If I had my way

[Hans Uhlig]

On 12/11/2011 11:32 AM, Andrei Alexandrescu wrote:
> On 12/11/11 12:17 PM, Chad J wrote:
>> On 12/11/2011 11:21 AM, Andrei Alexandrescu wrote:
>>> On 12/11/11 9:14 AM, Chad J wrote:
>>>>
>>>> I think one thing that could would be (optional) reference counting for
>>>> transitively atomic types. Of course, this is just another kind of
>>>> garbage collection, but it is /deterministic/ and parallelizes well,
>>>> and
>>>> I bet this would open up a large amount of Phobos while the
>>>> stop-the-world collector is offline, and with little or no code change.
>>>
>>> I think the language has enough (in theory) and nearly enough (in
>>> practice) expressiveness to implement reference counted classes in a
>>> library, virtually transparently. I mean one could define a template
>>> RefCounted (an extended version of what's now in std) such that this
>>> pattern is possible:
>>>
>>> // client code
>>> class WidgetImpl {
>>> ...
>>> }
>>>
>>> alias RefCounted!WidgetImpl Widget;
>>>
>>> Aside from using WidgetImpl in type relationships, using Widget would
>>> transparently insert the appropriate reference counting without
>>> otherwise interfering with normal WidgetImpl semantics.
>>>
>>>
>>> Andrei
>>
>> This is good. So stick it in the runtime and make the compiler emit
>> RefCounted!___ templates whenever it finds a transitively atomic type.
>>
>> This can be done alongside the existing garbage collector.
>>
>> Then we can benchmark different combinations of memory management
>> strategies.
>>
>> Two compiler flags can work in tandem:
>> -nogc
>> -norefcount
>>
>> (Turn them both off if you really want to break Phobos.)
>
> We considered that route, and concluded it's marred by too many issues.
>
> Andrei
>

What issues did it cause?