53 lines
1.5 KiB
Java
53 lines
1.5 KiB
Java
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//: concurrency/SimplePriorities.java
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// <20>2015 MindView LLC: see Copyright.txt
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// Shows thread priorities.
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import java.util.concurrent.*;
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public class SimplePriorities implements Runnable {
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private int countDown = 5;
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private volatile double d; // No optimization
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private int priority;
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public SimplePriorities(int priority) {
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this.priority = priority;
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}
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@Override
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public String toString() {
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return Thread.currentThread() + ": " + countDown;
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}
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@Override
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public void run() {
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Thread.currentThread().setPriority(priority);
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while(true) {
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// An expensive, interruptable operation:
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for(int i = 1; i < 100000; i++) {
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d += (Math.PI + Math.E) / (double)i;
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if(i % 1000 == 0)
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Thread.yield();
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}
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System.out.println(this);
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if(--countDown == 0) return;
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}
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}
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public static void main(String[] args) {
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ExecutorService exec = Executors.newCachedThreadPool();
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for(int i = 0; i < 5; i++)
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exec.execute(
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new SimplePriorities(Thread.MIN_PRIORITY));
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exec.execute(
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new SimplePriorities(Thread.MAX_PRIORITY));
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exec.shutdown();
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}
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} /* Output: (First 10 Lines)
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Thread[pool-1-thread-6,10,main]: 5
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Thread[pool-1-thread-1,1,main]: 5
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Thread[pool-1-thread-4,1,main]: 5
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Thread[pool-1-thread-5,1,main]: 5
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Thread[pool-1-thread-3,1,main]: 5
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Thread[pool-1-thread-2,1,main]: 5
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Thread[pool-1-thread-3,1,main]: 4
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Thread[pool-1-thread-5,1,main]: 4
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Thread[pool-1-thread-4,1,main]: 4
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Thread[pool-1-thread-1,1,main]: 4
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...
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*///:~
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