AtomicCounter release/acquire methods #315
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Jan 20, 2025
| @@ -330,27 +435,51 @@ public boolean compareAndSet(final long expectedValue, final long updateValue) | |||
| } | |||
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| /** | |||
| * Get the latest value for the counter with volatile semantics. | |||
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I have removed 'latest' because it implies that you will see the latest value. This isn't true. A correctly synchronized program will only show sequential consistent executions, and for sequential consistency, the real time order doesn't need to respected. For that you need linearizability.
The JVM will guarantee visibility, so it will promise that a value is seen eventually (but not immediately).
Unfortunately 'latest' is frequently mentioned even by JMM experts, but it isn't correct.
To make this PR less contentious.
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For all ordered methods, there is now a release variant. The ordered method will call the release version, so there is a slight performance penalty to pay.
Also getAcquire has been added since that normally is used in combination with a release method.