monitor: do not use mb_read/mb_set for suspend_cnt
Clean up monitor_event to just use monitor_suspend/monitor_resume,
using mon->mux_out to protect against incorrect nesting (especially
on startup).
The only remaining case of reading suspend_cnt is in the can_read
callback, which is just advisory and can use qatomic_read.
As an extra benefit, mux_out is now simply protected by mon_lock.
Also, moving the prompt to the beginning of the main loop removes
it from the output in some error cases where QEMU does not actually
start successfully. It is not a full fix and it would be nice to
also remove the monitor heading, but this is already a small (though
unintentional) improvement.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/monitor/monitor.c b/monitor/monitor.c
index 20e33e2..15f9753 100644
--- a/monitor/monitor.c
+++ b/monitor/monitor.c
@@ -569,10 +569,15 @@
{
Monitor *mon = opaque;
- if (!monitor_is_qmp(mon)) {
+ qemu_mutex_lock(&mon->mon_lock);
+ if (!monitor_is_qmp(mon) && mon->reset_seen) {
MonitorHMP *hmp_mon = container_of(mon, MonitorHMP, common);
assert(hmp_mon->rs);
+ readline_restart(hmp_mon->rs);
+ qemu_mutex_unlock(&mon->mon_lock);
readline_show_prompt(hmp_mon->rs);
+ } else {
+ qemu_mutex_unlock(&mon->mon_lock);
}
qemu_chr_fe_accept_input(&mon->chr);
@@ -603,7 +608,7 @@
{
Monitor *mon = opaque;
- return !qatomic_mb_read(&mon->suspend_cnt);
+ return !qatomic_read(&mon->suspend_cnt);
}
void monitor_list_append(Monitor *mon)
