TakTuk - Perl module that provides an interface to "taktuk(1)" communication facilities

       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.

perl v5.38.2                                       2024-04-01                                        TakTuk(3pm)

       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:

       TakTuk::get($)
           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.

       TakTuk::send(%)
           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.

       TakTuk::recv(%)
           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 $TakTuk::error to the numeric code of the error
       that  occurred.  A textual description of the error is provided by the function TakTuk::error_msg($) that
       takes the error code as an argument.

       Error codes are the following :

       TakTuk::ESWRIT
           a call to "TakTuk::syswrite" failed. This is due to a "syswrite" error different than  "EAGAIN".  The
           code should be accessible using $!.

       TakTuk::EFCLSD
           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::ESREAD ("TakTuk::recv" only)
           a call to "sysread" failed (the code should be accessible using $!).

       TakTuk::EARGTO ("TakTuk::send" only)
           "to" field missing in the arguments.

       TakTuk::EARGBD ("TakTuk::send" only)
           "body" field missing in the arguments.

       TakTuk::ETMOUT ("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

       TakTuk - Perl module that provides an interface to "taktuk(1)" communication facilities

tatkuk(1), taktukcomm(3), TakTuk::Pilot(3)

         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";
             }
         }