From b8af9fd65b697e9bb77a32d1a6a70367814aaed5 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Mon, 1 Apr 2019 17:30:45 +0200 Subject: [PATCH] man: be clearer that .timer time expressions need to be reset to override them let's be clearer about the overriding concept for OnCalendar= settings. Prompted by this thread: https://lists.freedesktop.org/archives/systemd-devel/2019-March/042351.html (cherry picked from commit 58031d99c6320855b86f4890baa9165597e3d841) Resolves: #1816908 --- man/systemd.timer.xml | 31 ++++++++++++++++++------------- 1 file changed, 18 insertions(+), 13 deletions(-) diff --git a/man/systemd.timer.xml b/man/systemd.timer.xml index 44b257c745..ebc1df89f1 100644 --- a/man/systemd.timer.xml +++ b/man/systemd.timer.xml @@ -125,12 +125,12 @@ to when the unit the timer is activating was last deactivated. - Multiple directives may be combined of the same and of - different types. For example, by combining - OnBootSec= and - OnUnitActiveSec=, it is possible to define - a timer that elapses in regular intervals and activates a - specific service each time. + Multiple directives may be combined of the same and of different types, in which case the timer + unit will trigger whenever any of the specified timer expressions elapse. For example, by combining + OnBootSec= and OnUnitActiveSec=, it is possible to define a + timer that elapses in regular intervals and activates a specific service each time. Moreover, both + monotonic time expressions and OnCalendar= calendar expressions may be combined in + the same timer unit. The arguments to the directives are time spans configured in seconds. Example: "OnBootSec=50" means 50s after @@ -145,13 +145,12 @@ and the configured unit is started. This is not the case for timers defined in the other directives. - These are monotonic timers, independent of wall-clock - time and timezones. If the computer is temporarily suspended, - the monotonic clock stops too. + These are monotonic timers, independent of wall-clock time and timezones. If the computer is + temporarily suspended, the monotonic clock pauses, too. - If the empty string is assigned to any of these options, - the list of timers is reset, and all prior assignments will - have no effect. + If the empty string is assigned to any of these options, the list of timers is reset (both + monotonic timers and OnCalendar= timers, see below), and all prior assignments + will have no effect. Note that timers do not necessarily expire at the precise time configured with these settings, as they are @@ -175,7 +174,13 @@ the AccuracySec= setting below. - May be specified more than once. + May be specified more than once, in which case the timer unit will trigger whenever any of the + specified expressions elapse. Moreover calendar timers and monotonic timers (see above) may be + combined within the same timer unit. + + If the empty string is assigned to any of these options, the list of timers is reset (both + OnCalendar= timers and monotonic timers, see above), and all prior assignments + will have no effect.