our $last_port_assigned;

our $mm_listen_address = '127.0.0.1';

{

# Tracking of last port value assigned to accelerate free port lookup.

$last_port_assigned = int(rand() * 1000) + 25999;

}

sub mm_get_free_port

{

my $found = 0;

my $port = $last_port_assigned;

while ($found == 0)

{

# advance $port, wrapping correctly around range end

$port = 26000 if ++$port >= 27000;

print "# Checking port $port\n";

# Check first that candidate port number is not included in

# the list of already-registered nodes.

$found = 1;

foreach my $node (@PostgresNode::all_nodes)

{

$found = 0 if ($node->port == $port);

}

# Check to see if anything else is listening on this TCP port.

# Seek a port available for all possible listen_addresses values,

# so callers can harness this port for the widest range of purposes.

# The 0.0.0.0 test achieves that for post-2006 Cygwin, which

# automatically sets SO_EXCLUSIVEADDRUSE. The same holds for MSYS (a

# Cygwin fork). Testing 0.0.0.0 is insufficient for Windows native

# Perl (https://stackoverflow.com/a/14388707), so we also test

# individual addresses.

#

# On non-Linux, non-Windows kernels, binding to 127.0.0/24 addresses

# other than 127.0.0.1 might fail with EADDRNOTAVAIL. Binding to

# 0.0.0.0 is unnecessary on non-Windows systems.

if ($found == 1)

{

foreach my $addr (qw(127.0.0.1),

$PostgresNode::use_tcp ? qw(127.0.0.2 127.0.0.3 0.0.0.0) : ())

{

if (!PostgresNode::can_bind($addr, $port))

{

$found = 0;

last;

}

}

}

}

print "# Found port $port\n";

# Update port for next time

$last_port_assigned = $port;

return $port;

}

# ask PostgresNode to use tcp and listen on mm_listen_address

$PostgresNode::use_tcp = 1;

$PostgresNode::test_pghost = $mm_listen_address;

my @nodes = map { get_new_node("node$_", ('port' => mm_get_free_port())) } (1..$n_nodes);

$self->{referee} = get_new_node("referee", ( 'port' => mm_get_free_port() ));