class PG::Connection

def async_connect_or_reset: (Symbol poll_meth) -> Encoding

def async_connect_or_reset(poll_meth)
 the progress of the connection, waiting for the socket to become readable/writable before polling it
eo = conninfo_hash[:connect_timeout].to_i) && timeo > 0
st timeout is 2 seconds - like in libpq
= [timeo, 2].max
ount = conninfo_hash[:host].to_s.count(",") + 1
ime = timeo * host_count + Process.clock_gettime(Process::CLOCK_MONOTONIC)
atus = PG::PGRES_POLLING_WRITING
oll_status == PG::PGRES_POLLING_OK ||
status == PG::PGRES_POLLING_FAILED
single timeout to parameter "connect_timeout" but
t exceed total connection time of number-of-hosts * connect_timeout.
t = [timeo, stop_time - Process.clock_gettime(Process::CLOCK_MONOTONIC)].min if stop_time
= if !timeout || timeout >= 0
the socket needs to read, wait 'til it becomes readable to poll again
poll_status
PG::PGRES_POLLING_READING
efined?(IO::READABLE) # ruby-3.0+
ket_io.wait(IO::READABLE | IO::PRIORITY, timeout)

select([socket_io], nil, [socket_io], timeout)
and the same for when the socket needs to write
PG::PGRES_POLLING_WRITING
efined?(IO::WRITABLE) # ruby-3.0+
se wait instead of wait_readable, since connection errors are delivered as
xceptional/priority events on Windows.
ket_io.wait(IO::WRITABLE | IO::PRIORITY, timeout)

o#wait on ruby-2.x doesn't wait for priority, so fallback to IO.select
select(nil, [socket_io], [socket_io], timeout)
ection to server at "localhost" (127.0.0.1), port 5433 failed: timeout expired (PG::ConnectionBad)
ection to server on socket "/var/run/postgresql/.s.PGSQL.5433" failed: No such file or directory
 event
lf.class.send(:host_is_named_pipe?, host)
host = "on socket \"#{host}\""
 respond_to?(:hostaddr)
host = "at \"#{host}\" (#{hostaddr}), port #{port}"
host = "at \"#{host}\", port #{port}"
 PG::ConnectionBad.new("connection to server #{connhost} failed: timeout expired", connection: self)
k to see if it's finished or failed yet
tatus = send( poll_meth )
status == PG::CONNECTION_OK
error_message

PG::ConnectionBad.new(msg, connection: self)
onnection to nonblocking to handle all blocking states in ruby.
way a fiber scheduler is able to handle IO requests.
tnonblocking(true)
ush_data = true
ault_encoding