深入了解Golang interface{}的底层原理实现

type Test interface{
    test()
}

//runtime/runtime2.go

//非空接口
type iface struct {
	tab  *itab
	data unsafe.Pointer //data是指向真实数据的指针
}
type itab struct {
	inter  *interfacetype //描述接口自己的类型
	_type  *_type         //接口内部存储的具体数据的真实类型
	link   *itab
	hash   uint32 // copy of _type.hash. Used for type switches.
	bad    bool   // type does not implement interface
	inhash bool   // has this itab been added to hash?
	unused [2]byte
	fun    [1]uintptr // fun是指向方法集的指针。它用于动态调度。
}

//runtime/type.go
type _type struct {
	size       uintptr
	ptrdata    uintptr // size of memory prefix holding all pointers
	hash       uint32
	tflag      tflag
	align      uint8
	fieldalign uint8
	kind       uint8
	alg        *typeAlg
	// gcdata stores the GC type data for the garbage collector.
	// If the KindGCProg bit is set in kind, gcdata is a GC program.
	// Otherwise it is a ptrmask bitmap. See mbitmap.go for details.
	gcdata    *byte
	str       nameOff
	ptrToThis typeOff
}

type Test interface {}

//空接口
type eface struct {
	_type *_type         //接口内部存储的具体数据的真实类型
	data  unsafe.Pointer //data是指向真实数据的指针
}

//runtime/type.go
type _type struct {
	size       uintptr
	ptrdata    uintptr // size of memory prefix holding all pointers
	hash       uint32
	tflag      tflag
	align      uint8
	fieldalign uint8
	kind       uint8
	alg        *typeAlg
	// gcdata stores the GC type data for the garbage collector.
	// If the KindGCProg bit is set in kind, gcdata is a GC program.
	// Otherwise it is a ptrmask bitmap. See mbitmap.go for details.
	gcdata    *byte
	str       nameOff
	ptrToThis typeOff
}