Derek Zhou writes:

> Robert Pluim writes:
>
>> Thatʼs always possible. You'd have to stick some instrumentation in
>> things like connect_network_socket and wait_reading_process_output to
>> narrow it down.
>>
> I think what happened is gnutls's internal buffering exhausts the
> available data from the socket, so select blocks. There is an comment in
> the code said gnutls leave one byte in the socket for select, but I
> don't think it is doing this anymore. The following patch move the check
> before the select and skip the select if there is data to be read in
> gnutls. It fixed the occational stall in https.

Sorry, the previous patch was wrong. Cannot reuse the fd_set intended
for select. Corrected: