• Hoenir <mrmocool gmx.de> Jul 24 2007
• "Jarrett Billingsley" <kb3ctd2 yahoo.com> Jul 24 2007
• Hoenir <mrmocool gmx.de> Jul 24 2007
• janderson <askme me.com> Jul 24 2007
• Dave <Dave_member pathlink.com> Jul 24 2007

Hoenir <mrmocool gmx.de> writes:

I'm wondering when and how to "disable" the GC and do the memory 
mangement yourself?

"Jarrett Billingsley" <kb3ctd2 yahoo.com> writes:

"Hoenir" <mrmocool gmx.de> wrote in message 
news:f84sio$22an$1 digitalmars.com...
 I'm wondering when and how to "disable" the GC and do the memory mangement 
 yourself?


import std.gc;
std.gc.disable(); 

Hoenir <mrmocool gmx.de> writes:

Jarrett Billingsley schrieb:
 I'm wondering when and how to "disable" the GC and do the memory mangement 
 yourself?


 import std.gc;
 std.gc.disable(); 


I don't want to disable it completely. I'm just wondering when it is 
advantageous to do MM yourself and how to do it.
How to prevent a variable from being deleted by the GC and such stuff.
But thanks for your answer. :)

janderson <askme me.com> writes:

Hoenir wrote:
 Jarrett Billingsley schrieb:
 I'm wondering when and how to "disable" the GC and do the memory 
 mangement yourself?


 import std.gc;
 std.gc.disable(); 


 I don't want to disable it completely. I'm just wondering when it is 
 advantageous to do MM yourself and how to do it.


I haven't done this in D so I can't comment.

 How to prevent a variable from being deleted by the GC and such stuff.
 But thanks for your answer. :)


import std.gc;
//...
std.gc.disable();

//Do what ever non gc class allocation you want (you'll have to clean 
these up specifically yourself).

std.gc.enable();

You may want to do this for deterministic destruction, for optimization 
reason, or if you allocate from some sort of special memory.

-Joel

Dave <Dave_member pathlink.com> writes:

Hoenir wrote:
 Jarrett Billingsley schrieb:
 I'm wondering when and how to "disable" the GC and do the memory 
 mangement yourself?


 import std.gc;
 std.gc.disable(); 


 I don't want to disable it completely. I'm just wondering when it is 
 advantageous to do MM yourself and how to do it.
 How to prevent a variable from being deleted by the GC and such stuff.
 But thanks for your answer. :)


Hmmm, there are a few cases when the GC will not release memory because of
pointer 
misidentification, and there are a couple of cases where the GC won't 'mark' a
pointer.

Also, allocating in a tight loop is mostly faster with MM as it stands right
now.

For example:

align(1)
struct PackedStruct
{
     short s;
     char *c;
}
//...
PackedStruct* s;
s = new PackedStruct;
s.c = new char[100]; // GC won't mark s.c unless you manually add it as a root

See more here: http://digitalmars.com/d/garbage.html

For non-OOP, basically you do manual MM the same as C w/ a slightly different
syntax.

There's more here: http://digitalmars.com/d/memory.html

Short example to get you started:

;---

import std.c.stdlib;

void main()
{
     const ELEMS = 100;
     int* array = cast(int*)malloc(ELEMS * int.sizeof);
//  ...
     free(array);
     array = null;
}

HTH.