Chardev backends may not handle safely IO events from concurrent
threads (they are not thread-safe in general, only the write path is
since commit > 9005b2a7589540a3733b3abdcfbccfe7746cd1a1). Better to
wake up the chardev from the monitor IO thread if it's being used as
the chardev context.
Unify code paths by using a BH in all cases.
Drop the now redundant aio_notify() call.
Simplify the condition, based on mon->use_io_thread (only QMP so far).
Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
Reviewed-by: Peter Xu <pet...@redhat.com>
---
monitor.c | 29 +++++++++++++++++++----------
1 file changed, 19 insertions(+), 10 deletions(-)
diff --git a/monitor.c b/monitor.c
index d531e8ccc9..79afe99079 100644
--- a/monitor.c
+++ b/monitor.c
@@ -4297,7 +4297,7 @@ int monitor_suspend(Monitor *mon)
atomic_inc(&mon->suspend_cnt);
- if (monitor_is_qmp(mon) && mon->use_io_thread) {
+ if (mon->use_io_thread) {
/*
* Kick I/O thread to make sure this takes effect. It'll be
* evaluated again in prepare() of the watch object.
@@ -4309,6 +4309,13 @@ int monitor_suspend(Monitor *mon)
return 0;
}
+static void monitor_accept_input(void *opaque)
+{
+ Monitor *mon = opaque;
+
+ qemu_chr_fe_accept_input(&mon->chr);
+}
+
void monitor_resume(Monitor *mon)
{
if (monitor_is_hmp_non_interactive(mon)) {
@@ -4316,20 +4323,22 @@ void monitor_resume(Monitor *mon)
}
if (atomic_dec_fetch(&mon->suspend_cnt) == 0) {
- if (monitor_is_qmp(mon)) {
- /*
- * For QMP monitors that are running in the I/O thread,
- * let's kick the thread in case it's sleeping.
- */
- if (mon->use_io_thread) {
- aio_notify(iothread_get_aio_context(mon_iothread));
- }
+ AioContext *ctx;
+
+ if (mon->use_io_thread) {
+ ctx = iothread_get_aio_context(mon_iothread);
} else {
+ ctx = qemu_get_aio_context();
+ }
+
+ if (!monitor_is_qmp(mon)) {
assert(mon->rs);
readline_show_prompt(mon->rs);
}
- qemu_chr_fe_accept_input(&mon->chr);
+
+ aio_bh_schedule_oneshot(ctx, monitor_accept_input, mon);
}
+
trace_monitor_suspend(mon, -1);
}
--
2.20.0.rc1
