digitalmars.D.learn - using D without GC
- Oleg B (54/54) Jun 07 2015 Hello. I want to try use D without GC and I'm not sure what I do
- Rikki Cattermole (11/64) Jun 07 2015 Don't worry about collecting at the end. The OS will clean up the app no...
- Oleg B (43/47) Jun 07 2015 auto myalloc(T)( size_t count )
- Alex Parrill (4/13) Jun 07 2015 Note that you can slice non-gc memory. `Impl` is basically what a
- Andrea Fontana (2/49) Jun 08 2015 I guess you should follow andrei's post about new allocators!
- Oleg B (1/2) Jun 08 2015 Can you get link to this post?
- "Marc =?UTF-8?B?U2Now7x0eiI=?= <schuetzm gmx.net> (9/11) Jun 08 2015 These are some of his posts:
- Oleg B (4/16) Jun 08 2015 Thank! Can you say how long wait (on average) to experimental
- "Marc =?UTF-8?B?U2Now7x0eiI=?= <schuetzm gmx.net> (5/23) Jun 09 2015 Don't know in general. This one isn't even in Phobos yet, but
- Oleg B (3/4) Jun 08 2015 Did you mean this article
- thedeemon (4/6) Jun 07 2015 Actually D runtime will also do a collection before exiting. This
- Mike (5/7) Jun 08 2015 You may want to take a look at this Wiki page. It has several
Hello. I want to try use D without GC and I'm not sure what I do
all right.
import core.memory;
version( gcdis ) enum gc_disable = true;
else enum gc_disable = false;
class Foo
{
byte[][] buf;
this()
{
foreach( i; 0 .. 32 )
buf ~= new byte[]( 65536 * 16 );
}
~this()
{
static if( gc_disable )
{
// no warning about deprecated 'delete'
foreach( i; 0 .. 32 )
delete buf[i];
delete buf;
}
}
}
void main()
{
static if( gc_disable ) GC.disable();
foreach( i; 0 .. 200 )
scope foo = new Foo;
static if( gc_disable )
{
GC.enable();
GC.collect();
}
}
dmd -version=gcdis test.d && ./test "--DRT-gcopt=profile:1"
Number of collections: 2
Total GC prep time: 0 milliseconds
Total mark time: 0 milliseconds
Total sweep time: 0 milliseconds
Total page recovery time: 0 milliseconds
Max Pause Time: 0 milliseconds
Grand total GC time: 0 milliseconds
GC summary: 51 MB, 2 GC 0 ms, Pauses 0 ms < 0 ms
dmd test.d && ./test "--DRT-gcopt=profile:1"
Number of collections: 205
Total GC prep time: 1 milliseconds
Total mark time: 1 milliseconds
Total sweep time: 5 milliseconds
Total page recovery time: 0 milliseconds
Max Pause Time: 0 milliseconds
Grand total GC time: 8 milliseconds
GC summary: 69 MB, 205 GC 8 ms, Pauses 3 ms < 0 ms
I use this feature correctly?
Jun 07 2015
On 7/06/2015 10:16 p.m., Oleg B wrote:
Hello. I want to try use D without GC and I'm not sure what I do all right.
import core.memory;
version( gcdis ) enum gc_disable = true;
else enum gc_disable = false;
class Foo
{
byte[][] buf;
this()
{
foreach( i; 0 .. 32 )
buf ~= new byte[]( 65536 * 16 );
}
~this()
{
static if( gc_disable )
{
// no warning about deprecated 'delete'
foreach( i; 0 .. 32 )
delete buf[i];
delete buf;
}
}
}
void main()
{
static if( gc_disable ) GC.disable();
foreach( i; 0 .. 200 )
scope foo = new Foo;
static if( gc_disable )
{
GC.enable();
GC.collect();
}
}
dmd -version=gcdis test.d && ./test "--DRT-gcopt=profile:1"
Number of collections: 2
Total GC prep time: 0 milliseconds
Total mark time: 0 milliseconds
Total sweep time: 0 milliseconds
Total page recovery time: 0 milliseconds
Max Pause Time: 0 milliseconds
Grand total GC time: 0 milliseconds
GC summary: 51 MB, 2 GC 0 ms, Pauses 0 ms < 0 ms
dmd test.d && ./test "--DRT-gcopt=profile:1"
Number of collections: 205
Total GC prep time: 1 milliseconds
Total mark time: 1 milliseconds
Total sweep time: 5 milliseconds
Total page recovery time: 0 milliseconds
Max Pause Time: 0 milliseconds
Grand total GC time: 8 milliseconds
GC summary: 69 MB, 205 GC 8 ms, Pauses 3 ms < 0 ms
I use this feature correctly?
Don't worry about collecting at the end. The OS will clean up the app no
matter what.
You shouldn't be using delete or new for that matter.
You should be using malloc + free. And emplace.
Also you don't need to enable the GC before telling it to collect.
I can't really help with emplace usage.
But for the record the GC isn't going to slow you down here.
No just reserve some memory and preallocate the buffer you want before
using it. It'll be a lot faster and cheaper.
Concatenation is your real enemy here. Aka realloc.
Jun 07 2015
No just reserve some memory and preallocate the buffer you want before using it. It'll be a lot faster and cheaper.I know, it's only for test.You shouldn't be using delete or new for that matter. You should be using malloc + free. And emplace.auto myalloc(T)( size_t count ) { struct Impl{ size_t len; void* ptr; } union Wrap { Impl impl; T[] arr; } auto ret = Wrap( Impl( count, calloc( count, T.sizeof ) ) ).arr; enforce( ret.ptr !is null ); return ret; } class Bar { float[] buf; this() { buf = myalloc!float( 65536 ); } ~this() { free(buf.ptr); } } For simple types arrays all clear. Emplace realization not trivial for me yet. As I understand correctly it concerns placing initial values of struct for example or values before calling ctor in place to array segment without copying? But what I need use for class objects? class Foo { Bar[] buf; this() { buf = myalloc!Bar( 100 ); // I think it's ok foreach( ref b; buf ) b = new Bar; // but calloc can't initialize class correctly } ~this() { static if( gc_disable ) { foreach( ref b; buf ) delete b; free(buf.ptr); } } } Operator new automatically allocate range in GC-manage memory? If it is whether is possible to change this behavior? It's question relates to emplace too?
Jun 07 2015
"Alex Parrill" <initrd.gz gmail.com>
On Sunday, 7 June 2015 at 16:25:29 UTC, Oleg B wrote:
auto myalloc(T)( size_t count )
{
struct Impl{ size_t len; void* ptr; }
union Wrap { Impl impl; T[] arr; }
auto ret = Wrap( Impl( count, calloc( count, T.sizeof ) )
).arr;
enforce( ret.ptr !is null );
return ret;
}
Note that you can slice non-gc memory. `Impl` is basically what a
slice is internally.
auto ret = calloc(count, T.sizeof)[0..(count*T.sizeof)]
Jun 07 2015
On Sunday, 7 June 2015 at 16:25:29 UTC, Oleg B wrote:I guess you should follow andrei's post about new allocators!No just reserve some memory and preallocate the buffer you want before using it. It'll be a lot faster and cheaper.I know, it's only for test.You shouldn't be using delete or new for that matter. You should be using malloc + free. And emplace.auto myalloc(T)( size_t count ) { struct Impl{ size_t len; void* ptr; } union Wrap { Impl impl; T[] arr; } auto ret = Wrap( Impl( count, calloc( count, T.sizeof ) ) ).arr; enforce( ret.ptr !is null ); return ret; } class Bar { float[] buf; this() { buf = myalloc!float( 65536 ); } ~this() { free(buf.ptr); } } For simple types arrays all clear. Emplace realization not trivial for me yet. As I understand correctly it concerns placing initial values of struct for example or values before calling ctor in place to array segment without copying? But what I need use for class objects? class Foo { Bar[] buf; this() { buf = myalloc!Bar( 100 ); // I think it's ok foreach( ref b; buf ) b = new Bar; // but calloc can't initialize class correctly } ~this() { static if( gc_disable ) { foreach( ref b; buf ) delete b; free(buf.ptr); } } } Operator new automatically allocate range in GC-manage memory? If it is whether is possible to change this behavior? It's question relates to emplace too?
Jun 08 2015
I guess you should follow andrei's post about new allocators!Can you get link to this post?
Jun 08 2015
On Monday, 8 June 2015 at 12:24:56 UTC, Oleg B wrote:These are some of his posts: http://forum.dlang.org/thread/mku0n4$s35$1 digitalmars.com http://forum.dlang.org/thread/mkl1eh$1mdl$2 digitalmars.com http://forum.dlang.org/thread/mjig8h$2rgi$1 digitalmars.com http://forum.dlang.org/thread/mjdcep$11ri$1 digitalmars.com http://forum.dlang.org/thread/mj3p2j$2qva$1 digitalmars.com http://forum.dlang.org/thread/mir0lg$2l74$1 digitalmars.com http://forum.dlang.org/thread/min9k8$9r9$1 digitalmars.comI guess you should follow andrei's post about new allocators!Can you get link to this post?
Jun 08 2015
On Monday, 8 June 2015 at 13:37:40 UTC, Marc Schütz wrote:On Monday, 8 June 2015 at 12:24:56 UTC, Oleg B wrote:Thank! Can you say how long wait (on average) to experimental modules will cease be an experimental and will be part of phobos? At next release or it unknown?These are some of his posts: http://forum.dlang.org/thread/mku0n4$s35$1 digitalmars.com http://forum.dlang.org/thread/mkl1eh$1mdl$2 digitalmars.com http://forum.dlang.org/thread/mjig8h$2rgi$1 digitalmars.com http://forum.dlang.org/thread/mjdcep$11ri$1 digitalmars.com http://forum.dlang.org/thread/mj3p2j$2qva$1 digitalmars.com http://forum.dlang.org/thread/mir0lg$2l74$1 digitalmars.com http://forum.dlang.org/thread/min9k8$9r9$1 digitalmars.comI guess you should follow andrei's post about new allocators!Can you get link to this post?
Jun 08 2015
On Monday, 8 June 2015 at 20:11:31 UTC, Oleg B wrote:On Monday, 8 June 2015 at 13:37:40 UTC, Marc Schütz wrote:Don't know in general. This one isn't even in Phobos yet, but OTOH it is a feature that's very much in demand, so the process might be sped up. Maybe it could even go directly to std.allocator instead of std.experimental.allocator...On Monday, 8 June 2015 at 12:24:56 UTC, Oleg B wrote:Thank! Can you say how long wait (on average) to experimental modules will cease be an experimental and will be part of phobos? At next release or it unknown?These are some of his posts: http://forum.dlang.org/thread/mku0n4$s35$1 digitalmars.com http://forum.dlang.org/thread/mkl1eh$1mdl$2 digitalmars.com http://forum.dlang.org/thread/mjig8h$2rgi$1 digitalmars.com http://forum.dlang.org/thread/mjdcep$11ri$1 digitalmars.com http://forum.dlang.org/thread/mj3p2j$2qva$1 digitalmars.com http://forum.dlang.org/thread/mir0lg$2l74$1 digitalmars.com http://forum.dlang.org/thread/min9k8$9r9$1 digitalmars.comI guess you should follow andrei's post about new allocators!Can you get link to this post?
Jun 09 2015
I guess you should follow andrei's post about new allocators!Did you mean this article http://wiki.dlang.org/Memory_Management#Explicit_Class_Instance_Allocation ?
Jun 08 2015
On Sunday, 7 June 2015 at 10:23:22 UTC, Rikki Cattermole wrote:Don't worry about collecting at the end. The OS will clean up the app no matter what.Actually D runtime will also do a collection before exiting. This is why it shows "Number of collections: 2" above. One triggered manually, one by runtime.
Jun 07 2015
On Sunday, 7 June 2015 at 10:16:36 UTC, Oleg B wrote:Hello. I want to try use D without GC and I'm not sure what I do all right.You may want to take a look at this Wiki page. It has several patterns managing memory without the GC: http://wiki.dlang.org/Memory_Management Mike
Jun 08 2015