runtime系列--基本数据类型

一、runtime基本数据类型

1、实例变量

/// An opaque type that represents an instance variable. typedef struct objc_ivar *Ivar;

2、属性

/// An opaque type that represents an Objective-C declared property. typedef struct objc_property *objc_property_t;

3、类的实例

/// Represents an instance of a class. struct objc_object { Class _Nonnull isa OBJC_ISA_AVAILABILITY; }; /// A pointer to an instance of a class.指向类的实例的指针 typedef struct objc_object *id;

4、Objective-C中的类

//Objective-C2.0版本之后，类的定义如下 struct objc_class : objc_object { // Class ISA; Class superclass; cache_t cache; // formerly cache pointer and vtable class_data_bits_t bits; // class_rw_t * plus custom rr/alloc flags ...... } /// An opaque type that represents an Objective-C class. typedef struct objc_class *Class;

5、分类

/// An opaque type that represents a category. typedef struct objc_category *Category;

6、函数方法

/// An opaque type that represents a method in a class definition. typedef struct objc_method *Method;

二、详细介绍对象和类

1、对象

struct objc_object { private: isa_t isa;//isa指针 public: // ISA() assumes this is NOT a tagged pointer object Class ISA(); // getIsa() allows this to be a tagged pointer object Class getIsa(); // initIsa() should be used to init the isa of new objects only. // If this object already has an isa, use changeIsa() for correctness. // initInstanceIsa(): objects with no custom RR/AWZ // initClassIsa(): class objects // initProtocolIsa(): protocol objects // initIsa(): other objects void initIsa(Class cls /*nonpointer=false*/); void initClassIsa(Class cls /*nonpointer=maybe*/); void initProtocolIsa(Class cls /*nonpointer=maybe*/); void initInstanceIsa(Class cls, bool hasCxxDtor); // changeIsa() should be used to change the isa of existing objects. // If this is a new object, use initIsa() for performance. Class changeIsa(Class newCls); bool hasNonpointerIsa(); bool isTaggedPointer(); bool isBasicTaggedPointer(); bool isExtTaggedPointer(); bool isClass(); // object may have associated objects? bool hasAssociatedObjects(); void setHasAssociatedObjects(); // object may be weakly referenced? bool isWeaklyReferenced(); void setWeaklyReferenced_nolock(); // object may have -.cxx_destruct implementation? bool hasCxxDtor(); // Optimized calls to retain/release methods id retain(); void release(); id autorelease(); // Implementations of retain/release methods id rootRetain(); bool rootRelease(); id rootAutorelease(); bool rootTryRetain(); bool rootReleaseShouldDealloc(); uintptr_t rootRetainCount(); // Implementation of dealloc methods bool rootIsDeallocating(); void clearDeallocating(); void rootDealloc(); private: void initIsa(Class newCls, bool nonpointer, bool hasCxxDtor); // Slow paths for inline control id rootAutorelease2(); bool overrelease_error(); #if SUPPORT_NONPOINTER_ISA // Unified retain count manipulation for nonpointer isa id rootRetain(bool tryRetain, bool handleOverflow); bool rootRelease(bool performDealloc, bool handleUnderflow); id rootRetain_overflow(bool tryRetain); bool rootRelease_underflow(bool performDealloc); void clearDeallocating_slow(); // Side table retain count overflow for nonpointer isa void sidetable_lock(); void sidetable_unlock(); void sidetable_moveExtraRC_nolock(size_t extra_rc, bool isDeallocating, bool weaklyReferenced); bool sidetable_addExtraRC_nolock(size_t delta_rc); size_t sidetable_subExtraRC_nolock(size_t delta_rc); size_t sidetable_getExtraRC_nolock(); #endif // Side-table-only retain count bool sidetable_isDeallocating(); void sidetable_clearDeallocating(); bool sidetable_isWeaklyReferenced(); void sidetable_setWeaklyReferenced_nolock(); id sidetable_retain(); id sidetable_retain_slow(SideTable& table); uintptr_t sidetable_release(bool performDealloc = true); uintptr_t sidetable_release_slow(SideTable& table, bool performDealloc = true); bool sidetable_tryRetain(); uintptr_t sidetable_retainCount(); #if DEBUG bool sidetable_present(); #endif }