The lz4 functions are only used in test-compress.c, so let's just
put the declarations and includes in there instead of having everyone
including compress.h pull in the lz4 headers.
Instead of unconditionally including sys/param.h in
macro-fundamental.h which itself includes a bunch of other unnecessary
headers, let's override it with an empty file to avoid it from overriding
our MAX() macro. We can't make including it an error as it's included (
for seemingly no good reason) by <resolv.h>.
Just downgrade the log message in case of ENOENT of agent binaries to
LOG_DEBUG. Do this in order to support distros which split off some
agent bianries into separate optional binaries.
Fixes: #37369
On Linux, read() on a message queue descriptor returns the message
queue statistics, not the actual message queue data. We need to use
mq_receive() to drain the queues instead.
Fixes a problem where a POSIX message queue socket unit with messages
in the queue at shutdown time could result in a hang on reboot/shutdown.
Otherwise, initrd-cleanup.service requests isolation thus the socket
is stopped before switching root, and several early events after
switching root may be lost.
As a test, it just increases our code coverage in a fake way.
When run manually, it can be used to conveniently print what logind
thinks about various processes:
$ build/test-sd-login
sd_pid_get_session(0) → No data available
sd_pid_get_unit(0) → user@1000.service
sd_pid_get_user_unit(0) → app-ghostty-transient-5088.scope
sd_pid_get_machine_name(0) → No such file or directory
sd_pid_get_slice(0) → user-1000.slice
sd_pid_get_user_slice(0) → app.slice
sd_pid_get_owner_uid(0) → 1000
sd_pid_get_cgroup(0) → /user.slice/user-1000.slice/user@1000.service/app.slice/app-ghostty-transient-5088.scope/surfaces/556FAF50BA40.scope
$ build/test-sd-login cgroup 1
sd_pid_get_cgroup(1) → /init.scope
The existing text grew organically as features were added and was
not very organized. Reorder it and break into paragraphs grouped
by topic. The description of the :errno syntax is replaced by a short
reference to the SystemCallErrorNumber= setting. This makes the
text shorter and makes it easier to explain how the two settings combine.
