qemu/util
Marc-André Lureau 873df2cec1 win32: work around main-loop busy loop on socket/fd event
Commit 05e514b1d4 introduced an AIO
context optimization to avoid calling event_notifier_test_and_clear() on
ctx->notifier. On Windows, the same notifier is being used to wakeup the
wait on socket events (see commit
d3385eb448).

The ctx->notifier event is added to the gpoll sources in
aio_set_event_notifier(), aio_ctx_check() should clear the event
regardless of ctx->notified, since Windows sets the event by itself,
bypassing the aio->notified. This fixes qemu not clearing the event
resulting in a busy loop.

Paolo suggested to me on irc to call event_notifier_test_and_clear()
after select() >0 from aio-win32.c's aio_prepare. Unfortunately, not all
fds associated with ctx->notifiers are in AIO fd handlers set.
(qemu_set_nonblock() in util/oslib-win32.c calls qemu_fd_register()).

This is essentially a v2 of a patch that was sent earlier:
https://lists.gnu.org/archive/html/qemu-devel/2017-01/msg00420.html

that resurfaced when James investigated Spice performance issues on Windows:
https://gitlab.freedesktop.org/spice/spice/issues/36

In order to test that patch, I simply tried running test-char on
win32, and it hangs. Applying that patch solves it. QIO idle sources
are not dispatched. I haven't investigated much further, I suspect
source priorities and busy looping still come into play.

This version keeps the "notified" field, so event_notifier_poll()
should still work as expected.

Cc: James Le Cuirot <chewi@gentoo.org>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-04 18:49:18 +02:00
..
aio-posix.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
aio-wait.c block: Use a single global AioWait 2018-09-25 15:50:15 +02:00
aio-win32.c aio-posix: Fix concurrent aio_poll/set_fd_handler. 2019-01-14 14:09:41 +00:00
aiocb.c block: move AioContext, QEMUTimer, main-loop to libqemuutil 2017-02-21 11:14:07 +00:00
async.c win32: work around main-loop busy loop on socket/fd event 2019-10-04 18:49:18 +02:00
atomic64.c util: add atomic64 2018-10-02 18:47:55 +02:00
base64.c
bitmap.c bitmap: Add bitmap_copy_with_{src|dst}_offset() 2019-07-15 15:39:02 +02:00
bitops.c avoid TABs in files that only contain a few 2019-01-11 15:46:56 +01:00
buffer.c
bufferiszero.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
cacheinfo.c Fix cacheline detection on FreeBSD/powerpc. 2019-09-19 14:42:13 +02:00
compatfd.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
coroutine-sigaltstack.c coroutine-sigaltstack: use helper for allocating stack memory 2016-09-29 14:13:39 +02:00
coroutine-ucontext.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
coroutine-win32.c coroutine: add a macro for the coroutine stack size 2016-09-29 14:13:39 +02:00
crc32c.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
cutils.c cutils: remove one unnecessary pointer operation 2019-07-15 15:39:02 +02:00
drm.c util: promote qemu_egl_rendernode_open() to libqemuutil 2018-08-27 10:51:44 +02:00
envlist.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
error.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
event_notifier-posix.c Revert "qemu: add a cleanup callback function to EventNotifier" 2018-01-24 19:20:19 +02:00
event_notifier-win32.c Revert "qemu: add a cleanup callback function to EventNotifier" 2018-01-24 19:20:19 +02:00
fifo8.c Include migration/vmstate.h less 2019-08-16 13:31:52 +02:00
filemonitor-inotify.c filemon: fix watch IDs to avoid potential wraparound issues 2019-04-02 13:52:02 +01:00
filemonitor-stub.c filemon: fix watch IDs to avoid potential wraparound issues 2019-04-02 13:52:02 +01:00
getauxval.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
guest-random.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
hbitmap.c hbitmap: enable merging across granularities 2019-08-16 16:28:02 -04:00
hexdump.c
host-utils.c host-utils: Implement unsigned quadword left/right shift and unit tests 2017-01-31 10:10:14 +11:00
id.c qemu-common: Move qemu_isalnum() etc. to qemu/ctype.h 2019-06-11 20:22:09 +02:00
iov.c block/qcow2: implement .bdrv_co_pwritev(_compressed)_part 2019-08-27 14:58:42 +01:00
iova-tree.c util: remove redundant include of glib.h and add osdep.h 2018-06-29 12:22:28 +01:00
keyval.c qobject: Replace qobject_incref/QINCREF qobject_decref/QDECREF 2018-05-04 08:27:53 +02:00
lockcnt.c qemu-thread: optimize QemuLockCnt with futexes on Linux 2017-01-16 13:25:18 +00:00
log.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
main-loop.c util: merge main-loop.c and iohandler.c 2019-07-15 11:20:43 +02:00
Makefile.objs util: merge main-loop.c and iohandler.c 2019-07-15 11:20:43 +02:00
memfd.c linux-user: add memfd_create 2019-09-11 08:46:17 +02:00
mmap-alloc.c util/mmap-alloc: support MAP_SYNC in qemu_ram_mmap() 2019-04-25 14:17:36 -03:00
module.c module: return success on module load 2019-08-21 16:29:57 +02:00
notify.c xen / notify: introduce a new XenWatchList abstraction 2019-09-24 12:18:47 +01:00
osdep.c slirp: prefer c99 types over BSD kind 2019-02-07 15:49:08 +02:00
oslib-posix.c memory: fetch pmem size in get_file_size() 2019-09-16 12:32:21 +02:00
oslib-win32.c util: WSAEWOULDBLOCK on connect should map to EINPROGRESS 2019-10-04 18:49:18 +02:00
pagesize.c util: move qemu_real_host_page_size/mask to osdep.h 2017-10-10 09:45:00 -07:00
path.c util/path: Do not cache all filenames at startup 2019-06-24 22:19:30 +02:00
qdist.c qdist: return "(empty)" instead of NULL when printing an empty dist 2016-08-03 18:44:56 +02:00
qemu-config.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
qemu-coroutine-io.c coroutine: move entry argument to qemu_coroutine_create 2016-07-13 13:26:02 +02:00
qemu-coroutine-lock.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
qemu-coroutine-sleep.c qemu-coroutine-sleep: drop CoSleepCB 2019-01-24 10:05:16 +00:00
qemu-coroutine.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
qemu-error.c monitor error: Make printf()-like functions return a value 2019-04-18 22:18:59 +02:00
qemu-openpty.c
qemu-option.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
qemu-print.c qemu-print: New qemu_fprintf(), qemu_vfprintf() 2019-04-18 22:18:59 +02:00
qemu-progress.c progress: Show current progress on SIGINFO 2017-04-28 18:48:11 +02:00
qemu-sockets.c util/qemu-sockets: fix keep_alive handling in inet_connect_saddr 2019-09-25 08:15:44 -05:00
qemu-thread-common.h Clean up includes 2018-12-20 10:29:08 +01:00
qemu-thread-posix.c qemu-thread: Add qemu_cond_timedwait 2019-09-16 17:13:06 +02:00
qemu-thread-win32.c qemu-thread: Add qemu_cond_timedwait 2019-09-16 17:13:06 +02:00
qemu-timer-common.c
qemu-timer.c util/qemu-timer: refactor deadline calculation for external timers 2019-08-20 17:26:21 +02:00
qht.c qht: constify arguments to some internal functions 2018-09-26 08:55:54 -07:00
qsp.c qemu-thread: Add qemu_cond_timedwait 2019-09-16 17:13:06 +02:00
range.c Don't talk about the LGPL if the file is licensed under the GPL 2019-01-30 10:51:20 +01:00
rcu.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
readline.c qemu-common: Move qemu_isalnum() etc. to qemu/ctype.h 2019-06-11 20:22:09 +02:00
stats64.c util/stats64: Fix min/max comparisons 2017-11-15 09:34:51 +01:00
sys_membarrier.c sys_membarrier: fix up include directives 2018-04-05 14:37:38 +02:00
systemd.c qemu-ga: obey LISTEN_PID when using systemd socket activation 2017-03-19 11:12:12 +01:00
thread-pool.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
throttle.c throttle: Assert that bkt->max is valid in throttle_compute_wait() 2017-09-26 14:46:23 +02:00
timed-average.c
trace-events socket: Add backlog parameter to socket_listen 2019-09-03 23:24:42 +02:00
unicode.c json: Reject invalid UTF-8 sequences 2018-08-24 20:26:37 +02:00
uri.c cutils: Provide strchrnul 2018-06-29 12:32:10 +02:00
uuid.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
vfio-helpers.c Include qemu/queue.h slightly less 2019-08-16 13:31:52 +02:00