Tom S Wrote: > Jeremie Pelletier wrote: > > Tom S Wrote: > > > >> Jeremie Pelletier wrote: > >>> I haven't had to use the C heap whatsoever so far in D, could you give me > >>> an example of where you need it? In fact, the *only* place I use the C > >>> heap is in my garbage collector's internals, for pool structs and mark > >>> ranges. I use pointers to GC memory all the time too, there are plenty of > >>> algorithms, especially in loops, that can run faster with pointer > >>> arithmetic than slices and it's still the fastest way to pass struct > >>> references around. > >> I use the C heap a lot when I need slabs of memory that the GC should > >> not look into for performance reasons. This includes images/textures, > >> mesh data and some data structures that I release manually - again, for > >> efficiency reasons. > > > > The garbage collector in D already mark allocations which contains pointers > > and scans these only. If you want to know if a type contains pointers, > > check the 'flags' property of the typeinfo or classinfo, test for bit0 and > > bit1 respectively. This is what the GC uses at runtime when allocating > > memory to know if it should tag the allocation as containing possible > > pointers. > > Yea I know, but I want structures with pointers manually managed as well.
Then just inform the GC to not scan the allocations you want, or better yet have a static ctor modify the flag of the typeinfo you don't want scanned. > > I myself allocate all my meshes and textures directly on the GC and I'm > > pretty sure its faster than C's malloc and much safer. > > Hm, why would it be faster with the GC than malloc? I'm pretty sure it's > the opposite :P Plus, I could use a specialized malloc implementation, > like TLSF. The D GC is already specialized, and given its being used quite a lot in D, there are good chances its already sitting in the CPU cache, its heap already having the available memory block waiting on a freelist, or if the alloc is more than 0x1000 bytes, the pages available in a pool. You'd need to use malloc quite a lot to get the same optimal performance, and mixing the two would affect the performance of both. > >>>> - I like how D doesn't totally ignore safety as C does, in D sometimes > >>>> the default way is the safer one, and the unsafe way is used only where > >>>> you ask for it. I'd like to see more safeties added to D, like optional > >>>> run-time and compile-time integral overflow tests, some pointer safety, > >>>> better template error messages (template constraints help some in such > >>>> regard), stack traces, less compiler bugs, safer casts (in C# you need > >>>> explicit casts to convert double => float), a safer printf, some > >>>> optional annotations inspired by Plint (a lint program) to give more > >>>> semantics to the compiler, that can be used to both speed up code and > >>>> avoid bugs. There's lot that can be done in this regard. And > >>>> release-mode performance can be usually kept unchanged. > >>> Stack traces is a feature for the runtime, I made one for mine, which > >>> shows a dialog window with the stack trace, current registers values, > >>> loaded modules and whatnot. Took me almost a week to piece together my > >>> CodeView reader, I still need a DWARF reader for linux. I'm gonna try and > >>> implement it in druntime and submit the patch to bugzilla. > >> Tango's runtime already does stack tracing on Windows and *NIX, however > >> its CV parser is subject to some licensing issues :( Perhaps you could > >> release yours under some liberal license so it can be plugged there? :) > >> > > > > Sure, I wouldn't mind at all, I'm not into licenses myself so I might just > > release it to public domain. I'll try and get a standalone package ready > > and post it somewhere, I just don't know where yet :x > > Sweet :D As for a place, there are plenty of options, e.g. > http://dsource.org/projects/scrapple/ or a separate dsource project. I thought of that, but I don't feel like opening a project for just a few random code snippets or standalone classes. I think I'll just post it in this forum and let interested people grab it for now.
