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Diffstat (limited to 'doc/servicedir.html')
| -rw-r--r-- | doc/servicedir.html | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/doc/servicedir.html b/doc/servicedir.html index a49a38d..f08c3a4 100644 --- a/doc/servicedir.html +++ b/doc/servicedir.html @@ -46,7 +46,7 @@ but most of the time it will be a script, called <em>run script</em>. This file is the most important one in your service directory: it contains the commands that will setup and run your <em>foo</em> service. <ul> - <li> It is forked and executed by <a href="s6-supervise.html">s6-supervise</a> + <li> It is spawned by <a href="s6-supervise.html">s6-supervise</a> every time the service must be started, i.e. normally when <a href="s6-supervise.html">s6-supervise</a> starts, and whenever the service goes down when it is supposed to be up. </li> @@ -118,11 +118,16 @@ process has been killed. If the <em>foo</em> service is supposed to be up, script, not the finish script, should be running; the finish script should really be short-lived.) The maximum duration of a <tt>finish</tt> execution can be configured via the <tt>timeout-finish</tt> file, see below. </li> - <li> The finish script is executed with three arguments: + <li> The finish script is executed with four arguments: <ol> <li> the exit code from the run script (resp. 256 if the run script was killed by a signal) </li> <li> an undefined number (resp. the number of the signal that killed the run script) </li> - <li> the name of the service directory, the same that has been given to <tt>./run</tt>. </li> + <li> the name of the service directory, the same that has been given to <tt>./run</tt> </li> + <li> the process group id of the defunct run script. This is useful to clean up +services that leave children behind: for instance, <tt>if test "$1" -gt 255 ; then kill -9 -- -"$4" ; fi</tt> +in the finish script will SIGKILL all children processes if the service crashed. +This is not an entirely reliable mechanism, because an annoying service could spawn +children processes in a different process group, but it should catch most offenders. </li> </ol> <li> If the finish script exits 125, then <a href="s6-supervise.html">s6-supervise</a> interprets this as a permanent failure for the service, and does not restart it, |