Bug 793105 - Add a "backgroundPerceivable" class for audio-channel-content. r=jlebar,roc

b2g/app/b2g.js

@@ -544,6 +544,8 @@ pref("hal.processPriorityManager.gonk.masterOomScoreAdjust", 0);
 pref("hal.processPriorityManager.gonk.masterKillUnderMB", 1);
 pref("hal.processPriorityManager.gonk.foregroundOomScoreAdjust", 67);
 pref("hal.processPriorityManager.gonk.foregroundKillUnderMB", 4);
+pref("hal.processPriorityManager.gonk.backgroundPerceivableOomScoreAdjust", 134);
+pref("hal.processPriorityManager.gonk.backgroundPerceivebleKillUnderMB", 5);
 pref("hal.processPriorityManager.gonk.backgroundHomescreenOomScoreAdjust", 200);
 pref("hal.processPriorityManager.gonk.backgroundHomescreenKillUnderMB", 5);
 pref("hal.processPriorityManager.gonk.backgroundOomScoreAdjust", 400);

dom/audiochannel/AudioChannelService.cpp

@@ -239,6 +239,12 @@ AudioChannelService::GetMuted(AudioChannelType aType, bool aElementHidden)
   return muted;
 }
 
+bool
+AudioChannelService::ContentChannelIsActive()
+{
+  return mChannelCounters[AUDIO_CHANNEL_CONTENT].Length() > 0;
+}
+
 static PLDHashOperator
 NotifyEnumerator(AudioChannelAgent* aAgent,
                  AudioChannelType aType, void* aData)

dom/audiochannel/AudioChannelService.h

@@ -53,6 +53,12 @@ public:
    */
   virtual bool GetMuted(AudioChannelType aType, bool aElementHidden);
 
+  /**
+   * Return true if there is a content channel active in this process
+   * or one of its subprocesses.
+   */
+  virtual bool ContentChannelIsActive();
+
 protected:
   void Notify();
 

dom/audiochannel/AudioChannelServiceChild.cpp

@@ -12,11 +12,8 @@
 #include "mozilla/StaticPtr.h"
 #include "mozilla/unused.h"
 #include "mozilla/Util.h"
-
 #include "mozilla/dom/ContentChild.h"
-
-#include "base/basictypes.h"
-
+#include "nsIObserverService.h"
 #include "nsThreadUtils.h"
 
 using namespace mozilla;
@@ -82,6 +79,11 @@ AudioChannelServiceChild::RegisterAudioChannelAgent(AudioChannelAgent* aAgent,
   if (cc) {
     cc->SendAudioChannelRegisterType(aType);
   }
+
+  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+  if (obs) {
+    obs->NotifyObservers(nullptr, "audio-channel-agent-changed", nullptr);
+  }
 }
 
 void
@@ -98,5 +100,9 @@ AudioChannelServiceChild::UnregisterAudioChannelAgent(AudioChannelAgent* aAgent)
   if (cc) {
     cc->SendAudioChannelUnregisterType(type);
   }
-}
 
+  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+  if (obs) {
+    obs->NotifyObservers(nullptr, "audio-channel-agent-changed", nullptr);
+  }
+}

dom/ipc/ProcessPriorityManager.cpp

@@ -13,6 +13,7 @@
 #include "mozilla/Services.h"
 #include "mozilla/HalTypes.h"
 #include "mozilla/TimeStamp.h"
+#include "AudioChannelService.h"
 #include "prlog.h"
 #include "nsWeakPtr.h"
 #include "nsXULAppAPI.h"
@@ -80,6 +81,11 @@ GetPPMLog()
 ProcessPriority
 GetBackgroundPriority()
 {
+  AudioChannelService* service = AudioChannelService::GetAudioChannelService();
+  if (service->ContentChannelIsActive()) {
+    return PROCESS_PRIORITY_BACKGROUND_PERCEIVABLE;
+  }
+
   bool isHomescreen = false;
 
   ContentChild* contentChild = ContentChild::GetSingleton();
@@ -101,6 +107,17 @@ GetBackgroundPriority()
          PROCESS_PRIORITY_BACKGROUND;
 }
 
+/**
+ * Determine if the priority is a backround priority.
+ */
+bool
+IsBackgroundPriority(ProcessPriority aPriority)
+{
+  return (aPriority == PROCESS_PRIORITY_BACKGROUND ||
+          aPriority == PROCESS_PRIORITY_BACKGROUND_HOMESCREEN ||
+          aPriority == PROCESS_PRIORITY_BACKGROUND_PERCEIVABLE);
+}
+
 /**
  * This class listens to window creation and visibilitychange events and
  * informs the hal back-end when this process transitions between having no
@@ -135,6 +152,7 @@ public:
 
 private:
   void SetPriority(ProcessPriority aPriority);
+  void OnAudioChannelAgentChanged();
   void OnContentDocumentGlobalCreated(nsISupports* aOuterWindow);
   void OnInnerWindowDestroyed();
   void OnGracePeriodTimerFired();
@@ -170,6 +188,7 @@ ProcessPriorityManager::Init()
   nsCOMPtr<nsIObserverService> os = services::GetObserverService();
   os->AddObserver(this, "content-document-global-created", /* ownsWeak = */ false);
   os->AddObserver(this, "inner-window-destroyed", /* ownsWeak = */ false);
+  os->AddObserver(this, "audio-channel-agent-changed", /* ownsWeak = */ false);
 
   SetPriority(PROCESS_PRIORITY_FOREGROUND);
 }
@@ -186,6 +205,8 @@ ProcessPriorityManager::Observe(
     OnInnerWindowDestroyed();
   } else if (!strcmp(aTopic, "timer-callback")) {
     OnGracePeriodTimerFired();
+  } else if (!strcmp(aTopic, "audio-channel-agent-changed")) {
+    OnAudioChannelAgentChanged();
   } else {
     MOZ_ASSERT(false);
   }
@@ -201,6 +222,14 @@ ProcessPriorityManager::HandleEvent(
   return NS_OK;
 }
 
+void
+ProcessPriorityManager::OnAudioChannelAgentChanged()
+{
+  if (IsBackgroundPriority(mProcessPriority)) {
+    SetPriority(GetBackgroundPriority());
+  }
+}
+
 void
 ProcessPriorityManager::OnContentDocumentGlobalCreated(
   nsISupports* aOuterWindow)
@@ -297,8 +326,7 @@ ProcessPriorityManager::SetPriority(ProcessPriority aPriority)
     return;
   }
 
-  if (aPriority == PROCESS_PRIORITY_BACKGROUND ||
-      aPriority == PROCESS_PRIORITY_BACKGROUND_HOMESCREEN) {
+  if (IsBackgroundPriority(aPriority)) {
     // If this is a foreground --> background transition, give ourselves a
     // grace period before informing hal.
     uint32_t gracePeriodMS = Preferences::GetUint("dom.ipc.processPriorityManager.gracePeriodMS", 1000);
@@ -345,8 +373,7 @@ ProcessPriorityManager::OnGracePeriodTimerFired()
   // mProcessPriority should already be one of the BACKGROUND values: We set it
   // in SetPriority(BACKGROUND), and we canceled this timer if there was an
   // intervening SetPriority(FOREGROUND) call.
-  MOZ_ASSERT(mProcessPriority == PROCESS_PRIORITY_BACKGROUND ||
-             mProcessPriority == PROCESS_PRIORITY_BACKGROUND_HOMESCREEN);
+  MOZ_ASSERT(IsBackgroundPriority(mProcessPriority));
 
   mGracePeriodTimer = nullptr;
   hal::SetProcessPriority(getpid(), mProcessPriority);

hal/HalTypes.h

@@ -70,6 +70,7 @@ typedef Observer<SwitchEvent> SwitchObserver;
 enum ProcessPriority {
   PROCESS_PRIORITY_BACKGROUND,
   PROCESS_PRIORITY_BACKGROUND_HOMESCREEN,
+  PROCESS_PRIORITY_BACKGROUND_PERCEIVABLE,
   // Any priority greater than or equal to FOREGROUND is considered
   // "foreground" for the purposes of priority testing, for example
   // CurrentProcessIsForeground().

hal/gonk/GonkHal.cpp

@@ -1046,8 +1046,13 @@ EnsureKernelLowMemKillerParamsSet()
   nsAutoCString adjParams;
   nsAutoCString minfreeParams;
 
-  const char* priorityClasses[] =
-    {"master", "foreground", "background", "backgroundHomescreen"};
+  const char* priorityClasses[] = {
+    "master",
+    "foreground",
+    "background",
+    "backgroundHomescreen",
+    "backgroundPerceivable"
+  };
   for (size_t i = 0; i < NS_ARRAY_LENGTH(priorityClasses); i++) {
     int32_t oomScoreAdj;
     if (!NS_SUCCEEDED(Preferences::GetInt(nsPrintfCString(
@@ -1112,6 +1117,9 @@ SetProcessPriority(int aPid, ProcessPriority aPriority)
   case PROCESS_PRIORITY_BACKGROUND_HOMESCREEN:
     priorityStr = "backgroundHomescreen";
     break;
+  case PROCESS_PRIORITY_BACKGROUND_PERCEIVABLE:
+    priorityStr = "backgroundPerceivable";
+    break;
   case PROCESS_PRIORITY_FOREGROUND:
     priorityStr = "foreground";
     break;