io.micronaut.scheduling.ReschedulingTask Maven / Gradle / Ivy
/*
* Copyright 2017-2018 original authors
*
* 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 io.micronaut.scheduling;
import io.micronaut.scheduling.exceptions.TaskExecutionException;
import java.time.Duration;
import java.util.concurrent.Callable;
import java.util.concurrent.Delayed;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.function.Supplier;
/**
* Wraps a {@link Runnable} and re-schedules the tasks.
*
* @param The result type returned by this Future
*
* @author graemerocher
* @since 1.0
*/
class ReschedulingTask implements ScheduledFuture, Runnable, Callable {
private final Callable task;
private final TaskScheduler taskScheduler;
private final Supplier nextTime;
private ScheduledFuture currentFuture;
private AtomicBoolean cancelled = new AtomicBoolean(false);
/**
* @param task The task
* @param taskScheduler To schedule the task for next time
* @param nextTime The next time
*/
ReschedulingTask(Callable task, TaskScheduler taskScheduler, Supplier nextTime) {
this.task = task;
this.taskScheduler = taskScheduler;
this.nextTime = nextTime;
this.currentFuture = taskScheduler.schedule(nextTime.get(), (Callable) this);
}
@Override
public V call() throws Exception {
try {
return task.call();
} finally {
synchronized (this) {
if (!cancelled.get()) {
this.currentFuture =
taskScheduler.schedule(nextTime.get(), (Callable) this);
}
}
}
}
@Override
public void run() {
try {
call();
} catch (Exception e) {
throw new TaskExecutionException("Error executing task: " + e.getMessage(), e);
}
}
@Override
public long getDelay(TimeUnit unit) {
ScheduledFuture current;
synchronized (this) {
current = this.currentFuture;
}
return current.getDelay(unit);
}
@Override
public int compareTo(Delayed o) {
ScheduledFuture current;
synchronized (this) {
current = this.currentFuture;
}
return current.compareTo(o);
}
@Override
public boolean cancel(boolean mayInterruptIfRunning) {
ScheduledFuture current;
synchronized (this) {
cancelled.set(true);
current = this.currentFuture;
}
return current.cancel(mayInterruptIfRunning);
}
@Override
public boolean isCancelled() {
return cancelled.get();
}
@Override
public boolean isDone() {
synchronized (this) {
return this.currentFuture.isDone();
}
}
@Override
public V get() throws InterruptedException, ExecutionException {
ScheduledFuture current;
synchronized (this) {
cancelled.set(true);
current = this.currentFuture;
}
return (V) current.get();
}
@Override
public V get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
ScheduledFuture current;
synchronized (this) {
cancelled.set(true);
current = this.currentFuture;
}
return (V) current.get(timeout, unit);
}
}