@@ -69,6 +69,7 @@ Bit Description
-----------------------------------------------------------------
0 Ring reconnection (see the ring reconnection feature below)
1 Connection error indicator (see connection error feature below)
+2 WATCH can take a third parameter limiting its scope
The "Connection state" field is used to request a ring close and reconnect.
The "Connection state" field only contains valid data if the server has
@@ -187,7 +187,7 @@ SET_PERMS <path>|<perm-as-string>|+?
---------- Watches ----------
-WATCH <wpath>|<token>|?
+WATCH <wpath>|<token>|[<depth>|]?
Adds a watch.
When a <path> is modified (including path creation, removal,
@@ -198,7 +198,11 @@ WATCH <wpath>|<token>|?
matching watch results in a WATCH_EVENT message (see below).
The event's path matches the watch's <wpath> if it is an child
- of <wpath>.
+ of <wpath>. This match can be limited by specifying <depth> (a
+ decimal value of 0 or larger): it denotes the directory levels
+ below <wpath> to consider for a match ("0" would not match for
+ a child of <wpath>, "1" would match only for a direct child,
+ etc.).
<wpath> can be a <path> to watch or @<wspecial>. In the
latter case <wspecial> may have any syntax but it matches
@@ -209,7 +213,13 @@ WATCH <wpath>|<token>|?
shutdown, and also on RELEASE
and domain destruction
<wspecial> events are sent to privileged callers or explicitly
- via SET_PERMS enabled domains only.
+ via SET_PERMS enabled domains only. The semantics for a
+ specification of <depth> differ for generating <wspecial>
+ events: specifying "1" will report the related domid by using
+ @<wspecial>/<domid> for the reported path. Other <depth>
+ values are not supported.
+ For @releaseDomain it is possible to watch only for a specific
+ domain by specifying @releaseDomain/<domid> for the path.
When a watch is first set up it is triggered once straight
away, with <path> equal to <wpath>. Watches may be triggered
Add documentation for an extension of the WATCH command used to limit the scope of watched paths. Additionally it enables to receive more information in the events related to special watches (@introduceDomain or @releaseDomain). Signed-off-by: Juergen Gross <jgross@suse.com> --- This will probably need an extension of the Xenstore migration protocol, too. --- docs/misc/xenstore-ring.txt | 1 + docs/misc/xenstore.txt | 16 +++++++++++++--- 2 files changed, 14 insertions(+), 3 deletions(-)