introduced a shutdown grace period defaulting to 5 minutes

README.md

@@ -10,6 +10,6 @@ This will tag all VMs with the priority of 0 which will leave them <strong>stopp
 
 ...and so on. Informational messages are logged via the syslog facility as '<i>daemon.notice</i>' entries tracking the determined order as well as the outcome for every step taken. The solution comprises two services backed by the same single method script: one activated before <i>svc:/system/zones</i> in order to convince it not to start any guests and the actual payload starting once vmadmd is available to evaluate the tags and complete the sequence.
 
-SMF will import the manifests for the services upon boot-up when it initializes its repository. The location of the method script is configurable via the service property <i>config/method_prefix</i>, defaulting to <strong><i>/opt/custom/bin</i></strong>. The start-up delay defaults to <strong><i>30</i></strong> seconds, also configurable via the context environment variable <i>DELAY</i> for the method <i>start</i>.
+SMF will import the manifests for the services upon boot-up when it initializes its repository. The location of the method script is configurable via the service property <i>config/method_prefix</i>, defaulting to <strong><i>/opt/custom/bin</i></strong>. The start-up delay defaults to <strong><i>30</i></strong> seconds, also configurable via the context environment variable <i>DELAY</i> for the method <i>start</i>. A grace period of <strong>5</strong> minutes is granted for shut-down, configurable via the context environment variable <i>GRACE_PERIOD</i> in the <i>stop</i> method.
 
 In the future the method script might get re-written in node.js in order to make a more human-friendly dependency notation/handling possible. This is merely the shortest path.

guesthandler.xml

@@ -14,7 +14,13 @@
         </method_environment>
       </method_context>
     </exec_method>
-    <exec_method name='stop' type='method' exec='%{config/method_prefix}/svc-guesthandler %m' timeout_seconds='0'/>
+    <exec_method name='stop' type='method' exec='%{config/method_prefix}/svc-guesthandler %m' timeout_seconds='0'>
+      <method_context>
+        <method_environment>
+          <envvar name='GRACE_PERIOD' value='300'/>
+        </method_environment>
+      </method_context>
+    </exec_method>
     <property_group name='startd' type='framework'>
       <propval name='duration' type='astring' value='transient'/>
     </property_group>

svc-guesthandler

@@ -5,8 +5,8 @@
 
 if [ -z $SMF_FMRI ];
 	then
-    		print "this script can only be invoked by smf(5)"
-    		exit $SMF_EXIT_ERR_NOSMF
+		print "this script can only be invoked by smf(5)"
+		exit $SMF_EXIT_ERR_NOSMF
 fi
 
 ME=${0##*/svc-}
@@ -58,6 +58,18 @@ case $1 in
 						log $UUID failed to $1
 				fi
 			done
+
+		# grant the guests some time to shut down
+		WAIT_UNTIL=$(($(date +%s) + ${GRACE_PERIOD:-300}))
+		while [ $(zoneadm list | wc -l) -gt 1 ];
+			do
+				if [ $(date +%s) -le $WAIT_UNTIL ];
+					then
+						sleep 1
+					else
+						exit $SMF_EXIT_ERR_FATAL
+				fi
+			done
 	;;
 
 	disarm)