gecko-dev/hal/Hal.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set sw=2 ts=8 et ft=cpp : */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "Hal.h"

#include "HalImpl.h"
#include "HalLog.h"
#include "HalSandbox.h"
#include "HalWakeLockInternal.h"
#include "nsIDOMWindow.h"
#include "nsIDocument.h"
#include "nsIDocShell.h"
#include "nsITabChild.h"
#include "nsIWebNavigation.h"
#include "nsThreadUtils.h"
#include "nsXULAppAPI.h"
#include "nsPIDOMWindow.h"
#include "nsJSUtils.h"
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/Observer.h"
#include "mozilla/dom/ContentChild.h"
#include "WindowIdentifier.h"

#ifdef XP_WIN
#include <process.h>
#define getpid _getpid
#endif

using namespace mozilla::services;
using namespace mozilla::dom;

#define PROXY_IF_SANDBOXED(_call)                 \
  do {                                            \
    if (InSandbox()) {                            \
      if (!hal_sandbox::HalChildDestroyed()) {    \
        hal_sandbox::_call;                       \
      }                                           \
    } else {                                      \
      hal_impl::_call;                            \
    }                                             \
  } while (0)

#define RETURN_PROXY_IF_SANDBOXED(_call, defValue)\
  do {                                            \
    if (InSandbox()) {                            \
      if (hal_sandbox::HalChildDestroyed()) {     \
        return defValue;                          \
      }                                           \
      return hal_sandbox::_call;                  \
    } else {                                      \
      return hal_impl::_call;                     \
    }                                             \
  } while (0)

namespace mozilla {
namespace hal {

static bool sInitialized = false;

mozilla::LogModule *
GetHalLog()
{
  static mozilla::LazyLogModule sHalLog("hal");
  return sHalLog;
}

namespace {

void
AssertMainThread()
{
  MOZ_ASSERT(NS_IsMainThread());
}

bool
InSandbox()
{
  return GeckoProcessType_Content == XRE_GetProcessType();
}

bool
WindowIsActive(nsPIDOMWindowInner* aWindow)
{
  nsIDocument* document = aWindow->GetDoc();
  NS_ENSURE_TRUE(document, false);

  return !document->Hidden();
}

StaticAutoPtr<WindowIdentifier::IDArrayType> gLastIDToVibrate;

static void
RecordLastIDToVibrate(const WindowIdentifier& aId)
{
  if (!InSandbox()) {
    *gLastIDToVibrate = aId.AsArray();
  }
}

static bool
MayCancelVibration(const WindowIdentifier& aId)
{
  // Although only active windows may start vibrations, a window may
  // cancel its own vibration even if it's no longer active.
  //
  // After a window is marked as inactive, it sends a CancelVibrate
  // request.  We want this request to cancel a playing vibration
  // started by that window, so we certainly don't want to reject the
  // cancellation request because the window is now inactive.
  //
  // But it could be the case that, after this window became inactive,
  // some other window came along and started a vibration.  We don't
  // want this window's cancellation request to cancel that window's
  // actively-playing vibration!
  //
  // To solve this problem, we keep track of the id of the last window
  // to start a vibration, and only accepts cancellation requests from
  // the same window.  All other cancellation requests are ignored.

  return InSandbox() || (*gLastIDToVibrate == aId.AsArray());
}

} // namespace

void
Vibrate(const nsTArray<uint32_t>& pattern, nsPIDOMWindowInner* window)
{
  Vibrate(pattern, WindowIdentifier(window));
}

void
Vibrate(const nsTArray<uint32_t>& pattern, const WindowIdentifier &id)
{
  AssertMainThread();

  // Only active windows may start vibrations.  If |id| hasn't gone
  // through the IPC layer -- that is, if our caller is the outside
  // world, not hal_proxy -- check whether the window is active.  If
  // |id| has gone through IPC, don't check the window's visibility;
  // only the window corresponding to the bottommost process has its
  // visibility state set correctly.
  if (!id.HasTraveledThroughIPC() && !WindowIsActive(id.GetWindow())) {
    HAL_LOG("Vibrate: Window is inactive, dropping vibrate.");
    return;
  }

  RecordLastIDToVibrate(id);

  // Don't forward our ID if we are not in the sandbox, because hal_impl
  // doesn't need it, and we don't want it to be tempted to read it.  The
  // empty identifier will assert if it's used.
  PROXY_IF_SANDBOXED(Vibrate(pattern, InSandbox() ? id : WindowIdentifier()));
}

void
CancelVibrate(nsPIDOMWindowInner* window)
{
  CancelVibrate(WindowIdentifier(window));
}

void
CancelVibrate(const WindowIdentifier &id)
{
  AssertMainThread();

  if (MayCancelVibration(id)) {
    // Don't forward our ID if we are not in the sandbox, because hal_impl
    // doesn't need it, and we don't want it to be tempted to read it.  The
    // empty identifier will assert if it's used.
    PROXY_IF_SANDBOXED(CancelVibrate(InSandbox() ? id : WindowIdentifier()));
  }
}

template <class InfoType>
class ObserversManager
{
public:
  void AddObserver(Observer<InfoType>* aObserver) {
    mObservers.AddObserver(aObserver);

    if (mObservers.Length() == 1) {
      EnableNotifications();
    }
  }

  void RemoveObserver(Observer<InfoType>* aObserver) {
    bool removed = mObservers.RemoveObserver(aObserver);
    if (!removed) {
      return;
    }

    if (mObservers.Length() == 0) {
      DisableNotifications();
      OnNotificationsDisabled();
    }
  }

  void BroadcastInformation(const InfoType& aInfo) {
    mObservers.Broadcast(aInfo);
  }

protected:
  ~ObserversManager() {
    MOZ_ASSERT(mObservers.Length() == 0);
  }

  virtual void EnableNotifications() = 0;
  virtual void DisableNotifications() = 0;
  virtual void OnNotificationsDisabled() {}

private:
  mozilla::ObserverList<InfoType> mObservers;
};

template <class InfoType>
class CachingObserversManager : public ObserversManager<InfoType>
{
public:
  InfoType GetCurrentInformation() {
    if (mHasValidCache) {
      return mInfo;
    }

    GetCurrentInformationInternal(&mInfo);
    mHasValidCache = true;
    return mInfo;
  }

  void CacheInformation(const InfoType& aInfo) {
    mHasValidCache = true;
    mInfo = aInfo;
  }

  void BroadcastCachedInformation() {
    this->BroadcastInformation(mInfo);
  }

protected:
  virtual void GetCurrentInformationInternal(InfoType*) = 0;

  void OnNotificationsDisabled() override {
    mHasValidCache = false;
  }

private:
  InfoType                mInfo;
  bool                    mHasValidCache;
};

class BatteryObserversManager final
  : public CachingObserversManager<BatteryInformation>
{
protected:
  void EnableNotifications() override {
    PROXY_IF_SANDBOXED(EnableBatteryNotifications());
  }

  void DisableNotifications() override {
    PROXY_IF_SANDBOXED(DisableBatteryNotifications());
  }

  void GetCurrentInformationInternal(BatteryInformation* aInfo) override {
    PROXY_IF_SANDBOXED(GetCurrentBatteryInformation(aInfo));
  }
};

class NetworkObserversManager final
  : public CachingObserversManager<NetworkInformation>
{
protected:
  void EnableNotifications() override {
    PROXY_IF_SANDBOXED(EnableNetworkNotifications());
  }

  void DisableNotifications() override {
    PROXY_IF_SANDBOXED(DisableNetworkNotifications());
  }

  void GetCurrentInformationInternal(NetworkInformation* aInfo) override {
    PROXY_IF_SANDBOXED(GetCurrentNetworkInformation(aInfo));
  }
};

class WakeLockObserversManager final
  : public ObserversManager<WakeLockInformation>
{
protected:
  void EnableNotifications() override {
    PROXY_IF_SANDBOXED(EnableWakeLockNotifications());
  }

  void DisableNotifications() override {
    PROXY_IF_SANDBOXED(DisableWakeLockNotifications());
  }
};

class ScreenConfigurationObserversManager final
  : public CachingObserversManager<ScreenConfiguration>
{
protected:
  void EnableNotifications() override {
    PROXY_IF_SANDBOXED(EnableScreenConfigurationNotifications());
  }

  void DisableNotifications() override {
    PROXY_IF_SANDBOXED(DisableScreenConfigurationNotifications());
  }

  void GetCurrentInformationInternal(ScreenConfiguration* aInfo) override {
    PROXY_IF_SANDBOXED(GetCurrentScreenConfiguration(aInfo));
  }
};

typedef mozilla::ObserverList<SensorData> SensorObserverList;
StaticAutoPtr<SensorObserverList> sSensorObservers[NUM_SENSOR_TYPE];

static SensorObserverList*
GetSensorObservers(SensorType sensor_type) {
  AssertMainThread();
  MOZ_ASSERT(sensor_type < NUM_SENSOR_TYPE);

  if (!sSensorObservers[sensor_type]) {
    sSensorObservers[sensor_type] = new SensorObserverList();
  }

  return sSensorObservers[sensor_type];
}

#define MOZ_IMPL_HAL_OBSERVER(name_)                          \
StaticAutoPtr<name_##ObserversManager> s##name_##Observers;   \
                                                              \
static name_##ObserversManager*                               \
name_##Observers()                                            \
{                                                             \
  AssertMainThread();                                         \
                                                              \
  if (!s##name_##Observers) {                                 \
    MOZ_ASSERT(sInitialized);                                 \
    s##name_##Observers = new name_##ObserversManager();      \
  }                                                           \
                                                              \
  return s##name_##Observers;                                 \
}                                                             \
                                                              \
void                                                          \
Register##name_##Observer(name_##Observer* aObserver)         \
{                                                             \
  AssertMainThread();                                         \
  name_##Observers()->AddObserver(aObserver);                 \
}                                                             \
                                                              \
void                                                          \
Unregister##name_##Observer(name_##Observer* aObserver)       \
{                                                             \
  AssertMainThread();                                         \
  name_##Observers()->RemoveObserver(aObserver);              \
}

MOZ_IMPL_HAL_OBSERVER(Battery)

void
GetCurrentBatteryInformation(BatteryInformation* aInfo)
{
  *aInfo = BatteryObservers()->GetCurrentInformation();
}

void
NotifyBatteryChange(const BatteryInformation& aInfo)
{
  BatteryObservers()->CacheInformation(aInfo);
  BatteryObservers()->BroadcastCachedInformation();
}

void
EnableSensorNotifications(SensorType aSensor) {
  AssertMainThread();
  PROXY_IF_SANDBOXED(EnableSensorNotifications(aSensor));
}

void
DisableSensorNotifications(SensorType aSensor) {
  AssertMainThread();
  PROXY_IF_SANDBOXED(DisableSensorNotifications(aSensor));
}

void
RegisterSensorObserver(SensorType aSensor, ISensorObserver *aObserver) {
  SensorObserverList* observers = GetSensorObservers(aSensor);

  observers->AddObserver(aObserver);
  if (observers->Length() == 1) {
    EnableSensorNotifications(aSensor);
  }
}

void
UnregisterSensorObserver(SensorType aSensor, ISensorObserver *aObserver) {
  SensorObserverList* observers = GetSensorObservers(aSensor);
  if (!observers->RemoveObserver(aObserver) || observers->Length() > 0) {
    return;
  }
  DisableSensorNotifications(aSensor);
}

void
NotifySensorChange(const SensorData &aSensorData) {
  SensorObserverList* observers = GetSensorObservers(aSensorData.sensor());

  observers->Broadcast(aSensorData);
}

MOZ_IMPL_HAL_OBSERVER(Network)

void
GetCurrentNetworkInformation(NetworkInformation* aInfo)
{
  *aInfo = NetworkObservers()->GetCurrentInformation();
}

void
NotifyNetworkChange(const NetworkInformation& aInfo)
{
  NetworkObservers()->CacheInformation(aInfo);
  NetworkObservers()->BroadcastCachedInformation();
}

MOZ_IMPL_HAL_OBSERVER(WakeLock)

void
ModifyWakeLock(const nsAString& aTopic,
               WakeLockControl aLockAdjust,
               WakeLockControl aHiddenAdjust,
               uint64_t aProcessID /* = CONTENT_PROCESS_ID_UNKNOWN */)
{
  AssertMainThread();

  if (aProcessID == CONTENT_PROCESS_ID_UNKNOWN) {
    aProcessID = InSandbox() ? ContentChild::GetSingleton()->GetID() :
                               CONTENT_PROCESS_ID_MAIN;
  }

  PROXY_IF_SANDBOXED(ModifyWakeLock(aTopic, aLockAdjust,
                                    aHiddenAdjust, aProcessID));
}

void
GetWakeLockInfo(const nsAString& aTopic, WakeLockInformation* aWakeLockInfo)
{
  AssertMainThread();
  PROXY_IF_SANDBOXED(GetWakeLockInfo(aTopic, aWakeLockInfo));
}

void
NotifyWakeLockChange(const WakeLockInformation& aInfo)
{
  AssertMainThread();
  WakeLockObservers()->BroadcastInformation(aInfo);
}

MOZ_IMPL_HAL_OBSERVER(ScreenConfiguration)

void
GetCurrentScreenConfiguration(ScreenConfiguration* aScreenConfiguration)
{
  *aScreenConfiguration =
    ScreenConfigurationObservers()->GetCurrentInformation();
}

void
NotifyScreenConfigurationChange(const ScreenConfiguration& aScreenConfiguration)
{
  ScreenConfigurationObservers()->CacheInformation(aScreenConfiguration);
  ScreenConfigurationObservers()->BroadcastCachedInformation();
}

bool
LockScreenOrientation(const ScreenOrientation& aOrientation)
{
  AssertMainThread();
  RETURN_PROXY_IF_SANDBOXED(LockScreenOrientation(aOrientation), false);
}

void
UnlockScreenOrientation()
{
  AssertMainThread();
  PROXY_IF_SANDBOXED(UnlockScreenOrientation());
}

bool
SetProcessPrioritySupported()
{
  RETURN_PROXY_IF_SANDBOXED(SetProcessPrioritySupported(), false);
}

void
SetProcessPriority(int aPid, ProcessPriority aPriority)
{
  // n.b. The sandboxed implementation crashes; SetProcessPriority works only
  // from the main process.
  PROXY_IF_SANDBOXED(SetProcessPriority(aPid, aPriority));
}

// From HalTypes.h.
const char*
ProcessPriorityToString(ProcessPriority aPriority)
{
  switch (aPriority) {
  case PROCESS_PRIORITY_MASTER:
    return "MASTER";
  case PROCESS_PRIORITY_PREALLOC:
    return "PREALLOC";
  case PROCESS_PRIORITY_FOREGROUND_HIGH:
    return "FOREGROUND_HIGH";
  case PROCESS_PRIORITY_FOREGROUND:
    return "FOREGROUND";
  case PROCESS_PRIORITY_FOREGROUND_KEYBOARD:
    return "FOREGROUND_KEYBOARD";
  case PROCESS_PRIORITY_BACKGROUND_PERCEIVABLE:
    return "BACKGROUND_PERCEIVABLE";
  case PROCESS_PRIORITY_BACKGROUND:
    return "BACKGROUND";
  case PROCESS_PRIORITY_UNKNOWN:
    return "UNKNOWN";
  default:
    MOZ_ASSERT(false);
    return "???";
  }
}

void
Init()
{
  MOZ_ASSERT(!sInitialized);

  if (!InSandbox()) {
    gLastIDToVibrate = new WindowIdentifier::IDArrayType();
  }

  WakeLockInit();

  sInitialized = true;
}

void
Shutdown()
{
  MOZ_ASSERT(sInitialized);

  gLastIDToVibrate = nullptr;

  sBatteryObservers = nullptr;
  sNetworkObservers = nullptr;
  sWakeLockObservers = nullptr;
  sScreenConfigurationObservers = nullptr;

  for (auto& sensorObserver : sSensorObservers) {
    sensorObserver = nullptr;
  }

  sInitialized = false;
}

} // namespace hal
} // namespace mozilla