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/libs6lock/s6lockd-helper.html | 52 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 doc/libs6lock/s6lockd-helper.html (limited to 'doc/libs6lock/s6lockd-helper.html') diff --git a/doc/libs6lock/s6lockd-helper.html b/doc/libs6lock/s6lockd-helper.html new file mode 100644 index 0000000..839dce4 --- /dev/null +++ b/doc/libs6lock/s6lockd-helper.html @@ -0,0 +1,52 @@ + + + + + s6: the s6lockd-helper internal program + + + + + + +libs6lock
+s6
+Software
+skarnet.org

+ +

The `s6lockd-helper` program

+ +

+s6lockd-helper is a helper program for the s6lock daemon. +It just acquires a lock and holds it until it is killed or told to +exit by its parent daemon. +

+ +

Interface

+ +

+ s6lockd-helper is not meant to be invoked directly by the user: +it will be spawned by the +s6lockd program. +

+ +

Notes

+ +

s6lockd-helper blocks on lock acquisition until it succeeds. It then +notifies its parent. It exits when its parent tells him to (i.e. when the +client asks for lock release). During the lock acquisition phase, it can +be killed if its parent detects a timeout.
One s6lockd-helper process per lock is the only way (apart from +threads) to implement timed lock acquisition. This can lead to a lot of +s6lockd-helper processes, but this is not a problem: +
- Processes are not a scarce resource. Today's schedulers work in O(1), +i.e. a sleeping process takes no scheduling time at all.
- s6lockd-helper is extremely tiny. Every instance should use up at +most one or two pages of non-sharable memory.

+ + + -- cgit v1.2.3

The s6lockd-helper program

Interface

Notes

The `s6lockd-helper` program