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