[Qemu-devel] Re: [PATCH 05/15] monitor: Handle new and old style handlers

[Anthony Liguori <aliguori@us.ibm.com>]

Luiz Capitulino wrote:
> This commit changes monitor_handle_command() to support old style
> _and_ new style handlers.
>
> New style handlers are protocol independent, they return their
> data to the Monitor, which in turn decides how to print them
> (ie. user protocol vs. machine protocol).
>
> Converted handlers will use the 'user_print' member of 'mon_cmd_t'
> to define its user protocol function, which will be called to print
> data in the user protocol format.
>
> Handlers which don't have 'user_print' defined are not converted
> and are handled as usual.
>
> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
> ---
>  monitor.c |   32 ++++++++++++++++++++++++++------
>  1 files changed, 26 insertions(+), 6 deletions(-)
>
> diff --git a/monitor.c b/monitor.c
> index 9d4c168..c0ba5ee 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -211,6 +211,11 @@ static int monitor_fprintf(FILE *stream, const char *fmt, ...)
>      return 0;
>  }
>
> +static inline int monitor_handler_ported(const mon_cmd_t *cmd)
> +{
> +    return cmd->user_print != NULL;
> +}
> +
>  static int compare_cmd(const char *name, const char *list)
>  {
>      const char *p, *pstart;
> @@ -3053,17 +3058,32 @@ static void monitor_handle_command(Monitor *mon, const char *cmdline)
>      qdict = qdict_new();
>
>      cmd = monitor_parse_command(mon, cmdline, qdict);
> -    if (cmd) {
> -        void (*handler)(Monitor *mon, const QDict *qdict);
> +    if (!cmd)
> +        goto out;
> +
> +    qemu_errors_to_mon(mon);
>
> -        qemu_errors_to_mon(mon);
> +    if (monitor_handler_ported(cmd)) {
> +        QObject *data = NULL;
> +        void (*handler_new)(Monitor *mon, const QDict *params,
> +                            QObject **ret_data);
>   

Screams to be a typedef.

> -        handler = cmd->handler;
> -        handler(mon, qdict);
> +        handler_new = cmd->handler;
> +        handler_new(mon, qdict, &data);
>   

At this point, couldn't cmd->handler be a union so we had a bit more 
type safety?

-- 
Regards,

Anthony Liguori