Is there any way (I checked core.memory already) to collect report about memory usage from garbage collector? So, I can see a list of pointer and length information. Since getting this information would require another memory area in heap, it could be like logging when report is asked.

My long running but idle program starts using 41.7% of memory (that's close to 3GB), and it is not obvious whether the memory is allocated by a single variable, or many variables.

On Saturday, 20 February 2016 at 05:33:00 UTC, tcak wrote:
> Is there any way (I checked core.memory already) to collect report about memory usage from garbage collector? So, I can see a list of pointer and length information. Since getting this information would require another memory area in heap, it could be like logging when report is asked.
>
> My long running but idle program starts using 41.7% of memory (that's close to 3GB), and it is not obvious whether the memory is allocated by a single variable, or many variables.

My mistake, it is close to 512MB.

On Saturday, 20 February 2016 at 05:34:01 UTC, tcak wrote:
> On Saturday, 20 February 2016 at 05:33:00 UTC, tcak wrote:
>> Is there any way (I checked core.memory already) to collect report about memory usage from garbage collector? So, I can see a list of pointer and length information. Since getting this information would require another memory area in heap, it could be like logging when report is asked.
>>
>> My long running but idle program starts using 41.7% of memory (that's close to 3GB), and it is not obvious whether the memory is allocated by a single variable, or many variables.
>
> My mistake, it is close to 512MB.

Doesn't sounds like precisely what you want, but there are summary reports of GC activity available via the "--DRT-gcopt=profile:1" command line option. More info at: http://dlang.org/spec/garbage.html

--Jon

On Saturday, 20 February 2016 at 05:55:26 UTC, Jon D wrote:
> On Saturday, 20 February 2016 at 05:34:01 UTC, tcak wrote:
>> On Saturday, 20 February 2016 at 05:33:00 UTC, tcak wrote:
>>> Is there any way (I checked core.memory already) to collect report about memory usage from garbage collector? So, I can see a list of pointer and length information. Since getting this information would require another memory area in heap, it could be like logging when report is asked.
>>>
>>> My long running but idle program starts using 41.7% of memory (that's close to 3GB), and it is not obvious whether the memory is allocated by a single variable, or many variables.
>>
>> My mistake, it is close to 512MB.
>
> Doesn't sounds like precisely what you want, but there are summary reports of GC activity available via the "--DRT-gcopt=profile:1" command line option. More info at: http://dlang.org/spec/garbage.html
>
> --Jon

I checked it out now. Yes, it is not that much useful unfortunately.

The process is a daemon. stdin, stdout, and stderr are forwarded to /dev/null,
thus, there is nothing like getting a text report at the end of process.

I am still looking for a way to at least hook up to GC, so when it allocates,
or deallocates, I could log it myself.

On 20.02.2016 07:22, tcak wrote:
> On Saturday, 20 February 2016 at 05:55:26 UTC, Jon D wrote:
>> On Saturday, 20 February 2016 at 05:34:01 UTC, tcak wrote:
>>> On Saturday, 20 February 2016 at 05:33:00 UTC, tcak wrote:
>>>> Is there any way (I checked core.memory already) to collect report
>>>> about memory usage from garbage collector? So, I can see a list of
>>>> pointer and length information. Since getting this information would
>>>> require another memory area in heap, it could be like logging when
>>>> report is asked.
>>>>
>>>> My long running but idle program starts using 41.7% of memory
>>>> (that's close to 3GB), and it is not obvious whether the memory is
>>>> allocated by a single variable, or many variables.
>>>
>>> My mistake, it is close to 512MB.
>>
>> Doesn't sounds like precisely what you want, but there are summary
>> reports of GC activity available via the "--DRT-gcopt=profile:1"
>> command line option. More info at: http://dlang.org/spec/garbage.html
>>
>> --Jon
>
> I checked it out now. Yes, it is not that much useful unfortunately.
>
> The process is a daemon. stdin, stdout, and stderr are forwarded to
> /dev/null,
> thus, there is nothing like getting a text report at the end of process.
>
> I am still looking for a way to at least hook up to GC, so when it
> allocates,
> or deallocates, I could log it myself.

You can add path-to-druntime/src/gc/gc.d to your build command line and add option -debug=PRINTF_TO_FILE. This will redirect output to gcx.log.

If you add option -debug=PRINTF, it will print some API calls. You might have to check gc.d whether the ones that interest you are commented out, though.