Spread(3pm)
NAME
Spread - Perl extension for the Spread group communication system
SYNOPSIS
use Spread;
# Connect
my($mailbox, $private_group) = Spread::connect(
spread_name => '4444@host.domain.com',
private_name => 'mrcool',
);
# Join and leave groups
my(@group_to_join) = ( 'GroupA', 'GroupB', 'GroupC' );
my(@joined_groups) = grep( Spread::join($mbox, $_), @group_to_join );
print "Spread::join -- $sperrorno"
unless (Spread::leave($mbox, 'GroupC'));
# Multicast to group(s)
Spread::multicast($mbox, AGREED_MESS, 'GroupB', 0, "Hey you!");
Spread::multicast($mbox, SAFE_MESS, @joined_groups, 0, "Hey yall!");
# Poll mailbox
my($messsize) = Spread::poll($mbox);
if(defined($messsize)) { print "Next message: $messsize bytes\n"; }
else { print "Spread::poll $sperrno\n"; }
# Receive messages (see spread's man pages for more description)
my($service_type, $sender, $groups, $mess_type, $endian, $message) =
Spread::receive($mbox);
my($service_type, $sender, $groups, $mess_type, $endian, $message) =
Spread::receive($mbox, 1.789); # 1.789 second timeout on receive
# Disconnect
if(Spread::disconnect($mbox)) { print "Successful disconnect\n"; }
else { print "Spread::disconnect -- $sperrorno\n"; }
DESCRIPTION
Understanding through practice ;)
See man pages for SP_connect, SP_join, SP_multicast, SP_receive,
SP_poll, SP_error, SP_leave, SP_disconnect.
$sperror holds either the integer spread error or a descriptive string
depending on the context in which $sperror is used.
Exported constants
The predefined groups of exports in the use statements are as follows:
use Spread qw(:SP);
Exports the Spread::connect, Spread::join, Spread::multicast,
Spread::receive, Spread::poll, Spread::error, Spread::leave, and
Spread::disconnect as SP_connect, SP_join, SP_multicast, SP_receive,
SP_poll, SP_error, SP_leave, and SP_disconnect, respectively.
use Spread qw(:ERROR);
Exports all of the error conditions. Please refer to the SP_* C man
pages as the "RETURN VALUES" there have both identical spellings and
meanings.
use Spread qw(:MESS);
Exports all of the message types (this is returned as service type by
the Spread::receive function and is the request service type of the
Spread::multicast function). The actual meaning of these orderings and
assurances are not simple to explain without a basic understanding of
group communication systems. For more information on this topic,
please visit the Spread web site at http://www.spread.org/
- All constants in alphabetical order:
- ACCEPT_SESSION
AGREED_MESS
BUFFER_TOO_SHORT
CAUSAL_MESS
CAUSED_BY_DISCONNECT
CAUSED_BY_JOIN
CAUSED_BY_LEAVE
CAUSED_BY_NETWORK
CONNECTION_CLOSED
COULD_NOT_CONNECT
FIFO_MESS
HIGH_PRIORITY
ILLEGAL_GROUP
ILLEGAL_MESSAGE
ILLEGAL_SERVICE
ILLEGAL_SESSION
ILLEGAL_SPREAD
LOW_PRIORITY
MAX_SCATTER_ELEMENTS
MEDIUM_PRIORITY
MEMBERSHIP_MESS
REGULAR_MESS
REG_MEMB_MESS
REJECT_ILLEGAL_NAME
REJECT_NOT_UNIQUE
REJECT_NO_NAME
REJECT_QUOTA
REJECT_VERSION
RELIABLE_MESS
SAFE_MESS
SELF_DISCARD
TRANSITION_MESS
UNRELIABLE_MESS
AUTHOR
Theo Schlossnagle <jesus@cnds.jhu.edu>
SEE ALSO
- Various spread documentation at http://www.spread.org/.