TakTuk - Perl module that provides an interface to taktuk(1) communication
facilities
use TakTuk;
my $rank = TakTuk::get('rank');
my $count = TakTuk::get('count');
print "I'm process $rank among $count\n";
if ($rank > 1) {
my ($from, $message) = TakTuk::recv();
if (not defined($message)) {
print "Trying to recv: ",
TakTuk::error_msg($TakTuk::error), "\n";
} else {
print "$rank received $message from $from\n";
}
}
sleep 1;
my $next = $rank+1;
$next = 1 if ($next > $count);
if (not TakTuk::send(to=>$next, body=>"[Salut numero $rank]")) {
print "Trying to send to $next: ",
TakTuk::error_msg($TakTuk::error), "\n";
}
if ($rank == 1) {
my ($from, $message) = TakTuk::recv(timeout=>5);
if (not defined($message)) {
print "Trying to recv :",
TakTuk::error_msg($TakTuk::error), "\n";
} else {
print "$rank received $message from $from\n";
}
}
The TakTuk communication layer Perl interface provides a way for programs
executed using the taktuk(1) command to exchange data. It is based on a
simple send/receive model using multicast-like sends and optionally timeouted
receives. This is only designed to be a control facility, in particular this
is not a high performance communication library.
The Perl communication interface for TakTuk is made of functions that can be
called by scripts executed using the taktuk_perl command of the TakTuk
engine (preferred way, less installation requirements on remote machines) or
using the TakTuk Perl module provided with the TakTuk distribution.
These functions are:
gets some information from TakTuk. Currently available information includes 'target', 'rank', 'count', 'father', 'child_min' and 'child_max'. This is a better way to get this information than environment variables as its takes into account renumbering that might occur after process spawn.
sends a scalar to a single peer or a set specification (see taktuk(1) for
information about set specifications). The two mandatory fields in the
arguments are to (with a set specification) and body. Optionally, a field
target might be given. Returns an undefined value upon error.
blocks until the reception of a message. Returns a list of two elements:
the logical number of the source of the message and the message itself.
Accepts an optional timeout argument with a numeric value.
Returns an empty list upon error.
When an error occur, all these functions set the variable $TakTuk::error
to the numeric code of the error that occured. A textual description of the
error is provided by the function TakTuk::error_msg($) that takes the error
code as an argument.
Error codes are the following :
a call to TakTuk::syswrite failed. This is due to a syswrite error
different than EAGAIN. The code should be accessible using $!.
the communication channel to the TakTuk engine has been closed. This typically occur when shutting down the logical network (using Ctrl-C on root node for instance).
TakTuk::recv only)a call to sysread failed (the code should be accessible using $!).
TakTuk::send only)to field missing in the arguments.
TakTuk::send only)body field missing in the arguments.
TakTuk::recv only)The call to TakTuk::recv timeouted. This only occur when giving a timeout
field as TakTuk::recv argument.
Finally, the TakTuk Perl module defines some constants which value match the
different states reported by the stream state (see taktuk(1) for details
about this stream). These constant are the following:
TakTuk::TAKTUK_READY TakTuk::TAKTUK_NUMBERED TakTuk::TAKTUK_TERMINATED TakTuk::CONNECTION_FAILED TakTuk::CONNECTION_INITIALIZED TakTuk::CONNECTION_LOST TakTuk::COMMAND_STARTED TakTuk::COMMAND_FAILED TakTuk::COMMAND_TERMINATED TakTuk::UPDATE_FAILED TakTuk::PIPE_STARTED TakTuk::PIPE_FAILED TakTuk::PIPE_TERMINATED TakTuk::FILE_RECEPTION_STARTED TakTuk::FILE_RECEPTION_FAILED TakTuk::FILE_RECEPTION_TERMINATED TakTuk::FILE_SEND_FAILED TakTuk::INVALID_TARGET TakTuk::NO_TARGET TakTuk::MESSAGE_DELIVERED TakTuk::INVALID_DESTINATION TakTuk::UNAVAILABLE_DESTINATION
tatkuk(1), taktukcomm(3), TakTuk::Pilot(3)
The original concept of TakTuk has been proposed by Cyrille Martin in his PhD thesis. People involved in this work include Jacques Briat, Olivier Richard, Thierry Gautier and Guillaume Huard.
The author of the version 3 (perl version) and current maintainer of the package is Guillaume Huard.
The TakTuk communication interface library is provided under the terms
of the GNU General Public License version 2 or later.