Home | History | Annotate | Download | only in ref 
      1 /*
      2  * Copyright (C) 2011 Google Inc.
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  * http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package libcore.java.lang.ref;
     18 
     19 import java.util.concurrent.CountDownLatch;
     20 import java.util.concurrent.atomic.AtomicBoolean;
     21 import java.util.concurrent.atomic.AtomicInteger;
     22 import junit.framework.TestCase;
     23 
     24 public final class FinalizeTest extends TestCase {
     25 
     26     public void testFinalizeIsCalled() throws Exception {
     27         AtomicBoolean finalized = new AtomicBoolean();
     28         createFinalizableObject(finalized);
     29 
     30         FinalizationTester.induceFinalization();
     31         if (!finalized.get()) {
     32             fail("object not yet finalized");
     33         }
     34     }
     35 
     36     /**
     37      * Test verifies that runFinalization() does not mess up objects
     38      * that should be finalized later on. http://b/6907299
     39      */
     40     public void testInducedFinalization() throws Exception {
     41         AtomicBoolean finalized1 = new AtomicBoolean();
     42         AtomicBoolean finalized2 = new AtomicBoolean();
     43         createFinalizableObject(finalized1);
     44         createFinalizableObject(finalized2);
     45         FinalizationTester.induceFinalization();
     46         if (!finalized1.get() || !finalized2.get()) {
     47             fail("not yet finalized: " + finalized1.get() + " " + finalized2.get());
     48         }
     49     }
     50 
     51     /** Do not inline this method; that could break non-precise GCs. See FinalizationTester. */
     52     private X createFinalizableObject(final AtomicBoolean finalized) {
     53         X result = new X() {
     54             @Override protected void finalize() throws Throwable {
     55                 super.finalize();
     56                 finalized.set(true);
     57             }
     58         };
     59         FinalizationTester.induceFinalization();
     60         // Dance around a bit to discourage dx from realizing that 'result' is no longer live.
     61         boolean wasFinalized = finalized.get();
     62         if (wasFinalized) {
     63             fail("finalizer called early"); // ...because 'result' is still live until we return.
     64         }
     65         // But we don't actually want to return 'result' because then we'd have to worry about
     66         // the caller accidentally keeping it live.
     67         return wasFinalized ? result : null;
     68     }
     69 
     70     static class X {}
     71 
     72     // Helper function since we do not want a vreg to keep the allocated object live.
     73     // For b/25851249
     74     private void exceptionInConstructor() {
     75         boolean thrown = false;
     76         try {
     77             new ConstructionFails();
     78             // can't fail() here since AssertionFailedError extends AssertionError, which
     79             // we expect
     80         } catch (AssertionError expected) {
     81             thrown = true;
     82         }
     83         if (!thrown) {
     84             fail();
     85         }
     86     }
     87 
     88     // http://b/issue?id=2136462
     89     public void testBackFromTheDead() throws Exception {
     90         exceptionInConstructor();
     91         FinalizationTester.induceFinalization();
     92         assertTrue("object whose constructor threw was not finalized", ConstructionFails.finalized);
     93     }
     94 
     95     static class ConstructionFails {
     96         private static boolean finalized;
     97 
     98         ConstructionFails() {
     99             throw new AssertionError();
    100         }
    101 
    102         @Override protected void finalize() throws Throwable {
    103             finalized = true;
    104         }
    105     }
    106 
    107     /**
    108      * The finalizer watch dog exits the VM if any object takes more than 10 s
    109      * to finalize. Check that objects near that limit are okay.
    110      */
    111     public void testWatchdogDoesNotFailForObjectsThatAreNearTheDeadline() throws Exception {
    112         CountDownLatch latch = new CountDownLatch(3);
    113         createSlowFinalizer(   1, latch);
    114         createSlowFinalizer(1000, latch);
    115         createSlowFinalizer(8000, latch);
    116         FinalizationTester.induceFinalization();
    117         latch.await();
    118     }
    119 
    120     public void createSlowFinalizer(final long millis, final CountDownLatch latch) {
    121         new Object() {
    122             @Override protected void finalize() throws Throwable {
    123                 System.out.println("finalize sleeping " + millis + " ms");
    124                 Thread.sleep(millis);
    125                 latch.countDown();
    126             }
    127         };
    128     }
    129 
    130     /**
    131      * Make sure that System.runFinalization() returns even if the finalization
    132      * queue is never completely empty. http://b/4193517
    133      */
    134     public void testSystemRunFinalizationReturnsEvenIfQueueIsNonEmpty() throws Exception {
    135         AtomicInteger count = new AtomicInteger();
    136         AtomicBoolean keepGoing = new AtomicBoolean(true);
    137         createChainedFinalizer(count, keepGoing);
    138         FinalizationTester.induceFinalization();
    139         keepGoing.set(false);
    140         assertTrue(count.get() > 0);
    141     }
    142 
    143     public void createChainedFinalizer(final AtomicInteger counter, final AtomicBoolean keepGoing) {
    144         new Object() {
    145             @Override protected void finalize() throws Throwable {
    146                 int count = counter.incrementAndGet();
    147                 System.out.println(count);
    148                 if (keepGoing.get()) {
    149                     createChainedFinalizer(counter, keepGoing); // recursive!
    150                 }
    151                 System.gc();
    152                 FinalizationTester.enqueueReferences();
    153             }
    154         };
    155     }
    156 }
    157