#!/bin/bash
#PBS -l nodes=1:ppn=1
#PBS -l walltime=1:00:00
#PBS -N example_job

cd $PBS_O_WORKDIR

# Add the module, just in case
module add DMTCP

# DMTCP communicates with our tasks through a socket. It uses port number
# 7779 by default, but if there are several DMTCP schedulers running on 
# the same node we will have problems. The best solution is to assign the
# port number manually. Also, if PORT=0, a random unused port will be 
# chosen, which is probably better.
PORT=7745

# Check if there is a previous script and run it if it's the case
# If not, just tell dmtcp_launch to run our script for us
if [ -e "dmtcp_restart_script.sh" ]
then    
    # We launch the restart script with the port number and also
    # with the name of the remote node. If the first time it was run
    # on node n1 but upon restart we are assigned node n2, it will
    # fail unless we add that switch.
    ./dmtcp_restart_script.sh -p ${PORT} -h $(hostname)
else
    # The -i switch tells dmtcp_launch the time in seconds between
    # checkpoints. Probably 60 is too small, so set it up accordingly.
    dmtcp_launch -i 60 -p ${PORT} ./my_job
fi