com.google.gerrit.server.git.WorkQueue Maven / Gradle / Ivy
// 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.git;
import static java.util.stream.Collectors.toList;
import com.google.common.base.CaseFormat;
import com.google.common.flogger.FluentLogger;
import com.google.gerrit.common.Nullable;
import com.google.gerrit.entities.Project;
import com.google.gerrit.extensions.events.LifecycleListener;
import com.google.gerrit.extensions.registration.DynamicMap;
import com.google.gerrit.lifecycle.LifecycleModule;
import com.google.gerrit.metrics.Description;
import com.google.gerrit.metrics.MetricMaker;
import com.google.gerrit.server.config.GerritServerConfig;
import com.google.gerrit.server.config.ScheduleConfig.Schedule;
import com.google.gerrit.server.logging.LoggingContext;
import com.google.gerrit.server.logging.LoggingContextAwareRunnable;
import com.google.gerrit.server.plugincontext.PluginMapContext;
import com.google.gerrit.server.util.IdGenerator;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import java.lang.reflect.Field;
import java.time.Instant;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.Delayed;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.RunnableScheduledFuture;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;
import org.eclipse.jgit.lib.Config;
/** Delayed execution of tasks using a background thread pool. */
@Singleton
public class WorkQueue {
private static final FluentLogger logger = FluentLogger.forEnclosingClass();
/**
* To register a TaskListener, which will be called directly before Tasks run, and directly after
* they complete, bind the TaskListener like this:
*
*
* bind(TaskListener.class)
* .annotatedWith(Exports.named("MyListener"))
* .to(MyListener.class);
*
*/
public interface TaskListener {
public static class NoOp implements TaskListener {
@Override
public void onStart(Task task) {}
@Override
public void onStop(Task task) {}
}
void onStart(Task task);
void onStop(Task task);
}
public static class Lifecycle implements LifecycleListener {
private final WorkQueue workQueue;
@Inject
Lifecycle(WorkQueue workQeueue) {
this.workQueue = workQeueue;
}
@Override
public void start() {}
@Override
public void stop() {
workQueue.stop();
}
}
public static class WorkQueueModule extends LifecycleModule {
@Override
protected void configure() {
DynamicMap.mapOf(binder(), WorkQueue.TaskListener.class);
bind(WorkQueue.class);
listener().to(Lifecycle.class);
}
}
private final ScheduledExecutorService defaultQueue;
private final IdGenerator idGenerator;
private final MetricMaker metrics;
private final CopyOnWriteArrayList queues;
private final PluginMapContext listeners;
@Inject
WorkQueue(
IdGenerator idGenerator,
@GerritServerConfig Config cfg,
MetricMaker metrics,
PluginMapContext listeners) {
this(
idGenerator,
Math.max(cfg.getInt("execution", "defaultThreadPoolSize", 2), 2),
metrics,
listeners);
}
/** Constructor to allow binding the WorkQueue more explicitly in a vhost setup. */
public WorkQueue(
IdGenerator idGenerator,
int defaultThreadPoolSize,
MetricMaker metrics,
PluginMapContext listeners) {
this.idGenerator = idGenerator;
this.metrics = metrics;
this.queues = new CopyOnWriteArrayList<>();
this.defaultQueue = createQueue(defaultThreadPoolSize, "WorkQueue", true);
this.listeners = listeners;
}
/** Get the default work queue, for miscellaneous tasks. */
public ScheduledExecutorService getDefaultQueue() {
return defaultQueue;
}
/**
* Create a new executor queue.
*
* Creates a new executor queue without associated metrics. This method is suitable for use by
* plugins.
*
*
If metrics are needed, use {@link #createQueue(int, String, int, boolean)} instead.
*
* @param poolsize the size of the pool.
* @param queueName the name of the queue.
*/
public ScheduledExecutorService createQueue(int poolsize, String queueName) {
return createQueue(poolsize, queueName, Thread.NORM_PRIORITY, false);
}
/**
* Create a new executor queue, with default priority, optionally with metrics.
*
*
Creates a new executor queue, optionally with associated metrics. Metrics should not be
* requested for queues created by plugins.
*
* @param poolsize the size of the pool.
* @param queueName the name of the queue.
* @param withMetrics whether to create metrics.
*/
public ScheduledThreadPoolExecutor createQueue(
int poolsize, String queueName, boolean withMetrics) {
return createQueue(poolsize, queueName, Thread.NORM_PRIORITY, withMetrics);
}
/**
* Create a new executor queue, optionally with metrics.
*
*
Creates a new executor queue, optionally with associated metrics. Metrics should not be
* requested for queues created by plugins.
*
* @param poolsize the size of the pool.
* @param queueName the name of the queue.
* @param threadPriority thread priority.
* @param withMetrics whether to create metrics.
*/
@SuppressWarnings("ThreadPriorityCheck")
public ScheduledThreadPoolExecutor createQueue(
int poolsize, String queueName, int threadPriority, boolean withMetrics) {
Executor executor = new Executor(poolsize, queueName);
if (withMetrics) {
logger.atInfo().log("Adding metrics for '%s' queue", queueName);
executor.buildMetrics(queueName);
}
executor.setContinueExistingPeriodicTasksAfterShutdownPolicy(false);
executor.setExecuteExistingDelayedTasksAfterShutdownPolicy(true);
queues.add(executor);
if (threadPriority != Thread.NORM_PRIORITY) {
ThreadFactory parent = executor.getThreadFactory();
executor.setThreadFactory(
task -> {
Thread t = parent.newThread(task);
t.setPriority(threadPriority);
return t;
});
}
return executor;
}
/** Executes a periodic command at a fixed schedule on the default queue. */
public void scheduleAtFixedRate(Runnable command, Schedule schedule) {
@SuppressWarnings("unused")
Future possiblyIgnoredError =
getDefaultQueue()
.scheduleAtFixedRate(
command, schedule.initialDelay(), schedule.interval(), TimeUnit.MILLISECONDS);
}
/** Get all of the tasks currently scheduled in any work queue. */
public List> getTasks() {
final List> r = new ArrayList<>();
for (Executor e : queues) {
e.addAllTo(r);
}
return r;
}
public List getTaskInfos(TaskInfoFactory factory) {
List taskInfos = new ArrayList<>();
for (Executor exe : queues) {
for (Task task : exe.getTasks()) {
taskInfos.add(factory.getTaskInfo(task));
}
}
return taskInfos;
}
/** Locate a task by its unique id, null if no task matches. */
@Nullable
public Task getTask(int id) {
Task result = null;
for (Executor e : queues) {
final Task t = e.getTask(id);
if (t != null) {
if (result != null) {
// Don't return the task if we have a duplicate. Lie instead.
return null;
}
result = t;
}
}
return result;
}
@Nullable
public ScheduledThreadPoolExecutor getExecutor(String queueName) {
for (Executor e : queues) {
if (e.queueName.equals(queueName)) {
return e;
}
}
return null;
}
private void stop() {
for (Executor p : queues) {
p.shutdown();
boolean isTerminated;
do {
try {
isTerminated = p.awaitTermination(10, TimeUnit.SECONDS);
} catch (InterruptedException ie) {
isTerminated = false;
}
} while (!isTerminated);
}
queues.clear();
}
/** An isolated queue. */
private class Executor extends ScheduledThreadPoolExecutor {
private final ConcurrentHashMap> all;
private final String queueName;
Executor(int corePoolSize, final String queueName) {
super(
corePoolSize,
new ThreadFactory() {
private final ThreadFactory parent = Executors.defaultThreadFactory();
private final AtomicInteger tid = new AtomicInteger(1);
@Override
public Thread newThread(Runnable task) {
final Thread t = parent.newThread(task);
t.setName(queueName + "-" + tid.getAndIncrement());
t.setUncaughtExceptionHandler(WorkQueue::logUncaughtException);
return t;
}
});
all =
new ConcurrentHashMap<>( //
corePoolSize << 1, // table size
0.75f, // load factor
corePoolSize + 4 // concurrency level
);
this.queueName = queueName;
}
@Override
public void execute(Runnable command) {
super.execute(LoggingContext.copy(command));
}
@Override
public Future submit(Callable task) {
return super.submit(LoggingContext.copy(task));
}
@Override
public Future submit(Runnable task, T result) {
return super.submit(LoggingContext.copy(task), result);
}
@Override
public Future submit(Runnable task) {
return super.submit(LoggingContext.copy(task));
}
@Override
public List> invokeAll(Collection> tasks)
throws InterruptedException {
return super.invokeAll(tasks.stream().map(LoggingContext::copy).collect(toList()));
}
@Override
public List> invokeAll(
Collection> tasks, long timeout, TimeUnit unit)
throws InterruptedException {
return super.invokeAll(
tasks.stream().map(LoggingContext::copy).collect(toList()), timeout, unit);
}
@Override
public T invokeAny(Collection> tasks)
throws InterruptedException, ExecutionException {
return super.invokeAny(tasks.stream().map(LoggingContext::copy).collect(toList()));
}
@Override
public T invokeAny(Collection> tasks, long timeout, TimeUnit unit)
throws InterruptedException, ExecutionException, TimeoutException {
return super.invokeAny(
tasks.stream().map(LoggingContext::copy).collect(toList()), timeout, unit);
}
@Override
public ScheduledFuture schedule(Runnable command, long delay, TimeUnit unit) {
return super.schedule(LoggingContext.copy(command), delay, unit);
}
@Override
public ScheduledFuture schedule(Callable callable, long delay, TimeUnit unit) {
return super.schedule(LoggingContext.copy(callable), delay, unit);
}
@Override
public ScheduledFuture scheduleAtFixedRate(
Runnable command, long initialDelay, long period, TimeUnit unit) {
return super.scheduleAtFixedRate(LoggingContext.copy(command), initialDelay, period, unit);
}
@Override
public ScheduledFuture scheduleWithFixedDelay(
Runnable command, long initialDelay, long delay, TimeUnit unit) {
return super.scheduleWithFixedDelay(LoggingContext.copy(command), initialDelay, delay, unit);
}
@Override
protected void terminated() {
super.terminated();
queues.remove(this);
}
private void buildMetrics(String queueName) {
metrics.newCallbackMetric(
getMetricName(queueName, "max_pool_size"),
Long.class,
new Description("Maximum allowed number of threads in the pool")
.setGauge()
.setUnit("threads"),
() -> (long) getMaximumPoolSize());
metrics.newCallbackMetric(
getMetricName(queueName, "pool_size"),
Long.class,
new Description("Current number of threads in the pool").setGauge().setUnit("threads"),
() -> (long) getPoolSize());
metrics.newCallbackMetric(
getMetricName(queueName, "active_threads"),
Long.class,
new Description("Number number of threads that are actively executing tasks")
.setGauge()
.setUnit("threads"),
() -> (long) getActiveCount());
metrics.newCallbackMetric(
getMetricName(queueName, "scheduled_tasks"),
Integer.class,
new Description("Number of scheduled tasks in the queue").setGauge().setUnit("tasks"),
() -> getQueue().size());
metrics.newCallbackMetric(
getMetricName(queueName, "total_scheduled_tasks_count"),
Long.class,
new Description("Total number of tasks that have been scheduled for execution")
.setCumulative()
.setUnit("tasks"),
this::getTaskCount);
metrics.newCallbackMetric(
getMetricName(queueName, "total_completed_tasks_count"),
Long.class,
new Description("Total number of tasks that have completed execution")
.setCumulative()
.setUnit("tasks"),
this::getCompletedTaskCount);
}
private String getMetricName(String queueName, String metricName) {
String name =
CaseFormat.UPPER_CAMEL.to(
CaseFormat.LOWER_UNDERSCORE, queueName.replaceFirst("SSH", "Ssh").replace("-", ""));
return metrics.sanitizeMetricName(String.format("queue/%s/%s", name, metricName));
}
@Override
protected RunnableScheduledFuture decorateTask(
Runnable runnable, RunnableScheduledFuture r) {
r = super.decorateTask(runnable, r);
for (; ; ) {
final int id = idGenerator.next();
Task task;
if (runnable instanceof LoggingContextAwareRunnable) {
runnable = ((LoggingContextAwareRunnable) runnable).unwrap();
}
if (runnable instanceof ProjectRunnable) {
task = new ProjectTask<>((ProjectRunnable) runnable, r, this, id);
} else {
task = new Task<>(runnable, r, this, id);
}
if (all.putIfAbsent(task.getTaskId(), task) == null) {
return task;
}
}
}
@Override
protected RunnableScheduledFuture decorateTask(
Callable callable, RunnableScheduledFuture task) {
throw new UnsupportedOperationException("Callable not implemented");
}
void remove(Task task) {
all.remove(task.getTaskId(), task);
}
Task getTask(int id) {
return all.get(id);
}
void addAllTo(List> list) {
list.addAll(all.values()); // iterator is thread safe
}
Collection> getTasks() {
return all.values();
}
public void onStart(Task task) {
listeners.runEach(extension -> extension.getProvider().get().onStart(task));
}
public void onStop(Task task) {
listeners.runEach(extension -> extension.getProvider().get().onStop(task));
}
}
private static void logUncaughtException(Thread t, Throwable e) {
logger.atSevere().withCause(e).log("WorkQueue thread %s threw exception", t.getName());
}
/**
* Runnable needing to know it was canceled. Note that cancel is called only in case the task is
* not in progress already.
*/
public interface CancelableRunnable extends Runnable {
/** Notifies the runnable it was canceled. */
void cancel();
}
/**
* Base interface handles the case when task was canceled before actual execution and in case it
* was started cancel method is not called yet the task itself will be destroyed anyway (it will
* result in resource opening errors). This interface gives a chance to implementing classes for
* handling such scenario and act accordingly.
*/
public interface CanceledWhileRunning extends CancelableRunnable {
/** Notifies the runnable it was canceled during execution. * */
void setCanceledWhileRunning();
}
/** A wrapper around a scheduled Runnable, as maintained in the queue. */
public static class Task implements RunnableScheduledFuture {
/**
* Summarized status of a single task.
*
* Tasks have the following state flow:
*
*
* - {@link #SLEEPING}: if scheduled with a non-zero delay.
*
- {@link #READY}: waiting for an available worker thread.
*
- {@link #STARTING}: onStart() actively executing on a worker thread.
*
- {@link #RUNNING}: actively executing on a worker thread.
*
- {@link #STOPPING}: onStop() actively executing on a worker thread.
*
- {@link #DONE}: finished executing, if not periodic.
*
*/
public enum State {
// Ordered like this so ordinal matches the order we would
// prefer to see tasks sorted in: done before running,
// stopping before running, running before starting,
// starting before ready, ready before sleeping.
//
DONE,
CANCELLED,
STOPPING,
RUNNING,
STARTING,
READY,
SLEEPING,
OTHER
}
private final Runnable runnable;
private final RunnableScheduledFuture task;
private final Executor executor;
private final int taskId;
private final Instant startTime;
// runningState is non-null when listener or task code is running in an executor thread
private final AtomicReference runningState = new AtomicReference<>();
Task(Runnable runnable, RunnableScheduledFuture task, Executor executor, int taskId) {
this.runnable = runnable;
this.task = task;
this.executor = executor;
this.taskId = taskId;
this.startTime = Instant.now();
}
public int getTaskId() {
return taskId;
}
public State getState() {
if (isCancelled()) {
return State.CANCELLED;
}
State r = runningState.get();
if (r != null) {
return r;
} else if (isDone() && !isPeriodic()) {
return State.DONE;
}
final long delay = getDelay(TimeUnit.MILLISECONDS);
if (delay <= 0) {
return State.READY;
}
return State.SLEEPING;
}
public Instant getStartTime() {
return startTime;
}
public String getQueueName() {
return executor.queueName;
}
@Override
public boolean cancel(boolean mayInterruptIfRunning) {
if (task.cancel(mayInterruptIfRunning)) {
// Tiny abuse of runningState: if the task needs to know it
// was canceled (to clean up resources) and it hasn't started
// yet the task's run method won't execute. So we tag it
// as running and allow it to clean up. This ensures we do
// not invoke cancel twice.
//
if (runnable instanceof CancelableRunnable) {
if (runningState.compareAndSet(null, State.RUNNING)) {
((CancelableRunnable) runnable).cancel();
} else if (runnable instanceof CanceledWhileRunning) {
((CanceledWhileRunning) runnable).setCanceledWhileRunning();
}
}
if (runnable instanceof Future) {
// Creating new futures eventually passes through
// AbstractExecutorService#schedule, which will convert the Guava
// Future to a Runnable, thereby making it impossible for the
// cancellation to propagate from ScheduledThreadPool's task back to
// the Guava future, so kludge it here.
((Future) runnable).cancel(mayInterruptIfRunning);
}
executor.remove(this);
executor.purge();
return true;
}
return false;
}
@Override
public int compareTo(Delayed o) {
return task.compareTo(o);
}
@Override
public V get() throws InterruptedException, ExecutionException {
return task.get();
}
@Override
public V get(long timeout, TimeUnit unit)
throws InterruptedException, ExecutionException, TimeoutException {
return task.get(timeout, unit);
}
@Override
public long getDelay(TimeUnit unit) {
return task.getDelay(unit);
}
@Override
public boolean isCancelled() {
return task.isCancelled();
}
@Override
public boolean isDone() {
return task.isDone();
}
@Override
public boolean isPeriodic() {
return task.isPeriodic();
}
@Override
public void run() {
if (runningState.compareAndSet(null, State.STARTING)) {
String oldThreadName = Thread.currentThread().getName();
try {
executor.onStart(this);
runningState.set(State.RUNNING);
Thread.currentThread().setName(oldThreadName + "[" + task.toString() + "]");
task.run();
} finally {
Thread.currentThread().setName(oldThreadName);
runningState.set(State.STOPPING);
executor.onStop(this);
if (isPeriodic()) {
runningState.set(null);
} else {
runningState.set(State.DONE);
executor.remove(this);
}
}
}
}
@Override
public String toString() {
// This is a workaround to be able to print a proper name when the task
// is wrapped into a TrustedListenableFutureTask.
try {
if (runnable
.getClass()
.isAssignableFrom(
Class.forName("com.google.common.util.concurrent.TrustedListenableFutureTask"))) {
Class trustedFutureInterruptibleTask =
Class.forName(
"com.google.common.util.concurrent.TrustedListenableFutureTask$TrustedFutureInterruptibleTask");
for (Field field : runnable.getClass().getDeclaredFields()) {
if (field.getType().isAssignableFrom(trustedFutureInterruptibleTask)) {
field.setAccessible(true);
Object innerObj = field.get(runnable);
if (innerObj != null) {
for (Field innerField : innerObj.getClass().getDeclaredFields()) {
if (innerField.getType().isAssignableFrom(Callable.class)) {
innerField.setAccessible(true);
return innerField.get(innerObj).toString();
}
}
}
}
}
}
} catch (ClassNotFoundException | IllegalArgumentException | IllegalAccessException e) {
logger.atFine().log(
"Cannot get a proper name for TrustedListenableFutureTask: %s", e.getMessage());
}
return runnable.toString();
}
}
/**
* Same as Task class, but with a reference to ProjectRunnable, used to retrieve the project name
* from the operation queued
*/
public static class ProjectTask extends Task implements ProjectRunnable {
private final ProjectRunnable runnable;
ProjectTask(
ProjectRunnable runnable, RunnableScheduledFuture task, Executor executor, int taskId) {
super(runnable, task, executor, taskId);
this.runnable = runnable;
}
@Override
public Project.NameKey getProjectNameKey() {
return runnable.getProjectNameKey();
}
@Override
public String getRemoteName() {
return runnable.getRemoteName();
}
@Override
public boolean hasCustomizedPrint() {
return runnable.hasCustomizedPrint();
}
@Override
public String toString() {
return runnable.toString();
}
}
}