Ns atshutdown

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Man page: http://aolserver.com/docs/tcl/ns_atshutdown.html


NAME

ns_atshutdown - Queue a script to run when the server is shutting down

SYNOPSIS

ns_atshutdown script ?arg?

DESCRIPTION

This command queues a script to run when the server is shutting down. The script and optional arg are concatenated together and added to the list of shutdown callbacks. The scripts are executed in the global scope in LIFO (last in, first out) order.

EXAMPLES

Use ns_atsignal to stop long running processes. It seems that ns_atshutdown and ns_atexit are called after connection and scheduled threads have been killed, so those commands can not be used for that type of signal.

   # Create share variables for each signal
   foreach signal {SIGHUP TERM EXIT} {
       nsv_set . $signal 0
       ns_log notice "Listening for $signal"
   }
   proc heard_signal signal {
       nsv_set . $signal 1
       ns_log notice "Heard $signal"
   }
   ns_atsignal heard_signal SIGHUP
   ns_atshutdown heard_signal TERM
   ns_atexit heard_signal EXIT
   
   # Long running proc
   proc infinite_loop {} {
       set status "RUN"
       while {1} {
           # Do some work
           ns_sleep 1
           ns_log notice "infinite_loop working, status: $status"
           # Poll for signals
           foreach signal {SIGHUP TERM EXIT} {
               if {[nsv_get . $signal]} {
                   set status $signal
               }
           }
           if {$signal ne "RUN"} {
               break
           }
       }
       # Save work
       ns_log notice "infinite_loop stopped, status: $status"
   }
   ns_schedule_proc -thread -once 10 infinite_loop

Sample log file output from AOLserver 4.0.3 for ns_atsignal:

   [01/Aug/2006:10:30:56][1359.1][-main-] Notice: Heard SIGHUP
   [01/Aug/2006:10:30:56][1359.8][-sched:12-] Notice: infinite_loop stopped, status: SIGHUP
   [01/Aug/2006:10:30:56][1359.9][-conn:server::0] Notice: infinite_loop stopped, status: SIGHUP

Sample log file output from AOLserver 4.0.3 for ns_atshutdown and ns_atexit:

   [31/Jul/2006:15:57:52][3583.1][-main-] Notice: nsmain: AOLserver/4.0.3 stopping
   [31/Jul/2006:15:57:52][3583.1][-main-] Notice: serv: stopping server: server
   [31/Jul/2006:15:57:52][3583.1][-main-] Notice: serv: connection threads stopped
   [31/Jul/2006:15:57:52][3583.1][-main-] Notice: driver: shutdown complete
   [31/Jul/2006:15:57:52][3583.1][-main-] Notice: sched: shutdown pending
   [31/Jul/2006:15:57:52][3583.3][-sched-] Notice: sched: shutdown started
   [31/Jul/2006:15:57:52][3583.3][-sched-] Notice: sched: waiting for event threads...
   [31/Jul/2006:15:57:52][3583.8][-sched:idle0-] Notice: exiting
   [31/Jul/2006:15:57:52][3583.3][-sched-] Notice: sched: shutdown complete
   [31/Jul/2006:15:57:53][3583.9][-shutdown-] Notice: Heard TERM
   [31/Jul/2006:15:57:53][3583.9][-shutdown-] Notice: nslog: closing '/var/log/aolserver/server.log'
   [31/Jul/2006:15:57:53][3583.1][-main-] Notice: Heard EXIT

SEE ALSO

ns_atclose, ns_atexit, ns_atsignal


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