qemu/qom/object.c

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/*
* QEMU Object Model
*
* Copyright IBM, Corp. 2011
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/object.h"
#include "qemu-common.h"
#include "qapi/qapi-visit-core.h"
/* TODO: replace QObject with a simpler visitor to avoid a dependency
* of the QOM core on QObject? */
#include "qemu/qom-qobject.h"
#include "qobject.h"
#include "qbool.h"
#include "qint.h"
#include "qstring.h"
#define MAX_INTERFACES 32
typedef struct InterfaceImpl InterfaceImpl;
typedef struct TypeImpl TypeImpl;
struct InterfaceImpl
{
const char *parent;
void (*interface_initfn)(ObjectClass *class, void *data);
TypeImpl *type;
};
struct TypeImpl
{
const char *name;
size_t class_size;
size_t instance_size;
void (*class_init)(ObjectClass *klass, void *data);
void (*class_finalize)(ObjectClass *klass, void *data);
void *class_data;
void (*instance_init)(Object *obj);
void (*instance_finalize)(Object *obj);
bool abstract;
const char *parent;
TypeImpl *parent_type;
ObjectClass *class;
int num_interfaces;
InterfaceImpl interfaces[MAX_INTERFACES];
};
typedef struct Interface
{
Object parent;
Object *obj;
} Interface;
#define INTERFACE(obj) OBJECT_CHECK(Interface, obj, TYPE_INTERFACE)
static Type type_interface;
static GHashTable *type_table_get(void)
{
static GHashTable *type_table;
if (type_table == NULL) {
type_table = g_hash_table_new(g_str_hash, g_str_equal);
}
return type_table;
}
static void type_table_add(TypeImpl *ti)
{
g_hash_table_insert(type_table_get(), (void *)ti->name, ti);
}
static TypeImpl *type_table_lookup(const char *name)
{
return g_hash_table_lookup(type_table_get(), name);
}
TypeImpl *type_register(const TypeInfo *info)
{
TypeImpl *ti = g_malloc0(sizeof(*ti));
g_assert(info->name != NULL);
if (type_table_lookup(info->name) != NULL) {
fprintf(stderr, "Registering `%s' which already exists\n", info->name);
abort();
}
ti->name = g_strdup(info->name);
ti->parent = g_strdup(info->parent);
ti->class_size = info->class_size;
ti->instance_size = info->instance_size;
ti->class_init = info->class_init;
ti->class_finalize = info->class_finalize;
ti->class_data = info->class_data;
ti->instance_init = info->instance_init;
ti->instance_finalize = info->instance_finalize;
ti->abstract = info->abstract;
if (info->interfaces) {
int i;
for (i = 0; info->interfaces[i].type; i++) {
ti->interfaces[i].parent = info->interfaces[i].type;
ti->interfaces[i].interface_initfn = info->interfaces[i].interface_initfn;
ti->num_interfaces++;
}
}
type_table_add(ti);
return ti;
}
TypeImpl *type_register_static(const TypeInfo *info)
{
return type_register(info);
}
static TypeImpl *type_get_by_name(const char *name)
{
if (name == NULL) {
return NULL;
}
return type_table_lookup(name);
}
static TypeImpl *type_get_parent(TypeImpl *type)
{
if (!type->parent_type && type->parent) {
type->parent_type = type_get_by_name(type->parent);
g_assert(type->parent_type != NULL);
}
return type->parent_type;
}
static bool type_has_parent(TypeImpl *type)
{
return (type->parent != NULL);
}
static size_t type_class_get_size(TypeImpl *ti)
{
if (ti->class_size) {
return ti->class_size;
}
if (type_has_parent(ti)) {
return type_class_get_size(type_get_parent(ti));
}
return sizeof(ObjectClass);
}
static void type_class_interface_init(TypeImpl *ti, InterfaceImpl *iface)
{
TypeInfo info = {
.instance_size = sizeof(Interface),
.parent = iface->parent,
.class_size = sizeof(InterfaceClass),
.class_init = iface->interface_initfn,
.abstract = true,
};
char *name = g_strdup_printf("<%s::%s>", ti->name, iface->parent);
info.name = name;
iface->type = type_register(&info);
g_free(name);
}
static void type_class_init(TypeImpl *ti)
{
size_t class_size = sizeof(ObjectClass);
int i;
if (ti->class) {
return;
}
ti->class_size = type_class_get_size(ti);
ti->class = g_malloc0(ti->class_size);
ti->class->type = ti;
if (type_has_parent(ti)) {
TypeImpl *parent = type_get_parent(ti);
type_class_init(parent);
class_size = parent->class_size;
g_assert(parent->class_size <= ti->class_size);
memcpy((void *)ti->class + sizeof(ObjectClass),
(void *)parent->class + sizeof(ObjectClass),
parent->class_size - sizeof(ObjectClass));
}
memset((void *)ti->class + class_size, 0, ti->class_size - class_size);
for (i = 0; i < ti->num_interfaces; i++) {
type_class_interface_init(ti, &ti->interfaces[i]);
}
if (ti->class_init) {
ti->class_init(ti->class, ti->class_data);
}
}
static void object_interface_init(Object *obj, InterfaceImpl *iface)
{
TypeImpl *ti = iface->type;
Interface *iface_obj;
iface_obj = INTERFACE(object_new(ti->name));
iface_obj->obj = obj;
obj->interfaces = g_slist_prepend(obj->interfaces, iface_obj);
}
static void object_init_with_type(Object *obj, TypeImpl *ti)
{
int i;
if (type_has_parent(ti)) {
object_init_with_type(obj, type_get_parent(ti));
}
for (i = 0; i < ti->num_interfaces; i++) {
object_interface_init(obj, &ti->interfaces[i]);
}
if (ti->instance_init) {
ti->instance_init(obj);
}
}
void object_initialize_with_type(void *data, TypeImpl *type)
{
Object *obj = data;
g_assert(type != NULL);
g_assert(type->instance_size >= sizeof(ObjectClass));
type_class_init(type);
g_assert(type->abstract == false);
memset(obj, 0, type->instance_size);
obj->class = type->class;
QTAILQ_INIT(&obj->properties);
object_init_with_type(obj, type);
}
void object_initialize(void *data, const char *typename)
{
TypeImpl *type = type_get_by_name(typename);
object_initialize_with_type(data, type);
}
static void object_property_del_all(Object *obj)
{
while (!QTAILQ_EMPTY(&obj->properties)) {
ObjectProperty *prop = QTAILQ_FIRST(&obj->properties);
QTAILQ_REMOVE(&obj->properties, prop, node);
if (prop->release) {
prop->release(obj, prop->name, prop->opaque);
}
g_free(prop->name);
g_free(prop->type);
g_free(prop);
}
}
static void object_property_del_child(Object *obj, Object *child, Error **errp)
{
ObjectProperty *prop;
QTAILQ_FOREACH(prop, &obj->properties, node) {
if (!strstart(prop->type, "child<", NULL)) {
continue;
}
if (prop->opaque == child) {
object_property_del(obj, prop->name, errp);
}
}
}
void object_unparent(Object *obj)
{
if (obj->parent) {
object_property_del_child(obj->parent, obj, NULL);
}
}
static void object_deinit(Object *obj, TypeImpl *type)
{
if (type->instance_finalize) {
type->instance_finalize(obj);
}
while (obj->interfaces) {
Interface *iface_obj = obj->interfaces->data;
obj->interfaces = g_slist_delete_link(obj->interfaces, obj->interfaces);
object_delete(OBJECT(iface_obj));
}
if (type_has_parent(type)) {
object_deinit(obj, type_get_parent(type));
}
object_unparent(obj);
}
void object_finalize(void *data)
{
Object *obj = data;
TypeImpl *ti = obj->class->type;
object_deinit(obj, ti);
object_property_del_all(obj);
g_assert(obj->ref == 0);
}
Object *object_new_with_type(Type type)
{
Object *obj;
g_assert(type != NULL);
obj = g_malloc(type->instance_size);
object_initialize_with_type(obj, type);
object_ref(obj);
return obj;
}
Object *object_new(const char *typename)
{
TypeImpl *ti = type_get_by_name(typename);
return object_new_with_type(ti);
}
void object_delete(Object *obj)
{
object_unref(obj);
g_assert(obj->ref == 0);
g_free(obj);
}
static bool type_is_ancestor(TypeImpl *type, TypeImpl *target_type)
{
assert(target_type);
/* Check if typename is a direct ancestor of type */
while (type) {
if (type == target_type) {
return true;
}
type = type_get_parent(type);
}
return false;
}
static bool object_is_type(Object *obj, TypeImpl *target_type)
{
return !target_type || type_is_ancestor(obj->class->type, target_type);
}
Object *object_dynamic_cast(Object *obj, const char *typename)
{
TypeImpl *target_type = type_get_by_name(typename);
GSList *i;
/* Check if typename is a direct ancestor. Special-case TYPE_OBJECT,
* we want to go back from interfaces to the parent.
*/
if (target_type && object_is_type(obj, target_type)) {
return obj;
}
/* Check if obj is an interface and its containing object is a direct
* ancestor of typename. In principle we could do this test at the very
* beginning of object_dynamic_cast, avoiding a second call to
* object_is_type. However, casting between interfaces is relatively
* rare, and object_is_type(obj, type_interface) would fail almost always.
*
* Perhaps we could add a magic value to the object header for increased
* (run-time) type safety and to speed up tests like this one. If we ever
* do that we can revisit the order here.
*/
if (object_is_type(obj, type_interface)) {
assert(!obj->interfaces);
obj = INTERFACE(obj)->obj;
if (object_is_type(obj, target_type)) {
return obj;
}
}
if (!target_type) {
return obj;
}
/* Check if obj has an interface of typename */
for (i = obj->interfaces; i; i = i->next) {
Interface *iface = i->data;
if (object_is_type(OBJECT(iface), target_type)) {
return OBJECT(iface);
}
}
return NULL;
}
static void register_types(void)
{
static TypeInfo interface_info = {
.name = TYPE_INTERFACE,
.instance_size = sizeof(Interface),
.abstract = true,
};
type_interface = type_register_static(&interface_info);
}
type_init(register_types)
Object *object_dynamic_cast_assert(Object *obj, const char *typename)
{
Object *inst;
inst = object_dynamic_cast(obj, typename);
if (!inst) {
fprintf(stderr, "Object %p is not an instance of type %s\n",
obj, typename);
abort();
}
return inst;
}
ObjectClass *object_class_dynamic_cast(ObjectClass *class,
const char *typename)
{
TypeImpl *target_type = type_get_by_name(typename);
TypeImpl *type = class->type;
while (type) {
if (type == target_type) {
return class;
}
type = type_get_parent(type);
}
return NULL;
}
ObjectClass *object_class_dynamic_cast_assert(ObjectClass *class,
const char *typename)
{
ObjectClass *ret = object_class_dynamic_cast(class, typename);
if (!ret) {
fprintf(stderr, "Object %p is not an instance of type %s\n",
class, typename);
abort();
}
return ret;
}
const char *object_get_typename(Object *obj)
{
return obj->class->type->name;
}
ObjectClass *object_get_class(Object *obj)
{
return obj->class;
}
const char *object_class_get_name(ObjectClass *klass)
{
return klass->type->name;
}
ObjectClass *object_class_by_name(const char *typename)
{
TypeImpl *type = type_get_by_name(typename);
if (!type) {
return NULL;
}
type_class_init(type);
return type->class;
}
typedef struct OCFData
{
void (*fn)(ObjectClass *klass, void *opaque);
const char *implements_type;
bool include_abstract;
void *opaque;
} OCFData;
static void object_class_foreach_tramp(gpointer key, gpointer value,
gpointer opaque)
{
OCFData *data = opaque;
TypeImpl *type = value;
ObjectClass *k;
type_class_init(type);
k = type->class;
if (!data->include_abstract && type->abstract) {
return;
}
if (data->implements_type &&
!object_class_dynamic_cast(k, data->implements_type)) {
return;
}
data->fn(k, data->opaque);
}
void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
const char *implements_type, bool include_abstract,
void *opaque)
{
OCFData data = { fn, implements_type, include_abstract, opaque };
g_hash_table_foreach(type_table_get(), object_class_foreach_tramp, &data);
}
void object_ref(Object *obj)
{
obj->ref++;
}
void object_unref(Object *obj)
{
g_assert(obj->ref > 0);
obj->ref--;
/* parent always holds a reference to its children */
if (obj->ref == 0) {
object_finalize(obj);
}
}
void object_property_add(Object *obj, const char *name, const char *type,
ObjectPropertyAccessor *get,
ObjectPropertyAccessor *set,
ObjectPropertyRelease *release,
void *opaque, Error **errp)
{
ObjectProperty *prop = g_malloc0(sizeof(*prop));
prop->name = g_strdup(name);
prop->type = g_strdup(type);
prop->get = get;
prop->set = set;
prop->release = release;
prop->opaque = opaque;
QTAILQ_INSERT_TAIL(&obj->properties, prop, node);
}
static ObjectProperty *object_property_find(Object *obj, const char *name)
{
ObjectProperty *prop;
QTAILQ_FOREACH(prop, &obj->properties, node) {
if (strcmp(prop->name, name) == 0) {
return prop;
}
}
return NULL;
}
void object_property_del(Object *obj, const char *name, Error **errp)
{
ObjectProperty *prop = object_property_find(obj, name);
QTAILQ_REMOVE(&obj->properties, prop, node);
prop->release(obj, prop->name, prop->opaque);
g_free(prop->name);
g_free(prop->type);
g_free(prop);
}
void object_property_get(Object *obj, Visitor *v, const char *name,
Error **errp)
{
ObjectProperty *prop = object_property_find(obj, name);
if (prop == NULL) {
error_set(errp, QERR_PROPERTY_NOT_FOUND, "", name);
return;
}
if (!prop->get) {
error_set(errp, QERR_PERMISSION_DENIED);
} else {
prop->get(obj, v, prop->opaque, name, errp);
}
}
void object_property_set(Object *obj, Visitor *v, const char *name,
Error **errp)
{
ObjectProperty *prop = object_property_find(obj, name);
if (prop == NULL) {
error_set(errp, QERR_PROPERTY_NOT_FOUND, "", name);
return;
}
if (!prop->set) {
error_set(errp, QERR_PERMISSION_DENIED);
} else {
prop->set(obj, v, prop->opaque, name, errp);
}
}
void object_property_set_str(Object *obj, const char *value,
const char *name, Error **errp)
{
QString *qstr = qstring_from_str(value);
object_property_set_qobject(obj, QOBJECT(qstr), name, errp);
QDECREF(qstr);
}
char *object_property_get_str(Object *obj, const char *name,
Error **errp)
{
QObject *ret = object_property_get_qobject(obj, name, errp);
QString *qstring;
char *retval;
if (!ret) {
return NULL;
}
qstring = qobject_to_qstring(ret);
if (!qstring) {
error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "string");
retval = NULL;
} else {
retval = g_strdup(qstring_get_str(qstring));
}
QDECREF(qstring);
return retval;
}
void object_property_set_link(Object *obj, Object *value,
const char *name, Error **errp)
{
object_property_set_str(obj, object_get_canonical_path(value),
name, errp);
}
Object *object_property_get_link(Object *obj, const char *name,
Error **errp)
{
char *str = object_property_get_str(obj, name, errp);
Object *target = NULL;
if (str && *str) {
target = object_resolve_path(str, NULL);
if (!target) {
error_set(errp, QERR_DEVICE_NOT_FOUND, str);
}
}
g_free(str);
return target;
}
void object_property_set_bool(Object *obj, bool value,
const char *name, Error **errp)
{
QBool *qbool = qbool_from_int(value);
object_property_set_qobject(obj, QOBJECT(qbool), name, errp);
QDECREF(qbool);
}
bool object_property_get_bool(Object *obj, const char *name,
Error **errp)
{
QObject *ret = object_property_get_qobject(obj, name, errp);
QBool *qbool;
bool retval;
if (!ret) {
return false;
}
qbool = qobject_to_qbool(ret);
if (!qbool) {
error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "boolean");
retval = false;
} else {
retval = qbool_get_int(qbool);
}
QDECREF(qbool);
return retval;
}
void object_property_set_int(Object *obj, int64_t value,
const char *name, Error **errp)
{
QInt *qint = qint_from_int(value);
object_property_set_qobject(obj, QOBJECT(qint), name, errp);
QDECREF(qint);
}
int64_t object_property_get_int(Object *obj, const char *name,
Error **errp)
{
QObject *ret = object_property_get_qobject(obj, name, errp);
QInt *qint;
int64_t retval;
if (!ret) {
return -1;
}
qint = qobject_to_qint(ret);
if (!qint) {
error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "int");
retval = -1;
} else {
retval = qint_get_int(qint);
}
QDECREF(qint);
return retval;
}
const char *object_property_get_type(Object *obj, const char *name, Error **errp)
{
ObjectProperty *prop = object_property_find(obj, name);
if (prop == NULL) {
error_set(errp, QERR_PROPERTY_NOT_FOUND, "", name);
return NULL;
}
return prop->type;
}
Object *object_get_root(void)
{
static Object *root;
if (!root) {
root = object_new("container");
}
return root;
}
static void object_get_child_property(Object *obj, Visitor *v, void *opaque,
const char *name, Error **errp)
{
Object *child = opaque;
gchar *path;
path = object_get_canonical_path(child);
visit_type_str(v, &path, name, errp);
g_free(path);
}
static void object_finalize_child_property(Object *obj, const char *name,
void *opaque)
{
Object *child = opaque;
object_unref(child);
}
void object_property_add_child(Object *obj, const char *name,
Object *child, Error **errp)
{
gchar *type;
/* Registering an interface object in the composition tree will mightily
* confuse object_get_canonical_path (which, on the other hand, knows how
* to get the canonical path of an interface object).
*/
assert(!object_is_type(obj, type_interface));
type = g_strdup_printf("child<%s>", object_get_typename(OBJECT(child)));
object_property_add(obj, name, type, object_get_child_property,
NULL, object_finalize_child_property, child, errp);
object_ref(child);
g_assert(child->parent == NULL);
child->parent = obj;
g_free(type);
}
static void object_get_link_property(Object *obj, Visitor *v, void *opaque,
const char *name, Error **errp)
{
Object **child = opaque;
gchar *path;
if (*child) {
path = object_get_canonical_path(*child);
visit_type_str(v, &path, name, errp);
g_free(path);
} else {
path = (gchar *)"";
visit_type_str(v, &path, name, errp);
}
}
static void object_set_link_property(Object *obj, Visitor *v, void *opaque,
const char *name, Error **errp)
{
Object **child = opaque;
bool ambiguous = false;
const char *type;
char *path;
gchar *target_type;
type = object_property_get_type(obj, name, NULL);
visit_type_str(v, &path, name, errp);
if (*child) {
object_unref(*child);
*child = NULL;
}
if (strcmp(path, "") != 0) {
Object *target;
/* Go from link<FOO> to FOO. */
target_type = g_strndup(&type[5], strlen(type) - 6);
target = object_resolve_path_type(path, target_type, &ambiguous);
if (ambiguous) {
error_set(errp, QERR_AMBIGUOUS_PATH, path);
} else if (target) {
object_ref(target);
*child = target;
} else {
target = object_resolve_path(path, &ambiguous);
if (target || ambiguous) {
error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, target_type);
} else {
error_set(errp, QERR_DEVICE_NOT_FOUND, path);
}
}
g_free(target_type);
}
g_free(path);
}
void object_property_add_link(Object *obj, const char *name,
const char *type, Object **child,
Error **errp)
{
gchar *full_type;
full_type = g_strdup_printf("link<%s>", type);
object_property_add(obj, name, full_type,
object_get_link_property,
object_set_link_property,
NULL, child, errp);
g_free(full_type);
}
gchar *object_get_canonical_path(Object *obj)
{
Object *root = object_get_root();
char *newpath = NULL, *path = NULL;
if (object_is_type(obj, type_interface)) {
obj = INTERFACE(obj)->obj;
}
while (obj != root) {
ObjectProperty *prop = NULL;
g_assert(obj->parent != NULL);
QTAILQ_FOREACH(prop, &obj->parent->properties, node) {
if (!strstart(prop->type, "child<", NULL)) {
continue;
}
if (prop->opaque == obj) {
if (path) {
newpath = g_strdup_printf("%s/%s", prop->name, path);
g_free(path);
path = newpath;
} else {
path = g_strdup(prop->name);
}
break;
}
}
g_assert(prop != NULL);
obj = obj->parent;
}
newpath = g_strdup_printf("/%s", path);
g_free(path);
return newpath;
}
static Object *object_resolve_abs_path(Object *parent,
gchar **parts,
const char *typename,
int index)
{
ObjectProperty *prop;
Object *child;
if (parts[index] == NULL) {
return object_dynamic_cast(parent, typename);
}
if (strcmp(parts[index], "") == 0) {
return object_resolve_abs_path(parent, parts, typename, index + 1);
}
prop = object_property_find(parent, parts[index]);
if (prop == NULL) {
return NULL;
}
child = NULL;
if (strstart(prop->type, "link<", NULL)) {
Object **pchild = prop->opaque;
if (*pchild) {
child = *pchild;
}
} else if (strstart(prop->type, "child<", NULL)) {
child = prop->opaque;
}
if (!child) {
return NULL;
}
return object_resolve_abs_path(child, parts, typename, index + 1);
}
static Object *object_resolve_partial_path(Object *parent,
gchar **parts,
const char *typename,
bool *ambiguous)
{
Object *obj;
ObjectProperty *prop;
obj = object_resolve_abs_path(parent, parts, typename, 0);
QTAILQ_FOREACH(prop, &parent->properties, node) {
Object *found;
if (!strstart(prop->type, "child<", NULL)) {
continue;
}
found = object_resolve_partial_path(prop->opaque, parts,
typename, ambiguous);
if (found) {
if (obj) {
if (ambiguous) {
*ambiguous = true;
}
return NULL;
}
obj = found;
}
if (ambiguous && *ambiguous) {
return NULL;
}
}
return obj;
}
Object *object_resolve_path_type(const char *path, const char *typename,
bool *ambiguous)
{
bool partial_path = true;
Object *obj;
gchar **parts;
parts = g_strsplit(path, "/", 0);
if (parts == NULL || parts[0] == NULL) {
g_strfreev(parts);
return object_get_root();
}
if (strcmp(parts[0], "") == 0) {
partial_path = false;
}
if (partial_path) {
if (ambiguous) {
*ambiguous = false;
}
obj = object_resolve_partial_path(object_get_root(), parts,
typename, ambiguous);
} else {
obj = object_resolve_abs_path(object_get_root(), parts, typename, 1);
}
g_strfreev(parts);
return obj;
}
Object *object_resolve_path(const char *path, bool *ambiguous)
{
return object_resolve_path_type(path, TYPE_OBJECT, ambiguous);
}
typedef struct StringProperty
{
char *(*get)(Object *, Error **);
void (*set)(Object *, const char *, Error **);
} StringProperty;
static void property_get_str(Object *obj, Visitor *v, void *opaque,
const char *name, Error **errp)
{
StringProperty *prop = opaque;
char *value;
value = prop->get(obj, errp);
if (value) {
visit_type_str(v, &value, name, errp);
g_free(value);
}
}
static void property_set_str(Object *obj, Visitor *v, void *opaque,
const char *name, Error **errp)
{
StringProperty *prop = opaque;
char *value;
Error *local_err = NULL;
visit_type_str(v, &value, name, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
prop->set(obj, value, errp);
g_free(value);
}
static void property_release_str(Object *obj, const char *name,
void *opaque)
{
StringProperty *prop = opaque;
g_free(prop);
}
void object_property_add_str(Object *obj, const char *name,
char *(*get)(Object *, Error **),
void (*set)(Object *, const char *, Error **),
Error **errp)
{
StringProperty *prop = g_malloc0(sizeof(*prop));
prop->get = get;
prop->set = set;
object_property_add(obj, name, "string",
get ? property_get_str : NULL,
set ? property_set_str : NULL,
property_release_str,
prop, errp);
}