• Kagamin (1/1) Feb 20 2016 It doesn't even compile: http://dpaste.dzfl.pl/ec0f5183e42e
• Chris Wright (12/13) Feb 20 2016 Check the error. Add a `cast(size_t)` in there. Try again.
• Steven Schveighoffer (4/9) Feb 20 2016 Let's not forget that you need 18 exabytes of ram too. And you
• Chris Wright (4/13) Feb 20 2016 Point. The GC uses calloc, which does happen to complain when I ask for
• rsw0x (7/8) Feb 20 2016 This looks like it's a limit purely on the interface for

Kagamin <spam here.lot> writes:

It doesn't even compile: http://dpaste.dzfl.pl/ec0f5183e42e

Chris Wright <dhasenan gmail.com> writes:

On Sat, 20 Feb 2016 17:04:11 +0000, Kagamin wrote:

 It doesn't even compile: http://dpaste.dzfl.pl/ec0f5183e42e

Check the error. Add a `cast(size_t)` in there. Try again.

That's still doomed to failure. You're not leaving space for the stack 
(which has preallocated address space) or application binary (which is 
memory mapped from the file and takes up address space). You're using the 
garbage collector, which has to allocate its own internal data structures 
somewhere.

If you subtract those from your allocation request, you still won't see 
much success. There's no guarantee where in memory those items will be 
allocated, and if your system has ASLR turned on by default, it's even 
less predictable.

If you tried a similar thing in C, you'd see the same problems.

Steven Schveighoffer <schveiguy yahoo.com> writes:

On Saturday, 20 February 2016 at 17:21:42 UTC, Chris Wright wrote:
 That's still doomed to failure. You're not leaving space for 
 the stack (which has preallocated address space) or application 
 binary (which is memory mapped from the file and takes up 
 address space). You're using the garbage collector, which has 
 to allocate its own internal data structures somewhere.

Let's not forget that you need 18 exabytes of ram too. And you 
want it initialized? That's going to take a while ;)

-Steve

Chris Wright <dhasenan gmail.com> writes:

On Sat, 20 Feb 2016 18:07:59 +0000, Steven Schveighoffer wrote:

 On Saturday, 20 February 2016 at 17:21:42 UTC, Chris Wright wrote:
 That's still doomed to failure. You're not leaving space for the stack
 (which has preallocated address space) or application binary (which is
 memory mapped from the file and takes up address space). You're using
 the garbage collector, which has to allocate its own internal data
 structures somewhere.

 
 Let's not forget that you need 18 exabytes of ram too.

Point. The GC uses calloc, which does happen to complain when I ask for 
vast amounts of memory. There are other ways of requesting address space, 
though, such as mmap(2).

rsw0x <anonymous anonymous.com> writes:

On Saturday, 20 February 2016 at 17:04:11 UTC, Kagamin wrote:
 It doesn't even compile: http://dpaste.dzfl.pl/ec0f5183e42e

This looks like it's a limit purely on the interface for 
allocating arrays from the GC.

i.e,

ubyte* ptr;
ubyte arr = ptr[0 .. size_t.max];

compiles just fine