about Enum.values() memory allocation

[nezih yigitbasi]

Thanks Ron. Yes, working around this is pretty easy. But, it is a common
pattern to foreach over Enum.values(), so it would be nice if the
runtime/compiler handles that in a more efficient way.

Nezih

Ron Shapiro <ronshapiro at google.com>, 25 Tem 2018 Çar, 04:18 tarihinde şunu
yazdı:

> It's a bit of indirection, but can for (YourEnum e :
> EnumSet.allOf(YourEnum.class)) {} do the trick? It will still allocate, but
> likely only one instance instead of a full array.
>
> On Wed, Jul 25, 2018, 5:23 AM Michael Rasmussen <
> Michael.Rasmussen at roguewave.com> wrote:
>
>> With condy being added in Java 11, this could potentially be a use-case
>> for that ?
>>
>>
>> for (EnumType e: const(EnumType.values())) { ... }
>>
>>
>> Or perhaps it's time to add a List<E> valuesList(); to enum types, that
>> returns an immutable List of the values?
>>
>>
>> /Michael
>> ------------------------------
>> *From:* compiler-dev <compiler-dev-bounces at openjdk.java.net> on behalf
>> of nezih yigitbasi <nezihyigitbasi at gmail.com>
>> *Sent:* 25 July 2018 08:23:57
>> *To:* compiler-dev at openjdk.java.net
>> *Subject:* about Enum.values() memory allocation
>>
>> Hi,
>> I recently noticed in our app that Enum.values() allocates a significant
>> amount of memory when called in a tight loop as it clones the constant
>> values array (which is probably for immutability, and I can understand
>> that). I found that the same issue has been discussed back in 2012:
>> http://mail.openjdk.java.net/pipermail/compiler-dev/2012-March/004210.html
>>
>> Are there any plans to address this issue going forward?
>>
>> Thanks!
>>
>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.openjdk.java.net/pipermail/compiler-dev/attachments/20180725/76583cff/attachment.html>