1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125
|
/*
* Copyright (c) 2023, 2024, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @test
* @bug 8322818
* @summary Stress test Thread.getStackTrace on a virtual thread that is pinned
* @requires vm.debug != true
* @modules java.base/java.lang:+open
* @library /test/lib
* @run main/othervm GetStackTraceALotWhenPinned 500000
*/
/*
* @test
* @requires vm.debug == true
* @modules java.base/java.lang:+open
* @library /test/lib
* @run main/othervm/timeout=300 GetStackTraceALotWhenPinned 200000
*/
import java.time.Instant;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.locks.LockSupport;
import jdk.test.lib.thread.VThreadRunner;
import jdk.test.lib.thread.VThreadPinner;
public class GetStackTraceALotWhenPinned {
public static void main(String[] args) throws Exception {
// need at least two carrier threads when main thread is a virtual thread
if (Thread.currentThread().isVirtual()) {
VThreadRunner.ensureParallelism(2);
}
int iterations = Integer.parseInt(args[0]);
var barrier = new Barrier(2);
// Start a virtual thread that loops doing Thread.yield and parking while pinned.
// This loop creates the conditions for the main thread to sample the stack trace
// as it transitions from being unmounted to parking while pinned.
var thread = Thread.startVirtualThread(() -> {
boolean timed = false;
for (int i = 0; i < iterations; i++) {
// wait for main thread to arrive
barrier.await();
Thread.yield();
boolean b = timed;
VThreadPinner.runPinned(() -> {
if (b) {
LockSupport.parkNanos(Long.MAX_VALUE);
} else {
LockSupport.park();
}
});
timed = !timed;
}
});
long lastTimestamp = System.currentTimeMillis();
for (int i = 0; i < iterations; i++) {
// wait for virtual thread to arrive
barrier.await();
thread.getStackTrace();
LockSupport.unpark(thread);
long currentTime = System.currentTimeMillis();
if ((currentTime - lastTimestamp) > 500) {
System.out.format("%s %d remaining ...%n", Instant.now(), (iterations - i));
lastTimestamp = currentTime;
}
}
}
/**
* Alow threads wait for each other to reach a common barrier point. This class does
* not park threads that are waiting for the barrier to trip, instead it spins. This
* makes it suitable for tests that use LockSupport.park or Thread.yield.
*/
private static class Barrier {
private final int parties;
private final AtomicInteger count;
private volatile int generation;
Barrier(int parties) {
this.parties = parties;
this.count = new AtomicInteger(parties);
}
void await() {
int g = generation;
if (count.decrementAndGet() == 0) {
count.set(parties);
generation = g + 1;
} else {
while (generation == g) {
Thread.onSpinWait();
}
}
}
}
}
|