blob: 885b73cd0067b3c20881c4f5cee0ba597cd609c5 [file] [log] [blame]
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.util.concurrent;
import com.google.common.base.Supplier;
import com.google.common.base.Suppliers;
import junit.framework.TestCase;
import java.security.Permission;
import java.util.concurrent.Callable;
/**
* Unit tests for {@link Callables}.
*
* @author Isaac Shum
*/
public class CallablesTest extends TestCase {
public void testReturning() throws Exception {
assertNull(Callables.returning(null).call());
Object value = new Object();
Callable<Object> callable = Callables.returning(value);
assertSame(value, callable.call());
// Expect the same value on subsequent calls
assertSame(value, callable.call());
}
public void testRenaming() throws Exception {
String oldName = Thread.currentThread().getName();
final Supplier<String> newName = Suppliers.ofInstance("MyCrazyThreadName");
Callable<Void> callable = new Callable<Void>() {
@Override public Void call() throws Exception {
assertEquals(Thread.currentThread().getName(), newName.get());
return null;
}
};
Callables.threadRenaming(callable, newName).call();
assertEquals(oldName, Thread.currentThread().getName());
}
public void testRenaming_exceptionalReturn() throws Exception {
String oldName = Thread.currentThread().getName();
final Supplier<String> newName = Suppliers.ofInstance("MyCrazyThreadName");
class MyException extends Exception {}
Callable<Void> callable = new Callable<Void>() {
@Override public Void call() throws Exception {
assertEquals(Thread.currentThread().getName(), newName.get());
throw new MyException();
}
};
try {
Callables.threadRenaming(callable, newName).call();
fail();
} catch (MyException expected) {}
assertEquals(oldName, Thread.currentThread().getName());
}
public void testRenaming_noPermissions() throws Exception {
System.setSecurityManager(new SecurityManager() {
@Override public void checkAccess(Thread t) {
throw new SecurityException();
}
@Override public void checkPermission(Permission perm) {
// Do nothing so we can clear the security manager at the end
}
});
try {
final String oldName = Thread.currentThread().getName();
Supplier<String> newName = Suppliers.ofInstance("MyCrazyThreadName");
Callable<Void> callable = new Callable<Void>() {
@Override public Void call() throws Exception {
assertEquals(Thread.currentThread().getName(), oldName);
return null;
}
};
Callables.threadRenaming(callable, newName).call();
assertEquals(oldName, Thread.currentThread().getName());
} finally {
System.setSecurityManager(null);
}
}
}