Java AtomicLong weakCompareAndSet() Method

The weakCompareAndSet() method of java AtomicLong class atomically sets the value to the given updated value if the current value is equal to the expected value. May fail spuriously and does not provide ordering guarantees, so is only rarely an appropriate alternative to compareAndSet.

Syntax

@Deprecated(since="9")
	public final boolean weakCompareAndSet(long expectedValue,
                                       long newValue)

Parameters

expectedValue - the expected value

newValue - the new value

Returns

true if successful

Example 1

import java.util.concurrent.atomic.AtomicLong;
public class AtomicLongWeakCompareAndSetExample1 {
	public static void main (String [] args) {
		AtomicLong atomiclong = new AtomicLong();
		long expectedValue = 0;
		long newValue = 111;
		atomiclong.weakCompareAndSet(expectedValue, newValue);
		//Since Initialized value and expected value are equal prints the new value
		System.out.println(atomiclong);
	}
}

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Output:

Example 2

import java.util.concurrent.atomic.AtomicLong;
public class AtomicLongWeakCompareAndSetExample2 {
public static void main (String [] args) {
		AtomicLong atomiclong = new AtomicLong();
		long expectedValue = 222;
		long newValue = 111;
		atomiclong.weakCompareAndSet(expectedValue, newValue);
		//Since Initialized value and expected value are not equal prints the Initialized value
		System.out.println(atomiclong);
	}
}

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Output:

Example 3

import java.util.concurrent.atomic.AtomicLong;
public class AtomicLongWeakCompareAndSetExample3 {
	public static void main (String [] args) {
		AtomicLong atomiclong = new AtomicLong(222);
		long expectedValue = 222;
		long newValue = -45;
		atomiclong.weakCompareAndSet(expectedValue, newValue);
		//Since Initialized value and expected value are equal prints the New value
		System.out.println(atomiclong);
	}
}

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Output:

-45

Example 4

import java.util.concurrent.atomic.AtomicLong;
public class AtomicLongWeakCompareAndSetExample4 {
	public static void main (String [] args) {
		AtomicLong atomiclong = new AtomicLong(-10);
		long expectedValue = 10;
		long newValue = -20;
		atomiclong.weakCompareAndSet(expectedValue, newValue);
		//Since Initialized value and expected value are not equal prints the Initialized value
		System.out.println(atomiclong);
	}
}

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Output: