X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=man%2Fsd_watchdog_enabled.xml;h=297878d814dfb7495293c7c2211a6ce189aa1331;hb=a03fe1a5d56be86fcc383090e191224590a1ab5d;hp=41640276405080abeb041d31cbb13ca536ee06c9;hpb=b1317b34f4cf93fdae91a3b5aee1039ce7cf80f5;p=elogind.git
diff --git a/man/sd_watchdog_enabled.xml b/man/sd_watchdog_enabled.xml
index 416402764..297878d81 100644
--- a/man/sd_watchdog_enabled.xml
+++ b/man/sd_watchdog_enabled.xml
@@ -69,30 +69,37 @@
which the manager will act on the service if it did
not get such a notification.
+ If the $WATCHDOG_USEC
+ environment variable is set, and the
+ $WATCHDOG_PID variable is unset or
+ set to the PID of the current process, the service
+ manager expects notifications from this process. The
+ manager will usually terminate a service when it does
+ not get a notification message within the specified
+ time after startup and after each previous message. It
+ is recommended that a daemon sends a keep-alive
+ notification message to the service manager every half
+ of the time returned here. Notification messages may
+ be sent with
+ sd_notify3
+ with a message string of
+ WATCHDOG=1.
+
If the unset_environment
parameter is non-zero,
sd_watchdog_enabled() will unset
the $WATCHDOG_USEC and
$WATCHDOG_PID environment variables
- before returning (regardless of whether the function call
- itself succeeded or not). Further calls to
- sd_watchdog_enabled() will then
- return with zero, but the variable is no longer
- inherited by child processes.
+ before returning (regardless of whether the function
+ call itself succeeded or not). Those variables are no
+ longer inherited by child processes. Further calls to
+ sd_watchdog_enabled() will also
+ return with zero.
If the usec parameter is
non-NULL, sd_watchdog_enabled()
- will return the timeout in µs for the watchdog
- logic. The service manager will usually terminate a
- service when it did not get a notification message
- within the specified time after startup and after each
- previous message. It is recommended that a daemon
- sends a keep-alive notification message to the service
- manager every half of the time returned
- here. Notification messages may be sent with
- sd_notify3
- with a message string of
- WATCHDOG=1.
+ will write the timeout in µs for the watchdog
+ logic to it.
To enable service supervision with the watchdog
logic, use WatchdogSec= in service
@@ -122,11 +129,10 @@
$WATCHDOG_PID and
$WATCHDOG_USEC environment
variable. The call will ignore these variables if
- $WATCHDOG_PID does containe the PID
+ $WATCHDOG_PID does not contain the PID
of the current process, under the assumption that in
that case, the variables were set for a different
process further up the process tree.
-
@@ -156,6 +162,19 @@
+
+ History
+
+ The watchdog functionality and the
+ $WATCHDOG_USEC variable were
+ added in systemd-41.
+
+ sd_watchdog_enabled()
+ function was added in systemd-209. Since that version
+ the $WATCHDOG_PID variable is also
+ set.
+
+
See Also