diff options
Diffstat (limited to 'core/java/android/database/CursorToBulkCursorAdaptor.java')
| -rw-r--r-- | core/java/android/database/CursorToBulkCursorAdaptor.java | 213 |
1 files changed, 159 insertions, 54 deletions
diff --git a/core/java/android/database/CursorToBulkCursorAdaptor.java b/core/java/android/database/CursorToBulkCursorAdaptor.java index 8fa4d3b..a65b3b3 100644 --- a/core/java/android/database/CursorToBulkCursorAdaptor.java +++ b/core/java/android/database/CursorToBulkCursorAdaptor.java @@ -24,19 +24,37 @@ import android.util.Log; /** * Wraps a BulkCursor around an existing Cursor making it remotable. + * <p> + * If the wrapped cursor is a {@link AbstractWindowedCursor} then it owns + * the cursor window. Otherwise, the adaptor takes ownership of the + * cursor itself and ensures it gets closed as needed during deactivation + * and requeries. + * </p> * * {@hide} */ public final class CursorToBulkCursorAdaptor extends BulkCursorNative implements IBinder.DeathRecipient { private static final String TAG = "Cursor"; - private final CrossProcessCursor mCursor; - private CursorWindow mWindow; + + private final Object mLock = new Object(); private final String mProviderName; private ContentObserverProxy mObserver; - private static final class ContentObserverProxy extends ContentObserver - { + /** + * The cursor that is being adapted. + * This field is set to null when the cursor is closed. + */ + private CrossProcessCursor mCursor; + + /** + * The cursor window used by the cross process cursor. + * This field is always null for abstract windowed cursors since they are responsible + * for managing the lifetime of their window. + */ + private CursorWindow mWindowForNonWindowedCursor; + + private static final class ContentObserverProxy extends ContentObserver { protected IContentObserver mRemote; public ContentObserverProxy(IContentObserver remoteObserver, DeathRecipient recipient) { @@ -70,7 +88,7 @@ public final class CursorToBulkCursorAdaptor extends BulkCursorNative } public CursorToBulkCursorAdaptor(Cursor cursor, IContentObserver observer, String providerName, - boolean allowWrite, CursorWindow window) { + CursorWindow window) { try { mCursor = (CrossProcessCursor) cursor; if (mCursor instanceof AbstractWindowedCursor) { @@ -81,90 +99,167 @@ public final class CursorToBulkCursorAdaptor extends BulkCursorNative + providerName, new RuntimeException()); } } - windowedCursor.setWindow(window); + windowedCursor.setWindow(window); // cursor takes ownership of window } else { - mWindow = window; + mWindowForNonWindowedCursor = window; // we own the window mCursor.fillWindow(0, window); } } catch (ClassCastException e) { // TODO Implement this case. + window.close(); throw new UnsupportedOperationException( "Only CrossProcessCursor cursors are supported across process for now", e); } mProviderName = providerName; - createAndRegisterObserverProxy(observer); + synchronized (mLock) { + createAndRegisterObserverProxyLocked(observer); + } } - + + private void closeCursorAndWindowLocked() { + if (mCursor != null) { + unregisterObserverProxyLocked(); + mCursor.close(); + mCursor = null; + } + + if (mWindowForNonWindowedCursor != null) { + mWindowForNonWindowedCursor.close(); + mWindowForNonWindowedCursor = null; + } + } + + private void throwIfCursorIsClosed() { + if (mCursor == null) { + throw new StaleDataException("Attempted to access a cursor after it has been closed."); + } + } + + @Override public void binderDied() { - mCursor.close(); - if (mWindow != null) { - mWindow.close(); + synchronized (mLock) { + closeCursorAndWindowLocked(); } } - + + @Override public CursorWindow getWindow(int startPos) { - mCursor.moveToPosition(startPos); - - if (mWindow != null) { - if (startPos < mWindow.getStartPosition() || - startPos >= (mWindow.getStartPosition() + mWindow.getNumRows())) { - mCursor.fillWindow(startPos, mWindow); - } - return mWindow; - } else { - return ((AbstractWindowedCursor)mCursor).getWindow(); + synchronized (mLock) { + throwIfCursorIsClosed(); + + mCursor.moveToPosition(startPos); + + final CursorWindow window; + if (mCursor instanceof AbstractWindowedCursor) { + window = ((AbstractWindowedCursor)mCursor).getWindow(); + } else { + window = mWindowForNonWindowedCursor; + if (window != null + && (startPos < window.getStartPosition() || + startPos >= (window.getStartPosition() + window.getNumRows()))) { + mCursor.fillWindow(startPos, window); + } + } + + // Acquire a reference before returning from this RPC. + // The Binder proxy will decrement the reference count again as part of writing + // the CursorWindow to the reply parcel as a return value. + if (window != null) { + window.acquireReference(); + } + return window; } } + @Override public void onMove(int position) { - mCursor.onMove(mCursor.getPosition(), position); + synchronized (mLock) { + throwIfCursorIsClosed(); + + mCursor.onMove(mCursor.getPosition(), position); + } } + @Override public int count() { - return mCursor.getCount(); + synchronized (mLock) { + throwIfCursorIsClosed(); + + return mCursor.getCount(); + } } + @Override public String[] getColumnNames() { - return mCursor.getColumnNames(); + synchronized (mLock) { + throwIfCursorIsClosed(); + + return mCursor.getColumnNames(); + } } + @Override public void deactivate() { - maybeUnregisterObserverProxy(); - mCursor.deactivate(); + synchronized (mLock) { + if (mCursor != null) { + unregisterObserverProxyLocked(); + mCursor.deactivate(); + } + } } + @Override public void close() { - maybeUnregisterObserverProxy(); - mCursor.close(); + synchronized (mLock) { + closeCursorAndWindowLocked(); + } } + @Override public int requery(IContentObserver observer, CursorWindow window) { - if (mWindow == null) { - ((AbstractWindowedCursor)mCursor).setWindow(window); - } - try { - if (!mCursor.requery()) { - return -1; + synchronized (mLock) { + throwIfCursorIsClosed(); + + if (mCursor instanceof AbstractWindowedCursor) { + ((AbstractWindowedCursor) mCursor).setWindow(window); + } else { + if (mWindowForNonWindowedCursor != null) { + mWindowForNonWindowedCursor.close(); + } + mWindowForNonWindowedCursor = window; } - } catch (IllegalStateException e) { - IllegalStateException leakProgram = new IllegalStateException( - mProviderName + " Requery misuse db, mCursor isClosed:" + - mCursor.isClosed(), e); - throw leakProgram; - } - - if (mWindow != null) { - mCursor.fillWindow(0, window); - mWindow = window; + + try { + if (!mCursor.requery()) { + return -1; + } + } catch (IllegalStateException e) { + IllegalStateException leakProgram = new IllegalStateException( + mProviderName + " Requery misuse db, mCursor isClosed:" + + mCursor.isClosed(), e); + throw leakProgram; + } + + if (!(mCursor instanceof AbstractWindowedCursor)) { + if (window != null) { + mCursor.fillWindow(0, window); + } + } + + unregisterObserverProxyLocked(); + createAndRegisterObserverProxyLocked(observer); + return mCursor.getCount(); } - maybeUnregisterObserverProxy(); - createAndRegisterObserverProxy(observer); - return mCursor.getCount(); } + @Override public boolean getWantsAllOnMoveCalls() { - return mCursor.getWantsAllOnMoveCalls(); + synchronized (mLock) { + throwIfCursorIsClosed(); + + return mCursor.getWantsAllOnMoveCalls(); + } } /** @@ -173,7 +268,7 @@ public final class CursorToBulkCursorAdaptor extends BulkCursorNative * @param observer the IContentObserver that wants to monitor the cursor * @throws IllegalStateException if an observer is already registered */ - private void createAndRegisterObserverProxy(IContentObserver observer) { + private void createAndRegisterObserverProxyLocked(IContentObserver observer) { if (mObserver != null) { throw new IllegalStateException("an observer is already registered"); } @@ -182,7 +277,7 @@ public final class CursorToBulkCursorAdaptor extends BulkCursorNative } /** Unregister the observer if it is already registered. */ - private void maybeUnregisterObserverProxy() { + private void unregisterObserverProxyLocked() { if (mObserver != null) { mCursor.unregisterContentObserver(mObserver); mObserver.unlinkToDeath(this); @@ -190,11 +285,21 @@ public final class CursorToBulkCursorAdaptor extends BulkCursorNative } } + @Override public Bundle getExtras() { - return mCursor.getExtras(); + synchronized (mLock) { + throwIfCursorIsClosed(); + + return mCursor.getExtras(); + } } + @Override public Bundle respond(Bundle extras) { - return mCursor.respond(extras); + synchronized (mLock) { + throwIfCursorIsClosed(); + + return mCursor.respond(extras); + } } } |