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