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select
for data connectionsCalls Unix select
for data connections in a parallel cluster.
This function is for advanced usage (and therefore has minimal documentation), typically the programming of schedulers. It can be called at the client or at a server.
connections: valid connections object (see pconnect
and
pserver
, possibly indexed).
timeout: seconds, negative for infinite.
nfds: Passed to Unix select
as first argument, see
documentation of Uix select
. Default: FD_SETSIZE
(platform specific).
An error is returned if nfds or a watched filedescriptor plus one exceeds FD_SETSIZE.
Returns an index vector to connections indicating connections
with pending input, readable with precv
.
If called at the client, the command connections are included into the
UNIX select
call and checked for error flags, and
select_sockets
returns an error if a flag for a remote error is
received.
See also: pconnect, pserver, reval, psend, precv, sclose, parallel_generate_srp_data.