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Diffstat (limited to 'doc/s6-svscan.html')
| -rw-r--r-- | doc/s6-svscan.html | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/doc/s6-svscan.html b/doc/s6-svscan.html index 7649abd..4bb943b 100644 --- a/doc/s6-svscan.html +++ b/doc/s6-svscan.html @@ -200,7 +200,7 @@ uses <a href="s6-svscanctl.html">s6-svscanctl -n</a>), but inactive s6-supervise processes will not be restarted if they die. </p> -<h2> Implementation notes </h2> +<h2> Notes </h2> <ul> <li> s6-svscan is designed to run until the machine is shut down. It is @@ -220,6 +220,19 @@ to guarantee that s6-svscan does not use heap memory at all.</small> </li> <li> When run with the <tt>-t0</tt> option, s6-svscan <em>never polls</em>, it only wakes up on notifications, just like s6-supervise. The s6 supervision tree can be used in energy-critical environments. </li> + <li> The supervision tree (i.e. the tree of processes made of s6-svscan and +all its scions) is not supposed to have a controlling terminal; s6-svscan +generally is either process 1 or a child of process 1, not something that is +launched from a terminal. If you run s6-svscan from an interactive shell, be +warned that typing ^C in the controlling terminal (which sends a SIGINT to +all processes in the foreground process group in the terminal) will terminate +the supervision tree, but not the supervised processes - so, the supervised +processes will keep running as orphans. This is by design: supervised +processes should be as resilient as possible, even when their supervisors +die. However, if you want to launch s6-svscan from an interactive shell and +need your services to die with the supervision tree when you ^C it, you can +obtain this behaviour by creating <tt>./nosetsid</tt> files in every +<a href="servicedir.html">service directory</a>. </li> </ul> </body> |