From 90b12bd71bb9fc79a4640b9112c13ef529d0196a Mon Sep 17 00:00:00 2001 From: Laurent Bercot Date: Fri, 5 Dec 2014 22:26:11 +0000 Subject: Initial commit --- doc/s6-svwait.html | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 doc/s6-svwait.html (limited to 'doc/s6-svwait.html') diff --git a/doc/s6-svwait.html b/doc/s6-svwait.html new file mode 100644 index 0000000..6e15704 --- /dev/null +++ b/doc/s6-svwait.html @@ -0,0 +1,73 @@ + + + + + s6: the s6-svwait program + + + + + + +

+s6
+Software
+skarnet.org +

+ +

The s6-svwait program

+ +

+s6-svwait blocks until a collection of supervised services goes up, or down. +

+ +

+s6-svwait only waits for notifications; it never polls. +

+ +

Interface

+ +

+     s6-svwait [ -U | -u | -d ] [ -a | -o ] [ -t timeout ] servicedir...
+

+ +

+s6-svwait monitors one or more service +directories given as its arguments, waiting for a state (up or down) to +happen. It exits 0 when the wanted condition becomes true. +

+ +

Options

+ +

-u : up. s6-svwait will wait until the services are up, as +reported by s6-supervise. +This is the default; it is not reliable, but it does not depend on specific +support in the service programs. See this page +for details.
-U : really up. s6-svwait will wait until the services are +up, as reported by the services themselves. This requires specific support in the +service programs: see the explanation on this page.
-d : down. s6-svwait will wait until the services are down.
-o : or. s6-svwait will wait until one of the +given services comes up or down.
-a : and. s6-svwait will wait until all of the +given services come up or down. This is the default.
-t timeout : if the requested events have not +happened after timeout milliseconds, s6-svwait will print a message +to stderr and exit 1. By default, timeout is 0, which means no time +limit.

+ + +

Internals

+ +

+s6-svwait spawns a s6-ftrigrd child to +listen to notifications sent by s6-supervise. +It also checks supervise/status files to get the current service +states, so it is immune to race conditions. +

+ + + -- cgit v1.2.3