This PR makes things around connection factories a little more consistent and more intuitive:
* createConnection() has been removed. One shall call more expressive createSystemConnection() instead to get a connection to the system bus.
* createDefaultBusConnection() has been renamed to createBusConnection(), so as not to be confused with libsystemd's default_bus, which is a different thing (a reusable thread-local bus).
Proxies still by default call createBusConnection() to get a connection when the connection is not provided explicitly by the caller, but now createBusConnection() does a different thing, so now the proxies connect to either session bus or system bus depending on the context (as opposed to always to system bus like before).
This switches from a raw pointer to std::optional type to pass prospective call errors to the client (using std::optional was not possible years back when sdbus-c++ was based on C++14). This makes the API a little clearer, safer, idiomatically more expressive, and removes potential confusion associated with raw pointers (like ownership, lifetime questions, etc.).
This makes D-Bus proxy signal registration more flexible, more dynamic, and less error-prone since no `finishRegistration()` call is needed. A proxy can register to a signal at any time during its lifetime, and can unregister freely by simply destroying the associated slot.
This improves the D-Bus object API registration/unregistration by making it more flexible, more dynamic, closer to sd-bus API design but still on high abstraction level, and -- most importantly -- less error-prone since no `finishRegistration()` call is needed anymore.
sd_bus_match_signal() is more convenient than more general sd_bus_add_match() for signal registration, and requires less code on our side. Plus, systemd of at least v238 is required for sdbus-c++ v2, and this version already ships with sd_bus_match_signal().
Since synchronous D-Bus calls are simplified in v2.0 and no more implemented in terms of an async call, the issue reported in #362 is no more relevant, and we can return to the simple boolean flag for indicating a finished call.
Signatures of callbacks async_reply_handler, signal_handler, message_handler and property_set_callback were modified to take input message objects by value, as opposed to non-const ref.
The callee assumes ownership of the message. This API is more idiomatic, more expressive, cleaner and safer. Move semantics is used to pass messages to the callback handlers. In some cases, this also improves performance.
In case a signal arrives during the `RequestName` or `ReleaseName` D-Bus call (which is a synchronous call), the signal may not be processed immediately, which is a bug. This is solved now by waking up the event loop.
* chore: Use std::exchange in UnixFd
This was suggested in code review for #376 .
* fix: Protect against UnixFd self-assignment
While self-assignment is rare, it is expected to be safe. Add a check
to prevent putting the object in an invalid state.
* fix: Improve hygiene around dup system call
- Don't try to call dup on a negative value.
- Check dup return code and throw if it fails, rather than returning an
empty UnixFd object.
* chore: Move UnixFd::close to Types.cpp
Minor convenience for applications: unistd.h doesn't have to be included
in the public header.
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Co-authored-by: David Reiss <dreiss@meta.com>
* Catch and process all exceptions (not just sdbus::Error) from callback handlers
* Unify handling of exceptions from all types of callbacks -- always set sd_bus_error and return a negative result number in case of exception
Although libsystemd logs (with DEBUG severity) all errors from such callback handlers (except method callback handler), it seems to be out of our control. One of handy sdbus-c++ features could be the ability for clients to install a log callback, which sdbus-c++ would call in case of exceptions flying from callback handlers. In case something doesn't work for clients (especially novices), they can first look into these logs.
This may be handy in common situations like ignored signals on client side because of the inadvertent mismatch between real signal signature and signal handler signature. Like here: #373. (Although in this specific case of signals, there is a solution with an additional const sdbus::Error* argument that would reveal such an error.)
* fix: Use-after-return in synchronous calls
This bug was introduced by c39bc637b8 and can be reproduced by
configuring with
cmake -S . -B build -DBUILD_TESTS=yes -DCMAKE_CXX_COMPILER=clang++ \
-DCMAKE_CXX_FLAGS="-Wno-error=deprecated-copy -fno-omit-frame-pointer -fsanitize=address -fsanitize-address-use-after-scope"
and running `cmake --buid build && cmake --build build -t test` or
`build/tests/sdbus-c++-integration-tests --gtest_filter=SdbusTestObject.HandlesCorrectlyABulkOfParallelServerSideAsyncMethods`
The issue is that `sdbus_async_reply_handler` can call `removeCall`, which
writes to `data->finished`, but `data` can point to the stack of
`sendMethodCallMessageAndWaitForReply`, which can return as soon as
`asyncCallData->callback` is called.
As a fix, I restored some of the logic removed in c39bc637b8.
Specifically, in `sdbus_async_reply_handler`, I make a copy of some data
from `asyncCallData` (a new `state` field instead of `slot`), and in the
`SCOPE_GUARD`, I don't call `removeCall` if the call was actually
synchronous.
* refactor: use enum class instead of int
---------
Co-authored-by: David Reiss <dreiss@meta.com>
Co-authored-by: Stanislav Angelovič <stanislav.angelovic@protonmail.com>
* feat: add support for direct connections
* refactor: simplify a bit, change comments, extend tests
* fix: compiler warning about unused variable
* docs: add section on direct connections to the tutorial
---------
Co-authored-by: Maksim Fedyarov <m.fedyarov@omp.ru>
Co-authored-by: Stanislav Angelovič <stanislav.angelovic@protonmail.com>
* chore: don't use systemd headers with elogind
In file included from src/VTableUtils.c:27:
src/VTableUtils.h:30:10: fatal error: 'systemd/sd-bus.h' file not found
#include <systemd/sd-bus.h>
^~~~~~~~~~~~~~~~~~
* chore: add basu support
Similar to elogind but also supported on non-Linux.
* chore(tests): permit /var/lib/machine-id on non-systemd
https://github.com/elogind/elogind/commit/84fdc0fc61c1https://git.sr.ht/~emersion/basu/commit/8324e6729231
* chore(ci): add simple freebsd job
Mainly to cover libc++ and basu.
* chore(ci): explicitly pass CMAKE_INSTALL_PREFIX
Some sdbus-cpp tests require configuring system bus. However, Linux
testing relies on writing outside of prefix in order to affect current
system bus instance instead of launching a dedicated one.
* chore(tests): respect CMAKE_INSTALL_PREFIX for system bus config
DBus isn't part of base system on BSDs, so may not use /etc for configs.
Also, testing installation failed as non-root:
$ cmake -DBUILD_TESTS=1 -DCMAKE_INSTALL_PREFIX=/tmp/sdbus-cpp_prefix -DTESTS_INSTALL_PATH=/tmp/sdbus-cpp_prefix/tests
$ cmake --build .
$ cmake --install .
[...]
CMake Error at tests/cmake_install.cmake:105 (file):
file cannot create directory: /etc/dbus-1/system.d. Maybe need
administrative privileges.
* chore(tests): temporarily skip 1 test on FreeBSD to keep CI happy
* chore(ci): run tests in freebsd job
* feat: support serialization of array, span and unordered_map
* fix some spelling mistakes
* docs: update table of valid c++ types
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Co-authored-by: Marcel Hellwig <github@cookiesoft.de>
* Add methods to initiate custom session bus connection
The new function helper `createSessionBusConnectionWithAddress` allows to create connection to session bus with custom address.
Signed-off-by: Alexander Livenets <a.livenets@gmail.com>
* feat: add support for session bus connection at custom address
Co-authored-by: Stanislav Angelovic <stanislav.angelovic@siemens.com>
Stanislav Angelovič
Stanislav Angelovic
Stanislav Angelovic
Marcel Hellwig
David ReissandDavid Reiss
Jan Beich
Anthony Brandon
alivenetsandStanislav Angelovic