1 /*
2  * Copyright (C) 2019 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 // DeadReferenceSafeTest, but with a reachabilityFence.
18 
19 import dalvik.annotation.optimization.DeadReferenceSafe;
20 import java.lang.ref.Reference;
21 import java.util.concurrent.atomic.AtomicInteger;
22 
23 @DeadReferenceSafe
24 public final class ReachabilityFenceTest {
25   static AtomicInteger nFinalized = new AtomicInteger(0);
26   private static final int INNER_ITERS = 10;
27   static int count;
28   int n = 1;
29 
$noinline$loop()30   private static void $noinline$loop() {
31     ReachabilityFenceTest x;
32     // Each loop allocates INNER_ITERS ReachabilitySenstiveTest objects.
33     for (int i = 0; i < INNER_ITERS; ++i) {
34       // We've allocated i objects so far.
35       x = new ReachabilityFenceTest();
36       count += x.n;
37       // x is dead here.
38       if (i == 5) {
39         // The rechabilityFence should keep the last allocated object reachable.
40         // Thus the last instance should not be finalized.
41         Main.$noinline$gcAndCheck(nFinalized, 5, "ReachabilityFence",
42             "reachabilityFence failed to keep object live.");
43       }
44       Reference.reachabilityFence(x);
45     }
46   }
47 
reset(int expected_count)48   private static void reset(int expected_count) {
49     Runtime.getRuntime().gc();
50     System.runFinalization();
51     if (nFinalized.get() != expected_count) {
52       System.out.println("ReachabilityFenceTest: Wrong number of finalized objects:"
53                          + nFinalized.get());
54     }
55     nFinalized.set(0);
56   }
57 
finalize()58   protected void finalize() {
59     nFinalized.incrementAndGet();
60   }
61 
runTest()62   public static void runTest() {
63     try {
64       Main.ensureCompiled(ReachabilityFenceTest.class, "$noinline$loop");
65     } catch (NoSuchMethodException e) {
66       System.out.println("Unexpectedly threw " + e);
67     }
68 
69     $noinline$loop();
70 
71     if (count != INNER_ITERS) {
72       System.out.println("ReachabilityFenceTest: Final count wrong: " + count);
73     }
74     reset(INNER_ITERS);
75   }
76 }
77