On Tue 22 Feb 2011 12:36, l...@gnu.org (Ludovic Courtès) writes:
>>>> +
>>>> + if (p->input_cd != (iconv_t) -1)
>>>> + {
>>>> + iconv_close (p->input_cd);
>>>> + p->input_cd = (iconv_t) -1;
>>>> + }
>>>> +
>>>> + if (p->output_cd != (iconv_t) -1)
>>>> + {
>>>> + iconv_close (p->output_cd);
>>>> + p->output_cd = (iconv_t) -1;
>>>> + }
>>>> +
>>>
>>> I don’t think this is needed: each port has a finalizer,
>>> ‘finalize_port’, which normally takes care of this, eventually.
>>
>> It is needed, but only in the case that you `close-port' explicitly.
>> The block in finalize_port only takes care of gc'd open ports.
>
> Right. Closed ports are eventually GC’d, so in that sense it is not
> strictly needed, but OK.
>
> Valgrind was wrong! ;-)
You are setting yourself up for a fall here ;)
When you close a port via "close-port", you remove the port's
SCM_PTAB_ENTRY (port). The SCM_PTAB_ENTRY points to the iconv_t, so the
finalizer would not have a chance to free it, because it can't get to
it. You need to free the iconv_t at the time you remove the link from
the port to the SCM_PTAB_ENTRY -- i.e. at close-port time. Otherwise
you leak the iconv_t.
Trust me: about 500K requests into meta/guile examples/web/hello.scm,
the memory usage was up at about a gigabyte or so :)
Andy
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