xref: /qemu/include/qom/object.h (revision 7271a819)
1 /*
2  * QEMU Object Model
3  *
4  * Copyright IBM, Corp. 2011
5  *
6  * Authors:
7  *  Anthony Liguori   <aliguori@us.ibm.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
10  * See the COPYING file in the top-level directory.
11  *
12  */
13 
14 #ifndef QEMU_OBJECT_H
15 #define QEMU_OBJECT_H
16 
17 #include "qapi-types.h"
18 #include "qemu/queue.h"
19 
20 struct TypeImpl;
21 typedef struct TypeImpl *Type;
22 
23 typedef struct ObjectClass ObjectClass;
24 typedef struct Object Object;
25 
26 typedef struct TypeInfo TypeInfo;
27 
28 typedef struct InterfaceClass InterfaceClass;
29 typedef struct InterfaceInfo InterfaceInfo;
30 
31 #define TYPE_OBJECT "object"
32 
33 /**
34  * SECTION:object.h
35  * @title:Base Object Type System
36  * @short_description: interfaces for creating new types and objects
37  *
38  * The QEMU Object Model provides a framework for registering user creatable
39  * types and instantiating objects from those types.  QOM provides the following
40  * features:
41  *
42  *  - System for dynamically registering types
43  *  - Support for single-inheritance of types
44  *  - Multiple inheritance of stateless interfaces
45  *
46  * <example>
47  *   <title>Creating a minimal type</title>
48  *   <programlisting>
49  * #include "qdev.h"
50  *
51  * #define TYPE_MY_DEVICE "my-device"
52  *
53  * // No new virtual functions: we can reuse the typedef for the
54  * // superclass.
55  * typedef DeviceClass MyDeviceClass;
56  * typedef struct MyDevice
57  * {
58  *     DeviceState parent;
59  *
60  *     int reg0, reg1, reg2;
61  * } MyDevice;
62  *
63  * static const TypeInfo my_device_info = {
64  *     .name = TYPE_MY_DEVICE,
65  *     .parent = TYPE_DEVICE,
66  *     .instance_size = sizeof(MyDevice),
67  * };
68  *
69  * static void my_device_register_types(void)
70  * {
71  *     type_register_static(&my_device_info);
72  * }
73  *
74  * type_init(my_device_register_types)
75  *   </programlisting>
76  * </example>
77  *
78  * In the above example, we create a simple type that is described by #TypeInfo.
79  * #TypeInfo describes information about the type including what it inherits
80  * from, the instance and class size, and constructor/destructor hooks.
81  *
82  * Every type has an #ObjectClass associated with it.  #ObjectClass derivatives
83  * are instantiated dynamically but there is only ever one instance for any
84  * given type.  The #ObjectClass typically holds a table of function pointers
85  * for the virtual methods implemented by this type.
86  *
87  * Using object_new(), a new #Object derivative will be instantiated.  You can
88  * cast an #Object to a subclass (or base-class) type using
89  * object_dynamic_cast().  You typically want to define macro wrappers around
90  * OBJECT_CHECK() and OBJECT_CLASS_CHECK() to make it easier to convert to a
91  * specific type:
92  *
93  * <example>
94  *   <title>Typecasting macros</title>
95  *   <programlisting>
96  *    #define MY_DEVICE_GET_CLASS(obj) \
97  *       OBJECT_GET_CLASS(MyDeviceClass, obj, TYPE_MY_DEVICE)
98  *    #define MY_DEVICE_CLASS(klass) \
99  *       OBJECT_CLASS_CHECK(MyDeviceClass, klass, TYPE_MY_DEVICE)
100  *    #define MY_DEVICE(obj) \
101  *       OBJECT_CHECK(MyDevice, obj, TYPE_MY_DEVICE)
102  *   </programlisting>
103  * </example>
104  *
105  * # Class Initialization #
106  *
107  * Before an object is initialized, the class for the object must be
108  * initialized.  There is only one class object for all instance objects
109  * that is created lazily.
110  *
111  * Classes are initialized by first initializing any parent classes (if
112  * necessary).  After the parent class object has initialized, it will be
113  * copied into the current class object and any additional storage in the
114  * class object is zero filled.
115  *
116  * The effect of this is that classes automatically inherit any virtual
117  * function pointers that the parent class has already initialized.  All
118  * other fields will be zero filled.
119  *
120  * Once all of the parent classes have been initialized, #TypeInfo::class_init
121  * is called to let the class being instantiated provide default initialize for
122  * its virtual functions.  Here is how the above example might be modified
123  * to introduce an overridden virtual function:
124  *
125  * <example>
126  *   <title>Overriding a virtual function</title>
127  *   <programlisting>
128  * #include "qdev.h"
129  *
130  * void my_device_class_init(ObjectClass *klass, void *class_data)
131  * {
132  *     DeviceClass *dc = DEVICE_CLASS(klass);
133  *     dc->reset = my_device_reset;
134  * }
135  *
136  * static const TypeInfo my_device_info = {
137  *     .name = TYPE_MY_DEVICE,
138  *     .parent = TYPE_DEVICE,
139  *     .instance_size = sizeof(MyDevice),
140  *     .class_init = my_device_class_init,
141  * };
142  *   </programlisting>
143  * </example>
144  *
145  * Introducing new virtual methods requires a class to define its own
146  * struct and to add a .class_size member to the #TypeInfo.  Each method
147  * will also have a wrapper function to call it easily:
148  *
149  * <example>
150  *   <title>Defining an abstract class</title>
151  *   <programlisting>
152  * #include "qdev.h"
153  *
154  * typedef struct MyDeviceClass
155  * {
156  *     DeviceClass parent;
157  *
158  *     void (*frobnicate) (MyDevice *obj);
159  * } MyDeviceClass;
160  *
161  * static const TypeInfo my_device_info = {
162  *     .name = TYPE_MY_DEVICE,
163  *     .parent = TYPE_DEVICE,
164  *     .instance_size = sizeof(MyDevice),
165  *     .abstract = true, // or set a default in my_device_class_init
166  *     .class_size = sizeof(MyDeviceClass),
167  * };
168  *
169  * void my_device_frobnicate(MyDevice *obj)
170  * {
171  *     MyDeviceClass *klass = MY_DEVICE_GET_CLASS(obj);
172  *
173  *     klass->frobnicate(obj);
174  * }
175  *   </programlisting>
176  * </example>
177  *
178  * # Interfaces #
179  *
180  * Interfaces allow a limited form of multiple inheritance.  Instances are
181  * similar to normal types except for the fact that are only defined by
182  * their classes and never carry any state.  You can dynamically cast an object
183  * to one of its #Interface types and vice versa.
184  *
185  * # Methods #
186  *
187  * A <emphasis>method</emphasis> is a function within the namespace scope of
188  * a class. It usually operates on the object instance by passing it as a
189  * strongly-typed first argument.
190  * If it does not operate on an object instance, it is dubbed
191  * <emphasis>class method</emphasis>.
192  *
193  * Methods cannot be overloaded. That is, the #ObjectClass and method name
194  * uniquely identity the function to be called; the signature does not vary
195  * except for trailing varargs.
196  *
197  * Methods are always <emphasis>virtual</emphasis>. Overriding a method in
198  * #TypeInfo.class_init of a subclass leads to any user of the class obtained
199  * via OBJECT_GET_CLASS() accessing the overridden function.
200  * The original function is not automatically invoked. It is the responsibility
201  * of the overriding class to determine whether and when to invoke the method
202  * being overridden.
203  *
204  * To invoke the method being overridden, the preferred solution is to store
205  * the original value in the overriding class before overriding the method.
206  * This corresponds to |[ {super,base}.method(...) ]| in Java and C#
207  * respectively; this frees the overriding class from hardcoding its parent
208  * class, which someone might choose to change at some point.
209  *
210  * <example>
211  *   <title>Overriding a virtual method</title>
212  *   <programlisting>
213  * typedef struct MyState MyState;
214  *
215  * typedef void (*MyDoSomething)(MyState *obj);
216  *
217  * typedef struct MyClass {
218  *     ObjectClass parent_class;
219  *
220  *     MyDoSomething do_something;
221  * } MyClass;
222  *
223  * static void my_do_something(MyState *obj)
224  * {
225  *     // do something
226  * }
227  *
228  * static void my_class_init(ObjectClass *oc, void *data)
229  * {
230  *     MyClass *mc = MY_CLASS(oc);
231  *
232  *     mc->do_something = my_do_something;
233  * }
234  *
235  * static const TypeInfo my_type_info = {
236  *     .name = TYPE_MY,
237  *     .parent = TYPE_OBJECT,
238  *     .instance_size = sizeof(MyState),
239  *     .class_size = sizeof(MyClass),
240  *     .class_init = my_class_init,
241  * };
242  *
243  * typedef struct DerivedClass {
244  *     MyClass parent_class;
245  *
246  *     MyDoSomething parent_do_something;
247  * } DerivedClass;
248  *
249  * static void derived_do_something(MyState *obj)
250  * {
251  *     DerivedClass *dc = DERIVED_GET_CLASS(obj);
252  *
253  *     // do something here
254  *     dc->parent_do_something(obj);
255  *     // do something else here
256  * }
257  *
258  * static void derived_class_init(ObjectClass *oc, void *data)
259  * {
260  *     MyClass *mc = MY_CLASS(oc);
261  *     DerivedClass *dc = DERIVED_CLASS(oc);
262  *
263  *     dc->parent_do_something = mc->do_something;
264  *     mc->do_something = derived_do_something;
265  * }
266  *
267  * static const TypeInfo derived_type_info = {
268  *     .name = TYPE_DERIVED,
269  *     .parent = TYPE_MY,
270  *     .class_size = sizeof(DerivedClass),
271  *     .class_init = derived_class_init,
272  * };
273  *   </programlisting>
274  * </example>
275  *
276  * Alternatively, object_class_by_name() can be used to obtain the class and
277  * its non-overridden methods for a specific type. This would correspond to
278  * |[ MyClass::method(...) ]| in C++.
279  *
280  * The first example of such a QOM method was #CPUClass.reset,
281  * another example is #DeviceClass.realize.
282  */
283 
284 
285 /**
286  * ObjectPropertyAccessor:
287  * @obj: the object that owns the property
288  * @v: the visitor that contains the property data
289  * @name: the name of the property
290  * @opaque: the object property opaque
291  * @errp: a pointer to an Error that is filled if getting/setting fails.
292  *
293  * Called when trying to get/set a property.
294  */
295 typedef void (ObjectPropertyAccessor)(Object *obj,
296                                       Visitor *v,
297                                       const char *name,
298                                       void *opaque,
299                                       Error **errp);
300 
301 /**
302  * ObjectPropertyResolve:
303  * @obj: the object that owns the property
304  * @opaque: the opaque registered with the property
305  * @part: the name of the property
306  *
307  * Resolves the #Object corresponding to property @part.
308  *
309  * The returned object can also be used as a starting point
310  * to resolve a relative path starting with "@part".
311  *
312  * Returns: If @path is the path that led to @obj, the function
313  * returns the #Object corresponding to "@path/@part".
314  * If "@path/@part" is not a valid object path, it returns #NULL.
315  */
316 typedef Object *(ObjectPropertyResolve)(Object *obj,
317                                         void *opaque,
318                                         const char *part);
319 
320 /**
321  * ObjectPropertyRelease:
322  * @obj: the object that owns the property
323  * @name: the name of the property
324  * @opaque: the opaque registered with the property
325  *
326  * Called when a property is removed from a object.
327  */
328 typedef void (ObjectPropertyRelease)(Object *obj,
329                                      const char *name,
330                                      void *opaque);
331 
332 typedef struct ObjectProperty
333 {
334     gchar *name;
335     gchar *type;
336     gchar *description;
337     ObjectPropertyAccessor *get;
338     ObjectPropertyAccessor *set;
339     ObjectPropertyResolve *resolve;
340     ObjectPropertyRelease *release;
341     void *opaque;
342 } ObjectProperty;
343 
344 /**
345  * ObjectUnparent:
346  * @obj: the object that is being removed from the composition tree
347  *
348  * Called when an object is being removed from the QOM composition tree.
349  * The function should remove any backlinks from children objects to @obj.
350  */
351 typedef void (ObjectUnparent)(Object *obj);
352 
353 /**
354  * ObjectFree:
355  * @obj: the object being freed
356  *
357  * Called when an object's last reference is removed.
358  */
359 typedef void (ObjectFree)(void *obj);
360 
361 #define OBJECT_CLASS_CAST_CACHE 4
362 
363 /**
364  * ObjectClass:
365  *
366  * The base for all classes.  The only thing that #ObjectClass contains is an
367  * integer type handle.
368  */
369 struct ObjectClass
370 {
371     /*< private >*/
372     Type type;
373     GSList *interfaces;
374 
375     const char *object_cast_cache[OBJECT_CLASS_CAST_CACHE];
376     const char *class_cast_cache[OBJECT_CLASS_CAST_CACHE];
377 
378     ObjectUnparent *unparent;
379 
380     GHashTable *properties;
381 };
382 
383 /**
384  * Object:
385  *
386  * The base for all objects.  The first member of this object is a pointer to
387  * a #ObjectClass.  Since C guarantees that the first member of a structure
388  * always begins at byte 0 of that structure, as long as any sub-object places
389  * its parent as the first member, we can cast directly to a #Object.
390  *
391  * As a result, #Object contains a reference to the objects type as its
392  * first member.  This allows identification of the real type of the object at
393  * run time.
394  */
395 struct Object
396 {
397     /*< private >*/
398     ObjectClass *class;
399     ObjectFree *free;
400     GHashTable *properties;
401     uint32_t ref;
402     Object *parent;
403 };
404 
405 /**
406  * TypeInfo:
407  * @name: The name of the type.
408  * @parent: The name of the parent type.
409  * @instance_size: The size of the object (derivative of #Object).  If
410  *   @instance_size is 0, then the size of the object will be the size of the
411  *   parent object.
412  * @instance_init: This function is called to initialize an object.  The parent
413  *   class will have already been initialized so the type is only responsible
414  *   for initializing its own members.
415  * @instance_post_init: This function is called to finish initialization of
416  *   an object, after all @instance_init functions were called.
417  * @instance_finalize: This function is called during object destruction.  This
418  *   is called before the parent @instance_finalize function has been called.
419  *   An object should only free the members that are unique to its type in this
420  *   function.
421  * @abstract: If this field is true, then the class is considered abstract and
422  *   cannot be directly instantiated.
423  * @class_size: The size of the class object (derivative of #ObjectClass)
424  *   for this object.  If @class_size is 0, then the size of the class will be
425  *   assumed to be the size of the parent class.  This allows a type to avoid
426  *   implementing an explicit class type if they are not adding additional
427  *   virtual functions.
428  * @class_init: This function is called after all parent class initialization
429  *   has occurred to allow a class to set its default virtual method pointers.
430  *   This is also the function to use to override virtual methods from a parent
431  *   class.
432  * @class_base_init: This function is called for all base classes after all
433  *   parent class initialization has occurred, but before the class itself
434  *   is initialized.  This is the function to use to undo the effects of
435  *   memcpy from the parent class to the descendants.
436  * @class_finalize: This function is called during class destruction and is
437  *   meant to release and dynamic parameters allocated by @class_init.
438  * @class_data: Data to pass to the @class_init, @class_base_init and
439  *   @class_finalize functions.  This can be useful when building dynamic
440  *   classes.
441  * @interfaces: The list of interfaces associated with this type.  This
442  *   should point to a static array that's terminated with a zero filled
443  *   element.
444  */
445 struct TypeInfo
446 {
447     const char *name;
448     const char *parent;
449 
450     size_t instance_size;
451     void (*instance_init)(Object *obj);
452     void (*instance_post_init)(Object *obj);
453     void (*instance_finalize)(Object *obj);
454 
455     bool abstract;
456     size_t class_size;
457 
458     void (*class_init)(ObjectClass *klass, void *data);
459     void (*class_base_init)(ObjectClass *klass, void *data);
460     void (*class_finalize)(ObjectClass *klass, void *data);
461     void *class_data;
462 
463     InterfaceInfo *interfaces;
464 };
465 
466 /**
467  * OBJECT:
468  * @obj: A derivative of #Object
469  *
470  * Converts an object to a #Object.  Since all objects are #Objects,
471  * this function will always succeed.
472  */
473 #define OBJECT(obj) \
474     ((Object *)(obj))
475 
476 /**
477  * OBJECT_CLASS:
478  * @class: A derivative of #ObjectClass.
479  *
480  * Converts a class to an #ObjectClass.  Since all objects are #Objects,
481  * this function will always succeed.
482  */
483 #define OBJECT_CLASS(class) \
484     ((ObjectClass *)(class))
485 
486 /**
487  * OBJECT_CHECK:
488  * @type: The C type to use for the return value.
489  * @obj: A derivative of @type to cast.
490  * @name: The QOM typename of @type
491  *
492  * A type safe version of @object_dynamic_cast_assert.  Typically each class
493  * will define a macro based on this type to perform type safe dynamic_casts to
494  * this object type.
495  *
496  * If an invalid object is passed to this function, a run time assert will be
497  * generated.
498  */
499 #define OBJECT_CHECK(type, obj, name) \
500     ((type *)object_dynamic_cast_assert(OBJECT(obj), (name), \
501                                         __FILE__, __LINE__, __func__))
502 
503 /**
504  * OBJECT_CLASS_CHECK:
505  * @class_type: The C type to use for the return value.
506  * @class: A derivative class of @class_type to cast.
507  * @name: the QOM typename of @class_type.
508  *
509  * A type safe version of @object_class_dynamic_cast_assert.  This macro is
510  * typically wrapped by each type to perform type safe casts of a class to a
511  * specific class type.
512  */
513 #define OBJECT_CLASS_CHECK(class_type, class, name) \
514     ((class_type *)object_class_dynamic_cast_assert(OBJECT_CLASS(class), (name), \
515                                                __FILE__, __LINE__, __func__))
516 
517 /**
518  * OBJECT_GET_CLASS:
519  * @class: The C type to use for the return value.
520  * @obj: The object to obtain the class for.
521  * @name: The QOM typename of @obj.
522  *
523  * This function will return a specific class for a given object.  Its generally
524  * used by each type to provide a type safe macro to get a specific class type
525  * from an object.
526  */
527 #define OBJECT_GET_CLASS(class, obj, name) \
528     OBJECT_CLASS_CHECK(class, object_get_class(OBJECT(obj)), name)
529 
530 /**
531  * InterfaceInfo:
532  * @type: The name of the interface.
533  *
534  * The information associated with an interface.
535  */
536 struct InterfaceInfo {
537     const char *type;
538 };
539 
540 /**
541  * InterfaceClass:
542  * @parent_class: the base class
543  *
544  * The class for all interfaces.  Subclasses of this class should only add
545  * virtual methods.
546  */
547 struct InterfaceClass
548 {
549     ObjectClass parent_class;
550     /*< private >*/
551     ObjectClass *concrete_class;
552     Type interface_type;
553 };
554 
555 #define TYPE_INTERFACE "interface"
556 
557 /**
558  * INTERFACE_CLASS:
559  * @klass: class to cast from
560  * Returns: An #InterfaceClass or raise an error if cast is invalid
561  */
562 #define INTERFACE_CLASS(klass) \
563     OBJECT_CLASS_CHECK(InterfaceClass, klass, TYPE_INTERFACE)
564 
565 /**
566  * INTERFACE_CHECK:
567  * @interface: the type to return
568  * @obj: the object to convert to an interface
569  * @name: the interface type name
570  *
571  * Returns: @obj casted to @interface if cast is valid, otherwise raise error.
572  */
573 #define INTERFACE_CHECK(interface, obj, name) \
574     ((interface *)object_dynamic_cast_assert(OBJECT((obj)), (name), \
575                                              __FILE__, __LINE__, __func__))
576 
577 /**
578  * object_new:
579  * @typename: The name of the type of the object to instantiate.
580  *
581  * This function will initialize a new object using heap allocated memory.
582  * The returned object has a reference count of 1, and will be freed when
583  * the last reference is dropped.
584  *
585  * Returns: The newly allocated and instantiated object.
586  */
587 Object *object_new(const char *typename);
588 
589 /**
590  * object_new_with_props:
591  * @typename:  The name of the type of the object to instantiate.
592  * @parent: the parent object
593  * @id: The unique ID of the object
594  * @errp: pointer to error object
595  * @...: list of property names and values
596  *
597  * This function will initialize a new object using heap allocated memory.
598  * The returned object has a reference count of 1, and will be freed when
599  * the last reference is dropped.
600  *
601  * The @id parameter will be used when registering the object as a
602  * child of @parent in the composition tree.
603  *
604  * The variadic parameters are a list of pairs of (propname, propvalue)
605  * strings. The propname of %NULL indicates the end of the property
606  * list. If the object implements the user creatable interface, the
607  * object will be marked complete once all the properties have been
608  * processed.
609  *
610  * <example>
611  *   <title>Creating an object with properties</title>
612  *   <programlisting>
613  *   Error *err = NULL;
614  *   Object *obj;
615  *
616  *   obj = object_new_with_props(TYPE_MEMORY_BACKEND_FILE,
617  *                               object_get_objects_root(),
618  *                               "hostmem0",
619  *                               &err,
620  *                               "share", "yes",
621  *                               "mem-path", "/dev/shm/somefile",
622  *                               "prealloc", "yes",
623  *                               "size", "1048576",
624  *                               NULL);
625  *
626  *   if (!obj) {
627  *     g_printerr("Cannot create memory backend: %s\n",
628  *                error_get_pretty(err));
629  *   }
630  *   </programlisting>
631  * </example>
632  *
633  * The returned object will have one stable reference maintained
634  * for as long as it is present in the object hierarchy.
635  *
636  * Returns: The newly allocated, instantiated & initialized object.
637  */
638 Object *object_new_with_props(const char *typename,
639                               Object *parent,
640                               const char *id,
641                               Error **errp,
642                               ...) QEMU_SENTINEL;
643 
644 /**
645  * object_new_with_propv:
646  * @typename:  The name of the type of the object to instantiate.
647  * @parent: the parent object
648  * @id: The unique ID of the object
649  * @errp: pointer to error object
650  * @vargs: list of property names and values
651  *
652  * See object_new_with_props() for documentation.
653  */
654 Object *object_new_with_propv(const char *typename,
655                               Object *parent,
656                               const char *id,
657                               Error **errp,
658                               va_list vargs);
659 
660 /**
661  * object_set_props:
662  * @obj: the object instance to set properties on
663  * @errp: pointer to error object
664  * @...: list of property names and values
665  *
666  * This function will set a list of properties on an existing object
667  * instance.
668  *
669  * The variadic parameters are a list of pairs of (propname, propvalue)
670  * strings. The propname of %NULL indicates the end of the property
671  * list.
672  *
673  * <example>
674  *   <title>Update an object's properties</title>
675  *   <programlisting>
676  *   Error *err = NULL;
677  *   Object *obj = ...get / create object...;
678  *
679  *   obj = object_set_props(obj,
680  *                          &err,
681  *                          "share", "yes",
682  *                          "mem-path", "/dev/shm/somefile",
683  *                          "prealloc", "yes",
684  *                          "size", "1048576",
685  *                          NULL);
686  *
687  *   if (!obj) {
688  *     g_printerr("Cannot set properties: %s\n",
689  *                error_get_pretty(err));
690  *   }
691  *   </programlisting>
692  * </example>
693  *
694  * The returned object will have one stable reference maintained
695  * for as long as it is present in the object hierarchy.
696  *
697  * Returns: -1 on error, 0 on success
698  */
699 int object_set_props(Object *obj,
700                      Error **errp,
701                      ...) QEMU_SENTINEL;
702 
703 /**
704  * object_set_propv:
705  * @obj: the object instance to set properties on
706  * @errp: pointer to error object
707  * @vargs: list of property names and values
708  *
709  * See object_set_props() for documentation.
710  *
711  * Returns: -1 on error, 0 on success
712  */
713 int object_set_propv(Object *obj,
714                      Error **errp,
715                      va_list vargs);
716 
717 /**
718  * object_initialize:
719  * @obj: A pointer to the memory to be used for the object.
720  * @size: The maximum size available at @obj for the object.
721  * @typename: The name of the type of the object to instantiate.
722  *
723  * This function will initialize an object.  The memory for the object should
724  * have already been allocated.  The returned object has a reference count of 1,
725  * and will be finalized when the last reference is dropped.
726  */
727 void object_initialize(void *obj, size_t size, const char *typename);
728 
729 /**
730  * object_dynamic_cast:
731  * @obj: The object to cast.
732  * @typename: The @typename to cast to.
733  *
734  * This function will determine if @obj is-a @typename.  @obj can refer to an
735  * object or an interface associated with an object.
736  *
737  * Returns: This function returns @obj on success or #NULL on failure.
738  */
739 Object *object_dynamic_cast(Object *obj, const char *typename);
740 
741 /**
742  * object_dynamic_cast_assert:
743  *
744  * See object_dynamic_cast() for a description of the parameters of this
745  * function.  The only difference in behavior is that this function asserts
746  * instead of returning #NULL on failure if QOM cast debugging is enabled.
747  * This function is not meant to be called directly, but only through
748  * the wrapper macro OBJECT_CHECK.
749  */
750 Object *object_dynamic_cast_assert(Object *obj, const char *typename,
751                                    const char *file, int line, const char *func);
752 
753 /**
754  * object_get_class:
755  * @obj: A derivative of #Object
756  *
757  * Returns: The #ObjectClass of the type associated with @obj.
758  */
759 ObjectClass *object_get_class(Object *obj);
760 
761 /**
762  * object_get_typename:
763  * @obj: A derivative of #Object.
764  *
765  * Returns: The QOM typename of @obj.
766  */
767 const char *object_get_typename(const Object *obj);
768 
769 /**
770  * type_register_static:
771  * @info: The #TypeInfo of the new type.
772  *
773  * @info and all of the strings it points to should exist for the life time
774  * that the type is registered.
775  *
776  * Returns: the new #Type.
777  */
778 Type type_register_static(const TypeInfo *info);
779 
780 /**
781  * type_register:
782  * @info: The #TypeInfo of the new type
783  *
784  * Unlike type_register_static(), this call does not require @info or its
785  * string members to continue to exist after the call returns.
786  *
787  * Returns: the new #Type.
788  */
789 Type type_register(const TypeInfo *info);
790 
791 /**
792  * object_class_dynamic_cast_assert:
793  * @klass: The #ObjectClass to attempt to cast.
794  * @typename: The QOM typename of the class to cast to.
795  *
796  * See object_class_dynamic_cast() for a description of the parameters
797  * of this function.  The only difference in behavior is that this function
798  * asserts instead of returning #NULL on failure if QOM cast debugging is
799  * enabled.  This function is not meant to be called directly, but only through
800  * the wrapper macros OBJECT_CLASS_CHECK and INTERFACE_CHECK.
801  */
802 ObjectClass *object_class_dynamic_cast_assert(ObjectClass *klass,
803                                               const char *typename,
804                                               const char *file, int line,
805                                               const char *func);
806 
807 /**
808  * object_class_dynamic_cast:
809  * @klass: The #ObjectClass to attempt to cast.
810  * @typename: The QOM typename of the class to cast to.
811  *
812  * Returns: If @typename is a class, this function returns @klass if
813  * @typename is a subtype of @klass, else returns #NULL.
814  *
815  * If @typename is an interface, this function returns the interface
816  * definition for @klass if @klass implements it unambiguously; #NULL
817  * is returned if @klass does not implement the interface or if multiple
818  * classes or interfaces on the hierarchy leading to @klass implement
819  * it.  (FIXME: perhaps this can be detected at type definition time?)
820  */
821 ObjectClass *object_class_dynamic_cast(ObjectClass *klass,
822                                        const char *typename);
823 
824 /**
825  * object_class_get_parent:
826  * @klass: The class to obtain the parent for.
827  *
828  * Returns: The parent for @klass or %NULL if none.
829  */
830 ObjectClass *object_class_get_parent(ObjectClass *klass);
831 
832 /**
833  * object_class_get_name:
834  * @klass: The class to obtain the QOM typename for.
835  *
836  * Returns: The QOM typename for @klass.
837  */
838 const char *object_class_get_name(ObjectClass *klass);
839 
840 /**
841  * object_class_is_abstract:
842  * @klass: The class to obtain the abstractness for.
843  *
844  * Returns: %true if @klass is abstract, %false otherwise.
845  */
846 bool object_class_is_abstract(ObjectClass *klass);
847 
848 /**
849  * object_class_by_name:
850  * @typename: The QOM typename to obtain the class for.
851  *
852  * Returns: The class for @typename or %NULL if not found.
853  */
854 ObjectClass *object_class_by_name(const char *typename);
855 
856 void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
857                           const char *implements_type, bool include_abstract,
858                           void *opaque);
859 
860 /**
861  * object_class_get_list:
862  * @implements_type: The type to filter for, including its derivatives.
863  * @include_abstract: Whether to include abstract classes.
864  *
865  * Returns: A singly-linked list of the classes in reverse hashtable order.
866  */
867 GSList *object_class_get_list(const char *implements_type,
868                               bool include_abstract);
869 
870 /**
871  * object_ref:
872  * @obj: the object
873  *
874  * Increase the reference count of a object.  A object cannot be freed as long
875  * as its reference count is greater than zero.
876  */
877 void object_ref(Object *obj);
878 
879 /**
880  * object_unref:
881  * @obj: the object
882  *
883  * Decrease the reference count of a object.  A object cannot be freed as long
884  * as its reference count is greater than zero.
885  */
886 void object_unref(Object *obj);
887 
888 /**
889  * object_property_add:
890  * @obj: the object to add a property to
891  * @name: the name of the property.  This can contain any character except for
892  *  a forward slash.  In general, you should use hyphens '-' instead of
893  *  underscores '_' when naming properties.
894  * @type: the type name of the property.  This namespace is pretty loosely
895  *   defined.  Sub namespaces are constructed by using a prefix and then
896  *   to angle brackets.  For instance, the type 'virtio-net-pci' in the
897  *   'link' namespace would be 'link<virtio-net-pci>'.
898  * @get: The getter to be called to read a property.  If this is NULL, then
899  *   the property cannot be read.
900  * @set: the setter to be called to write a property.  If this is NULL,
901  *   then the property cannot be written.
902  * @release: called when the property is removed from the object.  This is
903  *   meant to allow a property to free its opaque upon object
904  *   destruction.  This may be NULL.
905  * @opaque: an opaque pointer to pass to the callbacks for the property
906  * @errp: returns an error if this function fails
907  *
908  * Returns: The #ObjectProperty; this can be used to set the @resolve
909  * callback for child and link properties.
910  */
911 ObjectProperty *object_property_add(Object *obj, const char *name,
912                                     const char *type,
913                                     ObjectPropertyAccessor *get,
914                                     ObjectPropertyAccessor *set,
915                                     ObjectPropertyRelease *release,
916                                     void *opaque, Error **errp);
917 
918 void object_property_del(Object *obj, const char *name, Error **errp);
919 
920 ObjectProperty *object_class_property_add(ObjectClass *klass, const char *name,
921                                           const char *type,
922                                           ObjectPropertyAccessor *get,
923                                           ObjectPropertyAccessor *set,
924                                           ObjectPropertyRelease *release,
925                                           void *opaque, Error **errp);
926 
927 /**
928  * object_property_find:
929  * @obj: the object
930  * @name: the name of the property
931  * @errp: returns an error if this function fails
932  *
933  * Look up a property for an object and return its #ObjectProperty if found.
934  */
935 ObjectProperty *object_property_find(Object *obj, const char *name,
936                                      Error **errp);
937 ObjectProperty *object_class_property_find(ObjectClass *klass, const char *name,
938                                            Error **errp);
939 
940 typedef struct ObjectPropertyIterator {
941     ObjectClass *nextclass;
942     GHashTableIter iter;
943 } ObjectPropertyIterator;
944 
945 /**
946  * object_property_iter_init:
947  * @obj: the object
948  *
949  * Initializes an iterator for traversing all properties
950  * registered against an object instance, its class and all parent classes.
951  *
952  * It is forbidden to modify the property list while iterating,
953  * whether removing or adding properties.
954  *
955  * Typical usage pattern would be
956  *
957  * <example>
958  *   <title>Using object property iterators</title>
959  *   <programlisting>
960  *   ObjectProperty *prop;
961  *   ObjectPropertyIterator iter;
962  *
963  *   object_property_iter_init(&iter, obj);
964  *   while ((prop = object_property_iter_next(&iter))) {
965  *     ... do something with prop ...
966  *   }
967  *   </programlisting>
968  * </example>
969  */
970 void object_property_iter_init(ObjectPropertyIterator *iter,
971                                Object *obj);
972 
973 /**
974  * object_property_iter_next:
975  * @iter: the iterator instance
976  *
977  * Return the next available property. If no further properties
978  * are available, a %NULL value will be returned and the @iter
979  * pointer should not be used again after this point without
980  * re-initializing it.
981  *
982  * Returns: the next property, or %NULL when all properties
983  * have been traversed.
984  */
985 ObjectProperty *object_property_iter_next(ObjectPropertyIterator *iter);
986 
987 void object_unparent(Object *obj);
988 
989 /**
990  * object_property_get:
991  * @obj: the object
992  * @v: the visitor that will receive the property value.  This should be an
993  *   Output visitor and the data will be written with @name as the name.
994  * @name: the name of the property
995  * @errp: returns an error if this function fails
996  *
997  * Reads a property from a object.
998  */
999 void object_property_get(Object *obj, Visitor *v, const char *name,
1000                          Error **errp);
1001 
1002 /**
1003  * object_property_set_str:
1004  * @value: the value to be written to the property
1005  * @name: the name of the property
1006  * @errp: returns an error if this function fails
1007  *
1008  * Writes a string value to a property.
1009  */
1010 void object_property_set_str(Object *obj, const char *value,
1011                              const char *name, Error **errp);
1012 
1013 /**
1014  * object_property_get_str:
1015  * @obj: the object
1016  * @name: the name of the property
1017  * @errp: returns an error if this function fails
1018  *
1019  * Returns: the value of the property, converted to a C string, or NULL if
1020  * an error occurs (including when the property value is not a string).
1021  * The caller should free the string.
1022  */
1023 char *object_property_get_str(Object *obj, const char *name,
1024                               Error **errp);
1025 
1026 /**
1027  * object_property_set_link:
1028  * @value: the value to be written to the property
1029  * @name: the name of the property
1030  * @errp: returns an error if this function fails
1031  *
1032  * Writes an object's canonical path to a property.
1033  */
1034 void object_property_set_link(Object *obj, Object *value,
1035                               const char *name, Error **errp);
1036 
1037 /**
1038  * object_property_get_link:
1039  * @obj: the object
1040  * @name: the name of the property
1041  * @errp: returns an error if this function fails
1042  *
1043  * Returns: the value of the property, resolved from a path to an Object,
1044  * or NULL if an error occurs (including when the property value is not a
1045  * string or not a valid object path).
1046  */
1047 Object *object_property_get_link(Object *obj, const char *name,
1048                                  Error **errp);
1049 
1050 /**
1051  * object_property_set_bool:
1052  * @value: the value to be written to the property
1053  * @name: the name of the property
1054  * @errp: returns an error if this function fails
1055  *
1056  * Writes a bool value to a property.
1057  */
1058 void object_property_set_bool(Object *obj, bool value,
1059                               const char *name, Error **errp);
1060 
1061 /**
1062  * object_property_get_bool:
1063  * @obj: the object
1064  * @name: the name of the property
1065  * @errp: returns an error if this function fails
1066  *
1067  * Returns: the value of the property, converted to a boolean, or NULL if
1068  * an error occurs (including when the property value is not a bool).
1069  */
1070 bool object_property_get_bool(Object *obj, const char *name,
1071                               Error **errp);
1072 
1073 /**
1074  * object_property_set_int:
1075  * @value: the value to be written to the property
1076  * @name: the name of the property
1077  * @errp: returns an error if this function fails
1078  *
1079  * Writes an integer value to a property.
1080  */
1081 void object_property_set_int(Object *obj, int64_t value,
1082                              const char *name, Error **errp);
1083 
1084 /**
1085  * object_property_get_int:
1086  * @obj: the object
1087  * @name: the name of the property
1088  * @errp: returns an error if this function fails
1089  *
1090  * Returns: the value of the property, converted to an integer, or negative if
1091  * an error occurs (including when the property value is not an integer).
1092  */
1093 int64_t object_property_get_int(Object *obj, const char *name,
1094                                 Error **errp);
1095 
1096 /**
1097  * object_property_set_uint:
1098  * @value: the value to be written to the property
1099  * @name: the name of the property
1100  * @errp: returns an error if this function fails
1101  *
1102  * Writes an unsigned integer value to a property.
1103  */
1104 void object_property_set_uint(Object *obj, uint64_t value,
1105                               const char *name, Error **errp);
1106 
1107 /**
1108  * object_property_get_uint:
1109  * @obj: the object
1110  * @name: the name of the property
1111  * @errp: returns an error if this function fails
1112  *
1113  * Returns: the value of the property, converted to an unsigned integer, or 0
1114  * an error occurs (including when the property value is not an integer).
1115  */
1116 uint64_t object_property_get_uint(Object *obj, const char *name,
1117                                   Error **errp);
1118 
1119 /**
1120  * object_property_get_enum:
1121  * @obj: the object
1122  * @name: the name of the property
1123  * @typename: the name of the enum data type
1124  * @errp: returns an error if this function fails
1125  *
1126  * Returns: the value of the property, converted to an integer, or
1127  * undefined if an error occurs (including when the property value is not
1128  * an enum).
1129  */
1130 int object_property_get_enum(Object *obj, const char *name,
1131                              const char *typename, Error **errp);
1132 
1133 /**
1134  * object_property_get_uint16List:
1135  * @obj: the object
1136  * @name: the name of the property
1137  * @list: the returned int list
1138  * @errp: returns an error if this function fails
1139  *
1140  * Returns: the value of the property, converted to integers, or
1141  * undefined if an error occurs (including when the property value is not
1142  * an list of integers).
1143  */
1144 void object_property_get_uint16List(Object *obj, const char *name,
1145                                     uint16List **list, Error **errp);
1146 
1147 /**
1148  * object_property_set:
1149  * @obj: the object
1150  * @v: the visitor that will be used to write the property value.  This should
1151  *   be an Input visitor and the data will be first read with @name as the
1152  *   name and then written as the property value.
1153  * @name: the name of the property
1154  * @errp: returns an error if this function fails
1155  *
1156  * Writes a property to a object.
1157  */
1158 void object_property_set(Object *obj, Visitor *v, const char *name,
1159                          Error **errp);
1160 
1161 /**
1162  * object_property_parse:
1163  * @obj: the object
1164  * @string: the string that will be used to parse the property value.
1165  * @name: the name of the property
1166  * @errp: returns an error if this function fails
1167  *
1168  * Parses a string and writes the result into a property of an object.
1169  */
1170 void object_property_parse(Object *obj, const char *string,
1171                            const char *name, Error **errp);
1172 
1173 /**
1174  * object_property_print:
1175  * @obj: the object
1176  * @name: the name of the property
1177  * @human: if true, print for human consumption
1178  * @errp: returns an error if this function fails
1179  *
1180  * Returns a string representation of the value of the property.  The
1181  * caller shall free the string.
1182  */
1183 char *object_property_print(Object *obj, const char *name, bool human,
1184                             Error **errp);
1185 
1186 /**
1187  * object_property_get_type:
1188  * @obj: the object
1189  * @name: the name of the property
1190  * @errp: returns an error if this function fails
1191  *
1192  * Returns:  The type name of the property.
1193  */
1194 const char *object_property_get_type(Object *obj, const char *name,
1195                                      Error **errp);
1196 
1197 /**
1198  * object_get_root:
1199  *
1200  * Returns: the root object of the composition tree
1201  */
1202 Object *object_get_root(void);
1203 
1204 
1205 /**
1206  * object_get_objects_root:
1207  *
1208  * Get the container object that holds user created
1209  * object instances. This is the object at path
1210  * "/objects"
1211  *
1212  * Returns: the user object container
1213  */
1214 Object *object_get_objects_root(void);
1215 
1216 /**
1217  * object_get_internal_root:
1218  *
1219  * Get the container object that holds internally used object
1220  * instances.  Any object which is put into this container must not be
1221  * user visible, and it will not be exposed in the QOM tree.
1222  *
1223  * Returns: the internal object container
1224  */
1225 Object *object_get_internal_root(void);
1226 
1227 /**
1228  * object_get_canonical_path_component:
1229  *
1230  * Returns: The final component in the object's canonical path.  The canonical
1231  * path is the path within the composition tree starting from the root.
1232  */
1233 gchar *object_get_canonical_path_component(Object *obj);
1234 
1235 /**
1236  * object_get_canonical_path:
1237  *
1238  * Returns: The canonical path for a object.  This is the path within the
1239  * composition tree starting from the root.
1240  */
1241 gchar *object_get_canonical_path(Object *obj);
1242 
1243 /**
1244  * object_resolve_path:
1245  * @path: the path to resolve
1246  * @ambiguous: returns true if the path resolution failed because of an
1247  *   ambiguous match
1248  *
1249  * There are two types of supported paths--absolute paths and partial paths.
1250  *
1251  * Absolute paths are derived from the root object and can follow child<> or
1252  * link<> properties.  Since they can follow link<> properties, they can be
1253  * arbitrarily long.  Absolute paths look like absolute filenames and are
1254  * prefixed with a leading slash.
1255  *
1256  * Partial paths look like relative filenames.  They do not begin with a
1257  * prefix.  The matching rules for partial paths are subtle but designed to make
1258  * specifying objects easy.  At each level of the composition tree, the partial
1259  * path is matched as an absolute path.  The first match is not returned.  At
1260  * least two matches are searched for.  A successful result is only returned if
1261  * only one match is found.  If more than one match is found, a flag is
1262  * returned to indicate that the match was ambiguous.
1263  *
1264  * Returns: The matched object or NULL on path lookup failure.
1265  */
1266 Object *object_resolve_path(const char *path, bool *ambiguous);
1267 
1268 /**
1269  * object_resolve_path_type:
1270  * @path: the path to resolve
1271  * @typename: the type to look for.
1272  * @ambiguous: returns true if the path resolution failed because of an
1273  *   ambiguous match
1274  *
1275  * This is similar to object_resolve_path.  However, when looking for a
1276  * partial path only matches that implement the given type are considered.
1277  * This restricts the search and avoids spuriously flagging matches as
1278  * ambiguous.
1279  *
1280  * For both partial and absolute paths, the return value goes through
1281  * a dynamic cast to @typename.  This is important if either the link,
1282  * or the typename itself are of interface types.
1283  *
1284  * Returns: The matched object or NULL on path lookup failure.
1285  */
1286 Object *object_resolve_path_type(const char *path, const char *typename,
1287                                  bool *ambiguous);
1288 
1289 /**
1290  * object_resolve_path_component:
1291  * @parent: the object in which to resolve the path
1292  * @part: the component to resolve.
1293  *
1294  * This is similar to object_resolve_path with an absolute path, but it
1295  * only resolves one element (@part) and takes the others from @parent.
1296  *
1297  * Returns: The resolved object or NULL on path lookup failure.
1298  */
1299 Object *object_resolve_path_component(Object *parent, const gchar *part);
1300 
1301 /**
1302  * object_property_add_child:
1303  * @obj: the object to add a property to
1304  * @name: the name of the property
1305  * @child: the child object
1306  * @errp: if an error occurs, a pointer to an area to store the area
1307  *
1308  * Child properties form the composition tree.  All objects need to be a child
1309  * of another object.  Objects can only be a child of one object.
1310  *
1311  * There is no way for a child to determine what its parent is.  It is not
1312  * a bidirectional relationship.  This is by design.
1313  *
1314  * The value of a child property as a C string will be the child object's
1315  * canonical path. It can be retrieved using object_property_get_str().
1316  * The child object itself can be retrieved using object_property_get_link().
1317  */
1318 void object_property_add_child(Object *obj, const char *name,
1319                                Object *child, Error **errp);
1320 
1321 typedef enum {
1322     /* Unref the link pointer when the property is deleted */
1323     OBJ_PROP_LINK_UNREF_ON_RELEASE = 0x1,
1324 } ObjectPropertyLinkFlags;
1325 
1326 /**
1327  * object_property_allow_set_link:
1328  *
1329  * The default implementation of the object_property_add_link() check()
1330  * callback function.  It allows the link property to be set and never returns
1331  * an error.
1332  */
1333 void object_property_allow_set_link(const Object *, const char *,
1334                                     Object *, Error **);
1335 
1336 /**
1337  * object_property_add_link:
1338  * @obj: the object to add a property to
1339  * @name: the name of the property
1340  * @type: the qobj type of the link
1341  * @child: a pointer to where the link object reference is stored
1342  * @check: callback to veto setting or NULL if the property is read-only
1343  * @flags: additional options for the link
1344  * @errp: if an error occurs, a pointer to an area to store the area
1345  *
1346  * Links establish relationships between objects.  Links are unidirectional
1347  * although two links can be combined to form a bidirectional relationship
1348  * between objects.
1349  *
1350  * Links form the graph in the object model.
1351  *
1352  * The <code>@check()</code> callback is invoked when
1353  * object_property_set_link() is called and can raise an error to prevent the
1354  * link being set.  If <code>@check</code> is NULL, the property is read-only
1355  * and cannot be set.
1356  *
1357  * Ownership of the pointer that @child points to is transferred to the
1358  * link property.  The reference count for <code>*@child</code> is
1359  * managed by the property from after the function returns till the
1360  * property is deleted with object_property_del().  If the
1361  * <code>@flags</code> <code>OBJ_PROP_LINK_UNREF_ON_RELEASE</code> bit is set,
1362  * the reference count is decremented when the property is deleted.
1363  */
1364 void object_property_add_link(Object *obj, const char *name,
1365                               const char *type, Object **child,
1366                               void (*check)(const Object *obj, const char *name,
1367                                             Object *val, Error **errp),
1368                               ObjectPropertyLinkFlags flags,
1369                               Error **errp);
1370 
1371 /**
1372  * object_property_add_str:
1373  * @obj: the object to add a property to
1374  * @name: the name of the property
1375  * @get: the getter or NULL if the property is write-only.  This function must
1376  *   return a string to be freed by g_free().
1377  * @set: the setter or NULL if the property is read-only
1378  * @errp: if an error occurs, a pointer to an area to store the error
1379  *
1380  * Add a string property using getters/setters.  This function will add a
1381  * property of type 'string'.
1382  */
1383 void object_property_add_str(Object *obj, const char *name,
1384                              char *(*get)(Object *, Error **),
1385                              void (*set)(Object *, const char *, Error **),
1386                              Error **errp);
1387 
1388 void object_class_property_add_str(ObjectClass *klass, const char *name,
1389                                    char *(*get)(Object *, Error **),
1390                                    void (*set)(Object *, const char *,
1391                                                Error **),
1392                                    Error **errp);
1393 
1394 /**
1395  * object_property_add_bool:
1396  * @obj: the object to add a property to
1397  * @name: the name of the property
1398  * @get: the getter or NULL if the property is write-only.
1399  * @set: the setter or NULL if the property is read-only
1400  * @errp: if an error occurs, a pointer to an area to store the error
1401  *
1402  * Add a bool property using getters/setters.  This function will add a
1403  * property of type 'bool'.
1404  */
1405 void object_property_add_bool(Object *obj, const char *name,
1406                               bool (*get)(Object *, Error **),
1407                               void (*set)(Object *, bool, Error **),
1408                               Error **errp);
1409 
1410 void object_class_property_add_bool(ObjectClass *klass, const char *name,
1411                                     bool (*get)(Object *, Error **),
1412                                     void (*set)(Object *, bool, Error **),
1413                                     Error **errp);
1414 
1415 /**
1416  * object_property_add_enum:
1417  * @obj: the object to add a property to
1418  * @name: the name of the property
1419  * @typename: the name of the enum data type
1420  * @get: the getter or %NULL if the property is write-only.
1421  * @set: the setter or %NULL if the property is read-only
1422  * @errp: if an error occurs, a pointer to an area to store the error
1423  *
1424  * Add an enum property using getters/setters.  This function will add a
1425  * property of type '@typename'.
1426  */
1427 void object_property_add_enum(Object *obj, const char *name,
1428                               const char *typename,
1429                               const QEnumLookup *lookup,
1430                               int (*get)(Object *, Error **),
1431                               void (*set)(Object *, int, Error **),
1432                               Error **errp);
1433 
1434 void object_class_property_add_enum(ObjectClass *klass, const char *name,
1435                                     const char *typename,
1436                                     const QEnumLookup *lookup,
1437                                     int (*get)(Object *, Error **),
1438                                     void (*set)(Object *, int, Error **),
1439                                     Error **errp);
1440 
1441 /**
1442  * object_property_add_tm:
1443  * @obj: the object to add a property to
1444  * @name: the name of the property
1445  * @get: the getter or NULL if the property is write-only.
1446  * @errp: if an error occurs, a pointer to an area to store the error
1447  *
1448  * Add a read-only struct tm valued property using a getter function.
1449  * This function will add a property of type 'struct tm'.
1450  */
1451 void object_property_add_tm(Object *obj, const char *name,
1452                             void (*get)(Object *, struct tm *, Error **),
1453                             Error **errp);
1454 
1455 void object_class_property_add_tm(ObjectClass *klass, const char *name,
1456                                   void (*get)(Object *, struct tm *, Error **),
1457                                   Error **errp);
1458 
1459 /**
1460  * object_property_add_uint8_ptr:
1461  * @obj: the object to add a property to
1462  * @name: the name of the property
1463  * @v: pointer to value
1464  * @errp: if an error occurs, a pointer to an area to store the error
1465  *
1466  * Add an integer property in memory.  This function will add a
1467  * property of type 'uint8'.
1468  */
1469 void object_property_add_uint8_ptr(Object *obj, const char *name,
1470                                    const uint8_t *v, Error **errp);
1471 void object_class_property_add_uint8_ptr(ObjectClass *klass, const char *name,
1472                                          const uint8_t *v, Error **errp);
1473 
1474 /**
1475  * object_property_add_uint16_ptr:
1476  * @obj: the object to add a property to
1477  * @name: the name of the property
1478  * @v: pointer to value
1479  * @errp: if an error occurs, a pointer to an area to store the error
1480  *
1481  * Add an integer property in memory.  This function will add a
1482  * property of type 'uint16'.
1483  */
1484 void object_property_add_uint16_ptr(Object *obj, const char *name,
1485                                     const uint16_t *v, Error **errp);
1486 void object_class_property_add_uint16_ptr(ObjectClass *klass, const char *name,
1487                                           const uint16_t *v, Error **errp);
1488 
1489 /**
1490  * object_property_add_uint32_ptr:
1491  * @obj: the object to add a property to
1492  * @name: the name of the property
1493  * @v: pointer to value
1494  * @errp: if an error occurs, a pointer to an area to store the error
1495  *
1496  * Add an integer property in memory.  This function will add a
1497  * property of type 'uint32'.
1498  */
1499 void object_property_add_uint32_ptr(Object *obj, const char *name,
1500                                     const uint32_t *v, Error **errp);
1501 void object_class_property_add_uint32_ptr(ObjectClass *klass, const char *name,
1502                                           const uint32_t *v, Error **errp);
1503 
1504 /**
1505  * object_property_add_uint64_ptr:
1506  * @obj: the object to add a property to
1507  * @name: the name of the property
1508  * @v: pointer to value
1509  * @errp: if an error occurs, a pointer to an area to store the error
1510  *
1511  * Add an integer property in memory.  This function will add a
1512  * property of type 'uint64'.
1513  */
1514 void object_property_add_uint64_ptr(Object *obj, const char *name,
1515                                     const uint64_t *v, Error **Errp);
1516 void object_class_property_add_uint64_ptr(ObjectClass *klass, const char *name,
1517                                           const uint64_t *v, Error **Errp);
1518 
1519 /**
1520  * object_property_add_alias:
1521  * @obj: the object to add a property to
1522  * @name: the name of the property
1523  * @target_obj: the object to forward property access to
1524  * @target_name: the name of the property on the forwarded object
1525  * @errp: if an error occurs, a pointer to an area to store the error
1526  *
1527  * Add an alias for a property on an object.  This function will add a property
1528  * of the same type as the forwarded property.
1529  *
1530  * The caller must ensure that <code>@target_obj</code> stays alive as long as
1531  * this property exists.  In the case of a child object or an alias on the same
1532  * object this will be the case.  For aliases to other objects the caller is
1533  * responsible for taking a reference.
1534  */
1535 void object_property_add_alias(Object *obj, const char *name,
1536                                Object *target_obj, const char *target_name,
1537                                Error **errp);
1538 
1539 /**
1540  * object_property_add_const_link:
1541  * @obj: the object to add a property to
1542  * @name: the name of the property
1543  * @target: the object to be referred by the link
1544  * @errp: if an error occurs, a pointer to an area to store the error
1545  *
1546  * Add an unmodifiable link for a property on an object.  This function will
1547  * add a property of type link<TYPE> where TYPE is the type of @target.
1548  *
1549  * The caller must ensure that @target stays alive as long as
1550  * this property exists.  In the case @target is a child of @obj,
1551  * this will be the case.  Otherwise, the caller is responsible for
1552  * taking a reference.
1553  */
1554 void object_property_add_const_link(Object *obj, const char *name,
1555                                     Object *target, Error **errp);
1556 
1557 /**
1558  * object_property_set_description:
1559  * @obj: the object owning the property
1560  * @name: the name of the property
1561  * @description: the description of the property on the object
1562  * @errp: if an error occurs, a pointer to an area to store the error
1563  *
1564  * Set an object property's description.
1565  *
1566  */
1567 void object_property_set_description(Object *obj, const char *name,
1568                                      const char *description, Error **errp);
1569 void object_class_property_set_description(ObjectClass *klass, const char *name,
1570                                            const char *description,
1571                                            Error **errp);
1572 
1573 /**
1574  * object_child_foreach:
1575  * @obj: the object whose children will be navigated
1576  * @fn: the iterator function to be called
1577  * @opaque: an opaque value that will be passed to the iterator
1578  *
1579  * Call @fn passing each child of @obj and @opaque to it, until @fn returns
1580  * non-zero.
1581  *
1582  * It is forbidden to add or remove children from @obj from the @fn
1583  * callback.
1584  *
1585  * Returns: The last value returned by @fn, or 0 if there is no child.
1586  */
1587 int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
1588                          void *opaque);
1589 
1590 /**
1591  * object_child_foreach_recursive:
1592  * @obj: the object whose children will be navigated
1593  * @fn: the iterator function to be called
1594  * @opaque: an opaque value that will be passed to the iterator
1595  *
1596  * Call @fn passing each child of @obj and @opaque to it, until @fn returns
1597  * non-zero. Calls recursively, all child nodes of @obj will also be passed
1598  * all the way down to the leaf nodes of the tree. Depth first ordering.
1599  *
1600  * It is forbidden to add or remove children from @obj (or its
1601  * child nodes) from the @fn callback.
1602  *
1603  * Returns: The last value returned by @fn, or 0 if there is no child.
1604  */
1605 int object_child_foreach_recursive(Object *obj,
1606                                    int (*fn)(Object *child, void *opaque),
1607                                    void *opaque);
1608 /**
1609  * container_get:
1610  * @root: root of the #path, e.g., object_get_root()
1611  * @path: path to the container
1612  *
1613  * Return a container object whose path is @path.  Create more containers
1614  * along the path if necessary.
1615  *
1616  * Returns: the container object.
1617  */
1618 Object *container_get(Object *root, const char *path);
1619 
1620 /**
1621  * object_type_get_instance_size:
1622  * @typename: Name of the Type whose instance_size is required
1623  *
1624  * Returns the instance_size of the given @typename.
1625  */
1626 size_t object_type_get_instance_size(const char *typename);
1627 #endif
1628