Re: [Qemu-devel] [PATCH v2 09/11] monitor: Split out monitor/qmp.c

[Kevin Wolf <kwolf@redhat.com>]

Am 12.06.2019 um 15:11 hat Markus Armbruster geschrieben:
> Kevin Wolf <kwolf@redhat.com> writes:
> 
> > Move QMP infrastructure from monitor/misc.c to monitor/qmp.c. This is
> > code that can be shared for all targets, so compile it only once.
> 
> Less code compiled per target, yay!
> 
> > The amount of function and particularly extern variables in
> > monitor_int.h is probably a bit larger than it needs to be, but this way
> > no non-trivial code modifications are needed. The interfaces between QMP
> > and the monitor core can be cleaned up later.
> 
> That's okay.
> 
> I have to admit I naively expected the previous patch moved everything
> to the new header we need in a header for splitting up monitor/misc.c.
> How did you decide what to move to the header in which patch?

The previous patch moved only the Monitor{HMP,QMP} data structures and
their dependencies as I was sure these would be shared. Everything else
was added to address linker complaints as I was going. I'll clarify this
in the commit message of the previous patch.

> > Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > ---
> >  include/monitor/monitor.h |   1 +
> >  monitor/monitor_int.h     |  30 ++-
> >  monitor/misc.c            | 394 +------------------------------------
> >  monitor/qmp.c             | 404 ++++++++++++++++++++++++++++++++++++++
> >  Makefile.objs             |   1 +
> >  monitor/Makefile.objs     |   1 +
> >  monitor/trace-events      |   4 +-
> >  7 files changed, 448 insertions(+), 387 deletions(-)
> >  create mode 100644 monitor/qmp.c
> >
> > diff --git a/include/monitor/monitor.h b/include/monitor/monitor.h
> > index 1ba354f811..7bbab05320 100644
> > --- a/include/monitor/monitor.h
> > +++ b/include/monitor/monitor.h
> > @@ -21,6 +21,7 @@ bool monitor_cur_is_qmp(void);
> >  
> >  void monitor_init_globals(void);
> >  void monitor_init(Chardev *chr, int flags);
> > +void monitor_init_qmp(Chardev *chr, int flags);
> 
> Why does this one go to the non-internal header?

Most callers already know whether they want QMP or HMP, so they can just
directly create the right thing instead of going through the
monitor_init() wrapper.

If you prefer, I can move it to the internal header, though. It's not
called externally yet.

> >  void monitor_cleanup(void);
> >  
> >  int monitor_suspend(Monitor *mon);
> > diff --git a/monitor/monitor_int.h b/monitor/monitor_int.h
> > index 7122418955..4aabee54e1 100644
> > --- a/monitor/monitor_int.h
> > +++ b/monitor/monitor_int.h
> > @@ -30,10 +30,11 @@
> >  
> >  #include "qapi/qmp/qdict.h"
> >  #include "qapi/qmp/json-parser.h"
> > -#include "qapi/qapi-commands.h"
> > +#include "qapi/qmp/dispatch.h"
> 
> This part should be squashed into the previous patch.  You'll
> additionally need qapi/qapi-types-misc.h for QMP_CAPABILITY__MAX there,
> or keep monitor/monitor.h, even though you need it only here for
> MONITOR_USE_CONTROL.

Yes, already happened while addressing the comments you had for the
header.

> >  
> >  #include "qemu/readline.h"
> >  #include "chardev/char-fe.h"
> > +#include "sysemu/iothread.h"
> 
> Perhaps IOThread should be typedef'ed in qemu/typedefs.h.  I'm not
> asking you to do that.
> 
> >  
> >  /*
> >   * Supported types:
> > @@ -145,4 +146,31 @@ typedef struct {
> >      GQueue *qmp_requests;
> >  } MonitorQMP;
> >  
> > +/**
> > + * Is @mon a QMP monitor?
> > + */
> > +static inline bool monitor_is_qmp(const Monitor *mon)
> > +{
> > +    return (mon->flags & MONITOR_USE_CONTROL);
> > +}
> > +
> > +typedef QTAILQ_HEAD(MonitorList, Monitor) MonitorList;
> > +extern IOThread *mon_iothread;
> > +extern QEMUBH *qmp_dispatcher_bh;
> > +extern QmpCommandList qmp_commands, qmp_cap_negotiation_commands;
> > +extern QemuMutex monitor_lock;
> > +extern MonitorList mon_list;
> > +extern int mon_refcount;
> > +
> > +int monitor_puts(Monitor *mon, const char *str);
> > +void monitor_data_init(Monitor *mon, int flags, bool skip_flush,
> > +                       bool use_io_thread);
> > +int monitor_can_read(void *opaque);
> > +void monitor_list_append(Monitor *mon);
> > +void monitor_fdsets_cleanup(void);
> > +
> > +void qmp_send_response(MonitorQMP *mon, const QDict *rsp);
> > +void monitor_data_destroy_qmp(MonitorQMP *mon);
> > +void monitor_qmp_bh_dispatcher(void *data);
> > +
> >  #endif
> 
> I trust you these are indeed all needed.

The linker said so. :-)

> > diff --git a/monitor/qmp.c b/monitor/qmp.c
> > new file mode 100644
> > index 0000000000..d425b0f2ba
> > --- /dev/null
> > +++ b/monitor/qmp.c
> > @@ -0,0 +1,404 @@
> > +/*
> > + * QEMU monitor
> > + *
> > + * Copyright (c) 2003-2004 Fabrice Bellard
> 
> I'm pretty confident nothing in this file is actually due to Fabrice.
> 
> > + *
> > + * Permission is hereby granted, free of charge, to any person obtaining a copy
> > + * of this software and associated documentation files (the "Software"), to deal
> > + * in the Software without restriction, including without limitation the rights
> > + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> > + * copies of the Software, and to permit persons to whom the Software is
> > + * furnished to do so, subject to the following conditions:
> > + *
> > + * The above copyright notice and this permission notice shall be included in
> > + * all copies or substantial portions of the Software.
> > + *
> > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> > + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> > + * THE SOFTWARE.
> > + */
> 
> We inherit the non-standard license regardless.  Lesson learned: do not
> add substantial code to source files with a non-standard license.

Yes. Nothing I can change here now, though. The legally safe way for
splitting files is to copy the license header.

> > +
> > +#include "qemu/osdep.h"
> > +#include "monitor_int.h"
> > +
> > +#include "chardev/char-io.h"
> > +
> > +#include "qapi/error.h"
> > +#include "qapi/qmp/qjson.h"
> > +#include "qapi/qmp/qstring.h"
> > +#include "qapi/qmp/qlist.h"
> > +#include "qapi/qapi-commands-misc.h"
> > +
> > +#include "trace.h"
> 
> Please sort the includes alphabetically (except qemu/osdep.h, of
> course).

In other words, move monitor_int.h down and remove the empty lines?

I like separating header files by "category", but that's a matter of
taste. I'll follow yours if you tell me whether I understood it
correctly.

> > +
> > +struct QMPRequest {
> > +    /* Owner of the request */
> > +    MonitorQMP *mon;
> > +    /*
> > +     * Request object to be handled or Error to be reported
> > +     * (exactly one of them is non-null)
> > +     */
> > +    QObject *req;
> > +    Error *err;
> > +};
> > +typedef struct QMPRequest QMPRequest;
> 
> Please fuse these two.

This is a code motion patch. Are you sure? [y/n]

Kevin