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digitalmars.D.learn - Hooking into GC

reply MMJones <MMJones mail.com> writes:
I read somewhere that one can modify the D files from phobos and 
runtime to supply a stub for the GC. I would like to add some 
logging features to the GC.

Does this not require one to recompile phobos? I figured the 
source code was just for debugging?

I'm curious if I can really get away with modifying the source 
code in dmd2's dir and it will actually work. I guess I could try 
but I don't wanna go mess with it if it's not going to do 
anything.
Jun 28 2016
next sibling parent reply thedeemon <dlang thedeemon.com> writes:
On Wednesday, 29 June 2016 at 02:18:27 UTC, MMJones wrote:

 I read somewhere that one can modify the D files from phobos 
 and runtime to supply a stub for the GC. I would like to add 
 some logging features to the GC.



You don't need to recompile anything, a stub can be installed 
from your program. See an example (which can do logging) here:
https://bitbucket.org/infognition/dstuff/src/97cef6d4a0438f9a9f4ff0d18f819262b8a74888/trackallocs.d?fileviewer=file-view-default
Jun 28 2016
parent reply MMJones <MMJones mail.com> writes:
On Wednesday, 29 June 2016 at 03:10:10 UTC, thedeemon wrote:

 On Wednesday, 29 June 2016 at 02:18:27 UTC, MMJones wrote:

 I read somewhere that one can modify the D files from phobos 
 and runtime to supply a stub for the GC. I would like to add 
 some logging features to the GC.



 You don't need to recompile anything, a stub can be installed 
 from your program. See an example (which can do logging) here:
 https://bitbucket.org/infognition/dstuff/src/97cef6d4a0438f9a9f4ff0d18f819262b8a74888/trackallocs.d?fileviewer=file-view-default


Yeah, I saw that. I'm looking the general answer though. Not just 
for GC. Does D basically combine the d files in to phobos when 
they are modified?

What if I want to log all file operations? It would be easier to 
stick a log function in std.file but I have a feeling it won't be 
recompiled and used.
Jun 28 2016
parent =?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:
On 06/28/2016 08:39 PM, MMJones wrote:


 Yeah, I saw that. I'm looking the general answer though. Not just for
 GC. Does D basically combine the d files in to phobos when they are
 modified?


No. Somebody must explicitly build the library.

However, any code that's templated cannot be pre-built because it must 
work with user-defined types, which the compiler cannot be aware of 
ahead of time.


 What if I want to log all file operations? It would be easier to stick a
 log function in std.file but I have a feeling it won't be recompiled and
 used.


It won't work with the non-templated parts of the library but go ahead 
and modify almost anything in std.algorithm and you will see the effect 
as soon as you compile your program. :)

Ali
Jun 28 2016
prev sibling parent reply Martin Nowak <code dawg.eu> writes:
On Wednesday, 29 June 2016 at 02:18:27 UTC, MMJones wrote:

 I read somewhere that one can modify the D files from phobos 
 and runtime to supply a stub for the GC. I would like to add 
 some logging features to the GC.

 Does this not require one to recompile phobos? I figured the 
 source code was just for debugging?

 I'm curious if I can really get away with modifying the source 
 code in dmd2's dir and it will actually work. I guess I could 
 try but I don't wanna go mess with it if it's not going to do 
 anything.


Going to be released with 2.072.0
https://github.com/dlang/druntime/pull/1581
Jun 29 2016
parent reply MMJones <MMJones mail.com> writes:
On Wednesday, 29 June 2016 at 10:07:19 UTC, Martin Nowak wrote:

 On Wednesday, 29 June 2016 at 02:18:27 UTC, MMJones wrote:

 I read somewhere that one can modify the D files from phobos 
 and runtime to supply a stub for the GC. I would like to add 
 some logging features to the GC.

 Does this not require one to recompile phobos? I figured the 
 source code was just for debugging?

 I'm curious if I can really get away with modifying the source 
 code in dmd2's dir and it will actually work. I guess I could 
 try but I don't wanna go mess with it if it's not going to do 
 anything.


 Going to be released with 2.072.0
 https://github.com/dlang/druntime/pull/1581


How will this affect the trackallocs module? Will it break it, 
replace it? Essentially a merge of it? Should I hold off until 
2.072 or go ahead and use the stub. I only need monitoring, not 
replacement of the GC.
Jun 29 2016
parent reply Martin Nowak <code dawg.eu> writes:
On Wednesday, 29 June 2016 at 14:41:48 UTC, MMJones wrote:

 On Wednesday, 29 June 2016 at 10:07:19 UTC, Martin Nowak wrote:
 How will this affect the trackallocs module? Will it break it, 
 replace it? Essentially a merge of it? Should I hold off until 
 2.072 or go ahead and use the stub. I only need monitoring, not 
 replacement of the GC.


It'll break it b/c we've replaced the proxy with a real interface.
I think your use-case is fully covered by the GC profiler 
(http://forum.dlang.org/thread/mi62uu$14lu$1 digitalmars.com) and 
GC stats (https://dlang.org/spec/garbage.html#gc_config, 
https://github.com/dlang/druntime/pull/1591).
Jun 29 2016
parent reply MMJones <MMJones mail.com> writes:
On Thursday, 30 June 2016 at 01:26:47 UTC, Martin Nowak wrote:

 On Wednesday, 29 June 2016 at 14:41:48 UTC, MMJones wrote:

 On Wednesday, 29 June 2016 at 10:07:19 UTC, Martin Nowak wrote:
 How will this affect the trackallocs module? Will it break it, 
 replace it? Essentially a merge of it? Should I hold off until 
 2.072 or go ahead and use the stub. I only need monitoring, 
 not replacement of the GC.


 It'll break it b/c we've replaced the proxy with a real 
 interface.
 I think your use-case is fully covered by the GC profiler 
 (http://forum.dlang.org/thread/mi62uu$14lu$1 digitalmars.com) 
 and GC stats (https://dlang.org/spec/garbage.html#gc_config, 
 https://github.com/dlang/druntime/pull/1591).


I need to get more info than just the memory usage. Like what is 
using the memory.
Jun 29 2016
parent Martin Nowak <code dawg.eu> writes:
On Thursday, 30 June 2016 at 03:03:16 UTC, MMJones wrote:

 I need to get more info than just the memory usage. Like what 
 is using the memory.


That's what -profile-gc is for, it tracks allocations.
Give it a try, IIIRC it's missing explicit GC.malloc calls atm., 
but those should be rare anyhow and could be added.
http://dlang.org/changelog/2.068.0.html#profile-gc
Jun 29 2016