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

2 files changed, 13 insertions, 35 deletions

diff --git a/test-runner/src/android/test/mock/MockContentProvider.java b/test-runner/src/android/test/mock/MockContentProvider.java
index b63ff3d..e0ce322 100644
--- a/test-runner/src/android/test/mock/MockContentProvider.java
+++ b/test-runner/src/android/test/mock/MockContentProvider.java
@@ -21,16 +21,12 @@ import android.content.ContentProviderOperation;
 import android.content.ContentProviderResult;
 import android.content.ContentValues;
 import android.content.Context;
-import android.content.EntityIterator;
 import android.content.IContentProvider;
 import android.content.OperationApplicationException;
 import android.content.pm.PathPermission;
 import android.content.pm.ProviderInfo;
 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;
@@ -55,84 +51,75 @@ public class MockContentProvider extends ContentProvider {
      * IContentProvider that directs all calls to this MockContentProvider.
      */
     private class InversionIContentProvider implements IContentProvider {
-        @SuppressWarnings("unused")
+        @Override
         public ContentProviderResult[] applyBatch(ArrayList<ContentProviderOperation> operations)
                 throws RemoteException, OperationApplicationException {
             return MockContentProvider.this.applyBatch(operations);
         }
 
-        @SuppressWarnings("unused")
+        @Override
         public int bulkInsert(Uri url, ContentValues[] initialValues) throws RemoteException {
             return MockContentProvider.this.bulkInsert(url, initialValues);
         }
 
-        @SuppressWarnings("unused")
-        public IBulkCursor bulkQuery(Uri url, String[] projection, String selection,
-                String[] selectionArgs, String sortOrder, IContentObserver observer,
-                CursorWindow window) throws RemoteException {
-            throw new UnsupportedOperationException("Must not come here");
-        }
-
-        @SuppressWarnings("unused")
+        @Override
         public int delete(Uri url, String selection, String[] selectionArgs)
                 throws RemoteException {
             return MockContentProvider.this.delete(url, selection, selectionArgs);
         }
 
-        @SuppressWarnings("unused")
+        @Override
         public String getType(Uri url) throws RemoteException {
             return MockContentProvider.this.getType(url);
         }
 
-        @SuppressWarnings("unused")
+        @Override
         public Uri insert(Uri url, ContentValues initialValues) throws RemoteException {
             return MockContentProvider.this.insert(url, initialValues);
         }
 
-        @SuppressWarnings("unused")
+        @Override
         public AssetFileDescriptor openAssetFile(Uri url, String mode) throws RemoteException,
                 FileNotFoundException {
             return MockContentProvider.this.openAssetFile(url, mode);
         }
 
-        @SuppressWarnings("unused")
+        @Override
         public ParcelFileDescriptor openFile(Uri url, String mode) throws RemoteException,
                 FileNotFoundException {
             return MockContentProvider.this.openFile(url, mode);
         }
 
-        @SuppressWarnings("unused")
+        @Override
         public Cursor query(Uri url, String[] projection, String selection, String[] selectionArgs,
                 String sortOrder) throws RemoteException {
             return MockContentProvider.this.query(url, projection, selection,
                     selectionArgs, sortOrder);
         }
 
-        @SuppressWarnings("unused")
+        @Override
         public int update(Uri url, ContentValues values, String selection, String[] selectionArgs)
                 throws RemoteException {
             return MockContentProvider.this.update(url, values, selection, selectionArgs);
         }
 
-        /**
-         * @hide
-         */
-        @SuppressWarnings("unused")
+        @Override
         public Bundle call(String method, String request, Bundle args)
                 throws RemoteException {
             return MockContentProvider.this.call(method, request, args);
         }
 
+        @Override
         public IBinder asBinder() {
             throw new UnsupportedOperationException();
         }
 
-        @SuppressWarnings("unused")
+        @Override
         public String[] getStreamTypes(Uri url, String mimeTypeFilter) throws RemoteException {
             return MockContentProvider.this.getStreamTypes(url, mimeTypeFilter);
         }
 
-        @SuppressWarnings("unused")
+        @Override
         public AssetFileDescriptor openTypedAssetFile(Uri url, String mimeType, Bundle opts)
                 throws RemoteException, FileNotFoundException {
             return MockContentProvider.this.openTypedAssetFile(url, mimeType, opts);
diff --git a/test-runner/src/android/test/mock/MockIContentProvider.java b/test-runner/src/android/test/mock/MockIContentProvider.java
index 183be41..b7733a4 100644
--- a/test-runner/src/android/test/mock/MockIContentProvider.java
+++ b/test-runner/src/android/test/mock/MockIContentProvider.java
@@ -23,9 +23,6 @@ import android.content.EntityIterator;
 import android.content.IContentProvider;
 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;
@@ -47,12 +44,6 @@ public class MockIContentProvider implements IContentProvider {
         throw new UnsupportedOperationException("unimplemented mock method");
     }
 
-    public IBulkCursor bulkQuery(Uri url, String[] projection, String selection,
-            String[] selectionArgs, String sortOrder, IContentObserver observer,
-            CursorWindow window) {
-        throw new UnsupportedOperationException("unimplemented mock method");
-    }
-
     @SuppressWarnings("unused")
     public int delete(Uri url, String selection, String[] selectionArgs)
             throws RemoteException {