Re: [PATCH v6 03/12] hmp: Set cur_mon only in handle_hmp_command()

[Markus Armbruster]

Kevin Wolf <kwolf@redhat.com> writes:

> cur_mon is updated relatively early in the command handling code even

@cur_mon doesn't exist anymore (you renamed it to @cur_monitor in the
previous patch).  Either say "The current monitor", or use the actual
variable name.

> though only the command handler actually needs it. Move it to
> handle_hmp_command().

The commit message explains why moving it isn't wrong.  Can you also
explain why you want to move it?

>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  monitor/hmp.c  | 23 ++++++++++++-----------
>  monitor/misc.c |  7 -------
>  2 files changed, 12 insertions(+), 18 deletions(-)
>
> diff --git a/monitor/hmp.c b/monitor/hmp.c
> index f609fcf75b..79be6f26de 100644
> --- a/monitor/hmp.c
> +++ b/monitor/hmp.c
> @@ -1061,6 +1061,7 @@ void handle_hmp_command(MonitorHMP *mon, const char 
> *cmdline)
>      QDict *qdict;
>      const HMPCommand *cmd;
>      const char *cmd_start = cmdline;
> +    Monitor *old_mon;
>  
>      trace_handle_hmp_command(mon, cmdline);
>  
> @@ -1079,7 +1080,12 @@ void handle_hmp_command(MonitorHMP *mon, const char 
> *cmdline)
>          return;
>      }
>  
> +    /* old_mon is non-NULL when called from qmp_human_monitor_command() */
> +    old_mon = monitor_cur();
> +    monitor_set_cur(&mon->common);
>      cmd->cmd(&mon->common, qdict);
> +    monitor_set_cur(old_mon);
> +
>      qobject_unref(qdict);
>  }
>  
> @@ -1300,26 +1306,21 @@ cleanup:
>  
>  static void monitor_read(void *opaque, const uint8_t *buf, int size)
>  {
> -    MonitorHMP *mon;
> -    Monitor *old_mon = monitor_cur();
> +    Monitor *mon = opaque;
> +    MonitorHMP *hmp_mon = container_of(mon, MonitorHMP, common);
>      int i;
>  
> -    monitor_set_cur(opaque);
> -    mon = container_of(monitor_cur(), MonitorHMP, common);
> -
> -    if (mon->rs) {
> +    if (hmp_mon->rs) {
>          for (i = 0; i < size; i++) {
> -            readline_handle_byte(mon->rs, buf[i]);
> +            readline_handle_byte(hmp_mon->rs, buf[i]);
>          }
>      } else {
>          if (size == 0 || buf[size - 1] != 0) {
> -            monitor_printf(&mon->common, "corrupted command\n");
> +            monitor_printf(mon, "corrupted command\n");
>          } else {
> -            handle_hmp_command(mon, (char *)buf);
> +            handle_hmp_command(hmp_mon, (char *)buf);
>          }
>      }
> -
> -    monitor_set_cur(old_mon);
>  }

This does a bit more than just move monitor_set_cur().  Okay.

>  
>  static void monitor_event(void *opaque, QEMUChrEvent event)
> diff --git a/monitor/misc.c b/monitor/misc.c
> index 6cf7f60872..e0ab265726 100644
> --- a/monitor/misc.c
> +++ b/monitor/misc.c
> @@ -121,18 +121,13 @@ char *qmp_human_monitor_command(const char 
> *command_line, bool has_cpu_index,
>                                  int64_t cpu_index, Error **errp)
>  {
>      char *output = NULL;
> -    Monitor *old_mon;
>      MonitorHMP hmp = {};
>  
>      monitor_data_init(&hmp.common, false, true, false);
>  
> -    old_mon = monitor_cur();
> -    monitor_set_cur(&hmp.common);
> -
>      if (has_cpu_index) {
>          int ret = monitor_set_cpu(&hmp.common, cpu_index);
>          if (ret < 0) {
> -            monitor_set_cur(old_mon);
>              error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cpu-index",
>                         "a CPU number");
>              goto out;
> @@ -140,7 +135,6 @@ char *qmp_human_monitor_command(const char *command_line, 
> bool has_cpu_index,
>      }
>  
>      handle_hmp_command(&hmp, command_line);
> -    monitor_set_cur(old_mon);
>  
>      qemu_mutex_lock(&hmp.common.mon_lock);
>      if (qstring_get_length(hmp.common.outbuf) > 0) {
> @@ -258,7 +252,6 @@ static void monitor_init_qmp_commands(void)
>  /* Set the current CPU defined by the user. Callers must hold BQL. */
>  int monitor_set_cpu(Monitor *mon, int cpu_index)
>  {
> -    Monitor *cur_mon = monitor_cur();
>      CPUState *cpu;
>  
>      cpu = qemu_get_cpu(cpu_index);