From b750101eb236130cf056c675997decbac904cc49 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 17:35:18 +0200 Subject: Adding upstream version 252.22. Signed-off-by: Daniel Baumann --- man/sd_watchdog_enabled.xml | 142 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 142 insertions(+) create mode 100644 man/sd_watchdog_enabled.xml (limited to 'man/sd_watchdog_enabled.xml') diff --git a/man/sd_watchdog_enabled.xml b/man/sd_watchdog_enabled.xml new file mode 100644 index 0000000..1abc2f8 --- /dev/null +++ b/man/sd_watchdog_enabled.xml @@ -0,0 +1,142 @@ + + + + + + + + sd_watchdog_enabled + systemd + + + + sd_watchdog_enabled + 3 + + + + sd_watchdog_enabled + Check whether the service manager expects watchdog keep-alive notifications from a service + + + + + #include <systemd/sd-daemon.h> + + + int sd_watchdog_enabled + int unset_environment + uint64_t *usec + + + + + + Description + sd_watchdog_enabled() may be called by + a service to detect whether the service manager expects regular + keep-alive watchdog notification events from it, and the timeout + after 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). 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 write the timeout + in µs for the watchdog logic to it. + + To enable service supervision with the watchdog logic, use + WatchdogSec= in service files. See + systemd.service5 + for details. + + Use + sd_event_set_watchdog3 + to enable automatic watchdog support in + sd-event3-based event loops. + + + + Return Value + + On failure, this call returns a negative errno-style error + code. If the service manager expects watchdog keep-alive + notification messages to be sent, > 0 is returned, otherwise 0 + is returned. Only if the return value is > 0, the + usec parameter is valid after the + call. + + + + Notes + + + + Internally, this function parses the + $WATCHDOG_PID and + $WATCHDOG_USEC environment variable. The call + will ignore these variables if $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. + + + + Environment + + + + $WATCHDOG_PID + + Set by the system manager for supervised + process for which watchdog support is enabled, and contains + the PID of that process. See above for + details. + + + + $WATCHDOG_USEC + + Set by the system manager for supervised + process for which watchdog support is enabled, and contains + the watchdog timeout in µs. See above for + details. + + + + + + See Also + + systemd1, + sd-daemon3, + daemon7, + systemd.service5, + sd_notify3, + sd_event_set_watchdog3 + + + + -- cgit v1.2.3