qemu/include/monitor/monitor.h
Markus Armbruster 0587568780 qmp: Dumb down how we run QMP command registration
The way we get QMP commands registered is high tech:

* qapi-commands.py generates qmp_init_marshal() that does the actual work

* it also generates the magic to register it as a MODULE_INIT_QAPI
  function, so it runs when someone calls
  module_call_init(MODULE_INIT_QAPI)

* main() calls module_call_init()

QEMU needs to register a few non-qapified commands.  Same high tech
works: monitor.c has its own qmp_init_marshal() along with the magic
to make it run in module_call_init(MODULE_INIT_QAPI).

QEMU also needs to unregister commands that are not wanted in this
build's configuration (commit 5032a16).  Simple enough:
qmp_unregister_commands_hack().  The difficulty is to make it run
after the generated qmp_init_marshal().  We can't simply run it in
monitor.c's qmp_init_marshal(), because the order in which the
registered functions run is indeterminate.  So qmp_init_marshal()
registers qmp_unregister_commands_hack() separately.  Since
registering *appends* to the list of registered functions, this will
make it run after all the functions that have been registered already.

I suspect it takes a long and expensive computer science education to
not find this silly.

Dumb it down as follows:

* Drop MODULE_INIT_QAPI entirely

* Give the generated qmp_init_marshal() external linkage.

* Call it instead of module_call_init(MODULE_INIT_QAPI)

* Except in QEMU proper, call new monitor_init_qmp_commands() that in
  turn calls the generated qmp_init_marshal(), registers the
  additional commands and unregisters the unwanted ones.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1488544368-30622-5-git-send-email-armbru@redhat.com>
2017-03-05 09:02:10 +01:00

57 lines
1.9 KiB
C

#ifndef MONITOR_H
#define MONITOR_H
#include "qemu-common.h"
#include "qapi/qmp/qdict.h"
#include "block/block.h"
#include "qemu/readline.h"
extern Monitor *cur_mon;
/* flags for monitor_init */
/* 0x01 unused */
#define MONITOR_USE_READLINE 0x02
#define MONITOR_USE_CONTROL 0x04
#define MONITOR_USE_PRETTY 0x08
bool monitor_cur_is_qmp(void);
void monitor_init_qmp_commands(void);
void monitor_init(Chardev *chr, int flags);
void monitor_cleanup(void);
int monitor_suspend(Monitor *mon);
void monitor_resume(Monitor *mon);
int monitor_read_bdrv_key_start(Monitor *mon, BlockDriverState *bs,
BlockCompletionFunc *completion_cb,
void *opaque);
int monitor_read_block_device_key(Monitor *mon, const char *device,
BlockCompletionFunc *completion_cb,
void *opaque);
int monitor_get_fd(Monitor *mon, const char *fdname, Error **errp);
int monitor_fd_param(Monitor *mon, const char *fdname, Error **errp);
void monitor_vprintf(Monitor *mon, const char *fmt, va_list ap)
GCC_FMT_ATTR(2, 0);
void monitor_printf(Monitor *mon, const char *fmt, ...) GCC_FMT_ATTR(2, 3);
int monitor_fprintf(FILE *stream, const char *fmt, ...) GCC_FMT_ATTR(2, 3);
void monitor_flush(Monitor *mon);
int monitor_set_cpu(int cpu_index);
int monitor_get_cpu_index(void);
void monitor_read_command(Monitor *mon, int show_prompt);
int monitor_read_password(Monitor *mon, ReadLineFunc *readline_func,
void *opaque);
AddfdInfo *monitor_fdset_add_fd(int fd, bool has_fdset_id, int64_t fdset_id,
bool has_opaque, const char *opaque,
Error **errp);
int monitor_fdset_get_fd(int64_t fdset_id, int flags);
int monitor_fdset_dup_fd_add(int64_t fdset_id, int dup_fd);
void monitor_fdset_dup_fd_remove(int dup_fd);
int monitor_fdset_dup_fd_find(int dup_fd);
#endif /* MONITOR_H */