Fix ownership of CursorWindows across processes.

Bug: 5332296

Ensure that there is always an owner for each CursorWindow
and that references to each window are acquired/released
appropriately at all times.

Added synchronization to CursorToBulkCursorAdaptor to
prevent the underlying Cursor and CursorWindow from being
remotely accessed in ways that might violate invariants,
resulting in leaks or other problems.

Ensured that CursorToBulkCursorAdaptor promptly releases
its references to the Cursor and CursorWindow when closed
so they don't stick around longer than they should, even
if the remote end hangs onto the IBulkCursor for some reason.

CursorWindow respects Parcelable.FLAG_WRITE_RETURN_VALUE
as an indication that one reference to the CursorWindow is
being released.  Correspondingly, CursorToBulkCursorAdaptor
acquires a reference to the CursorWindow before returning
it to the caller.  This change also prevents races from
resulting in the transfer of an invalid CursorWindow over
the wire.

Ensured that BulkCursorToCursorAdaptor promptly releases
its reference to the IBulkCursor when closed and throws
on attempts to access the cursor while closed.

Modified ContentProviderNative to handle both parts of
the wrapping and unwrapping of Cursors into IBulkCursors.
This makes it a lot easier to ensure that the right
things happen on both ends.  Also, it turns out that
the only caller of IContentProvider.bulkQuery was
ContentProviderNative itself so there was no need
to support bulkQuery on ContentProviderProxy and it was
just getting in the way.

Implement CloseGuard on CursorWindow.

Change-Id: Ib3c8305d3cc62322f38a06698d404a2989bb6ef9

1 files changed, 13 insertions, 10 deletions

diff --git a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/android/BridgeContentProvider.java b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/android/BridgeContentProvider.java
index 3835378..c91a3bf 100644
--- a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/android/BridgeContentProvider.java
+++ b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/android/BridgeContentProvider.java
@@ -23,9 +23,6 @@ import android.content.IContentProvider;
 import android.content.OperationApplicationException;
 import android.content.res.AssetFileDescriptor;
 import android.database.Cursor;
-import android.database.CursorWindow;
-import android.database.IBulkCursor;
-import android.database.IContentObserver;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.IBinder;
@@ -41,78 +38,84 @@ import java.util.ArrayList;
  * TODO: never return null when the method is not supposed to. Return fake data instead.
  */
 public final class BridgeContentProvider implements IContentProvider {
-
+    @Override
     public ContentProviderResult[] applyBatch(ArrayList<ContentProviderOperation> arg0)
             throws RemoteException, OperationApplicationException {
         // TODO Auto-generated method stub
         return null;
     }
 
+    @Override
     public int bulkInsert(Uri arg0, ContentValues[] arg1) throws RemoteException {
         // TODO Auto-generated method stub
         return 0;
     }
 
-    public IBulkCursor bulkQuery(Uri arg0, String[] arg1, String arg2, String[] arg3,
-            String arg4, IContentObserver arg5, CursorWindow arg6) throws RemoteException {
-        // TODO Auto-generated method stub
-        return null;
-    }
-
+    @Override
     public Bundle call(String arg0, String arg1, Bundle arg2) throws RemoteException {
         // TODO Auto-generated method stub
         return null;
     }
 
+    @Override
     public int delete(Uri arg0, String arg1, String[] arg2) throws RemoteException {
         // TODO Auto-generated method stub
         return 0;
     }
 
+    @Override
     public String getType(Uri arg0) throws RemoteException {
         // TODO Auto-generated method stub
         return null;
     }
 
+    @Override
     public Uri insert(Uri arg0, ContentValues arg1) throws RemoteException {
         // TODO Auto-generated method stub
         return null;
     }
 
+    @Override
     public AssetFileDescriptor openAssetFile(Uri arg0, String arg1) throws RemoteException,
             FileNotFoundException {
         // TODO Auto-generated method stub
         return null;
     }
 
+    @Override
     public ParcelFileDescriptor openFile(Uri arg0, String arg1) throws RemoteException,
             FileNotFoundException {
         // TODO Auto-generated method stub
         return null;
     }
 
+    @Override
     public Cursor query(Uri arg0, String[] arg1, String arg2, String[] arg3, String arg4)
             throws RemoteException {
         // TODO Auto-generated method stub
         return null;
     }
 
+    @Override
     public int update(Uri arg0, ContentValues arg1, String arg2, String[] arg3)
             throws RemoteException {
         // TODO Auto-generated method stub
         return 0;
     }
 
+    @Override
     public IBinder asBinder() {
         // TODO Auto-generated method stub
         return null;
     }
 
+    @Override
     public String[] getStreamTypes(Uri arg0, String arg1) throws RemoteException {
         // TODO Auto-generated method stub
         return null;
     }
 
+    @Override
     public AssetFileDescriptor openTypedAssetFile(Uri arg0, String arg1, Bundle arg2)
             throws RemoteException, FileNotFoundException {
         // TODO Auto-generated method stub