In article <djvt02$1a1b$1@digitaldaemon.com>, Dave says...
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>In article <djtcfe$1qr4$1@digitaldaemon.com>, Tomás Rossi says...
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>>In article <djs827$jjj$1@digitaldaemon.com>, Dave says...
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>>>In article <djs1hd$dkv$1@digitaldaemon.com>, Tomás Rossi says...
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>>>>In article <djrbki$la6$1@digitaldaemon.com>, James Dunne says...
>>>>>
>>>>>Tomás Rossi wrote:
>>>>>> In article <djjic8$1ipg$2@digitaldaemon.com>, Walter Bright says...
>>>>>> 
>>>>>>>
>>>>>>>"Tomás Rossi" <Tomás_member@pathlink.com> wrote in message news:djj8qd$1ain$1@digitaldaemon.com...
>>>>>>>
>>>>>>>>Is there a way to turn off the GC (Garbage Collector) in D?
>>>>>>>
>>>>>>>Sure. www.digitalmars.com/d/phobos/std_gc.html
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>What if I want to manage all the memory by myself? Is this possible?
>>>>>>>
>>>>>>>Yes. You can even use C's malloc/free. See www.digitalmars.com/d/memory.html
>>>>>>>
>>>>>>>
>>>>>> 
>>>>>> 
>>>>>> When disabling GC (std.gc.disable()) I just inhibit the GC cycles but, what if I
>>>>>> refuse to use the GC at all? what if I DON´T WANT the GC to be compiled with my
>>>>>> program and still wan´t to use new & delete operators, just like C++? (some kind
>>>>>> of conditional GC), can I do that?
>>>>>> 
>>>>>> Sorry for my ignorance, I'm already loving this language though...
>>>>>> 
>>>>>> Tom
>>>>>
>>>>>I wrote a phobos patch way back in the long-long ago that's probably outdated now... but it is theoretically a very simple patch.  It simply ripped out the GC implementation and used C's malloc and free; naively I might add.  Most of phobos is coded with use of the GC in mind, and is quite memory-leaky without it.  All the GC related code is in src/phobos/internal/gc/.
>>>>
>>>>So, I'm tied to use GC if I want to take advantage of any of the Phobos benefits. GC will be there, compiled with the rest no matter if I use it or not. :'( that's so sad. I must admit i have issues... DON'T FULLY TRUST GARBAGE COLLECTORS YET.
>>>>
>>>>On the other hand, i'm wondering, if D is a language that claims it can be used to write OSs (we all know OS code, or much of it, need to be very efficient), i dont think using GC in this code would be such a good idea. Probably OS would yet be implemented with malloc/free, because that way, you still have "some" control on what it happens... Ok, there is my mistrust in GC again. :P
>>>>
>>>>Regards
>>>>
>>>>Tom
>>>
>>>Well, as stated before, with D you can use malloc/free as much as you want and even develop a lib. with non-GC'd functions when it makes sense (and take advantage of the GC for the rest) or for that matter just use C libraries when needed. With other contemporary languages like C# and Java you're much more limited in this area.
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>>>I used to feel the same about the GC as you do, but have come around to believe that a good GC can perform really well if the programmer doesn't abuse it.
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>>>The primary problem with Java and .Net software is that the GC *makes* it easy to 'abuse' and also because of some language of their features like not allowing OOP UDT's to be allocated on the stack as C++ and D do.
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>>Do you mean that not allowing you to allocate your objects in the stack is the abuse? Is there another way you can abuse of GC?
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>Well, that's part of it - just about everything has to be allocated on the heap, but in C++ you can allocate class objects on the stack and D you can use structs for some OOP features (and you can in C# too). Most of the "abuse" is just because the GC makes it easy to "allocate and forget" about managing resources. I suppose this will happen with any GC, but with Java it's really been hard on its performance reputation.
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>>>Don't take my word for it - get a Java or C# implementation with a mature allocator/GC system and benchmark allocating a bunch of strings and UDT objects with it, and then do the same with equivalent (heap alloc) code in C++. In many cases, the GC will perform at least as well -- even when enough memory is allocated to force a couple of GC's during the test.
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>>I don't know if i can benchmark a compiled language (C++) vs. an intepreted one (like C# or Java). I mean, i really don't know if the results will really help me to extract any conclusions. Even though the comparisons between a GCd language and a non-GCd one would be done in that case, i wouldn't really know when the differences would be caused by GC or by the intrinsic efficiency due to compiled/interpreted nature of each language.
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>JIT's are getting pretty good, and since your dealing with heap allocation that will be the bottleneck so the comparison will tell you more about the allocator/GC than the machine code optimizations.
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>>>D's GC is non-sophisticated because it is immature,
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>>I didn't know this... but now that you warned me, i have to tell you: "that makes me feel so relieved!" :P
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>>>but it'll improve to the
>>>level of the Java and C# GC's, probably very quickly after D 1.0 is released if
>>>not sooner.
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>>Hope so.
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>>>Besides, D has things like stack-allocated UDT's, easy array slicing, overrideable new/delete and de/allocators and copy-on-write library functions that make things a lot easier on a GC than Java and/or .Net; so a slow GC is less likely to cause as many problems.
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>>Ok, i know i'm a little paranoid and obsessive about efficiency when
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>That's a good thing IMHO - I think "slowness" is a "bug" and usually a lot harder to fix than most other bugs once a large program is getting close to being done. Users complain about crashes, but they *bitch* about slowness <g>
>
>>programming, but all the other very nice features of D that you're referring to are just the ones that i like very much and that's why i'm worried about the features that makes me "distrust" of the language performance (e.g. the GC). I have no doubts i will make use of it (the GC) in the most of my future D projects, but it would be SO NICE if it could be completely turned off in a transparent way for other kind of projects (and also have a non-GC-based Phobos, i know this will not happen, it's an utopia, but luckily dreaming is still free) :D.
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>>Regards
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>>
>>
>>Tom


So, if I explicitly delete my objects most of the times, that would be a wise use of GC? (namely that would be non-abusive use of GC?).

Tom