1 /*
2  * Copyright (C) 2017 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 package art;
18 
19 public class Test1942 {
run()20   public static void run() throws Exception {
21     final Thread target_thread = new Thread(() -> {
22       nativeRun();
23     }, "target_thread");
24 
25     target_thread.start();
26 
27     // wait for the other thread to spin holding lock.
28     waitForPause();
29 
30     System.out.println("Initial state.");
31     System.out.println("isLocked() = " + isLocked());
32     System.out.println("isSuspended(target_thread) = " + Suspension.isSuspended(target_thread));
33 
34     // Suspend it from java.
35     System.out.println("Suspend and sleep.");
36     Suspension.suspend(target_thread);
37     // Wait for the other thread to do something.
38     try { Thread.sleep(1000); } catch (Exception e) {}
39 
40     System.out.println("isLocked() = " + isLocked());
41     System.out.println("isSuspended(target_thread) = " + Suspension.isSuspended(target_thread));
42 
43     // Let it try to unlock the monitor.
44     System.out.println("Let other thread release the raw monitor.");
45     // Let the thread try to lock the monitor.
46     resume();
47 
48     // Wait for the other thread to do something. It should exit by the time this is done if it
49     // has not hit a suspend point.
50     while (isLocked()) {
51       try { Thread.sleep(1000); } catch (Exception e) {}
52     }
53 
54     System.out.println("isLocked() = " + isLocked());
55     System.out.println("isSuspended(target_thread) = " + Suspension.isSuspended(target_thread));
56 
57     // Make sure the monitor is gone.
58     grabRawMonitor();
59     System.out.println("other thread doesn't hold lock!");
60 
61     // Resume it from java
62     System.out.println("resumed test thread");
63     Suspension.resume(target_thread);
64     target_thread.join();
65   }
66 
nativeRun()67   public static native void nativeRun();
waitForPause()68   public static native void waitForPause();
resume()69   public static native void resume();
isLocked()70   public static native boolean isLocked();
71   // Gets then releases raw monitor.
grabRawMonitor()72   public static native void grabRawMonitor();
73 }
74