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      1 /*
      2  * Copyright (C) 2007 The Android Open Source Project
      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 import dalvik.system.VMRuntime;
     18 import java.util.concurrent.CountDownLatch;
     19 import static java.util.concurrent.TimeUnit.MINUTES;
     20 
     21 /**
     22  * Test a class with a bad finalizer in an environment with a short finalizer timeout.
     23  *
     24  * This test is inherently flaky. It assumes that the system will schedule the finalizer daemon
     25  * and finalizer watchdog daemon enough to reach the timeout and throwing the fatal exception.
     26  * Largely cloned from 030-bad-finalizer.
     27  */
     28 public class Main {
     29     public static void main(String[] args) throws Exception {
     30         CountDownLatch finalizerWait = new CountDownLatch(1);
     31 
     32         System.out.println("Finalizer timeout = "
     33                 + VMRuntime.getRuntime().getFinalizerTimeoutMs() + " msecs.");
     34         // A separate method to ensure no dex register keeps the object alive.
     35         createBadFinalizer(finalizerWait);
     36 
     37         for (int i = 0; i < 2; i++) {
     38             Runtime.getRuntime().gc();
     39         }
     40 
     41         // Now wait for the finalizer to start running.
     42         if (!finalizerWait.await(1, MINUTES)) {
     43             System.out.println("finalizerWait timed out.");
     44         }
     45 
     46         // Sleep for less time than the default finalizer timeout, but significantly more than
     47         // the new timeout plus the 5 seconds we wait to dump thread stacks before actually
     48         // exiting.
     49         snooze(9800);
     50 
     51         // We should not get here, since it should only take 5.5 seconds for the timed out
     52         // fiinalizer to kill the process.
     53         System.out.println("UNREACHABLE");
     54         System.exit(0);
     55     }
     56 
     57     private static void createBadFinalizer(CountDownLatch finalizerWait) {
     58         BadFinalizer bf = new BadFinalizer(finalizerWait);
     59 
     60         System.out.println("About to null reference.");
     61         bf = null;  // Not that this would make a difference, could be eliminated earlier.
     62     }
     63 
     64     public static void snooze(int ms) {
     65         try {
     66             Thread.sleep(ms);
     67         } catch (InterruptedException ie) {
     68             System.out.println("Snooze(" + ms + ") interrupted");
     69         }
     70     }
     71 
     72     /**
     73      * Class with a bad finalizer.
     74      */
     75     public static class BadFinalizer {
     76         private CountDownLatch finalizerWait;
     77         private volatile int j = 0;  // Volatile in an effort to curb loop optimization.
     78 
     79         public BadFinalizer(CountDownLatch finalizerWait) {
     80             this.finalizerWait = finalizerWait;
     81         }
     82 
     83         protected void finalize() {
     84             System.out.println("Finalizer started and snoozing...");
     85             finalizerWait.countDown();
     86             snooze(200);
     87             System.out.println("Finalizer done snoozing.");
     88 
     89             System.out.println("Finalizer sleeping forever now.");
     90             while (true) {
     91                 snooze(10000);
     92             }
     93         }
     94     }
     95 }
     96