add shutdown() to ContentProvider & call in ProviderTestCase*.tearDown
Change-Id: I3dd69b6907d68b7c1184139f22297ab92337f043
diff --git a/core/java/android/content/ContentProvider.java b/core/java/android/content/ContentProvider.java
index 9b9f796..a3252ed 100644
--- a/core/java/android/content/ContentProvider.java
+++ b/core/java/android/content/ContentProvider.java
@@ -32,6 +32,7 @@
import android.os.Bundle;
import android.os.ParcelFileDescriptor;
import android.os.Process;
+import android.util.Log;
import java.io.File;
import java.io.FileNotFoundException;
@@ -76,6 +77,8 @@
* cross-process calls.</p>
*/
public abstract class ContentProvider implements ComponentCallbacks {
+ private static final String TAG = "ContentProvider";
+
/*
* Note: if you add methods to ContentProvider, you must add similar methods to
* MockContentProvider.
@@ -831,4 +834,34 @@
public Bundle call(String method, String request, Bundle args) {
return null;
}
+
+ /**
+ * Shuts down this instance of the ContentProvider. It is useful when writing tests that use
+ * the ContentProvider.
+ * <p>
+ * If a unittest starts the ContentProvider in its test(..() methods, it could run into sqlite
+ * errors "disk I/O error" or "corruption" in the following scenario:
+ * <ul>
+ * <li>Say, there are 2 test methods in the unittest</li>
+ * <li>test1() (or setUp()) causes ContentProvider object to be initialized and
+ * assume it opens a database connection to "foo.db"</li>
+ * <li>est1() completes and test2() starts</li>
+ * <li>During the execution of test2() there will be 2 connections to "foo.db"</li>
+ * <li>Different threads in the ContentProvider may have one of these two connection
+ * handles. This is not a problem per se</li>
+ * <li>But if the two threads with 2 database connections don't interact correctly,
+ * there could be unexpected errors from sqlite</li>
+ * <li>Some of those unexpected errros are "disk I/O error" or "corruption" error</li>
+ * <li>Common practice in tearDown() is to delete test directory (and the database files)</li>
+ * <li>If this is done while some threads are still holding unclosed database connections,
+ * sqlite quite easily gets into corruption and disk I/O errors</li>
+ * </ul>
+ * <p>
+ * tearDown() in the unittests should call this method to have ContentProvider gracefully
+ * shutdown all database connections.
+ */
+ public void shutdown() {
+ Log.w(TAG, "implement ContentProvider shutdown() to make sure all database " +
+ "connections are gracefully shutdown");
+ }
}