These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
Currently, sd-bus supports the ability to have thread-local default busses.
However, this is less useful than it can be since all functions which
require an sd_bus* as input require the caller to pass it. This patch adds
a new macro which allows the developer to pass a constant SD_BUS_DEFAULT,
SD_BUS_DEFAULT_USER or SD_BUS_DEFAULT_SYSTEM instead. This reduces work for
the caller.
For example:
r = sd_bus_default(&bus);
r = sd_bus_call_method(bus, ...);
sd_bus_unref(bus);
Becomes:
r = sd_bus_call_method(SD_BUS_DEFAULT, ...);
If the specified thread-local default bus does not exist, the function
calls will return -ENOPKG. No bus will ever be implicitly created.
Let's remove a number of synchronization points from our service
startups: let's drop synchronous match installation, and let's opt for
asynchronous instead.
Also, let's use sd_bus_match_signal() instead of sd_bus_add_match()
where we can.
If the server side kicks us from the bus, from our view no names are on the bus
anymore, hence let's make sure to dispatch all tracking objects immediately.
In order to add a name to a bus tracking object we need to do some bus
operations: we need to check if the name already exists and add match for it.
Both are synchronous bus calls. While processing those we need to make sure
that the tracking object is not dispatched yet, as it might still be empty, but
is not going to be empty for very long.
hence, block dispatching by removing the object from the dispatch queue while
adding it, and readding it on error.
This adds an optional "recursive" counting mode to sd_bus_track. If enabled
adding the same name multiple times to an sd_bus_track object is counted
individually, so that it also has to be removed the same number of times before
it is gone again from the tracking object.
This functionality is useful for implementing local ref counted objects that
peers make take references on.
Throughout the tree there's spurious use of spaces separating ++ and --
operators from their respective operands. Make ++ and -- operator
consistent with the majority of existing uses; discard the spaces.
GLIB has recently started to officially support the gcc cleanup
attribute in its public API, hence let's do the same for our APIs.
With this patch we'll define an xyz_unrefp() call for each public
xyz_unref() call, to make it easy to use inside a
__attribute__((cleanup())) expression. Then, all code is ported over to
make use of this.
The new calls are also documented in the man pages, with examples how to
use them (well, I only added docs where the _unref() call itself already
had docs, and the examples, only cover sd_bus_unrefp() and
sd_event_unrefp()).
This also renames sd_lldp_free() to sd_lldp_unref(), since that's how we
tend to call our destructors these days.
Note that this defines no public macro that wraps gcc's attribute and
makes it easier to use. While I think it's our duty in the library to
make our stuff easy to use, I figure it's not our duty to make gcc's own
features easy to use on its own. Most likely, client code which wants to
make use of this should define its own:
#define _cleanup_(function) __attribute__((cleanup(function)))
Or similar, to make the gcc feature easier to use.
Making this logic public has the benefit that we can remove three header
files whose only purpose was to define these functions internally.
See #2008.
This reverts commit d4d00020d6. The idea of
the commit is broken and needs to be reworked. We really cannot reduce
the bus-addresses to a single address. We always will have systemd with
native clients and legacy clients at the same time, so we also need both
addresses at the same time.
We should not fall back to dbus-1 and connect to the proxy when kdbus
returns an error that indicates that kdbus is running but just does not
accept new connections because of quota limits or something similar.
Using is_kdbus_available() in libsystemd/ requires it to move from
shared/ to libsystemd/.
Based on a patch from David Herrmann:
https://github.com/systemd/systemd/pull/886
Currently, the HASHMAP iterators stop at the first NULL entry in a
hashmap. This is non-obvious and breaks users like sd-device, which
legitimately store NULL values in a hashmap.
Fix all the iterators by taking a pointer to the value storage, instead of
returning it. The iterators now return a boolean that tells whether the
end of the list was reached.
Current users of HASHMAP_FOREACH() are *NOT* changed to explicitly check
for NULL. If it turns out, there were users that inserted NULL into
hashmaps, but didn't properly check for it during iteration, then we
really want to find those and fix them.
This should simplify the prototype a bit. The bus parameter is redundant
in most cases, and in the few where it matters it can be derived from
the message via sd_bus_message_get_bus().
This patch removes includes that are not used. The removals were found with
include-what-you-use which checks if any of the symbols from a header is
in use.
As a followup to 086891e5c1 "log: add an "error" parameter to all
low-level logging calls and intrdouce log_error_errno() as log calls
that take error numbers", use sed to convert the simple cases to use
the new macros:
find . -name '*.[ch]' | xargs sed -r -i -e \
's/log_(debug|info|notice|warning|error|emergency)\("(.*)%s"(.*), strerror\(-([a-zA-Z_]+)\)\);/log_\1_errno(-\4, "\2%m"\3);/'
Multi-line log_*() invocations are not covered.
And we also should add log_unit_*_errno().
Clean up the function namespace by renaming the following:
sd_bus_get_owner_uid() → sd_bus_get_name_creds_uid()
sd_bus_get_owner_machine_id() → sd_bus_get_name_machine_id()
sd_bus_get_peer_creds() → sd_bus_get_owner_creds()
It is redundant to store 'hash' and 'compare' function pointers in
struct Hashmap separately. The functions always comprise a pair.
Store a single pointer to struct hash_ops instead.
systemd keeps hundreds of hashmaps, so this saves a little bit of
memory.
This makes callback behaviour more like sd-event or sd-resolve, and
creates proper object for unregistering callbacks.
Taking the refernce to the slot is optional. If not taken life time of
the slot will be bound to the underlying bus object (or in the case of
an async call until the reply has been recieved).
GCC optimizes strlen("string constant") to a constant, even with -O0.
Thus, replace patterns like sizeof("string constant")-1 with
strlen("string constant") where possible, for clarity. In particular,
for expressions intended to add up the lengths of components going into
a string, this often makes it clearer that the expression counts the
trailing '\0' exactly once, by putting the +1 for the '\0' at the end of
the expression, rather than hidden in a sizeof in the middle of the
expression.
This is primarily useful for services that need to track clients which
reference certain objects they maintain, or which explicitly want to
subscribe to certain events. Something like this is done in a large
number of services, and not trivial to do. Hence, let's unify this at
one place.
This also ports over PID 1 to use this to ensure that subscriptions to
job and manager events are correctly tracked. As a side-effect this
makes sure we properly serialize and restore the track list across
daemon reexec/reload, which didn't work correctly before.
This also simplifies how we distribute messages to broadcast to the
direct busses: we only track subscriptions for the API bus and
implicitly assume that all direct busses are subscribed. This should be
a pretty OK simplification since clients connected via direct bus
connections are shortlived anyway.
