rhbz#1004443
The methods that trigger waitings on the client pipe require that
the waiting will succeed in order to continue, or otherwise, that
all the living pipe items will be released (e.g., when
we must destroy a surface, we need that all its related pipe items will
be released). Shutdown of the socket will eventually trigger
red_channel_client_disconnect (*), which will empty the pipe. However,
if the blocking method failed, we need to empty the pipe synchronously.
It is not safe(**) to call red_channel_client_disconnect from ChannelCbs
, but all the blocking calls in red_worker are done from callbacks that
are triggered from the device.
To summarize, calling red_channel_client_disconnect instead of calling
red_channel_client_shutdown will immediately release all the pipe items that are
held by the channel client (by calling red_channel_client_pipe_clear).
If red_clear_surface_drawables_from_pipe timeouts,
red_channel_client_disconnect will make sure that the surface we wish to
release is not referenced by any pipe-item.
(*) After a shutdown of a socket, we expect that later, when
red_peer_handle_incoming is called, it will encounter a socket
error and will call the channel's on_error callback which calls
red_channel_client_disconnect.
(**) I believe it was not safe before commit 2d2121a170 (before adding ref
count to ChannelClient). However, I think it might still be unsafe, because
red_channel_client_disconnect sets rcc->stream to NULL, and rcc->stream
may be referred later inside a red_channel_client method unsafely. So instead
of checking if (stream != NULL) after calling callbacks, we try to avoid
calling red_channel_client_disconnect from callbacks.
(1) merge 'force' and 'wait_for_outgoing_item' to one parameter.
'wait_for_outgoing_item' is a derivative of 'force'.
(2) move the call to red_wait_outgoing_item to red_clear_surface_drawables_from_pipe
client/Makefile.am:199: warning: 'INCLUDES' is the old name for 'AM_CPPFLAGS' (or '*_CPPFLAGS')
server/tests/Makefile.am:3: warning: 'INCLUDES' is the old name for 'AM_CPPFLAGS' (or '*_CPPFLAGS')
After eb09c25c, red_parse_qxl.c still has some spice_error() which
will kill the server even though the code is trying to return an error
when the spice_error() is hit.
This commit replaces these occurrences with a spice_warning() which
will not kill spice-server.
bitmap_consistent should return true or false.
Currently it aborts instead of returning false, due to spice_error.
Replacing spice_error with spice_warning, provides information and returns
false, as expected.
This fixes Fedora bz#997932
rhbz#994175
When a client connection is closed surprisingly (i.e., without a FIN
segment), we cannot identify it by a socket error (which is the only
way by which we identified disconnections so far).
This patch allows a channel client to periodically check the state of
the connection and identify surprise disconnections.
For channels that don't run as part of the main loop, we use
spice_timer_queue, while for the other channels we use
qemu timers support. The callbacks for setting timers are supplied to
red_channel via SpiceCoreInterface, and their behavior should be
consistent. qemu timers are called only once per each call to
timer_start. This patch assigns the same behaviour to spice_timer_queue.
Three blocking functions, one was split to leave the display channel
specific referencing of the DrawablePipeItem being sent inside
red_worker, but the rest (most) of the timeout logic was moved to
red_channel, including the associated constants.
Moved functions:
red_channel_client_wait_pipe_item_sent
red_wait_outgoing_item
red_wait_all_sent
Introduces red_time.h & red_time.c for a small helper function dealing
with time.h
setting DRAW_ALL define doesn't produce correct rendering. Using
update_area instead of red_draw_qxl_drawable will work but it shouldn't
be required. This is not work I intend to do right now, so marking it
for anyone looking at this in the future.
150 seconds is way too long period for holding the guest driver and
waiting for a response for the client. This timeout was 15 seconds, but
when off-screen surfaces ware introduced it was arbitrarily multiplied by
10.
Other existing related bugs emphasize why it is important to decrease
the timeout:
(1) 994211 - the qxl driver waits for an async-io reponse for 60 seconds
and after that, it switches to sync-io mode. Not only that the
driver might use invalid data (since it didn't wait for the query to
complete), falling back to sync-io mode introduces other errors.
(2) 994175 - spice server sometimes doesn't recognize that the client
has disconnected.
(3) There might be cache inconsistency between the client and the server,
and then the display channel waits indefinitely for a cache item (e.g., bug
977998)
This patch changes the timeout to 30 seconds. I tested it under wifi +emulating 2.5Mbps network,
together with playing video on the guest and changing resolutions in a loop. The timeout didn't expired
during my tests.
This bug is related to rhbz#964136 (but from rhbz#964136 info it is still not
clear why the client wasn't responsive).
The snd channels has one reference as long as their socket is active.
The playback channel has an additional reference for each frame that is
currently filled by the sound device.
Once the channel is disconnected (the socket has been freed and the
first reference is released) snd_disconnect_channel shouldn't release
a reference again.
When the sequence of calls bellow occurs, the PlaybackChannel
is not released (snd_channel_put is not called for the
samples that refer to the channel).
spice_server_playback_get_buffer
snd_channel_disconnect
spice_server_playback_put_samples
When we want to disconnect the main channel from a callback, it is
safer to use red_channel_client_shutdown, instead of directly
destroying the client. It is also more consistent with how other
channels treat errors.
red_channel_client_shutdown will trigger socket error in the main channel.
Then, main_channel_client_on_disconnect will be called,
and eventually, main_dispatcher_client_disconnect.
I didn't replace calls to reds_disconnect/reds_client_disconnect in
places where those calls were safe && that might need immediate client
disconnection.
Fixes rhbz#918169
Some channels make direct calls to reds/main_channel routines. If
these routines try to read/write to the socket, and they get socket
error, main_channel_client_on_disconnect is called, and triggers
red_client_destroy. In order to prevent accessing expired references
to RedClient, RedChannelClient, or other objects (inside the original call, after
red_client_destroy has been called) I made the call to
red_client_destroy asynchronous with respect to main_channel_client_on_disconnect.
I added MAIN_DISPATCHER_CLIENT_DISCONNECT to main_dispatcher.
main_channel_client_on_disconnect pushes this msg to the dispatcher,
instead of calling directly to reds_client_disconnect.
The patch uses RedClient ref-count in order to handle a case where
reds_client_disconnect is called directly (e.g., when a new client connects while
another one is connected), while there is already CLIENT_DISCONNECT msg
pending in the main_dispatcher.
Examples:
(1) snd_worker.c
snd_disconnect_channel()
channel->cleanup() //snd_playback_cleanup
reds_enable_mm_timer()
.
.
main_channel_push_multi_media_time()...socket_error
.
.
red_client_destory()
.
.
snd_disconnect_channel()
channel->cleanup()
celt051_encoder_destroy()
celt051_encoder_destory() // double release
Note that this bug could have been solved by changing the order of
calls: e.g., channel->stream = NULL before calling cleanup, and
some other changes + reference counting. However, I found other
places in the code with similar problems, and I looked for a general
solution, at least till we redesign red_channel to handle reference
counting more consistently.
(2) inputs_channel.c
inputs_connect()
main_channel_client_push_notify()...socket_error
.
.
red_client_destory()
.
.
red_channel_client_create() // refers to client which is already destroyed
(3) reds.c
reds_handle_main_link()
main_channel_push_init() ...socket error
.
.
red_client_destory()
.
.
main_channel_client_start_net_test(mcc) // refers to mcc which is already destroyed
This can explain the assert in rhbz#964136, comment #1 (but not the hang that occurred before).
Fixes: leaks of pipe items & "red_client_destroy: assertion `rcc->send_data.size == 0'"
red_channel_disconnect clears the pipe. It is called only once. After,
it was called, not items should be added to the pipe.
An example of when this assert can occur:
on_new_cursor_channel (red_worker.c), pushes 2 pipe items.
When it pushes the first pipe item, if the client has disconnected,
it can hit a socket error, and then, red_channel_client_disconnect is called.
The second call to adding a pipe item, will add the item to
the pipe. red_channel_client_pipe_add_type also calls
red_channel_client_push, which will update the send_data.size.
Then, the push will also hit a socket error, but red_channel_client_disconnect
won't clear the pending pipe item again, since it was already called.
When red_client_destory is called, we hit assertion `rcc->send_data.size
== 0'.
Note that if a pipe item is added to the pipe after
red_channel_client_disconnect was called, but without pushing it,
we should hit "spice_assert(rcc->pipe_size == 0)".
The ioctl on sockets is actually named SIOCOUTQ though its value
is identical to TIOCOUTQ which is for terminals.
SIOCOUTQ is linux specific so we add a header check and ifdef based
on the presence of the header
This prevents bogus ioctls on non-Linux platforms
In this case, make syntax-check is wrong, and we actually do
need the cast.
A cast is needed when types are uint64_t <--> pointer
Using a local "ptr" variable makes both gcc and syntax-check happy.
