/*_############################################################################
  _## 
  _##  SNMP4J - WorkerPool.java  
  _## 
  _##  Copyright (C) 2003-2026  Frank Fock (SNMP4J.org)
  _##  
  _##  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 org.snmp4j.util;

/**
 * The {@code WorkerPool} interface models an abstract pool of workers
 * (threads) which can execute {@link WorkerTask}s concurrently.
 *
 * @author Frank Fock
 * @version 1.9
 */
public interface WorkerPool {

    /**
     * Executes a task on behalf of this worker pool. If all threads are currently
     * busy, this method call blocks until a worker gets idle again which is when
     * the call returns immediately.
     * @param task
     *    a {@code Runnable} to execute.
     */
    void execute(WorkerTask task);

    /**
     * Tries to execute a task on behalf of this worker pool. If all threads are
     * currently busy, this method returns {@code false}. Otherwise the task
     * is executed in background.
     * @param task
     *    a {@code Runnable} to execute.
     * @return
     *    {@code true} if the task is executing.
     */
    boolean tryToExecute(WorkerTask task);

    /**
     * Stops all threads in this worker pool gracefully. This method will not
     * return until all threads have been terminated and joined successfully.
     */
    void stop();

    /**
     * Cancels all threads non-blocking by interrupting them.
     */
    void cancel();

    /**
     * Checks if all workers of the pool are idle.
     * @return
     *    {@code true} if all workers are idle.
     */
    boolean isIdle();

}
