Separate the code for validating a method call from the code for
actually scheduling it for dispatch.
This will allow property Get/Set/GetAll calls to be dispatched to the
method_call handler without duplicating a lot of code.
https://bugzilla.gnome.org/show_bug.cgi?id=698375
We presently do a lot of checks on property sets (signature check,
correct interface, property exists, etc.) from the worker thread before
dispatching the call to the user's thread. The typecheck, however, is
saved until just before calling the user's vfunc, in their thread.
My best guess is that this was done to save having to unpack the value
from the tuple twice (since we don't unpack it until we're just about
the call the user).
This patch moves the check to the same place as all of the other checks.
The purpose of this change is to allow for sharing this check with the
(soon-to-be-introduced) case of handing property sets from
method_call().
This change has a minor side effect: error messages generated by sending
invalid values to property sets are no longer guaranteed to be correctly
ordered with respect to the void returns from successful property sets.
They will instead be correctly ordered with respect to the other error
messages.
https://bugzilla.gnome.org/show_bug.cgi?id=698375
Back in the far-off twentieth century, it was normal on unix
workstations for U+0060 GRAVE ACCENT to be drawn as "‛" and for U+0027
APOSTROPHE to be drawn as "’". This led to the convention of using
them as poor-man's ‛smart quotes’ in ASCII-only text.
However, "'" is now universally drawn as a vertical line, and "`" at a
45-degree angle, making them an `odd couple' when used together.
Unfortunately, there are lots of very old strings in glib, and also
lots of new strings in which people have kept up the old tradition,
perhaps entirely unaware that it used to not look stupid.
Fix this by just using 'dumb quotes' everywhere.
https://bugzilla.gnome.org/show_bug.cgi?id=700746
g_dbus_connection_call_with_unix_fd_list_sync () and
g_dbus_connection_call_sync () should allow None for the
bus_name parameter.
https://bugzilla.gnome.org/show_bug.cgi?id=683771
Signed-off-by: Richard Hughes <richard@hughsie.com>
Now that we're using g_simple_async_result_set_check_cancellable() we
no longer need this terrible hack of carrying the GCancellable on the
GSimpleAsyncResult using qdata. See bug 672013 for more details.
https://bugzilla.gnome.org/show_bug.cgi?id=672013
Signed-off-by: David Zeuthen <davidz@redhat.com>
Call g_simple_async_result_set_check_cancellable() after all
GSimpleAsyncResult creation in order to take advantage of the new
reliable cancellation feature.
The guarantee of reliable cancellation fixes a bug in dbusmenu (which
was already assuming that cancellation was reliable). See this bug:
https://bugs.launchpad.net/ubuntu/+source/libdbusmenu/+bug/953562https://bugzilla.gnome.org/show_bug.cgi?id=672013
Signed-off-by: David Zeuthen <davidz@redhat.com>
g_bus_get_finish() and g_bus_get_sync() both document that the returned
object will usually have exit-on-close set to TRUE, but the property's
documentation specified that its default is FALSE. While that's
technically true from a GObject perspective, it's not accurate from the
API user's perspective.
https://bugzilla.gnome.org/show_bug.cgi?id=668163
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: David Zeuthen <zeuthen@gmail.com>
Previously, this would fail the assertion
"connection->initialization_error != NULL" after the label "out".
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=665067
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: David Zeuthen <davidz@redhat.com>
This happens to work at the moment (because GDBusWorker.frozen is a
gboolean and not just a 1-bit bitfield), but isn't right: the gboolean
ends up with values 0 or G_DBUS_CONNECTION_FLAGS_DELAY_MESSAGE_PROCESSING
(which is more than 1).
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=664558
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: David Zeuthen <davidz@redhat.com>
Strictly speaking, neither of the two uses that aren't under the lock
*needs* to be atomic, but it seems better to be obviously correct (and
we save another 4 bytes of struct).
One of these uses is in g_dbus_connection_is_closed(), any use of which
is inherently a race condition anyway.
The other is g_dbus_connection_flush_sync, which as far as I can tell
just needs a best-effort check, to not waste effort on a connection that
has been closed for a while (but I could be wrong).
I removed the check for the closed flag altogether in
g_dbus_connection_send_message_with_reply_unlocked, because it turns out
to be redundant with one in g_dbus_connection_send_message_unlocked,
which is called immediately after.
g_dbus_connection_close_sync held the lock to check the closed flag,
which is no longer needed.
As far as I can tell, the only reason why the lock is still desirable
when setting the closed flag is so that remove_match_rule can't fail
by racing with close notification from the worker thread - but
on_worker_closed needs to hold the lock anyway, to deal with other
data structures, so there's no point in trying to eliminate the
requirement to hold the lock.
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=661992
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: David Zeuthen <davidz@redhat.com>
Also, a few that don't need to be.
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=661992
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: David Zeuthen <davidz@redhat.com>
This isn't strictly necessary, because in every location where it's
checked, if the reading thread misses an update from another thread,
it's indistinguishable from the reading thread having been scheduled
before the writing thread, which is an unavoidable race condition that
callers need to cope with anyway. On the other hand, merging exit_on_close
into atomic_flags gives the least astonishing semantics to library users
and saves 4 bytes of struct, and if you're accessing exit-on-close often
enough for it to be a performance concern, you're probably doing it wrong.
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=661992
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: David Zeuthen <davidz@redhat.com>
The thread shared between all GDBusWorker instances was variously called
the "worker thread" or "message handler thread", which I mostly changed to
"the GDBusWorker thread" to avoid ambiguity.
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=661992
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: David Zeuthen <davidz@redhat.com>
The only exceptions are those of the trivial getters/setters that don't
already need the initialization check for its secondary role as a memory
barrier (this is consistent with GSocket, where trivial getters/setters
don't check):
* g_dbus_connection_set_exit_on_close
* g_dbus_connection_get_exit_on_close
* g_dbus_connection_is_closed
g_dbus_connection_set_exit_on_close needs to be safe for
use before initialization anyway, so it can be set at construct-time.
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=661689
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: David Zeuthen <davidz@redhat.com>
Also document which fields require such a check in order to have correct
threading semantics.
This usage doesn't matches the GInitable documentation, which suggests
use of a GError - but using an uninitialized GDBusConnection is
programming error, and not usefully recoverable. (The GInitable
documentation may have been a mistake - GNOME#662208.) Also, not all of
the places where we need it can raise a GError.
The check serves a dual purpose: it turns a non-deterministic crash into
a deterministic critical warning, and is also a memory barrier for
thread-safety. All of these functions dereference or return fields that
are meant to be protected by FLAG_INITIALIZED, so they could crash or
return an undefined value to their caller without this, if called from a
thread that isn't the one that called initable_init() (although I can't
think of any way to do that without encountering a memory barrier,
undefined behaviour, or a race condition that leads to undefined
behaviour if the non-initializing thread wins the race).
One exception is that initable_init() itself makes a synchronous call.
We deal with that by passing new internal flags up the call stack, to
reassure g_dbus_connection_send_message_unlocked() that it can go ahead.
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=661689
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=661992
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: David Zeuthen <davidz@redhat.com>
The comment implied that even failed initialization would set
is_initialized = TRUE, but this wasn't the case - failed initialization
would only set initialization_error, and it was necessary to check both.
It turns out the documented semantics are nicer than the implemented
semantics, since this lets us use atomic operations, which are also
memory barriers, to avoid needing separate memory barriers or locks
for initialization_error (and other members that are read-only after
construction).
I expect to need more than one atomically-accessed flag to fix thread
safety, so instead of a minimal implementation I've turned is_initialized
into a flags word.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=661689
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=661992
Reviewed-by: David Zeuthen <davidz@redhat.com>
If the connection to the bus is lost while a method call is ongoing,
the method call does not get cancelled. Instead it just sits around
until it times out.
This is visible here on XO laptops when stopping the display manager
during shutdown. imsettings starts sending a sync message to give up
its bus name (via g_bus_unown_name()), then systemd terminates the
session bus at approximately the same time. imsettings then hangs for
about 20 seconds before timing out the message.
http://lists.freedesktop.org/archives/dbus/2011-September/014717.html
imsettings behaviour could be improved as described in that thread,
but I think this is a glib bug. I've also come up with the attached
patch which fixes it.
Credits for the bug-fix goes to Daniel Drake <dsd@laptop.org>. The test
case was written by David Zeuthen <zeuthen@gmail.com>.
https://bugzilla.gnome.org/show_bug.cgi?id=660637
Signed-off-by: David Zeuthen <davidz@redhat.com>
Add g_main_context_ref_thread_default(), which always returns a
reffed GMainContext, rather than sometimes returning a (non-reffed)
GMainContext, and sometimes returning NULL. This simplifies the
bookkeeping in any code that needs to keep a reference to the
thread-default context for a while.
https://bugzilla.gnome.org/show_bug.cgi?id=660994
We can't safely close the output part of the I/O stream until any
pending write or flush has been completed. In the worst case, this could
lead to an assertion failure in the worker (when the close wins the
race) or not closing the stream at all (when the write wins the race).
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=651268
Bug-NB: NB#271520
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Signed-off-by: David Zeuthen <davidz@redhat.com>
Also add convenience _with_unix_fd_list variants to GDBusConnection,
GDBusProxy and GDBusMethodInvocation types to easily support this.
Signed-off-by: David Zeuthen <davidz@redhat.com>
This function implements the following logic:
if (g_variant_is_floating (value))
g_variant_ref_sink (value);
which is used for consuming the return value of callbacks that may or
may not return floating references.
This patch also replaces a few instances of the above code with the new
function (GSettings, GDBus) and lifts a long-standing restriction on the
use of floating values as the return value for signal handlers by
improving g_value_take_variant().
https://bugzilla.gnome.org/show_bug.cgi?id=627974
To help cross compilation, don't use glib-genmarshal in our
build. This is easy now that we have g_cclosure_marshal_generic().
In gobject/, add gmarshal.[ch] to git (making the existing entry
points stubs).
In gio/, simply switch to using g_cclosure_marshal_generic().
https://bugzilla.gnome.org/show_bug.cgi?id=652168
If g_bus_get_sync() fails in authentication (because e.g. the process
uid, doesn't match the expected in EXTERNAL), a secondary call to
g_bus_get_sync() would notice we aren't initialized, and try
to initialize.
The assertion here is just wrong; we now explicitly and clearly handle
both cases where we already have an error, or we already succeeded.
https://bugzilla.gnome.org/show_bug.cgi?id=635694
If specified, the signal subscription is setup client-side but the match
rule is not sent to the server. This allows the caller to manually
register more detailed match rules.
It doesn't really work right now because of a dbus-daemon(1) bug - see
the comment added in the TODO section of gdbusconnection.c. So revert
to old behavior. The downside is a lot of files in /tmp but right now
that's better than not being able to run tests in a loop.
Signed-off-by: David Zeuthen <davidz@redhat.com>
Without this fix, the ./gdbus-connection test case occasionally fails, see
https://bugzilla.gnome.org/show_bug.cgi?id=629945#c5
like this
/gdbus/connection/basic: OK
/gdbus/connection/life-cycle: **
ERROR:gdbus-connection.c:223:test_connection_life_cycle: assertion failed:
(!quit_mainloop_fired)
cleaning up bus with pid 21794
Aborted (core dumped)
because the callback didn't happen on the same thread as where we are
running the loop.
Signed-off-by: David Zeuthen <davidz@redhat.com>
Turns out that GDBusWorker will issue callbacks (in its own thread)
even after g_dbus_worker_stop() has been called. This would rarely
happen (and unreffing a connection is even rarer) so only saw this bug
occasionally when running the gdbus-connection test case in a loop.
Fix up this issue by maintaining a set of GDBusConnection objects that
are currently "alive" and do nothing in the callbacks if the passed
user_data pointer is not in this set.
Also attempted to fix up a race condition with
_g_object_wait_for_single_ref_do() and its use of GObject toggle
references - for now, just resort to busy waiting, thereby
sidestepping the toggle reference mess altogether.
Signed-off-by: David Zeuthen <davidz@redhat.com>
==7269== 144 bytes in 6 blocks are definitely lost in loss record 1,282 of 1,325
==7269== at 0x4005BDC: malloc (vg_replace_malloc.c:195)
==7269== by 0x4056B74: g_malloc (gmem.c:164)
==7269== by 0x406EDB6: g_slice_alloc (gslice.c:842)
==7269== by 0x406EDFB: g_slice_alloc0 (gslice.c:854)
==7269== by 0x413C627: g_type_create_instance (gtype.c:1867)
==7269== by 0x412276A: g_object_constructor (gobject.c:1480)
==7269== by 0x4121E5D: g_object_newv (gobject.c:1264)
==7269== by 0x4121BD3: g_object_new (gobject.c:1176)
==7269== by 0x417CFB9: g_credentials_new (gcredentials.c:156)
==7269== by 0x41D9DBC: g_unix_credentials_message_deserialize (gunixcredentialsmessage.c:149)
==7269== by 0x41C422C: g_socket_control_message_deserialize (gsocketcontrolmessage.c:198)
==7269== by 0x41BFCE3: g_socket_receive_message (gsocket.c:3289)
==7269== by 0x41D99CE: g_unix_connection_receive_credentials (gunixconnection.c:476)
==7269== by 0x41FA829: _g_dbus_auth_run_server (gdbusauth.c:987)
==7269== by 0x4205DDB: initable_init (gdbusconnection.c:2196)
Bug #629689.
Rework filter functions as per
https://bugzilla.gnome.org/show_bug.cgi?id=624546#c8
This commit breaks ABI. However, this ABI break affects only
applications using filter functions. The only known user of is dconf.
Signed-off-by: David Zeuthen <davidz@redhat.com>
Don't leak the ptr arrays in the map_sender_unique_name_to_signal_data_array
hash table.
==23440== 84 (20 direct, 64 indirect) bytes in 1 blocks are definitely lost in loss record 920 of 993
==23440== at 0x4005BDC: malloc (vg_replace_malloc.c:195)
==23440== by 0x4057094: g_malloc (gmem.c:134)
==23440== by 0x406F2D6: g_slice_alloc (gslice.c:836)
==23440== by 0x401D2D0: g_ptr_array_sized_new (garray.c:799)
==23440== by 0x401D2AC: g_ptr_array_new (garray.c:783)
==23440== by 0x420834A: g_dbus_connection_signal_subscribe (gdbusconnection.c:3084)
Bug #628436.
==31063== 98 (24 direct, 74 indirect) bytes in 1 blocks are definitely lost in loss record 946 of 1,136
==31063== at 0x4005BDC: malloc (vg_replace_malloc.c:195)
==31063== by 0x4057094: g_malloc (gmem.c:134)
==31063== by 0x406F2D6: g_slice_alloc (gslice.c:836)
==31063== by 0x4092383: g_variant_get_child_value (gvariant-core.c:847)
==31063== by 0x408BE9E: g_variant_get_variant (gvariant.c:709)
==31063== by 0x40903F5: g_variant_valist_get_nnp (gvariant.c:3767)
==31063== by 0x40907A9: g_variant_valist_get_leaf (gvariant.c:3884)
==31063== by 0x4090D10: g_variant_valist_get (gvariant.c:4065)
==31063== by 0x4090E59: g_variant_valist_get (gvariant.c:4100)
==31063== by 0x40911B6: g_variant_get_va (gvariant.c:4296)
==31063== by 0x40910BC: g_variant_get (gvariant.c:4248)
==31063== by 0x4208DAF: invoke_set_property_in_idle_cb (gdbusconnection.c:3676)
Bug #628346.
Turns out we are leaking non-floating GVariant instances returned by
get_property() functions.
Also avoid imprecise language such as "newly-allocated GVariant" as
this doesn't specify whether the variant can be floating or not.
Also see https://bugzilla.gnome.org/show_bug.cgi?id=627974 as it is
very related to this change.
Signed-off-by: David Zeuthen <davidz@redhat.com>
... that is, make it private. This makes sense because users are never
expected to create such objects themselves - only the GDBus core will
need this.
Signed-off-by: David Zeuthen <davidz@redhat.com>
Allow modifying a GDBusMessage in a filter function and also add tests
for this. This breaks API but leaves ABI (almost) intact - at least
dconf's GSettings backend (the only big user I know of) will keep
working.
https://bugzilla.gnome.org/show_bug.cgi?id=624546
Signed-off-by: David Zeuthen <davidz@redhat.com>
This prints all GDBusMethodInvocation API usage and is normally used
with the `incoming' option. Example:
# G_DBUS_DEBUG=incoming,return ./polkitd --replace
Entering main event loop
Connected to the system bus
Registering null backend at priority -10
[...]
Acquired the name org.freedesktop.PolicyKit1
[...]
========================================================================
GDBus-debug:Incoming:
<<<< METHOD INVOCATION org.freedesktop.PolicyKit1.Authority.RegisterAuthenticationAgent()
on object /org/freedesktop/PolicyKit1/Authority
invoked by name :1.26
serial 299
========================================================================
GDBus-debug:Return:
>>>> METHOD ERROR org.freedesktop.PolicyKit1.Error.Failed
message `Cannot determine session the caller is in'
in response to org.freedesktop.PolicyKit1.Authority.RegisterAuthenticationAgent()
on object /org/freedesktop/PolicyKit1/Authority
to name :1.26
reply-serial 299
[...]
========================================================================
GDBus-debug:Incoming:
<<<< METHOD INVOCATION org.freedesktop.PolicyKit1.Authority.RegisterAuthenticationAgent()
on object /org/freedesktop/PolicyKit1/Authority
invoked by name :1.2402
serial 25
========================================================================
GDBus-debug:Return:
>>>> METHOD RETURN
in response to org.freedesktop.PolicyKit1.Authority.RegisterAuthenticationAgent()
on object /org/freedesktop/PolicyKit1/Authority
to name :1.2402
reply-serial 25
Signed-off-by: David Zeuthen <davidz@redhat.com>
The D-Bus spec mentions exactly what header fields are required for
various message types. Add tests for this as well.
Also disallow empty interfaces for signals since the D-Bus spec says
this is Verboten already.
Signed-off-by: David Zeuthen <davidz@redhat.com>
Spell out "RECEIVED SIGNAL" instead of "SIGNAL" to emphasize this is
about receiving a signal, not emitting one (which is "SIGNAL
EMISSION"). Also make the "arrows" point in the "right" direction
("<<<<" vs ">>>>") - like this:
========================================================================
GDBus-debug:Signal:
<<<< RECEIVED SIGNAL org.freedesktop.DBus.NameOwnerChanged
on object /org/freedesktop/DBus
sent by name org.freedesktop.DBus
and
========================================================================
GDBus-debug:Incoming:
<<<< METHOD INVOCATION org.freedesktop.PolicyKit1.Authority.EnumerateTemporaryAuthorizations()
on object /org/freedesktop/PolicyKit1/Authority
invoked by name :1.2176
Signed-off-by: David Zeuthen <davidz@redhat.com>
This should make things easier to debug:
g_dbus_connection_real_closed: Remote peer vanished with error:
Underlying GIOStream returned 0 bytes on an async read
(g-io-error-quark, 0). Exiting.
Signed-off-by: David Zeuthen <davidz@redhat.com>
Don't do too much work in the finalizer - in particular, there's no
need to send RemoveMatch() messages to the bus daemon since we're
going to sever the connection and the bus will garbage collect
anyway. In this case it crashed the process.
Also add a test case that checks that the appropriate GDestroyNotify
callbacks are called when unreffing a connection with either 1)
exported objects; 2) signal subscriptions or 3) filter functions
.. yes, ideally apps would unregister such callbacks before giving up
their ref but that's not how things work :-)
Signed-off-by: David Zeuthen <davidz@redhat.com>
This is preferable to the current magical solution whereby the serial
is only rewritten if non-zero. In particular, it makes it easier to
send the same message on multiple connections without having to reset
the serial number.
Signed-off-by: David Zeuthen <davidz@redhat.com>
This is currently unused but might be useful in the future. For
example, it might be nice with a way to bypass the current queue of
outgoing messages - having a flag enumeration allows us to add a
G_DBUS_SEND_MESSAGE_FLAGS_BYPASS_QUEUE etc. etc.
This commit breaks ABI and API. Users of the (rarely used) API to send
messages will have to port to this new API.
Signed-off-by: David Zeuthen <davidz@redhat.com>
This is currently unused but will probably be useful in the
future. For example, we could have a _ARG0_IS_PATH to specify that
arg0 should be used for arg0path.
This commit breaks API and ABI. Users of
g_dbus_connection_signal_subscribe() will need to port to this new
version.
Signed-off-by: David Zeuthen <davidz@redhat.com>
If the subtree introspection function indicates that an interface exists
but then the dispatch function returns a NULL vtable for that interface,
issue a g_warning pointing programmers in the right direction.
Return a NULL terminated C array instead of a GPtrArray
Also, document that %NULL is a permitted return value and clarify its
meaning.
Finally, avoid calling the enumeration function during dispatch when the
G_DBUS_SUBTREE_FLAGS_DISPATCH_TO_UNENUMERATED_NODES flag was given.
... so it is async, cancelable and returns an error. Also provide a
synchronous version.
This is an API/ABI break but it is expected that only very few
applications use this API.
Signed-off-by: David Zeuthen <davidz@redhat.com>
E.g. move these C structures out of public header files and into their
respective C files. Also nuke padding since this is no longer needed.
This leaves only GDBusProxy as an extendable type.
Signed-off-by: David Zeuthen <davidz@redhat.com>
While this a dangerous thing to allow (collissions, reply_serial not
matching up etc.), the added flexibility makes this a good trade-off -
for example, with this feature, it's now a lot easier to build message
routers.
Signed-off-by: David Zeuthen <davidz@redhat.com>
