/hudson-core/src/main/java/hudson/model/queue/Latch.java
http://github.com/hudson/hudson · Java · 95 lines · 48 code · 11 blank · 36 comment · 6 complexity · 89b2244a1e5265bfdff233acd046fddd MD5 · raw file
- /*
- * The MIT License
- *
- * Copyright (c) 2010, InfraDNA, Inc.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
- package hudson.model.queue;
- import hudson.AbortException;
- /**
- * A concurrency primitive that waits for N number of threads to synchronize.
- * If any of the threads are interrupted while waiting for the completion of the condition,
- * then all the involved threads get interrupted.
- *
- * @author Kohsuke Kawaguchi
- */
- class Latch {
- private final int n;
- private int i=0;
- /**
- * If the synchronization on the latch is aborted/interrupted,
- * point to the stack trace where that happened. If null,
- * no interruption happened.
- */
- private Exception interrupted;
- public Latch(int n) {
- this.n = n;
- }
- public synchronized void abort(Throwable cause) {
- interrupted = new AbortException();
- if (cause!=null)
- interrupted.initCause(cause);
- notifyAll();
- }
- public synchronized void synchronize() throws InterruptedException {
- check(n);
- try {
- onCriteriaMet();
- } catch (Error e) {
- abort(e);
- throw e;
- } catch (RuntimeException e) {
- abort(e);
- throw e;
- }
- check(n*2);
- }
- private void check(int threshold) throws InterruptedException {
- i++;
- if (i==threshold) {
- notifyAll();
- } else {
- while (i<threshold && interrupted==null) {
- try {
- wait();
- } catch (InterruptedException e) {
- interrupted = e;
- notifyAll();
- throw e;
- }
- }
- }
- // all of us either leave normally or get interrupted
- if (interrupted!=null)
- throw (InterruptedException)new InterruptedException().initCause(interrupted);
- }
- protected void onCriteriaMet() throws InterruptedException {}
- }