make "Unprotected concurrency introduces some true randomness." be true;
this code is called often and doesn't need to be considered critical. I added CRITICAL by mistake.
#!/usr/bin/env bash
#
# Author: Makarius
#
# DESCRIPTION: remove named pipe
PRG="$(basename "$0")"
function usage()
{
echo
echo "Usage: isabelle $PRG NAME"
echo
echo " Remove an unused named pipe, after producing dummy output"
echo " to unblock the reader (blocks if no reader present)."
echo
exit 1
}
## main
[ "$#" != 1 ] && usage
FIFO="$1"; shift
if [ -p "$FIFO" ]; then
echo -n "" >"$FIFO" && rm -f "$FIFO"
fi