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[Qemu-devel] [RFC v6 14/27] monitor: let suspend_cnt be thread safe
From: |
Peter Xu |
Subject: |
[Qemu-devel] [RFC v6 14/27] monitor: let suspend_cnt be thread safe |
Date: |
Tue, 19 Dec 2017 16:45:44 +0800 |
Monitor code now can be run in more than one thread. Let it be thread
safe when accessing suspend_cnt counter.
Signed-off-by: Peter Xu <address@hidden>
---
monitor.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/monitor.c b/monitor.c
index cf1e5d881c..844508d134 100644
--- a/monitor.c
+++ b/monitor.c
@@ -3862,7 +3862,7 @@ static int monitor_can_read(void *opaque)
{
Monitor *mon = opaque;
- return (mon->suspend_cnt == 0) ? 1 : 0;
+ return (atomic_mb_read(&mon->suspend_cnt) == 0) ? 1 : 0;
}
/*
@@ -3994,7 +3994,7 @@ int monitor_suspend(Monitor *mon)
{
if (!mon->rs)
return -ENOTTY;
- mon->suspend_cnt++;
+ atomic_inc(&mon->suspend_cnt);
return 0;
}
@@ -4002,8 +4002,9 @@ void monitor_resume(Monitor *mon)
{
if (!mon->rs)
return;
- if (--mon->suspend_cnt == 0)
+ if (atomic_dec_fetch(&mon->suspend_cnt) == 0) {
readline_show_prompt(mon->rs);
+ }
}
static QObject *get_qmp_greeting(Monitor *mon)
@@ -4068,19 +4069,19 @@ static void monitor_event(void *opaque, int event)
monitor_resume(mon);
monitor_flush(mon);
} else {
- mon->suspend_cnt = 0;
+ atomic_mb_set(&mon->suspend_cnt, 0);
}
break;
case CHR_EVENT_MUX_OUT:
if (mon->reset_seen) {
- if (mon->suspend_cnt == 0) {
+ if (atomic_mb_read(&mon->suspend_cnt) == 0) {
monitor_printf(mon, "\n");
}
monitor_flush(mon);
monitor_suspend(mon);
} else {
- mon->suspend_cnt++;
+ atomic_inc(&mon->suspend_cnt);
}
qemu_mutex_lock(&mon->out_lock);
mon->mux_out = 1;
--
2.14.3
- Re: [Qemu-devel] [RFC v6 09/27] monitor: create monitor dedicate iothread, (continued)
- [Qemu-devel] [RFC v6 10/27] monitor: allow to use IO thread for parsing, Peter Xu, 2017/12/19
- [Qemu-devel] [RFC v6 11/27] qmp: introduce QMPCapability, Peter Xu, 2017/12/19
- [Qemu-devel] [RFC v6 12/27] qmp: negotiate QMP capabilities, Peter Xu, 2017/12/19
- [Qemu-devel] [RFC v6 13/27] monitor: introduce monitor_qmp_respond(), Peter Xu, 2017/12/19
- [Qemu-devel] [RFC v6 14/27] monitor: let suspend_cnt be thread safe,
Peter Xu <=
- [Qemu-devel] [RFC v6 15/27] monitor: let suspend/resume work even with QMPs, Peter Xu, 2017/12/19
- [Qemu-devel] [RFC v6 16/27] monitor: separate QMP parser and dispatcher, Peter Xu, 2017/12/19
- [Qemu-devel] [RFC v6 17/27] qmp: add new event "command-dropped", Peter Xu, 2017/12/19
- [Qemu-devel] [RFC v6 18/27] monitor: send event when command queue full, Peter Xu, 2017/12/19