qemu/include/qom/object.h
<<
>>
Prefs
   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/qapi-builtin-types.h"
  18#include "qemu/queue.h"
  19#include "qemu/module.h"
  20
  21struct TypeImpl;
  22typedef struct TypeImpl *Type;
  23
  24typedef struct Object Object;
  25
  26typedef struct TypeInfo TypeInfo;
  27
  28typedef struct InterfaceClass InterfaceClass;
  29typedef 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 * Alternatively several static types could be registered using helper macro
  83 * DEFINE_TYPES()
  84 *
  85 * <example>
  86 *   <programlisting>
  87 * static const TypeInfo device_types_info[] = {
  88 *     {
  89 *         .name = TYPE_MY_DEVICE_A,
  90 *         .parent = TYPE_DEVICE,
  91 *         .instance_size = sizeof(MyDeviceA),
  92 *     },
  93 *     {
  94 *         .name = TYPE_MY_DEVICE_B,
  95 *         .parent = TYPE_DEVICE,
  96 *         .instance_size = sizeof(MyDeviceB),
  97 *     },
  98 * };
  99 *
 100 * DEFINE_TYPES(device_types_info)
 101 *   </programlisting>
 102 * </example>
 103 *
 104 * Every type has an #ObjectClass associated with it.  #ObjectClass derivatives
 105 * are instantiated dynamically but there is only ever one instance for any
 106 * given type.  The #ObjectClass typically holds a table of function pointers
 107 * for the virtual methods implemented by this type.
 108 *
 109 * Using object_new(), a new #Object derivative will be instantiated.  You can
 110 * cast an #Object to a subclass (or base-class) type using
 111 * object_dynamic_cast().  You typically want to define macro wrappers around
 112 * OBJECT_CHECK() and OBJECT_CLASS_CHECK() to make it easier to convert to a
 113 * specific type:
 114 *
 115 * <example>
 116 *   <title>Typecasting macros</title>
 117 *   <programlisting>
 118 *    #define MY_DEVICE_GET_CLASS(obj) \
 119 *       OBJECT_GET_CLASS(MyDeviceClass, obj, TYPE_MY_DEVICE)
 120 *    #define MY_DEVICE_CLASS(klass) \
 121 *       OBJECT_CLASS_CHECK(MyDeviceClass, klass, TYPE_MY_DEVICE)
 122 *    #define MY_DEVICE(obj) \
 123 *       OBJECT_CHECK(MyDevice, obj, TYPE_MY_DEVICE)
 124 *   </programlisting>
 125 * </example>
 126 *
 127 * # Class Initialization #
 128 *
 129 * Before an object is initialized, the class for the object must be
 130 * initialized.  There is only one class object for all instance objects
 131 * that is created lazily.
 132 *
 133 * Classes are initialized by first initializing any parent classes (if
 134 * necessary).  After the parent class object has initialized, it will be
 135 * copied into the current class object and any additional storage in the
 136 * class object is zero filled.
 137 *
 138 * The effect of this is that classes automatically inherit any virtual
 139 * function pointers that the parent class has already initialized.  All
 140 * other fields will be zero filled.
 141 *
 142 * Once all of the parent classes have been initialized, #TypeInfo::class_init
 143 * is called to let the class being instantiated provide default initialize for
 144 * its virtual functions.  Here is how the above example might be modified
 145 * to introduce an overridden virtual function:
 146 *
 147 * <example>
 148 *   <title>Overriding a virtual function</title>
 149 *   <programlisting>
 150 * #include "qdev.h"
 151 *
 152 * void my_device_class_init(ObjectClass *klass, void *class_data)
 153 * {
 154 *     DeviceClass *dc = DEVICE_CLASS(klass);
 155 *     dc->reset = my_device_reset;
 156 * }
 157 *
 158 * static const TypeInfo my_device_info = {
 159 *     .name = TYPE_MY_DEVICE,
 160 *     .parent = TYPE_DEVICE,
 161 *     .instance_size = sizeof(MyDevice),
 162 *     .class_init = my_device_class_init,
 163 * };
 164 *   </programlisting>
 165 * </example>
 166 *
 167 * Introducing new virtual methods requires a class to define its own
 168 * struct and to add a .class_size member to the #TypeInfo.  Each method
 169 * will also have a wrapper function to call it easily:
 170 *
 171 * <example>
 172 *   <title>Defining an abstract class</title>
 173 *   <programlisting>
 174 * #include "qdev.h"
 175 *
 176 * typedef struct MyDeviceClass
 177 * {
 178 *     DeviceClass parent;
 179 *
 180 *     void (*frobnicate) (MyDevice *obj);
 181 * } MyDeviceClass;
 182 *
 183 * static const TypeInfo my_device_info = {
 184 *     .name = TYPE_MY_DEVICE,
 185 *     .parent = TYPE_DEVICE,
 186 *     .instance_size = sizeof(MyDevice),
 187 *     .abstract = true, // or set a default in my_device_class_init
 188 *     .class_size = sizeof(MyDeviceClass),
 189 * };
 190 *
 191 * void my_device_frobnicate(MyDevice *obj)
 192 * {
 193 *     MyDeviceClass *klass = MY_DEVICE_GET_CLASS(obj);
 194 *
 195 *     klass->frobnicate(obj);
 196 * }
 197 *   </programlisting>
 198 * </example>
 199 *
 200 * # Interfaces #
 201 *
 202 * Interfaces allow a limited form of multiple inheritance.  Instances are
 203 * similar to normal types except for the fact that are only defined by
 204 * their classes and never carry any state.  You can dynamically cast an object
 205 * to one of its #Interface types and vice versa.
 206 *
 207 * # Methods #
 208 *
 209 * A <emphasis>method</emphasis> is a function within the namespace scope of
 210 * a class. It usually operates on the object instance by passing it as a
 211 * strongly-typed first argument.
 212 * If it does not operate on an object instance, it is dubbed
 213 * <emphasis>class method</emphasis>.
 214 *
 215 * Methods cannot be overloaded. That is, the #ObjectClass and method name
 216 * uniquely identity the function to be called; the signature does not vary
 217 * except for trailing varargs.
 218 *
 219 * Methods are always <emphasis>virtual</emphasis>. Overriding a method in
 220 * #TypeInfo.class_init of a subclass leads to any user of the class obtained
 221 * via OBJECT_GET_CLASS() accessing the overridden function.
 222 * The original function is not automatically invoked. It is the responsibility
 223 * of the overriding class to determine whether and when to invoke the method
 224 * being overridden.
 225 *
 226 * To invoke the method being overridden, the preferred solution is to store
 227 * the original value in the overriding class before overriding the method.
 228 * This corresponds to |[ {super,base}.method(...) ]| in Java and C#
 229 * respectively; this frees the overriding class from hardcoding its parent
 230 * class, which someone might choose to change at some point.
 231 *
 232 * <example>
 233 *   <title>Overriding a virtual method</title>
 234 *   <programlisting>
 235 * typedef struct MyState MyState;
 236 *
 237 * typedef void (*MyDoSomething)(MyState *obj);
 238 *
 239 * typedef struct MyClass {
 240 *     ObjectClass parent_class;
 241 *
 242 *     MyDoSomething do_something;
 243 * } MyClass;
 244 *
 245 * static void my_do_something(MyState *obj)
 246 * {
 247 *     // do something
 248 * }
 249 *
 250 * static void my_class_init(ObjectClass *oc, void *data)
 251 * {
 252 *     MyClass *mc = MY_CLASS(oc);
 253 *
 254 *     mc->do_something = my_do_something;
 255 * }
 256 *
 257 * static const TypeInfo my_type_info = {
 258 *     .name = TYPE_MY,
 259 *     .parent = TYPE_OBJECT,
 260 *     .instance_size = sizeof(MyState),
 261 *     .class_size = sizeof(MyClass),
 262 *     .class_init = my_class_init,
 263 * };
 264 *
 265 * typedef struct DerivedClass {
 266 *     MyClass parent_class;
 267 *
 268 *     MyDoSomething parent_do_something;
 269 * } DerivedClass;
 270 *
 271 * static void derived_do_something(MyState *obj)
 272 * {
 273 *     DerivedClass *dc = DERIVED_GET_CLASS(obj);
 274 *
 275 *     // do something here
 276 *     dc->parent_do_something(obj);
 277 *     // do something else here
 278 * }
 279 *
 280 * static void derived_class_init(ObjectClass *oc, void *data)
 281 * {
 282 *     MyClass *mc = MY_CLASS(oc);
 283 *     DerivedClass *dc = DERIVED_CLASS(oc);
 284 *
 285 *     dc->parent_do_something = mc->do_something;
 286 *     mc->do_something = derived_do_something;
 287 * }
 288 *
 289 * static const TypeInfo derived_type_info = {
 290 *     .name = TYPE_DERIVED,
 291 *     .parent = TYPE_MY,
 292 *     .class_size = sizeof(DerivedClass),
 293 *     .class_init = derived_class_init,
 294 * };
 295 *   </programlisting>
 296 * </example>
 297 *
 298 * Alternatively, object_class_by_name() can be used to obtain the class and
 299 * its non-overridden methods for a specific type. This would correspond to
 300 * |[ MyClass::method(...) ]| in C++.
 301 *
 302 * The first example of such a QOM method was #CPUClass.reset,
 303 * another example is #DeviceClass.realize.
 304 */
 305
 306
 307/**
 308 * ObjectPropertyAccessor:
 309 * @obj: the object that owns the property
 310 * @v: the visitor that contains the property data
 311 * @name: the name of the property
 312 * @opaque: the object property opaque
 313 * @errp: a pointer to an Error that is filled if getting/setting fails.
 314 *
 315 * Called when trying to get/set a property.
 316 */
 317typedef void (ObjectPropertyAccessor)(Object *obj,
 318                                      Visitor *v,
 319                                      const char *name,
 320                                      void *opaque,
 321                                      Error **errp);
 322
 323/**
 324 * ObjectPropertyResolve:
 325 * @obj: the object that owns the property
 326 * @opaque: the opaque registered with the property
 327 * @part: the name of the property
 328 *
 329 * Resolves the #Object corresponding to property @part.
 330 *
 331 * The returned object can also be used as a starting point
 332 * to resolve a relative path starting with "@part".
 333 *
 334 * Returns: If @path is the path that led to @obj, the function
 335 * returns the #Object corresponding to "@path/@part".
 336 * If "@path/@part" is not a valid object path, it returns #NULL.
 337 */
 338typedef Object *(ObjectPropertyResolve)(Object *obj,
 339                                        void *opaque,
 340                                        const char *part);
 341
 342/**
 343 * ObjectPropertyRelease:
 344 * @obj: the object that owns the property
 345 * @name: the name of the property
 346 * @opaque: the opaque registered with the property
 347 *
 348 * Called when a property is removed from a object.
 349 */
 350typedef void (ObjectPropertyRelease)(Object *obj,
 351                                     const char *name,
 352                                     void *opaque);
 353
 354typedef struct ObjectProperty
 355{
 356    gchar *name;
 357    gchar *type;
 358    gchar *description;
 359    ObjectPropertyAccessor *get;
 360    ObjectPropertyAccessor *set;
 361    ObjectPropertyResolve *resolve;
 362    ObjectPropertyRelease *release;
 363    void *opaque;
 364} ObjectProperty;
 365
 366/**
 367 * ObjectUnparent:
 368 * @obj: the object that is being removed from the composition tree
 369 *
 370 * Called when an object is being removed from the QOM composition tree.
 371 * The function should remove any backlinks from children objects to @obj.
 372 */
 373typedef void (ObjectUnparent)(Object *obj);
 374
 375/**
 376 * ObjectFree:
 377 * @obj: the object being freed
 378 *
 379 * Called when an object's last reference is removed.
 380 */
 381typedef void (ObjectFree)(void *obj);
 382
 383#define OBJECT_CLASS_CAST_CACHE 4
 384
 385/**
 386 * ObjectClass:
 387 *
 388 * The base for all classes.  The only thing that #ObjectClass contains is an
 389 * integer type handle.
 390 */
 391struct ObjectClass
 392{
 393    /*< private >*/
 394    Type type;
 395    GSList *interfaces;
 396
 397    const char *object_cast_cache[OBJECT_CLASS_CAST_CACHE];
 398    const char *class_cast_cache[OBJECT_CLASS_CAST_CACHE];
 399
 400    ObjectUnparent *unparent;
 401
 402    GHashTable *properties;
 403};
 404
 405/**
 406 * Object:
 407 *
 408 * The base for all objects.  The first member of this object is a pointer to
 409 * a #ObjectClass.  Since C guarantees that the first member of a structure
 410 * always begins at byte 0 of that structure, as long as any sub-object places
 411 * its parent as the first member, we can cast directly to a #Object.
 412 *
 413 * As a result, #Object contains a reference to the objects type as its
 414 * first member.  This allows identification of the real type of the object at
 415 * run time.
 416 */
 417struct Object
 418{
 419    /*< private >*/
 420    ObjectClass *class;
 421    ObjectFree *free;
 422    GHashTable *properties;
 423    uint32_t ref;
 424    Object *parent;
 425};
 426
 427/**
 428 * TypeInfo:
 429 * @name: The name of the type.
 430 * @parent: The name of the parent type.
 431 * @instance_size: The size of the object (derivative of #Object).  If
 432 *   @instance_size is 0, then the size of the object will be the size of the
 433 *   parent object.
 434 * @instance_init: This function is called to initialize an object.  The parent
 435 *   class will have already been initialized so the type is only responsible
 436 *   for initializing its own members.
 437 * @instance_post_init: This function is called to finish initialization of
 438 *   an object, after all @instance_init functions were called.
 439 * @instance_finalize: This function is called during object destruction.  This
 440 *   is called before the parent @instance_finalize function has been called.
 441 *   An object should only free the members that are unique to its type in this
 442 *   function.
 443 * @abstract: If this field is true, then the class is considered abstract and
 444 *   cannot be directly instantiated.
 445 * @class_size: The size of the class object (derivative of #ObjectClass)
 446 *   for this object.  If @class_size is 0, then the size of the class will be
 447 *   assumed to be the size of the parent class.  This allows a type to avoid
 448 *   implementing an explicit class type if they are not adding additional
 449 *   virtual functions.
 450 * @class_init: This function is called after all parent class initialization
 451 *   has occurred to allow a class to set its default virtual method pointers.
 452 *   This is also the function to use to override virtual methods from a parent
 453 *   class.
 454 * @class_base_init: This function is called for all base classes after all
 455 *   parent class initialization has occurred, but before the class itself
 456 *   is initialized.  This is the function to use to undo the effects of
 457 *   memcpy from the parent class to the descendants.
 458 * @class_data: Data to pass to the @class_init,
 459 *   @class_base_init. This can be useful when building dynamic
 460 *   classes.
 461 * @interfaces: The list of interfaces associated with this type.  This
 462 *   should point to a static array that's terminated with a zero filled
 463 *   element.
 464 */
 465struct TypeInfo
 466{
 467    const char *name;
 468    const char *parent;
 469
 470    size_t instance_size;
 471    void (*instance_init)(Object *obj);
 472    void (*instance_post_init)(Object *obj);
 473    void (*instance_finalize)(Object *obj);
 474
 475    bool abstract;
 476    size_t class_size;
 477
 478    void (*class_init)(ObjectClass *klass, void *data);
 479    void (*class_base_init)(ObjectClass *klass, void *data);
 480    void *class_data;
 481
 482    InterfaceInfo *interfaces;
 483};
 484
 485/**
 486 * OBJECT:
 487 * @obj: A derivative of #Object
 488 *
 489 * Converts an object to a #Object.  Since all objects are #Objects,
 490 * this function will always succeed.
 491 */
 492#define OBJECT(obj) \
 493    ((Object *)(obj))
 494
 495/**
 496 * OBJECT_CLASS:
 497 * @class: A derivative of #ObjectClass.
 498 *
 499 * Converts a class to an #ObjectClass.  Since all objects are #Objects,
 500 * this function will always succeed.
 501 */
 502#define OBJECT_CLASS(class) \
 503    ((ObjectClass *)(class))
 504
 505/**
 506 * OBJECT_CHECK:
 507 * @type: The C type to use for the return value.
 508 * @obj: A derivative of @type to cast.
 509 * @name: The QOM typename of @type
 510 *
 511 * A type safe version of @object_dynamic_cast_assert.  Typically each class
 512 * will define a macro based on this type to perform type safe dynamic_casts to
 513 * this object type.
 514 *
 515 * If an invalid object is passed to this function, a run time assert will be
 516 * generated.
 517 */
 518#define OBJECT_CHECK(type, obj, name) \
 519    ((type *)object_dynamic_cast_assert(OBJECT(obj), (name), \
 520                                        __FILE__, __LINE__, __func__))
 521
 522/**
 523 * OBJECT_CLASS_CHECK:
 524 * @class_type: The C type to use for the return value.
 525 * @class: A derivative class of @class_type to cast.
 526 * @name: the QOM typename of @class_type.
 527 *
 528 * A type safe version of @object_class_dynamic_cast_assert.  This macro is
 529 * typically wrapped by each type to perform type safe casts of a class to a
 530 * specific class type.
 531 */
 532#define OBJECT_CLASS_CHECK(class_type, class, name) \
 533    ((class_type *)object_class_dynamic_cast_assert(OBJECT_CLASS(class), (name), \
 534                                               __FILE__, __LINE__, __func__))
 535
 536/**
 537 * OBJECT_GET_CLASS:
 538 * @class: The C type to use for the return value.
 539 * @obj: The object to obtain the class for.
 540 * @name: The QOM typename of @obj.
 541 *
 542 * This function will return a specific class for a given object.  Its generally
 543 * used by each type to provide a type safe macro to get a specific class type
 544 * from an object.
 545 */
 546#define OBJECT_GET_CLASS(class, obj, name) \
 547    OBJECT_CLASS_CHECK(class, object_get_class(OBJECT(obj)), name)
 548
 549/**
 550 * InterfaceInfo:
 551 * @type: The name of the interface.
 552 *
 553 * The information associated with an interface.
 554 */
 555struct InterfaceInfo {
 556    const char *type;
 557};
 558
 559/**
 560 * InterfaceClass:
 561 * @parent_class: the base class
 562 *
 563 * The class for all interfaces.  Subclasses of this class should only add
 564 * virtual methods.
 565 */
 566struct InterfaceClass
 567{
 568    ObjectClass parent_class;
 569    /*< private >*/
 570    ObjectClass *concrete_class;
 571    Type interface_type;
 572};
 573
 574#define TYPE_INTERFACE "interface"
 575
 576/**
 577 * INTERFACE_CLASS:
 578 * @klass: class to cast from
 579 * Returns: An #InterfaceClass or raise an error if cast is invalid
 580 */
 581#define INTERFACE_CLASS(klass) \
 582    OBJECT_CLASS_CHECK(InterfaceClass, klass, TYPE_INTERFACE)
 583
 584/**
 585 * INTERFACE_CHECK:
 586 * @interface: the type to return
 587 * @obj: the object to convert to an interface
 588 * @name: the interface type name
 589 *
 590 * Returns: @obj casted to @interface if cast is valid, otherwise raise error.
 591 */
 592#define INTERFACE_CHECK(interface, obj, name) \
 593    ((interface *)object_dynamic_cast_assert(OBJECT((obj)), (name), \
 594                                             __FILE__, __LINE__, __func__))
 595
 596/**
 597 * object_new:
 598 * @typename: The name of the type of the object to instantiate.
 599 *
 600 * This function will initialize a new object using heap allocated memory.
 601 * The returned object has a reference count of 1, and will be freed when
 602 * the last reference is dropped.
 603 *
 604 * Returns: The newly allocated and instantiated object.
 605 */
 606Object *object_new(const char *typename);
 607
 608/**
 609 * object_new_with_props:
 610 * @typename:  The name of the type of the object to instantiate.
 611 * @parent: the parent object
 612 * @id: The unique ID of the object
 613 * @errp: pointer to error object
 614 * @...: list of property names and values
 615 *
 616 * This function will initialize a new object using heap allocated memory.
 617 * The returned object has a reference count of 1, and will be freed when
 618 * the last reference is dropped.
 619 *
 620 * The @id parameter will be used when registering the object as a
 621 * child of @parent in the composition tree.
 622 *
 623 * The variadic parameters are a list of pairs of (propname, propvalue)
 624 * strings. The propname of %NULL indicates the end of the property
 625 * list. If the object implements the user creatable interface, the
 626 * object will be marked complete once all the properties have been
 627 * processed.
 628 *
 629 * <example>
 630 *   <title>Creating an object with properties</title>
 631 *   <programlisting>
 632 *   Error *err = NULL;
 633 *   Object *obj;
 634 *
 635 *   obj = object_new_with_props(TYPE_MEMORY_BACKEND_FILE,
 636 *                               object_get_objects_root(),
 637 *                               "hostmem0",
 638 *                               &err,
 639 *                               "share", "yes",
 640 *                               "mem-path", "/dev/shm/somefile",
 641 *                               "prealloc", "yes",
 642 *                               "size", "1048576",
 643 *                               NULL);
 644 *
 645 *   if (!obj) {
 646 *     g_printerr("Cannot create memory backend: %s\n",
 647 *                error_get_pretty(err));
 648 *   }
 649 *   </programlisting>
 650 * </example>
 651 *
 652 * The returned object will have one stable reference maintained
 653 * for as long as it is present in the object hierarchy.
 654 *
 655 * Returns: The newly allocated, instantiated & initialized object.
 656 */
 657Object *object_new_with_props(const char *typename,
 658                              Object *parent,
 659                              const char *id,
 660                              Error **errp,
 661                              ...) QEMU_SENTINEL;
 662
 663/**
 664 * object_new_with_propv:
 665 * @typename:  The name of the type of the object to instantiate.
 666 * @parent: the parent object
 667 * @id: The unique ID of the object
 668 * @errp: pointer to error object
 669 * @vargs: list of property names and values
 670 *
 671 * See object_new_with_props() for documentation.
 672 */
 673Object *object_new_with_propv(const char *typename,
 674                              Object *parent,
 675                              const char *id,
 676                              Error **errp,
 677                              va_list vargs);
 678
 679void object_apply_global_props(Object *obj, const GPtrArray *props,
 680                               Error **errp);
 681void object_set_machine_compat_props(GPtrArray *compat_props);
 682void object_set_accelerator_compat_props(GPtrArray *compat_props);
 683void object_apply_compat_props(Object *obj);
 684
 685/**
 686 * object_set_props:
 687 * @obj: the object instance to set properties on
 688 * @errp: pointer to error object
 689 * @...: list of property names and values
 690 *
 691 * This function will set a list of properties on an existing object
 692 * instance.
 693 *
 694 * The variadic parameters are a list of pairs of (propname, propvalue)
 695 * strings. The propname of %NULL indicates the end of the property
 696 * list.
 697 *
 698 * <example>
 699 *   <title>Update an object's properties</title>
 700 *   <programlisting>
 701 *   Error *err = NULL;
 702 *   Object *obj = ...get / create object...;
 703 *
 704 *   obj = object_set_props(obj,
 705 *                          &err,
 706 *                          "share", "yes",
 707 *                          "mem-path", "/dev/shm/somefile",
 708 *                          "prealloc", "yes",
 709 *                          "size", "1048576",
 710 *                          NULL);
 711 *
 712 *   if (!obj) {
 713 *     g_printerr("Cannot set properties: %s\n",
 714 *                error_get_pretty(err));
 715 *   }
 716 *   </programlisting>
 717 * </example>
 718 *
 719 * The returned object will have one stable reference maintained
 720 * for as long as it is present in the object hierarchy.
 721 *
 722 * Returns: -1 on error, 0 on success
 723 */
 724int object_set_props(Object *obj,
 725                     Error **errp,
 726                     ...) QEMU_SENTINEL;
 727
 728/**
 729 * object_set_propv:
 730 * @obj: the object instance to set properties on
 731 * @errp: pointer to error object
 732 * @vargs: list of property names and values
 733 *
 734 * See object_set_props() for documentation.
 735 *
 736 * Returns: -1 on error, 0 on success
 737 */
 738int object_set_propv(Object *obj,
 739                     Error **errp,
 740                     va_list vargs);
 741
 742/**
 743 * object_initialize:
 744 * @obj: A pointer to the memory to be used for the object.
 745 * @size: The maximum size available at @obj for the object.
 746 * @typename: The name of the type of the object to instantiate.
 747 *
 748 * This function will initialize an object.  The memory for the object should
 749 * have already been allocated.  The returned object has a reference count of 1,
 750 * and will be finalized when the last reference is dropped.
 751 */
 752void object_initialize(void *obj, size_t size, const char *typename);
 753
 754/**
 755 * object_initialize_child:
 756 * @parentobj: The parent object to add a property to
 757 * @propname: The name of the property
 758 * @childobj: A pointer to the memory to be used for the object.
 759 * @size: The maximum size available at @childobj for the object.
 760 * @type: The name of the type of the object to instantiate.
 761 * @errp: If an error occurs, a pointer to an area to store the error
 762 * @...: list of property names and values
 763 *
 764 * This function will initialize an object. The memory for the object should
 765 * have already been allocated. The object will then be added as child property
 766 * to a parent with object_property_add_child() function. The returned object
 767 * has a reference count of 1 (for the "child<...>" property from the parent),
 768 * so the object will be finalized automatically when the parent gets removed.
 769 *
 770 * The variadic parameters are a list of pairs of (propname, propvalue)
 771 * strings. The propname of %NULL indicates the end of the property list.
 772 * If the object implements the user creatable interface, the object will
 773 * be marked complete once all the properties have been processed.
 774 */
 775void object_initialize_child(Object *parentobj, const char *propname,
 776                             void *childobj, size_t size, const char *type,
 777                             Error **errp, ...) QEMU_SENTINEL;
 778
 779/**
 780 * object_initialize_childv:
 781 * @parentobj: The parent object to add a property to
 782 * @propname: The name of the property
 783 * @childobj: A pointer to the memory to be used for the object.
 784 * @size: The maximum size available at @childobj for the object.
 785 * @type: The name of the type of the object to instantiate.
 786 * @errp: If an error occurs, a pointer to an area to store the error
 787 * @vargs: list of property names and values
 788 *
 789 * See object_initialize_child() for documentation.
 790 */
 791void object_initialize_childv(Object *parentobj, const char *propname,
 792                              void *childobj, size_t size, const char *type,
 793                              Error **errp, va_list vargs);
 794
 795/**
 796 * object_dynamic_cast:
 797 * @obj: The object to cast.
 798 * @typename: The @typename to cast to.
 799 *
 800 * This function will determine if @obj is-a @typename.  @obj can refer to an
 801 * object or an interface associated with an object.
 802 *
 803 * Returns: This function returns @obj on success or #NULL on failure.
 804 */
 805Object *object_dynamic_cast(Object *obj, const char *typename);
 806
 807/**
 808 * object_dynamic_cast_assert:
 809 *
 810 * See object_dynamic_cast() for a description of the parameters of this
 811 * function.  The only difference in behavior is that this function asserts
 812 * instead of returning #NULL on failure if QOM cast debugging is enabled.
 813 * This function is not meant to be called directly, but only through
 814 * the wrapper macro OBJECT_CHECK.
 815 */
 816Object *object_dynamic_cast_assert(Object *obj, const char *typename,
 817                                   const char *file, int line, const char *func);
 818
 819/**
 820 * object_get_class:
 821 * @obj: A derivative of #Object
 822 *
 823 * Returns: The #ObjectClass of the type associated with @obj.
 824 */
 825ObjectClass *object_get_class(Object *obj);
 826
 827/**
 828 * object_get_typename:
 829 * @obj: A derivative of #Object.
 830 *
 831 * Returns: The QOM typename of @obj.
 832 */
 833const char *object_get_typename(const Object *obj);
 834
 835/**
 836 * type_register_static:
 837 * @info: The #TypeInfo of the new type.
 838 *
 839 * @info and all of the strings it points to should exist for the life time
 840 * that the type is registered.
 841 *
 842 * Returns: the new #Type.
 843 */
 844Type type_register_static(const TypeInfo *info);
 845
 846/**
 847 * type_register:
 848 * @info: The #TypeInfo of the new type
 849 *
 850 * Unlike type_register_static(), this call does not require @info or its
 851 * string members to continue to exist after the call returns.
 852 *
 853 * Returns: the new #Type.
 854 */
 855Type type_register(const TypeInfo *info);
 856
 857/**
 858 * type_register_static_array:
 859 * @infos: The array of the new type #TypeInfo structures.
 860 * @nr_infos: number of entries in @infos
 861 *
 862 * @infos and all of the strings it points to should exist for the life time
 863 * that the type is registered.
 864 */
 865void type_register_static_array(const TypeInfo *infos, int nr_infos);
 866
 867/**
 868 * DEFINE_TYPES:
 869 * @type_array: The array containing #TypeInfo structures to register
 870 *
 871 * @type_array should be static constant that exists for the life time
 872 * that the type is registered.
 873 */
 874#define DEFINE_TYPES(type_array)                                            \
 875static void do_qemu_init_ ## type_array(void)                               \
 876{                                                                           \
 877    type_register_static_array(type_array, ARRAY_SIZE(type_array));         \
 878}                                                                           \
 879type_init(do_qemu_init_ ## type_array)
 880
 881/**
 882 * object_class_dynamic_cast_assert:
 883 * @klass: The #ObjectClass to attempt to cast.
 884 * @typename: The QOM typename of the class to cast to.
 885 *
 886 * See object_class_dynamic_cast() for a description of the parameters
 887 * of this function.  The only difference in behavior is that this function
 888 * asserts instead of returning #NULL on failure if QOM cast debugging is
 889 * enabled.  This function is not meant to be called directly, but only through
 890 * the wrapper macros OBJECT_CLASS_CHECK and INTERFACE_CHECK.
 891 */
 892ObjectClass *object_class_dynamic_cast_assert(ObjectClass *klass,
 893                                              const char *typename,
 894                                              const char *file, int line,
 895                                              const char *func);
 896
 897/**
 898 * object_class_dynamic_cast:
 899 * @klass: The #ObjectClass to attempt to cast.
 900 * @typename: The QOM typename of the class to cast to.
 901 *
 902 * Returns: If @typename is a class, this function returns @klass if
 903 * @typename is a subtype of @klass, else returns #NULL.
 904 *
 905 * If @typename is an interface, this function returns the interface
 906 * definition for @klass if @klass implements it unambiguously; #NULL
 907 * is returned if @klass does not implement the interface or if multiple
 908 * classes or interfaces on the hierarchy leading to @klass implement
 909 * it.  (FIXME: perhaps this can be detected at type definition time?)
 910 */
 911ObjectClass *object_class_dynamic_cast(ObjectClass *klass,
 912                                       const char *typename);
 913
 914/**
 915 * object_class_get_parent:
 916 * @klass: The class to obtain the parent for.
 917 *
 918 * Returns: The parent for @klass or %NULL if none.
 919 */
 920ObjectClass *object_class_get_parent(ObjectClass *klass);
 921
 922/**
 923 * object_class_get_name:
 924 * @klass: The class to obtain the QOM typename for.
 925 *
 926 * Returns: The QOM typename for @klass.
 927 */
 928const char *object_class_get_name(ObjectClass *klass);
 929
 930/**
 931 * object_class_is_abstract:
 932 * @klass: The class to obtain the abstractness for.
 933 *
 934 * Returns: %true if @klass is abstract, %false otherwise.
 935 */
 936bool object_class_is_abstract(ObjectClass *klass);
 937
 938/**
 939 * object_class_by_name:
 940 * @typename: The QOM typename to obtain the class for.
 941 *
 942 * Returns: The class for @typename or %NULL if not found.
 943 */
 944ObjectClass *object_class_by_name(const char *typename);
 945
 946void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
 947                          const char *implements_type, bool include_abstract,
 948                          void *opaque);
 949
 950/**
 951 * object_class_get_list:
 952 * @implements_type: The type to filter for, including its derivatives.
 953 * @include_abstract: Whether to include abstract classes.
 954 *
 955 * Returns: A singly-linked list of the classes in reverse hashtable order.
 956 */
 957GSList *object_class_get_list(const char *implements_type,
 958                              bool include_abstract);
 959
 960/**
 961 * object_class_get_list_sorted:
 962 * @implements_type: The type to filter for, including its derivatives.
 963 * @include_abstract: Whether to include abstract classes.
 964 *
 965 * Returns: A singly-linked list of the classes in alphabetical
 966 * case-insensitive order.
 967 */
 968GSList *object_class_get_list_sorted(const char *implements_type,
 969                              bool include_abstract);
 970
 971/**
 972 * object_ref:
 973 * @obj: the object
 974 *
 975 * Increase the reference count of a object.  A object cannot be freed as long
 976 * as its reference count is greater than zero.
 977 */
 978void object_ref(Object *obj);
 979
 980/**
 981 * object_unref:
 982 * @obj: the object
 983 *
 984 * Decrease the reference count of a object.  A object cannot be freed as long
 985 * as its reference count is greater than zero.
 986 */
 987void object_unref(Object *obj);
 988
 989/**
 990 * object_property_add:
 991 * @obj: the object to add a property to
 992 * @name: the name of the property.  This can contain any character except for
 993 *  a forward slash.  In general, you should use hyphens '-' instead of
 994 *  underscores '_' when naming properties.
 995 * @type: the type name of the property.  This namespace is pretty loosely
 996 *   defined.  Sub namespaces are constructed by using a prefix and then
 997 *   to angle brackets.  For instance, the type 'virtio-net-pci' in the
 998 *   'link' namespace would be 'link<virtio-net-pci>'.
 999 * @get: The getter to be called to read a property.  If this is NULL, then
1000 *   the property cannot be read.
1001 * @set: the setter to be called to write a property.  If this is NULL,
1002 *   then the property cannot be written.
1003 * @release: called when the property is removed from the object.  This is
1004 *   meant to allow a property to free its opaque upon object
1005 *   destruction.  This may be NULL.
1006 * @opaque: an opaque pointer to pass to the callbacks for the property
1007 * @errp: returns an error if this function fails
1008 *
1009 * Returns: The #ObjectProperty; this can be used to set the @resolve
1010 * callback for child and link properties.
1011 */
1012ObjectProperty *object_property_add(Object *obj, const char *name,
1013                                    const char *type,
1014                                    ObjectPropertyAccessor *get,
1015                                    ObjectPropertyAccessor *set,
1016                                    ObjectPropertyRelease *release,
1017                                    void *opaque, Error **errp);
1018
1019void object_property_del(Object *obj, const char *name, Error **errp);
1020
1021ObjectProperty *object_class_property_add(ObjectClass *klass, const char *name,
1022                                          const char *type,
1023                                          ObjectPropertyAccessor *get,
1024                                          ObjectPropertyAccessor *set,
1025                                          ObjectPropertyRelease *release,
1026                                          void *opaque, Error **errp);
1027
1028/**
1029 * object_property_find:
1030 * @obj: the object
1031 * @name: the name of the property
1032 * @errp: returns an error if this function fails
1033 *
1034 * Look up a property for an object and return its #ObjectProperty if found.
1035 */
1036ObjectProperty *object_property_find(Object *obj, const char *name,
1037                                     Error **errp);
1038ObjectProperty *object_class_property_find(ObjectClass *klass, const char *name,
1039                                           Error **errp);
1040
1041typedef struct ObjectPropertyIterator {
1042    ObjectClass *nextclass;
1043    GHashTableIter iter;
1044} ObjectPropertyIterator;
1045
1046/**
1047 * object_property_iter_init:
1048 * @obj: the object
1049 *
1050 * Initializes an iterator for traversing all properties
1051 * registered against an object instance, its class and all parent classes.
1052 *
1053 * It is forbidden to modify the property list while iterating,
1054 * whether removing or adding properties.
1055 *
1056 * Typical usage pattern would be
1057 *
1058 * <example>
1059 *   <title>Using object property iterators</title>
1060 *   <programlisting>
1061 *   ObjectProperty *prop;
1062 *   ObjectPropertyIterator iter;
1063 *
1064 *   object_property_iter_init(&iter, obj);
1065 *   while ((prop = object_property_iter_next(&iter))) {
1066 *     ... do something with prop ...
1067 *   }
1068 *   </programlisting>
1069 * </example>
1070 */
1071void object_property_iter_init(ObjectPropertyIterator *iter,
1072                               Object *obj);
1073
1074/**
1075 * object_class_property_iter_init:
1076 * @klass: the class
1077 *
1078 * Initializes an iterator for traversing all properties
1079 * registered against an object class and all parent classes.
1080 *
1081 * It is forbidden to modify the property list while iterating,
1082 * whether removing or adding properties.
1083 *
1084 * This can be used on abstract classes as it does not create a temporary
1085 * instance.
1086 */
1087void object_class_property_iter_init(ObjectPropertyIterator *iter,
1088                                     ObjectClass *klass);
1089
1090/**
1091 * object_property_iter_next:
1092 * @iter: the iterator instance
1093 *
1094 * Return the next available property. If no further properties
1095 * are available, a %NULL value will be returned and the @iter
1096 * pointer should not be used again after this point without
1097 * re-initializing it.
1098 *
1099 * Returns: the next property, or %NULL when all properties
1100 * have been traversed.
1101 */
1102ObjectProperty *object_property_iter_next(ObjectPropertyIterator *iter);
1103
1104void object_unparent(Object *obj);
1105
1106/**
1107 * object_property_get:
1108 * @obj: the object
1109 * @v: the visitor that will receive the property value.  This should be an
1110 *   Output visitor and the data will be written with @name as the name.
1111 * @name: the name of the property
1112 * @errp: returns an error if this function fails
1113 *
1114 * Reads a property from a object.
1115 */
1116void object_property_get(Object *obj, Visitor *v, const char *name,
1117                         Error **errp);
1118
1119/**
1120 * object_property_set_str:
1121 * @value: the value to be written to the property
1122 * @name: the name of the property
1123 * @errp: returns an error if this function fails
1124 *
1125 * Writes a string value to a property.
1126 */
1127void object_property_set_str(Object *obj, const char *value,
1128                             const char *name, Error **errp);
1129
1130/**
1131 * object_property_get_str:
1132 * @obj: the object
1133 * @name: the name of the property
1134 * @errp: returns an error if this function fails
1135 *
1136 * Returns: the value of the property, converted to a C string, or NULL if
1137 * an error occurs (including when the property value is not a string).
1138 * The caller should free the string.
1139 */
1140char *object_property_get_str(Object *obj, const char *name,
1141                              Error **errp);
1142
1143/**
1144 * object_property_set_link:
1145 * @value: the value to be written to the property
1146 * @name: the name of the property
1147 * @errp: returns an error if this function fails
1148 *
1149 * Writes an object's canonical path to a property.
1150 *
1151 * If the link property was created with
1152 * <code>OBJ_PROP_LINK_STRONG</code> bit, the old target object is
1153 * unreferenced, and a reference is added to the new target object.
1154 *
1155 */
1156void object_property_set_link(Object *obj, Object *value,
1157                              const char *name, Error **errp);
1158
1159/**
1160 * object_property_get_link:
1161 * @obj: the object
1162 * @name: the name of the property
1163 * @errp: returns an error if this function fails
1164 *
1165 * Returns: the value of the property, resolved from a path to an Object,
1166 * or NULL if an error occurs (including when the property value is not a
1167 * string or not a valid object path).
1168 */
1169Object *object_property_get_link(Object *obj, const char *name,
1170                                 Error **errp);
1171
1172/**
1173 * object_property_set_bool:
1174 * @value: the value to be written to the property
1175 * @name: the name of the property
1176 * @errp: returns an error if this function fails
1177 *
1178 * Writes a bool value to a property.
1179 */
1180void object_property_set_bool(Object *obj, bool value,
1181                              const char *name, Error **errp);
1182
1183/**
1184 * object_property_get_bool:
1185 * @obj: the object
1186 * @name: the name of the property
1187 * @errp: returns an error if this function fails
1188 *
1189 * Returns: the value of the property, converted to a boolean, or NULL if
1190 * an error occurs (including when the property value is not a bool).
1191 */
1192bool object_property_get_bool(Object *obj, const char *name,
1193                              Error **errp);
1194
1195/**
1196 * object_property_set_int:
1197 * @value: the value to be written to the property
1198 * @name: the name of the property
1199 * @errp: returns an error if this function fails
1200 *
1201 * Writes an integer value to a property.
1202 */
1203void object_property_set_int(Object *obj, int64_t value,
1204                             const char *name, Error **errp);
1205
1206/**
1207 * object_property_get_int:
1208 * @obj: the object
1209 * @name: the name of the property
1210 * @errp: returns an error if this function fails
1211 *
1212 * Returns: the value of the property, converted to an integer, or negative if
1213 * an error occurs (including when the property value is not an integer).
1214 */
1215int64_t object_property_get_int(Object *obj, const char *name,
1216                                Error **errp);
1217
1218/**
1219 * object_property_set_uint:
1220 * @value: the value to be written to the property
1221 * @name: the name of the property
1222 * @errp: returns an error if this function fails
1223 *
1224 * Writes an unsigned integer value to a property.
1225 */
1226void object_property_set_uint(Object *obj, uint64_t value,
1227                              const char *name, Error **errp);
1228
1229/**
1230 * object_property_get_uint:
1231 * @obj: the object
1232 * @name: the name of the property
1233 * @errp: returns an error if this function fails
1234 *
1235 * Returns: the value of the property, converted to an unsigned integer, or 0
1236 * an error occurs (including when the property value is not an integer).
1237 */
1238uint64_t object_property_get_uint(Object *obj, const char *name,
1239                                  Error **errp);
1240
1241/**
1242 * object_property_get_enum:
1243 * @obj: the object
1244 * @name: the name of the property
1245 * @typename: the name of the enum data type
1246 * @errp: returns an error if this function fails
1247 *
1248 * Returns: the value of the property, converted to an integer, or
1249 * undefined if an error occurs (including when the property value is not
1250 * an enum).
1251 */
1252int object_property_get_enum(Object *obj, const char *name,
1253                             const char *typename, Error **errp);
1254
1255/**
1256 * object_property_get_uint16List:
1257 * @obj: the object
1258 * @name: the name of the property
1259 * @list: the returned int list
1260 * @errp: returns an error if this function fails
1261 *
1262 * Returns: the value of the property, converted to integers, or
1263 * undefined if an error occurs (including when the property value is not
1264 * an list of integers).
1265 */
1266void object_property_get_uint16List(Object *obj, const char *name,
1267                                    uint16List **list, Error **errp);
1268
1269/**
1270 * object_property_set:
1271 * @obj: the object
1272 * @v: the visitor that will be used to write the property value.  This should
1273 *   be an Input visitor and the data will be first read with @name as the
1274 *   name and then written as the property value.
1275 * @name: the name of the property
1276 * @errp: returns an error if this function fails
1277 *
1278 * Writes a property to a object.
1279 */
1280void object_property_set(Object *obj, Visitor *v, const char *name,
1281                         Error **errp);
1282
1283/**
1284 * object_property_parse:
1285 * @obj: the object
1286 * @string: the string that will be used to parse the property value.
1287 * @name: the name of the property
1288 * @errp: returns an error if this function fails
1289 *
1290 * Parses a string and writes the result into a property of an object.
1291 */
1292void object_property_parse(Object *obj, const char *string,
1293                           const char *name, Error **errp);
1294
1295/**
1296 * object_property_print:
1297 * @obj: the object
1298 * @name: the name of the property
1299 * @human: if true, print for human consumption
1300 * @errp: returns an error if this function fails
1301 *
1302 * Returns a string representation of the value of the property.  The
1303 * caller shall free the string.
1304 */
1305char *object_property_print(Object *obj, const char *name, bool human,
1306                            Error **errp);
1307
1308/**
1309 * object_property_get_type:
1310 * @obj: the object
1311 * @name: the name of the property
1312 * @errp: returns an error if this function fails
1313 *
1314 * Returns:  The type name of the property.
1315 */
1316const char *object_property_get_type(Object *obj, const char *name,
1317                                     Error **errp);
1318
1319/**
1320 * object_get_root:
1321 *
1322 * Returns: the root object of the composition tree
1323 */
1324Object *object_get_root(void);
1325
1326
1327/**
1328 * object_get_objects_root:
1329 *
1330 * Get the container object that holds user created
1331 * object instances. This is the object at path
1332 * "/objects"
1333 *
1334 * Returns: the user object container
1335 */
1336Object *object_get_objects_root(void);
1337
1338/**
1339 * object_get_internal_root:
1340 *
1341 * Get the container object that holds internally used object
1342 * instances.  Any object which is put into this container must not be
1343 * user visible, and it will not be exposed in the QOM tree.
1344 *
1345 * Returns: the internal object container
1346 */
1347Object *object_get_internal_root(void);
1348
1349/**
1350 * object_get_canonical_path_component:
1351 *
1352 * Returns: The final component in the object's canonical path.  The canonical
1353 * path is the path within the composition tree starting from the root.
1354 * %NULL if the object doesn't have a parent (and thus a canonical path).
1355 */
1356gchar *object_get_canonical_path_component(Object *obj);
1357
1358/**
1359 * object_get_canonical_path:
1360 *
1361 * Returns: The canonical path for a object.  This is the path within the
1362 * composition tree starting from the root.
1363 */
1364gchar *object_get_canonical_path(Object *obj);
1365
1366/**
1367 * object_resolve_path:
1368 * @path: the path to resolve
1369 * @ambiguous: returns true if the path resolution failed because of an
1370 *   ambiguous match
1371 *
1372 * There are two types of supported paths--absolute paths and partial paths.
1373 * 
1374 * Absolute paths are derived from the root object and can follow child<> or
1375 * link<> properties.  Since they can follow link<> properties, they can be
1376 * arbitrarily long.  Absolute paths look like absolute filenames and are
1377 * prefixed with a leading slash.
1378 * 
1379 * Partial paths look like relative filenames.  They do not begin with a
1380 * prefix.  The matching rules for partial paths are subtle but designed to make
1381 * specifying objects easy.  At each level of the composition tree, the partial
1382 * path is matched as an absolute path.  The first match is not returned.  At
1383 * least two matches are searched for.  A successful result is only returned if
1384 * only one match is found.  If more than one match is found, a flag is
1385 * returned to indicate that the match was ambiguous.
1386 *
1387 * Returns: The matched object or NULL on path lookup failure.
1388 */
1389Object *object_resolve_path(const char *path, bool *ambiguous);
1390
1391/**
1392 * object_resolve_path_type:
1393 * @path: the path to resolve
1394 * @typename: the type to look for.
1395 * @ambiguous: returns true if the path resolution failed because of an
1396 *   ambiguous match
1397 *
1398 * This is similar to object_resolve_path.  However, when looking for a
1399 * partial path only matches that implement the given type are considered.
1400 * This restricts the search and avoids spuriously flagging matches as
1401 * ambiguous.
1402 *
1403 * For both partial and absolute paths, the return value goes through
1404 * a dynamic cast to @typename.  This is important if either the link,
1405 * or the typename itself are of interface types.
1406 *
1407 * Returns: The matched object or NULL on path lookup failure.
1408 */
1409Object *object_resolve_path_type(const char *path, const char *typename,
1410                                 bool *ambiguous);
1411
1412/**
1413 * object_resolve_path_component:
1414 * @parent: the object in which to resolve the path
1415 * @part: the component to resolve.
1416 *
1417 * This is similar to object_resolve_path with an absolute path, but it
1418 * only resolves one element (@part) and takes the others from @parent.
1419 *
1420 * Returns: The resolved object or NULL on path lookup failure.
1421 */
1422Object *object_resolve_path_component(Object *parent, const gchar *part);
1423
1424/**
1425 * object_property_add_child:
1426 * @obj: the object to add a property to
1427 * @name: the name of the property
1428 * @child: the child object
1429 * @errp: if an error occurs, a pointer to an area to store the error
1430 *
1431 * Child properties form the composition tree.  All objects need to be a child
1432 * of another object.  Objects can only be a child of one object.
1433 *
1434 * There is no way for a child to determine what its parent is.  It is not
1435 * a bidirectional relationship.  This is by design.
1436 *
1437 * The value of a child property as a C string will be the child object's
1438 * canonical path. It can be retrieved using object_property_get_str().
1439 * The child object itself can be retrieved using object_property_get_link().
1440 */
1441void object_property_add_child(Object *obj, const char *name,
1442                               Object *child, Error **errp);
1443
1444typedef enum {
1445    /* Unref the link pointer when the property is deleted */
1446    OBJ_PROP_LINK_STRONG = 0x1,
1447} ObjectPropertyLinkFlags;
1448
1449/**
1450 * object_property_allow_set_link:
1451 *
1452 * The default implementation of the object_property_add_link() check()
1453 * callback function.  It allows the link property to be set and never returns
1454 * an error.
1455 */
1456void object_property_allow_set_link(const Object *, const char *,
1457                                    Object *, Error **);
1458
1459/**
1460 * object_property_add_link:
1461 * @obj: the object to add a property to
1462 * @name: the name of the property
1463 * @type: the qobj type of the link
1464 * @child: a pointer to where the link object reference is stored
1465 * @check: callback to veto setting or NULL if the property is read-only
1466 * @flags: additional options for the link
1467 * @errp: if an error occurs, a pointer to an area to store the error
1468 *
1469 * Links establish relationships between objects.  Links are unidirectional
1470 * although two links can be combined to form a bidirectional relationship
1471 * between objects.
1472 *
1473 * Links form the graph in the object model.
1474 *
1475 * The <code>@check()</code> callback is invoked when
1476 * object_property_set_link() is called and can raise an error to prevent the
1477 * link being set.  If <code>@check</code> is NULL, the property is read-only
1478 * and cannot be set.
1479 *
1480 * Ownership of the pointer that @child points to is transferred to the
1481 * link property.  The reference count for <code>*@child</code> is
1482 * managed by the property from after the function returns till the
1483 * property is deleted with object_property_del().  If the
1484 * <code>@flags</code> <code>OBJ_PROP_LINK_STRONG</code> bit is set,
1485 * the reference count is decremented when the property is deleted or
1486 * modified.
1487 */
1488void object_property_add_link(Object *obj, const char *name,
1489                              const char *type, Object **child,
1490                              void (*check)(const Object *obj, const char *name,
1491                                            Object *val, Error **errp),
1492                              ObjectPropertyLinkFlags flags,
1493                              Error **errp);
1494
1495/**
1496 * object_property_add_str:
1497 * @obj: the object to add a property to
1498 * @name: the name of the property
1499 * @get: the getter or NULL if the property is write-only.  This function must
1500 *   return a string to be freed by g_free().
1501 * @set: the setter or NULL if the property is read-only
1502 * @errp: if an error occurs, a pointer to an area to store the error
1503 *
1504 * Add a string property using getters/setters.  This function will add a
1505 * property of type 'string'.
1506 */
1507void object_property_add_str(Object *obj, const char *name,
1508                             char *(*get)(Object *, Error **),
1509                             void (*set)(Object *, const char *, Error **),
1510                             Error **errp);
1511
1512void object_class_property_add_str(ObjectClass *klass, const char *name,
1513                                   char *(*get)(Object *, Error **),
1514                                   void (*set)(Object *, const char *,
1515                                               Error **),
1516                                   Error **errp);
1517
1518/**
1519 * object_property_add_bool:
1520 * @obj: the object to add a property to
1521 * @name: the name of the property
1522 * @get: the getter or NULL if the property is write-only.
1523 * @set: the setter or NULL if the property is read-only
1524 * @errp: if an error occurs, a pointer to an area to store the error
1525 *
1526 * Add a bool property using getters/setters.  This function will add a
1527 * property of type 'bool'.
1528 */
1529void object_property_add_bool(Object *obj, const char *name,
1530                              bool (*get)(Object *, Error **),
1531                              void (*set)(Object *, bool, Error **),
1532                              Error **errp);
1533
1534void object_class_property_add_bool(ObjectClass *klass, const char *name,
1535                                    bool (*get)(Object *, Error **),
1536                                    void (*set)(Object *, bool, Error **),
1537                                    Error **errp);
1538
1539/**
1540 * object_property_add_enum:
1541 * @obj: the object to add a property to
1542 * @name: the name of the property
1543 * @typename: the name of the enum data type
1544 * @get: the getter or %NULL if the property is write-only.
1545 * @set: the setter or %NULL if the property is read-only
1546 * @errp: if an error occurs, a pointer to an area to store the error
1547 *
1548 * Add an enum property using getters/setters.  This function will add a
1549 * property of type '@typename'.
1550 */
1551void object_property_add_enum(Object *obj, const char *name,
1552                              const char *typename,
1553                              const QEnumLookup *lookup,
1554                              int (*get)(Object *, Error **),
1555                              void (*set)(Object *, int, Error **),
1556                              Error **errp);
1557
1558void object_class_property_add_enum(ObjectClass *klass, const char *name,
1559                                    const char *typename,
1560                                    const QEnumLookup *lookup,
1561                                    int (*get)(Object *, Error **),
1562                                    void (*set)(Object *, int, Error **),
1563                                    Error **errp);
1564
1565/**
1566 * object_property_add_tm:
1567 * @obj: the object to add a property to
1568 * @name: the name of the property
1569 * @get: the getter or NULL if the property is write-only.
1570 * @errp: if an error occurs, a pointer to an area to store the error
1571 *
1572 * Add a read-only struct tm valued property using a getter function.
1573 * This function will add a property of type 'struct tm'.
1574 */
1575void object_property_add_tm(Object *obj, const char *name,
1576                            void (*get)(Object *, struct tm *, Error **),
1577                            Error **errp);
1578
1579void object_class_property_add_tm(ObjectClass *klass, const char *name,
1580                                  void (*get)(Object *, struct tm *, Error **),
1581                                  Error **errp);
1582
1583/**
1584 * object_property_add_uint8_ptr:
1585 * @obj: the object to add a property to
1586 * @name: the name of the property
1587 * @v: pointer to value
1588 * @errp: if an error occurs, a pointer to an area to store the error
1589 *
1590 * Add an integer property in memory.  This function will add a
1591 * property of type 'uint8'.
1592 */
1593void object_property_add_uint8_ptr(Object *obj, const char *name,
1594                                   const uint8_t *v, Error **errp);
1595void object_class_property_add_uint8_ptr(ObjectClass *klass, const char *name,
1596                                         const uint8_t *v, Error **errp);
1597
1598/**
1599 * object_property_add_uint16_ptr:
1600 * @obj: the object to add a property to
1601 * @name: the name of the property
1602 * @v: pointer to value
1603 * @errp: if an error occurs, a pointer to an area to store the error
1604 *
1605 * Add an integer property in memory.  This function will add a
1606 * property of type 'uint16'.
1607 */
1608void object_property_add_uint16_ptr(Object *obj, const char *name,
1609                                    const uint16_t *v, Error **errp);
1610void object_class_property_add_uint16_ptr(ObjectClass *klass, const char *name,
1611                                          const uint16_t *v, Error **errp);
1612
1613/**
1614 * object_property_add_uint32_ptr:
1615 * @obj: the object to add a property to
1616 * @name: the name of the property
1617 * @v: pointer to value
1618 * @errp: if an error occurs, a pointer to an area to store the error
1619 *
1620 * Add an integer property in memory.  This function will add a
1621 * property of type 'uint32'.
1622 */
1623void object_property_add_uint32_ptr(Object *obj, const char *name,
1624                                    const uint32_t *v, Error **errp);
1625void object_class_property_add_uint32_ptr(ObjectClass *klass, const char *name,
1626                                          const uint32_t *v, Error **errp);
1627
1628/**
1629 * object_property_add_uint64_ptr:
1630 * @obj: the object to add a property to
1631 * @name: the name of the property
1632 * @v: pointer to value
1633 * @errp: if an error occurs, a pointer to an area to store the error
1634 *
1635 * Add an integer property in memory.  This function will add a
1636 * property of type 'uint64'.
1637 */
1638void object_property_add_uint64_ptr(Object *obj, const char *name,
1639                                    const uint64_t *v, Error **Errp);
1640void object_class_property_add_uint64_ptr(ObjectClass *klass, const char *name,
1641                                          const uint64_t *v, Error **Errp);
1642
1643/**
1644 * object_property_add_alias:
1645 * @obj: the object to add a property to
1646 * @name: the name of the property
1647 * @target_obj: the object to forward property access to
1648 * @target_name: the name of the property on the forwarded object
1649 * @errp: if an error occurs, a pointer to an area to store the error
1650 *
1651 * Add an alias for a property on an object.  This function will add a property
1652 * of the same type as the forwarded property.
1653 *
1654 * The caller must ensure that <code>@target_obj</code> stays alive as long as
1655 * this property exists.  In the case of a child object or an alias on the same
1656 * object this will be the case.  For aliases to other objects the caller is
1657 * responsible for taking a reference.
1658 */
1659void object_property_add_alias(Object *obj, const char *name,
1660                               Object *target_obj, const char *target_name,
1661                               Error **errp);
1662
1663/**
1664 * object_property_add_const_link:
1665 * @obj: the object to add a property to
1666 * @name: the name of the property
1667 * @target: the object to be referred by the link
1668 * @errp: if an error occurs, a pointer to an area to store the error
1669 *
1670 * Add an unmodifiable link for a property on an object.  This function will
1671 * add a property of type link<TYPE> where TYPE is the type of @target.
1672 *
1673 * The caller must ensure that @target stays alive as long as
1674 * this property exists.  In the case @target is a child of @obj,
1675 * this will be the case.  Otherwise, the caller is responsible for
1676 * taking a reference.
1677 */
1678void object_property_add_const_link(Object *obj, const char *name,
1679                                    Object *target, Error **errp);
1680
1681/**
1682 * object_property_set_description:
1683 * @obj: the object owning the property
1684 * @name: the name of the property
1685 * @description: the description of the property on the object
1686 * @errp: if an error occurs, a pointer to an area to store the error
1687 *
1688 * Set an object property's description.
1689 *
1690 */
1691void object_property_set_description(Object *obj, const char *name,
1692                                     const char *description, Error **errp);
1693void object_class_property_set_description(ObjectClass *klass, const char *name,
1694                                           const char *description,
1695                                           Error **errp);
1696
1697/**
1698 * object_child_foreach:
1699 * @obj: the object whose children will be navigated
1700 * @fn: the iterator function to be called
1701 * @opaque: an opaque value that will be passed to the iterator
1702 *
1703 * Call @fn passing each child of @obj and @opaque to it, until @fn returns
1704 * non-zero.
1705 *
1706 * It is forbidden to add or remove children from @obj from the @fn
1707 * callback.
1708 *
1709 * Returns: The last value returned by @fn, or 0 if there is no child.
1710 */
1711int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
1712                         void *opaque);
1713
1714/**
1715 * object_child_foreach_recursive:
1716 * @obj: the object whose children will be navigated
1717 * @fn: the iterator function to be called
1718 * @opaque: an opaque value that will be passed to the iterator
1719 *
1720 * Call @fn passing each child of @obj and @opaque to it, until @fn returns
1721 * non-zero. Calls recursively, all child nodes of @obj will also be passed
1722 * all the way down to the leaf nodes of the tree. Depth first ordering.
1723 *
1724 * It is forbidden to add or remove children from @obj (or its
1725 * child nodes) from the @fn callback.
1726 *
1727 * Returns: The last value returned by @fn, or 0 if there is no child.
1728 */
1729int object_child_foreach_recursive(Object *obj,
1730                                   int (*fn)(Object *child, void *opaque),
1731                                   void *opaque);
1732/**
1733 * container_get:
1734 * @root: root of the #path, e.g., object_get_root()
1735 * @path: path to the container
1736 *
1737 * Return a container object whose path is @path.  Create more containers
1738 * along the path if necessary.
1739 *
1740 * Returns: the container object.
1741 */
1742Object *container_get(Object *root, const char *path);
1743
1744/**
1745 * object_type_get_instance_size:
1746 * @typename: Name of the Type whose instance_size is required
1747 *
1748 * Returns the instance_size of the given @typename.
1749 */
1750size_t object_type_get_instance_size(const char *typename);
1751#endif
1752