On Thu, May 17, 2018 at 02:46:36PM +0200, Markus Armbruster wrote:
> Peter Xu <[email protected]> writes:
>
> > Add some explicit comment for both Readline and cpu_set/cpu_get helpers
> > that they do not need the mon_lock protection.
>
> Appreciated!
>
> > Signed-off-by: Peter Xu <[email protected]>
> > ---
> > monitor.c | 5 +++--
> > 1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/monitor.c b/monitor.c
> > index d6c3c08932..ae5bca9d7c 100644
> > --- a/monitor.c
> > +++ b/monitor.c
> > @@ -207,7 +207,7 @@ struct Monitor {
> > int suspend_cnt; /* Needs to be accessed atomically */
> > bool skip_flush;
> > bool use_io_thr;
> > - ReadLineState *rs;
> > + ReadLineState *rs; /* Only used in parser, so no lock needed. */
>
> Pardon the ignorant question: why does "only used in parser" imply "no
> lock needed"?
Since even if the monitors can be run in multiple threads now, the
monitor parser of a specific Monitor will still only be run in either
the main thread or the monitor iothread. My fault to be unclear on
the comment. Maybe this one is better:
It is only used in parser, and the parser of a monitor will only be
run either in main thread or monitor IOThread but never both, so no
lock is needed when accessing ReadLineState.
>
> > MonitorQMP qmp;
> > gchar *mon_cpu_path;
> > BlockCompletionFunc *password_completion_cb;
> > @@ -1313,7 +1313,7 @@ void qmp_qmp_capabilities(bool has_enable,
> > QMPCapabilityList *enable,
> > cur_mon->qmp.commands = &qmp_commands;
> > }
> >
> > -/* set the current CPU defined by the user */
> > +/* set the current CPU defined by the user. BQL needed. */
>
> It's okay to start a comment containing a phrase with a lower case
> letter, but you're turning this one into two sentences, and sentences
> start in upper case. Can touch up on commit.
>
> "BQL needed" is okay, just a bit terse; I'd write "Caller must hold
> BQL". Could change that, too.
I'll do that.
>
> > int monitor_set_cpu(int cpu_index)
> > {
> > CPUState *cpu;
> > @@ -1327,6 +1327,7 @@ int monitor_set_cpu(int cpu_index)
> > return 0;
> > }
> >
> > +/* BQL neeeded. */
>
> Likewise.
Will do. Thanks,
--
Peter Xu
