Re: [libmicrohttpd] MHD_get_fdset throws "Illegal instruction" error

[Evgeny Grin]

Thanks for report!
Yes, MHD_get_fdset2() do not handle situation with thread pool as it
designed to be called from user code only for daemons running external
select.
Fixed in master by return always MHD_NO for daemons with internal
select()/poll()/epoll.
Also now MHD_run() and MHD_run_from_select() always return errors too
for such daemons.

To make it clear: if you start MHD with any option of
MHD_USE_SELECT_INTERNALLY, MHD_USE_POLL_INTERNALLY,
MHD_USE_EPOLL_INTERNALLY or MHD_USE_THREAD_PER_CONNECTION then MHD will
start internal thread(s) and will automatically process incoming
connection with callbacks to user code. You can't use MHD_get_fdset2(),
MHD_get_fdset(), MHD_run(), MHD_run_from_select() as MHD is already
running in other thread.
Note that MHD_OPTION_THREAD_POOL_SIZE require usage of internal threads.

-- 
Best Wishes,
Evgeny Grin

On 15.03.2017 12:57, Vitaliy T wrote:
> Seems to be I have found the root of the problem.
> 
> When I call MHD_get_fdset2() the values are next:
> 
> 1. daemon->epoll_fd == -1 (as I said before).
> 2. daemon->worker_pool[0].epoll_fd == 7 (as it was set initially).
> 
> Someone should fix this, because at the moment I don't know how to do
> this correctly.
>