Re: [Caml-list] Potential OCaml-ZMQ memory management problems

[Kenneth Adam Miller <kennethadammiller@gmail.com>]

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Ok I'll give that a shot when I get a chance to edit it. Thanks,
gc.major... I'm new to ocaml and I'm still reading through RWO, on chapter
9 learning about how modules compose nicely :)

On Thu, Dec 4, 2014 at 4:59 AM, Anders Fugmann <anders@fugmann.net> wrote:

> The garbage collector settings seems quite sane to me. You could try to
> force a major collection every call to iltrans.
>
> Gc.major ()
>
> It could be that the segfault is really an out of memory situation. Maybe
> you have a leak in your code somewhere (Not releasing references to large
> objects).
>
> /Anders
>
>
> On 12/04/2014 09:02 AM, Kenneth Adam Miller wrote:
>
>> I'm using zmq and ocaml-zmq as installed by opam; I'm not at my work
>> computer or I would provide those details.
>>
>> Yes, I will try to work on creating a reproducible script
>>
>> Could it possibly be a call to Tunegc.set_gc () from
>> https://github.com/argp/bap/blob/master/ocaml/tunegc.ml ?
>>
>> I notice that this error didn't appear in single calls to my utility;
>> basically, I'm using iltrans from bap and I'm using it in a long living
>> process, unlike the current implementation which expects a few
>> transformations and then process death. I did notice that when I run it,
>> if I'm watching system monitor that it begins consuming vast amounts of
>> memory (quickly grows from a few megabytes to 800+) before it hits
>> segfault. Would there be any way to restore the aggressiveness of the GC
>> between calls to iltrans?
>>
>> On Thu, Dec 4, 2014 at 2:55 AM, Anders Fugmann <anders@fugmann.net
>> <mailto:anders@fugmann.net>> wrote:
>>
>>     Hi Kenneth,
>>
>>     The Ocaml-zmq code copies data from received messages into memory
>> under
>>     the control of the ocaml garbage collector, and immediatly frees the
>>     ZMQ buffers.
>>
>>     You do not need to explicitly free the data received from call to
>> recv.
>>
>>     Can you produce a small sample code that exposes the problem? We are
>>     using the ocaml-zmq binding extensively, and have not seen any
>> problems.
>>
>>     If I were to take a wild guess, it either a mismatch between library
>>     versions or the garbage-collector collecting the socket or zmq
>> context.
>>
>>     What version of the ocaml-zmq bindings and libzmq (c impl) are you
>>     using?
>>
>>     /Anders
>>
>>
>>
>>     On 12/04/2014 07:09 AM, Kenneth Adam Miller wrote:
>>
>>         I'm using ocaml-zmq (https://github.com/issuu/__ocaml-zmq
>>         <https://github.com/issuu/ocaml-zmq>) and I think I'm
>>         encountering a memory management issue. I could be wrong
>>         however, but
>>         basically the issue (I think) is I have a rather large set of
>>         messages
>>         to send via zmq, and I'm getting a segfault.
>>
>>         Does anybody know if I need to free the strings received from
>>         zmq recv
>>         functions in ocaml? If so how do I do that from ocaml?
>>
>>         There's no code because this is just a general novice ocaml
>>         questions.
>>
>>
>>
>>
>

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