#! /bin/bash
#*******************************************************************************
# ALMA - Atacama Large Millimiter Array
# (c) European Southern Observatory, 2006
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
#
# "@(#) $Id: remoteMonitorProcess,v 1.1 2007/04/20 06:16:28 sharring Exp $"
#
# who       when      what
# --------  --------  ----------------------------------------------
# jdressel  2006-06-20  created
#

#************************************************************************
#   NAME  monitorProcess
#
#   SYNOPSIS  A tool to monitor the memory consumption of a process,
#             using the /proc filesystem.
#
#   DESCRIPTION  This program will generate a tab-separated datafile of
#                memory monitor points, and a gnuplot file to plot the
#                data directly.  Just run the process, run this monitoring
#                the process (as root with nice level -19 for sampling
#                consistency).  Kill this monitoring tool whenever you like,
#                then run gnuplot and do:
#                  gnuplot>  cd "/path/to/datafile/directory"
#                  gnuplot>  load "datafile.gnuplot"
#                to plot the data.
#
#   FILES
#
#   ENVIRONMENT
#
#   RETURN VALUES
#
#   CAUTIONS  If this program is not run as root with nice value of -19, then
#             the kernel scheduler with throttle the monitoring frequency if the
#             system is under high load.  Increasing the priority ensures consistent
#             monitoring under any load.
#
#             Also, due to the implementation of "sleep", it is a nondeterministic
#             interval that represents a lower sleep bound.  The actual interval will
#             vary slightly.  For instance, a monitor interval of 0.1 seconds will
#             actually record a datapoint every ~0.12 seconds.  The points are timestamped
#             carefully for this reason.
#
#   EXAMPLES  Default case (as root):  nice -n -19 monitorProcess PID#
#               This will monitor the process with pid PID# at an sampling interval
#               of 0.1 seconds.  It will dump a log file to ./PID#.log, and a gnuplot
#               file to ./PID#.log.gnuplot.
#
#             Finetuned case (as root):  nice -n -19 monitorProcess PID# INTERVAL 
#               This will monitor the process with pid PID# at a sampling interval
#               of INTERVAL seconds.  
#
#   SEE ALSO
#
#   BUGS
#
#------------------------------------------------------------------------
#

# PID of process to monitor passed in
if [ -z "$1" ]; then
  echo "Usage: $0 PID [frequency] [logfile]"
  exit 1
fi

if [ -d /proc/$1 ]; then
  declare -r PROCESS="$1"
else
  echo "The process $1 does not exist."
  exit 1
fi

# Temp mutable storage for return value
RETURN=""

# Date of start
DATE="`date \"+%F %H:%M:%S\"`"
# Frequency of monitoring defaults to ~10th of a second
if [ -n "$2" ]; then
  FREQUENCY="$2"
else
  FREQUENCY=0.1
fi

# Function to extract value from field "search"
getValue () {
  local info="$1"
  local search="$2"
  RETURN="`echo -e "$info" | grep "$2" | awk '{print $2}'`"
}

# Get the Process Name
getValue "`cat /proc/$PROCESS/status`" "Name"
processname="$RETURN"

echo -e "#Process: $processname , PID: $PROCESS" 
echo -e "#Time\tVmSize\tVmRSS\tVmData\tVmStk" 
while true ; do
  # Get timestamp to ns resolution (really reported at ms resolution)
  TIME="`date +%s.%N`"
  # Pull the process information from /proc
  INFO="`cat /proc/$PROCESS/status`"
  getValue "$INFO" "VmSize" 
  vmsize="$RETURN"
  getValue "$INFO" "VmRSS"
  vmrss="$RETURN"
  echo -e "$TIME\t$vmsize\t$vmrss"
  sleep $FREQUENCY
#  cycles=`expr $cycles + 1`
done