| // Copyright (C) 2009 The Android Open Source Project |
| // |
| // 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.gerrit.server.patch; |
| |
| import static com.google.gerrit.server.patch.IntraLineLoader.log; |
| |
| import com.google.gerrit.server.config.GerritServerConfig; |
| import com.google.inject.AbstractModule; |
| import com.google.inject.Inject; |
| import com.google.inject.Singleton; |
| |
| import org.eclipse.jgit.lib.Config; |
| |
| import java.util.concurrent.ArrayBlockingQueue; |
| import java.util.concurrent.BlockingQueue; |
| import java.util.concurrent.TimeUnit; |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| @Singleton |
| public class IntraLineWorkerPool { |
| public static class Module extends AbstractModule { |
| @Override |
| protected void configure() { |
| bind(IntraLineWorkerPool.class); |
| } |
| } |
| |
| private final BlockingQueue<Worker> workerPool; |
| |
| @Inject |
| public IntraLineWorkerPool(@GerritServerConfig Config cfg) { |
| int workers = cfg.getInt( |
| "cache", PatchListCacheImpl.INTRA_NAME, "maxIdleWorkers", |
| Runtime.getRuntime().availableProcessors() * 3 / 2); |
| workerPool = new ArrayBlockingQueue<Worker>(workers, true /* fair */); |
| } |
| |
| Worker acquire() { |
| Worker w = workerPool.poll(); |
| if (w == null) { |
| // If no worker is immediately available, start a new one. |
| // Maximum parallelism is controlled by the web server. |
| w = new Worker(); |
| w.start(); |
| } |
| return w; |
| } |
| |
| void release(Worker w) { |
| if (!workerPool.offer(w)) { |
| // If the idle worker pool is full, terminate the worker. |
| w.shutdownGracefully(); |
| } |
| } |
| |
| static class Worker extends Thread { |
| private static final AtomicInteger count = new AtomicInteger(1); |
| |
| private final ArrayBlockingQueue<Input> input; |
| private final ArrayBlockingQueue<Result> result; |
| |
| Worker() { |
| input = new ArrayBlockingQueue<Input>(1); |
| result = new ArrayBlockingQueue<Result>(1); |
| |
| setName("IntraLineDiff-" + count.getAndIncrement()); |
| setDaemon(true); |
| } |
| |
| Result computeWithTimeout(IntraLineDiffKey key, long timeoutMillis) |
| throws Exception { |
| if (!input.offer(new Input(key))) { |
| log.error("Cannot enqueue task to thread " + getName()); |
| return Result.TIMEOUT; |
| } |
| |
| Result r = result.poll(timeoutMillis, TimeUnit.MILLISECONDS); |
| if (r != null) { |
| return r; |
| } else { |
| log.warn(timeoutMillis + " ms timeout reached for IntraLineDiff" |
| + " in project " + key.getProject().get() |
| + " on commit " + key.getCommit().name() |
| + " for path " + key.getPath() |
| + " comparing " + key.getBlobA().name() |
| + ".." + key.getBlobB().name() |
| + ". Killing " + getName()); |
| forcefullyKillThreadInAnUglyWay(); |
| return Result.TIMEOUT; |
| } |
| } |
| |
| @SuppressWarnings("deprecation") |
| private void forcefullyKillThreadInAnUglyWay() { |
| try { |
| stop(); |
| } catch (Throwable error) { |
| // Ignore any reason the thread won't stop. |
| log.error("Cannot stop runaway thread " + getName(), error); |
| } |
| } |
| |
| private void shutdownGracefully() { |
| if (!input.offer(Input.END_THREAD)) { |
| log.error("Cannot gracefully stop thread " + getName()); |
| } |
| } |
| |
| @Override |
| public void run() { |
| try { |
| for (;;) { |
| Input in; |
| try { |
| in = input.take(); |
| } catch (InterruptedException e) { |
| log.error("Unexpected interrupt on " + getName()); |
| continue; |
| } |
| |
| if (in == Input.END_THREAD) { |
| return; |
| } |
| |
| Result r; |
| try { |
| r = new Result(IntraLineLoader.compute(in.key)); |
| } catch (Exception error) { |
| r = new Result(error); |
| } |
| |
| if (!result.offer(r)) { |
| log.error("Cannot return result from " + getName()); |
| } |
| } |
| } catch (ThreadDeath iHaveBeenShot) { |
| // Handle thread death by gracefully returning to the caller, |
| // allowing the thread to be destroyed. |
| } |
| } |
| |
| private static class Input { |
| static final Input END_THREAD = new Input(null); |
| |
| final IntraLineDiffKey key; |
| |
| Input(IntraLineDiffKey key) { |
| this.key = key; |
| } |
| } |
| |
| static class Result { |
| static final Result TIMEOUT = new Result((IntraLineDiff) null); |
| |
| final IntraLineDiff diff; |
| final Exception error; |
| |
| Result(IntraLineDiff diff) { |
| this.diff = diff; |
| this.error = null; |
| } |
| |
| Result(Exception error) { |
| this.diff = null; |
| this.error = error; |
| } |
| } |
| } |
| } |