67 lines
2.5 KiB
Java
67 lines
2.5 KiB
Java
/*
|
|
* Copyright 2016 The Netty Project
|
|
*
|
|
* The Netty Project licenses this file to you 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.netty.util.concurrent;
|
|
|
|
import io.netty.util.internal.ObjectUtil;
|
|
|
|
import java.util.concurrent.RejectedExecutionException;
|
|
import java.util.concurrent.TimeUnit;
|
|
import java.util.concurrent.locks.LockSupport;
|
|
|
|
/**
|
|
* Expose helper methods which create different {@link RejectedExecutionHandler}s.
|
|
*/
|
|
public final class RejectedExecutionHandlers {
|
|
private static final RejectedExecutionHandler REJECT = (task, executor) -> {
|
|
throw new RejectedExecutionException();
|
|
};
|
|
|
|
private RejectedExecutionHandlers() { }
|
|
|
|
/**
|
|
* Returns a {@link RejectedExecutionHandler} that will always just throw a {@link RejectedExecutionException}.
|
|
*/
|
|
public static RejectedExecutionHandler reject() {
|
|
return REJECT;
|
|
}
|
|
|
|
/**
|
|
* Tries to backoff when the task can not be added due restrictions for an configured amount of time. This
|
|
* is only done if the task was added from outside of the event loop which means
|
|
* {@link EventExecutor#inEventLoop()} returns {@code false}.
|
|
*/
|
|
public static RejectedExecutionHandler backoff(final int retries, long backoffAmount, TimeUnit unit) {
|
|
ObjectUtil.checkPositive(retries, "retries");
|
|
final long backOffNanos = unit.toNanos(backoffAmount);
|
|
return (task, executor) -> {
|
|
if (!executor.inEventLoop()) {
|
|
for (int i = 0; i < retries; i++) {
|
|
// Try to wake up the executor so it will empty its task queue.
|
|
executor.wakeup(false);
|
|
|
|
LockSupport.parkNanos(backOffNanos);
|
|
if (executor.offerTask(task)) {
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
// Either we tried to add the task from within the EventLoop or we was not able to add it even with
|
|
// backoff.
|
|
throw new RejectedExecutionException();
|
|
};
|
|
}
|
|
}
|