44 lines
998 B
Java
44 lines
998 B
Java
// concurrent/SharedConstructorArgument.java
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// (c)2021 MindView LLC: see Copyright.txt
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// We make no guarantees that this code is fit for any purpose.
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// Visit http://OnJava8.com for more book information.
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import java.util.concurrent.atomic.*;
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interface SharedArg {
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int get();
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}
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class Unsafe implements SharedArg {
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private int i = 0;
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@Override public int get() { return i++; }
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}
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class Safe implements SharedArg {
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private static AtomicInteger counter =
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new AtomicInteger();
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@Override public int get() {
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return counter.getAndIncrement();
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}
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}
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class SharedUser implements HasID {
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private final int id;
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SharedUser(SharedArg sa) {
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id = sa.get();
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}
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@Override public int getID() { return id; }
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}
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public class SharedConstructorArgument {
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public static void main(String[] args) {
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Unsafe unsafe = new Unsafe();
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IDChecker.test(() -> new SharedUser(unsafe));
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Safe safe = new Safe();
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IDChecker.test(() -> new SharedUser(safe));
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}
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}
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/* Output:
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16537
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0
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*/
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