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digitalmars.D - Allocator troubles

reply =?UTF-8?B?THXDrXM=?= Marques <luis luismarques.eu> writes:
I'm not having success trying to use the allocator API.

What am doing wrong here? (OS X, 64-bit)

     void main()
     {
         import std.exception;
         import std.experimental.allocator;
         import std.experimental.allocator.building_blocks.region;
         import std.stdio;

         static InSituRegion!1024 ralloc;
         IAllocator alloc = allocatorObject(&ralloc);

         enforce(alloc.make!int !is null);
         enforce(alloc.deallocateAll());

         enforce(alloc.make!int !is null);
         writeln("OK 1");

         enforce(alloc.deallocateAll());
         writeln("OK 2");
     }

     $ rdmd -g test.d
     OK 1
     Segmentation fault: 11


BTW, there doesn't seem to be any primitive like tryMake or an 
allocator building block that throws instead of returning null. I 
wanted to just replace my "new X" statements with a region 
allocator and leave the rest unchanged, so I had to create my own 
tryMake which wraps make calls with an enforcement of !is null. I 
was surprised by this omission (or did I miss something?). BTW, 
notice that I don't ever expect my allocator to return null 
unless there is a bug in my program, since the amount of memory 
needed is statically computed and carefully used, so it makes a 
lot of sense for me to just throw OutOfMemoryException.
Jul 15 2016
next sibling parent reply =?UTF-8?B?THXDrXM=?= Marques <luis luismarques.eu> writes:
On Friday, 15 July 2016 at 18:44:26 UTC, Luís Marques wrote:

 I'm not having success trying to use the allocator API.

 What am doing wrong here? (OS X, 64-bit)

 [...]


Given the lack of feedback, I'm going to assume it's a bug.
https://issues.dlang.org/show_bug.cgi?id=16285
Jul 16 2016
parent reply Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
On 07/16/2016 10:23 AM, Luís Marques wrote:

 On Friday, 15 July 2016 at 18:44:26 UTC, Luís Marques wrote:

 I'm not having success trying to use the allocator API.

 What am doing wrong here? (OS X, 64-bit)

 [...]


 Given the lack of feedback, I'm going to assume it's a bug.
 https://issues.dlang.org/show_bug.cgi?id=16285


I reproduced this on Linux and looked around a bit. It's pretty vexing. 
Thanks for submitting it. -- Andrei
Jul 16 2016
parent reply Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
On 07/16/2016 12:07 PM, Andrei Alexandrescu wrote:

 On 07/16/2016 10:23 AM, Luís Marques wrote:

 On Friday, 15 July 2016 at 18:44:26 UTC, Luís Marques wrote:

 I'm not having success trying to use the allocator API.

 What am doing wrong here? (OS X, 64-bit)

 [...]


 Given the lack of feedback, I'm going to assume it's a bug.
 https://issues.dlang.org/show_bug.cgi?id=16285


 I reproduced this on Linux and looked around a bit. It's pretty vexing.
 Thanks for submitting it. -- Andrei


Found the problem. Currently allocatorObject allocates the 
CAllocatorImpl object (interface implementation) straight inside the 
given allocator, in an ouroboros fashion. Subsequently, deallocateAll 
deallocates he CAllocatorImpl itself.

CAllocatorImpl!(A, Yes.indirect) allocatorObject(A)(A* pa)
{
     assert(pa);
     import std.conv : emplace;
     auto state = pa.allocate(stateSize!(CAllocatorImpl!(A, Yes.indirect)));
     import std.traits : hasMember;
     static if (hasMember!(A, "deallocate"))
     {
         scope(failure) pa.deallocate(state);
     }
     return emplace!(CAllocatorImpl!(A, Yes.indirect))
         (state, pa);
}



Andrei
Jul 16 2016
parent reply =?UTF-8?B?THXDrXM=?= Marques <luis luismarques.eu> writes:
On Saturday, 16 July 2016 at 16:19:11 UTC, Andrei Alexandrescu 
wrote:

 Found the problem. Currently allocatorObject allocates the 
 CAllocatorImpl object (interface implementation) straight 
 inside the given allocator, in an ouroboros fashion. 
 Subsequently, deallocateAll deallocates he CAllocatorImpl 
 itself.

 CAllocatorImpl!(A, Yes.indirect) allocatorObject(A)(A* pa)
 {
     assert(pa);
     import std.conv : emplace;
     auto state = pa.allocate(stateSize!(CAllocatorImpl!(A, 
 Yes.indirect)));
     import std.traits : hasMember;
     static if (hasMember!(A, "deallocate"))
     {
         scope(failure) pa.deallocate(state);
     }
     return emplace!(CAllocatorImpl!(A, Yes.indirect))
         (state, pa);
 }


What's the solution? I would say the solution is to use 
theAllocator instead, to allocate the CAllocatorImpl. Or maybe a 
template alias parameter that defaults to theAllocator?
Jul 16 2016
parent Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
On 7/16/16 12:45 PM, Luís Marques wrote:

 On Saturday, 16 July 2016 at 16:19:11 UTC, Andrei Alexandrescu wrote:

 Found the problem. Currently allocatorObject allocates the
 CAllocatorImpl object (interface implementation) straight inside the
 given allocator, in an ouroboros fashion. Subsequently, deallocateAll
 deallocates he CAllocatorImpl itself.

 CAllocatorImpl!(A, Yes.indirect) allocatorObject(A)(A* pa)
 {
     assert(pa);
     import std.conv : emplace;
     auto state = pa.allocate(stateSize!(CAllocatorImpl!(A,
 Yes.indirect)));
     import std.traits : hasMember;
     static if (hasMember!(A, "deallocate"))
     {
         scope(failure) pa.deallocate(state);
     }
     return emplace!(CAllocatorImpl!(A, Yes.indirect))
         (state, pa);
 }


 What's the solution? I would say the solution is to use theAllocator
 instead, to allocate the CAllocatorImpl. Or maybe a template alias
 parameter that defaults to theAllocator?


I don't know yet. Thinking of it. -- Andrei
Jul 17 2016
prev sibling parent Enamex <enamex+d outlook.com> writes:
On Friday, 15 July 2016 at 18:44:26 UTC, Luís Marques wrote:

 I'm not having success trying to use the allocator API.
     void main()
     {
         [...]
         enforce(alloc.make!int !is null);
         enforce(alloc.deallocateAll());

         enforce(alloc.make!int !is null);
         writeln("OK 1");
         [...]
     }


I get a segmentation fault before "OK 1", actually. I'd have 
expected all enforce checks to pass in this snip, but they don't 
after the first `deallocateAll()` so I'm misunderstanding the 
semantics big time.
Jul 16 2016