Bug 928558 - AutoMounter mark volumes as shared a bit early when open files are detected. r=qDot

dom/system/gonk/AutoMounter.cpp

@@ -316,11 +316,37 @@ AutoMounterResponseCallback::ResponseReceived(const VolumeCommand* aCommand)
   }
 }
 
+class AutoBool {
+public:
+    explicit AutoBool(bool &aBool) : mBool(aBool) {
+      mBool = true;
+    }
+
+    ~AutoBool() {
+      mBool = false;
+    }
+
+private:
+    bool &mBool;
+};
+
 /***************************************************************************/
 
 void
 AutoMounter::UpdateState()
 {
+  static bool inUpdateState = false;
+  if (inUpdateState) {
+    // When UpdateState calls SetISharing, this causes a volume state
+    // change to occur, which would normally cause UpdateState to be called
+    // again. We want the volume state change to go out (so that device
+    // storage will see the change in sharing state), but since we're
+    // already in UpdateState we just want to prevent recursion from screwing
+    // things up.
+    return;
+  }
+  AutoBool inUpdateStateDetector(inUpdateState);
+
   MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
 
   // If the following preconditions are met:
@@ -379,6 +405,7 @@ AutoMounter::UpdateState()
       umsAvail, umsEnabled, mMode, usbCablePluggedIn, tryToShare);
 
   bool filesOpen = false;
+  static unsigned filesOpenDelayCount = 0;
   VolumeArray::index_type volIndex;
   VolumeArray::size_type  numVolumes = VolumeManager::NumVolumes();
   for (volIndex = 0; volIndex < numVolumes; volIndex++) {
@@ -413,6 +440,12 @@ AutoMounter::UpdateState()
             break;
           }
 
+          // Mark the volume as if we've started sharing. This will cause
+          // apps which watch device storage notifications to see the volume
+          // go into the shared state, and prompt them to close any open files
+          // that they might have.
+          vol->SetIsSharing(true);
+
           // Check to see if there are any open files on the volume and
           // don't initiate the unmount while there are open files.
           OpenFileFinder::Info fileInfo;
@@ -431,15 +464,26 @@ AutoMounter::UpdateState()
             LOGW("UpdateState: Mounted volume %s has open files, not sharing",
                  vol->NameStr());
 
-            // Check again in 5 seconds to see if the files are closed. Since
-            // we're trying to share the volume, this implies that we're
+            // Check again in a few seconds to see if the files are closed.
+            // Since we're trying to share the volume, this implies that we're
             // plugged into the PC via USB and this in turn implies that the
             // battery is charging, so we don't need to be too concerned about
             // wasting battery here.
+            //
+            // If we just detected that there were files open, then we use
+            // a short timer. We will have told the apps that we're trying
+            // trying to share, and they'll be closing their files. This makes
+            // the sharing more responsive. If after a few seconds, the apps
+            // haven't closed their files, then we back off.
+
+            int delay = 1000;
+            if (filesOpenDelayCount > 10) {
+              delay = 5000;
+            }
             MessageLoopForIO::current()->
               PostDelayedTask(FROM_HERE,
                               NewRunnableMethod(this, &AutoMounter::UpdateState),
-                              5000);
+                              delay);
             filesOpen = true;
             break;
           }
@@ -447,7 +491,6 @@ AutoMounter::UpdateState()
           // Volume is mounted, we need to unmount before
           // we can share.
           LOG("UpdateState: Unmounting %s", vol->NameStr());
-          vol->SetIsSharing(true);
           vol->StartUnmount(mResponseCallback);
           return; // UpdateState will be called again when the Unmount command completes
         }
@@ -488,8 +531,10 @@ AutoMounter::UpdateState()
 
   int32_t status = AUTOMOUNTER_STATUS_DISABLED;
   if (filesOpen) {
+    filesOpenDelayCount++;
     status = AUTOMOUNTER_STATUS_FILES_OPEN;
   } else if (enabled) {
+    filesOpenDelayCount = 0;
     status = AUTOMOUNTER_STATUS_ENABLED;
   }
   SetAutoMounterStatus(status);

dom/system/gonk/Volume.cpp

@@ -68,7 +68,15 @@ Volume::Volume(const nsCSubstring& aName)
 void
 Volume::SetIsSharing(bool aIsSharing)
 {
+  if (aIsSharing == mIsSharing) {
+    return;
+  }
   mIsSharing = aIsSharing;
+  LOG("Volume %s: IsSharing set to %d state %s",
+      NameStr(), (int)mIsSharing, StateStr(mState));
+  if (mIsSharing) {
+    mEventObserverList.Broadcast(this);
+  }
 }
 
 void

dom/system/gonk/nsVolume.cpp

@@ -95,6 +95,12 @@ bool nsVolume::Equals(nsIVolume* aVolume)
     return false;
   }
 
+  bool isSharing;
+  aVolume->GetIsSharing(&isSharing);
+  if (mIsSharing != isSharing) {
+    return false;
+  }
+
   return true;
 }
 

dom/system/gonk/nsVolume.h

@@ -71,6 +71,10 @@ public:
   int32_t State() const               { return mState; }
   const char* StateStr() const        { return NS_VolumeStateStr(mState); }
 
+  bool IsFake() const                 { return mIsFake; }
+  bool IsMediaPresent() const         { return mIsMediaPresent; }
+  bool IsSharing() const              { return mIsSharing; }
+
   typedef nsTArray<nsRefPtr<nsVolume> > Array;
 
 private:
@@ -80,9 +84,6 @@ private:
   void UpdateMountLock(const nsAString& aMountLockState);
   void UpdateMountLock(bool aMountLocked);
 
-  bool IsFake() const                 { return mIsFake; }
-  bool IsMediaPresent() const         { return mIsMediaPresent; }
-  bool IsSharing() const              { return mIsSharing; }
   void SetIsFake(bool aIsFake);
   void SetState(int32_t aState);
 

dom/system/gonk/nsVolumeService.cpp

@@ -454,7 +454,7 @@ nsVolumeService::UpdateVolumeIOThread(const Volume* aVolume)
       "media %d sharing %d",
       aVolume->NameStr(), aVolume->StateStr(), aVolume->MountPoint().get(),
       aVolume->MountGeneration(), (int)aVolume->IsMountLocked(),
-      (int)aVolume->IsMediaPresent(), (int)aVolume->IsSharing());
+      (int)aVolume->MediaPresent(), (int)aVolume->IsSharing());
   MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
   NS_DispatchToMainThread(new UpdateVolumeRunnable(this, aVolume));
 }