option to randomly kill xwords instances

xwords4/linux/scripts/sim_real.sh

@@ -8,6 +8,7 @@ PORT=${PORT:-10999}
 QUIT=${QUIT:-"-q 2"}
 USE_CURSES=${USE_CURSES:="yes"}
 WAIT_MAX=${WAIT_MAX:-10}
+KILL_INTERVAL_SECS=${KILL_INTERVAL_SECS:-0}
 
 RUN_NAME=$(basename $0)_$$
 
@@ -23,6 +24,9 @@ EOF
     echo "    env: HOST: remote host; default: localhost"
     echo "    env: PORT: remote port; default: 10999"
     echo "    env: WAIT_MAX: most seconds to wait between moves; default: 10"
+    echo "    env: KILL_INTERVAL_SECS: kill a random xwords every "
+    echo "         this many seconds; 0 to disable; cur: $KILL_INTERVAL_SECS"
+
     exit 0
 }
 
@@ -76,6 +80,23 @@ check_logs() {
     fi
 }
 
+kill_at_random() {
+    if [ -n "$KILL_INTERVAL_SECS" ]; then
+        if [ $KILL_INTERVAL_SECS -gt 0 ]; then
+            while [ -d /tmp/$RUN_NAME ]; do
+                sleep $KILL_INTERVAL_SECS
+                set $(pidof xwords)
+                shift $(($#/2))
+                PID=$1
+                if [ -n "$PID" ]; then
+                    echo "killing pid $PID"
+                    kill -INT $PID
+                fi
+            done
+        fi
+    fi
+}
+
 do_one() {
     CROOT=${1:-$(exec sh -c 'echo $PPID')}
     INDX=1
@@ -171,4 +192,6 @@ for II in $(seq $NRUNS); do
     do_one $II &
 done
 
+kill_at_random &
+
 wait