If sending a lot of data and/or the other peer is not reading it, then
socket buffers can overflow. This is communicated from the kernel by
returning EAGAIN. In GIO, it is modelled by g_output_stream_write()
and g_socket_send_message() returning G_IO_ERROR_WOULD_BLOCK.
It is also problematic that that we're using synchronous IO in the
shared GDBus IO thread. It means that one GDBusConnection can lock up
others.
It turns out that by porting from g_output_stream_write() to
g_output_stream_write_async() we fix the EAGAIN issue. For GSocket, we
still need to handle things manually (by creating a GSource) as
g_socket_send_message() is used.
We check the new behavior in Michael's producer/consumer test case (at
/gdbus/overflow in gdbus-peer.c) added in the last commit.
Also add a test case that sends and receives a 20 MiB message.
Also add a new `transport' G_DBUS_DEBUG option so it is easy to
inspect partial writes:
$ G_DBUS_DEBUG=transport ./gdbus-connection -p /gdbus/connection/large_message
[...]
========================================================================
GDBus-debug:Transport:
>>>> WROTE 128000 bytes of message with serial 4 and
size 20971669 from offset 0 on a GSocketOutputStream
========================================================================
GDBus-debug:Transport:
>>>> WROTE 128000 bytes of message with serial 4 and
size 20971669 from offset 128000 on a GSocketOutputStream
========================================================================
GDBus-debug:Transport:
>>>> WROTE 128000 bytes of message with serial 4 and
size 20971669 from offset 256000 on a GSocketOutputStream
[...]
========================================================================
GDBus-debug:Transport:
>>>> WROTE 43669 bytes of message with serial 4 and
size 20971669 from offset 20928000 on a GSocketOutputStream
[...]
========================================================================
GDBus-debug:Transport:
<<<< READ 16 bytes of message with serial 3 and
size 20971620 to offset 0 from a GSocketInputStream
========================================================================
GDBus-debug:Transport:
<<<< READ 15984 bytes of message with serial 3 and
size 20971620 to offset 16 from a GSocketInputStream
========================================================================
GDBus-debug:Transport:
<<<< READ 16000 bytes of message with serial 3 and
size 20971620 to offset 16000 from a GSocketInputStream
[...]
========================================================================
GDBus-debug:Transport:
<<<< READ 144000 bytes of message with serial 3 and
size 20971620 to offset 20720000 from a GSocketInputStream
========================================================================
GDBus-debug:Transport:
<<<< READ 107620 bytes of message with serial 3 and
size 20971620 to offset 20864000 from a GSocketInputStream
OK
https://bugzilla.gnome.org/show_bug.cgi?id=626748
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>
Also add a 'address' G_DBUS_DEBUG option that will print out useful
debug information such as
GDBus-debug:Address: In g_dbus_address_get_for_bus_sync() for bus type `session'
GDBus-debug:Address: env var DBUS_SESSION_BUS_ADDRESS is not set
GDBus-debug:Address: env var DBUS_SYSTEM_BUS_ADDRESS is not set
GDBus-debug:Address: env var DBUS_STARTER_BUS_TYPE is not set
GDBus-debug:Address: Running `dbus-launch --autolaunch=05e508961149264c9b750a4c494aa6f7 --binary-syntax --close-stderr' to get bus address (possibly autolaunching)
GDBus-debug:Address: dbus-launch output:
0000: 75 6e 69 78 3a 61 62 73 74 72 61 63 74 3d 2f 74 unix:abstract=/t
0010: 6d 70 2f 64 62 75 73 2d 77 42 41 6f 4b 59 49 52 mp/dbus-wBAoKYIR
0020: 7a 75 2c 67 75 69 64 3d 30 34 30 64 31 33 66 33 zu,guid=040d13f3
0030: 30 61 30 62 35 32 63 32 30 66 36 32 63 34 31 63 0a0b52c20f62c41c
0040: 30 30 30 30 35 30 38 64 00 d2 38 00 00 01 00 40 0000508d..8....@
0050: 05 00 00 00 00 .....
GDBus-debug:Address: dbus-launch stderr output:
14542: Autolaunch enabled (using X11).
14542: --exit-with-session automatically enabled
14542: Connected to X11 display ':0.0'
14542: === Parent dbus-launch continues
14542: Waiting for babysitter's intermediate parent
14542: Reading address from bus
14542: Reading PID from daemon
14542: Saving x11 address
14542: Created window 88080385
14542: session file: /root/.dbus/session-bus/05e508961149264c9b750a4c494aa6f7-0
14542: dbus-launch exiting
GDBus-debug:Address: Returning address `unix:abstract=/tmp/dbus-wBAoKYIRzu,guid=040d13f30a0b52c20f62c41c0000508d' for bus type `session'
and
GDBus-debug:Address: In g_dbus_address_get_for_bus_sync() for bus type `session'
GDBus-debug:Address: env var DBUS_SESSION_BUS_ADDRESS is not set
GDBus-debug:Address: env var DBUS_SYSTEM_BUS_ADDRESS is not set
GDBus-debug:Address: env var DBUS_STARTER_BUS_TYPE is not set
GDBus-debug:Address: Running `dbus-launch --autolaunch=05e508961149264c9b750a4c494aa6f7 --binary-syntax --close-stderr' to get bus address (possibly autolaunching)
GDBus-debug:Address: dbus-launch output:
0000: 75 6e 69 78 3a 61 62 73 74 72 61 63 74 3d 2f 74 unix:abstract=/t
0010: 6d 70 2f 64 62 75 73 2d 77 42 41 6f 4b 59 49 52 mp/dbus-wBAoKYIR
0020: 7a 75 2c 67 75 69 64 3d 30 34 30 64 31 33 66 33 zu,guid=040d13f3
0030: 30 61 30 62 35 32 63 32 30 66 36 32 63 34 31 63 0a0b52c20f62c41c
0040: 30 30 30 30 35 30 38 64 00 d2 38 00 00 01 00 40 0000508d..8....@
0050: 05 00 00 00 00 .....
GDBus-debug:Address: dbus-launch stderr output:
14549: Autolaunch enabled (using X11).
14549: --exit-with-session automatically enabled
14549: Connected to X11 display ':0.0'
14549: dbus-daemon is already running. Returning existing parameters.
14549: dbus-launch exiting
GDBus-debug:Address: Returning address `unix:abstract=/tmp/dbus-wBAoKYIRzu,guid=040d13f30a0b52c20f62c41c0000508d' for bus type `session'
Note that things work exactly like libdbus, e.g. from the
dbus-launch(1) man page:
Whenever an autolaunch occurs, the application that had to start a
new bus will be in its own little world; it can effectively end up
starting a whole new session if it tries to use a lot of bus
services. This can be suboptimal or even totally broken, depending
on the app and what it tries to do.
[...]
You can always avoid autolaunch by manually setting
DBUS_SESSION_BUS_ADDRESS. Autolaunch happens because the default
address if none is set is "autolaunch:", so if any other address is
set there will be no autolaunch. You can however include autolaunch
in an explicit session bus address as a fallback, for example
DBUS_SESSION_BUS_ADDRESS="something:,autolaunch:" - in that case if
the first address doesn't work, processes will autolaunch. (The bus
address variable contains a comma-separated list of addresses to
try.)
Signed-off-by: David Zeuthen <davidz@redhat.com>
This commit adds the following G_DBUS_DEBUG flags
- emission
- incoming
- call
- signal
- payload
https://bugzilla.gnome.org/show_bug.cgi?id=620913
Signed-off-by: David Zeuthen <davidz@redhat.com>
2007-12-19 Alexander Larsson <alexl@redhat.com>
* gio/migrating.xml:
* gio/overview.xml:
Some minor fixes and additions.
svn path=/trunk/; revision=6154
2007-12-17 Matthias Clasen <mclasen@redhat.com>
* gio/migration.xml: Stub of a migration chapter
* gio/overview.xml: Stub of an overview
* gio/gvfs-overview.{odg,png}: Overview diagram taken
from Alex Guadec slides.
* gio/Makefile.am:
* gio/gio-docs.xml: Include these
svn path=/trunk/; revision=6145
