Prevent accessing LauncherModel data structures on main thread. (5220358)

Change-Id: Ib9de96abb0ab13ef63b9c594f6982368fd1b614f

2 files changed, 37 insertions, 11 deletions

diff --git a/src/com/android/launcher2/Launcher.java b/src/com/android/launcher2/Launcher.java
index 637d95607..8bbf902b3 100644
--- a/src/com/android/launcher2/Launcher.java
+++ b/src/com/android/launcher2/Launcher.java
@@ -1602,7 +1602,9 @@ public final class Launcher extends Activity
      * leak the previous Home screen on orientation change.
      */
     private void unbindWorkspaceAndHotseatItems() {
-        LauncherModel.unbindWorkspaceItems();
+        if (mModel != null) {
+            mModel.unbindWorkspaceItems();
+        }
     }
 
     /**
@@ -2754,9 +2756,6 @@ public final class Launcher extends Activity
         if (mHotseat != null) {
             mHotseat.resetLayout();
         }
-
-        // This wasn't being called before which resulted in a leak of AppWidgetHostViews
-        unbindWorkspaceAndHotseatItems();
     }
 
     /**
diff --git a/src/com/android/launcher2/LauncherModel.java b/src/com/android/launcher2/LauncherModel.java
index 239970e84..ad75798f2 100644
--- a/src/com/android/launcher2/LauncherModel.java
+++ b/src/com/android/launcher2/LauncherModel.java
@@ -155,10 +155,31 @@ public class LauncherModel extends BroadcastReceiver {
         return Bitmap.createBitmap(mDefaultIcon);
     }
 
-    public static void unbindWorkspaceItems() {
-        for (ItemInfo item: sWorkspaceItems) {
-            item.unbind();
-        }
+    public void unbindWorkspaceItems() {
+        sWorker.post(new Runnable() {
+            @Override
+            public void run() {
+                unbindWorkspaceItemsOnMainThread();
+            }
+        });
+    }
+
+    /** Unbinds all the sWorkspaceItems on the main thread, and return a copy of sWorkspaceItems
+     * that is save to reference from the main thread. */
+    private ArrayList<ItemInfo> unbindWorkspaceItemsOnMainThread() {
+        // Ensure that we don't use the same workspace items data structure on the main thread
+        // by making a copy of workspace items first.
+        final ArrayList<ItemInfo> workspaceItems = new ArrayList<ItemInfo>(sWorkspaceItems);
+        mHandler.post(new Runnable() {
+           @Override
+            public void run() {
+               for (ItemInfo item : workspaceItems) {
+                   item.unbind();
+               }
+            }
+        });
+
+        return workspaceItems;
     }
 
     /**
@@ -1165,8 +1186,12 @@ public class LauncherModel extends BroadcastReceiver {
                     }
                 }
             });
+
+            // Unbind previously bound workspace items to prevent a leak of AppWidgetHostViews.
+            final ArrayList<ItemInfo> workspaceItems = unbindWorkspaceItemsOnMainThread();
+
             // Add the items to the workspace.
-            N = sWorkspaceItems.size();
+            N = workspaceItems.size();
             for (int i=0; i<N; i+=ITEMS_CHUNK) {
                 final int start = i;
                 final int chunkSize = (i+ITEMS_CHUNK <= N) ? ITEMS_CHUNK : (N-i);
@@ -1174,16 +1199,18 @@ public class LauncherModel extends BroadcastReceiver {
                     public void run() {
                         Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                         if (callbacks != null) {
-                            callbacks.bindItems(sWorkspaceItems, start, start+chunkSize);
+                            callbacks.bindItems(workspaceItems, start, start+chunkSize);
                         }
                     }
                 });
             }
+            // Ensure that we don't use the same folders data structure on the main thread
+            final HashMap<Long, FolderInfo> folders = new HashMap<Long, FolderInfo>(sFolders);
             mHandler.post(new Runnable() {
                 public void run() {
                     Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                     if (callbacks != null) {
-                        callbacks.bindFolders(sFolders);
+                        callbacks.bindFolders(folders);
                     }
                 }
             });