Commit 6e5d4999 authored by Peter Maydell's avatar Peter Maydell
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Merge remote-tracking branch 'remotes/armbru/tags/pull-monitor-2019-11-19' into staging 



Monitor patches for 2019-11-19

# gpg: Signature made Tue 19 Nov 2019 08:50:57 GMT
# gpg:                using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg:                issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-monitor-2019-11-19:
  monitor/qmp: resume monitor when clearing its queue

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parents 385e43e6 2895aaa1

monitor/qmp.c

+31 −5
Original line number Diff line number Diff line
@@ -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);