In _g_object_unref_and_wait_weak_notify() we take a weak reference and
then call g_object_unref() in an idle callback, which may look like
we're dropping a strong reference without having one. So change the
comment to make it more clear that the reference being dropped is held
by the caller.
Now that we're not calling g_object_run_dispose() indirectly in
g_test_dbus_down() (see commit "Revert "gtestdbus: Properly close server
connections""), the test gdbus-connection-loss is failing with the
message "Bail out! GLib-GIO-FATAL-WARNING: Weak notify timeout, object
ref_count=1". This is because we're holding a reference to the singleton
connection object while calling session_bus_down() in the test's main().
So then we end up waiting for 30 seconds in
_g_object_unref_and_wait_weak_notify() for the GWeakNotify to be
triggered, which never happens.
The fix is to unref the connection before calling session_bus_down().
This is consistent with how other tests work, and is safe because the
only method called on the connection has already errored out, as
asserted by the test.
This reverts commit c37cd19fee.
Now that we've reverted the commit "gtestdbus: Properly close server
connections", g_test_dbus_down() no longer returns early and we no
longer need this workaround. Since the gdbus-names test seems to
properly unref its GDBusConnection objects it's not clear to me why it
needed the sleep to succeed. However even at the time the failure wasn't
reproducible according to this comment[1] so it's probably not worth
spending more effort trying to reproduce it now.
[1] https://gitlab.gnome.org/GNOME/glib/issues/787#note_214235
This reverts commit baf92d09d6.
Closes#787
According to the original commit, this change was made because otherwise
g_test_dbus_down() following a g_test_dbus_stop() hangs until it times
out. The timeout being referred to is the 30 seconds which are waited by
_g_object_unref_and_wait_weak_notify() for the GWeakNotify to be
triggered when the last strong reference to the singleton
GDBusConnection object is dropped. But the patch was not correct and the
leak should have instead been fixed by having the last strong reference
holder drop their reference on the GDBusConnection before calling
g_test_dbus_down(). Timing out after 30 seconds is the desired behavior
in the case where someone holds a reference to the singleton for that
entire period.
There are a few problems with this patch. First, as pointed out here[1],
calling g_object_run_dispose() in the idle callback means we are causing
the GWeakNotify to trigger ~immediately rather than waiting 30 seconds
to give another owner a chance to unref. Second, since someone else may
still hold a reference on the object being disposed, they may call
methods on it after it's been disposed which can seg fault as documented
here[2] and as I also saw recently in another project.
It's unclear what the original leak being fixed was, but many have been
fixed between 2013 and now. I ran all the unit tests under valgrind, and
some do fail (some consistently and some intermittently) but none of the
failures seem to only happen after this reversion commit. I also
couldn't find anywhere in the valgrind output where any GDBusConnection
objects are definitely being lost.
[1] https://gitlab.gnome.org/GNOME/glib/issues/787#note_214226
[2] https://gitlab.gnome.org/GNOME/glib/issues/787#note_214237
This commit changes a comment in _g_dbus_worker_do_read_cb() to be
slightly more useful. At least in my experience debugging an
intermittent unit test failure in another project, this failure
condition occurred because although g_test_dbus_down() ensures that the
session GDBusConnection has exit-on-close set to FALSE before killing
its dbus-daemon, there was still a GDBusConnection on the system bus
which hit this failed read code path, because we had
DBUS_SYSTEM_BUS_ADDRESS set to the address of the #GTestDBus daemon, to
appease libudisks.
Also, make a few other minor improvements to the docs.
On Visual Studio, Meson builds modules as xxxx.dll, not libxxxx.dll when
xxxx is specified as the name for the shared_module() build directive.
This means that in the test programs if we expect for libxxxx for the
module name, the test will fail as there is no libxxxx.dll but there is
xxxx.dll. This makes the test program look for the module files
correctly.
This makes use of the string we now have from glib-private.h in the
last commit so that setlocale() sets the default system locale
correctly and therefore show the translated messages properly.
Fixes issue #1169.
Using the generic marshaller has drawbacks beyond performance. One such
drawback is that it breaks the stack unwinding from the Linux kernel due
to having unsufficient data to walk past ffi_call_unixt64. That means that
performance profiling by application developers looks grouped among
seemingly unrelated code paths.
While we can't fix the kernel unwinding here, we can provide proper
c_marshallers and va_marshallers for objects within Gio so that
performance profiling of applications is more reliable.
Related to GNOME/Initiatives#10
If c_marshaller is provided during g_signal_new() registration, the
automatic va_marshaller will not be set. If we leave the c_marshaller as
NULL in the simple cases, both a c_marshaller and va_marshaller will be
set for us.
This is particularly helpful when dealing with stack traces from Linux
perf, which often cannot unwind the stack beyond the ffi_call_unix64
stack-frame on x86_64.
Related to GNOME/Initiatives#10
This ensures that D-Bus connections established with unix:dir and
unix:path addresses actually work properly. Previously, we only tested
unix:tmpdir and TCP addresses.
This is not going to have much any effect currently since stop() just
disconnects a signal handler (that is going to be disconnected in
finalize anyway) and stops the socket service (that is going to be
destroyed in finalize), but it makes sense to do here for robustness.
unix:dir= addresses are exactly the same as unix:tmpdir= addresses,
already supported by GDBus, except they forbid use of abstract sockets.
This is convenient for situations where abstract sockets are
impermissible, such as when a D-Bus client inside a network namespace
needs to connect to a server running in a different network namespace.
An abstract socket cannot be shared between two processes in different
network namespaces.
Applications could use unix:path= addresses instead, so this is only a
convenience, but there's no good reason not to support unix:dir=.
Currently it is not supported simply because unix:dir= is a relatively
recent addition to the D-Bus spec.
It's somewhat unrealistic to use a GDBusServer without a
GDBusAuthObserver, because most D-Bus servers want to be like the
standard session bus (the owning user can connect) rather than being
like the standard system bus (all users can connect, the server is a
security boundary, and many bugs are security vulnerabilities).
Signed-off-by: Simon McVittie <smcv@collabora.com>
This is simpler and more robust than DBUS_COOKIE_SHA1, which relies
on assumptions about random numbers and a secure home directory.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Authentication is about proving who I am; authorization is about
whether, given the knowledge of who I am, I am allowed to do something.
GDBusServer and GDBusConnection carry out authentication automatically,
but rely on the library user to carry out authorization.
Signed-off-by: Simon McVittie <smcv@collabora.com>
This is useful information for implementors of portable software to know
whether they can rely on credentials-passing.
Signed-off-by: Simon McVittie <smcv@collabora.com>
