michael-o commented on a change in pull request #77: URL: https://github.com/apache/maven-resolver/pull/77#discussion_r611854531
########## File path: maven-resolver-named-locks/src/main/java/org/eclipse/aether/named/NamedLock.java ########## @@ -0,0 +1,71 @@ +package org.eclipse.aether.named; + +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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. + */ + +import java.util.concurrent.TimeUnit; + +/** + * A named lock, functionally similar to existing JVM and other implementations. Must support boxing (reentrancy), but + * no lock upgrade is supported. Usual pattern to use this lock: + * <pre> + * try (NamedLock lock = factory.getLock("resourceName")) { + * if (lock.lockExclusively(10L, Timeunit.SECONDS)) { + * try { + * ... exclusive access to "resourceName" resource gained here + * } + * finally { + * lock.unlock(); + * } + * } + * else { + * ... failed to gain access within specified time, handle it + * } + * } + * </pre> + */ +public interface NamedLock + extends AutoCloseable +{ + /** + * Returns this instance name, never null. + */ + String name(); + + /** + * Tries to lock shared, may block for given time. If successful, returns {@code true}. + */ + boolean lockShared( long time, TimeUnit unit ) throws InterruptedException; + + /** + * Tries to lock exclusively, may block for given time. If successful, returns {@code true}. + */ + boolean lockExclusively( long time, TimeUnit unit ) throws InterruptedException; + + /** + * Unlocks the lock. + */ + void unlock(); + + /** + * Closes the lock. + */ + @Override + void close(); Review comment: This is better. Though the wording could be better: * When should be `close()` be performed before or after `unlock()`? * What happens when `close()` is called before `lock()`? Undefined behavior? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
