1 /*
 2  * Copyright (c) 2025, 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
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22  */
23 
24 /*
25  * @test
26  * @modules java.base/jdk.internal.foreign
27  * @build NativeTestHelper TestBufferStackStress
28  * @run junit/timeout=480 TestBufferStackStress
29  */
30 
31 import jdk.internal.foreign.BufferStack;
32 import org.junit.jupiter.api.Test;
33 
34 import java.lang.foreign.Arena;
35 import java.lang.foreign.MemorySegment;
36 import java.time.Duration;
37 import java.util.Arrays;
38 import java.util.stream.IntStream;
39 
40 import static java.lang.foreign.ValueLayout.*;
41 import static java.time.temporal.ChronoUnit.SECONDS;
42 import static org.junit.jupiter.api.Assertions.*;
43 
44 public class TestBufferStackStress {
45 
46     @Test
47     public void stress() throws InterruptedException {
48         BufferStack stack = BufferStack.of(256, 1);
49         Thread[] vThreads = IntStream.range(0, 1024).mapToObj(_ ->
50                 Thread.ofVirtual().start(() -> {
51                     long threadId = Thread.currentThread().threadId();
52                     while (!Thread.interrupted()) {
53                         for (int i = 0; i < 1_000_000; i++) {
54                             try (Arena arena = stack.pushFrame(JAVA_LONG.byteSize(), JAVA_LONG.byteAlignment())) {
55                                 // Try to assert no two vThreads get allocated the same stack space.
56                                 MemorySegment segment = arena.allocate(JAVA_LONG);
57                                 JAVA_LONG.varHandle().setVolatile(segment, 0L, threadId);
58                                 assertEquals(threadId, (long) JAVA_LONG.varHandle().getVolatile(segment, 0L));
59                             }
60                         }
61                         Thread.yield(); // make sure the driver thread gets a chance.
62                     }
63                 })).toArray(Thread[]::new);
64         Thread.sleep(Duration.of(10, SECONDS));
65         Arrays.stream(vThreads).forEach(
66                 thread -> {
67                     assertTrue(thread.isAlive());
68                     thread.interrupt();
69                 });
70     }
71 
72 }