diff options
Diffstat (limited to 'monitor')
| -rw-r--r-- | monitor/qmp.c | 36 |
1 files changed, 31 insertions, 5 deletions
diff --git a/monitor/qmp.c b/monitor/qmp.c index 9d9e5d8b27..b67a8e7d1f 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -75,10 +75,35 @@ static void monitor_qmp_cleanup_req_queue_locked(MonitorQMP *mon) } } -static void monitor_qmp_cleanup_queues(MonitorQMP *mon) +static void monitor_qmp_cleanup_queue_and_resume(MonitorQMP *mon) { qemu_mutex_lock(&mon->qmp_queue_lock); + + /* + * Same condition as in monitor_qmp_bh_dispatcher(), but before + * removing an element from the queue (hence no `- 1`). + * Also, the queue should not be empty either, otherwise the + * monitor hasn't been suspended yet (or was already resumed). + */ + bool need_resume = (!qmp_oob_enabled(mon) || + mon->qmp_requests->length == QMP_REQ_QUEUE_LEN_MAX) + && !g_queue_is_empty(mon->qmp_requests); + monitor_qmp_cleanup_req_queue_locked(mon); + + if (need_resume) { + /* + * handle_qmp_command() suspended the monitor because the + * request queue filled up, to be resumed when the queue has + * space again. We just emptied it; resume the monitor. + * + * Without this, the monitor would remain suspended forever + * when we get here while the monitor is suspended. An + * unfortunately timed CHR_EVENT_CLOSED can do the trick. + */ + monitor_resume(&mon->common); + } + qemu_mutex_unlock(&mon->qmp_queue_lock); } @@ -263,9 +288,10 @@ static void handle_qmp_command(void *opaque, QObject *req, Error *err) /* * Suspend the monitor when we can't queue more requests after - * this one. Dequeuing in monitor_qmp_bh_dispatcher() will resume - * it. Note that when OOB is disabled, we queue at most one - * command, for backward compatibility. + * this one. Dequeuing in monitor_qmp_bh_dispatcher() or + * monitor_qmp_cleanup_queue_and_resume() will resume it. + * Note that when OOB is disabled, we queue at most one command, + * for backward compatibility. */ if (!qmp_oob_enabled(mon) || mon->qmp_requests->length == QMP_REQ_QUEUE_LEN_MAX - 1) { @@ -332,7 +358,7 @@ static void monitor_qmp_event(void *opaque, int event) * stdio, it's possible that stdout is still open when stdin * is closed. */ - monitor_qmp_cleanup_queues(mon); + monitor_qmp_cleanup_queue_and_resume(mon); json_message_parser_destroy(&mon->parser); json_message_parser_init(&mon->parser, handle_qmp_command, mon, NULL); |