diff --git a/src/com/fsck/k9/provider/MessageProvider.java b/src/com/fsck/k9/provider/MessageProvider.java
index c342d5e3d..7ef4ea934 100644
--- a/src/com/fsck/k9/provider/MessageProvider.java
+++ b/src/com/fsck/k9/provider/MessageProvider.java
@@ -84,7 +84,7 @@ public class MessageProvider extends ContentProvider
String INCREMENT = "id";
}
- protected interface QueryHandler
+ protected static interface QueryHandler
{
/**
* The path this instance is able to respond to.
@@ -451,272 +451,359 @@ public class MessageProvider extends ContentProvider
}
}
- protected class ThrottlingQueryHandler implements QueryHandler
+ /**
+ * Cursor wrapper that release a semaphore on close. Close is also triggered
+ * on {@link #finalize()}.
+ */
+ protected static class MonitoredCursor implements CrossProcessCursor
{
+ /**
+ * The underlying cursor implementation that handles regular
+ * requests
+ */
+ private CrossProcessCursor mCursor;
- protected final class MonitoredCursor implements CrossProcessCursor
+ /**
+ * Whether {@link #close()} was invoked
+ */
+ private AtomicBoolean mClosed = new AtomicBoolean(false);
+
+ private Semaphore mSemaphore;
+
+ /**
+ * @param cursor
+ * Never null.
+ * @param semaphore
+ * The semaphore to release on close. Never
+ * null.
+ */
+ protected MonitoredCursor(final CrossProcessCursor cursor, final Semaphore semaphore)
{
- private CrossProcessCursor mCursor;
+ this.mCursor = cursor;
+ this.mSemaphore = semaphore;
+ }
- @Override
- public void close()
+ /* (non-Javadoc)
+ *
+ * Close the underlying cursor and dereference it.
+ *
+ * @see android.database.Cursor#close()
+ */
+ @Override
+ public void close()
+ {
+ if (mClosed.compareAndSet(false, true))
{
mCursor.close();
- if (mClosed.compareAndSet(false, true))
- {
- Log.d(K9.LOG_TAG, "Cursor closed, releasing semaphore");
- mSemaphore.release();
- }
- }
-
- @Override
- public void fillWindow(int pos, CursorWindow winow)
- {
- mCursor.fillWindow(pos, winow);
- }
-
- @Override
- public CursorWindow getWindow()
- {
- return mCursor.getWindow();
- }
-
- @Override
- public boolean onMove(int oldPosition, int newPosition)
- {
- return mCursor.onMove(oldPosition, newPosition);
- }
-
- private AtomicBoolean mClosed = new AtomicBoolean(false);
-
-
- protected MonitoredCursor(final CrossProcessCursor cursor)
- {
- this.mCursor = cursor;
- }
-
- @Override
- public void copyStringToBuffer(int columnIndex, CharArrayBuffer buffer)
- {
- mCursor.copyStringToBuffer(columnIndex, buffer);
- }
-
- @Override
- public void deactivate()
- {
- mCursor.deactivate();
- }
-
- @Override
- public byte[] getBlob(int columnIndex)
- {
- return mCursor.getBlob(columnIndex);
- }
-
- @Override
- public int getColumnCount()
- {
- return mCursor.getColumnCount();
- }
-
- @Override
- public int getColumnIndex(String columnName)
- {
- return mCursor.getColumnIndex(columnName);
- }
-
- @Override
- public int getColumnIndexOrThrow(String columnName) throws IllegalArgumentException
- {
- return mCursor.getColumnIndexOrThrow(columnName);
- }
-
- @Override
- public String getColumnName(int columnIndex)
- {
- return mCursor.getColumnName(columnIndex);
- }
-
- @Override
- public String[] getColumnNames()
- {
- return mCursor.getColumnNames();
- }
-
- @Override
- public int getCount()
- {
- return mCursor.getCount();
- }
-
- @Override
- public double getDouble(int columnIndex)
- {
- return mCursor.getDouble(columnIndex);
- }
-
- @Override
- public Bundle getExtras()
- {
- return mCursor.getExtras();
- }
-
- @Override
- public float getFloat(int columnIndex)
- {
- return mCursor.getFloat(columnIndex);
- }
-
- @Override
- public int getInt(int columnIndex)
- {
- return mCursor.getInt(columnIndex);
- }
-
- @Override
- public long getLong(int columnIndex)
- {
- return mCursor.getLong(columnIndex);
- }
-
- @Override
- public int getPosition()
- {
- return mCursor.getPosition();
- }
-
- @Override
- public short getShort(int columnIndex)
- {
- return mCursor.getShort(columnIndex);
- }
-
- @Override
- public String getString(int columnIndex)
- {
- return mCursor.getString(columnIndex);
- }
-
- @Override
- public boolean getWantsAllOnMoveCalls()
- {
- return mCursor.getWantsAllOnMoveCalls();
- }
-
- @Override
- public boolean isAfterLast()
- {
- return mCursor.isAfterLast();
- }
-
- @Override
- public boolean isBeforeFirst()
- {
- return mCursor.isBeforeFirst();
- }
-
- @Override
- public boolean isClosed()
- {
- return mCursor.isClosed();
- }
-
- @Override
- public boolean isFirst()
- {
- return mCursor.isFirst();
- }
-
- public boolean isLast()
- {
- return mCursor.isLast();
- }
-
- @Override
- public boolean isNull(int columnIndex)
- {
- return mCursor.isNull(columnIndex);
- }
-
- @Override
- public boolean move(int offset)
- {
- return mCursor.move(offset);
- }
-
- @Override
- public boolean moveToFirst()
- {
- return mCursor.moveToFirst();
- }
-
- @Override
- public boolean moveToLast()
- {
- return mCursor.moveToLast();
- }
-
- @Override
- public boolean moveToNext()
- {
- return mCursor.moveToNext();
- }
-
- @Override
- public boolean moveToPosition(int position)
- {
- return mCursor.moveToPosition(position);
- }
-
- @Override
- public boolean moveToPrevious()
- {
- return mCursor.moveToPrevious();
- }
-
- @Override
- public void registerContentObserver(ContentObserver observer)
- {
- mCursor.registerContentObserver(observer);
- }
-
- @Override
- public void registerDataSetObserver(DataSetObserver observer)
- {
- mCursor.registerDataSetObserver(observer);
- }
-
- @Override
- public boolean requery()
- {
- return mCursor.requery();
- }
-
- @Override
- public Bundle respond(Bundle extras)
- {
- return mCursor.respond(extras);
- }
-
- @Override
- public void setNotificationUri(ContentResolver cr, Uri uri)
- {
- mCursor.setNotificationUri(cr, uri);
- }
-
- @Override
- public void unregisterContentObserver(ContentObserver observer)
- {
- mCursor.unregisterContentObserver(observer);
- }
-
- @Override
- public void unregisterDataSetObserver(DataSetObserver observer)
- {
- mCursor.unregisterDataSetObserver(observer);
+ Log.d(K9.LOG_TAG, "Cursor closed, null'ing & releasing semaphore");
+ mCursor = null;
+ mSemaphore.release();
}
}
+ @Override
+ public boolean isClosed()
+ {
+ return mClosed.get() || mCursor.isClosed();
+ }
+
+ /* (non-Javadoc)
+ *
+ * Making sure cursor gets closed on garbage collection
+ *
+ * @see java.lang.Object#finalize()
+ */
+ @Override
+ protected void finalize() throws Throwable
+ {
+ close();
+ super.finalize();
+ }
+
+ protected void checkClosed() throws IllegalStateException
+ {
+ if (mClosed.get())
+ {
+ throw new IllegalStateException("Cursor was closed");
+ }
+ }
+
+ @Override
+ public void fillWindow(int pos, CursorWindow winow)
+ {
+ checkClosed();
+ mCursor.fillWindow(pos, winow);
+ }
+
+ @Override
+ public CursorWindow getWindow()
+ {
+ checkClosed();
+ return mCursor.getWindow();
+ }
+
+ @Override
+ public boolean onMove(int oldPosition, int newPosition)
+ {
+ checkClosed();
+ return mCursor.onMove(oldPosition, newPosition);
+ }
+
+ @Override
+ public void copyStringToBuffer(int columnIndex, CharArrayBuffer buffer)
+ {
+ checkClosed();
+ mCursor.copyStringToBuffer(columnIndex, buffer);
+ }
+
+ @Override
+ public void deactivate()
+ {
+ checkClosed();
+ mCursor.deactivate();
+ }
+
+ @Override
+ public byte[] getBlob(int columnIndex)
+ {
+ checkClosed();
+ return mCursor.getBlob(columnIndex);
+ }
+
+ @Override
+ public int getColumnCount()
+ {
+ checkClosed();
+ return mCursor.getColumnCount();
+ }
+
+ @Override
+ public int getColumnIndex(String columnName)
+ {
+ checkClosed();
+ return mCursor.getColumnIndex(columnName);
+ }
+
+ @Override
+ public int getColumnIndexOrThrow(String columnName) throws IllegalArgumentException
+ {
+ checkClosed();
+ return mCursor.getColumnIndexOrThrow(columnName);
+ }
+
+ @Override
+ public String getColumnName(int columnIndex)
+ {
+ checkClosed();
+ return mCursor.getColumnName(columnIndex);
+ }
+
+ @Override
+ public String[] getColumnNames()
+ {
+ checkClosed();
+ return mCursor.getColumnNames();
+ }
+
+ @Override
+ public int getCount()
+ {
+ checkClosed();
+ return mCursor.getCount();
+ }
+
+ @Override
+ public double getDouble(int columnIndex)
+ {
+ checkClosed();
+ return mCursor.getDouble(columnIndex);
+ }
+
+ @Override
+ public Bundle getExtras()
+ {
+ checkClosed();
+ return mCursor.getExtras();
+ }
+
+ @Override
+ public float getFloat(int columnIndex)
+ {
+ checkClosed();
+ return mCursor.getFloat(columnIndex);
+ }
+
+ @Override
+ public int getInt(int columnIndex)
+ {
+ checkClosed();
+ return mCursor.getInt(columnIndex);
+ }
+
+ @Override
+ public long getLong(int columnIndex)
+ {
+ checkClosed();
+ return mCursor.getLong(columnIndex);
+ }
+
+ @Override
+ public int getPosition()
+ {
+ checkClosed();
+ return mCursor.getPosition();
+ }
+
+ @Override
+ public short getShort(int columnIndex)
+ {
+ checkClosed();
+ return mCursor.getShort(columnIndex);
+ }
+
+ @Override
+ public String getString(int columnIndex)
+ {
+ checkClosed();
+ return mCursor.getString(columnIndex);
+ }
+
+ @Override
+ public boolean getWantsAllOnMoveCalls()
+ {
+ checkClosed();
+ return mCursor.getWantsAllOnMoveCalls();
+ }
+
+ @Override
+ public boolean isAfterLast()
+ {
+ checkClosed();
+ return mCursor.isAfterLast();
+ }
+
+ @Override
+ public boolean isBeforeFirst()
+ {
+ checkClosed();
+ return mCursor.isBeforeFirst();
+ }
+
+ @Override
+ public boolean isFirst()
+ {
+ checkClosed();
+ return mCursor.isFirst();
+ }
+
+ public boolean isLast()
+ {
+ checkClosed();
+ return mCursor.isLast();
+ }
+
+ @Override
+ public boolean isNull(int columnIndex)
+ {
+ checkClosed();
+ return mCursor.isNull(columnIndex);
+ }
+
+ @Override
+ public boolean move(int offset)
+ {
+ checkClosed();
+ return mCursor.move(offset);
+ }
+
+ @Override
+ public boolean moveToFirst()
+ {
+ checkClosed();
+ return mCursor.moveToFirst();
+ }
+
+ @Override
+ public boolean moveToLast()
+ {
+ checkClosed();
+ return mCursor.moveToLast();
+ }
+
+ @Override
+ public boolean moveToNext()
+ {
+ checkClosed();
+ return mCursor.moveToNext();
+ }
+
+ @Override
+ public boolean moveToPosition(int position)
+ {
+ checkClosed();
+ return mCursor.moveToPosition(position);
+ }
+
+ @Override
+ public boolean moveToPrevious()
+ {
+ checkClosed();
+ return mCursor.moveToPrevious();
+ }
+
+ @Override
+ public void registerContentObserver(ContentObserver observer)
+ {
+ checkClosed();
+ mCursor.registerContentObserver(observer);
+ }
+
+ @Override
+ public void registerDataSetObserver(DataSetObserver observer)
+ {
+ checkClosed();
+ mCursor.registerDataSetObserver(observer);
+ }
+
+ @Override
+ public boolean requery()
+ {
+ checkClosed();
+ return mCursor.requery();
+ }
+
+ @Override
+ public Bundle respond(Bundle extras)
+ {
+ checkClosed();
+ return mCursor.respond(extras);
+ }
+
+ @Override
+ public void setNotificationUri(ContentResolver cr, Uri uri)
+ {
+ checkClosed();
+ mCursor.setNotificationUri(cr, uri);
+ }
+
+ @Override
+ public void unregisterContentObserver(ContentObserver observer)
+ {
+ checkClosed();
+ mCursor.unregisterContentObserver(observer);
+ }
+
+ @Override
+ public void unregisterDataSetObserver(DataSetObserver observer)
+ {
+ checkClosed();
+ mCursor.unregisterDataSetObserver(observer);
+ }
+ }
+
+ protected class ThrottlingQueryHandler implements QueryHandler
+ {
+
private QueryHandler mDelegate;
public ThrottlingQueryHandler(final QueryHandler delegate)
@@ -740,12 +827,13 @@ public class MessageProvider extends ContentProvider
cursor = mDelegate.query(uri, projection, selection, selectionArgs, sortOrder);
/* Android content resolvers can only process CrossProcessCursor instances */
- if (cursor == null || !(cursor instanceof CrossProcessCursor))
+ if (!(cursor instanceof CrossProcessCursor))
{
+ Log.w(K9.LOG_TAG, "Unsupported cursor, returning null: " + cursor);
return null;
}
- final MonitoredCursor wrapped = new MonitoredCursor((CrossProcessCursor) cursor);
+ final MonitoredCursor wrapped = new MonitoredCursor((CrossProcessCursor) cursor, mSemaphore);
/* use a weak reference not to actively prevent garbage collection */
final WeakReference weakReference = new WeakReference(wrapped);
@@ -758,7 +846,7 @@ public class MessageProvider extends ContentProvider
public void run()
{
final MonitoredCursor monitored = weakReference.get();
- if (monitored != null && monitored.mClosed.compareAndSet(false, true))
+ if (monitored != null && !monitored.isClosed())
{
Log.w(K9.LOG_TAG, "Forcibly closing remotely exposed cursor");
try
@@ -865,6 +953,9 @@ public class MessageProvider extends ContentProvider
private MessageHelper mMessageHelper;
+ /**
+ * How many simultaneous cursors we can affort to expose at once
+ */
/* package */
Semaphore mSemaphore = new Semaphore(1);