Break IntraLineDiff threads into their own module

This small refactoring allows me to manually bind the
IntraLineWorkerPool within the gerrit-review server build,
offering better control over how the threads are managed
by this pool.

Change-Id: I26c56ef3c57a86189e1c6a1b668b464e4f079995
This commit is contained in:
Shawn Pearce 2013-02-20 11:20:17 -08:00
parent 7609714b2c
commit 5797d87d6b
4 changed files with 195 additions and 145 deletions

View File

@ -51,13 +51,14 @@ import com.google.gerrit.server.git.ReceiveCommitsExecutorModule;
import com.google.gerrit.server.git.WorkQueue;
import com.google.gerrit.server.mail.SignedTokenEmailTokenVerifier;
import com.google.gerrit.server.mail.SmtpEmailSender;
import com.google.gerrit.server.patch.IntraLineWorkerPool;
import com.google.gerrit.server.plugins.PluginGuiceEnvironment;
import com.google.gerrit.server.plugins.PluginModule;
import com.google.gerrit.server.schema.SchemaUpdater;
import com.google.gerrit.server.schema.SchemaVersionCheck;
import com.google.gerrit.server.schema.UpdateUI;
import com.google.gerrit.server.ssh.NoSshModule;
import com.google.gerrit.server.ssh.NoSshKeyCache;
import com.google.gerrit.server.ssh.NoSshModule;
import com.google.gerrit.sshd.SshKeyCacheImpl;
import com.google.gerrit.sshd.SshModule;
import com.google.gerrit.sshd.commands.MasterCommandModule;
@ -310,6 +311,7 @@ public class Daemon extends SiteProgram {
modules.add(new WorkQueue.Module());
modules.add(new ChangeHookRunner.Module());
modules.add(new ReceiveCommitsExecutorModule());
modules.add(new IntraLineWorkerPool.Module());
modules.add(cfgInjector.getInstance(GerritGlobalModule.class));
modules.add(new DefaultCacheFactory.Module());
modules.add(new SmtpEmailSender.Module());

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@ -29,10 +29,7 @@ import org.slf4j.LoggerFactory;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.regex.Pattern;
class IntraLineLoader extends CacheLoader<IntraLineDiffKey, IntraLineDiff> {
@ -44,16 +41,12 @@ class IntraLineLoader extends CacheLoader<IntraLineDiffKey, IntraLineDiff> {
private static final Pattern CONTROL_BLOCK_START_RE = Pattern
.compile("[{:][ \\t]*$");
private final BlockingQueue<Worker> workerPool;
private final IntraLineWorkerPool workerPool;
private final long timeoutMillis;
@Inject
IntraLineLoader(final @GerritServerConfig Config cfg) {
final int workers =
cfg.getInt("cache", PatchListCacheImpl.INTRA_NAME, "maxIdleWorkers",
Runtime.getRuntime().availableProcessors() * 3 / 2);
workerPool = new ArrayBlockingQueue<Worker>(workers, true /* fair */);
IntraLineLoader(IntraLineWorkerPool pool, @GerritServerConfig Config cfg) {
workerPool = pool;
timeoutMillis =
ConfigUtil.getTimeUnit(cfg, "cache", PatchListCacheImpl.INTRA_NAME,
"timeout", TimeUnit.MILLISECONDS.convert(5, TimeUnit.SECONDS),
@ -62,26 +55,17 @@ class IntraLineLoader extends CacheLoader<IntraLineDiffKey, IntraLineDiff> {
@Override
public IntraLineDiff load(IntraLineDiffKey key) throws Exception {
Worker w = workerPool.poll();
if (w == null) {
w = new Worker();
}
IntraLineWorkerPool.Worker w = workerPool.acquire();
IntraLineWorkerPool.Worker.Result r = w.computeWithTimeout(key, timeoutMillis);
Worker.Result r = w.computeWithTimeout(key, timeoutMillis);
if (r == Worker.Result.TIMEOUT) {
if (r == IntraLineWorkerPool.Worker.Result.TIMEOUT) {
// Don't keep this thread. We have to murder it unsafely, which
// means its unable to be reused in the future. Return back a
// null result, indicating the cache cannot load this key.
//
return new IntraLineDiff(IntraLineDiff.Status.TIMEOUT);
}
if (!workerPool.offer(w)) {
// If the idle worker pool is full, terminate this thread.
//
w.end();
}
workerPool.release(w);
if (r.error != null) {
// If there was an error computing the result, carry it
@ -93,127 +77,7 @@ class IntraLineLoader extends CacheLoader<IntraLineDiffKey, IntraLineDiff> {
return r.diff;
}
private static class Worker {
private static final AtomicInteger count = new AtomicInteger(1);
private final ArrayBlockingQueue<Input> input;
private final ArrayBlockingQueue<Result> result;
private final Thread thread;
Worker() {
input = new ArrayBlockingQueue<Input>(1);
result = new ArrayBlockingQueue<Result>(1);
thread = new Thread(new Runnable() {
public void run() {
workerLoop();
}
});
thread.setName("IntraLineDiff-" + count.getAndIncrement());
thread.setDaemon(true);
thread.start();
}
Result computeWithTimeout(IntraLineDiffKey key, long timeoutMillis)
throws Exception {
if (!input.offer(new Input(key))) {
log.error("Cannot enqueue task to thread " + 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 " + thread.getName());
forcefullyKillThreadInAnUglyWay();
return Result.TIMEOUT;
}
}
@SuppressWarnings("deprecation")
private void forcefullyKillThreadInAnUglyWay() {
try {
thread.stop();
} catch (Throwable error) {
// Ignore any reason the thread won't stop.
log.error("Cannot stop runaway thread " + thread.getName(), error);
}
}
void end() {
if (!input.offer(Input.END_THREAD)) {
log.error("Cannot gracefully stop thread " + thread.getName());
}
}
private void workerLoop() {
try {
for (;;) {
Input in;
try {
in = input.take();
} catch (InterruptedException e) {
log.error("Unexpected interrupt on " + thread.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 " + thread.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;
}
}
}
private static IntraLineDiff compute(IntraLineDiffKey key) throws Exception {
static IntraLineDiff compute(IntraLineDiffKey key) throws Exception {
List<Edit> edits = new ArrayList<Edit>(key.getEdits());
Text aContent = key.getTextA();
Text bContent = key.getTextB();

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@ -0,0 +1,182 @@
// 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;
}
}
}
}

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@ -39,6 +39,7 @@ import com.google.gerrit.server.git.ReceiveCommitsExecutorModule;
import com.google.gerrit.server.git.WorkQueue;
import com.google.gerrit.server.mail.SignedTokenEmailTokenVerifier;
import com.google.gerrit.server.mail.SmtpEmailSender;
import com.google.gerrit.server.patch.IntraLineWorkerPool;
import com.google.gerrit.server.plugins.PluginGuiceEnvironment;
import com.google.gerrit.server.plugins.PluginModule;
import com.google.gerrit.server.schema.DataSourceModule;
@ -229,6 +230,7 @@ public class WebAppInitializer extends GuiceServletContextListener {
modules.add(new WorkQueue.Module());
modules.add(new ChangeHookRunner.Module());
modules.add(new ReceiveCommitsExecutorModule());
modules.add(new IntraLineWorkerPool.Module());
modules.add(cfgInjector.getInstance(GerritGlobalModule.class));
modules.add(new DefaultCacheFactory.Module());
modules.add(new SmtpEmailSender.Module());