my $loop = IO::Async::Loop->new;
my $ep = Net::Async::EmptyPort->new(
loop => $loop,
);
# could take a while to start...
my $chosen_port = start_server_in_background();
$ep->wait_port({ port => $chosen_port })->get;
DESCRIPTION
This module is an asynchronous port of Net::EmptyPort. The interface is
different and thus simplified from the original. A couple of the
original methods are not implemented; specifically can_bind and
check_port. They are not hard to implement but I don't have a good idea
of why someone would use them.
METHODS
empty_port
my $listen_future = $ep->empty_port({
host => '192.168.1.1',
port => 8000,
proto => 'tcp',
});
This method has no required arguments but accepts the following named
parameters:
* host
Defaults to 127.0.0.1
* port
Defaults to 0; which means the kernel will immediately provide an
open port. Alternately, if you provide a port Net::Async::EmptyPort
will try that port up through to port 65000.
* proto
Defaults to tcp; the other option is udp.
The return value is an IO::Async::Listener. The easiest way (though
this will introduce a race condition) to make it work like the original
is as follows:
Then the Future will simply contain the port, though a better option is
to pass the actual listener or socket to whatever will use it if
possible.
wait_port
my $socket_future = $ep->wait_port({
port => 8080,
proto => 'tcp',
host => '192.168.1.1',
max_wait => 60,
});
This method takes the following named parameters:
* host
Defaults to 127.0.0.1
* port
Required.
* proto
Defaults to tcp; the other option is udp.
* max_wait
Defaults to 10 seconds. Set to -1 to wait indefinitely.
The return value is a Future containing an IP::Socket::IP. You can use
that for connecting, but unlike "empty_port" there is no race condition
here so it makes perfect sense to just use wait_port as a "blocker."
wait_port uses a basic exponential backoff to avoid quickly polling.
Eventually the backoff method will be configurable.
