From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 15 Aug 2016 16:12:01 +0000 (+0200)
Subject: core: add Ref()/Unref() bus calls for units
X-Git-Tag: v232.2~93
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=87a9605f2154237a49d3da054cad782dfcc1d2d2;p=elogind.git

core: add Ref()/Unref() bus calls for units

This adds two (privileged) bus calls Ref() and Unref() to the Unit interface.
The two calls may be used by clients to pin a unit into memory, so that various
runtime properties aren't flushed out by the automatic GC. This is necessary
to permit clients to race-freely acquire runtime results (such as process exit
status/code or accumulated CPU time) on successful service termination.

Ref() and Unref() are fully recursive, hence act like the usual reference
counting concept in C. Taking a reference is a privileged operation, as this
allows pinning units into memory which consumes resources.

Transient units may also gain a reference at the time of creation, via the new
AddRef property (that is only defined for transient units at the time of
creation).
---

diff --git a/src/libelogind/sd-bus/bus-common-errors.c b/src/libelogind/sd-bus/bus-common-errors.c
index e38e2e0dc..d73b8faea 100644
--- a/src/libelogind/sd-bus/bus-common-errors.c
+++ b/src/libelogind/sd-bus/bus-common-errors.c
@@ -46,6 +46,7 @@ BUS_ERROR_MAP_ELF_REGISTER const sd_bus_error_map bus_common_errors[] = {
         SD_BUS_ERROR_MAP(BUS_ERROR_SHUTTING_DOWN,                ECANCELED),
         SD_BUS_ERROR_MAP(BUS_ERROR_SCOPE_NOT_RUNNING,            EHOSTDOWN),
         SD_BUS_ERROR_MAP(BUS_ERROR_NO_SUCH_DYNAMIC_USER,         ESRCH),
+        SD_BUS_ERROR_MAP(BUS_ERROR_NOT_REFERENCED,               EUNATCH),
 
         SD_BUS_ERROR_MAP(BUS_ERROR_NO_SUCH_MACHINE,              ENXIO),
         SD_BUS_ERROR_MAP(BUS_ERROR_NO_SUCH_IMAGE,                ENOENT),