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/****************************************************************************
Copyright 2007, Colorado School of Mines and others.
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 edu.mines.jtk.util;
/**
* Utilities for working with multiple threads.
* @author Dave Hale, Colorado School of Mines
* @version 2007.07.27
*/
public class Threads {
/**
* Gets the number of available processors (cores).
* @return the number of available processors (cores).
*/
public static int getAvailableProcessors() {
return Runtime.getRuntime().availableProcessors();
}
/**
* Returns a new array for threads. The length of the array equals the
* number of available processors (or cores).
*
* Note that this method does not actually construct any threads.
* @return the array.
*/
public static Thread[] makeArray() {
return makeArray(1);
}
/**
* Returns a new array for threads. The length of the array is greater
* than zero and is proportional to the number of available processors
* (or cores).
*
* Note that this method does not actually construct any threads.
* @param multiple desired number of threads per processor (or core).
* @return the array, with length for at least one thread.
*/
public static Thread[] makeArray(double multiple) {
int nprocessors = getAvailableProcessors();
int nthread = Math.max(1,(int)(multiple*nprocessors));
return new Thread[nthread];
}
/**
* Starts and joins all threads in the specified array.
* @param threads array of threads.
* @exception RuntimeException if any threads are interrupted.
*/
public static void startAndJoin(Thread[] threads) {
for (Thread thread:threads)
thread.start();
try {
for (Thread thread:threads)
thread.join();
} catch (InterruptedException ie) {
throw new RuntimeException(ie);
}
}
}