#!/bin/sh

if [ $# != 5 ]
then
	echo "usage: $0 <glexec> <proxy> <sandbox> <max-glexec-retries> <min-glexec-retry-delay>" >&2
	exit 1
fi

GLEXEC="$1"
PROXY="$2"
SANDBOX="$3"
MAX_GLEXEC_ERRORS="$4"
MIN_GLEXEC_RETRY_DELAY="$5"

# tar up the contents of the user-owned sandbox and pipe them
# back to a process running as the condor user. make sure not to
# stomp on the condor-owned copy of the user proxy
#
SH=`readlink -f /bin/sh`
GLEXEC_CLIENT_CERT="$SANDBOX.condor/$PROXY"
export GLEXEC_CLIENT_CERT
# prevent glexec from creating a proxy in /tmp that is not cleaned up
GLEXEC_TARGET_PROXY=/dev/null
export GLEXEC_TARGET_PROXY

glexec_errors=0
while [ 1 ]; do
  { "$GLEXEC" "$SH" -c "rm -f \"$SANDBOX/$PROXY\" && \
                        tar -C \"$SANDBOX\" -c . && \
                        rm -rf \"$SANDBOX\"";
    echo $? > "$SANDBOX.condor/_condor_glexec_rc"
  } | tar -C "$SANDBOX.condor" -x

  tar_rc=$?
  glexec_rc=$(cat "$SANDBOX.condor/_condor_glexec_rc")
  rm -f "$SANDBOX.condor/_condor_glexec_rc"
  if [ "$glexec_rc" = "" ]; then
    glexec_rc=2
  fi

  if [ $glexec_rc -eq 0 ]; then
    break
  elif [ $glexec_rc -ne 202 ] && [ $glexec_rc -ne 203 ]; then
    # Either a non-transient glexec error, or an error from the command
    # we are asking glexec to run.  Try to finish cleaning up
    # and then exit non-zero at the end.
    break
  fi

  # This _could_ be a transient issue, such as a communication error with GUMS,
  # so retry up to some limit.
  glexec_errors=$(( $glexec_errors + 1 ))
  if [ $glexec_errors -gt $MAX_GLEXEC_ERRORS ]; then
    break
  fi

  # truncated exponential backoff
  # sleep for X * min(100,1+random_number_in_range(0,glexec_errors-1))
  delay_rand=$(( (1 + 0x0$(hexdump -n 4 -e '"%4x\n"' /dev/urandom) % $glexec_errors) % 100 ))
  delay=$(( $MIN_GLEXEC_RETRY_DELAY * $delay_rand ))
  echo "Glexec exited with status $glexec_rc; retrying in $delay seconds." >&2
  sleep $delay
done

# move the condor-owned sandbox back in place
#
mv -f "$SANDBOX.condor" "$SANDBOX"

mv_rc=$?

if [ $mv_rc -ne 0 ] || [ $tar_rc -ne 0 ] || [ $glexec_rc -ne 0 ]; then
  exit 1
fi