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-setlock.html | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 doc/s6-setlock.html (limited to 'doc/s6-setlock.html') diff --git a/doc/s6-setlock.html b/doc/s6-setlock.html new file mode 100644 index 0000000..bab3e23 --- /dev/null +++ b/doc/s6-setlock.html @@ -0,0 +1,65 @@ + + + + + s6: the s6-setlock program + + + + + + +

+s6
+Software
+skarnet.org +

+ +

The s6-setlock program

+ +

+s6-setlock takes a lock on a file, then executes into another program. +

+ +

Interface

+ +

+     s6-setlock [ -n | -N | -t timeout ] [ -r | -w ] file prog...
+

+ +

s6-setlock creates file if it does not exist and opens it for writing.
It locks file. If it cannot take the lock for any reason, it exits 1.
It executes into prog....

+ +

Options

+ +

-n : nonblocking lock. If s6-setlock cannot acquire the lock, it will +exit 1 immediately.
-N : blocking lock. s6-setlock will wait until it can acquire the lock. +This is the default.
-t timeout : timed lock. If s6-setlock cannot acquire +the lock after timeout milliseconds, it will exit 1.

+ -r : shared lock. Other shared locks on the same file will not prevent +the lock from being acquired (but an exclusive lock will). + -w : exclusive lock. This is the default. +

+ + Notes + + + s6-setlock leaks an open file descriptor into the prog +execution. This is intended: the fd holds the lock, which is released +when prog exits. prog must not touch fds it does not +know about. + If the timed lock option is chosen, s6-setlock does not acquire the lock +itself. Instead, it spawns a s6lockd-helper +process that acquires the lock while s6-setlock controls the timeout; the +s6lockd-helper process then holds the lock and lives as long as +prog. + + + + -- cgit 1.4.1