#define TYPE_OBJECT "object"
-/**
- * DOC:
- *
- * .. highlight:: c
- *
- * The QEMU Object Model provides a framework for registering user creatable
- * types and instantiating objects from those types. QOM provides the following
- * features:
- *
- * - System for dynamically registering types
- * - Support for single-inheritance of types
- * - Multiple inheritance of stateless interfaces
- *
- * .. code-block:: c
- * :caption: Creating a minimal type
- *
- * #include "qdev.h"
- *
- * #define TYPE_MY_DEVICE "my-device"
- *
- * // No new virtual functions: we can reuse the typedef for the
- * // superclass.
- * typedef DeviceClass MyDeviceClass;
- * typedef struct MyDevice
- * {
- * DeviceState parent;
- *
- * int reg0, reg1, reg2;
- * } MyDevice;
- *
- * static const TypeInfo my_device_info = {
- * .name = TYPE_MY_DEVICE,
- * .parent = TYPE_DEVICE,
- * .instance_size = sizeof(MyDevice),
- * };
- *
- * static void my_device_register_types(void)
- * {
- * type_register_static(&my_device_info);
- * }
- *
- * type_init(my_device_register_types)
- *
- * In the above example, we create a simple type that is described by #TypeInfo.
- * #TypeInfo describes information about the type including what it inherits
- * from, the instance and class size, and constructor/destructor hooks.
- *
- * Alternatively several static types could be registered using helper macro
- * DEFINE_TYPES()
- *
- * .. code-block:: c
- *
- * static const TypeInfo device_types_info[] = {
- * {
- * .name = TYPE_MY_DEVICE_A,
- * .parent = TYPE_DEVICE,
- * .instance_size = sizeof(MyDeviceA),
- * },
- * {
- * .name = TYPE_MY_DEVICE_B,
- * .parent = TYPE_DEVICE,
- * .instance_size = sizeof(MyDeviceB),
- * },
- * };
- *
- * DEFINE_TYPES(device_types_info)
- *
- * Every type has an #ObjectClass associated with it. #ObjectClass derivatives
- * are instantiated dynamically but there is only ever one instance for any
- * given type. The #ObjectClass typically holds a table of function pointers
- * for the virtual methods implemented by this type.
- *
- * Using object_new(), a new #Object derivative will be instantiated. You can
- * cast an #Object to a subclass (or base-class) type using
- * object_dynamic_cast(). You typically want to define macro wrappers around
- * OBJECT_CHECK() and OBJECT_CLASS_CHECK() to make it easier to convert to a
- * specific type:
- *
- * .. kernel-doc messes up with the code block below because of the
- * backslash at the end of lines. This will be fixes if we move this
- * content to qom.rst.
- *
- * .. code-block:: c
- * :caption: Typecasting macros
- *
- * #define MY_DEVICE_GET_CLASS(obj) \
- * OBJECT_GET_CLASS(MyDeviceClass, obj, TYPE_MY_DEVICE)
- * #define MY_DEVICE_CLASS(klass) \
- * OBJECT_CLASS_CHECK(MyDeviceClass, klass, TYPE_MY_DEVICE)
- * #define MY_DEVICE(obj) \
- * OBJECT_CHECK(MyDevice, obj, TYPE_MY_DEVICE)
- *
- * Class Initialization
- * ====================
- *
- * Before an object is initialized, the class for the object must be
- * initialized. There is only one class object for all instance objects
- * that is created lazily.
- *
- * Classes are initialized by first initializing any parent classes (if
- * necessary). After the parent class object has initialized, it will be
- * copied into the current class object and any additional storage in the
- * class object is zero filled.
- *
- * The effect of this is that classes automatically inherit any virtual
- * function pointers that the parent class has already initialized. All
- * other fields will be zero filled.
- *
- * Once all of the parent classes have been initialized, #TypeInfo::class_init
- * is called to let the class being instantiated provide default initialize for
- * its virtual functions. Here is how the above example might be modified
- * to introduce an overridden virtual function:
- *
- * .. code-block:: c
- * :caption: Overriding a virtual function
- *
- * #include "qdev.h"
- *
- * void my_device_class_init(ObjectClass *klass, void *class_data)
- * {
- * DeviceClass *dc = DEVICE_CLASS(klass);
- * dc->reset = my_device_reset;
- * }
- *
- * static const TypeInfo my_device_info = {
- * .name = TYPE_MY_DEVICE,
- * .parent = TYPE_DEVICE,
- * .instance_size = sizeof(MyDevice),
- * .class_init = my_device_class_init,
- * };
- *
- * Introducing new virtual methods requires a class to define its own
- * struct and to add a .class_size member to the #TypeInfo. Each method
- * will also have a wrapper function to call it easily:
- *
- * .. code-block:: c
- * :caption: Defining an abstract class
- *
- * #include "qdev.h"
- *
- * typedef struct MyDeviceClass
- * {
- * DeviceClass parent;
- *
- * void (*frobnicate) (MyDevice *obj);
- * } MyDeviceClass;
- *
- * static const TypeInfo my_device_info = {
- * .name = TYPE_MY_DEVICE,
- * .parent = TYPE_DEVICE,
- * .instance_size = sizeof(MyDevice),
- * .abstract = true, // or set a default in my_device_class_init
- * .class_size = sizeof(MyDeviceClass),
- * };
- *
- * void my_device_frobnicate(MyDevice *obj)
- * {
- * MyDeviceClass *klass = MY_DEVICE_GET_CLASS(obj);
- *
- * klass->frobnicate(obj);
- * }
- *
- * Interfaces
- * ==========
- *
- * Interfaces allow a limited form of multiple inheritance. Instances are
- * similar to normal types except for the fact that are only defined by
- * their classes and never carry any state. As a consequence, a pointer to
- * an interface instance should always be of incomplete type in order to be
- * sure it cannot be dereferenced. That is, you should define the
- * 'typedef struct SomethingIf SomethingIf' so that you can pass around
- * ``SomethingIf *si`` arguments, but not define a ``struct SomethingIf { ... }``.
- * The only things you can validly do with a ``SomethingIf *`` are to pass it as
- * an argument to a method on its corresponding SomethingIfClass, or to
- * dynamically cast it to an object that implements the interface.
- *
- * Methods
- * =======
- *
- * A <emphasis>method</emphasis> is a function within the namespace scope of
- * a class. It usually operates on the object instance by passing it as a
- * strongly-typed first argument.
- * If it does not operate on an object instance, it is dubbed
- * <emphasis>class method</emphasis>.
- *
- * Methods cannot be overloaded. That is, the #ObjectClass and method name
- * uniquely identity the function to be called; the signature does not vary
- * except for trailing varargs.
- *
- * Methods are always <emphasis>virtual</emphasis>. Overriding a method in
- * #TypeInfo.class_init of a subclass leads to any user of the class obtained
- * via OBJECT_GET_CLASS() accessing the overridden function.
- * The original function is not automatically invoked. It is the responsibility
- * of the overriding class to determine whether and when to invoke the method
- * being overridden.
- *
- * To invoke the method being overridden, the preferred solution is to store
- * the original value in the overriding class before overriding the method.
- * This corresponds to ``{super,base}.method(...)`` in Java and C#
- * respectively; this frees the overriding class from hardcoding its parent
- * class, which someone might choose to change at some point.
- *
- * .. code-block:: c
- * :caption: Overriding a virtual method
- *
- * typedef struct MyState MyState;
- *
- * typedef void (*MyDoSomething)(MyState *obj);
- *
- * typedef struct MyClass {
- * ObjectClass parent_class;
- *
- * MyDoSomething do_something;
- * } MyClass;
- *
- * static void my_do_something(MyState *obj)
- * {
- * // do something
- * }
- *
- * static void my_class_init(ObjectClass *oc, void *data)
- * {
- * MyClass *mc = MY_CLASS(oc);
- *
- * mc->do_something = my_do_something;
- * }
- *
- * static const TypeInfo my_type_info = {
- * .name = TYPE_MY,
- * .parent = TYPE_OBJECT,
- * .instance_size = sizeof(MyState),
- * .class_size = sizeof(MyClass),
- * .class_init = my_class_init,
- * };
- *
- * typedef struct DerivedClass {
- * MyClass parent_class;
- *
- * MyDoSomething parent_do_something;
- * } DerivedClass;
- *
- * static void derived_do_something(MyState *obj)
- * {
- * DerivedClass *dc = DERIVED_GET_CLASS(obj);
- *
- * // do something here
- * dc->parent_do_something(obj);
- * // do something else here
- * }
- *
- * static void derived_class_init(ObjectClass *oc, void *data)
- * {
- * MyClass *mc = MY_CLASS(oc);
- * DerivedClass *dc = DERIVED_CLASS(oc);
- *
- * dc->parent_do_something = mc->do_something;
- * mc->do_something = derived_do_something;
- * }
- *
- * static const TypeInfo derived_type_info = {
- * .name = TYPE_DERIVED,
- * .parent = TYPE_MY,
- * .class_size = sizeof(DerivedClass),
- * .class_init = derived_class_init,
- * };
- *
- * Alternatively, object_class_by_name() can be used to obtain the class and
- * its non-overridden methods for a specific type. This would correspond to
- * ``MyClass::method(...)`` in C++.
- *
- * The first example of such a QOM method was #CPUClass.reset,
- * another example is #DeviceClass.realize.
- *
- * Standard type declaration and definition macros
- * ===============================================
- *
- * A lot of the code outlined above follows a standard pattern and naming
- * convention. To reduce the amount of boilerplate code that needs to be
- * written for a new type there are two sets of macros to generate the
- * common parts in a standard format.
- *
- * A type is declared using the OBJECT_DECLARE macro family. In types
- * which do not require any virtual functions in the class, the
- * OBJECT_DECLARE_SIMPLE_TYPE macro is suitable, and is commonly placed
- * in the header file:
- *
- * .. code-block:: c
- * :caption: Declaring a simple type
- *
- * OBJECT_DECLARE_SIMPLE_TYPE(MyDevice, my_device, MY_DEVICE, DEVICE)
- *
- * This is equivalent to the following:
- *
- * .. code-block:: c
- * :caption: Expansion from declaring a simple type
- *
- * typedef struct MyDevice MyDevice;
- * typedef struct MyDeviceClass MyDeviceClass;
- *
- * G_DEFINE_AUTOPTR_CLEANUP_FUNC(MyDeviceClass, object_unref)
- *
- * #define MY_DEVICE_GET_CLASS(void *obj) \
- * OBJECT_GET_CLASS(MyDeviceClass, obj, TYPE_MY_DEVICE)
- * #define MY_DEVICE_CLASS(void *klass) \
- * OBJECT_CLASS_CHECK(MyDeviceClass, klass, TYPE_MY_DEVICE)
- * #define MY_DEVICE(void *obj)
- * OBJECT_CHECK(MyDevice, obj, TYPE_MY_DEVICE)
- *
- * struct MyDeviceClass {
- * DeviceClass parent_class;
- * };
- *
- * The 'struct MyDevice' needs to be declared separately.
- * If the type requires virtual functions to be declared in the class
- * struct, then the alternative OBJECT_DECLARE_TYPE() macro can be
- * used. This does the same as OBJECT_DECLARE_SIMPLE_TYPE(), but without
- * the 'struct MyDeviceClass' definition.
- *
- * To implement the type, the OBJECT_DEFINE macro family is available.
- * In the simple case the OBJECT_DEFINE_TYPE macro is suitable:
- *
- * .. code-block:: c
- * :caption: Defining a simple type
- *
- * OBJECT_DEFINE_TYPE(MyDevice, my_device, MY_DEVICE, DEVICE)
- *
- * This is equivalent to the following:
- *
- * .. code-block:: c
- * :caption: Expansion from defining a simple type
- *
- * static void my_device_finalize(Object *obj);
- * static void my_device_class_init(ObjectClass *oc, void *data);
- * static void my_device_init(Object *obj);
- *
- * static const TypeInfo my_device_info = {
- * .parent = TYPE_DEVICE,
- * .name = TYPE_MY_DEVICE,
- * .instance_size = sizeof(MyDevice),
- * .instance_init = my_device_init,
- * .instance_finalize = my_device_finalize,
- * .class_size = sizeof(MyDeviceClass),
- * .class_init = my_device_class_init,
- * };
- *
- * static void
- * my_device_register_types(void)
- * {
- * type_register_static(&my_device_info);
- * }
- * type_init(my_device_register_types);
- *
- * This is sufficient to get the type registered with the type
- * system, and the three standard methods now need to be implemented
- * along with any other logic required for the type.
- *
- * If the type needs to implement one or more interfaces, then the
- * OBJECT_DEFINE_TYPE_WITH_INTERFACES() macro can be used instead.
- * This accepts an array of interface type names.
- *
- * .. code-block:: c
- * :caption: Defining a simple type implementing interfaces
- *
- * OBJECT_DEFINE_TYPE_WITH_INTERFACES(MyDevice, my_device,
- * MY_DEVICE, DEVICE,
- * { TYPE_USER_CREATABLE }, { NULL })
- *
- * If the type is not intended to be instantiated, then then
- * the OBJECT_DEFINE_ABSTRACT_TYPE() macro can be used instead:
- *
- * .. code-block:: c
- * :caption: Defining a simple abstract type
- *
- * OBJECT_DEFINE_ABSTRACT_TYPE(MyDevice, my_device, MY_DEVICE, DEVICE)
- */
-
-
typedef struct ObjectProperty ObjectProperty;
/**
projects / mirror_qemu.git / blobdiff