1 package org.apache.maven.surefire.junitcore.pc;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 /**
23 * The Balancer controls the maximum of concurrent threads in the current Scheduler(s) and prevents
24 * from own thread resources exhaustion if other group of schedulers share the same pool of threads.
25 * <p>
26 * If a permit is available, {@link #acquirePermit()} simply returns and a new test is scheduled
27 * by {@link Scheduler#schedule(Runnable)} in the current runner. Otherwise waiting for a release.
28 * One permit is released as soon as the child thread has finished.
29 *
30 * @author Tibor Digana (tibor17)
31 * @since 2.16
32 */
33 public interface Balancer {
34
35 /**
36 * Acquires a permit from this balancer, blocking until one is available.
37 *
38 * @return <code>true</code> if current thread is <em>NOT</em> interrupted
39 * while waiting for a permit.
40 */
41 public boolean acquirePermit();
42
43 /**
44 * Releases a permit, returning it to the balancer.
45 */
46 public void releasePermit();
47
48 public void releaseAllPermits();
49 }