1 /*
2 * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 /*
25 * @test
26 * @library /test/lib
27 * @run junit/othervm TrackAllThreads
28 */
29
30 import java.lang.ref.WeakReference;
31 import java.util.concurrent.Executors;
32 import java.util.concurrent.LinkedTransferQueue;
33 import java.util.concurrent.ThreadFactory;
34 import java.util.concurrent.ThreadPoolExecutor;
35 import java.util.concurrent.TimeUnit;
36 import java.util.concurrent.locks.LockSupport;
37
38 import jdk.test.lib.util.ForceGC;
39 import org.junit.jupiter.api.Disabled;
40 import org.junit.jupiter.api.Test;
41 import static org.junit.jupiter.api.Assertions.*;
42
43 class TrackAllThreads {
44
45 /**
46 * Test that a virtual created directly with the Thread API, then parks, is not GC'ed.
47 */
48 @Test
49 void testRootContainer() {
50 Thread thread = Thread.ofVirtual().start(LockSupport::park);
51 var ref = new WeakReference<>(thread);
52 thread = null;
53 ForceGC.waitFor(() -> ref.refersTo(null), 2000);
54 thread = ref.get();
55 if (thread == null) {
56 fail("Thread has been GC'ed");
57 } else {
58 LockSupport.unpark(thread);
59 }
60 }
61
62 /**
63 * Test that a ThreadPoolExecutor using a virtual thread factory can be GC'ed after
64 * the last virtual thread terminates.
65 */
66 @Test
67 void testSharedContainer1() {
68 var queue = new LinkedTransferQueue<Runnable>();
69 ThreadFactory factory = Thread.ofVirtual().factory();
70 var executor = new ThreadPoolExecutor(0, 1, 1, TimeUnit.SECONDS, queue, factory);
71 executor.submit(() -> { });
72 var ref = new WeakReference<>(executor);
73 executor = null;
74 boolean cleared = ForceGC.waitFor(() -> ref.refersTo(null), Long.MAX_VALUE);
75 assertTrue(cleared);
76 }
77
78 /**
79 * Test that a ThreadPoolExecutor using a virtual thread factory is not GC'ed when
80 * a task (running in a virtual thread) has parked.
81 */
82 @Disabled
83 @Test
84 void testSharedContainer2() throws Exception {
85 var queue = new LinkedTransferQueue<Runnable>();
86 ThreadFactory factory = Thread.ofVirtual().factory();
87 var executor = new ThreadPoolExecutor(0, 1, 1, TimeUnit.SECONDS, queue, factory);
88 executor.execute(LockSupport::park);
89 var ref = new WeakReference<>(executor);
90 executor = null;
91 ForceGC.waitFor(() -> ref.refersTo(null), 2000);
92 executor = ref.get();
93 if (executor == null) {
94 fail("Executor has been GC'ed");
95 } else {
96 executor.shutdownNow();
97 executor.close();
98 }
99 }
100
101 /**
102 * Test that a ThreadPerTaskExecutor using a virtual thread factory can be GC'ed after
103 * the last virtual thread terminates.
104 */
105 @Test
106 void testThreadPerTaskExecutor1() {
107 var executor = Executors.newVirtualThreadPerTaskExecutor();
108 executor.submit(() -> { });
109 var ref = new WeakReference<>(executor);
110 executor = null;
111 boolean cleared = ForceGC.waitFor(() -> ref.refersTo(null), Long.MAX_VALUE);
112 assertTrue(cleared);
113 }
114
115 /**
116 * Test that a ThreadPerTaskExecutor using a virtual thread factory is not GC'ed when
117 * a task (running in a virtual thread) has parked.
118 */
119 @Disabled
120 @Test
121 void testThreadPerTaskExecutor2() throws Exception {
122 var executor = Executors.newVirtualThreadPerTaskExecutor();
123 executor.execute(LockSupport::park);
124 var ref = new WeakReference<>(executor);
125 executor = null;
126 ForceGC.waitFor(() -> ref.refersTo(null), 2000);
127 executor = ref.get();
128 if (executor == null) {
129 fail("Executor has been GC'ed");
130 } else {
131 executor.shutdownNow();
132 executor.close();
133 }
134 }
135 }