[Qemu-devel] Re: [PATCH 15/15] monitor: Convert do_info_cpus() to QObject

[Luiz Capitulino <lcapitulino@redhat.com>]

On Tue, 06 Oct 2009 20:46:53 -0500
Anthony Liguori <aliguori@us.ibm.com> wrote:

> Luiz Capitulino wrote:
> > Each CPU information is stored in a QDict and the returned
> > QObject is a QList of all CPUs.
> >
> > The QDict contains the following information:
> >
> > - "CPU": cpu index
> > - "current": "yes" or "no"
> > - "pc": current PC
> > - "halted": "yes" or "no"
> >
> > The user output in the Monitor should not change and the
> > future monitor protocol is expected to emit something like:
> >
> > [ { "CPU": 0, "current": "yes", "pc": 0x..., "halted": "no" },
> > { "CPU": 1, "current": "no",  "pc": 0x..., "halted": "yes" } ]
> >
> > which corresponds to the following user output:
> >
> > * CPU #0: pc=0x00000000fffffff0
> >   CPU #1: pc=0x00000000fffffff0 (halted)
> >
> > Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
> > ---
> >  monitor.c |   94 +++++++++++++++++++++++++++++++++++++++++++++++++++---------
> >  1 files changed, 80 insertions(+), 14 deletions(-)
> >
> > diff --git a/monitor.c b/monitor.c
> > index 0dcf478..1487b72 100644
> > --- a/monitor.c
> > +++ b/monitor.c
> > @@ -46,6 +46,7 @@
> >  #include "kvm.h"
> >  #include "acl.h"
> >  #include "qint.h"
> > +#include "qlist.h"
> >  #include "qdict.h"
> >  #include "qstring.h"
> >
> > @@ -410,33 +411,98 @@ static void do_info_registers(Monitor *mon)
> >  #endif
> >  }
> >
> > -static void do_info_cpus(Monitor *mon)
> > +static void print_cpu_iter(QObject *obj, void *opaque)
> > +{
> > +    QDict *cpu;
> > +    int active = ' ';
> > +    Monitor *mon = opaque;
> > +
> > +    assert(qobject_type(obj) == QTYPE_QDICT);
> > +    cpu = qobject_to_qdict(obj);
> > +
> > +    if (strcmp(qdict_get_str(cpu, "current"), "yes") == 0)
> > +        active = '*';
> > +
> > +    monitor_printf(mon, "%c CPU #%d: ", active, (int)qdict_get_int(cpu, "CPU"));
> > +
> > +#if defined(TARGET_I386)
> > +    monitor_printf(mon, "pc=0x" TARGET_FMT_lx,
> > +                   (target_ulong) qdict_get_int(cpu, "pc"));
> > +#elif defined(TARGET_PPC)
> > +    monitor_printf(mon, "nip=0x" TARGET_FMT_lx,
> > +                   (target_long) qdict_get_int(cpu, "nip"));
> > +#elif defined(TARGET_SPARC)
> > +    monitor_printf(mon, "pc=0x " TARGET_FMT_lx,
> > +                   (target_long) qdict_get_int(cpu, "pc"));
> > +    monitor_printf(mon, "npc=0x" TARGET_FMT_lx,
> > +                   (target_long) qdict_get_int(cpu, "npc"));
> > +#elif defined(TARGET_MIPS)
> > +    monitor_printf(mon, "PC=0x" TARGET_FMT_lx,
> > +                   (target_long) qdict_get_int(cpu, "PC"));
> > +#endif
> > +
> > +    if (strcmp(qdict_get_str(cpu, "halted"), "yes") == 0)
> > +        monitor_printf(mon, " (halted)");
> > +
> > +    monitor_printf(mon, "\n");
> > +}
> > +
> > +static void monitor_print_cpus(Monitor *mon, const QObject *data)
> > +{
> > +    QList *cpu_list;
> > +
> > +    assert(qobject_type(data) == QTYPE_QLIST);
> > +    cpu_list = qobject_to_qlist(data);
> > +    qlist_iter(cpu_list, print_cpu_iter, mon);
> > +}
> > +
> > +/**
> > + * do_info_cpus(): Show CPU information
> > + *
> > + * Return a QList with a QDict for each CPU.
> > + *
> > + * For example:
> > + *
> > + * [ { "CPU": 0, "current": "yes", "pc": 0x..., "halted": "no" },
> > + *   { "CPU": 1, "current": "no",  "pc": 0x..., "halted": "yes" } ]
> > + */
> > +static void do_info_cpus(Monitor *mon, QObject **ret_data)
> >  {
> >      CPUState *env;
> > +    QList *cpu_list;
> > +
> > +    cpu_list = qlist_new();
> >
> >      /* just to set the default cpu if not already done */
> >      mon_get_cpu();
> >
> >      for(env = first_cpu; env != NULL; env = env->next_cpu) {
> > +        const char *answer;
> > +        QDict *cpu = qdict_new();
> > +
> >          cpu_synchronize_state(env);
> > -        monitor_printf(mon, "%c CPU #%d:",
> > -                       (env == mon->mon_cpu) ? '*' : ' ',
> > -                       env->cpu_index);
> > +
> > +        qdict_put(cpu, "CPU", qint_from_int(env->cpu_index));
> >   
> 
> I'd almost think that a json parser that supported varadics would make 
> this much easier..

 In this specific case most values are conditionally inserted into the dict,
so I think it's easier to insert them separately.

 But I've a function called qobject_from_fmt() which allows one to
do something like:

QObject *obj = qobject_from_fmt("{ s: [ i, s ], s: i }", ... );

 I'm not sure I've implemented it correctly, but will submit as
part of the series that will use it.