Re: [GSoC 2017] Number fo sockets

[Kalle Olavi Niemitalo]

Kalle Olavi Niemitalo <kon@iki.fi> writes:

> I wonder how hard it would be to implement those select ops in
> the translator without hogging a thread for each.

To clarify: if one thread in a program calls select on an fd_set
that lists ten sockets, then glibc sends ten io_select requests
before it waits for any response, and this costs ten threads in
the lwip translator if none of the sockets is ready.  Adding
lwip_poll does not help with that.  The struct lwip_select_cb
would have to be allocated from the heap and there would have to
be a way to unlink and free it if glibc destroys the reply port.