上代码
package test;
/**
* @author Ye-Ma
* @Description TODO
* @date 2022/1/7-11:13
*/
public class InitDeadLock {
public static void main(String[] args) {
new Thread(() -> new AA()).start();
new Thread(() -> new BB()).start();
}
}
class AA {
static {
System.out.println("Class A init");
new BB();
}
}
class BB {
static {
System.out.println("Class B init");
new AA();
}
}
字节码
Classfile /D:/JavaClass/jucDemo/target/classes/test/InitDeadLock.class
Last modified 2022-1-7; size 1183 bytes
MD5 checksum b2b640931bdf6721e880f1f024e0a39b
Compiled from "InitDeadLock.java"
public class test.InitDeadLock
minor version: 0
major version: 52
flags: ACC_PUBLIC, ACC_SUPER
Constant pool:
#1 = Methodref #12.#28 // java/lang/Object."<init>":()V
#2 = Class #29 // java/lang/Thread
#3 = InvokeDynamic #0:#34 // #0:run:()Ljava/lang/Runnable;
#4 = Methodref #2.#35 // java/lang/Thread."<init>":(Ljava/lang/Runnable;)V
#5 = Methodref #2.#36 // java/lang/Thread.start:()V
#6 = InvokeDynamic #1:#34 // #1:run:()Ljava/lang/Runnable;
#7 = Class #38 // test/BB
#8 = Methodref #7.#28 // test/BB."<init>":()V
#9 = Class #39 // test/AA
#10 = Methodref #9.#28 // test/AA."<init>":()V
#11 = Class #40 // test/InitDeadLock
#12 = Class #41 // java/lang/Object
#13 = Utf8 <init>
#14 = Utf8 ()V
#15 = Utf8 Code
#16 = Utf8 LineNumberTable
#17 = Utf8 LocalVariableTable
#18 = Utf8 this
#19 = Utf8 Ltest/InitDeadLock;
#20 = Utf8 main
#21 = Utf8 ([Ljava/lang/String;)V
#22 = Utf8 args
#23 = Utf8 [Ljava/lang/String;
#24 = Utf8 lambda$main$1
#25 = Utf8 lambda$main$0
#26 = Utf8 SourceFile
#27 = Utf8 InitDeadLock.java
#28 = NameAndType #13:#14 // "<init>":()V
#29 = Utf8 java/lang/Thread
#30 = Utf8 BootstrapMethods
#31 = MethodHandle #6:#42 // invokestatic java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#32 = MethodType #14 // ()V
#33 = MethodHandle #6:#43 // invokestatic test/InitDeadLock.lambda$main$0:()V
#34 = NameAndType #44:#45 // run:()Ljava/lang/Runnable;
#35 = NameAndType #13:#46 // "<init>":(Ljava/lang/Runnable;)V
#36 = NameAndType #47:#14 // start:()V
#37 = MethodHandle #6:#48 // invokestatic test/InitDeadLock.lambda$main$1:()V
#38 = Utf8 test/BB
#39 = Utf8 test/AA
#40 = Utf8 test/InitDeadLock
#41 = Utf8 java/lang/Object
#42 = Methodref #49.#50 // java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#43 = Methodref #11.#51 // test/InitDeadLock.lambda$main$0:()V
#44 = Utf8 run
#45 = Utf8 ()Ljava/lang/Runnable;
#46 = Utf8 (Ljava/lang/Runnable;)V
#47 = Utf8 start
#48 = Methodref #11.#52 // test/InitDeadLock.lambda$main$1:()V
#49 = Class #53 // java/lang/invoke/LambdaMetafactory
#50 = NameAndType #54:#58 // metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#51 = NameAndType #25:#14 // lambda$main$0:()V
#52 = NameAndType #24:#14 // lambda$main$1:()V
#53 = Utf8 java/lang/invoke/LambdaMetafactory
#54 = Utf8 metafactory
#55 = Class #60 // java/lang/invoke/MethodHandles$Lookup
#56 = Utf8 Lookup
#57 = Utf8 InnerClasses
#58 = Utf8 (Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#59 = Class #61 // java/lang/invoke/MethodHandles
#60 = Utf8 java/lang/invoke/MethodHandles$Lookup
#61 = Utf8 java/lang/invoke/MethodHandles
{
public test.InitDeadLock();
descriptor: ()V
flags: ACC_PUBLIC
Code:
stack=1, locals=1, args_size=1
0: aload_0
1: invokespecial #1 // Method java/lang/Object."<init>":()V
4: return
LineNumberTable:
line 8: 0
LocalVariableTable:
Start Length Slot Name Signature
0 5 0 this Ltest/InitDeadLock;
public static void main(java.lang.String[]);
descriptor: ([Ljava/lang/String;)V
flags: ACC_PUBLIC, ACC_STATIC
Code:
stack=3, locals=1, args_size=1
0: new #2 // class java/lang/Thread
3: dup
4: invokedynamic #3, 0 // InvokeDynamic #0:run:()Ljava/lang/Runnable;
9: invokespecial #4 // Method java/lang/Thread."<init>":(Ljava/lang/Runnable;)V
12: invokevirtual #5 // Method java/lang/Thread.start:()V
15: new #2 // class java/lang/Thread
18: dup
19: invokedynamic #6, 0 // InvokeDynamic #1:run:()Ljava/lang/Runnable;
24: invokespecial #4 // Method java/lang/Thread."<init>":(Ljava/lang/Runnable;)V
27: invokevirtual #5 // Method java/lang/Thread.start:()V
30: return
LineNumberTable:
line 10: 0
line 11: 15
line 12: 30
LocalVariableTable:
Start Length Slot Name Signature
0 31 0 args [Ljava/lang/String;
private static void lambda$main$1();
descriptor: ()V
flags: ACC_PRIVATE, ACC_STATIC, ACC_SYNTHETIC
Code:
stack=2, locals=0, args_size=0
0: new #7 // class test/BB
3: dup
4: invokespecial #8 // Method test/BB."<init>":()V
7: pop
8: return
LineNumberTable:
line 11: 0
private static void lambda$main$0();
descriptor: ()V
flags: ACC_PRIVATE, ACC_STATIC, ACC_SYNTHETIC
Code:
stack=2, locals=0, args_size=0
0: new #9 // class test/AA
3: dup
4: invokespecial #10 // Method test/AA."<init>":()V
7: pop
8: return
LineNumberTable:
line 10: 0
}
SourceFile: "InitDeadLock.java"
InnerClasses:
public static final #56= #55 of #59; //Lookup=class java/lang/invoke/MethodHandles$Lookup of class java/lang/invoke/MethodHandles
BootstrapMethods:
0: #31 invokestatic java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
Method arguments:
#32 ()V
#33 invokestatic test/InitDeadLock.lambda$main$0:()V
#32 ()V
1: #31 invokestatic java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
Method arguments:
#32 ()V
#37 invokestatic test/InitDeadLock.lambda$main$1:()V
#32 ()V
名称: RMI TCP Connection(3)-192.168.196.138
状态: RUNNABLE
总阻止数: 1, 总等待数: 0
堆栈跟踪:
sun.management.ThreadImpl.dumpThreads0(Native Method)
sun.management.ThreadImpl.dumpAllThreads(ThreadImpl.java:496)
sun.management.ThreadImpl.dumpAllThreads(ThreadImpl.java:484)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
sun.reflect.misc.Trampoline.invoke(MethodUtil.java:72)
sun.reflect.GeneratedMethodAccessor8.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:276)
com.sun.jmx.mbeanserver.ConvertingMethod.invokeWithOpenReturn(ConvertingMethod.java:193)
com.sun.jmx.mbeanserver.ConvertingMethod.invokeWithOpenReturn(ConvertingMethod.java:175)
com.sun.jmx.mbeanserver.MXBeanIntrospector.invokeM2(MXBeanIntrospector.java:117)
com.sun.jmx.mbeanserver.MXBeanIntrospector.invokeM2(MXBeanIntrospector.java:54)
com.sun.jmx.mbeanserver.MBeanIntrospector.invokeM(MBeanIntrospector.java:237)
com.sun.jmx.mbeanserver.PerInterface.invoke(PerInterface.java:138)
com.sun.jmx.mbeanserver.MBeanSupport.invoke(MBeanSupport.java:252)
javax.management.StandardMBean.invoke(StandardMBean.java:405)
com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1468)
javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76)
javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1309)
javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1401)
javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829)
检测不出死锁的情况
认识一下javac,将远代码转变为字节码
Java的执行过程整体可以分为两个部分，第一步由javac将源码编译成字节码，在这个过程中会进行词法分析、语法分析、语义分析，编译原理中这部分的编译称为前端编译。接下来无需编译直接逐条将字节码解释执行，在解释执行的过程中，虚拟机同时对程序运行的信息进行收集，在这些信息的基础上，编译器会逐渐发挥作用，它会进行后端编译——把字节码编译成机器码，但不是所有的代码都会被编译，只有被JVM认定为的热点代码，才可能被编译。
编译器
JVM中集成了两种编译器，Client Compiler和Server Compiler，
Client Compiler: 注重启动速度和局部的优化
HotSpot VM带有一个Client Compiler C1编译器。这种编译器启动速度快，但是性能比较Server Compiler来说会差一些。C1会做三件事：
Server Compiler: 更加关注全局的优化，性能会更好
Server Compiler主要关注一些编译耗时较长的全局优化，甚至会还会根据程序运行的信息进行一些不可靠的激进优化。这种编译器的启动时间长，适用于长时间运行的后台程序，它的性能通常比Client Compiler高30%以上。目前，Hotspot虚拟机中使用的Server Compiler有两种：C2和Graal。
src\share\classes\sun\tools\javac
静态变量
Java对象模型: OOP-Klass模型
在JVM中，并没有直接将Java对象映射成C++对象，而是采用了oop-klass模型，主要是不希望每个对象中都包含有一份虚函数表，其中：
** OOP(Ordinary Object Point)，表示对象的实例信息**
** Klass，是Java类的在C++中的表示，用来描述Java类的信息**
简单地说，一个Java类在JVM中被拆分为了两个部分：数据和描述信息，分别对应OOP和Klass。
在具体的JVM源码中，当加载一个Class时，会创建一个InstanceKlass对象，实例化的对象则对应InstanceOopDesc，其中InstanceKlass存放在元空间，InstanceOopDesc存放在堆中。
HotSpot类模型之InstanceKlass
**InstanceKlass.cpp **
instanceKlass.cpp
/*
* Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "classfile/javaClasses.hpp"
#include "classfile/systemDictionary.hpp"
#include "classfile/systemDictionaryShared.hpp"
#include "classfile/verifier.hpp"
#include "classfile/vmSymbols.hpp"
#include "compiler/compileBroker.hpp"
#include "gc_implementation/shared/markSweep.inline.hpp"
#include "gc_interface/collectedHeap.inline.hpp"
#include "interpreter/oopMapCache.hpp"
#include "interpreter/rewriter.hpp"
#include "jvmtifiles/jvmti.h"
#include "memory/genOopClosures.inline.hpp"
#include "memory/heapInspection.hpp"
#include "memory/iterator.inline.hpp"
#include "memory/metadataFactory.hpp"
#include "memory/oopFactory.hpp"
#include "oops/fieldStreams.hpp"
#include "oops/instanceClassLoaderKlass.hpp"
#include "oops/instanceKlass.hpp"
#include "oops/instanceMirrorKlass.hpp"
#include "oops/instanceOop.hpp"
#include "oops/klass.inline.hpp"
#include "oops/method.hpp"
#include "oops/oop.inline.hpp"
#include "oops/symbol.hpp"
#include "prims/jvmtiExport.hpp"
#include "prims/jvmtiRedefineClassesTrace.hpp"
#include "prims/jvmtiRedefineClasses.hpp"
#include "prims/jvmtiThreadState.hpp"
#include "prims/methodComparator.hpp"
#include "runtime/fieldDescriptor.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/orderAccess.inline.hpp"
#include "runtime/thread.inline.hpp"
#include "services/classLoadingService.hpp"
#include "services/threadService.hpp"
#include "utilities/dtrace.hpp"
#include "utilities/macros.hpp"
#if INCLUDE_ALL_GCS
#include "gc_implementation/concurrentMarkSweep/cmsOopClosures.inline.hpp"
#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
#include "gc_implementation/g1/g1OopClosures.inline.hpp"
#include "gc_implementation/g1/g1RemSet.inline.hpp"
#include "gc_implementation/g1/heapRegionManager.inline.hpp"
#include "gc_implementation/parNew/parOopClosures.inline.hpp"
#include "gc_implementation/parallelScavenge/parallelScavengeHeap.inline.hpp"
#include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
#include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
#include "oops/oop.pcgc.inline.hpp"
#endif // INCLUDE_ALL_GCS
#ifdef COMPILER1
#include "c1/c1_Compiler.hpp"
#endif
#if INCLUDE_JFR
#include "jfr/jfrEvents.hpp"
#endif
PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
#ifdef DTRACE_ENABLED
#ifndef USDT2
HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required,
char*, intptr_t, oop, intptr_t);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive,
char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent,
char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous,
char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed,
char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit,
char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error,
char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end,
char*, intptr_t, oop, intptr_t, int);
#define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) \
{ \
char* data = NULL; \
int len = 0; \
Symbol* name = (clss)->name(); \
if (name != NULL) { \
data = (char*)name->bytes(); \
len = name->utf8_length(); \
} \
HS_DTRACE_PROBE4(hotspot, class__initialization__##type, \
data, len, (void *)(clss)->class_loader(), thread_type); \
}
#define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
{ \
char* data = NULL; \
int len = 0; \
Symbol* name = (clss)->name(); \
if (name != NULL) { \
data = (char*)name->bytes(); \
len = name->utf8_length(); \
} \
HS_DTRACE_PROBE5(hotspot, class__initialization__##type, \
data, len, (void *)(clss)->class_loader(), thread_type, wait); \
}
#else /* USDT2 */
#define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
#define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
#define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
#define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
#define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
#define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
#define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
#define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
#define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) \
{ \
char* data = NULL; \
int len = 0; \
Symbol* name = (clss)->name(); \
if (name != NULL) { \
data = (char*)name->bytes(); \
len = name->utf8_length(); \
} \
HOTSPOT_CLASS_INITIALIZATION_##type( \
data, len, (void *)(clss)->class_loader(), thread_type); \
}
#define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
{ \
char* data = NULL; \
int len = 0; \
Symbol* name = (clss)->name(); \
if (name != NULL) { \
data = (char*)name->bytes(); \
len = name->utf8_length(); \
} \
HOTSPOT_CLASS_INITIALIZATION_##type( \
data, len, (void *)(clss)->class_loader(), thread_type, wait); \
}
#endif /* USDT2 */
#else // ndef DTRACE_ENABLED
#define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
#define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
#endif // ndef DTRACE_ENABLED
volatile int InstanceKlass::_total_instanceKlass_count = 0;
InstanceKlass* InstanceKlass::allocate_instance_klass(
ClassLoaderData* loader_data,
int vtable_len,
int itable_len,
int static_field_size,
int nonstatic_oop_map_size,
ReferenceType rt,
AccessFlags access_flags,
Symbol* name,
Klass* super_klass,
bool is_anonymous,
TRAPS) {
int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
access_flags.is_interface(), is_anonymous);
// Allocation
InstanceKlass* ik;
if (rt == REF_NONE) {
if (name == vmSymbols::java_lang_Class()) {
ik = new (loader_data, size, THREAD) InstanceMirrorKlass(
vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
access_flags, is_anonymous);
} else if (name == vmSymbols::java_lang_ClassLoader() ||
(SystemDictionary::ClassLoader_klass_loaded() &&
super_klass != NULL &&
super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass()))) {
ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(
vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
access_flags, is_anonymous);
} else {
// normal class
ik = new (loader_data, size, THREAD) InstanceKlass(
vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
access_flags, is_anonymous);
}
} else {
// reference klass
ik = new (loader_data, size, THREAD) InstanceRefKlass(
vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
access_flags, is_anonymous);
}
// Check for pending exception before adding to the loader data and incrementing
// class count. Can get OOM here.
if (HAS_PENDING_EXCEPTION) {
return NULL;
}
// Add all classes to our internal class loader list here,
// including classes in the bootstrap (NULL) class loader.
loader_data->add_class(ik);
Atomic::inc(&_total_instanceKlass_count);
return ik;
}
// copy method ordering from resource area to Metaspace
void InstanceKlass::copy_method_ordering(intArray* m, TRAPS) {
if (m != NULL) {
// allocate a new array and copy contents (memcpy?)
_method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
for (int i = 0; i < m->length(); i++) {
_method_ordering->at_put(i, m->at(i));
}
} else {
_method_ordering = Universe::the_empty_int_array();
}
}
// create a new array of vtable_indices for default methods
Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
assert(default_vtable_indices() == NULL, "only create once");
set_default_vtable_indices(vtable_indices);
return vtable_indices;
}
InstanceKlass::InstanceKlass(int vtable_len,
int itable_len,
int static_field_size,
int nonstatic_oop_map_size,
ReferenceType rt,
AccessFlags access_flags,
bool is_anonymous) {
No_Safepoint_Verifier no_safepoint; // until k becomes parsable
int iksize = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
access_flags.is_interface(), is_anonymous);
set_vtable_length(vtable_len);
set_itable_length(itable_len);
set_static_field_size(static_field_size);
set_nonstatic_oop_map_size(nonstatic_oop_map_size);
set_access_flags(access_flags);
_misc_flags = 0; // initialize to zero
set_is_anonymous(is_anonymous);
assert(size() == iksize, "wrong size for object");
set_array_klasses(NULL);
set_methods(NULL);
set_method_ordering(NULL);
set_default_methods(NULL);
set_default_vtable_indices(NULL);
set_local_interfaces(NULL);
set_transitive_interfaces(NULL);
init_implementor();
set_fields(NULL, 0);
set_constants(NULL);
set_class_loader_data(NULL);
set_source_file_name_index(0);
set_source_debug_extension(NULL, 0);
set_array_name(NULL);
set_inner_classes(NULL);
set_static_oop_field_count(0);
set_nonstatic_field_size(0);
set_is_marked_dependent(false);
set_has_unloaded_dependent(false);
set_init_state(InstanceKlass::allocated);
set_init_thread(NULL);
set_init_state(allocated);
set_reference_type(rt);
set_oop_map_cache(NULL);
set_jni_ids(NULL);
set_osr_nmethods_head(NULL);
set_breakpoints(NULL);
init_previous_versions();
set_generic_signature_index(0);
release_set_methods_jmethod_ids(NULL);
set_annotations(NULL);
set_jvmti_cached_class_field_map(NULL);
set_initial_method_idnum(0);
_dependencies = NULL;
set_jvmti_cached_class_field_map(NULL);
set_cached_class_file(NULL);
set_initial_method_idnum(0);
set_minor_version(0);
set_major_version(0);
NOT_PRODUCT(_verify_count = 0;)
// initialize the non-header words to zero
intptr_t* p = (intptr_t*)this;
for (int index = InstanceKlass::header_size(); index < iksize; index++) {
p[index] = NULL_WORD;
}
// Set temporary value until parseClassFile updates it with the real instance
// size.
set_layout_helper(Klass::instance_layout_helper(0, true));
}
void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
Array<Method*>* methods) {
if (methods != NULL && methods != Universe::the_empty_method_array() &&
!methods->is_shared()) {
for (int i = 0; i < methods->length(); i++) {
Method* method = methods->at(i);
if (method == NULL) continue; // maybe null if error processing
// Only want to delete methods that are not executing for RedefineClasses.
// The previous version will point to them so they're not totally dangling
assert (!method->on_stack(), "shouldn't be called with methods on stack");
MetadataFactory::free_metadata(loader_data, method);
}
MetadataFactory::free_array<Method*>(loader_data, methods);
}
}
void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
Klass* super_klass,
Array<Klass*>* local_interfaces,
Array<Klass*>* transitive_interfaces) {
// Only deallocate transitive interfaces if not empty, same as super class
// or same as local interfaces. See code in parseClassFile.
Array<Klass*>* ti = transitive_interfaces;
if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
// check that the interfaces don't come from super class
Array<Klass*>* sti = (super_klass == NULL) ? NULL :
InstanceKlass::cast(super_klass)->transitive_interfaces();
if (ti != sti && ti != NULL && !ti->is_shared()) {
MetadataFactory::free_array<Klass*>(loader_data, ti);
}
}
// local interfaces can be empty
if (local_interfaces != Universe::the_empty_klass_array() &&
local_interfaces != NULL && !local_interfaces->is_shared()) {
MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
}
}
// This function deallocates the metadata and C heap pointers that the
// InstanceKlass points to.
void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
// Orphan the mirror first, CMS thinks it's still live.
if (java_mirror() != NULL) {
java_lang_Class::set_klass(java_mirror(), NULL);
}
// Need to take this class off the class loader data list.
loader_data->remove_class(this);
// The array_klass for this class is created later, after error handling.
// For class redefinition, we keep the original class so this scratch class
// doesn't have an array class. Either way, assert that there is nothing
// to deallocate.
assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
// Release C heap allocated data that this might point to, which includes
// reference counting symbol names.
release_C_heap_structures();
deallocate_methods(loader_data, methods());
set_methods(NULL);
if (method_ordering() != NULL &&
method_ordering() != Universe::the_empty_int_array() &&
!method_ordering()->is_shared()) {
MetadataFactory::free_array<int>(loader_data, method_ordering());
}
set_method_ordering(NULL);
// default methods can be empty
if (default_methods() != NULL &&
default_methods() != Universe::the_empty_method_array() &&
!default_methods()->is_shared()) {
MetadataFactory::free_array<Method*>(loader_data, default_methods());
}
// Do NOT deallocate the default methods, they are owned by superinterfaces.
set_default_methods(NULL);
// default methods vtable indices can be empty
if (default_vtable_indices() != NULL &&
!default_vtable_indices()->is_shared()) {
MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
}
set_default_vtable_indices(NULL);
// This array is in Klass, but remove it with the InstanceKlass since
// this place would be the only caller and it can share memory with transitive
// interfaces.
if (secondary_supers() != NULL &&
secondary_supers() != Universe::the_empty_klass_array() &&
secondary_supers() != transitive_interfaces() &&
!secondary_supers()->is_shared()) {
MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
}
set_secondary_supers(NULL);
deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
set_transitive_interfaces(NULL);
set_local_interfaces(NULL);
if (fields() != NULL && !fields()->is_shared()) {
MetadataFactory::free_array<jushort>(loader_data, fields());
}
set_fields(NULL, 0);
// If a method from a redefined class is using this constant pool, don't
// delete it, yet. The new class's previous version will point to this.
if (constants() != NULL) {
assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
if (!constants()->is_shared()) {
MetadataFactory::free_metadata(loader_data, constants());
}
// Delete any cached resolution errors for the constant pool
SystemDictionary::delete_resolution_error(constants());
set_constants(NULL);
}
if (inner_classes() != NULL &&
inner_classes() != Universe::the_empty_short_array() &&
!inner_classes()->is_shared()) {
MetadataFactory::free_array<jushort>(loader_data, inner_classes());
}
set_inner_classes(NULL);
// We should deallocate the Annotations instance if it's not in shared spaces.
if (annotations() != NULL && !annotations()->is_shared()) {
MetadataFactory::free_metadata(loader_data, annotations());
}
set_annotations(NULL);
}
bool InstanceKlass::should_be_initialized() const {
return !is_initialized();
}
klassVtable* InstanceKlass::vtable() const {
return new klassVtable(this, start_of_vtable(), vtable_length() / vtableEntry::size());
}
klassItable* InstanceKlass::itable() const {
return new klassItable(instanceKlassHandle(this));
}
void InstanceKlass::eager_initialize(Thread *thread) {
if (!EagerInitialization) return;
if (this->is_not_initialized()) {
// abort if the the class has a class initializer
if (this->class_initializer() != NULL) return;
// abort if it is java.lang.Object (initialization is handled in genesis)
Klass* super = this->super();
if (super == NULL) return;
// abort if the super class should be initialized
if (!InstanceKlass::cast(super)->is_initialized()) return;
// call body to expose the this pointer
instanceKlassHandle this_oop(thread, this);
eager_initialize_impl(this_oop);
}
}
// JVMTI spec thinks there are signers and protection domain in the
// instanceKlass. These accessors pretend these fields are there.
// The hprof specification also thinks these fields are in InstanceKlass.
oop InstanceKlass::protection_domain() const {
// return the protection_domain from the mirror
return java_lang_Class::protection_domain(java_mirror());
}
// To remove these from requires an incompatible change and CCC request.
objArrayOop InstanceKlass::signers() const {
// return the signers from the mirror
return java_lang_Class::signers(java_mirror());
}
oop InstanceKlass::init_lock() const {
// return the init lock from the mirror
oop lock = java_lang_Class::init_lock(java_mirror());
// Prevent reordering with any access of initialization state
OrderAccess::loadload();
assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
"only fully initialized state can have a null lock");
return lock;
}
// Set the initialization lock to null so the object can be GC'ed. Any racing
// threads to get this lock will see a null lock and will not lock.
// That's okay because they all check for initialized state after getting
// the lock and return.
void InstanceKlass::fence_and_clear_init_lock() {
// make sure previous stores are all done, notably the init_state.
OrderAccess::storestore();
java_lang_Class::set_init_lock(java_mirror(), NULL);
assert(!is_not_initialized(), "class must be initialized now");
}
void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
EXCEPTION_MARK;
oop init_lock = this_oop->init_lock();
ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
// abort if someone beat us to the initialization
if (!this_oop->is_not_initialized()) return; // note: not equivalent to is_initialized()
ClassState old_state = this_oop->init_state();
link_class_impl(this_oop, true, THREAD);
if (HAS_PENDING_EXCEPTION) {
CLEAR_PENDING_EXCEPTION;
// Abort if linking the class throws an exception.
// Use a test to avoid redundantly resetting the state if there's
// no change. Set_init_state() asserts that state changes make
// progress, whereas here we might just be spinning in place.
if( old_state != this_oop->_init_state )
this_oop->set_init_state (old_state);
} else {
// linking successfull, mark class as initialized
this_oop->set_init_state (fully_initialized);
this_oop->fence_and_clear_init_lock();
// trace
if (TraceClassInitialization) {
ResourceMark rm(THREAD);
tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
}
}
}
// See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
// process. The step comments refers to the procedure described in that section.
// Note: implementation moved to static method to expose the this pointer.
void InstanceKlass::initialize(TRAPS) {
if (this->should_be_initialized()) {
HandleMark hm(THREAD);
instanceKlassHandle this_oop(THREAD, this);
initialize_impl(this_oop, CHECK);
// Note: at this point the class may be initialized
// OR it may be in the state of being initialized
// in case of recursive initialization!
} else {
assert(is_initialized(), "sanity check");
}
}
bool InstanceKlass::verify_code(
instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
// 1) Verify the bytecodes
Verifier::Mode mode =
throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), THREAD);
}
// Used exclusively by the shared spaces dump mechanism to prevent
// classes mapped into the shared regions in new VMs from appearing linked.
void InstanceKlass::unlink_class() {
assert(is_linked(), "must be linked");
_init_state = loaded;
}
void InstanceKlass::link_class(TRAPS) {
assert(is_loaded(), "must be loaded");
if (!is_linked()) {
HandleMark hm(THREAD);
instanceKlassHandle this_oop(THREAD, this);
link_class_impl(this_oop, true, CHECK);
}
}
// Called to verify that a class can link during initialization, without
// throwing a VerifyError.
bool InstanceKlass::link_class_or_fail(TRAPS) {
assert(is_loaded(), "must be loaded");
if (!is_linked()) {
HandleMark hm(THREAD);
instanceKlassHandle this_oop(THREAD, this);
link_class_impl(this_oop, false, CHECK_false);
}
return is_linked();
}
bool InstanceKlass::link_class_impl(
instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
// check for error state.
// This is checking for the wrong state. If the state is initialization_error,
// then this class *was* linked. The CDS code does a try_link_class and uses
// initialization_error to mark classes to not include in the archive during
// DumpSharedSpaces. This should be removed when the CDS bug is fixed.
if (this_oop->is_in_error_state()) {
ResourceMark rm(THREAD);
THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
this_oop->external_name(), false);
}
// return if already verified
if (this_oop->is_linked()) {
return true;
}
// Timing
// timer handles recursion
assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
JavaThread* jt = (JavaThread*)THREAD;
// link super class before linking this class
instanceKlassHandle super(THREAD, this_oop->super());
if (super.not_null()) {
if (super->is_interface()) { // check if super class is an interface
ResourceMark rm(THREAD);
Exceptions::fthrow(
THREAD_AND_LOCATION,
vmSymbols::java_lang_IncompatibleClassChangeError(),
"class %s has interface %s as super class",
this_oop->external_name(),
super->external_name()
);
return false;
}
link_class_impl(super, throw_verifyerror, CHECK_false);
}
// link all interfaces implemented by this class before linking this class
Array<Klass*>* interfaces = this_oop->local_interfaces();
int num_interfaces = interfaces->length();
for (int index = 0; index < num_interfaces; index++) {
HandleMark hm(THREAD);
instanceKlassHandle ih(THREAD, interfaces->at(index));
link_class_impl(ih, throw_verifyerror, CHECK_false);
}
// in case the class is linked in the process of linking its superclasses
if (this_oop->is_linked()) {
return true;
}
// trace only the link time for this klass that includes
// the verification time
PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
ClassLoader::perf_class_link_selftime(),
ClassLoader::perf_classes_linked(),
jt->get_thread_stat()->perf_recursion_counts_addr(),
jt->get_thread_stat()->perf_timers_addr(),
PerfClassTraceTime::CLASS_LINK);
// verification & rewriting
{
oop init_lock = this_oop->init_lock();
ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
// rewritten will have been set if loader constraint error found
// on an earlier link attempt
// don't verify or rewrite if already rewritten
if (!this_oop->is_linked()) {
if (!this_oop->is_rewritten()) {
{
// Timer includes any side effects of class verification (resolution,
// etc), but not recursive entry into verify_code().
PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
ClassLoader::perf_class_verify_selftime(),
ClassLoader::perf_classes_verified(),
jt->get_thread_stat()->perf_recursion_counts_addr(),
jt->get_thread_stat()->perf_timers_addr(),
PerfClassTraceTime::CLASS_VERIFY);
bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
if (!verify_ok) {
return false;
}
}
// Just in case a side-effect of verify linked this class already
// (which can sometimes happen since the verifier loads classes
// using custom class loaders, which are free to initialize things)
if (this_oop->is_linked()) {
return true;
}
// also sets rewritten
this_oop->rewrite_class(CHECK_false);
} else if (this_oop()->is_shared()) {
ResourceMark rm(THREAD);
char* message_buffer; // res-allocated by check_verification_dependencies
Handle loader = this_oop()->class_loader();
Handle pd = this_oop()->protection_domain();
bool verified = SystemDictionaryShared::check_verification_dependencies(this_oop(),
loader, pd, &message_buffer, THREAD);
if (!verified) {
THROW_MSG_(vmSymbols::java_lang_VerifyError(), message_buffer, false);
}
}
// relocate jsrs and link methods after they are all rewritten
this_oop->link_methods(CHECK_false);
// Initialize the vtable and interface table after
// methods have been rewritten since rewrite may
// fabricate new Method*s.
// also does loader constraint checking
//
// Initialize_vtable and initialize_itable need to be rerun for
// a shared class if the class is not loaded by the NULL classloader.
ClassLoaderData * loader_data = this_oop->class_loader_data();
if (!(this_oop()->is_shared() &&
loader_data->is_the_null_class_loader_data())) {
ResourceMark rm(THREAD);
this_oop->vtable()->initialize_vtable(true, CHECK_false);
this_oop->itable()->initialize_itable(true, CHECK_false);
}
#ifdef ASSERT
else {
ResourceMark rm(THREAD);
this_oop->vtable()->verify(tty, true);
// In case itable verification is ever added.
// this_oop->itable()->verify(tty, true);
}
#endif
this_oop->set_init_state(linked);
if (JvmtiExport::should_post_class_prepare()) {
Thread *thread = THREAD;
assert(thread->is_Java_thread(), "thread->is_Java_thread()");
JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
}
}
}
return true;
}
// Rewrite the byte codes of all of the methods of a class.
// The rewriter must be called exactly once. Rewriting must happen after
// verification but before the first method of the class is executed.
void InstanceKlass::rewrite_class(TRAPS) {
assert(is_loaded(), "must be loaded");
instanceKlassHandle this_oop(THREAD, this);
if (this_oop->is_rewritten()) {
assert(this_oop()->is_shared(), "rewriting an unshared class?");
return;
}
Rewriter::rewrite(this_oop, CHECK);
this_oop->set_rewritten();
}
// Now relocate and link method entry points after class is rewritten.
// This is outside is_rewritten flag. In case of an exception, it can be
// executed more than once.
void InstanceKlass::link_methods(TRAPS) {
int len = methods()->length();
for (int i = len-1; i >= 0; i--) {
methodHandle m(THREAD, methods()->at(i));
// Set up method entry points for compiler and interpreter .
m->link_method(m, CHECK);
// This is for JVMTI and unrelated to relocator but the last thing we do
#ifdef ASSERT
if (StressMethodComparator) {
ResourceMark rm(THREAD);
static int nmc = 0;
for (int j = i; j >= 0 && j >= i-4; j--) {
if ((++nmc % 1000) == 0) tty->print_cr("Have run MethodComparator %d times...", nmc);
bool z = MethodComparator::methods_EMCP(m(),
methods()->at(j));
if (j == i && !z) {
tty->print("MethodComparator FAIL: "); m->print(); m->print_codes();
assert(z, "method must compare equal to itself");
}
}
}
#endif //ASSERT
}
}
// Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
void InstanceKlass::initialize_super_interfaces(instanceKlassHandle this_k, TRAPS) {
assert (this_k->has_default_methods(), "caller should have checked this");
for (int i = 0; i < this_k->local_interfaces()->length(); ++i) {
Klass* iface = this_k->local_interfaces()->at(i);
InstanceKlass* ik = InstanceKlass::cast(iface);
// Initialization is depth first search ie. we start with top of the inheritance tree
// has_default_methods drives searching superinterfaces since it
// means has_default_methods in its superinterface hierarchy
if (ik->has_default_methods()) {
ik->initialize_super_interfaces(ik, CHECK);
}
// Only initialize() interfaces that "declare" concrete methods.
if (ik->should_be_initialized() && ik->declares_default_methods()) {
ik->initialize(CHECK);
}
}
}
void InstanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
// Make sure klass is linked (verified) before initialization
// A class could already be verified, since it has been reflected upon.
this_oop->link_class(CHECK);
DTRACE_CLASSINIT_PROBE(required, InstanceKlass::cast(this_oop()), -1);
bool wait = false;
// refer to the JVM book page 47 for description of steps
// Step 1
{
oop init_lock = this_oop->init_lock();
ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
Thread *self = THREAD; // it's passed the current thread
// Step 2
// If we were to use wait() instead of waitInterruptibly() then
// we might end up throwing IE from link/symbol resolution sites
// that aren't expected to throw. This would wreak havoc. See 6320309.
while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
wait = true;
ol.waitUninterruptibly(CHECK);
}
// Step 3
if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
DTRACE_CLASSINIT_PROBE_WAIT(recursive, InstanceKlass::cast(this_oop()), -1,wait);
return;
}
// Step 4
if (this_oop->is_initialized()) {
DTRACE_CLASSINIT_PROBE_WAIT(concurrent, InstanceKlass::cast(this_oop()), -1,wait);
return;
}
// Step 5
if (this_oop->is_in_error_state()) {
DTRACE_CLASSINIT_PROBE_WAIT(erroneous, InstanceKlass::cast(this_oop()), -1,wait);
ResourceMark rm(THREAD);
const char* desc = "Could not initialize class ";
const char* className = this_oop->external_name();
size_t msglen = strlen(desc) + strlen(className) + 1;
char* message = NEW_RESOURCE_ARRAY(char, msglen);
if (NULL == message) {
// Out of memory: can't create detailed error message
THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
} else {
jio_snprintf(message, msglen, "%s%s", desc, className);
THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
}
}
// Step 6
this_oop->set_init_state(being_initialized);
this_oop->set_init_thread(self);
}
// Step 7
// Next, if C is a class rather than an interface, initialize its super class and super
// interfaces.
if (!this_oop->is_interface()) {
Klass* super_klass = this_oop->super();
if (super_klass != NULL && super_klass->should_be_initialized()) {
super_klass->initialize(THREAD);
}
// If C implements any interfaces that declares a non-abstract, non-static method,
// the initialization of C triggers initialization of its super interfaces.
// Only need to recurse if has_default_methods which includes declaring and
// inheriting default methods
if (!HAS_PENDING_EXCEPTION && this_oop->has_default_methods()) {
this_oop->initialize_super_interfaces(this_oop, THREAD);
}
// If any exceptions, complete abruptly, throwing the same exception as above.
if (HAS_PENDING_EXCEPTION) {
Handle e(THREAD, PENDING_EXCEPTION);
CLEAR_PENDING_EXCEPTION;
{
EXCEPTION_MARK;
// Locks object, set state, and notify all waiting threads
this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
CLEAR_PENDING_EXCEPTION;
}
DTRACE_CLASSINIT_PROBE_WAIT(super__failed, InstanceKlass::cast(this_oop()), -1,wait);
THROW_OOP(e());
}
}
// Step 8
{
assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
JavaThread* jt = (JavaThread*)THREAD;
DTRACE_CLASSINIT_PROBE_WAIT(clinit, InstanceKlass::cast(this_oop()), -1,wait);
// Timer includes any side effects of class initialization (resolution,
// etc), but not recursive entry into call_class_initializer().
PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
ClassLoader::perf_class_init_selftime(),
ClassLoader::perf_classes_inited(),
jt->get_thread_stat()->perf_recursion_counts_addr(),
jt->get_thread_stat()->perf_timers_addr(),
PerfClassTraceTime::CLASS_CLINIT);
this_oop->call_class_initializer(THREAD);
}
// Step 9
if (!HAS_PENDING_EXCEPTION) {
this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
{ ResourceMark rm(THREAD);
debug_only(this_oop->vtable()->verify(tty, true);)
}
}
else {
// Step 10 and 11
Handle e(THREAD, PENDING_EXCEPTION);
CLEAR_PENDING_EXCEPTION;
// JVMTI has already reported the pending exception
// JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
{
EXCEPTION_MARK;
this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
// JVMTI has already reported the pending exception
// JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
}
DTRACE_CLASSINIT_PROBE_WAIT(error, InstanceKlass::cast(this_oop()), -1,wait);
if (e->is_a(SystemDictionary::Error_klass())) {
THROW_OOP(e());
} else {
JavaCallArguments args(e);
THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
vmSymbols::throwable_void_signature(),
&args);
}
}
DTRACE_CLASSINIT_PROBE_WAIT(end, InstanceKlass::cast(this_oop()), -1,wait);
}
// Note: implementation moved to static method to expose the this pointer.
void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
instanceKlassHandle kh(THREAD, this);
set_initialization_state_and_notify_impl(kh, state, CHECK);
}
void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
oop init_lock = this_oop->init_lock();
if (init_lock != NULL) {
ObjectLocker ol(init_lock, THREAD);
this_oop->set_init_thread(NULL); // reset _init_thread before changing _init_state
this_oop->set_init_state(state);
this_oop->fence_and_clear_init_lock();
ol.notify_all(CHECK);
} else {
assert(init_lock != NULL, "The initialization state should never be set twice");
this_oop->set_init_thread(NULL); // reset _init_thread before changing _init_state
this_oop->set_init_state(state);
}
}
// The embedded _implementor field can only record one implementor.
// When there are more than one implementors, the _implementor field
// is set to the interface Klass* itself. Following are the possible
// values for the _implementor field:
// NULL - no implementor
// implementor Klass* - one implementor
// self - more than one implementor
//
// The _implementor field only exists for interfaces.
void InstanceKlass::add_implementor(Klass* k) {
assert(Compile_lock->owned_by_self(), "");
assert(is_interface(), "not interface");
// Filter out my subinterfaces.
// (Note: Interfaces are never on the subklass list.)
if (InstanceKlass::cast(k)->is_interface()) return;
// Filter out subclasses whose supers already implement me.
// (Note: CHA must walk subclasses of direct implementors
// in order to locate indirect implementors.)
Klass* sk = InstanceKlass::cast(k)->super();
if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
// We only need to check one immediate superclass, since the
// implements_interface query looks at transitive_interfaces.
// Any supers of the super have the same (or fewer) transitive_interfaces.
return;
Klass* ik = implementor();
if (ik == NULL) {
set_implementor(k);
} else if (ik != this) {
// There is already an implementor. Use itself as an indicator of
// more than one implementors.
set_implementor(this);
}
// The implementor also implements the transitive_interfaces
for (int index = 0; index < local_interfaces()->length(); index++) {
InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
}
}
void InstanceKlass::init_implementor() {
if (is_interface()) {
set_implementor(NULL);
}
}
void InstanceKlass::process_interfaces(Thread *thread) {
// link this class into the implementors list of every interface it implements
Klass* this_as_klass_oop = this;
for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
assert(interf->is_interface(), "expected interface");
interf->add_implementor(this_as_klass_oop);
}
}
bool InstanceKlass::can_be_primary_super_slow() const {
if (is_interface())
return false;
else
return Klass::can_be_primary_super_slow();
}
GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
// The secondaries are the implemented interfaces.
InstanceKlass* ik = InstanceKlass::cast(this);
Array<Klass*>* interfaces = ik->transitive_interfaces();
int num_secondaries = num_extra_slots + interfaces->length();
if (num_secondaries == 0) {
// Must share this for correct bootstrapping!
set_secondary_supers(Universe::the_empty_klass_array());
return NULL;
} else if (num_extra_slots == 0) {
// The secondary super list is exactly the same as the transitive interfaces.
// Redefine classes has to be careful not to delete this!
set_secondary_supers(interfaces);
return NULL;
} else {
// Copy transitive interfaces to a temporary growable array to be constructed
// into the secondary super list with extra slots.
GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
for (int i = 0; i < interfaces->length(); i++) {
secondaries->push(interfaces->at(i));
}
return secondaries;
}
}
bool InstanceKlass::compute_is_subtype_of(Klass* k) {
if (k->is_interface()) {
return implements_interface(k);
} else {
return Klass::compute_is_subtype_of(k);
}
}
bool InstanceKlass::implements_interface(Klass* k) const {
if (this == k) return true;
assert(k->is_interface(), "should be an interface class");
for (int i = 0; i < transitive_interfaces()->length(); i++) {
if (transitive_interfaces()->at(i) == k) {
return true;
}
}
return false;
}
bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
// Verify direct super interface
if (this == k) return true;
assert(k->is_interface(), "should be an interface class");
for (int i = 0; i < local_interfaces()->length(); i++) {
if (local_interfaces()->at(i) == k) {
return true;
}
}
return false;
}
objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
report_java_out_of_memory("Requested array size exceeds VM limit");
JvmtiExport::post_array_size_exhausted();
THROW_OOP_0(Universe::out_of_memory_error_array_size());
}
int size = objArrayOopDesc::object_size(length);
Klass* ak = array_klass(n, CHECK_NULL);
KlassHandle h_ak (THREAD, ak);
objArrayOop o =
(objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
return o;
}
instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
if (TraceFinalizerRegistration) {
tty->print("Registered ");
i->print_value_on(tty);
tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
}
instanceHandle h_i(THREAD, i);
// Pass the handle as argument, JavaCalls::call expects oop as jobjects
JavaValue result(T_VOID);
JavaCallArguments args(h_i);
methodHandle mh (THREAD, Universe::finalizer_register_method());
JavaCalls::call(&result, mh, &args, CHECK_NULL);
return h_i();
}
instanceOop InstanceKlass::allocate_instance(TRAPS) {
bool has_finalizer_flag = has_finalizer(); // Query before possible GC
int size = size_helper(); // Query before forming handle.
KlassHandle h_k(THREAD, this);
instanceOop i;
i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
if (has_finalizer_flag && !RegisterFinalizersAtInit) {
i = register_finalizer(i, CHECK_NULL);
}
return i;
}
void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
if (is_interface() || is_abstract()) {
ResourceMark rm(THREAD);
THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
: vmSymbols::java_lang_InstantiationException(), external_name());
}
if (this == SystemDictionary::Class_klass()) {
ResourceMark rm(THREAD);
THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
: vmSymbols::java_lang_IllegalAccessException(), external_name());
}
}
Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
instanceKlassHandle this_oop(THREAD, this);
return array_klass_impl(this_oop, or_null, n, THREAD);
}
Klass* InstanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
if (this_oop->array_klasses() == NULL) {
if (or_null) return NULL;
ResourceMark rm;
JavaThread *jt = (JavaThread *)THREAD;
{
// Atomic creation of array_klasses
MutexLocker mc(Compile_lock, THREAD); // for vtables
MutexLocker ma(MultiArray_lock, THREAD);
// Check if update has already taken place
if (this_oop->array_klasses() == NULL) {
Klass* k = ObjArrayKlass::allocate_objArray_klass(this_oop->class_loader_data(), 1, this_oop, CHECK_NULL);
this_oop->set_array_klasses(k);
}
}
}
// _this will always be set at this point
ObjArrayKlass* oak = (ObjArrayKlass*)this_oop->array_klasses();
if (or_null) {
return oak->array_klass_or_null(n);
}
return oak->array_klass(n, THREAD);
}
Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
return array_klass_impl(or_null, 1, THREAD);
}
void InstanceKlass::call_class_initializer(TRAPS) {
instanceKlassHandle ik (THREAD, this);
call_class_initializer_impl(ik, THREAD);
}
static int call_class_initializer_impl_counter = 0; // for debugging
Method* InstanceKlass::class_initializer() {
Method* clinit = find_method(
vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
if (clinit != NULL && clinit->has_valid_initializer_flags()) {
return clinit;
}
return NULL;
}
void InstanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
if (ReplayCompiles &&
(ReplaySuppressInitializers == 1 ||
ReplaySuppressInitializers >= 2 && this_oop->class_loader() != NULL)) {
// Hide the existence of the initializer for the purpose of replaying the compile
return;
}
methodHandle h_method(THREAD, this_oop->class_initializer());
assert(!this_oop->is_initialized(), "we cannot initialize twice");
if (TraceClassInitialization) {
tty->print("%d Initializing ", call_class_initializer_impl_counter++);
this_oop->name()->print_value();
tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
}
if (h_method() != NULL) {
JavaCallArguments args; // No arguments
JavaValue result(T_VOID);
JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
}
}
void InstanceKlass::mask_for(methodHandle method, int bci,
InterpreterOopMap* entry_for) {
// Dirty read, then double-check under a lock.
if (_oop_map_cache == NULL) {
// Otherwise, allocate a new one.
MutexLocker x(OopMapCacheAlloc_lock);
// First time use. Allocate a cache in C heap
if (_oop_map_cache == NULL) {
// Release stores from OopMapCache constructor before assignment
// to _oop_map_cache. C++ compilers on ppc do not emit the
// required memory barrier only because of the volatile
// qualifier of _oop_map_cache.
OrderAccess::release_store_ptr(&_oop_map_cache, new OopMapCache());
}
}
// _oop_map_cache is constant after init; lookup below does is own locking.
_oop_map_cache->lookup(method, bci, entry_for);
}
bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
Symbol* f_name = fs.name();
Symbol* f_sig = fs.signature();
if (f_name == name && f_sig == sig) {
fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
return true;
}
}
return false;
}
Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
const int n = local_interfaces()->length();
for (int i = 0; i < n; i++) {
Klass* intf1 = local_interfaces()->at(i);
assert(intf1->is_interface(), "just checking type");
// search for field in current interface
if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
assert(fd->is_static(), "interface field must be static");
return intf1;
}
// search for field in direct superinterfaces
Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
if (intf2 != NULL) return intf2;
}
// otherwise field lookup fails
return NULL;
}
Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
// search order according to newest JVM spec (5.4.3.2, p.167).
// 1) search for field in current klass
if (find_local_field(name, sig, fd)) {
return const_cast<InstanceKlass*>(this);
}
// 2) search for field recursively in direct superinterfaces
{ Klass* intf = find_interface_field(name, sig, fd);
if (intf != NULL) return intf;
}
// 3) apply field lookup recursively if superclass exists
{ Klass* supr = super();
if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
}
// 4) otherwise field lookup fails
return NULL;
}
Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
// search order according to newest JVM spec (5.4.3.2, p.167).
// 1) search for field in current klass
if (find_local_field(name, sig, fd)) {
if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
}
// 2) search for field recursively in direct superinterfaces
if (is_static) {
Klass* intf = find_interface_field(name, sig, fd);
if (intf != NULL) return intf;
}
// 3) apply field lookup recursively if superclass exists
{ Klass* supr = super();
if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
}
// 4) otherwise field lookup fails
return NULL;
}
bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
if (fs.offset() == offset) {
fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
if (fd->is_static() == is_static) return true;
}
}
return false;
}
bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
Klass* klass = const_cast<InstanceKlass*>(this);
while (klass != NULL) {
if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
return true;
}
klass = klass->super();
}
return false;
}
void InstanceKlass::methods_do(void f(Method* method)) {
int len = methods()->length();
for (int index = 0; index < len; index++) {
Method* m = methods()->at(index);
assert(m->is_method(), "must be method");
f(m);
}
}
void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
if (fs.access_flags().is_static()) {
fieldDescriptor& fd = fs.field_descriptor();
cl->do_field(&fd);
}
}
}
void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
instanceKlassHandle h_this(THREAD, this);
do_local_static_fields_impl(h_this, f, mirror, CHECK);
}
void InstanceKlass::do_local_static_fields_impl(instanceKlassHandle this_k,
void f(fieldDescriptor* fd, Handle mirror, TRAPS), Handle mirror, TRAPS) {
for (JavaFieldStream fs(this_k()); !fs.done(); fs.next()) {
if (fs.access_flags().is_static()) {
fieldDescriptor& fd = fs.field_descriptor();
f(&fd, mirror, CHECK);
}
}
}
static int compare_fields_by_offset(int* a, int* b) {
return a[0] - b[0];
}
void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
InstanceKlass* super = superklass();
if (super != NULL) {
super->do_nonstatic_fields(cl);
}
fieldDescriptor fd;
int length = java_fields_count();
// In DebugInfo nonstatic fields are sorted by offset.
int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
int j = 0;
for (int i = 0; i < length; i += 1) {
fd.reinitialize(this, i);
if (!fd.is_static()) {
fields_sorted[j + 0] = fd.offset();
fields_sorted[j + 1] = i;
j += 2;
}
}
if (j > 0) {
length = j;
// _sort_Fn is defined in growableArray.hpp.
qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
for (int i = 0; i < length; i += 2) {
fd.reinitialize(this, fields_sorted[i + 1]);
assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
cl->do_field(&fd);
}
}
FREE_C_HEAP_ARRAY(int, fields_sorted, mtClass);
}
void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
if (array_klasses() != NULL)
ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
}
void InstanceKlass::array_klasses_do(void f(Klass* k)) {
if (array_klasses() != NULL)
ArrayKlass::cast(array_klasses())->array_klasses_do(f);
}
#ifdef ASSERT
static int linear_search(Array<Method*>* methods, Symbol* name, Symbol* signature) {
int len = methods->length();
for (int index = 0; index < len; index++) {
Method* m = methods->at(index);
assert(m->is_method(), "must be method");
if (m->signature() == signature && m->name() == name) {
return index;
}
}
return -1;
}
#endif
static int binary_search(Array<Method*>* methods, Symbol* name) {
int len = methods->length();
// methods are sorted, so do binary search
int l = 0;
int h = len - 1;
while (l <= h) {
int mid = (l + h) >> 1;
Method* m = methods->at(mid);
assert(m->is_method(), "must be method");
int res = m->name()->fast_compare(name);
if (res == 0) {
return mid;
} else if (res < 0) {
l = mid + 1;
} else {
h = mid - 1;
}
}
return -1;
}
// find_method looks up the name/signature in the local methods array
Method* InstanceKlass::find_method(Symbol* name, Symbol* signature) const {
return find_method_impl(name, signature, find_overpass, find_static, find_private);
}
Method* InstanceKlass::find_method_impl(Symbol* name, Symbol* signature,
OverpassLookupMode overpass_mode,
StaticLookupMode static_mode,
PrivateLookupMode private_mode) const {
return InstanceKlass::find_method_impl(methods(), name, signature, overpass_mode, static_mode, private_mode);
}
// find_instance_method looks up the name/signature in the local methods array
// and skips over static methods
Method* InstanceKlass::find_instance_method(
Array<Method*>* methods, Symbol* name, Symbol* signature) {
Method* meth = InstanceKlass::find_method_impl(methods, name, signature,
find_overpass, skip_static, find_private);
assert(((meth == NULL) || !meth->is_static()), "find_instance_method should have skipped statics");
return meth;
}
// find_instance_method looks up the name/signature in the local methods array
// and skips over static methods
Method* InstanceKlass::find_instance_method(Symbol* name, Symbol* signature) {
return InstanceKlass::find_instance_method(methods(), name, signature);
}
// Find looks up the name/signature in the local methods array
// and filters on the overpass, static and private flags
// This returns the first one found
// note that the local methods array can have up to one overpass, one static
// and one instance (private or not) with the same name/signature
Method* InstanceKlass::find_local_method(Symbol* name, Symbol* signature,
OverpassLookupMode overpass_mode,
StaticLookupMode static_mode,
PrivateLookupMode private_mode) const {
return InstanceKlass::find_method_impl(methods(), name, signature, overpass_mode, static_mode, private_mode);
}
// Find looks up the name/signature in the local methods array
// and filters on the overpass, static and private flags
// This returns the first one found
// note that the local methods array can have up to one overpass, one static
// and one instance (private or not) with the same name/signature
Method* InstanceKlass::find_local_method(Array<Method*>* methods,
Symbol* name, Symbol* signature,
OverpassLookupMode overpass_mode,
StaticLookupMode static_mode,
PrivateLookupMode private_mode) {
return InstanceKlass::find_method_impl(methods, name, signature, overpass_mode, static_mode, private_mode);
}
// find_method looks up the name/signature in the local methods array
Method* InstanceKlass::find_method(
Array<Method*>* methods, Symbol* name, Symbol* signature) {
return InstanceKlass::find_method_impl(methods, name, signature, find_overpass, find_static, find_private);
}
Method* InstanceKlass::find_method_impl(
Array<Method*>* methods, Symbol* name, Symbol* signature,
OverpassLookupMode overpass_mode, StaticLookupMode static_mode,
PrivateLookupMode private_mode) {
int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
return hit >= 0 ? methods->at(hit): NULL;
}
bool InstanceKlass::method_matches(Method* m, Symbol* signature, bool skipping_overpass, bool skipping_static, bool skipping_private) {
return ((m->signature() == signature) &&
(!skipping_overpass || !m->is_overpass()) &&
(!skipping_static || !m->is_static()) &&
(!skipping_private || !m->is_private()));
}
// Used directly for default_methods to find the index into the
// default_vtable_indices, and indirectly by find_method
// find_method_index looks in the local methods array to return the index
// of the matching name/signature. If, overpass methods are being ignored,
// the search continues to find a potential non-overpass match. This capability
// is important during method resolution to prefer a static method, for example,
// over an overpass method.
// There is the possibility in any _method's array to have the same name/signature
// for a static method, an overpass method and a local instance method
// To correctly catch a given method, the search criteria may need
// to explicitly skip the other two. For local instance methods, it
// is often necessary to skip private methods
int InstanceKlass::find_method_index(
Array<Method*>* methods, Symbol* name, Symbol* signature,
OverpassLookupMode overpass_mode, StaticLookupMode static_mode,
PrivateLookupMode private_mode) {
bool skipping_overpass = (overpass_mode == skip_overpass);
bool skipping_static = (static_mode == skip_static);
bool skipping_private = (private_mode == skip_private);
int hit = binary_search(methods, name);
if (hit != -1) {
Method* m = methods->at(hit);
// Do linear search to find matching signature. First, quick check
// for common case, ignoring overpasses if requested.
if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) return hit;
// search downwards through overloaded methods
int i;
for (i = hit - 1; i >= 0; --i) {
Method* m = methods->at(i);
assert(m->is_method(), "must be method");
if (m->name() != name) break;
if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) return i;
}
// search upwards
for (i = hit + 1; i < methods->length(); ++i) {
Method* m = methods->at(i);
assert(m->is_method(), "must be method");
if (m->name() != name) break;
if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) return i;
}
// not found
#ifdef ASSERT
int index = (skipping_overpass || skipping_static || skipping_private) ? -1 : linear_search(methods, name, signature);
assert(index == -1, err_msg("binary search should have found entry %d", index));
#endif
}
return -1;
}
int InstanceKlass::find_method_by_name(Symbol* name, int* end) {
return find_method_by_name(methods(), name, end);
}
int InstanceKlass::find_method_by_name(
Array<Method*>* methods, Symbol* name, int* end_ptr) {
assert(end_ptr != NULL, "just checking");
int start = binary_search(methods, name);
int end = start + 1;
if (start != -1) {
while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
while (end < methods->length() && (methods->at(end))->name() == name) ++end;
*end_ptr = end;
return start;
}
return -1;
}
// uncached_lookup_method searches both the local class methods array and all
// superclasses methods arrays, skipping any overpass methods in superclasses.
Method* InstanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature, OverpassLookupMode overpass_mode) const {
OverpassLookupMode overpass_local_mode = overpass_mode;
Klass* klass = const_cast<InstanceKlass*>(this);
while (klass != NULL) {
Method* method = InstanceKlass::cast(klass)->find_method_impl(name, signature, overpass_local_mode, find_static, find_private);
if (method != NULL) {
return method;
}
klass = InstanceKlass::cast(klass)->super();
overpass_local_mode = skip_overpass; // Always ignore overpass methods in superclasses
}
return NULL;
}
#ifdef ASSERT
// search through class hierarchy and return true if this class or
// one of the superclasses was redefined
bool InstanceKlass::has_redefined_this_or_super() const {
const InstanceKlass* klass = this;
while (klass != NULL) {
if (klass->has_been_redefined()) {
return true;
}
klass = InstanceKlass::cast(klass->super());
}
return false;
}
#endif
// lookup a method in the default methods list then in all transitive interfaces
// Do NOT return private or static methods
Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
Symbol* signature) const {
Method* m = NULL;
if (default_methods() != NULL) {
m = find_method(default_methods(), name, signature);
}
// Look up interfaces
if (m == NULL) {
m = lookup_method_in_all_interfaces(name, signature, find_defaults);
}
return m;
}
// lookup a method in all the interfaces that this class implements
// Do NOT return private or static methods, new in JDK8 which are not externally visible
// They should only be found in the initial InterfaceMethodRef
Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
Symbol* signature,
DefaultsLookupMode defaults_mode) const {
Array<Klass*>* all_ifs = transitive_interfaces();
int num_ifs = all_ifs->length();
InstanceKlass *ik = NULL;
for (int i = 0; i < num_ifs; i++) {
ik = InstanceKlass::cast(all_ifs->at(i));
Method* m = ik->lookup_method(name, signature);
if (m != NULL && m->is_public() && !m->is_static() &&
((defaults_mode != skip_defaults) || !m->is_default_method())) {
return m;
}
}
return NULL;
}
/* jni_id_for_impl for jfieldIds only */
JNIid* InstanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
MutexLocker ml(JfieldIdCreation_lock);
// Retry lookup after we got the lock
JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
if (probe == NULL) {
// Slow case, allocate new static field identifier
probe = new JNIid(this_oop(), offset, this_oop->jni_ids());
this_oop->set_jni_ids(probe);
}
return probe;
}
/* jni_id_for for jfieldIds only */
JNIid* InstanceKlass::jni_id_for(int offset) {
JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
if (probe == NULL) {
probe = jni_id_for_impl(this, offset);
}
return probe;
}
u2 InstanceKlass::enclosing_method_data(int offset) {
Array<jushort>* inner_class_list = inner_classes();
if (inner_class_list == NULL) {
return 0;
}
int length = inner_class_list->length();
if (length % inner_class_next_offset == 0) {
return 0;
} else {
int index = length - enclosing_method_attribute_size;
assert(offset < enclosing_method_attribute_size, "invalid offset");
return inner_class_list->at(index + offset);
}
}
void InstanceKlass::set_enclosing_method_indices(u2 class_index,
u2 method_index) {
Array<jushort>* inner_class_list = inner_classes();
assert (inner_class_list != NULL, "_inner_classes list is not set up");
int length = inner_class_list->length();
if (length % inner_class_next_offset == enclosing_method_attribute_size) {
int index = length - enclosing_method_attribute_size;
inner_class_list->at_put(
index + enclosing_method_class_index_offset, class_index);
inner_class_list->at_put(
index + enclosing_method_method_index_offset, method_index);
}
}
// Lookup or create a jmethodID.
// This code is called by the VMThread and JavaThreads so the
// locking has to be done very carefully to avoid deadlocks
// and/or other cache consistency problems.
//
jmethodID InstanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
size_t idnum = (size_t)method_h->method_idnum();
jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
size_t length = 0;
jmethodID id = NULL;
// We use a double-check locking idiom here because this cache is
// performance sensitive. In the normal system, this cache only
// transitions from NULL to non-NULL which is safe because we use
// release_set_methods_jmethod_ids() to advertise the new cache.
// A partially constructed cache should never be seen by a racing
// thread. We also use release_store_ptr() to save a new jmethodID
// in the cache so a partially constructed jmethodID should never be
// seen either. Cache reads of existing jmethodIDs proceed without a
// lock, but cache writes of a new jmethodID requires uniqueness and
// creation of the cache itself requires no leaks so a lock is
// generally acquired in those two cases.
//
// If the RedefineClasses() API has been used, then this cache can
// grow and we'll have transitions from non-NULL to bigger non-NULL.
// Cache creation requires no leaks and we require safety between all
// cache accesses and freeing of the old cache so a lock is generally
// acquired when the RedefineClasses() API has been used.
if (jmeths != NULL) {
// the cache already exists
if (!ik_h->idnum_can_increment()) {
// the cache can't grow so we can just get the current values
get_jmethod_id_length_value(jmeths, idnum, &length, &id);
} else {
// cache can grow so we have to be more careful
if (Threads::number_of_threads() == 0 ||
SafepointSynchronize::is_at_safepoint()) {
// we're single threaded or at a safepoint - no locking needed
get_jmethod_id_length_value(jmeths, idnum, &length, &id);
} else {
MutexLocker ml(JmethodIdCreation_lock);
get_jmethod_id_length_value(jmeths, idnum, &length, &id);
}
}
}
// implied else:
// we need to allocate a cache so default length and id values are good
if (jmeths == NULL || // no cache yet
length <= idnum || // cache is too short
id == NULL) { // cache doesn't contain entry
// This function can be called by the VMThread so we have to do all
// things that might block on a safepoint before grabbing the lock.
// Otherwise, we can deadlock with the VMThread or have a cache
// consistency issue. These vars keep track of what we might have
// to free after the lock is dropped.
jmethodID to_dealloc_id = NULL;
jmethodID* to_dealloc_jmeths = NULL;
// may not allocate new_jmeths or use it if we allocate it
jmethodID* new_jmeths = NULL;
if (length <= idnum) {
// allocate a new cache that might be used
size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
// cache size is stored in element[0], other elements offset by one
new_jmeths[0] = (jmethodID)size;
}
// allocate a new jmethodID that might be used
jmethodID new_id = NULL;
if (method_h->is_old() && !method_h->is_obsolete()) {
// The method passed in is old (but not obsolete), we need to use the current version
Method* current_method = ik_h->method_with_idnum((int)idnum);
assert(current_method != NULL, "old and but not obsolete, so should exist");
new_id = Method::make_jmethod_id(ik_h->class_loader_data(), current_method);
} else {
// It is the current version of the method or an obsolete method,
// use the version passed in
new_id = Method::make_jmethod_id(ik_h->class_loader_data(), method_h());
}
if (Threads::number_of_threads() == 0 ||
SafepointSynchronize::is_at_safepoint()) {
// we're single threaded or at a safepoint - no locking needed
id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
&to_dealloc_id, &to_dealloc_jmeths);
} else {
MutexLocker ml(JmethodIdCreation_lock);
id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
&to_dealloc_id, &to_dealloc_jmeths);
}
// The lock has been dropped so we can free resources.
// Free up either the old cache or the new cache if we allocated one.
if (to_dealloc_jmeths != NULL) {
FreeHeap(to_dealloc_jmeths);
}
// free up the new ID since it wasn't needed
if (to_dealloc_id != NULL) {
Method::destroy_jmethod_id(ik_h->class_loader_data(), to_dealloc_id);
}
}
return id;
}
// Common code to fetch the jmethodID from the cache or update the
// cache with the new jmethodID. This function should never do anything
// that causes the caller to go to a safepoint or we can deadlock with
// the VMThread or have cache consistency issues.
//
jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
jmethodID** to_dealloc_jmeths_p) {
assert(new_id != NULL, "sanity check");
assert(to_dealloc_id_p != NULL, "sanity check");
assert(to_dealloc_jmeths_p != NULL, "sanity check");
assert(Threads::number_of_threads() == 0 ||
SafepointSynchronize::is_at_safepoint() ||
JmethodIdCreation_lock->owned_by_self(), "sanity check");
// reacquire the cache - we are locked, single threaded or at a safepoint
jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
jmethodID id = NULL;
size_t length = 0;
if (jmeths == NULL || // no cache yet
(length = (size_t)jmeths[0]) <= idnum) { // cache is too short
if (jmeths != NULL) {
// copy any existing entries from the old cache
for (size_t index = 0; index < length; index++) {
new_jmeths[index+1] = jmeths[index+1];
}
*to_dealloc_jmeths_p = jmeths; // save old cache for later delete
}
ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
} else {
// fetch jmethodID (if any) from the existing cache
id = jmeths[idnum+1];
*to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
}
if (id == NULL) {
// No matching jmethodID in the existing cache or we have a new
// cache or we just grew the cache. This cache write is done here
// by the first thread to win the foot race because a jmethodID
// needs to be unique once it is generally available.
id = new_id;
// The jmethodID cache can be read while unlocked so we have to
// make sure the new jmethodID is complete before installing it
// in the cache.
OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
} else {
*to_dealloc_id_p = new_id; // save new id for later delete
}
return id;
}
// Common code to get the jmethodID cache length and the jmethodID
// value at index idnum if there is one.
//
void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
size_t idnum, size_t *length_p, jmethodID* id_p) {
assert(cache != NULL, "sanity check");
assert(length_p != NULL, "sanity check");
assert(id_p != NULL, "sanity check");
// cache size is stored in element[0], other elements offset by one
*length_p = (size_t)cache[0];
if (*length_p <= idnum) { // cache is too short
*id_p = NULL;
} else {
*id_p = cache[idnum+1]; // fetch jmethodID (if any)
}
}
// Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
size_t idnum = (size_t)method->method_idnum();
jmethodID* jmeths = methods_jmethod_ids_acquire();
size_t length; // length assigned as debugging crumb
jmethodID id = NULL;
if (jmeths != NULL && // If there is a cache
(length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
id = jmeths[idnum+1]; // Look up the id (may be NULL)
}
return id;
}
int nmethodBucket::decrement() {
return Atomic::add(-1, (volatile int *)&_count);
}
//
// Walk the list of dependent nmethods searching for nmethods which
// are dependent on the changes that were passed in and mark them for
// deoptimization. Returns the number of nmethods found.
//
int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
assert_locked_or_safepoint(CodeCache_lock);
int found = 0;
nmethodBucket* b = _dependencies;
while (b != NULL) {
nmethod* nm = b->get_nmethod();
// since dependencies aren't removed until an nmethod becomes a zombie,
// the dependency list may contain nmethods which aren't alive.
if (b->count() > 0 && nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
if (TraceDependencies) {
ResourceMark rm;
tty->print_cr("Marked for deoptimization");
tty->print_cr(" context = %s", this->external_name());
changes.print();
nm->print();
nm->print_dependencies();
}
nm->mark_for_deoptimization();
found++;
}
b = b->next();
}
return found;
}
void InstanceKlass::clean_dependent_nmethods() {
assert_locked_or_safepoint(CodeCache_lock);
if (has_unloaded_dependent()) {
nmethodBucket* b = _dependencies;
nmethodBucket* last = NULL;
while (b != NULL) {
assert(b->count() >= 0, err_msg("bucket count: %d", b->count()));
nmethodBucket* next = b->next();
if (b->count() == 0) {
if (last == NULL) {
_dependencies = next;
} else {
last->set_next(next);
}
delete b;
// last stays the same.
} else {
last = b;
}
b = next;
}
set_has_unloaded_dependent(false);
}
#ifdef ASSERT
else {
// Verification
for (nmethodBucket* b = _dependencies; b != NULL; b = b->next()) {
assert(b->count() >= 0, err_msg("bucket count: %d", b->count()));
assert(b->count() != 0, "empty buckets need to be cleaned");
}
}
#endif
}
//
// Add an nmethodBucket to the list of dependencies for this nmethod.
// It's possible that an nmethod has multiple dependencies on this klass
// so a count is kept for each bucket to guarantee that creation and
// deletion of dependencies is consistent.
//
void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
assert_locked_or_safepoint(CodeCache_lock);
nmethodBucket* b = _dependencies;
nmethodBucket* last = NULL;
while (b != NULL) {
if (nm == b->get_nmethod()) {
b->increment();
return;
}
b = b->next();
}
_dependencies = new nmethodBucket(nm, _dependencies);
}
//
// Decrement count of the nmethod in the dependency list and remove
// the bucket competely when the count goes to 0. This method must
// find a corresponding bucket otherwise there's a bug in the
// recording of dependecies.
//
void InstanceKlass::remove_dependent_nmethod(nmethod* nm, bool delete_immediately) {
assert_locked_or_safepoint(CodeCache_lock);
nmethodBucket* b = _dependencies;
nmethodBucket* last = NULL;
while (b != NULL) {
if (nm == b->get_nmethod()) {
int val = b->decrement();
guarantee(val >= 0, err_msg("Underflow: %d", val));
if (val == 0) {
if (delete_immediately) {
if (last == NULL) {
_dependencies = b->next();
} else {
last->set_next(b->next());
}
delete b;
} else {
// The deletion of this entry is deferred until a later, potentially parallel GC phase.
set_has_unloaded_dependent(true);
}
}
return;
}
last = b;
b = b->next();
}
#ifdef ASSERT
tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
nm->print();
#endif // ASSERT
ShouldNotReachHere();
}
#ifndef PRODUCT
void InstanceKlass::print_dependent_nmethods(bool verbose) {
nmethodBucket* b = _dependencies;
int idx = 0;
while (b != NULL) {
nmethod* nm = b->get_nmethod();
tty->print("[%d] count=%d { ", idx++, b->count());
if (!verbose) {
nm->print_on(tty, "nmethod");
tty->print_cr(" } ");
} else {
nm->print();
nm->print_dependencies();
tty->print_cr("--- } ");
}
b = b->next();
}
}
bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
nmethodBucket* b = _dependencies;
while (b != NULL) {
if (nm == b->get_nmethod()) {
#ifdef ASSERT
int count = b->count();
assert(count >= 0, err_msg("count shouldn't be negative: %d", count));
#endif
return true;
}
b = b->next();
}
return false;
}
#endif //PRODUCT
// Garbage collection
#ifdef ASSERT
template <class T> void assert_is_in(T *p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
assert(Universe::heap()->is_in(o), "should be in heap");
}
}
template <class T> void assert_is_in_closed_subset(T *p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
assert(Universe::heap()->is_in_closed_subset(o),
err_msg("should be in closed *p " INTPTR_FORMAT " " INTPTR_FORMAT, (address)p, (address)o));
}
}
template <class T> void assert_is_in_reserved(T *p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
}
}
template <class T> void assert_nothing(T *p) {}
#else
template <class T> void assert_is_in(T *p) {}
template <class T> void assert_is_in_closed_subset(T *p) {}
template <class T> void assert_is_in_reserved(T *p) {}
template <class T> void assert_nothing(T *p) {}
#endif // ASSERT
//
// Macros that iterate over areas of oops which are specialized on type of
// oop pointer either narrow or wide, depending on UseCompressedOops
//
// Parameters are:
// T - type of oop to point to (either oop or narrowOop)
// start_p - starting pointer for region to iterate over
// count - number of oops or narrowOops to iterate over
// do_oop - action to perform on each oop (it's arbitrary C code which
// makes it more efficient to put in a macro rather than making
// it a template function)
// assert_fn - assert function which is template function because performance
// doesn't matter when enabled.
#define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
T, start_p, count, do_oop, \
assert_fn) \
{ \
T* p = (T*)(start_p); \
T* const end = p + (count); \
while (p < end) { \
(assert_fn)(p); \
do_oop; \
++p; \
} \
}
#define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
T, start_p, count, do_oop, \
assert_fn) \
{ \
T* const start = (T*)(start_p); \
T* p = start + (count); \
while (start < p) { \
--p; \
(assert_fn)(p); \
do_oop; \
} \
}
#define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
T, start_p, count, low, high, \
do_oop, assert_fn) \
{ \
T* const l = (T*)(low); \
T* const h = (T*)(high); \
assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
mask_bits((intptr_t)h, sizeof(T)-1) == 0, \
"bounded region must be properly aligned"); \
T* p = (T*)(start_p); \
T* end = p + (count); \
if (p < l) p = l; \
if (end > h) end = h; \
while (p < end) { \
(assert_fn)(p); \
do_oop; \
++p; \
} \
}
// The following macros call specialized macros, passing either oop or
// narrowOop as the specialization type. These test the UseCompressedOops
// flag.
#define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn) \
{ \
/* Compute oopmap block range. The common case \
is nonstatic_oop_map_size == 1. */ \
OopMapBlock* map = start_of_nonstatic_oop_maps(); \
OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
if (UseCompressedOops) { \
while (map < end_map) { \
InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop, \
obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
do_oop, assert_fn) \
++map; \
} \
} else { \
while (map < end_map) { \
InstanceKlass_SPECIALIZED_OOP_ITERATE(oop, \
obj->obj_field_addr<oop>(map->offset()), map->count(), \
do_oop, assert_fn) \
++map; \
} \
} \
}
#define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn) \
{ \
OopMapBlock* const start_map = start_of_nonstatic_oop_maps(); \
OopMapBlock* map = start_map + nonstatic_oop_map_count(); \
if (UseCompressedOops) { \
while (start_map < map) { \
--map; \
InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop, \
obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
do_oop, assert_fn) \
} \
} else { \
while (start_map < map) { \
--map; \
InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop, \
obj->obj_field_addr<oop>(map->offset()), map->count(), \
do_oop, assert_fn) \
} \
} \
}
#define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop, \
assert_fn) \
{ \
/* Compute oopmap block range. The common case is \
nonstatic_oop_map_size == 1, so we accept the \
usually non-existent extra overhead of examining \
all the maps. */ \
OopMapBlock* map = start_of_nonstatic_oop_maps(); \
OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
if (UseCompressedOops) { \
while (map < end_map) { \
InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop, \
obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
low, high, \
do_oop, assert_fn) \
++map; \
} \
} else { \
while (map < end_map) { \
InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop, \
obj->obj_field_addr<oop>(map->offset()), map->count(), \
low, high, \
do_oop, assert_fn) \
++map; \
} \
} \
}
void InstanceKlass::oop_follow_contents(oop obj) {
assert(obj != NULL, "can't follow the content of NULL object");
MarkSweep::follow_klass(obj->klass());
InstanceKlass_OOP_MAP_ITERATE( \
obj, \
MarkSweep::mark_and_push(p), \
assert_is_in_closed_subset)
}
#if INCLUDE_ALL_GCS
void InstanceKlass::oop_follow_contents(ParCompactionManager* cm,
oop obj) {
assert(obj != NULL, "can't follow the content of NULL object");
PSParallelCompact::follow_klass(cm, obj->klass());
// Only mark the header and let the scan of the meta-data mark
// everything else.
InstanceKlass_OOP_MAP_ITERATE( \
obj, \
PSParallelCompact::mark_and_push(cm, p), \
assert_is_in)
}
#endif // INCLUDE_ALL_GCS
// closure's do_metadata() method dictates whether the given closure should be
// applied to the klass ptr in the object header.
#define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
\
int InstanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
/* header */ \
if_do_metadata_checked(closure, nv_suffix) { \
closure->do_klass##nv_suffix(obj->klass()); \
} \
InstanceKlass_OOP_MAP_ITERATE( \
obj, \
SpecializationStats:: \
record_do_oop_call##nv_suffix(SpecializationStats::ik); \
(closure)->do_oop##nv_suffix(p), \
assert_is_in_closed_subset) \
return size_helper(); \
}
#if INCLUDE_ALL_GCS
#define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
\
int InstanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj, \
OopClosureType* closure) { \
SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
\
assert_should_ignore_metadata(closure, nv_suffix); \
\
/* instance variables */ \
InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
obj, \
SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
(closure)->do_oop##nv_suffix(p), \
assert_is_in_closed_subset) \
return size_helper(); \
}
#endif // INCLUDE_ALL_GCS
#define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
\
int InstanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj, \
OopClosureType* closure, \
MemRegion mr) { \
SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
if_do_metadata_checked(closure, nv_suffix) { \
if (mr.contains(obj)) { \
closure->do_klass##nv_suffix(obj->klass()); \
} \
} \
InstanceKlass_BOUNDED_OOP_MAP_ITERATE( \
obj, mr.start(), mr.end(), \
(closure)->do_oop##nv_suffix(p), \
assert_is_in_closed_subset) \
return size_helper(); \
}
ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
#if INCLUDE_ALL_GCS
ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
#endif // INCLUDE_ALL_GCS
int InstanceKlass::oop_adjust_pointers(oop obj) {
int size = size_helper();
InstanceKlass_OOP_MAP_ITERATE( \
obj, \
MarkSweep::adjust_pointer(p), \
assert_is_in)
return size;
}
#if INCLUDE_ALL_GCS
void InstanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
obj, \
if (PSScavenge::should_scavenge(p)) { \
pm->claim_or_forward_depth(p); \
}, \
assert_nothing )
}
int InstanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
int size = size_helper();
InstanceKlass_OOP_MAP_ITERATE( \
obj, \
PSParallelCompact::adjust_pointer(p), \
assert_is_in)
return size;
}
#endif // INCLUDE_ALL_GCS
void InstanceKlass::clean_weak_instanceklass_links(BoolObjectClosure* is_alive) {
clean_implementors_list(is_alive);
clean_method_data(is_alive);
clean_dependent_nmethods();
}
void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
assert(class_loader_data()->is_alive(is_alive), "this klass should be live");
if (is_interface()) {
if (ClassUnloading) {
Klass* impl = implementor();
if (impl != NULL) {
if (!impl->is_loader_alive(is_alive)) {
// remove this guy
Klass** klass = adr_implementor();
assert(klass != NULL, "null klass");
if (klass != NULL) {
*klass = NULL;
}
}
}
}
}
}
void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
for (int m = 0; m < methods()->length(); m++) {
MethodData* mdo = methods()->at(m)->method_data();
if (mdo != NULL) {
mdo->clean_method_data(is_alive);
}
}
}
static void remove_unshareable_in_class(Klass* k) {
// remove klass's unshareable info
k->remove_unshareable_info();
}
void InstanceKlass::remove_unshareable_info() {
Klass::remove_unshareable_info();
// Unlink the class
if (is_linked()) {
unlink_class();
}
init_implementor();
constants()->remove_unshareable_info();
for (int i = 0; i < methods()->length(); i++) {
Method* m = methods()->at(i);
m->remove_unshareable_info();
}
// do array classes also.
array_klasses_do(remove_unshareable_in_class);
}
static void restore_unshareable_in_class(Klass* k, TRAPS) {
// Array classes have null protection domain.
// --> see ArrayKlass::complete_create_array_klass()
k->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
}
void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
instanceKlassHandle ik(THREAD, this);
Array<Method*>* methods = ik->methods();
int num_methods = methods->length();
for (int index2 = 0; index2 < num_methods; ++index2) {
methodHandle m(THREAD, methods->at(index2));
m->restore_unshareable_info(CHECK);
}
if (JvmtiExport::has_redefined_a_class()) {
// Reinitialize vtable because RedefineClasses may have changed some
// entries in this vtable for super classes so the CDS vtable might
// point to old or obsolete entries. RedefineClasses doesn't fix up
// vtables in the shared system dictionary, only the main one.
// It also redefines the itable too so fix that too.
ResourceMark rm(THREAD);
ik->vtable()->initialize_vtable(false, CHECK);
ik->itable()->initialize_itable(false, CHECK);
}
// restore constant pool resolved references
ik->constants()->restore_unshareable_info(CHECK);
ik->array_klasses_do(restore_unshareable_in_class, CHECK);
}
// returns true IFF is_in_error_state() has been changed as a result of this call.
bool InstanceKlass::check_sharing_error_state() {
assert(DumpSharedSpaces, "should only be called during dumping");
bool old_state = is_in_error_state();
if (!is_in_error_state()) {
bool bad = false;
for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
if (sup->is_in_error_state()) {
bad = true;
break;
}
}
if (!bad) {
Array<Klass*>* interfaces = transitive_interfaces();
for (int i = 0; i < interfaces->length(); i++) {
Klass* iface = interfaces->at(i);
if (InstanceKlass::cast(iface)->is_in_error_state()) {
bad = true;
break;
}
}
}
if (bad) {
set_in_error_state();
}
}
return (old_state != is_in_error_state());
}
static void clear_all_breakpoints(Method* m) {
m->clear_all_breakpoints();
}
void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
// notify the debugger
if (JvmtiExport::should_post_class_unload()) {
JvmtiExport::post_class_unload(ik);
}
// notify ClassLoadingService of class unload
ClassLoadingService::notify_class_unloaded(ik);
#if INCLUDE_JFR
assert(ik != NULL, "invariant");
EventClassUnload event;
event.set_unloadedClass(ik);
event.set_definingClassLoader(ik->class_loader_data());
event.commit();
#endif
}
void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
// Clean up C heap
ik->release_C_heap_structures();
ik->constants()->release_C_heap_structures();
}
void InstanceKlass::release_C_heap_structures() {
// Can't release the constant pool here because the constant pool can be
// deallocated separately from the InstanceKlass for default methods and
// redefine classes.
// Deallocate oop map cache
if (_oop_map_cache != NULL) {
delete _oop_map_cache;
_oop_map_cache = NULL;
}
// Deallocate JNI identifiers for jfieldIDs
JNIid::deallocate(jni_ids());
set_jni_ids(NULL);
jmethodID* jmeths = methods_jmethod_ids_acquire();
if (jmeths != (jmethodID*)NULL) {
release_set_methods_jmethod_ids(NULL);
FreeHeap(jmeths);
}
// Deallocate MemberNameTable
{
Mutex* lock_or_null = SafepointSynchronize::is_at_safepoint() ? NULL : MemberNameTable_lock;
MutexLockerEx ml(lock_or_null, Mutex::_no_safepoint_check_flag);
MemberNameTable* mnt = member_names();
if (mnt != NULL) {
delete mnt;
set_member_names(NULL);
}
}
// release dependencies
nmethodBucket* b = _dependencies;
_dependencies = NULL;
while (b != NULL) {
nmethodBucket* next = b->next();
delete b;
b = next;
}
// Deallocate breakpoint records
if (breakpoints() != 0x0) {
methods_do(clear_all_breakpoints);
assert(breakpoints() == 0x0, "should have cleared breakpoints");
}
// deallocate the cached class file
if (_cached_class_file != NULL) {
os::free(_cached_class_file, mtClass);
_cached_class_file = NULL;
}
// Decrement symbol reference counts associated with the unloaded class.
if (_name != NULL) _name->decrement_refcount();
// unreference array name derived from this class name (arrays of an unloaded
// class can't be referenced anymore).
if (_array_name != NULL) _array_name->decrement_refcount();
if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension, mtClass);
assert(_total_instanceKlass_count >= 1, "Sanity check");
Atomic::dec(&_total_instanceKlass_count);
}
void InstanceKlass::set_source_debug_extension(char* array, int length) {
if (array == NULL) {
_source_debug_extension = NULL;
} else {
// Adding one to the attribute length in order to store a null terminator
// character could cause an overflow because the attribute length is
// already coded with an u4 in the classfile, but in practice, it's
// unlikely to happen.
assert((length+1) > length, "Overflow checking");
char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
for (int i = 0; i < length; i++) {
sde[i] = array[i];
}
sde[length] = '\0';
_source_debug_extension = sde;
}
}
address InstanceKlass::static_field_addr(int offset) {
return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + cast_from_oop<intptr_t>(java_mirror()));
}
const char* InstanceKlass::signature_name() const {
int hash_len = 0;
char hash_buf[40];
// If this is an anonymous class, append a hash to make the name unique
if (is_anonymous()) {
assert(EnableInvokeDynamic, "EnableInvokeDynamic was not set.");
intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
sprintf(hash_buf, "/" UINTX_FORMAT, (uintx)hash);
hash_len = (int)strlen(hash_buf);
}
// Get the internal name as a c string
const char* src = (const char*) (name()->as_C_string());
const int src_length = (int)strlen(src);
char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
// Add L as type indicator
int dest_index = 0;
dest[dest_index++] = 'L';
// Add the actual class name
for (int src_index = 0; src_index < src_length; ) {
dest[dest_index++] = src[src_index++];
}
// If we have a hash, append it
for (int hash_index = 0; hash_index < hash_len; ) {
dest[dest_index++] = hash_buf[hash_index++];
}
// Add the semicolon and the NULL
dest[dest_index++] = ';';
dest[dest_index] = '\0';
return dest;
}
// different verisons of is_same_class_package
bool InstanceKlass::is_same_class_package(Klass* class2) {
Klass* class1 = this;
oop classloader1 = InstanceKlass::cast(class1)->class_loader();
Symbol* classname1 = class1->name();
if (class2->oop_is_objArray()) {
class2 = ObjArrayKlass::cast(class2)->bottom_klass();
}
oop classloader2;
if (class2->oop_is_instance()) {
classloader2 = InstanceKlass::cast(class2)->class_loader();
} else {
assert(class2->oop_is_typeArray(), "should be type array");
classloader2 = NULL;
}
Symbol* classname2 = class2->name();
return InstanceKlass::is_same_class_package(classloader1, classname1,
classloader2, classname2);
}
bool InstanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
Klass* class1 = this;
oop classloader1 = InstanceKlass::cast(class1)->class_loader();
Symbol* classname1 = class1->name();
return InstanceKlass::is_same_class_package(classloader1, classname1,
classloader2, classname2);
}
// return true if two classes are in the same package, classloader
// and classname information is enough to determine a class's package
bool InstanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
oop class_loader2, Symbol* class_name2) {
if (class_loader1 != class_loader2) {
return false;
} else if (class_name1 == class_name2) {
return true; // skip painful bytewise comparison
} else {
ResourceMark rm;
// The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
// for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
// Otherwise, we just compare jbyte values between the strings.
const jbyte *name1 = class_name1->base();
const jbyte *name2 = class_name2->base();
const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
// One of the two doesn't have a package. Only return true
// if the other one also doesn't have a package.
return last_slash1 == last_slash2;
} else {
// Skip over '['s
if (*name1 == '[') {
do {
name1++;
} while (*name1 == '[');
if (*name1 != 'L') {
// Something is terribly wrong. Shouldn't be here.
return false;
}
}
if (*name2 == '[') {
do {
name2++;
} while (*name2 == '[');
if (*name2 != 'L') {
// Something is terribly wrong. Shouldn't be here.
return false;
}
}
// Check that package part is identical
int length1 = last_slash1 - name1;
int length2 = last_slash2 - name2;
return UTF8::equal(name1, length1, name2, length2);
}
}
}
// Returns true iff super_method can be overridden by a method in targetclassname
// See JSL 3rd edition 8.4.6.1
// Assumes name-signature match
// "this" is InstanceKlass of super_method which must exist
// note that the InstanceKlass of the method in the targetclassname has not always been created yet
bool InstanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
// Private methods can not be overridden
if (super_method->is_private()) {
return false;
}
// If super method is accessible, then override
if ((super_method->is_protected()) ||
(super_method->is_public())) {
return true;
}
// Package-private methods are not inherited outside of package
assert(super_method->is_package_private(), "must be package private");
return(is_same_class_package(targetclassloader(), targetclassname));
}
/* defined for now in jvm.cpp, for historical reasons *--
Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
Symbol*& simple_name_result, TRAPS) {
...
}
*/
// tell if two classes have the same enclosing class (at package level)
bool InstanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
Klass* class2_oop, TRAPS) {
if (class2_oop == class1()) return true;
if (!class2_oop->oop_is_instance()) return false;
instanceKlassHandle class2(THREAD, class2_oop);
// must be in same package before we try anything else
if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
return false;
// As long as there is an outer1.getEnclosingClass,
// shift the search outward.
instanceKlassHandle outer1 = class1;
for (;;) {
// As we walk along, look for equalities between outer1 and class2.
// Eventually, the walks will terminate as outer1 stops
// at the top-level class around the original class.
bool ignore_inner_is_member;
Klass* next = outer1->compute_enclosing_class(&ignore_inner_is_member,
CHECK_false);
if (next == NULL) break;
if (next == class2()) return true;
outer1 = instanceKlassHandle(THREAD, next);
}
// Now do the same for class2.
instanceKlassHandle outer2 = class2;
for (;;) {
bool ignore_inner_is_member;
Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
CHECK_false);
if (next == NULL) break;
// Might as well check the new outer against all available values.
if (next == class1()) return true;
if (next == outer1()) return true;
outer2 = instanceKlassHandle(THREAD, next);
}
// If by this point we have not found an equality between the
// two classes, we know they are in separate package members.
return false;
}
jint InstanceKlass::compute_modifier_flags(TRAPS) const {
jint access = access_flags().as_int();
// But check if it happens to be member class.
instanceKlassHandle ik(THREAD, this);
InnerClassesIterator iter(ik);
for (; !iter.done(); iter.next()) {
int ioff = iter.inner_class_info_index();
// Inner class attribute can be zero, skip it.
// Strange but true: JVM spec. allows null inner class refs.
if (ioff == 0) continue;
// only look at classes that are already loaded
// since we are looking for the flags for our self.
Symbol* inner_name = ik->constants()->klass_name_at(ioff);
if ((ik->name() == inner_name)) {
// This is really a member class.
access = iter.inner_access_flags();
break;
}
}
// Remember to strip ACC_SUPER bit
return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
}
jint InstanceKlass::jvmti_class_status() const {
jint result = 0;
if (is_linked()) {
result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
}
if (is_initialized()) {
assert(is_linked(), "Class status is not consistent");
result |= JVMTI_CLASS_STATUS_INITIALIZED;
}
if (is_in_error_state()) {
result |= JVMTI_CLASS_STATUS_ERROR;
}
return result;
}
Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
int method_table_offset_in_words = ioe->offset()/wordSize;
int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
/ itableOffsetEntry::size();
for (int cnt = 0 ; ; cnt ++, ioe ++) {
// If the interface isn't implemented by the receiver class,
// the VM should throw IncompatibleClassChangeError.
if (cnt >= nof_interfaces) {
THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
}
Klass* ik = ioe->interface_klass();
if (ik == holder) break;
}
itableMethodEntry* ime = ioe->first_method_entry(this);
Method* m = ime[index].method();
if (m == NULL) {
THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
}
return m;
}
#if INCLUDE_JVMTI
// update default_methods for redefineclasses for methods that are
// not yet in the vtable due to concurrent subclass define and superinterface
// redefinition
// Note: those in the vtable, should have been updated via adjust_method_entries
void InstanceKlass::adjust_default_methods(InstanceKlass* holder, bool* trace_name_printed) {
// search the default_methods for uses of either obsolete or EMCP methods
if (default_methods() != NULL) {
for (int index = 0; index < default_methods()->length(); index ++) {
Method* old_method = default_methods()->at(index);
if (old_method == NULL || old_method->method_holder() != holder || !old_method->is_old()) {
continue; // skip uninteresting entries
}
assert(!old_method->is_deleted(), "default methods may not be deleted");
Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
assert(new_method != NULL, "method_with_idnum() should not be NULL");
assert(old_method != new_method, "sanity check");
default_methods()->at_put(index, new_method);
if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
if (!(*trace_name_printed)) {
// RC_TRACE_MESG macro has an embedded ResourceMark
RC_TRACE_MESG(("adjust: klassname=%s default methods from name=%s",
external_name(),
old_method->method_holder()->external_name()));
*trace_name_printed = true;
}
RC_TRACE(0x00100000, ("default method update: %s(%s) ",
new_method->name()->as_C_string(),
new_method->signature()->as_C_string()));
}
}
}
}
#endif // INCLUDE_JVMTI
// On-stack replacement stuff
void InstanceKlass::add_osr_nmethod(nmethod* n) {
#ifndef PRODUCT
if (TieredCompilation) {
nmethod * prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
assert(prev == NULL || !prev->is_in_use(),
"redundunt OSR recompilation detected. memory leak in CodeCache!");
}
#endif
// only one compilation can be active
NEEDS_CLEANUP
// This is a short non-blocking critical region, so the no safepoint check is ok.
OsrList_lock->lock_without_safepoint_check();
assert(n->is_osr_method(), "wrong kind of nmethod");
n->set_osr_link(osr_nmethods_head());
set_osr_nmethods_head(n);
// Raise the highest osr level if necessary
if (TieredCompilation) {
Method* m = n->method();
m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
}
// Remember to unlock again
OsrList_lock->unlock();
// Get rid of the osr methods for the same bci that have lower levels.
if (TieredCompilation) {
for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
if (inv != NULL && inv->is_in_use()) {
inv->make_not_entrant();
}
}
}
}
void InstanceKlass::remove_osr_nmethod(nmethod* n) {
// This is a short non-blocking critical region, so the no safepoint check is ok.
OsrList_lock->lock_without_safepoint_check();
assert(n->is_osr_method(), "wrong kind of nmethod");
nmethod* last = NULL;
nmethod* cur = osr_nmethods_head();
int max_level = CompLevel_none; // Find the max comp level excluding n
Method* m = n->method();
// Search for match
while(cur != NULL && cur != n) {
if (TieredCompilation && m == cur->method()) {
// Find max level before n
max_level = MAX2(max_level, cur->comp_level());
}
last = cur;
cur = cur->osr_link();
}
nmethod* next = NULL;
if (cur == n) {
next = cur->osr_link();
if (last == NULL) {
// Remove first element
set_osr_nmethods_head(next);
} else {
last->set_osr_link(next);
}
}
n->set_osr_link(NULL);
if (TieredCompilation) {
cur = next;
while (cur != NULL) {
// Find max level after n
if (m == cur->method()) {
max_level = MAX2(max_level, cur->comp_level());
}
cur = cur->osr_link();
}
m->set_highest_osr_comp_level(max_level);
}
// Remember to unlock again
OsrList_lock->unlock();
}
int InstanceKlass::mark_osr_nmethods(const Method* m) {
// This is a short non-blocking critical region, so the no safepoint check is ok.
MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
nmethod* osr = osr_nmethods_head();
int found = 0;
while (osr != NULL) {
assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
if (osr->method() == m) {
osr->mark_for_deoptimization();
found++;
}
osr = osr->osr_link();
}
return found;
}
nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
// This is a short non-blocking critical region, so the no safepoint check is ok.
OsrList_lock->lock_without_safepoint_check();
nmethod* osr = osr_nmethods_head();
nmethod* best = NULL;
while (osr != NULL) {
assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
// There can be a time when a c1 osr method exists but we are waiting
// for a c2 version. When c2 completes its osr nmethod we will trash
// the c1 version and only be able to find the c2 version. However
// while we overflow in the c1 code at back branches we don't want to
// try and switch to the same code as we are already running
if (osr->method() == m &&
(bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
if (match_level) {
if (osr->comp_level() == comp_level) {
// Found a match - return it.
OsrList_lock->unlock();
return osr;
}
} else {
if (best == NULL || (osr->comp_level() > best->comp_level())) {
if (osr->comp_level() == CompLevel_highest_tier) {
// Found the best possible - return it.
OsrList_lock->unlock();
return osr;
}
best = osr;
}
}
}
osr = osr->osr_link();
}
OsrList_lock->unlock();
assert(match_level == false || best == NULL, "shouldn't pick up anything if match_level is set");
if (best != NULL && best->comp_level() >= comp_level) {
return best;
}
return NULL;
}
oop InstanceKlass::add_member_name(Handle mem_name, bool intern) {
jweak mem_name_wref = JNIHandles::make_weak_global(mem_name);
MutexLocker ml(MemberNameTable_lock);
DEBUG_ONLY(No_Safepoint_Verifier nsv);
// Check if method has been redefined while taking out MemberNameTable_lock, if so
// return false. We cannot cache obsolete methods. They will crash when the function
// is called!
Method* method = (Method*)java_lang_invoke_MemberName::vmtarget(mem_name());
if (method->is_obsolete()) {
return NULL;
} else if (method->is_old()) {
// Replace method with redefined version
java_lang_invoke_MemberName::set_vmtarget(mem_name(), method_with_idnum(method->method_idnum()));
}
if (_member_names == NULL) {
_member_names = new (ResourceObj::C_HEAP, mtClass) MemberNameTable(idnum_allocated_count());
}
if (intern) {
return _member_names->find_or_add_member_name(mem_name_wref);
} else {
return _member_names->add_member_name(mem_name_wref);
}
}
// -----------------------------------------------------------------------------------------------------
// Printing
#ifndef PRODUCT
#define BULLET " - "
static const char* state_names[] = {
"allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
};
static void print_vtable(intptr_t* start, int len, outputStream* st) {
for (int i = 0; i < len; i++) {
intptr_t e = start[i];
st->print("%d : " INTPTR_FORMAT, i, e);
if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
st->print(" ");
((Metadata*)e)->print_value_on(st);
}
st->cr();
}
}
void InstanceKlass::print_on(outputStream* st) const {
assert(is_klass(), "must be klass");
Klass::print_on(st);
st->print(BULLET"instance size: %d", size_helper()); st->cr();
st->print(BULLET"klass size: %d", size()); st->cr();
st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
st->print(BULLET"state: "); st->print_cr("%s", state_names[_init_state]);
st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
st->print(BULLET"super: "); super()->print_value_on_maybe_null(st); st->cr();
st->print(BULLET"sub: ");
Klass* sub = subklass();
int n;
for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
if (n < MaxSubklassPrintSize) {
sub->print_value_on(st);
st->print(" ");
}
}
if (n >= MaxSubklassPrintSize) st->print("(%d more klasses...)", n - MaxSubklassPrintSize);
st->cr();
if (is_interface()) {
st->print_cr(BULLET"nof implementors: %d", nof_implementors());
if (nof_implementors() == 1) {
st->print_cr(BULLET"implementor: ");
st->print(" ");
implementor()->print_value_on(st);
st->cr();
}
}
st->print(BULLET"arrays: "); array_klasses()->print_value_on_maybe_null(st); st->cr();
st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
if (Verbose || WizardMode) {
Array<Method*>* method_array = methods();
for (int i = 0; i < method_array->length(); i++) {
st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
}
}
st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
if (Verbose && default_methods() != NULL) {
Array<Method*>* method_array = default_methods();
for (int i = 0; i < method_array->length(); i++) {
st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
}
}
if (default_vtable_indices() != NULL) {
st->print(BULLET"default vtable indices: "); default_vtable_indices()->print_value_on(st); st->cr();
}
st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
if (class_loader_data() != NULL) {
st->print(BULLET"class loader data: ");
class_loader_data()->print_value_on(st);
st->cr();
}
st->print(BULLET"host class: "); host_klass()->print_value_on_maybe_null(st); st->cr();
if (source_file_name() != NULL) {
st->print(BULLET"source file: ");
source_file_name()->print_value_on(st);
st->cr();
}
if (source_debug_extension() != NULL) {
st->print(BULLET"source debug extension: ");
st->print("%s", source_debug_extension());
st->cr();
}
st->print(BULLET"class annotations: "); class_annotations()->print_value_on(st); st->cr();
st->print(BULLET"class type annotations: "); class_type_annotations()->print_value_on(st); st->cr();
st->print(BULLET"field annotations: "); fields_annotations()->print_value_on(st); st->cr();
st->print(BULLET"field type annotations: "); fields_type_annotations()->print_value_on(st); st->cr();
{
bool have_pv = false;
// previous versions are linked together through the InstanceKlass
for (InstanceKlass* pv_node = _previous_versions;
pv_node != NULL;
pv_node = pv_node->previous_versions()) {
if (!have_pv)
st->print(BULLET"previous version: ");
have_pv = true;
pv_node->constants()->print_value_on(st);
}
if (have_pv) st->cr();
}
if (generic_signature() != NULL) {
st->print(BULLET"generic signature: ");
generic_signature()->print_value_on(st);
st->cr();
}
st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
st->print(BULLET"java mirror: "); java_mirror()->print_value_on(st); st->cr();
st->print(BULLET"vtable length %d (start addr: " INTPTR_FORMAT ")", vtable_length(), start_of_vtable()); st->cr();
if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
st->print(BULLET"itable length %d (start addr: " INTPTR_FORMAT ")", itable_length(), start_of_itable()); st->cr();
if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
FieldPrinter print_static_field(st);
((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
FieldPrinter print_nonstatic_field(st);
((InstanceKlass*)this)->do_nonstatic_fields(&print_nonstatic_field);
st->print(BULLET"non-static oop maps: ");
OopMapBlock* map = start_of_nonstatic_oop_maps();
OopMapBlock* end_map = map + nonstatic_oop_map_count();
while (map < end_map) {
st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
map++;
}
st->cr();
}
#endif //PRODUCT
void InstanceKlass::print_value_on(outputStream* st) const {
assert(is_klass(), "must be klass");
if (Verbose || WizardMode) access_flags().print_on(st);
name()->print_value_on(st);
}
#ifndef PRODUCT
void FieldPrinter::do_field(fieldDescriptor* fd) {
_st->print(BULLET);
if (_obj == NULL) {
fd->print_on(_st);
_st->cr();
} else {
fd->print_on_for(_st, _obj);
_st->cr();
}
}
void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
Klass::oop_print_on(obj, st);
if (this == SystemDictionary::String_klass()) {
typeArrayOop value = java_lang_String::value(obj);
juint offset = java_lang_String::offset(obj);
juint length = java_lang_String::length(obj);
if (value != NULL &&
value->is_typeArray() &&
offset <= (juint) value->length() &&
offset + length <= (juint) value->length()) {
st->print(BULLET"string: ");
java_lang_String::print(obj, st);
st->cr();
if (!WizardMode) return; // that is enough
}
}
st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
FieldPrinter print_field(st, obj);
do_nonstatic_fields(&print_field);
if (this == SystemDictionary::Class_klass()) {
st->print(BULLET"signature: ");
java_lang_Class::print_signature(obj, st);
st->cr();
Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
st->print(BULLET"fake entry for mirror: ");
mirrored_klass->print_value_on_maybe_null(st);
st->cr();
Klass* array_klass = java_lang_Class::array_klass(obj);
st->print(BULLET"fake entry for array: ");
array_klass->print_value_on_maybe_null(st);
st->cr();
st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
Klass* real_klass = java_lang_Class::as_Klass(obj);
if (real_klass != NULL && real_klass->oop_is_instance()) {
InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
}
} else if (this == SystemDictionary::MethodType_klass()) {
st->print(BULLET"signature: ");
java_lang_invoke_MethodType::print_signature(obj, st);
st->cr();
}
}
#endif //PRODUCT
void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
st->print("a ");
name()->print_value_on(st);
obj->print_address_on(st);
if (this == SystemDictionary::String_klass()
&& java_lang_String::value(obj) != NULL) {
ResourceMark rm;
int len = java_lang_String::length(obj);
int plen = (len < 24 ? len : 12);
char* str = java_lang_String::as_utf8_string(obj, 0, plen);
st->print(" = \"%s\"", str);
if (len > plen)
st->print("...[%d]", len);
} else if (this == SystemDictionary::Class_klass()) {
Klass* k = java_lang_Class::as_Klass(obj);
st->print(" = ");
if (k != NULL) {
k->print_value_on(st);
} else {
const char* tname = type2name(java_lang_Class::primitive_type(obj));
st->print("%s", tname ? tname : "type?");
}
} else if (this == SystemDictionary::MethodType_klass()) {
st->print(" = ");
java_lang_invoke_MethodType::print_signature(obj, st);
} else if (java_lang_boxing_object::is_instance(obj)) {
st->print(" = ");
java_lang_boxing_object::print(obj, st);
} else if (this == SystemDictionary::LambdaForm_klass()) {
oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
if (vmentry != NULL) {
st->print(" => ");
vmentry->print_value_on(st);
}
} else if (this == SystemDictionary::MemberName_klass()) {
Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
if (vmtarget != NULL) {
st->print(" = ");
vmtarget->print_value_on(st);
} else {
java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
st->print(".");
java_lang_invoke_MemberName::name(obj)->print_value_on(st);
}
}
}
const char* InstanceKlass::internal_name() const {
return external_name();
}
#if INCLUDE_SERVICES
// Size Statistics
void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
Klass::collect_statistics(sz);
sz->_inst_size = HeapWordSize * size_helper();
sz->_vtab_bytes = HeapWordSize * align_object_offset(vtable_length());
sz->_itab_bytes = HeapWordSize * align_object_offset(itable_length());
sz->_nonstatic_oopmap_bytes = HeapWordSize *
((is_interface() || is_anonymous()) ?
align_object_offset(nonstatic_oop_map_size()) :
nonstatic_oop_map_size());
int n = 0;
n += (sz->_methods_array_bytes = sz->count_array(methods()));
n += (sz->_method_ordering_bytes = sz->count_array(method_ordering()));
n += (sz->_local_interfaces_bytes = sz->count_array(local_interfaces()));
n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
n += (sz->_fields_bytes = sz->count_array(fields()));
n += (sz->_inner_classes_bytes = sz->count_array(inner_classes()));
sz->_ro_bytes += n;
const ConstantPool* cp = constants();
if (cp) {
cp->collect_statistics(sz);
}
const Annotations* anno = annotations();
if (anno) {
anno->collect_statistics(sz);
}
const Array<Method*>* methods_array = methods();
if (methods()) {
for (int i = 0; i < methods_array->length(); i++) {
Method* method = methods_array->at(i);
if (method) {
sz->_method_count ++;
method->collect_statistics(sz);
}
}
}
}
#endif // INCLUDE_SERVICES
// Verification
class VerifyFieldClosure: public OopClosure {
protected:
template <class T> void do_oop_work(T* p) {
oop obj = oopDesc::load_decode_heap_oop(p);
if (!obj->is_oop_or_null()) {
tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
Universe::print();
guarantee(false, "boom");
}
}
public:
virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
};
void InstanceKlass::verify_on(outputStream* st) {
#ifndef PRODUCT
// Avoid redundant verifies, this really should be in product.
if (_verify_count == Universe::verify_count()) return;
_verify_count = Universe::verify_count();
#endif
// Verify Klass
Klass::verify_on(st);
// Verify that klass is present in ClassLoaderData
guarantee(class_loader_data()->contains_klass(this),
"this class isn't found in class loader data");
// Verify vtables
if (is_linked()) {
ResourceMark rm;
// $$$ This used to be done only for m/s collections. Doing it
// always seemed a valid generalization. (DLD -- 6/00)
vtable()->verify(st);
}
// Verify first subklass
if (subklass_oop() != NULL) {
guarantee(subklass_oop()->is_klass(), "should be klass");
}
// Verify siblings
Klass* super = this->super();
Klass* sib = next_sibling();
if (sib != NULL) {
if (sib == this) {
fatal(err_msg("subclass points to itself " PTR_FORMAT, sib));
}
guarantee(sib->is_klass(), "should be klass");
guarantee(sib->super() == super, "siblings should have same superklass");
}
// Verify implementor fields
Klass* im = implementor();
if (im != NULL) {
guarantee(is_interface(), "only interfaces should have implementor set");
guarantee(im->is_klass(), "should be klass");
guarantee(!im->is_interface() || im == this,
"implementors cannot be interfaces");
}
// Verify local interfaces
if (local_interfaces()) {
Array<Klass*>* local_interfaces = this->local_interfaces();
for (int j = 0; j < local_interfaces->length(); j++) {
Klass* e = local_interfaces->at(j);
guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
}
}
// Verify transitive interfaces
if (transitive_interfaces() != NULL) {
Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
for (int j = 0; j < transitive_interfaces->length(); j++) {
Klass* e = transitive_interfaces->at(j);
guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
}
}
// Verify methods
if (methods() != NULL) {
Array<Method*>* methods = this->methods();
for (int j = 0; j < methods->length(); j++) {
guarantee(methods->at(j)->is_method(), "non-method in methods array");
}
for (int j = 0; j < methods->length() - 1; j++) {
Method* m1 = methods->at(j);
Method* m2 = methods->at(j + 1);
guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
}
}
// Verify method ordering
if (method_ordering() != NULL) {
Array<int>* method_ordering = this->method_ordering();
int length = method_ordering->length();
if (JvmtiExport::can_maintain_original_method_order() ||
((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
guarantee(length == methods()->length(), "invalid method ordering length");
jlong sum = 0;
for (int j = 0; j < length; j++) {
int original_index = method_ordering->at(j);
guarantee(original_index >= 0, "invalid method ordering index");
guarantee(original_index < length, "invalid method ordering index");
sum += original_index;
}
// Verify sum of indices 0,1,...,length-1
guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
} else {
guarantee(length == 0, "invalid method ordering length");
}
}
// Verify default methods
if (default_methods() != NULL) {
Array<Method*>* methods = this->default_methods();
for (int j = 0; j < methods->length(); j++) {
guarantee(methods->at(j)->is_method(), "non-method in methods array");
}
for (int j = 0; j < methods->length() - 1; j++) {
Method* m1 = methods->at(j);
Method* m2 = methods->at(j + 1);
guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
}
}
// Verify JNI static field identifiers
if (jni_ids() != NULL) {
jni_ids()->verify(this);
}
// Verify other fields
if (array_klasses() != NULL) {
guarantee(array_klasses()->is_klass(), "should be klass");
}
if (constants() != NULL) {
guarantee(constants()->is_constantPool(), "should be constant pool");
}
const Klass* host = host_klass();
if (host != NULL) {
guarantee(host->is_klass(), "should be klass");
}
}
void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
Klass::oop_verify_on(obj, st);
VerifyFieldClosure blk;
obj->oop_iterate_no_header(&blk);
}
// JNIid class for jfieldIDs only
// Note to reviewers:
// These JNI functions are just moved over to column 1 and not changed
// in the compressed oops workspace.
JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
_holder = holder;
_offset = offset;
_next = next;
debug_only(_is_static_field_id = false;)
}
JNIid* JNIid::find(int offset) {
JNIid* current = this;
while (current != NULL) {
if (current->offset() == offset) return current;
current = current->next();
}
return NULL;
}
void JNIid::deallocate(JNIid* current) {
while (current != NULL) {
JNIid* next = current->next();
delete current;
current = next;
}
}
void JNIid::verify(Klass* holder) {
int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
int end_field_offset;
end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
JNIid* current = this;
while (current != NULL) {
guarantee(current->holder() == holder, "Invalid klass in JNIid");
#ifdef ASSERT
int o = current->offset();
if (current->is_static_field_id()) {
guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
}
#endif
current = current->next();
}
}
#ifdef ASSERT
void InstanceKlass::set_init_state(ClassState state) {
bool good_state = is_shared() ? (_init_state <= state)
: (_init_state < state);
assert(good_state || state == allocated, "illegal state transition");
assert(_init_thread == NULL, "should be cleared before state change");
_init_state = (u1)state;
}
#endif
// RedefineClasses() support for previous versions:
// Purge previous versions
void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
if (ik->previous_versions() != NULL) {
// This klass has previous versions so see what we can cleanup
// while it is safe to do so.
int deleted_count = 0; // leave debugging breadcrumbs
int live_count = 0;
ClassLoaderData* loader_data = ik->class_loader_data();
assert(loader_data != NULL, "should never be null");
// RC_TRACE macro has an embedded ResourceMark
RC_TRACE(0x00000200, ("purge: %s: previous versions", ik->external_name()));
// previous versions are linked together through the InstanceKlass
InstanceKlass* pv_node = ik->previous_versions();
InstanceKlass* last = ik;
int version = 0;
// check the previous versions list
for (; pv_node != NULL; ) {
ConstantPool* pvcp = pv_node->constants();
assert(pvcp != NULL, "cp ref was unexpectedly cleared");
if (!pvcp->on_stack()) {
// If the constant pool isn't on stack, none of the methods
// are executing. Unlink this previous_version.
// The previous version InstanceKlass is on the ClassLoaderData deallocate list
// so will be deallocated during the next phase of class unloading.
pv_node = pv_node->previous_versions();
last->link_previous_versions(pv_node);
deleted_count++;
version++;
continue;
} else {
RC_TRACE(0x00000200, ("purge: previous version " INTPTR_FORMAT " is alive",
pv_node));
assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
live_count++;
}
// At least one method is live in this previous version so clean its MethodData.
// Reset dead EMCP methods not to get breakpoints.
// All methods are deallocated when all of the methods for this class are no
// longer running.
Array<Method*>* method_refs = pv_node->methods();
if (method_refs != NULL) {
RC_TRACE(0x00000200, ("purge: previous methods length=%d",
method_refs->length()));
for (int j = 0; j < method_refs->length(); j++) {
Method* method = method_refs->at(j);
if (!method->on_stack()) {
// no breakpoints for non-running methods
if (method->is_running_emcp()) {
method->set_running_emcp(false);
}
} else {
assert (method->is_obsolete() || method->is_running_emcp(),
"emcp method cannot run after emcp bit is cleared");
// RC_TRACE macro has an embedded ResourceMark
RC_TRACE(0x00000200,
("purge: %s(%s): prev method @%d in version @%d is alive",
method->name()->as_C_string(),
method->signature()->as_C_string(), j, version));
if (method->method_data() != NULL) {
// Clean out any weak method links for running methods
// (also should include not EMCP methods)
method->method_data()->clean_weak_method_links();
}
}
}
}
// next previous version
last = pv_node;
pv_node = pv_node->previous_versions();
version++;
}
RC_TRACE(0x00000200,
("purge: previous version stats: live=%d, deleted=%d", live_count,
deleted_count));
}
// Clean MethodData of this class's methods so they don't refer to
// old methods that are no longer running.
Array<Method*>* methods = ik->methods();
int num_methods = methods->length();
for (int index2 = 0; index2 < num_methods; ++index2) {
if (methods->at(index2)->method_data() != NULL) {
methods->at(index2)->method_data()->clean_weak_method_links();
}
}
}
void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
int emcp_method_count) {
int obsolete_method_count = old_methods->length() - emcp_method_count;
if (emcp_method_count != 0 && obsolete_method_count != 0 &&
_previous_versions != NULL) {
// We have a mix of obsolete and EMCP methods so we have to
// clear out any matching EMCP method entries the hard way.
int local_count = 0;
for (int i = 0; i < old_methods->length(); i++) {
Method* old_method = old_methods->at(i);
if (old_method->is_obsolete()) {
// only obsolete methods are interesting
Symbol* m_name = old_method->name();
Symbol* m_signature = old_method->signature();
// previous versions are linked together through the InstanceKlass
int j = 0;
for (InstanceKlass* prev_version = _previous_versions;
prev_version != NULL;
prev_version = prev_version->previous_versions(), j++) {
Array<Method*>* method_refs = prev_version->methods();
for (int k = 0; k < method_refs->length(); k++) {
Method* method = method_refs->at(k);
if (!method->is_obsolete() &&
method->name() == m_name &&
method->signature() == m_signature) {
// The current RedefineClasses() call has made all EMCP
// versions of this method obsolete so mark it as obsolete
RC_TRACE(0x00000400,
("add: %s(%s): flush obsolete method @%d in version @%d",
m_name->as_C_string(), m_signature->as_C_string(), k, j));
method->set_is_obsolete();
break;
}
}
// The previous loop may not find a matching EMCP method, but
// that doesn't mean that we can optimize and not go any
// further back in the PreviousVersion generations. The EMCP
// method for this generation could have already been made obsolete,
// but there still may be an older EMCP method that has not
// been made obsolete.
}
if (++local_count >= obsolete_method_count) {
// no more obsolete methods so bail out now
break;
}
}
}
}
}
// Save the scratch_class as the previous version if any of the methods are running.
// The previous_versions are used to set breakpoints in EMCP methods and they are
// also used to clean MethodData links to redefined methods that are no longer running.
void InstanceKlass::add_previous_version(instanceKlassHandle scratch_class,
int emcp_method_count) {
assert(Thread::current()->is_VM_thread(),
"only VMThread can add previous versions");
// RC_TRACE macro has an embedded ResourceMark
RC_TRACE(0x00000400, ("adding previous version ref for %s, EMCP_cnt=%d",
scratch_class->external_name(), emcp_method_count));
// Clean out old previous versions
purge_previous_versions(this);
// Mark newly obsolete methods in remaining previous versions. An EMCP method from
// a previous redefinition may be made obsolete by this redefinition.
Array<Method*>* old_methods = scratch_class->methods();
mark_newly_obsolete_methods(old_methods, emcp_method_count);
// If the constant pool for this previous version of the class
// is not marked as being on the stack, then none of the methods
// in this previous version of the class are on the stack so
// we don't need to add this as a previous version.
ConstantPool* cp_ref = scratch_class->constants();
if (!cp_ref->on_stack()) {
RC_TRACE(0x00000400, ("add: scratch class not added; no methods are running"));
return;
}
if (emcp_method_count != 0) {
// At least one method is still running, check for EMCP methods
for (int i = 0; i < old_methods->length(); i++) {
Method* old_method = old_methods->at(i);
if (!old_method->is_obsolete() && old_method->on_stack()) {
// if EMCP method (not obsolete) is on the stack, mark as EMCP so that
// we can add breakpoints for it.
// We set the method->on_stack bit during safepoints for class redefinition and
// class unloading and use this bit to set the is_running_emcp bit.
// After the safepoint, the on_stack bit is cleared and the running emcp
// method may exit. If so, we would set a breakpoint in a method that
// is never reached, but this won't be noticeable to the programmer.
old_method->set_running_emcp(true);
RC_TRACE(0x00000400, ("add: EMCP method %s is on_stack " INTPTR_FORMAT,
old_method->name_and_sig_as_C_string(), old_method));
} else if (!old_method->is_obsolete()) {
RC_TRACE(0x00000400, ("add: EMCP method %s is NOT on_stack " INTPTR_FORMAT,
old_method->name_and_sig_as_C_string(), old_method));
}
}
}
// Add previous version if any methods are still running.
RC_TRACE(0x00000400, ("add: scratch class added; one of its methods is on_stack"));
assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
scratch_class->link_previous_versions(previous_versions());
link_previous_versions(scratch_class());
} // end add_previous_version()
Method* InstanceKlass::method_with_idnum(int idnum) {
Method* m = NULL;
if (idnum < methods()->length()) {
m = methods()->at(idnum);
}
if (m == NULL || m->method_idnum() != idnum) {
for (int index = 0; index < methods()->length(); ++index) {
m = methods()->at(index);
if (m->method_idnum() == idnum) {
return m;
}
}
// None found, return null for the caller to handle.
return NULL;
}
return m;
}
Method* InstanceKlass::method_with_orig_idnum(int idnum) {
if (idnum >= methods()->length()) {
return NULL;
}
Method* m = methods()->at(idnum);
if (m != NULL && m->orig_method_idnum() == idnum) {
return m;
}
// Obsolete method idnum does not match the original idnum
for (int index = 0; index < methods()->length(); ++index) {
m = methods()->at(index);
if (m->orig_method_idnum() == idnum) {
return m;
}
}
// None found, return null for the caller to handle.
return NULL;
}
Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
InstanceKlass* holder = get_klass_version(version);
if (holder == NULL) {
return NULL; // The version of klass is gone, no method is found
}
Method* method = holder->method_with_orig_idnum(idnum);
return method;
}
jint InstanceKlass::get_cached_class_file_len() {
return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
}
unsigned char * InstanceKlass::get_cached_class_file_bytes() {
return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
}
重点从833行开始
InstanceKlass::initialize_impl
void InstanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
// Make sure klass is linked (verified) before initialization
// A class could already be verified, since it has been reflected upon.
this_oop->link_class(CHECK);
DTRACE_CLASSINIT_PROBE(required, InstanceKlass::cast(this_oop()), -1);
bool wait = false;
// refer to the JVM book page 47 for description of steps
// Step 1
{
oop init_lock = this_oop->init_lock();
ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
Thread *self = THREAD; // it's passed the current thread
// Step 2
// If we were to use wait() instead of waitInterruptibly() then
// we might end up throwing IE from link/symbol resolution sites
// that aren't expected to throw. This would wreak havoc. See 6320309.
while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
wait = true;
ol.waitUninterruptibly(CHECK);
}
// Step 3
if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
DTRACE_CLASSINIT_PROBE_WAIT(recursive, InstanceKlass::cast(this_oop()), -1,wait);
return;
}
// Step 4
if (this_oop->is_initialized()) {
DTRACE_CLASSINIT_PROBE_WAIT(concurrent, InstanceKlass::cast(this_oop()), -1,wait);
return;
}
// Step 5
if (this_oop->is_in_error_state()) {
DTRACE_CLASSINIT_PROBE_WAIT(erroneous, InstanceKlass::cast(this_oop()), -1,wait);
ResourceMark rm(THREAD);
const char* desc = "Could not initialize class ";
const char* className = this_oop->external_name();
size_t msglen = strlen(desc) + strlen(className) + 1;
char* message = NEW_RESOURCE_ARRAY(char, msglen);
if (NULL == message) {
// Out of memory: can't create detailed error message
THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
} else {
jio_snprintf(message, msglen, "%s%s", desc, className);
THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
}
}
// Step 6
this_oop->set_init_state(being_initialized);
this_oop->set_init_thread(self);
}
// Step 7
// Next, if C is a class rather than an interface, initialize its super class and super
// interfaces.
if (!this_oop->is_interface()) {
Klass* super_klass = this_oop->super();
if (super_klass != NULL && super_klass->should_be_initialized()) {
super_klass->initialize(THREAD);
}
// If C implements any interfaces that declares a non-abstract, non-static method,
// the initialization of C triggers initialization of its super interfaces.
// Only need to recurse if has_default_methods which includes declaring and
// inheriting default methods
if (!HAS_PENDING_EXCEPTION && this_oop->has_default_methods()) {
this_oop->initialize_super_interfaces(this_oop, THREAD);
}
// If any exceptions, complete abruptly, throwing the same exception as above.
if (HAS_PENDING_EXCEPTION) {
Handle e(THREAD, PENDING_EXCEPTION);
CLEAR_PENDING_EXCEPTION;
{
EXCEPTION_MARK;
// Locks object, set state, and notify all waiting threads
this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
CLEAR_PENDING_EXCEPTION;
}
DTRACE_CLASSINIT_PROBE_WAIT(super__failed, InstanceKlass::cast(this_oop()), -1,wait);
THROW_OOP(e());
}
}
// Step 8
{
assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
JavaThread* jt = (JavaThread*)THREAD;
DTRACE_CLASSINIT_PROBE_WAIT(clinit, InstanceKlass::cast(this_oop()), -1,wait);
// Timer includes any side effects of class initialization (resolution,
// etc), but not recursive entry into call_class_initializer().
PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
ClassLoader::perf_class_init_selftime(),
ClassLoader::perf_classes_inited(),
jt->get_thread_stat()->perf_recursion_counts_addr(),
jt->get_thread_stat()->perf_timers_addr(),
PerfClassTraceTime::CLASS_CLINIT);
this_oop->call_class_initializer(THREAD);
}
// Step 9
if (!HAS_PENDING_EXCEPTION) {
this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
{ ResourceMark rm(THREAD);
debug_only(this_oop->vtable()->verify(tty, true);)
}
}
else {
// Step 10 and 11
Handle e(THREAD, PENDING_EXCEPTION);
CLEAR_PENDING_EXCEPTION;
// JVMTI has already reported the pending exception
// JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
{
EXCEPTION_MARK;
this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
// JVMTI has already reported the pending exception
// JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
}
DTRACE_CLASSINIT_PROBE_WAIT(error, InstanceKlass::cast(this_oop()), -1,wait);
if (e->is_a(SystemDictionary::Error_klass())) {
THROW_OOP(e());
} else {
JavaCallArguments args(e);
THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
vmSymbols::throwable_void_signature(),
&args);
}
}
DTRACE_CLASSINIT_PROBE_WAIT(end, InstanceKlass::cast(this_oop()), -1,wait);
}
好了,上面是C++ 代码,中文翻译我复合上
官方文档:
调用InstanceKlass::initialize_impl()方法对类进行初始化。这个方法的源代码位置在oops/instanceKlass.cpp。在对类进行初始化之前必须保证类已经完成连接，I在连接完成后要进行类的初始化。initialize_impl()方法的实现如下：
instanceKlass.cpp
void InstanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
// Make sure klass is linked (verified) before initialization
// A class could already be verified, since it has been reflected upon.
this_oop->link_class(CHECK);
bool wait = false;
// refer to the JVM book page 47 for description of steps
// step 1：通过ObjectLocker在初始化之前进行加锁，防止多个线程并发初始化。
{
oop init_lock = this_oop->init_lock();
ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
Thread *self = THREAD; // it's passed the current thread
// step 2：如果当前instanceKlassHandle正在被初始化，且初始化线程不是当前线程，
// 则执行ol.waitUninterruptibly(CHECK)，等待其他线程初始化完成后通知。
// If we were to use wait() instead of waitInterruptibly() then
// we might end up throwing IE from link/symbol resolution sites
// that aren't expected to throw. This would wreak havoc. See 6320309.
while(
this_oop->is_being_initialized() && // 类正在进行初始化（being_initialized状态）
!this_oop->is_reentrant_initialization(self) // 执行初始化的线程不是当前的线程
){
wait = true;
ol.waitUninterruptibly(CHECK);
}
// step 3：当前类正在被当前线程正在被初始化。例如如果X类有静态变量指向new Y类实例，Y类中又有静态变量指向new X类实例，
// 这样外部在调用X时需要初始化X类，初始化过程中又要触发Y类的初始化，而Y类初始化又再次触发X类的初始化
if (
this_oop->is_being_initialized() && // 类正在进行初始化（being_initialized状态）
this_oop->is_reentrant_initialization(self) // 执行初始化的线程的就是当前线程
){
return;
}
// step 4：类已经初始化完成（fully_initialized状态）
if (this_oop->is_initialized()) {
return;
}
// step 5：类的初始化出错（initialization_error状态），则抛出NoClassDefFoundError异常
if (this_oop->is_in_error_state()) {
ResourceMark rm(THREAD);
const char* desc = "Could not initialize class ";
const char* className = this_oop->external_name();
size_t msglen = strlen(desc) + strlen(className) + 1;
char* message = NEW_RESOURCE_ARRAY(char, msglen);
if (NULL == message) {
// Out of memory: can't create detailed error message
THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
} else {
jio_snprintf(message, msglen, "%s%s", desc, className);
THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
}
}
// step 6：设置类的初始化状态为being_initialized，设置初始化的线程为当前线程
this_oop->set_init_state(being_initialized);
this_oop->set_init_thread(self);
}
// step 7：如果当前初始化的不是接口、父类不为空并且父类未初始化，则初始化其父类
Klass* super_klass = this_oop->super();
if (
super_klass != NULL &&
!this_oop->is_interface() &&
// 也就是判断super_klass的状态是否为fully_initialized，
// 如果是，should_be_initialized()方法将返回true
super_klass->should_be_initialized()
){
super_klass->initialize(THREAD);
// ...
}
if (this_oop->has_default_methods()) {
// Step 7.5: 初始化有默认方法的接口
for (int i = 0; i < this_oop->local_interfaces()->length(); ++i) {
Klass* iface = this_oop->local_interfaces()->at(i);
InstanceKlass* ik = InstanceKlass::cast(iface);
if (ik->has_default_methods() && ik->should_be_initialized()) {
ik->initialize(THREAD);
// ...
}
}
}
// Step 8
// 执行类或接口的初始化方法<clinit>
{
this_oop->call_class_initializer(THREAD); // 调用类或接口的<clinit>方法
}
// Step 9
// 如果初始化过程没有异常，说明已经完成初始化，设置类的状态为full_initialized并通知其他线程初始化已经完成。
if (!HAS_PENDING_EXCEPTION) {
this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
}
else {
// Step 10 and 11
// 如果初始化过程发生异常，则通过set_initialization_state_and_notify()方法设置类的
// 状态为initialization_error并通知其他线程，然后抛出错误或异常
Handle e(THREAD, PENDING_EXCEPTION);
CLEAR_PENDING_EXCEPTION;
{
EXCEPTION_MARK;
this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
}
// ...
}
}
InstanceKlass类 重要的属性解析
| _init_state | 表示类的状态，为枚举类型ClassState，定义了如下常量值： - allocated（已分配内存） - loaded（从class文件读取加载到内存中） - linked（已经成功链接和校验） - being_initialized（正在初始化） - fully_initialized（已经完成初始化） - initialization_error（初始化异常） |
|---|---|
| _init_thread | 执行此类初始化的Thread指针 |
这段初始化klass步骤在JVM规范中有详细描述，假设当前类(接口)为C，它持有一个独有的初始化锁LC
同步锁LC，防止并发导致多次初始化<br /> 如果有其他线程正在初始化C，就释放LC并阻塞当前线程直到那个线程完成初始化<br /> 如果是执行初始化的是当前线程，则表明是递归请求，释放LC并正常完成初始化<br /> 如果C已经被初始化了，则释放LC并正常完成初始化<br /> 如果C的对象处于一个错误状态，则释放LC并抛出NoClassDefFoundError异常<br /> 记录C正在被当前线程初始化并释放LC，初始化类中所有final static字段<br /> 如果C是一个类，初始化其父类和接口<br /> 判断C是否打开断言<br /> 执行类(接口)的初始化方法<br /> 标记C已经完全初始化，并唤醒所有的等待线程<br /> 如果初始化失败，则抛出异常，并将C标记为错误，同时唤醒所有的等待线程<br />
image.png
### ### 整个JVM对象分配的整体流程大致如下，
从 Class 文件到加载到内存中的类，到类卸载出内存位置 ### 
IDEA Debug 的过程
注意 和
image.png
AA 和BB 的clinit 结束 开始init
AA 被new 出来
线程一已经完成工作,开始线程二工作
线程的dump 结果
Full thread dump
"Thread-1@656" prio=5 tid=0xf nid=NA runnable
java.lang.Thread.State: RUNNABLE
at test.InitDeadLock.lambda$main$1(InitDeadLock.java:11)
at test.InitDeadLock$$Lambda$2.295530567.run(Unknown Source:-1)
at java.lang.Thread.run(Thread.java:748)
"Finalizer@665" daemon prio=8 tid=0x3 nid=NA waiting
java.lang.Thread.State: WAITING
at java.lang.Object.wait(Object.java:-1)
at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:144)
at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:165)
at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:216)
"Reference Handler@666" daemon prio=10 tid=0x2 nid=NA waiting
java.lang.Thread.State: WAITING
at java.lang.Object.wait(Object.java:-1)
at java.lang.Object.wait(Object.java:502)
at java.lang.ref.Reference.tryHandlePending(Reference.java:191)
at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:153)
"DestroyJavaVM@657" prio=5 tid=0x10 nid=NA runnable
java.lang.Thread.State: RUNNABLE
"Attach Listener@663" daemon prio=5 tid=0x5 nid=NA runnable
java.lang.Thread.State: RUNNABLE
"Signal Dispatcher@664" daemon prio=9 tid=0x4 nid=NA runnable
java.lang.Thread.State: RUNNABLE
**解释 深入理解java 虚拟机 **书中279页