com.hazelcast.spi.TaskScheduler Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2017, Hazelcast, Inc. All Rights Reserved.
*
* 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.hazelcast.spi;
import java.util.concurrent.Callable;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
/**
* {@link ExecutorService} can schedule a command to run after a given delay or execute periodically.
*
* The {@link #scheduleWithRepetition(Runnable, long, long, TimeUnit)} has similar semantic
* to {@link java.util.concurrent.ScheduledExecutorService#scheduleAtFixedRate(Runnable, long, long, TimeUnit)}. It
* guarantees a task won't be executed by multiple threads concurrently. The difference is that this service will
* skip a scheduled execution if another thread is still running the same task, instead of postponing its execution.
* To emphasize this difference the method is called scheduleAtFixedRate
* instead of scheduleAtFixedRate
*
* The other difference is this service does not offer an equivalent of
* {@link java.util.concurrent.ScheduledExecutorService#scheduleWithFixedDelay(Runnable, long, long, TimeUnit)}
*
*/
public interface TaskScheduler extends Executor {
/**
* Creates and executes a one-shot action that becomes enabled
* after the given delay.
*
* @param command the task to execute
* @param delay the time from now to delay execution
* @param unit the time unit of the delay parameter
* @return a ScheduledFuture representing pending completion of
* the task and whose {@code get()} method will return
* {@code null} upon completion
* @throws RejectedExecutionException if the task cannot be
* scheduled for execution
* @throws NullPointerException if command is null
*/
ScheduledFuture schedule(Runnable command, long delay, TimeUnit unit);
/**
* Creates and executes a one-shot action that becomes enabled
* after the given delay.
*
* @param command the task to execute
* @param delay the time from now to delay execution
* @param unit the time unit of the delay parameter
* @return a ScheduledFuture representing pending completion of
* the task and whose {@code get()} method will return
* {@code } upon completion
* @throws RejectedExecutionException if the task cannot be
* scheduled for execution
* @throws NullPointerException if command is null
*/
ScheduledFuture> schedule(Callable command, long delay, TimeUnit unit);
/**
* Creates and executes a periodic action that becomes enabled first
* after the given initial delay, and subsequently with the given
* period. Executions will commence after
* {@code initialDelay} then {@code initialDelay+period}, then
* {@code initialDelay + 2 * period}, and so on.
* If any execution of this task
* takes longer than its period, then subsequent execution will be skipped.
*
* @param command the task to execute
* @param initialDelay the time to delay first execution
* @param period the period between successive executions
* @param unit the time unit of the initialDelay and period parameters
* @return a ScheduledFuture representing pending completion of
* the task, and whose {@code get()} method will throw an
* exception upon cancellation
* @throws RejectedExecutionException if the task cannot be
* scheduled for execution
* @throws NullPointerException if command is null
* @throws IllegalArgumentException if period is less than or equal to zero
*/
ScheduledFuture scheduleWithRepetition(Runnable command, long initialDelay, long period, TimeUnit unit);
}