On 23 September 2013 14:17, Nicolas Cellier
<[email protected]> wrote:
> Here is my 100% personal opinion:
>
> I don't like the copyShuffle.
> To me, the rules are quite clear:
> sort shuffle reverse etc... -> perform modification in place
> sorted shuffled reversed etc... -> answer a copy
> I hope the methods comments are clear. Does PBE tells about these
> conventions? It would be a good thing.
>
> And I don't like to have mutexes in base library, the less we have, the
> better.
> If a user is going to modify the same object concurrently, he/she takes care
> of mutual exclusion.

Especially since locks don't compose. If you _really_ cared about
accessing something concurrently, you'd share immutable data
structures.

frank

> 2013/9/23 Max Leske <[email protected]>
>>
>> Sven suggested posting this on the list for discussion, so here you go:
>>
>> Maybe this should be discussed on the list, your are going to break API.
>>
>> Note that there is also #sort and #sorted with similar copy behavior.
>>
>> Also, I am not sure that basic operations should use mutexes to protect
>> themselves by default: there is a cost when you are a single threaded user.
>> Even in Java there are synchronized and non-synchronized versions of
>> collections. IMHO, the protection should happen in your app, and basic
>> collections do not have to be thread safe.
>>
>> Sven
>>
>> #shuffle does not use Collection>>mutexForPicking as other users of
>> #randomForPicking demonstrate. This can lead to race conditions (found in
>> our application).
>>
>> In addition, there are now #shuffle, #shuffled, #shuffleBy: and
>> #shuffledBy: where #shuffled and #shuffledBy: shuffle a copy and answers
>> that. This is very confusing.
>>
>> I propose a fix where #shuffled and #shuffledBy: are renamed to
>> #copyShuffle and #copyShuffledBy: and moved to the "copying" protocol.
>> #shuffle and #copyShuffle will use the mutex to prevent race conditions.
>
>

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