Bug 847255 - [Bluetooth/AudioChannel] A2DP failed to start session due to music resume too fast during SCO is disconnecting. r=baku

dom/audiochannel/AudioChannelService.cpp

@@ -63,7 +63,7 @@ AudioChannelService::Shutdown()
   }
 }
 
-NS_IMPL_ISUPPORTS0(AudioChannelService)
+NS_IMPL_ISUPPORTS2(AudioChannelService, nsIObserver, nsITimerCallback)
 
 AudioChannelService::AudioChannelService()
 : mCurrentHigherChannel(AUDIO_CHANNEL_LAST)
@@ -102,9 +102,17 @@ AudioChannelService::RegisterType(AudioChannelType aType, uint64_t aChildID)
   AudioChannelInternalType type = GetInternalType(aType, true);
   mChannelCounters[type].AppendElement(aChildID);
 
-  // In order to avoid race conditions, it's safer to notify any existing
-  // agent any time a new one is registered.
   if (XRE_GetProcessType() == GeckoProcessType_Default) {
+    // Since there is another telephony registered, we can unregister old one
+    // immediately.
+    if (mDeferTelChannelTimer && aType == AUDIO_CHANNEL_TELEPHONY) {
+      mDeferTelChannelTimer->Cancel();
+      mDeferTelChannelTimer = nullptr;
+      UnregisterTypeInternal(aType, mTimerElementHidden, mTimerChildID);
+    }
+
+    // In order to avoid race conditions, it's safer to notify any existing
+    // agent any time a new one is registered.
     SendAudioChannelChangedNotification(aChildID);
     Notify();
   }
@@ -125,6 +133,28 @@ void
 AudioChannelService::UnregisterType(AudioChannelType aType,
                                     bool aElementHidden,
                                     uint64_t aChildID)
+{
+  // There are two reasons to defer the decrease of telephony channel.
+  // 1. User can have time to remove device from his ear before music resuming.
+  // 2. Give BT SCO to be disconnected before starting to connect A2DP.
+  if (XRE_GetProcessType() == GeckoProcessType_Default &&
+      aType == AUDIO_CHANNEL_TELEPHONY &&
+      (mChannelCounters[AUDIO_CHANNEL_INT_TELEPHONY_HIDDEN].Length() +
+       mChannelCounters[AUDIO_CHANNEL_INT_TELEPHONY].Length()) == 1) {
+    mTimerElementHidden = aElementHidden;
+    mTimerChildID = aChildID;
+    mDeferTelChannelTimer = do_CreateInstance("@mozilla.org/timer;1");
+    mDeferTelChannelTimer->InitWithCallback(this, 1500, nsITimer::TYPE_ONE_SHOT);
+    return;
+  }
+
+  UnregisterTypeInternal(aType, aElementHidden, aChildID);
+}
+
+void
+AudioChannelService::UnregisterTypeInternal(AudioChannelType aType,
+                                            bool aElementHidden,
+                                            uint64_t aChildID)
 {
   // The array may contain multiple occurrence of this appId but
   // this should remove only the first one.
@@ -400,6 +430,14 @@ AudioChannelService::Notify()
   }
 }
 
+NS_IMETHODIMP
+AudioChannelService::Notify(nsITimer* aTimer)
+{
+  UnregisterTypeInternal(AUDIO_CHANNEL_TELEPHONY, mTimerElementHidden, mTimerChildID);
+  mDeferTelChannelTimer = nullptr;
+  return NS_OK;
+}
+
 bool
 AudioChannelService::ChannelsActiveWithHigherPriorityThan(AudioChannelInternalType aType)
 {

dom/audiochannel/AudioChannelService.h

@@ -10,6 +10,7 @@
 #include "nsAutoPtr.h"
 #include "nsIObserver.h"
 #include "nsTArray.h"
+#include "nsITimer.h"
 
 #include "AudioChannelCommon.h"
 #include "AudioChannelAgent.h"
@@ -18,11 +19,14 @@
 namespace mozilla {
 namespace dom {
 
-class AudioChannelService : public nsIObserver
+class AudioChannelService
+: public nsIObserver
+, public nsITimerCallback
 {
 public:
   NS_DECL_ISUPPORTS
   NS_DECL_NSIOBSERVER
+  NS_DECL_NSITIMERCALLBACK
 
   /**
    * Returns the AudioChannelServce singleton. Only to be called from main thread.
@@ -79,6 +83,8 @@ protected:
   void RegisterType(AudioChannelType aType, uint64_t aChildID);
   void UnregisterType(AudioChannelType aType, bool aElementHidden,
                       uint64_t aChildID);
+  void UnregisterTypeInternal(AudioChannelType aType, bool aElementHidden,
+                              uint64_t aChildID);
 
   bool GetMutedInternal(AudioChannelType aType, uint64_t aChildID,
                         bool aElementHidden, bool aElementWasHidden);
@@ -144,6 +150,10 @@ protected:
   nsTArray<uint64_t> mActiveContentChildIDs;
   bool mActiveContentChildIDsFrozen;
 
+  nsCOMPtr<nsITimer> mDeferTelChannelTimer;
+  bool mTimerElementHidden;
+  uint64_t mTimerChildID;
+
   // This is needed for IPC comunication between
   // AudioChannelServiceChild and this class.
   friend class ContentParent;