1 /*
2 * Copyright (c) 2022, 2024, 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 * @bug 8284199 8296779 8306647
27 * @summary Basic tests for StructuredTaskScope with scoped values
28 * @enablePreview
29 * @run junit WithScopedValue
30 */
31
32 import java.util.concurrent.StructuredTaskScope;
33 import java.util.concurrent.StructuredTaskScope.Subtask;
34 import java.util.concurrent.StructuredTaskScope.Joiner;
35 import java.util.concurrent.StructureViolationException;
36 import java.util.concurrent.ThreadFactory;
37 import java.util.concurrent.atomic.AtomicBoolean;
38 import java.util.stream.Stream;
39
40 import org.junit.jupiter.api.Test;
41 import org.junit.jupiter.params.ParameterizedTest;
42 import org.junit.jupiter.params.provider.MethodSource;
43 import static org.junit.jupiter.api.Assertions.*;
44
45 class WithScopedValue {
46
47 private static Stream<ThreadFactory> factories() {
48 return Stream.of(Thread.ofPlatform().factory(), Thread.ofVirtual().factory());
49 }
50
51 /**
52 * Test that fork inherits a scoped value into a child thread.
53 */
54 @ParameterizedTest
55 @MethodSource("factories")
56 void testForkInheritsScopedValue1(ThreadFactory factory) throws Exception {
57 ScopedValue<String> name = ScopedValue.newInstance();
58 String value = ScopedValue.where(name, "x").call(() -> {
59 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
60 cf -> cf.withThreadFactory(factory))) {
61 Subtask<String> subtask = scope.fork(() -> {
62 return name.get(); // child should read "x"
63 });
64 scope.join();
65 return subtask.get();
66 }
67 });
68 assertEquals(value, "x");
69 }
70
71 /**
72 * Test that fork inherits a scoped value into a grandchild thread.
73 */
74 @ParameterizedTest
75 @MethodSource("factories")
76 void testForkInheritsScopedValue2(ThreadFactory factory) throws Exception {
77 ScopedValue<String> name = ScopedValue.newInstance();
78 String value = ScopedValue.where(name, "x").call(() -> {
79 try (var scope1 = StructuredTaskScope.open(Joiner.awaitAll(),
80 cf -> cf.withThreadFactory(factory))) {
81 Subtask<String> subtask1 = scope1.fork(() -> {
82 try (var scope2 = StructuredTaskScope.open(Joiner.awaitAll(),
83 cf -> cf.withThreadFactory(factory))) {
84 Subtask<String> subtask2 = scope2.fork(() -> {
85 return name.get(); // grandchild should read "x"
86 });
87 scope2.join();
88 return subtask2.get();
89 }
90 });
91 scope1.join();
92 return subtask1.get();
93 }
94 });
95 assertEquals(value, "x");
96 }
97
98 /**
99 * Test that fork inherits a rebound scoped value into a grandchild thread.
100 */
101 @ParameterizedTest
102 @MethodSource("factories")
103 void testForkInheritsScopedValue3(ThreadFactory factory) throws Exception {
104 ScopedValue<String> name = ScopedValue.newInstance();
105 String value = ScopedValue.where(name, "x").call(() -> {
106 try (var scope1 = StructuredTaskScope.open(Joiner.awaitAll(),
107 cf -> cf.withThreadFactory(factory))) {
108 Subtask<String> subtask1 = scope1.fork(() -> {
109 assertEquals(name.get(), "x"); // child should read "x"
110
111 // rebind name to "y"
112 String grandchildValue = ScopedValue.where(name, "y").call(() -> {
113 try (var scope2 = StructuredTaskScope.open(Joiner.awaitAll(),
114 cf -> cf.withThreadFactory(factory))) {
115 Subtask<String> subtask2 = scope2.fork(() -> {
116 return name.get(); // grandchild should read "y"
117 });
118 scope2.join();
119 return subtask2.get();
120 }
121 });
122
123 assertEquals(name.get(), "x"); // child should read "x"
124 return grandchildValue;
125 });
126 scope1.join();
127 return subtask1.get();
128 }
129 });
130 assertEquals(value, "y");
131 }
132
133 /**
134 * Test exiting a dynamic scope with an open task scope.
135 */
136 @Test
137 void testStructureViolation1() throws Exception {
138 ScopedValue<String> name = ScopedValue.newInstance();
139 class Box {
140 StructuredTaskScope<Object, Void> scope;
141 }
142 var box = new Box();
143 try {
144 try {
145 ScopedValue.where(name, "x").run(() -> {
146 box.scope = StructuredTaskScope.open(Joiner.awaitAll());
147 });
148 fail();
149 } catch (StructureViolationException expected) { }
150
151 // underlying flock should be closed and fork should fail to start a thread
152 StructuredTaskScope<Object, Void> scope = box.scope;
153 AtomicBoolean ran = new AtomicBoolean();
154 Subtask<Object> subtask = scope.fork(() -> {
155 ran.set(true);
156 return null;
157 });
158 scope.join();
159 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
160 assertFalse(ran.get());
161 } finally {
162 StructuredTaskScope<Object, Void> scope = box.scope;
163 if (scope != null) {
164 scope.close();
165 }
166 }
167 }
168
169 /**
170 * Test closing a StructuredTaskScope while executing in a dynamic scope.
171 */
172 @Test
173 void testStructureViolation2() throws Exception {
174 ScopedValue<String> name = ScopedValue.newInstance();
175 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
176 ScopedValue.where(name, "x").run(() -> {
177 assertThrows(StructureViolationException.class, scope::close);
178 });
179 }
180 }
181
182 /**
183 * Test fork when a scoped value is bound after a StructuredTaskScope is created.
184 */
185 @Test
186 void testStructureViolation3() throws Exception {
187 ScopedValue<String> name = ScopedValue.newInstance();
188 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
189 ScopedValue.where(name, "x").run(() -> {
190 assertThrows(StructureViolationException.class,
191 () -> scope.fork(() -> "foo"));
192 });
193 }
194 }
195
196 /**
197 * Test fork when a scoped value is re-bound after a StructuredTaskScope is created.
198 */
199 @Test
200 void testStructureViolation4() throws Exception {
201 ScopedValue<String> name1 = ScopedValue.newInstance();
202 ScopedValue<String> name2 = ScopedValue.newInstance();
203
204 // rebind
205 ScopedValue.where(name1, "x").run(() -> {
206 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
207 ScopedValue.where(name1, "y").run(() -> {
208 assertThrows(StructureViolationException.class,
209 () -> scope.fork(() -> "foo"));
210 });
211 }
212 });
213
214 // new binding
215 ScopedValue.where(name1, "x").run(() -> {
216 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
217 ScopedValue.where(name2, "y").run(() -> {
218 assertThrows(StructureViolationException.class,
219 () -> scope.fork(() -> "foo"));
220 });
221 }
222 });
223 }
224 }