jvm源码解读--10 enum WKID 枚举

时间:2022-02-03 01:38:52

源码中对于枚举类型WKID的使用

  static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
int limit = (int)end_id + 1;
initialize_wk_klasses_until((WKID) limit, start_id, THREAD);

这个是宏定义,类似于以下简码

int main() {
enum EM{
day1,b1=day1,
day2,b2=day2, }; std::cout << "day2的值为:" << std::endl;
std::cout << EM::day2 << std::endl;
std::cout << "b1 的值为:" << std::endl;
std::cout << EM::b1 << std::endl;
return 0;
}
打印结果
day2的值为:
1
b1 的值为:
0

能看出来,这个枚举非常特殊,

那么看WKID

enum WKID {
NO_WKID = 0,
/* well-known classes */
Object_klass_knum, java_lang_Object_knum = Object_klass_knum,
String_klass_knum, java_lang_String_knum = String_klass_knum,
Class_klass_knum, java_lang_Class_knum = Class_klass_knum,
Cloneable_klass_knum, java_lang_Cloneable_knum = Cloneable_klass_knum,
ClassLoader_klass_knum, java_lang_ClassLoader_knum = Cloneable_klass_knum,
Serializable_klass_knum, java_io_Serializable_knum = Serializable_klass_knum,
System_klass_knum, java_lang_System_knum = System_klass_knum,
Throwable_klass_knum, java_lang_Throwable_knum = Throwable_klass_knum,
Error_klass_knum, java_lang_Error_knum = Error_klass_knum,
ThreadDeath_klass_knum, java_lang_ThreadDeath_knum = ThreadDeath_klass_knum,
Exception_klass_knum, java_lang_Exception_knum = Exception_klass_knum,,
RuntimeException_klass_knum, java_lang_RuntimeException_knum = RuntimeException_klass_knum,
SecurityManager_klass_knum, java_lang_SecurityManager_knum = SecurityManager_klass_knum,
ProtectionDomain_klass_knum, java_security_ProtectionDomain_knum = ProtectionDomain_klass_knum,
AccessControlContext_klass_knum, java_security_AccessControlContext_knum = AccessControlContext_klass_knum,
ClassNotFoundException_klass_knum, java_lang_ClassNotFoundException_knum = ClassNotFoundException_klass_knum,
NoClassDefFoundError_klass_knum, java_lang_NoClassDefFoundError_knum = NoClassDefFoundError_klass_knum,
LinkageError_klass_knum, java_lang_LinkageError_knum = LinkageError_klass_knum,
ClassCastException_klass_knum, java_lang_ClassCastException_knum = ClassCastException_klass_knum,
ArrayStoreException_klass_knum, java_lang_ArrayStoreException_knum = ArrayStoreException_klass_knum,
VirtualMachineError_klass_knum, java_lang_VirtualMachineError_knum = VirtualMachineError_klass_knum,
OutOfMemoryError_klass_knum, java_lang_OutOfMemoryError_knum = OutOfMemoryError_klass_knum,
*Error_klass_knum, java_lang_*Error_knum = *Error_klass_knum,
IllegalMonitorStateException_klass_knum, java_lang_IllegalMonitorStateException_knum = IllegalMonitorStateException_klass_knum,
Reference_klass_knum, java_lang_ref_Reference_knum = Reference_klass_knum, /* load ref klasses and set reference types */
SoftReference_klass_knum, java_lang_ref_SoftReference_knum = SoftReference_klass_knum,
WeakReference_klass_knum, java_lang_ref_WeakReference_knum = WeakReference_klass_knum,
FinalReference_klass_knum, java_lang_ref_FinalReference_knum = FinalReference_klass_knum,
PhantomReference_klass_knum, java_lang_ref_PhantomReference_knum = PhantomReference_klass_knum,
Finalizer_klass_knum, java_lang_ref_Finalizer_knum = Finalizer_klass_knum, Thread_klass_knum, java_lang_Thread_knum = Thread_klass_knum,
ThreadGroup_klass_knum, java_lang_ThreadGroup_knum = ThreadGroup_klass_knum,
Properties_klass_knum, java_util_Properties_knum = Properties_klass_knum,
reflect_AccessibleObject_klass_knum, java_lang_reflect_AccessibleObject_knum = reflect_AccessibleObject_klass_knum,
reflect_Field_klass_knum, java_lang_reflect_Field_knum = reflect_Field_klass_knum,
reflect_Parameter_klass_knum, java_lang_reflect_Parameter_knum = reflect_Parameter_klass_knum,
reflect_Method_klass_knum, java_lang_reflect_Method_knum = reflect_Method_klass_knum,
reflect_Constructor_klass_knum, java_lang_reflect_Constructor_knum = reflect_Constructor_klass_knum, /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */
/* Universe::is_gte_jdk14x_version( is not set up by this point. */
/* It's okay if this turns out to be NULL in non-1.4 JDKs. */
reflect_MagicAccessorImpl_klass_knum, sun_reflect_MagicAccessorImpl_knum = reflect_MagicAccessorImpl_klass_knum,
reflect_MethodAccessorImpl_klass_knum, sun_reflect_MethodAccessorImpl_knum = reflect_MethodAccessorImpl_klass_knum,
reflect_ConstructorAccessorImpl_klass_knum, sun_reflect_ConstructorAccessorImpl_knum = reflect_ConstructorAccessorImpl_klass_knum,
reflect_DelegatingClassLoader_klass_knum, sun_reflect_DelegatingClassLoader_knum = reflect_DelegatingClassLoader_klass_knum,
reflect_ConstantPool_klass_knum, sun_reflect_ConstantPool_knum = reflect_ConstantPool_klass_knum,
reflect_UnsafeStaticFieldAccessorImpl_klass_knum, sun_reflect_UnsafeStaticFieldAccessorImpl_knum = reflect_UnsafeStaticFieldAccessorImpl_klass_knum,
reflect_CallerSensitive_klass_knum, sun_reflect_CallerSensitive_knum = reflect_CallerSensitive_klass_knum, /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */
DirectMethodHandle_klass_knum, java_lang_invoke_DirectMethodHandle_knum = DirectMethodHandle_klass_knum,
MethodHandle_klass_knum, java_lang_invoke_MethodHandle_knum = MethodHandle_klass_knum,
MemberName_klass_knum, java_lang_invoke_MemberName_knum = MemberName_klass_knum,
MethodHandleNatives_klass_knum, java_lang_invoke_MethodHandleNatives_knum = MethodHandleNatives_klass_knum,
LambdaForm_klass_knum, java_lang_invoke_LambdaForm_knum = LambdaForm_klass_knum,
MethodType_klass_knum, java_lang_invoke_MethodType_knum = MethodType_klass_knum,
BootstrapMethodError_klass_knum, java_lang_BootstrapMethodError_knum = BootstrapMethodError_klass_knum,
CallSite_klass_knum, java_lang_invoke_CallSite_knum = CallSite_klass_knum,
ConstantCallSite_klass_knum, java_lang_invoke_ConstantCallSite_knum = ConstantCallSite_klass_knum,
MutableCallSite_klass_knum, java_lang_invoke_MutableCallSite_knum = MutableCallSite_klass_knum,
VolatileCallSite_klass_knum, java_lang_invoke_VolatileCallSite_knum = VolatileCallSite_klass_knum,
/* Note: MethodHandle must be first, and VolatileCallSite last in group */ StringBuffer_klass_knum, java_lang_StringBuffer_knum = StringBuffer_klass_knum,
StringBuilder_klass_knum, java_lang_StringBuilder_knum = StringBuilder_klass_knum,
misc_Unsafe_klass_knum, sun_misc_Unsafe_knum = misc_Unsafe_klass_knum, /* It's NULL in non-1.4 JDKs. */
StackTraceElement_klass_knum, java_lang_StackTraceElement_knum = StackTraceElement_klass_knum,
/* Universe::is_gte_jdk14x_version( is not set up by this point. */
/* It's okay if this turns out to be NULL in non-1.4 JDKs. */
nio_Buffer_klass_knum, java_nio_Buffer_knum = nio_Buffer_klass_knum, /* load boxing klasses */
Boolean_klass_knum, java_lang_Boolean_knum = Boolean_klass_knum,
Character_klass_knum, java_lang_Character_knum = Character_klass_knum,
Float_klass_knum, java_lang_Float_knum = Float_klass_knum,
Double_klass_knum, java_lang_Double_knum = Double_klass_knum,
Byte_klass_knum, java_lang_Byte_knum = Byte_klass_knum,
Short_klass_knum, java_lang_Short_knum = Short_klass_knum,
Integer_klass_knum, java_lang_Integer_knum = Integer_klass_knum,
Long_klass_knum, java_lang_Long_knum = Long_klass_knum, //68
/*end*/
WKID_LIMIT, //69 FIRST_WKID = NO_WKID + 1
};

这个宏是之前是看不懂的,今天顺利的解决了,通过clion的replace R 功能,替换,先将代码写道一个cpp文件中,全部替换就行了

 public:
enum WKID {
NO_WKID = 0, #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),
WK_KLASSES_DO(WK_KLASS_ENUM)
#undef WK_KLASS_ENUM WKID_LIMIT, FIRST_WKID = NO_WKID + 1
};

这里非常重要的是

#define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),
//

这个一行看成两部分,用  空格作为区分