gc vs explicit

[Sean Kelly]

Dave wrote:
> Sean Kelly wrote:
>> zz wrote:
>>> Dave wrote:
>>>> zz wrote:
>>>>
>>>>> Walter Bright wrote:
>>>>>
>>>>>> zz wrote:
>>>>>>
>>>>>>>  From my point of view these tests are not really nessesary on my 
>>>>>>> side since I still continue using D and I belive that someday the 
>>>>>>> memory stuff will be optimized.
>>>>>>
>>>>>>
>>>>>>
>>>>>> One thing that is happening is that the C++ code allocates memory, 
>>>>>> it never frees it. The same with the D code.
>>>>>
>>>>>
>>>>> Not until it's out of scope (in this case main).
>>>>>
>>>>
>>>> With that in mind, I wrapped your original code in a loop for 10 
>>>> iterations and decreased the inner loop to 100000.
>>>>
>>>> C++ (NedAlloc):
>>>> Total Element count: 1000000
>>>> 5.438000
>>>>
>>>> D:
>>>> Total Element count: 1000000
>>>> 1.360000
>>>>
>>> Cant' argue with that:
>>> In this case D is faster I get:
>>> C++ NedAlloc = 2.859
>>> D = 1.421
>>>
>>> But if you leave the original count and put in the outer loop for 10, 
>>> D's performance becomes really bad.
>>>
>>> c++ (NedMalloc) = 00:26.796
>>> D = 02:23.375
>>
>> Try explicitly calling _gc.fullCollect() between iterations of the 
>> inner loop, and disabling the GC explicitly there.  Manipulation of 
>> the GC for performance-critical areas is an important and intentional 
>> feature.
>>
> 
> With that in mind... What if some of the GC API were built-in to the 
> language? This could be one of those areas that would set D apart as a 
> lower-level, performance orientated language. If a GC implementation 
> didn't support something, it would be stubbed for portability. Likewise 
> anything not covered explicitly by a built-in could be covered by an 
> import.
> 
> Specifically:
> 
> gcFullCollect()
> gcGenCollect()
> gcDisable()
> gcEnable()
> 
> or some such.

Phobos already has std.gc for exactly this purpose.  Or are you 
suggesting some of these features should be added as keywords, or 
perhaps automatically available, similar to the declaration of Object 
and Exception?


Sean