time timestamp, seconds since boot
+    // last comes the logged message
+
+    // Since the logging level can be a string we must
+    // skip it since scanf lacks wildcard matching
+    char*  timestamp_begin = strchr(line_begin, '[');
+    char   after_float;
+    double lineTimestamp = -1;
+    bool   lineTimestampFound = false;
+    if (timestamp_begin &&
+         // Note: scanf treats a ' ' as [ ]*
+         // Note: scanf treats [ %lf] as [ %lf thus we must check
+         // for the closing bracket outselves.
+         2 == sscanf(timestamp_begin, "[ %lf%c", &lineTimestamp, &after_float) &&
+         after_float == ']') {
+      if (lineTimestamp <= mLastLineChecked) {
+        continue;
+      }
+
+      lineTimestampFound = true;
+      mLastLineChecked = lineTimestamp;
+    }
+
+    // Log interesting lines
+    for (size_t i = 0; i < regex_count; i++) {
+      int matching = !regexec(&(mRegexes.get()[i]), line_begin, 0, NULL, 0);
+      if (matching) {
+        // Log content of kernel message. We try to skip the ], but if for
+        // some reason (most likely due to buffer overflow/wraparound), we
+        // can't find the ] then we just log the entire line.
+        char* endOfTimestamp = strchr(line_begin, ']');
+        if (endOfTimestamp && endOfTimestamp[1] == ' ') {
+          // skip the ] and the space that follows it
+          line_begin = endOfTimestamp + 2;
+        }
+        if (!lineTimestampFound) {
+          OOM_LOG(ANDROID_LOG_WARN, "following kill message may be a duplicate");
+        }
+        OOM_LOG(ANDROID_LOG_ERROR, "[Kill]: %s\n", line_begin);
+        break;
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+/**
+ * Wraps a particular ProcessPriority, giving us easy access to the prefs that
+ * are relevant to it.
+ *
+ * Creating a PriorityClass also ensures that the control group is created.
+ */
+class PriorityClass
+{
+public:
+  /**
+   * Create a PriorityClass for the given ProcessPriority.  This implicitly
+   * reads the relevant prefs and opens the cgroup.procs file of the relevant
+   * control group caching its file descriptor for later use.
+   */
+  PriorityClass(ProcessPriority aPriority);
+
+  /**
+   * Closes the file descriptor for the cgroup.procs file of the associated
+   * control group.
+   */
+  ~PriorityClass();
+
+  PriorityClass(const PriorityClass& aOther);
+  PriorityClass& operator=(const PriorityClass& aOther);
+
+  ProcessPriority Priority()
+  {
+    return mPriority;
+  }
+
+  int32_t OomScoreAdj()
+  {
+    return clamped<int32_t>(mOomScoreAdj, OOM_SCORE_ADJ_MIN, OOM_SCORE_ADJ_MAX);
+  }
+
+  int32_t KillUnderKB()
+  {
+    return mKillUnderKB;
+  }
+
+  nsCString CGroup()
+  {
+    return mGroup;
+  }
+
+  /**
+   * Adds a process to this priority class, this moves the process' PID into
+   * the associated control group.
+   *
+   * @param aPid The PID of the process to be added.
+   */
+  void AddProcess(int aPid);
+
+private:
+  ProcessPriority mPriority;
+  int32_t mOomScoreAdj;
+  int32_t mKillUnderKB;
+  int mCpuCGroupProcsFd;
+  int mMemCGroupProcsFd;
+  nsCString mGroup;
+
+  /**
+   * Return a string that identifies where we can find the value of aPref
+   * that's specific to mPriority.  For example, we might return
+   * "hal.processPriorityManager.gonk.FOREGROUND_HIGH.oomScoreAdjust".
+   */
+  nsCString PriorityPrefName(const char* aPref)
+  {
+    return nsPrintfCString("hal.processPriorityManager.gonk.%s.%s",
+                           ProcessPriorityToString(mPriority), aPref);
+  }
+
+  /**
+   * Get the full path of the cgroup.procs file associated with the group.
+   */
+  nsCString CpuCGroupProcsFilename()
+  {
+    nsCString cgroupName = mGroup;
+
+    /* If mGroup is empty, our cgroup.procs file is the root procs file,
+     * located at /dev/cpuctl/cgroup.procs.  Otherwise our procs file is
+     * /dev/cpuctl/NAME/cgroup.procs. */
+
+    if (!mGroup.IsEmpty()) {
+      cgroupName.AppendLiteral("/");
+    }
+
+    return NS_LITERAL_CSTRING("/dev/cpuctl/") + cgroupName +
+           NS_LITERAL_CSTRING("cgroup.procs");
+  }
+
+  nsCString MemCGroupProcsFilename()
+  {
+    nsCString cgroupName = mGroup;
+
+    /* If mGroup is empty, our cgroup.procs file is the root procs file,
+     * located at /sys/fs/cgroup/memory/cgroup.procs.  Otherwise our procs
+     * file is /sys/fs/cgroup/memory/NAME/cgroup.procs. */
+
+    if (!mGroup.IsEmpty()) {
+      cgroupName.AppendLiteral("/");
+    }
+
+    return NS_LITERAL_CSTRING("/sys/fs/cgroup/memory/") + cgroupName +
+           NS_LITERAL_CSTRING("cgroup.procs");
+  }
+
+  int OpenCpuCGroupProcs()
+  {
+    return open(CpuCGroupProcsFilename().get(), O_WRONLY);
+  }
+
+  int OpenMemCGroupProcs()
+  {
+    return open(MemCGroupProcsFilename().get(), O_WRONLY);
+  }
+};
+
+/**
+ * Try to create the cgroup for the given PriorityClass, if it doesn't already
+ * exist.  This essentially implements mkdir -p; that is, we create parent
+ * cgroups as necessary.  The group parameters are also set according to
+ * the corresponding preferences.
+ *
+ * @param aGroup The name of the group.
+ * @return true if we successfully created the cgroup, or if it already
+ * exists.  Otherwise, return false.
+ */
+static bool
+EnsureCpuCGroupExists(const nsACString &aGroup)
+{
+  NS_NAMED_LITERAL_CSTRING(kDevCpuCtl, "/dev/cpuctl/");
+  NS_NAMED_LITERAL_CSTRING(kSlash, "/");
+
+  nsAutoCString groupName(aGroup);
+  HAL_LOG("EnsureCpuCGroupExists for group '%s'", groupName.get());
+
+  nsAutoCString prefPrefix("hal.processPriorityManager.gonk.cgroups.");
+
+  /* If cgroup is not empty, append the cgroup name and a dot to obtain the
+   * group specific preferences. */
+  if (!aGroup.IsEmpty()) {
+    prefPrefix += aGroup + NS_LITERAL_CSTRING(".");
+  }
+
+  nsAutoCString cpuSharesPref(prefPrefix + NS_LITERAL_CSTRING("cpu_shares"));
+  int cpuShares = Preferences::GetInt(cpuSharesPref.get());
+
+  nsAutoCString cpuNotifyOnMigratePref(prefPrefix
+    + NS_LITERAL_CSTRING("cpu_notify_on_migrate"));
+  int cpuNotifyOnMigrate = Preferences::GetInt(cpuNotifyOnMigratePref.get());
+
+  // Create mCGroup and its parent directories, as necessary.
+  nsCString cgroupIter = aGroup + kSlash;
+
+  int32_t offset = 0;
+  while ((offset = cgroupIter.FindChar('/', offset)) != -1) {
+    nsAutoCString path = kDevCpuCtl + Substring(cgroupIter, 0, offset);
+    int rv = mkdir(path.get(), 0744);
+
+    if (rv == -1 && errno != EEXIST) {
+      HAL_LOG("Could not create the %s control group.", path.get());
+      return false;
+    }
+
+    offset++;
+  }
+  HAL_LOG("EnsureCpuCGroupExists created group '%s'", groupName.get());
+
+  nsAutoCString pathPrefix(kDevCpuCtl + aGroup + kSlash);
+  nsAutoCString cpuSharesPath(pathPrefix + NS_LITERAL_CSTRING("cpu.shares"));
+  if (cpuShares && !WriteSysFile(cpuSharesPath.get(),
+                                 nsPrintfCString("%d", cpuShares).get())) {
+    HAL_LOG("Could not set the cpu share for group %s", cpuSharesPath.get());
+    return false;
+  }
+
+  nsAutoCString notifyOnMigratePath(pathPrefix
+    + NS_LITERAL_CSTRING("cpu.notify_on_migrate"));
+  if (!WriteSysFile(notifyOnMigratePath.get(),
+                    nsPrintfCString("%d", cpuNotifyOnMigrate).get())) {
+    HAL_LOG("Could not set the cpu migration notification flag for group %s",
+            notifyOnMigratePath.get());
+    return false;
+  }
+
+  return true;
+}
+
+static bool
+EnsureMemCGroupExists(const nsACString &aGroup)
+{
+  NS_NAMED_LITERAL_CSTRING(kMemCtl, "/sys/fs/cgroup/memory/");
+  NS_NAMED_LITERAL_CSTRING(kSlash, "/");
+
+  nsAutoCString groupName(aGroup);
+  HAL_LOG("EnsureMemCGroupExists for group '%s'", groupName.get());
+
+  nsAutoCString prefPrefix("hal.processPriorityManager.gonk.cgroups.");
+
+  /* If cgroup is not empty, append the cgroup name and a dot to obtain the
+   * group specific preferences. */
+  if (!aGroup.IsEmpty()) {
+    prefPrefix += aGroup + NS_LITERAL_CSTRING(".");
+  }
+
+  nsAutoCString memSwappinessPref(prefPrefix + NS_LITERAL_CSTRING("memory_swappiness"));
+  int memSwappiness = Preferences::GetInt(memSwappinessPref.get());
+
+  // Create mCGroup and its parent directories, as necessary.
+  nsCString cgroupIter = aGroup + kSlash;
+
+  int32_t offset = 0;
+  while ((offset = cgroupIter.FindChar('/', offset)) != -1) {
+    nsAutoCString path = kMemCtl + Substring(cgroupIter, 0, offset);
+    int rv = mkdir(path.get(), 0744);
+
+    if (rv == -1 && errno != EEXIST) {
+      HAL_LOG("Could not create the %s control group.", path.get());
+      return false;
+    }
+
+    offset++;
+  }
+  HAL_LOG("EnsureMemCGroupExists created group '%s'", groupName.get());
+
+  nsAutoCString pathPrefix(kMemCtl + aGroup + kSlash);
+  nsAutoCString memSwappinessPath(pathPrefix + NS_LITERAL_CSTRING("memory.swappiness"));
+  if (!WriteSysFile(memSwappinessPath.get(),
+                    nsPrintfCString("%d", memSwappiness).get())) {
+    HAL_LOG("Could not set the memory.swappiness for group %s", memSwappinessPath.get());
+    return false;
+  }
+  HAL_LOG("Set memory.swappiness for group %s to %d", memSwappinessPath.get(), memSwappiness);
+
+  return true;
+}
+
+PriorityClass::PriorityClass(ProcessPriority aPriority)
+  : mPriority(aPriority)
+  , mOomScoreAdj(0)
+  , mKillUnderKB(0)
+  , mCpuCGroupProcsFd(-1)
+  , mMemCGroupProcsFd(-1)
+{
+  DebugOnly<nsresult> rv;
+
+  rv = Preferences::GetInt(PriorityPrefName("OomScoreAdjust").get(),
+                           &mOomScoreAdj);
+  MOZ_ASSERT(NS_SUCCEEDED(rv), "Missing oom_score_adj preference");
+
+  rv = Preferences::GetInt(PriorityPrefName("KillUnderKB").get(),
+                           &mKillUnderKB);
+
+  rv = Preferences::GetCString(PriorityPrefName("cgroup").get(), &mGroup);
+  MOZ_ASSERT(NS_SUCCEEDED(rv), "Missing control group preference");
+
+  if (EnsureCpuCGroupExists(mGroup)) {
+    mCpuCGroupProcsFd = OpenCpuCGroupProcs();
+  }
+  if (EnsureMemCGroupExists(mGroup)) {
+    mMemCGroupProcsFd = OpenMemCGroupProcs();
+  }
+}
+
+PriorityClass::~PriorityClass()
+{
+  if (mCpuCGroupProcsFd != -1) {
+    close(mCpuCGroupProcsFd);
+  }
+  if (mMemCGroupProcsFd != -1) {
+    close(mMemCGroupProcsFd);
+  }
+}
+
+PriorityClass::PriorityClass(const PriorityClass& aOther)
+  : mPriority(aOther.mPriority)
+  , mOomScoreAdj(aOther.mOomScoreAdj)
+  , mKillUnderKB(aOther.mKillUnderKB)
+  , mGroup(aOther.mGroup)
+{
+  mCpuCGroupProcsFd = OpenCpuCGroupProcs();
+  mMemCGroupProcsFd = OpenMemCGroupProcs();
+}
+
+PriorityClass& PriorityClass::operator=(const PriorityClass& aOther)
+{
+  mPriority = aOther.mPriority;
+  mOomScoreAdj = aOther.mOomScoreAdj;
+  mKillUnderKB = aOther.mKillUnderKB;
+  mGroup = aOther.mGroup;
+  mCpuCGroupProcsFd = OpenCpuCGroupProcs();
+  mMemCGroupProcsFd = OpenMemCGroupProcs();
+  return *this;
+}
+
+void PriorityClass::AddProcess(int aPid)
+{
+  if (mCpuCGroupProcsFd >= 0) {
+    nsPrintfCString str("%d", aPid);
+
+    if (write(mCpuCGroupProcsFd, str.get(), strlen(str.get())) < 0) {
+      HAL_ERR("Couldn't add PID %d to the %s cpu control group", aPid, mGroup.get());
+    }
+  }
+  if (mMemCGroupProcsFd >= 0) {
+    nsPrintfCString str("%d", aPid);
+
+    if (write(mMemCGroupProcsFd, str.get(), strlen(str.get())) < 0) {
+      HAL_ERR("Couldn't add PID %d to the %s memory control group", aPid, mGroup.get());
+    }
+  }
+}
+
+/**
+ * Get the PriorityClass associated with the given ProcessPriority.
+ *
+ * If you pass an invalid ProcessPriority value, we return null.
+ *
+ * The pointers returned here are owned by GetPriorityClass (don't free them
+ * yourself).  They are guaranteed to stick around until shutdown.
+ */
+PriorityClass*
+GetPriorityClass(ProcessPriority aPriority)
+{
+  static StaticAutoPtr<nsTArray<PriorityClass>> priorityClasses;
+
+  // Initialize priorityClasses if this is the first time we're running this
+  // method.
+  if (!priorityClasses) {
+    priorityClasses = new nsTArray<PriorityClass>();
+    ClearOnShutdown(&priorityClasses);
+
+    for (int32_t i = 0; i < NUM_PROCESS_PRIORITY; i++) {
+      priorityClasses->AppendElement(PriorityClass(ProcessPriority(i)));
+    }
+  }
+
+  if (aPriority < 0 ||
+      static_cast<uint32_t>(aPriority) >= priorityClasses->Length()) {
+    return nullptr;
+  }
+
+  return &(*priorityClasses)[aPriority];
+}
+
+static void
+EnsureKernelLowMemKillerParamsSet()
+{
+  static bool kernelLowMemKillerParamsSet;
+  if (kernelLowMemKillerParamsSet) {
+    return;
+  }
+  kernelLowMemKillerParamsSet = true;
+
+  HAL_LOG("Setting kernel's low-mem killer parameters.");
+
+  // Set /sys/module/lowmemorykiller/parameters/{adj,minfree,notify_trigger}
+  // according to our prefs.  These files let us tune when the kernel kills
+  // processes when we're low on memory, and when it notifies us that we're
+  // running low on available memory.
+  //
+  // adj and minfree are both comma-separated lists of integers.  If adj="A,B"
+  // and minfree="X,Y", then the kernel will kill processes with oom_adj
+  // A or higher once we have fewer than X pages of memory free, and will kill
+  // processes with oom_adj B or higher once we have fewer than Y pages of
+  // memory free.
+  //
+  // notify_trigger is a single integer.   If we set notify_trigger=Z, then
+  // we'll get notified when there are fewer than Z pages of memory free.  (See
+  // GonkMemoryPressureMonitoring.cpp.)
+
+  // Build the adj and minfree strings.
+  nsAutoCString adjParams;
+  nsAutoCString minfreeParams;
+
+  DebugOnly<int32_t> lowerBoundOfNextOomScoreAdj = OOM_SCORE_ADJ_MIN - 1;
+  DebugOnly<int32_t> lowerBoundOfNextKillUnderKB = 0;
+  int32_t countOfLowmemorykillerParametersSets = 0;
+
+  long page_size = sysconf(_SC_PAGESIZE);
+
+  for (int i = NUM_PROCESS_PRIORITY - 1; i >= 0; i--) {
+    // The system doesn't function correctly if we're missing these prefs, so
+    // crash loudly.
+
+    PriorityClass* pc = GetPriorityClass(static_cast<ProcessPriority>(i));
+
+    int32_t oomScoreAdj = pc->OomScoreAdj();
+    int32_t killUnderKB = pc->KillUnderKB();
+
+    if (killUnderKB == 0) {
+      // ProcessPriority values like PROCESS_PRIORITY_FOREGROUND_KEYBOARD,
+      // which has only OomScoreAdjust but lacks KillUnderMB value, will not
+      // create new LMK parameters.
+      continue;
+    }
+
+    // The LMK in kernel silently malfunctions if we assign the parameters
+    // in non-increasing order, so we add this assertion here. See bug 887192.
+    MOZ_ASSERT(oomScoreAdj > lowerBoundOfNextOomScoreAdj);
+    MOZ_ASSERT(killUnderKB > lowerBoundOfNextKillUnderKB);
+
+    // The LMK in kernel only accept 6 sets of LMK parameters. See bug 914728.
+    MOZ_ASSERT(countOfLowmemorykillerParametersSets < 6);
+
+    // adj is in oom_adj units.
+    adjParams.AppendPrintf("%d,", OomAdjOfOomScoreAdj(oomScoreAdj));
+
+    // minfree is in pages.
+    minfreeParams.AppendPrintf("%ld,", killUnderKB * 1024 / page_size);
+
+    lowerBoundOfNextOomScoreAdj = oomScoreAdj;
+    lowerBoundOfNextKillUnderKB = killUnderKB;
+    countOfLowmemorykillerParametersSets++;
+  }
+
+  // Strip off trailing commas.
+  adjParams.Cut(adjParams.Length() - 1, 1);
+  minfreeParams.Cut(minfreeParams.Length() - 1, 1);
+  if (!adjParams.IsEmpty() && !minfreeParams.IsEmpty()) {
+    WriteSysFile("/sys/module/lowmemorykiller/parameters/adj", adjParams.get());
+    WriteSysFile("/sys/module/lowmemorykiller/parameters/minfree",
+                 minfreeParams.get());
+  }
+
+  // Set the low-memory-notification threshold.
+  int32_t lowMemNotifyThresholdKB;
+  if (NS_SUCCEEDED(Preferences::GetInt(
+        "hal.processPriorityManager.gonk.notifyLowMemUnderKB",
+        &lowMemNotifyThresholdKB))) {
+
+    // notify_trigger is in pages.
+    WriteSysFile("/sys/module/lowmemorykiller/parameters/notify_trigger",
+      nsPrintfCString("%ld", lowMemNotifyThresholdKB * 1024 / page_size).get());
+  }
+
+  // Ensure OOM events appear in logcat
+  RefPtr<OomVictimLogger> oomLogger = new OomVictimLogger();
+  nsCOMPtr<nsIObserverService> os = services::GetObserverService();
+  if (os) {
+    os->AddObserver(oomLogger, "ipc:content-shutdown", false);
+  }
+}
+
+void
+SetProcessPriority(int aPid, ProcessPriority aPriority, uint32_t aLRU)
+{
+  HAL_LOG("SetProcessPriority(pid=%d, priority=%d, LRU=%u)",
+          aPid, aPriority, aLRU);
+
+  // If this is the first time SetProcessPriority was called, set the kernel's
+  // OOM parameters according to our prefs.
+  //
+  // We could/should do this on startup instead of waiting for the first
+  // SetProcessPriorityCall.  But in practice, the master process needs to set
+  // its priority early in the game, so we can reasonably rely on
+  // SetProcessPriority being called early in startup.
+  EnsureKernelLowMemKillerParamsSet();
+
+  PriorityClass* pc = GetPriorityClass(aPriority);
+
+  int oomScoreAdj = pc->OomScoreAdj();
+
+  RoundOomScoreAdjUpWithLRU(oomScoreAdj, aLRU);
+
+  // We try the newer interface first, and fall back to the older interface
+  // on failure.
+  if (!WriteSysFile(nsPrintfCString("/proc/%d/oom_score_adj", aPid).get(),
+                    nsPrintfCString("%d", oomScoreAdj).get()))
+  {
+    WriteSysFile(nsPrintfCString("/proc/%d/oom_adj", aPid).get(),
+                 nsPrintfCString("%d", OomAdjOfOomScoreAdj(oomScoreAdj)).get());
+  }
+
+  HAL_LOG("Assigning pid %d to cgroup %s", aPid, pc->CGroup().get());
+  pc->AddProcess(aPid);
+}
+
+static bool
+IsValidRealTimePriority(int aValue, int aSchedulePolicy)
+{
+  return (aValue >= sched_get_priority_min(aSchedulePolicy)) &&
+         (aValue <= sched_get_priority_max(aSchedulePolicy));
+}
+
+static void
+SetThreadNiceValue(pid_t aTid, ThreadPriority aThreadPriority, int aValue)
+{
+  MOZ_ASSERT(aThreadPriority < NUM_THREAD_PRIORITY);
+  MOZ_ASSERT(aThreadPriority >= 0);
+
+  HAL_LOG("Setting thread %d to priority level %s; nice level %d",
+          aTid, ThreadPriorityToString(aThreadPriority), aValue);
+  int rv = setpriority(PRIO_PROCESS, aTid, aValue);
+
+  if (rv) {
+    HAL_LOG("Failed to set thread %d to priority level %s; error %s", aTid,
+            ThreadPriorityToString(aThreadPriority), strerror(errno));
+  }
+}
+
+static void
+SetRealTimeThreadPriority(pid_t aTid,
+                          ThreadPriority aThreadPriority,
+                          int aValue)
+{
+  int policy = SCHED_FIFO;
+
+  MOZ_ASSERT(aThreadPriority < NUM_THREAD_PRIORITY);
+  MOZ_ASSERT(aThreadPriority >= 0);
+  MOZ_ASSERT(IsValidRealTimePriority(aValue, policy), "Invalid real time priority");
+
+  // Setting real time priorities requires using sched_setscheduler
+  HAL_LOG("Setting thread %d to priority level %s; Real Time priority %d, "
+          "Schedule FIFO", aTid, ThreadPriorityToString(aThreadPriority),
+          aValue);
+  sched_param schedParam;
+  schedParam.sched_priority = aValue;
+  int rv = sched_setscheduler(aTid, policy, &schedParam);
+
+  if (rv) {
+    HAL_LOG("Failed to set thread %d to real time priority level %s; error %s",
+            aTid, ThreadPriorityToString(aThreadPriority), strerror(errno));
+  }
+}
+
+/*
+ * Used to store the nice value adjustments and real time priorities for the
+ * various thread priority levels.
+ */
+struct ThreadPriorityPrefs {
+  bool initialized;
+  struct {
+    int nice;
+    int realTime;
+  } priorities[NUM_THREAD_PRIORITY];
+};
+
+/*
+ * Reads the preferences for the various process priority levels and sets up
+ * watchers so that if they're dynamically changed the change is reflected on
+ * the appropriate variables.
+ */
+void
+EnsureThreadPriorityPrefs(ThreadPriorityPrefs* prefs)
+{
+  if (prefs->initialized) {
+    return;
+  }
+
+  for (int i = THREAD_PRIORITY_COMPOSITOR; i < NUM_THREAD_PRIORITY; i++) {
+    ThreadPriority priority = static_cast<ThreadPriority>(i);
+
+    // Read the nice values
+    const char* threadPriorityStr = ThreadPriorityToString(priority);
+    nsPrintfCString niceStr("hal.gonk.%s.nice", threadPriorityStr);
+    Preferences::AddIntVarCache(&prefs->priorities[i].nice, niceStr.get());
+
+    // Read the real-time priorities
+    nsPrintfCString realTimeStr("hal.gonk.%s.rt_priority", threadPriorityStr);
+    Preferences::AddIntVarCache(&prefs->priorities[i].realTime,
+                                realTimeStr.get());
+  }
+
+  prefs->initialized = true;
+}
+
+static void
+DoSetThreadPriority(pid_t aTid, hal::ThreadPriority aThreadPriority)
+{
+  // See bug 999115, we can only read preferences on the main thread otherwise
+  // we create a race condition in HAL
+  MOZ_ASSERT(NS_IsMainThread(), "Can only set thread priorities on main thread");
+  MOZ_ASSERT(aThreadPriority >= 0);
+
+  static ThreadPriorityPrefs prefs = { 0 };
+  EnsureThreadPriorityPrefs(&prefs);
+
+  switch (aThreadPriority) {
+    case THREAD_PRIORITY_COMPOSITOR:
+      break;
+    default:
+      HAL_ERR("Unrecognized thread priority %d; Doing nothing",
+              aThreadPriority);
+      return;
+  }
+
+  int realTimePriority = prefs.priorities[aThreadPriority].realTime;
+
+  if (IsValidRealTimePriority(realTimePriority, SCHED_FIFO)) {
+    SetRealTimeThreadPriority(aTid, aThreadPriority, realTimePriority);
+    return;
+  }
+
+  SetThreadNiceValue(aTid, aThreadPriority,
+                     prefs.priorities[aThreadPriority].nice);
+}
+
+namespace {
+
+/**
+ * This class sets the priority of threads given the kernel thread's id and a
+ * value taken from hal::ThreadPriority.
+ *
+ * This runnable must always be dispatched to the main thread otherwise it will fail.
+ * We have to run this from the main thread since preferences can only be read on
+ * main thread.
+ */
+class SetThreadPriorityRunnable : public Runnable
+{
+public:
+  SetThreadPriorityRunnable(pid_t aThreadId, hal::ThreadPriority aThreadPriority)
+    : mThreadId(aThreadId)
+    , mThreadPriority(aThreadPriority)
+  { }
+
+  NS_IMETHOD Run() override
+  {
+    NS_ASSERTION(NS_IsMainThread(), "Can only set thread priorities on main thread");
+    hal_impl::DoSetThreadPriority(mThreadId, mThreadPriority);
+    return NS_OK;
+  }
+
+private:
+  pid_t mThreadId;
+  hal::ThreadPriority mThreadPriority;
+};
+
+} // namespace
+
+void
+SetCurrentThreadPriority(ThreadPriority aThreadPriority)
+{
+  pid_t threadId = gettid();
+  hal_impl::SetThreadPriority(threadId, aThreadPriority);
+}
+
+void
+SetThreadPriority(PlatformThreadId aThreadId,
+                         ThreadPriority aThreadPriority)
+{
+  switch (aThreadPriority) {
+    case THREAD_PRIORITY_COMPOSITOR: {
+      nsCOMPtr<nsIRunnable> runnable =
+        new SetThreadPriorityRunnable(aThreadId, aThreadPriority);
+      NS_DispatchToMainThread(runnable);
+      break;
+    }
+    default:
+      HAL_LOG("Unrecognized thread priority %d; Doing nothing",
+              aThreadPriority);
+      return;
+  }
+}
+
+void
+FactoryReset(FactoryResetReason& aReason)
+{
+  nsCOMPtr<nsIRecoveryService> recoveryService =
+    do_GetService("@mozilla.org/recovery-service;1");
+  if (!recoveryService) {
+    NS_WARNING("Could not get recovery service!");
+    return;
+  }
+
+  if (aReason == FactoryResetReason::Wipe) {
+    recoveryService->FactoryReset("wipe");
+  } else if (aReason == FactoryResetReason::Root) {
+    recoveryService->FactoryReset("root");
+  } else {
+    recoveryService->FactoryReset("normal");
+  }
+}
+
+} // hal_impl
+} // mozilla