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[Qemu-devel] [PATCH 2.1 36/36] monitor: protect event emission
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH 2.1 36/36] monitor: protect event emission |
Date: |
Wed, 18 Jun 2014 08:44:00 +0200 |
Event emission must be protected by a mutex because of access to
the shared rate-limiting state, and to guard against concurrent
monitor "hot-plug" by means of human-monitor-command.
Reviewed-by: Luiz Capitulino <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
monitor.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/monitor.c b/monitor.c
index 2b97e4e..38a64a3 100644
--- a/monitor.c
+++ b/monitor.c
@@ -217,6 +217,9 @@ struct Monitor {
/* QMP checker flags */
#define QMP_ACCEPT_UNKNOWNS 1
+/* Protects mon_list, monitor_event_state. */
+static QemuMutex monitor_lock;
+
static QLIST_HEAD(mon_list, Monitor) mon_list;
static QLIST_HEAD(mon_fdsets, MonFdset) mon_fdsets;
static int mon_refcount;
@@ -465,6 +468,7 @@ static MonitorQAPIEventState
monitor_qapi_event_state[QAPI_EVENT_MAX];
/*
* Emits the event to every monitor instance, @event is only used for trace
+ * Called with monitor_lock held.
*/
static void monitor_qapi_event_emit(QAPIEvent event, QObject *data)
{
@@ -497,6 +501,7 @@ monitor_qapi_event_queue(QAPIEvent event, QDict *data,
Error **errp)
now);
/* Rate limit of 0 indicates no throttling */
+ qemu_mutex_lock(&monitor_lock);
if (!evstate->rate) {
monitor_qapi_event_emit(event, QOBJECT(data));
evstate->last = now;
@@ -521,6 +526,7 @@ monitor_qapi_event_queue(QAPIEvent event, QDict *data,
Error **errp)
evstate->last = now;
}
}
+ qemu_mutex_unlock(&monitor_lock);
}
/*
@@ -536,12 +542,14 @@ static void monitor_qapi_event_handler(void *opaque)
evstate->data,
evstate->last,
now);
+ qemu_mutex_lock(&monitor_lock);
if (evstate->data) {
monitor_qapi_event_emit(evstate->event, evstate->data);
qobject_decref(evstate->data);
evstate->data = NULL;
}
evstate->last = now;
+ qemu_mutex_unlock(&monitor_lock);
}
/*
@@ -5285,6 +5293,11 @@ static void monitor_readline_flush(void *opaque)
monitor_flush(opaque);
}
+static void __attribute__((constructor)) monitor_lock_init(void)
+{
+ qemu_mutex_init(&monitor_lock);
+}
+
void monitor_init(CharDriverState *chr, int flags)
{
static int is_first_init = 1;
@@ -5322,7 +5335,10 @@ void monitor_init(CharDriverState *chr, int flags)
monitor_event, mon);
}
+ qemu_mutex_lock(&monitor_lock);
QLIST_INSERT_HEAD(&mon_list, mon, entry);
+ qemu_mutex_unlock(&monitor_lock);
+
if (!default_mon || (flags & MONITOR_IS_DEFAULT))
default_mon = mon;
}
--
1.9.3
- Re: [Qemu-devel] [PATCH 2.1 30/36] qapi event: clean up, (continued)
[Qemu-devel] [PATCH 2.1 32/36] qemu-char: do not call chr_write directly, Paolo Bonzini, 2014/06/18
[Qemu-devel] [PATCH 2.1 33/36] qemu-char: move pty_chr_update_read_handler around, Paolo Bonzini, 2014/06/18
[Qemu-devel] [PATCH 2.1 35/36] monitor: protect outbuf and mux_out with mutex, Paolo Bonzini, 2014/06/18
[Qemu-devel] [PATCH 2.1 34/36] qemu-char: make writes thread-safe, Paolo Bonzini, 2014/06/18
[Qemu-devel] [PATCH 2.1 36/36] monitor: protect event emission,
Paolo Bonzini <=
Message not available
Re: [Qemu-devel] [PATCH 2.1 00/36] Pending monitor patches for 2.1, Luiz Capitulino, 2014/06/19
Re: [Qemu-devel] [PATCH 2.1 00/36] Pending monitor patches for 2.1, Eric Blake, 2014/06/20
Re: [Qemu-devel] [PATCH 2.1 00/36] Pending monitor patches for 2.1, Markus Armbruster, 2014/06/26