<i18n dev> RFR: 8345668: ZoneOffset.ofTotalSeconds performance regression [v3]

[Shaojin Wen]

On Fri, 20 Dec 2024 23:46:57 GMT, Naoto Sato <naoto at openjdk.org> wrote:

>> For example:
>> 
>> static final AtomicReferenceArray<ZoneOffset> MINUTES_15_CACHE = new AtomicReferenceArray<>(37 * 4);
>> 
>>     public static ZoneOffset ofTotalSeconds(int totalSeconds) {
>>         // ...
>>         int minutes15Rem = totalSeconds / (15 * SECONDS_PER_MINUTE);
>>         if (totalSeconds - minutes15Rem * 15 * SECONDS_PER_MINUTE == 0) {
>>             int cacheIndex = minutes15Rem + 18 * 4;
>>             ZoneOffset result = MINUTES_15_CACHE.get(cacheIndex);
>>             if (result == null) {
>>                 result = new ZoneOffset(totalSeconds);
>>                 if (!MINUTES_15_CACHE.compareAndSet(cacheIndex, null, result)) {
>>                     result = MINUTES_15_CACHE.get(minutes15Rem);
>>                 }
>>             }
>>             return result;
>>         }
>>        // ...
>>     }
>
> Hi Shaojin,
> Thanks for the suggestion, but I am not planning to improve the code more than backing out the offending fix at this time. (btw, cache size would be 149 as 18:00 and -18:00 are inclusive)

Can I submit a PR to make this improvement?

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/22854#discussion_r1894509276