Serialize threading for download manager testing.

The download manager uses threading in a simple way -- it launches two
threads, UpdateThread and DownloadThread, and both are "fire and
forget".  This is fortunate for testing, since it means we can
eliminate multithreading and simply run each thread in order, and
everything still works.

This change does just that, abstracting Thread.start() behind
SystemFacade and making FakeSystemFacade put new threads into a queue
and then run through them serially.  This simplifies much of the test
code and makes it all much more predictable.

I've simplified the test code as much as possible here and moved a few
more tests over to PublicApiFunctionalTest, leaving only a minimum in
DownloadManagerFunctionalTest, which will eventually be deleted
altogether.  I've also improved testing in some areas -- for example,
we can now test that running notifications get cancelled after the
download completes in a robust way.

There is one test case that checks for race conditions and requires
multithreading.  I've moved this into a new ThreadingTest class, which
uses a custom FakeSystemFacade that allows multithreading.  I've
extracted AbstractPublicApiTest for the newly shared code.

Change-Id: Ic1d5c76bfa9913fe053174c3d8b516790ca8b25f

1 files changed, 56 insertions, 0 deletions

diff --git a/tests/src/com/android/providers/downloads/ThreadingTest.java b/tests/src/com/android/providers/downloads/ThreadingTest.java
new file mode 100644
index 00000000..e8d86d66
--- /dev/null
+++ b/tests/src/com/android/providers/downloads/ThreadingTest.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.providers.downloads;
+
+import android.net.DownloadManager;
+import android.test.suitebuilder.annotation.LargeTest;
+
+/**
+ * Download manager tests that require multithreading.
+ */
+@LargeTest
+public class ThreadingTest extends AbstractPublicApiTest {
+    private static class FakeSystemFacadeWithThreading extends FakeSystemFacade {
+        @Override
+        public void startThread(Thread thread) {
+            thread.start();
+        }
+    }
+
+    public ThreadingTest() {
+        super(new FakeSystemFacadeWithThreading());
+    }
+
+    @Override
+    protected void tearDown() throws Exception {
+        Thread.sleep(50); // give threads a chance to finish
+        super.tearDown();
+    }
+
+    /**
+     * Test for race conditions when the service is flooded with startService() calls while running
+     * a download.
+     */
+    public void testFloodServiceWithStarts() throws Exception {
+        enqueueResponse(HTTP_OK, FILE_CONTENT);
+        Download download = enqueueRequest(getRequest());
+        while (download.getStatus() != DownloadManager.STATUS_SUCCESSFUL) {
+            startService(null);
+            Thread.sleep(10);
+        }
+    }
+}