Re: block_input for some APIs

[YAMAMOTO Mitsuharu]

>>>>> On Mon, 12 Dec 2016 16:48:53 -0500, Stefan Monnier <address@hidden> said:

>>> Does anyone remember why we block input around calls to functions like
>>> getpwnam or tzset or fwrite?
>> I think this dates back to when C-g and/or other handlers called
>> longjmp.

> I'm not completely sure, but my own impression is that this dates back
> to before SYNC_INPUT, i.e. with input became available, we'd get an IO
> signal and in the handler we'd run a whole bunch of code, since
> reentrance was a big issue.  Nowadays we delay this async processing to
> the next QUIT so there's no re-entrance issue any more.

I added some of them around early 2007, when SYNC_INPUT was not used
by default.  These functions call malloc etc. internally (at least on
Darwin), so it was not safe to call read_socket_hook, which also calls
malloc etc., from SIGIO/SIGALRM handler while processing getpwnam etc.

                                     YAMAMOTO Mitsuharu
                                address@hidden