1 /*
2 * Copyright (c) 2022, 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 * @summary Stress test ScopedValue with many bindings and rebinings
27 * @modules jdk.incubator.concurrent
28 * @library /test/lib
29 * @key randomness
30 * @run junit ManyBindings
31 */
32
33 import jdk.incubator.concurrent.ScopedValue;
34 import jdk.incubator.concurrent.ScopedValue.Carrier;
35 import java.util.Arrays;
36 import java.util.Objects;
37 import java.util.Random;
38
39 import jdk.test.lib.RandomFactory;
40 import jdk.test.lib.thread.VThreadRunner;
41
42 import org.junit.jupiter.api.Test;
43 import static org.junit.jupiter.api.Assertions.*;
44
45 class ManyBindings {
46 private static final Random RND = RandomFactory.getRandom();
47
48 // number of scoped values to create
49 private static final int SCOPED_VALUE_COUNT = 16;
50
51 // recursive depth to test
52 private static final int MAX_DEPTH = 24;
53
54 /**
55 * Stress test bindings on platform thread.
56 */
57 @Test
58 void testPlatformThread() {
59 test();
60 }
61
62 /**
63 * Stress test bindings on virtual thread.
64 */
65 @Test
66 void testVirtualThread() throws Exception {
67 VThreadRunner.run(() -> test());
68 }
69
70 /**
71 * Scoped value and its expected value (or null if not bound).
72 */
73 record KeyAndValue<T>(ScopedValue<T> key, T value) {
74 KeyAndValue() {
75 this(ScopedValue.newInstance(), null);
76 }
77 }
78
79 /**
80 * Stress test bindings on current thread.
81 */
82 private void test() {
83 KeyAndValue<Integer>[] array = new KeyAndValue[SCOPED_VALUE_COUNT];
84 for (int i = 0; i < array.length; i++) {
85 array[i] = new KeyAndValue<>();
86 }
87 test(array, 1);
88 }
89
90 /**
91 * Test that the scoped values in the array have the expected value, then
92 * recursively call this method with some of the scoped values bound to a
93 * new value.
94 *
95 * @param array the scoped values and their expected value
96 * @param depth current recurive depth
97 */
98 private void test(KeyAndValue<Integer>[] array, int depth) {
99 if (depth > MAX_DEPTH)
100 return;
101
102 // check that the scoped values have the expected values
103 check(array);
104
105 // try to pollute the cache
106 lotsOfReads(array);
107
108 // create a Carrier to bind/rebind some of the scoped values
109 int len = array.length;
110 Carrier carrier = null;
111
112 KeyAndValue<Integer>[] newArray = Arrays.copyOf(array, len);
113 int n = Math.max(1, RND.nextInt(len / 2));
114 while (n > 0) {
115 int index = RND.nextInt(len);
116 ScopedValue<Integer> key = array[index].key;
117 int newValue = RND.nextInt();
118 if (carrier == null) {
119 carrier = ScopedValue.where(key, newValue);
120 } else {
121 carrier = carrier.where(key, newValue);
122 }
123 newArray[index] = new KeyAndValue<>(key, newValue);
124 n--;
125 }
126
127 // invoke recursively
128 carrier.run(() -> {
129 test(newArray, depth+1);
130 });
131
132 // check that the scoped values have the origina values
133 check(array);
134 }
135
136 /**
137 * Check that the given scoped values have the expected value.
138 */
139 private void check(KeyAndValue<Integer>[] array) {
140 for (int i = 0; i < array.length; i++) {
141 ScopedValue<Integer> key = array[i].key;
142 Integer value = array[i].value;
143 if (value == null) {
144 assertFalse(key.isBound());
145 } else {
146 assertEquals(value, key.get());
147 }
148 }
149 }
150
151 /**
152 * Do lots of reads of the scoped values, to pollute the SV cache.
153 */
154 private void lotsOfReads(KeyAndValue<Integer>[] array) {
155 for (int k = 0; k < 1000; k++) {
156 int index = RND.nextInt(array.length);
157 Integer value = array[index].value;
158 if (value != null) {
159 ScopedValue<Integer> key = array[index].key;
160 assertEquals(value, key.get());
161 }
162 }
163 }
164 }