qemu/include/chardev
Artem Pisarenko 7a9657ef53 chardev: fix mess in OPENED/CLOSED events when muxed
When chardev is multiplexed (mux=on) there are a lot of cases where
CHR_EVENT_OPENED/CHR_EVENT_CLOSED events pairing (expected from
frontend side) is broken. There are either generation of multiple
repeated or extra CHR_EVENT_OPENED events, or CHR_EVENT_CLOSED just
isn't generated at all.
This is mostly because 'qemu_chr_fe_set_handlers()' function makes its
own (and often wrong) implicit decision on updated frontend state and
invokes 'fd_event' callback with 'CHR_EVENT_OPENED'. And even worse,
it doesn't do symmetric action in opposite direction, as someone may
expect (i.e. it doesn't invoke previously set 'fd_event' with
'CHR_EVENT_CLOSED'). Muxed chardev uses trick by calling this function
again to replace callback handlers with its own ones, but it doesn't
account for such side effect.
Fix that using extended version of this function with added argument
for disabling side effect and keep original function for compatibility
with lots of frontends already using this interface and being
"tolerant" to its side effects.
One more source of event duplication is just line of code in
char-mux.c, which does far more than comment above says (obvious fix).

Signed-off-by: Artem Pisarenko <artem.k.pisarenko@gmail.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <7dde6abbd21682857f8294644013173c0b9949b3.1541507990.git.artem.k.pisarenko@gmail.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2019-02-12 17:35:56 +01:00
..
char-fd.h char-fd: remove useless chr pointer 2017-08-01 17:27:33 +02:00
char-fe.h chardev: fix mess in OPENED/CLOSED events when muxed 2019-02-12 17:35:56 +01:00
char-io.h chardev: move headers to include/chardev 2017-06-02 11:33:52 +04:00
char-mux.h chardev: introduce chr_machine_done hook 2018-03-12 16:12:46 +01:00
char-parallel.h char: fix alias devices regression 2017-06-08 17:57:36 +04:00
char-serial.h char: fix alias devices regression 2017-06-08 17:57:36 +04:00
char-win-stdio.h chardev: move headers to include/chardev 2017-06-02 11:33:52 +04:00
char-win.h chardev: move headers to include/chardev 2017-06-02 11:33:52 +04:00
char.h char: add a QEMU_CHAR_FEATURE_GCONTEXT flag 2018-12-12 09:55:57 +01:00