Hello. On 2014-06-19 at 18:20, nore...@launchpad.net wrote:
> Fixed a possible very critical memory leak introduced in revno > 388. The problem was occurring in a thread calling the function > Linux.process.stat' repetitively in a loop. Strangely, the source of > the problem seems to be the standard function `Scanf.fscanf'. In a way > that I don't understand, `fscanf' seems able to get the GC confused: > unused `Linux.process.stat' structures are indeed not collected (even > forcing a collection with Gc.full_major). The workaround adopted > consists in replacing `Scanf.fscanf ch' by a `Scanf.sscanf line' where > line' is read from `ch' by `Pervasives.input_line'. Now `stat' > structures seem to be correctly collected. Interesting. As a guess without looking at OCaml runtime source code, I'd suspect this to be a buffering issue in fscanf, which gobbles up a large memory buffer as an OCaml string without releasing it, with the intent of reusing it for the next read operation. By contrast sscanf takes a string as a parameter which is explicitly supplied by the user, and when that gets unreachable it immediately becomes a candidate for collection. Are you reading very large strings? Very good catch anyway :-). This must not have been easy to isolate. -- Luca Saiu http://ageinghacker.net * GNU epsilon: http://www.gnu.org/software/epsilon * Vaucanson: http://vaucanson-project.org * Marionnet: http://marionnet.org _______________________________________________ Mailing list: https://launchpad.net/~marionnet-dev Post to : marionnet-dev@lists.launchpad.net Unsubscribe : https://launchpad.net/~marionnet-dev More help : https://help.launchpad.net/ListHelp
