Commit dc7cbcd8 authored by Peter Xu's avatar Peter Xu Committed by Markus Armbruster
Browse files

monitor: rename out_lock to mon_lock 



The out_lock is protecting a few Monitor fields.  In the future the
monitor code will start to run in multiple threads.  We are going to
turn it into a bigger lock to protect not only the out buffer but also
most of the rest.

Since at it, rearrange the Monitor struct a bit.

Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: default avatarMarkus Armbruster <armbru@redhat.com>
Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Message-Id: <20180608035511.7439-2-peterx@redhat.com>
Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
parent 2ef2f167

monitor.c

+29 −24
Original line number Diff line number Diff line
@@ -206,15 +206,6 @@ struct Monitor { 
    int suspend_cnt;            /* Needs to be accessed atomically */

    bool skip_flush;

    bool use_io_thr;



    /* We can't access guest memory when holding the lock */

    QemuMutex out_lock;

    QString *outbuf;

    guint out_watch;



    /* Read under either BQL or out_lock, written with BQL+out_lock.  */

    int mux_out;



    ReadLineState *rs;

    MonitorQMP qmp;

    gchar *mon_cpu_path;
@@ -223,6 +214,20 @@ struct Monitor { 
    mon_cmd_t *cmd_table;

    QLIST_HEAD(,mon_fd_t) fds;

    QTAILQ_ENTRY(Monitor) entry;



    /*

     * The per-monitor lock. We can't access guest memory when holding

     * the lock.

     */

    QemuMutex mon_lock;



    /*

     * Fields that are protected by the per-monitor lock.

     */

    QString *outbuf;

    guint out_watch;

    /* Read under either BQL or mon_lock, written with BQL+mon_lock.  */

    int mux_out;

};



/* Let's add monitor global variables to this struct. */
@@ -365,14 +370,14 @@ static gboolean monitor_unblocked(GIOChannel *chan, GIOCondition cond, 
{

    Monitor *mon = opaque;



    qemu_mutex_lock(&mon->out_lock);

    qemu_mutex_lock(&mon->mon_lock);

    mon->out_watch = 0;

    monitor_flush_locked(mon);

    qemu_mutex_unlock(&mon->out_lock);

    qemu_mutex_unlock(&mon->mon_lock);

    return FALSE;

}



/* Called with mon->out_lock held.  */

/* Called with mon->mon_lock held.  */

static void monitor_flush_locked(Monitor *mon)

{

    int rc;
@@ -410,9 +415,9 @@ static void monitor_flush_locked(Monitor *mon) 


void monitor_flush(Monitor *mon)

{

    qemu_mutex_lock(&mon->out_lock);

    qemu_mutex_lock(&mon->mon_lock);

    monitor_flush_locked(mon);

    qemu_mutex_unlock(&mon->out_lock);

    qemu_mutex_unlock(&mon->mon_lock);

}



/* flush at every end of line */
@@ -420,7 +425,7 @@ static void monitor_puts(Monitor *mon, const char *str) 
{

    char c;



    qemu_mutex_lock(&mon->out_lock);

    qemu_mutex_lock(&mon->mon_lock);

    for(;;) {

        c = *str++;

        if (c == '\0')
@@ -433,7 +438,7 @@ static void monitor_puts(Monitor *mon, const char *str) 
            monitor_flush_locked(mon);

        }

    }

    qemu_mutex_unlock(&mon->out_lock);

    qemu_mutex_unlock(&mon->mon_lock);

}



void monitor_vprintf(Monitor *mon, const char *fmt, va_list ap)
@@ -724,7 +729,7 @@ static void monitor_data_init(Monitor *mon, bool skip_flush, 
                              bool use_io_thr)

{

    memset(mon, 0, sizeof(Monitor));

    qemu_mutex_init(&mon->out_lock);

    qemu_mutex_init(&mon->mon_lock);

    qemu_mutex_init(&mon->qmp.qmp_queue_lock);

    mon->outbuf = qstring_new();

    /* Use *mon_cmds by default. */
@@ -744,7 +749,7 @@ static void monitor_data_destroy(Monitor *mon) 
    }

    readline_free(mon->rs);

    qobject_unref(mon->outbuf);

    qemu_mutex_destroy(&mon->out_lock);

    qemu_mutex_destroy(&mon->mon_lock);

    qemu_mutex_destroy(&mon->qmp.qmp_queue_lock);

    monitor_qmp_cleanup_req_queue_locked(mon);

    monitor_qmp_cleanup_resp_queue_locked(mon);
@@ -776,13 +781,13 @@ char *qmp_human_monitor_command(const char *command_line, bool has_cpu_index, 
    handle_hmp_command(&hmp, command_line);

    cur_mon = old_mon;



    qemu_mutex_lock(&hmp.out_lock);

    qemu_mutex_lock(&hmp.mon_lock);

    if (qstring_get_length(hmp.outbuf) > 0) {

        output = g_strdup(qstring_get_str(hmp.outbuf));

    } else {

        output = g_strdup("");

    }

    qemu_mutex_unlock(&hmp.out_lock);

    qemu_mutex_unlock(&hmp.mon_lock);



out:

    monitor_data_destroy(&hmp);
@@ -4381,9 +4386,9 @@ static void monitor_event(void *opaque, int event) 


    switch (event) {

    case CHR_EVENT_MUX_IN:

        qemu_mutex_lock(&mon->out_lock);

        qemu_mutex_lock(&mon->mon_lock);

        mon->mux_out = 0;

        qemu_mutex_unlock(&mon->out_lock);

        qemu_mutex_unlock(&mon->mon_lock);

        if (mon->reset_seen) {

            readline_restart(mon->rs);

            monitor_resume(mon);
@@ -4403,9 +4408,9 @@ static void monitor_event(void *opaque, int event) 
        } else {

            atomic_inc(&mon->suspend_cnt);

        }

        qemu_mutex_lock(&mon->out_lock);

        qemu_mutex_lock(&mon->mon_lock);

        mon->mux_out = 1;

        qemu_mutex_unlock(&mon->out_lock);

        qemu_mutex_unlock(&mon->mon_lock);

        break;



    case CHR_EVENT_OPENED: