commit 1b92f6d964fe86ed56334dfdef7aa30f862bfeab
author vadimt <vadimt@google.com> Fri Oct 04 11:00:01 2019 -0700
committer Vadim Tryshev <vadimt@google.com> Tue Oct 08 01:05:41 2019 +0000
tree 7fd34fa61255249f7ed52c5c0309e3567186ef44
parent 1ab5de3fc8729be8e2e41bd96070e50474434173

Reduce risk of flakes in memory leak detection tests.

Now performing jreck@-style garbage collection prior to getting Launcher
PSS. The reduces PSS noise from ~700KB to ~250KB (std dev).

The tests (MemoryTests) run outside of Launcher process and
communicate with Launcher via RPC.

The change is in the RPC handler that lives in Launcher and returns
Launcher PSS to the test.

Bug: 139137636
Change-Id: I457e590b005dac53345f4223d972c7961754938c

src/com/android/launcher3/testing/TestInformationHandler.java

diff --git a/src/com/android/launcher3/testing/TestInformationHandler.java b/src/com/android/launcher3/testing/TestInformationHandler.java
index 619293b..7931c96 100644
--- a/src/com/android/launcher3/testing/TestInformationHandler.java
+++ b/src/com/android/launcher3/testing/TestInformationHandler.java
@@ -36,7 +36,9 @@
 import com.android.launcher3.util.ResourceBasedOverride;
 
 import java.util.LinkedList;
+import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
 
 public class TestInformationHandler implements ResourceBasedOverride {
 
@@ -137,6 +139,7 @@
             }
 
             case TestProtocol.REQUEST_TOTAL_PSS_KB: {
+                runGcAndFinalizersSync();
                 Debug.MemoryInfo mem = new Debug.MemoryInfo();
                 Debug.getMemoryInfo(mem);
                 response.putInt(TestProtocol.TEST_INFO_RESPONSE_FIELD, mem.getTotalPss());
@@ -173,4 +176,29 @@
         final LauncherModel model = LauncherAppState.getInstance(mContext).getModel();
         return model.getCallback() == null || model.isModelLoaded();
     }
+
+    private static void runGcAndFinalizersSync() {
+        Runtime.getRuntime().gc();
+        Runtime.getRuntime().runFinalization();
+
+        final CountDownLatch fence = new CountDownLatch(1);
+        new Object() {
+            @Override
+            protected void finalize() throws Throwable {
+                try {
+                    fence.countDown();
+                } finally {
+                    super.finalize();
+                }
+            }
+        };
+        try {
+            do {
+                Runtime.getRuntime().gc();
+                Runtime.getRuntime().runFinalization();
+            } while (!fence.await(100, TimeUnit.MILLISECONDS));
+        } catch (InterruptedException ex) {
+            throw new RuntimeException(ex);
+        }
+    }
 }