8228485: JVM crashes when bootstrap method for condy triggers loading of class whose static initializer throws exception
Summary: Add case for JVM_CONSTANT_Dynamic in error_message function.
Reviewed-by: dholmes, shade
/*
* 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.
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*/
#include "precompiled.hpp"
#include "jvm.h"
#include "aot/aotLoader.hpp"
#include "classfile/classFileParser.hpp"
#include "classfile/classFileStream.hpp"
#include "classfile/classLoader.hpp"
#include "classfile/classLoaderData.inline.hpp"
#include "classfile/javaClasses.hpp"
#include "classfile/moduleEntry.hpp"
#include "classfile/symbolTable.hpp"
#include "classfile/systemDictionary.hpp"
#include "classfile/systemDictionaryShared.hpp"
#include "classfile/verifier.hpp"
#include "classfile/vmSymbols.hpp"
#include "code/dependencyContext.hpp"
#include "compiler/compileBroker.hpp"
#include "gc/shared/collectedHeap.inline.hpp"
#include "interpreter/oopMapCache.hpp"
#include "interpreter/rewriter.hpp"
#include "jvmtifiles/jvmti.h"
#include "logging/log.hpp"
#include "logging/logMessage.hpp"
#include "logging/logStream.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/heapInspection.hpp"
#include "memory/iterator.inline.hpp"
#include "memory/metadataFactory.hpp"
#include "memory/metaspaceClosure.hpp"
#include "memory/metaspaceShared.hpp"
#include "memory/oopFactory.hpp"
#include "memory/resourceArea.hpp"
#include "memory/universe.hpp"
#include "oops/fieldStreams.hpp"
#include "oops/constantPool.hpp"
#include "oops/instanceClassLoaderKlass.hpp"
#include "oops/instanceKlass.inline.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/jvmtiRedefineClasses.hpp"
#include "prims/jvmtiThreadState.hpp"
#include "prims/methodComparator.hpp"
#include "runtime/atomic.hpp"
#include "runtime/fieldDescriptor.inline.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/orderAccess.hpp"
#include "runtime/thread.inline.hpp"
#include "services/classLoadingService.hpp"
#include "services/threadService.hpp"
#include "utilities/dtrace.hpp"
#include "utilities/events.hpp"
#include "utilities/macros.hpp"
#include "utilities/stringUtils.hpp"
#ifdef COMPILER1
#include "c1/c1_Compiler.hpp"
#endif
#if INCLUDE_JFR
#include "jfr/jfrEvents.hpp"
#endif
#ifdef DTRACE_ENABLED
#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, thread_type) \
{ \
char* data = NULL; \
int len = 0; \
Symbol* clss_name = name(); \
if (clss_name != NULL) { \
data = (char*)clss_name->bytes(); \
len = clss_name->utf8_length(); \
} \
HOTSPOT_CLASS_INITIALIZATION_##type( \
data, len, (void*)class_loader(), thread_type); \
}
#define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
{ \
char* data = NULL; \
int len = 0; \
Symbol* clss_name = name(); \
if (clss_name != NULL) { \
data = (char*)clss_name->bytes(); \
len = clss_name->utf8_length(); \
} \
HOTSPOT_CLASS_INITIALIZATION_##type( \
data, len, (void*)class_loader(), thread_type, wait); \
}
#else // ndef DTRACE_ENABLED
#define DTRACE_CLASSINIT_PROBE(type, thread_type)
#define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
#endif // ndef DTRACE_ENABLED
static inline bool is_class_loader(const Symbol* class_name,
const ClassFileParser& parser) {
assert(class_name != NULL, "invariant");
if (class_name == vmSymbols::java_lang_ClassLoader()) {
return true;
}
if (SystemDictionary::ClassLoader_klass_loaded()) {
const Klass* const super_klass = parser.super_klass();
if (super_klass != NULL) {
if (super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass())) {
return true;
}
}
}
return false;
}
// called to verify that k is a member of this nest
bool InstanceKlass::has_nest_member(InstanceKlass* k, TRAPS) const {
if (_nest_members == NULL || _nest_members == Universe::the_empty_short_array()) {
if (log_is_enabled(Trace, class, nestmates)) {
ResourceMark rm(THREAD);
log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
k->external_name(), this->external_name());
}
return false;
}
if (log_is_enabled(Trace, class, nestmates)) {
ResourceMark rm(THREAD);
log_trace(class, nestmates)("Checking nest membership of %s in %s",
k->external_name(), this->external_name());
}
// Check for a resolved cp entry , else fall back to a name check.
// We don't want to resolve any class other than the one being checked.
for (int i = 0; i < _nest_members->length(); i++) {
int cp_index = _nest_members->at(i);
if (_constants->tag_at(cp_index).is_klass()) {
Klass* k2 = _constants->klass_at(cp_index, CHECK_false);
if (k2 == k) {
log_trace(class, nestmates)("- class is listed at nest_members[%d] => cp[%d]", i, cp_index);
return true;
}
}
else {
Symbol* name = _constants->klass_name_at(cp_index);
if (name == k->name()) {
log_trace(class, nestmates)("- Found it at nest_members[%d] => cp[%d]", i, cp_index);
// Names match so check actual klass - this may trigger class loading if
// it doesn't match (though that should be impossible). But to be safe we
// have to check for a compiler thread executing here.
if (!THREAD->can_call_java() && !_constants->tag_at(cp_index).is_klass()) {
log_trace(class, nestmates)("- validation required resolution in an unsuitable thread");
return false;
}
Klass* k2 = _constants->klass_at(cp_index, CHECK_false);
if (k2 == k) {
log_trace(class, nestmates)("- class is listed as a nest member");
return true;
}
else {
// same name but different klass!
log_trace(class, nestmates)(" - klass comparison failed!");
// can't have two names the same, so we're done
return false;
}
}
}
}
log_trace(class, nestmates)("- class is NOT a nest member!");
return false;
}
// Return nest-host class, resolving, validating and saving it if needed.
// In cases where this is called from a thread that can not do classloading
// (such as a native JIT thread) then we simply return NULL, which in turn
// causes the access check to return false. Such code will retry the access
// from a more suitable environment later.
InstanceKlass* InstanceKlass::nest_host(Symbol* validationException, TRAPS) {
InstanceKlass* nest_host_k = _nest_host;
if (nest_host_k == NULL) {
// need to resolve and save our nest-host class. This could be attempted
// concurrently but as the result is idempotent and we don't use the class
// then we do not need any synchronization beyond what is implicitly used
// during class loading.
if (_nest_host_index != 0) { // we have a real nest_host
// Before trying to resolve check if we're in a suitable context
if (!THREAD->can_call_java() && !_constants->tag_at(_nest_host_index).is_klass()) {
if (log_is_enabled(Trace, class, nestmates)) {
ResourceMark rm(THREAD);
log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
this->external_name());
}
return NULL;
}
if (log_is_enabled(Trace, class, nestmates)) {
ResourceMark rm(THREAD);
log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
this->external_name(),
_constants->klass_name_at(_nest_host_index)->as_C_string());
}
Klass* k = _constants->klass_at(_nest_host_index, THREAD);
if (HAS_PENDING_EXCEPTION) {
Handle exc_h = Handle(THREAD, PENDING_EXCEPTION);
if (exc_h->is_a(SystemDictionary::NoClassDefFoundError_klass())) {
// throw a new CDNFE with the original as its cause, and a clear msg
ResourceMark rm(THREAD);
char buf[200];
CLEAR_PENDING_EXCEPTION;
jio_snprintf(buf, sizeof(buf),
"Unable to load nest-host class (%s) of %s",
_constants->klass_name_at(_nest_host_index)->as_C_string(),
this->external_name());
log_trace(class, nestmates)("%s - NoClassDefFoundError", buf);
THROW_MSG_CAUSE_NULL(vmSymbols::java_lang_NoClassDefFoundError(), buf, exc_h);
}
// All other exceptions pass through (OOME, StackOverflowError, LinkageErrors etc).
return NULL;
}
// A valid nest-host is an instance class in the current package that lists this
// class as a nest member. If any of these conditions are not met we post the
// requested exception type (if any) and return NULL
const char* error = NULL;
// JVMS 5.4.4 indicates package check comes first
if (is_same_class_package(k)) {
// Now check actual membership. We can't be a member if our "host" is
// not an instance class.
if (k->is_instance_klass()) {
nest_host_k = InstanceKlass::cast(k);
bool is_member = nest_host_k->has_nest_member(this, CHECK_NULL);
if (is_member) {
// save resolved nest-host value
_nest_host = nest_host_k;
if (log_is_enabled(Trace, class, nestmates)) {
ResourceMark rm(THREAD);
log_trace(class, nestmates)("Resolved nest-host of %s to %s",
this->external_name(), k->external_name());
}
return nest_host_k;
}
}
error = "current type is not listed as a nest member";
} else {
error = "types are in different packages";
}
if (log_is_enabled(Trace, class, nestmates)) {
ResourceMark rm(THREAD);
log_trace(class, nestmates)
("Type %s (loader: %s) is not a nest member of "
"resolved type %s (loader: %s): %s",
this->external_name(),
this->class_loader_data()->loader_name_and_id(),
k->external_name(),
k->class_loader_data()->loader_name_and_id(),
error);
}
if (validationException != NULL && THREAD->can_call_java()) {
ResourceMark rm(THREAD);
Exceptions::fthrow(THREAD_AND_LOCATION,
validationException,
"Type %s (loader: %s) is not a nest member of %s (loader: %s): %s",
this->external_name(),
this->class_loader_data()->loader_name_and_id(),
k->external_name(),
k->class_loader_data()->loader_name_and_id(),
error
);
}
return NULL;
} else {
if (log_is_enabled(Trace, class, nestmates)) {
ResourceMark rm(THREAD);
log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
this->external_name());
}
// save resolved nest-host value
return (_nest_host = this);
}
}
return nest_host_k;
}
// check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
// or we are k's nest_host - all of which is covered by comparing the two
// resolved_nest_hosts
bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
assert(this != k, "this should be handled by higher-level code");
// Per JVMS 5.4.4 we first resolve and validate the current class, then
// the target class k. Resolution exceptions will be passed on by upper
// layers. IncompatibleClassChangeErrors from membership validation failures
// will also be passed through.
Symbol* icce = vmSymbols::java_lang_IncompatibleClassChangeError();
InstanceKlass* cur_host = nest_host(icce, CHECK_false);
if (cur_host == NULL) {
return false;
}
Klass* k_nest_host = k->nest_host(icce, CHECK_false);
if (k_nest_host == NULL) {
return false;
}
bool access = (cur_host == k_nest_host);
if (log_is_enabled(Trace, class, nestmates)) {
ResourceMark rm(THREAD);
log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
this->external_name(),
access ? "" : "NOT ",
k->external_name());
}
return access;
}
InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
const int size = InstanceKlass::size(parser.vtable_size(),
parser.itable_size(),
nonstatic_oop_map_size(parser.total_oop_map_count()),
parser.is_interface(),
parser.is_unsafe_anonymous(),
should_store_fingerprint(parser.is_unsafe_anonymous()));
const Symbol* const class_name = parser.class_name();
assert(class_name != NULL, "invariant");
ClassLoaderData* loader_data = parser.loader_data();
assert(loader_data != NULL, "invariant");
InstanceKlass* ik;
// Allocation
if (REF_NONE == parser.reference_type()) {
if (class_name == vmSymbols::java_lang_Class()) {
// mirror
ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
}
else if (is_class_loader(class_name, parser)) {
// class loader
ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
} else {
// normal
ik = new (loader_data, size, THREAD) InstanceKlass(parser, InstanceKlass::_misc_kind_other);
}
} else {
// reference
ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
}
// Check for pending exception before adding to the loader data and incrementing
// class count. Can get OOM here.
if (HAS_PENDING_EXCEPTION) {
return NULL;
}
return ik;
}
// copy method ordering from resource area to Metaspace
void InstanceKlass::copy_method_ordering(const 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(const ClassFileParser& parser, unsigned kind, KlassID id) :
Klass(id),
_nest_members(NULL),
_nest_host_index(0),
_nest_host(NULL),
_static_field_size(parser.static_field_size()),
_nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
_itable_len(parser.itable_size()),
_init_thread(NULL),
_init_state(allocated),
_reference_type(parser.reference_type())
{
set_vtable_length(parser.vtable_size());
set_kind(kind);
set_access_flags(parser.access_flags());
set_is_unsafe_anonymous(parser.is_unsafe_anonymous());
set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
false));
assert(NULL == _methods, "underlying memory not zeroed?");
assert(is_instance_klass(), "is layout incorrect?");
assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
if (DumpSharedSpaces || DynamicDumpSharedSpaces) {
SystemDictionaryShared::init_dumptime_info(this);
}
}
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,
const Klass* super_klass,
Array<InstanceKlass*>* local_interfaces,
Array<InstanceKlass*>* transitive_interfaces) {
// Only deallocate transitive interfaces if not empty, same as super class
// or same as local interfaces. See code in parseClassFile.
Array<InstanceKlass*>* ti = transitive_interfaces;
if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
// check that the interfaces don't come from super class
Array<InstanceKlass*>* sti = (super_klass == NULL) ? NULL :
InstanceKlass::cast(super_klass)->transitive_interfaces();
if (ti != sti && ti != NULL && !ti->is_shared()) {
MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
}
}
// local interfaces can be empty
if (local_interfaces != Universe::the_empty_instance_klass_array() &&
local_interfaces != NULL && !local_interfaces->is_shared()) {
MetadataFactory::free_array<InstanceKlass*>(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);
}
// Also remove mirror from handles
loader_data->remove_handle(_java_mirror);
// 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() &&
// see comments in compute_secondary_supers about the following cast
(address)(secondary_supers()) != (address)(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);
if (nest_members() != NULL &&
nest_members() != Universe::the_empty_short_array() &&
!nest_members()->is_shared()) {
MetadataFactory::free_array<jushort>(loader_data, nest_members());
}
set_nest_members(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);
if (DumpSharedSpaces || DynamicDumpSharedSpaces) {
SystemDictionaryShared::remove_dumptime_info(this);
}
}
bool InstanceKlass::should_be_initialized() const {
return !is_initialized();
}
klassItable InstanceKlass::itable() const {
return klassItable(const_cast<InstanceKlass*>(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_klass = super();
if (super_klass == NULL) return;
// abort if the super class should be initialized
if (!InstanceKlass::cast(super_klass)->is_initialized()) return;
// call body to expose the this pointer
eager_initialize_impl();
}
}
// 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() {
EXCEPTION_MARK;
HandleMark hm(THREAD);
Handle h_init_lock(THREAD, init_lock());
ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
// abort if someone beat us to the initialization
if (!is_not_initialized()) return; // note: not equivalent to is_initialized()
ClassState old_state = init_state();
link_class_impl(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 != _init_state)
set_init_state(old_state);
} else {
// linking successfull, mark class as initialized
set_init_state(fully_initialized);
fence_and_clear_init_lock();
// trace
if (log_is_enabled(Info, class, init)) {
ResourceMark rm(THREAD);
log_info(class, init)("[Initialized %s without side effects]", 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()) {
initialize_impl(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(TRAPS) {
// 1) Verify the bytecodes
return Verifier::verify(this, should_verify_class(), THREAD);
}
void InstanceKlass::link_class(TRAPS) {
assert(is_loaded(), "must be loaded");
if (!is_linked()) {
link_class_impl(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()) {
link_class_impl(CHECK_false);
}
return is_linked();
}
bool InstanceKlass::link_class_impl(TRAPS) {
if (DumpSharedSpaces && is_in_error_state()) {
// This is for CDS dumping phase only -- we use the in_error_state to indicate that
// the class has failed verification. Throwing the NoClassDefFoundError here is just
// a convenient way to stop repeat attempts to verify the same (bad) class.
//
// Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
// if we are executing Java code. This is not a problem for CDS dumping phase since
// it doesn't execute any Java code.
ResourceMark rm(THREAD);
Exceptions::fthrow(THREAD_AND_LOCATION,
vmSymbols::java_lang_NoClassDefFoundError(),
"Class %s, or one of its supertypes, failed class initialization",
external_name());
return false;
}
// return if already verified
if (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
Klass* super_klass = super();
if (super_klass != NULL) {
if (super_klass->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",
external_name(),
super_klass->external_name()
);
return false;
}
InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
ik_super->link_class_impl(CHECK_false);
}
// link all interfaces implemented by this class before linking this class
Array<InstanceKlass*>* interfaces = local_interfaces();
int num_interfaces = interfaces->length();
for (int index = 0; index < num_interfaces; index++) {
InstanceKlass* interk = interfaces->at(index);
interk->link_class_impl(CHECK_false);
}
// in case the class is linked in the process of linking its superclasses
if (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
{
HandleMark hm(THREAD);
Handle h_init_lock(THREAD, init_lock());
ObjectLocker ol(h_init_lock, THREAD, h_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 (!is_linked()) {
if (!is_rewritten()) {
{
bool verify_ok = verify_code(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 (is_linked()) {
return true;
}
// also sets rewritten
rewrite_class(CHECK_false);
} else if (is_shared()) {
SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
}
// relocate jsrs and link methods after they are all rewritten
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 = class_loader_data();
if (!(is_shared() &&
loader_data->is_the_null_class_loader_data())) {
vtable().initialize_vtable(true, CHECK_false);
itable().initialize_itable(true, CHECK_false);
}
#ifdef ASSERT
else {
vtable().verify(tty, true);
// In case itable verification is ever added.
// itable().verify(tty, true);
}
#endif
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);
}
}
}
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");
if (is_rewritten()) {
assert(is_shared(), "rewriting an unshared class?");
return;
}
Rewriter::rewrite(this, CHECK);
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);
}
}
// Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
void InstanceKlass::initialize_super_interfaces(TRAPS) {
assert (has_nonstatic_concrete_methods(), "caller should have checked this");
for (int i = 0; i < local_interfaces()->length(); ++i) {
InstanceKlass* ik = local_interfaces()->at(i);
// Initialization is depth first search ie. we start with top of the inheritance tree
// has_nonstatic_concrete_methods drives searching superinterfaces since it
// means has_nonstatic_concrete_methods in its superinterface hierarchy
if (ik->has_nonstatic_concrete_methods()) {
ik->initialize_super_interfaces(CHECK);
}
// Only initialize() interfaces that "declare" concrete methods.
if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
ik->initialize(CHECK);
}
}
}
void InstanceKlass::initialize_impl(TRAPS) {
HandleMark hm(THREAD);
// Make sure klass is linked (verified) before initialization
// A class could already be verified, since it has been reflected upon.
link_class(CHECK);
DTRACE_CLASSINIT_PROBE(required, -1);
bool wait = false;
assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
JavaThread* jt = (JavaThread*)THREAD;
// refer to the JVM book page 47 for description of steps
// Step 1
{
Handle h_init_lock(THREAD, init_lock());
ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
// 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 (is_being_initialized() && !is_reentrant_initialization(jt)) {
wait = true;
jt->set_class_to_be_initialized(this);
ol.waitUninterruptibly(jt);
jt->set_class_to_be_initialized(NULL);
}
// Step 3
if (is_being_initialized() && is_reentrant_initialization(jt)) {
DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
return;
}
// Step 4
if (is_initialized()) {
DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
return;
}
// Step 5
if (is_in_error_state()) {
DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
ResourceMark rm(THREAD);
const char* desc = "Could not initialize class ";
const char* className = 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
set_init_state(being_initialized);
set_init_thread(jt);
}
// Step 7
// Next, if C is a class rather than an interface, initialize it's super class and super
// interfaces.
if (!is_interface()) {
Klass* super_klass = super();
if (super_klass != NULL && super_klass->should_be_initialized()) {
super_klass->initialize(THREAD);
}
// If C implements any interface that declares a non-static, concrete method,
// the initialization of C triggers initialization of its super interfaces.
// Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
// having a superinterface that declares, non-static, concrete methods
if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
initialize_super_interfaces(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
set_initialization_state_and_notify(initialization_error, THREAD);
CLEAR_PENDING_EXCEPTION;
}
DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
THROW_OOP(e());
}
}
// Look for aot compiled methods for this klass, including class initializer.
AOTLoader::load_for_klass(this, THREAD);
// Step 8
{
DTRACE_CLASSINIT_PROBE_WAIT(clinit, -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);
call_class_initializer(THREAD);
}
// Step 9
if (!HAS_PENDING_EXCEPTION) {
set_initialization_state_and_notify(fully_initialized, CHECK);
{
debug_only(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(jt);
{
EXCEPTION_MARK;
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(jt);
}
DTRACE_CLASSINIT_PROBE_WAIT(error, -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, -1, wait);
}
void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
Handle h_init_lock(THREAD, init_lock());
if (h_init_lock() != NULL) {
ObjectLocker ol(h_init_lock, THREAD);
set_init_thread(NULL); // reset _init_thread before changing _init_state
set_init_state(state);
fence_and_clear_init_lock();
ol.notify_all(CHECK);
} else {
assert(h_init_lock() != NULL, "The initialization state should never be set twice");
set_init_thread(NULL); // reset _init_thread before changing _init_state
set_init_state(state);
}
}
Klass* InstanceKlass::implementor() const {
Klass* volatile* k = adr_implementor();
if (k == NULL) {
return NULL;
} else {
// This load races with inserts, and therefore needs acquire.
Klass* kls = OrderAccess::load_acquire(k);
if (kls != NULL && !kls->is_loader_alive()) {
return NULL; // don't return unloaded class
} else {
return kls;
}
}
}
void InstanceKlass::set_implementor(Klass* k) {
assert_lock_strong(Compile_lock);
assert(is_interface(), "not interface");
Klass* volatile* addr = adr_implementor();
assert(addr != NULL, "null addr");
if (addr != NULL) {
OrderAccess::release_store(addr, k);
}
}
int InstanceKlass::nof_implementors() const {
Klass* k = implementor();
if (k == NULL) {
return 0;
} else if (k != this) {
return 1;
} else {
return 2;
}
}
// 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_lock_strong(Compile_lock);
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 = 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
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);
}
}
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,
Array<InstanceKlass*>* transitive_interfaces) {
// The secondaries are the implemented interfaces.
Array<InstanceKlass*>* interfaces = 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, so
// let's use it instead of making a copy.
// Redefine classes has to be careful not to delete this!
// We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
// (but it's safe to do here because we won't write into _secondary_supers from this point on).
set_secondary_supers((Array<Klass*>*)(address)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::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) {
check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
int size = objArrayOopDesc::object_size(length);
Klass* ak = array_klass(n, CHECK_NULL);
objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
/* do_zero */ true, 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", p2i(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.
instanceOop i;
i = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
if (has_finalizer_flag && !RegisterFinalizersAtInit) {
i = register_finalizer(i, CHECK_NULL);
}
return i;
}
instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
return instanceHandle(THREAD, allocate_instance(THREAD));
}
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) {
// Need load-acquire for lock-free read
if (array_klasses_acquire() == NULL) {
if (or_null) return NULL;
ResourceMark rm;
JavaThread *jt = (JavaThread *)THREAD;
{
// Atomic creation of array_klasses
MutexLocker ma(MultiArray_lock, THREAD);
// Check if update has already taken place
if (array_klasses() == NULL) {
Klass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
// use 'release' to pair with lock-free load
release_set_array_klasses(k);
}
}
}
// _this will always be set at this point
ObjArrayKlass* oak = (ObjArrayKlass*)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);
}
static int call_class_initializer_counter = 0; // for debugging
Method* InstanceKlass::class_initializer() const {
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(TRAPS) {
if (ReplayCompiles &&
(ReplaySuppressInitializers == 1 ||
(ReplaySuppressInitializers >= 2 && class_loader() != NULL))) {
// Hide the existence of the initializer for the purpose of replaying the compile
return;
}
methodHandle h_method(THREAD, class_initializer());
assert(!is_initialized(), "we cannot initialize twice");
LogTarget(Info, class, init) lt;
if (lt.is_enabled()) {
ResourceMark rm;
LogStream ls(lt);
ls.print("%d Initializing ", call_class_initializer_counter++);
name()->print_value_on(&ls);
ls.print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this));
}
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(const methodHandle& method, int bci,
InterpreterOopMap* entry_for) {
// Lazily create the _oop_map_cache at first request
// Lock-free access requires load_acquire.
OopMapCache* oop_map_cache = OrderAccess::load_acquire(&_oop_map_cache);
if (oop_map_cache == NULL) {
MutexLocker x(OopMapCacheAlloc_lock);
// Check if _oop_map_cache was allocated while we were waiting for this lock
if ((oop_map_cache = _oop_map_cache) == NULL) {
oop_map_cache = new OopMapCache();
// Ensure _oop_map_cache is stable, since it is examined without a lock
OrderAccess::release_store(&_oop_map_cache, oop_map_cache);
}
}
// _oop_map_cache is constant after init; lookup below does its 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)) {
// Methods aren't stable until they are loaded. This can be read outside
// a lock through the ClassLoaderData for profiling
if (!is_loaded()) {
return;
}
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) {
for (JavaFieldStream fs(this); !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);
}
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(const Array<Method*>* methods,
const Symbol* name,
const Symbol* signature) {
const int len = methods->length();
for (int index = 0; index < len; index++) {
const Method* const 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(const Array<Method*>* methods, const 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(const Symbol* name,
const Symbol* signature) const {
return find_method_impl(name, signature, find_overpass, find_static, find_private);
}
Method* InstanceKlass::find_method_impl(const Symbol* name,
const 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(const Array<Method*>* methods,
const Symbol* name,
const Symbol* signature,
PrivateLookupMode private_mode) {
Method* const meth = InstanceKlass::find_method_impl(methods,
name,
signature,
find_overpass,
skip_static,
private_mode);
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(const Symbol* name,
const Symbol* signature,
PrivateLookupMode private_mode) const {
return InstanceKlass::find_instance_method(methods(), name, signature, 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(const Symbol* name,
const 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(const Array<Method*>* methods,
const Symbol* name,
const 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);
}
Method* InstanceKlass::find_method(const Array<Method*>* methods,
const Symbol* name,
const Symbol* signature) {
return InstanceKlass::find_method_impl(methods,
name,
signature,
find_overpass,
find_static,
find_private);
}
Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
const Symbol* name,
const 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;
}
// true if method matches signature and conforms to skipping_X conditions.
static bool method_matches(const Method* m,
const 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(const Array<Method*>* methods,
const Symbol* name,
const Symbol* signature,
OverpassLookupMode overpass_mode,
StaticLookupMode static_mode,
PrivateLookupMode private_mode) {
const bool skipping_overpass = (overpass_mode == skip_overpass);
const bool skipping_static = (static_mode == skip_static);
const bool skipping_private = (private_mode == skip_private);
const int hit = binary_search(methods, name);
if (hit != -1) {
const Method* const 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) {
const Method* const 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) {
const Method* const 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
const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
linear_search(methods, name, signature);
assert(-1 == index, "binary search should have found entry %d", index);
#endif
}
return -1;
}
int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
return find_method_by_name(methods(), name, end);
}
int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
const 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,
// and possibly skipping private methods.
Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
const Symbol* signature,
OverpassLookupMode overpass_mode,
PrivateLookupMode private_mode) const {
OverpassLookupMode overpass_local_mode = overpass_mode;
const Klass* klass = this;
while (klass != NULL) {
Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
signature,
overpass_local_mode,
find_static,
private_mode);
if (method != NULL) {
return method;
}
klass = 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 Klass* klass = this;
while (klass != NULL) {
if (InstanceKlass::cast(klass)->has_been_redefined()) {
return true;
}
klass = 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<InstanceKlass*>* all_ifs = transitive_interfaces();
int num_ifs = all_ifs->length();
InstanceKlass *ik = NULL;
for (int i = 0; i < num_ifs; i++) {
ik = 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(int offset) {
MutexLocker ml(JfieldIdCreation_lock);
// Retry lookup after we got the lock
JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
if (probe == NULL) {
// Slow case, allocate new static field identifier
probe = new JNIid(this, offset, jni_ids());
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(offset);
}
return probe;
}
u2 InstanceKlass::enclosing_method_data(int offset) const {
const Array<jushort>* const inner_class_list = inner_classes();
if (inner_class_list == NULL) {
return 0;
}
const int length = inner_class_list->length();
if (length % inner_class_next_offset == 0) {
return 0;
}
const 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(const methodHandle& method_h) {
size_t idnum = (size_t)method_h->method_idnum();
jmethodID* jmeths = 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() 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 (!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)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 = method_with_idnum((int)idnum);
assert(current_method != NULL, "old and but not obsolete, so should exist");
new_id = Method::make_jmethod_id(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(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(idnum, new_id, new_jmeths,
&to_dealloc_id, &to_dealloc_jmeths);
} else {
MutexLocker ml(JmethodIdCreation_lock);
id = get_jmethod_id_fetch_or_update(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(class_loader_data(), to_dealloc_id);
}
}
return id;
}
// Figure out how many jmethodIDs haven't been allocated, and make
// sure space for them is pre-allocated. This makes getting all
// method ids much, much faster with classes with more than 8
// methods, and has a *substantial* effect on performance with jvmti
// code that loads all jmethodIDs for all classes.
void InstanceKlass::ensure_space_for_methodids(int start_offset) {
int new_jmeths = 0;
int length = methods()->length();
for (int index = start_offset; index < length; index++) {
Method* m = methods()->at(index);
jmethodID id = m->find_jmethod_id_or_null();
if (id == NULL) {
new_jmeths++;
}
}
if (new_jmeths != 0) {
Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
}
}
// 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(
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 = 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
}
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(&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;
}
inline DependencyContext InstanceKlass::dependencies() {
DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
return dep_context;
}
int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
return dependencies().mark_dependent_nmethods(changes);
}
void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
dependencies().add_dependent_nmethod(nm);
}
void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
dependencies().remove_dependent_nmethod(nm);
}
void InstanceKlass::clean_dependency_context() {
dependencies().clean_unloading_dependents();
}
#ifndef PRODUCT
void InstanceKlass::print_dependent_nmethods(bool verbose) {
dependencies().print_dependent_nmethods(verbose);
}
bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
return dependencies().is_dependent_nmethod(nm);
}
#endif //PRODUCT
void InstanceKlass::clean_weak_instanceklass_links() {
clean_implementors_list();
clean_method_data();
}
void InstanceKlass::clean_implementors_list() {
assert(is_loader_alive(), "this klass should be live");
if (is_interface()) {
assert (ClassUnloading, "only called for ClassUnloading");
for (;;) {
// Use load_acquire due to competing with inserts
Klass* impl = OrderAccess::load_acquire(adr_implementor());
if (impl != NULL && !impl->is_loader_alive()) {
// NULL this field, might be an unloaded klass or NULL
Klass* volatile* klass = adr_implementor();
if (Atomic::cmpxchg((Klass*)NULL, klass, impl) == impl) {
// Successfully unlinking implementor.
if (log_is_enabled(Trace, class, unload)) {
ResourceMark rm;
log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
}
return;
}
} else {
return;
}
}
}
}
void InstanceKlass::clean_method_data() {
for (int m = 0; m < methods()->length(); m++) {
MethodData* mdo = methods()->at(m)->method_data();
if (mdo != NULL) {
MutexLocker ml(SafepointSynchronize::is_at_safepoint() ? NULL : mdo->extra_data_lock());
mdo->clean_method_data(/*always_clean*/false);
}
}
}
bool InstanceKlass::supers_have_passed_fingerprint_checks() {
if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) {
ResourceMark rm;
log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name());
return false;
}
Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
if (local_interfaces != NULL) {
int length = local_interfaces->length();
for (int i = 0; i < length; i++) {
InstanceKlass* intf = local_interfaces->at(i);
if (!intf->has_passed_fingerprint_check()) {
ResourceMark rm;
log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name());
return false;
}
}
}
return true;
}
bool InstanceKlass::should_store_fingerprint(bool is_unsafe_anonymous) {
#if INCLUDE_AOT
// We store the fingerprint into the InstanceKlass only in the following 2 cases:
if (CalculateClassFingerprint) {
// (1) We are running AOT to generate a shared library.
return true;
}
if (DumpSharedSpaces || DynamicDumpSharedSpaces) {
// (2) We are running -Xshare:dump or -XX:ArchiveClassesAtExit to create a shared archive
return true;
}
if (UseAOT && is_unsafe_anonymous) {
// (3) We are using AOT code from a shared library and see an unsafe anonymous class
return true;
}
#endif
// In all other cases we might set the _misc_has_passed_fingerprint_check bit,
// but do not store the 64-bit fingerprint to save space.
return false;
}
bool InstanceKlass::has_stored_fingerprint() const {
#if INCLUDE_AOT
return should_store_fingerprint() || is_shared();
#else
return false;
#endif
}
uint64_t InstanceKlass::get_stored_fingerprint() const {
address adr = adr_fingerprint();
if (adr != NULL) {
return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned
}
return 0;
}
void InstanceKlass::store_fingerprint(uint64_t fingerprint) {
address adr = adr_fingerprint();
if (adr != NULL) {
Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned
ResourceMark rm;
log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name());
}
}
void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
Klass::metaspace_pointers_do(it);
if (log_is_enabled(Trace, cds)) {
ResourceMark rm;
log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
}
it->push(&_annotations);
it->push((Klass**)&_array_klasses);
it->push(&_constants);
it->push(&_inner_classes);
it->push(&_array_name);
#if INCLUDE_JVMTI
it->push(&_previous_versions);
#endif
it->push(&_methods);
it->push(&_default_methods);
it->push(&_local_interfaces);
it->push(&_transitive_interfaces);
it->push(&_method_ordering);
it->push(&_default_vtable_indices);
it->push(&_fields);
if (itable_length() > 0) {
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 i = 0; i < nof_interfaces; i ++, ioe ++) {
if (ioe->interface_klass() != NULL) {
it->push(ioe->interface_klass_addr());
itableMethodEntry* ime = ioe->first_method_entry(this);
int n = klassItable::method_count_for_interface(ioe->interface_klass());
for (int index = 0; index < n; index ++) {
it->push(ime[index].method_addr());
}
}
}
}
it->push(&_nest_members);
}
void InstanceKlass::remove_unshareable_info() {
Klass::remove_unshareable_info();
if (is_in_error_state()) {
// Classes are attempted to link during dumping and may fail,
// but these classes are still in the dictionary and class list in CLD.
// Check in_error state first because in_error is > linked state, so
// is_linked() is true.
// If there's a linking error, there is nothing else to remove.
return;
}
// Reset to the 'allocated' state to prevent any premature accessing to
// a shared class at runtime while the class is still being loaded and
// restored. A class' init_state is set to 'loaded' at runtime when it's
// being added to class hierarchy (see SystemDictionary:::add_to_hierarchy()).
_init_state = allocated;
{
MutexLocker ml(Compile_lock);
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.
if (array_klasses() != NULL) {
array_klasses()->remove_unshareable_info();
}
// These are not allocated from metaspace. They are safe to set to NULL.
_source_debug_extension = NULL;
_dep_context = NULL;
_osr_nmethods_head = NULL;
#if INCLUDE_JVMTI
_breakpoints = NULL;
_previous_versions = NULL;
_cached_class_file = NULL;
#endif
_init_thread = NULL;
_methods_jmethod_ids = NULL;
_jni_ids = NULL;
_oop_map_cache = NULL;
// clear _nest_host to ensure re-load at runtime
_nest_host = NULL;
}
void InstanceKlass::remove_java_mirror() {
Klass::remove_java_mirror();
// do array classes also.
if (array_klasses() != NULL) {
array_klasses()->remove_java_mirror();
}
}
void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
// SystemDictionary::add_to_hierarchy() sets the init_state to loaded
// before the InstanceKlass is added to the SystemDictionary. Make
// sure the current state is <loaded.
assert(!is_loaded(), "invalid init state");
set_package(loader_data, CHECK);
Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
Array<Method*>* methods = this->methods();
int num_methods = methods->length();
for (int index = 0; index < num_methods; ++index) {
methods->at(index)->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.
vtable().initialize_vtable(false, CHECK);
itable().initialize_itable(false, CHECK);
}
// restore constant pool resolved references
constants()->restore_unshareable_info(CHECK);
if (array_klasses() != NULL) {
// Array classes have null protection domain.
// --> see ArrayKlass::complete_create_array_klass()
array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), 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<InstanceKlass*>* interfaces = transitive_interfaces();
for (int i = 0; i < interfaces->length(); i++) {
InstanceKlass* iface = interfaces->at(i);
if (iface->is_in_error_state()) {
bad = true;
break;
}
}
}
if (bad) {
set_in_error_state();
}
}
return (old_state != is_in_error_state());
}
void InstanceKlass::set_class_loader_type(s2 loader_type) {
switch (loader_type) {
case ClassLoader::BOOT_LOADER:
_misc_flags |= _misc_is_shared_boot_class;
break;
case ClassLoader::PLATFORM_LOADER:
_misc_flags |= _misc_is_shared_platform_class;
break;
case ClassLoader::APP_LOADER:
_misc_flags |= _misc_is_shared_app_class;
break;
default:
ShouldNotReachHere();
break;
}
}
#if INCLUDE_JVMTI
static void clear_all_breakpoints(Method* m) {
m->clear_all_breakpoints();
}
#endif
void InstanceKlass::unload_class(InstanceKlass* ik) {
// Release dependencies.
ik->dependencies().remove_all_dependents();
// 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 (DumpSharedSpaces || DynamicDumpSharedSpaces) {
SystemDictionaryShared::remove_dumptime_info(ik);
}
if (log_is_enabled(Info, class, unload)) {
ResourceMark rm;
log_info(class, unload)("unloading class %s " INTPTR_FORMAT, ik->external_name(), p2i(ik));
}
Events::log_class_unloading(Thread::current(), 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);
}
assert(_dep_context == NULL,
"dependencies should already be cleaned");
#if INCLUDE_JVMTI
// 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);
_cached_class_file = NULL;
}
#endif
// 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);
}
void InstanceKlass::set_source_debug_extension(const 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;
}
}
const char* InstanceKlass::signature_name() const {
int hash_len = 0;
char hash_buf[40];
// If this is an unsafe anonymous class, append a hash to make the name unique
if (is_unsafe_anonymous()) {
intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
jio_snprintf(hash_buf, sizeof(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;
}
// Used to obtain the package name from a fully qualified class name.
Symbol* InstanceKlass::package_from_name(const Symbol* name, TRAPS) {
if (name == NULL) {
return NULL;
} else {
if (name->utf8_length() <= 0) {
return NULL;
}
ResourceMark rm;
const char* package_name = ClassLoader::package_from_name((const char*) name->as_C_string());
if (package_name == NULL) {
return NULL;
}
Symbol* pkg_name = SymbolTable::new_symbol(package_name);
return pkg_name;
}
}
ModuleEntry* InstanceKlass::module() const {
// For an unsafe anonymous class return the host class' module
if (is_unsafe_anonymous()) {
assert(unsafe_anonymous_host() != NULL, "unsafe anonymous class must have a host class");
return unsafe_anonymous_host()->module();
}
// Class is in a named package
if (!in_unnamed_package()) {
return _package_entry->module();
}
// Class is in an unnamed package, return its loader's unnamed module
return class_loader_data()->unnamed_module();
}
void InstanceKlass::set_package(ClassLoaderData* loader_data, TRAPS) {
// ensure java/ packages only loaded by boot or platform builtin loaders
check_prohibited_package(name(), loader_data, CHECK);
TempNewSymbol pkg_name = package_from_name(name(), CHECK);
if (pkg_name != NULL && loader_data != NULL) {
// Find in class loader's package entry table.
_package_entry = loader_data->packages()->lookup_only(pkg_name);
// If the package name is not found in the loader's package
// entry table, it is an indication that the package has not
// been defined. Consider it defined within the unnamed module.
if (_package_entry == NULL) {
ResourceMark rm;
if (!ModuleEntryTable::javabase_defined()) {
// Before java.base is defined during bootstrapping, define all packages in
// the java.base module. If a non-java.base package is erroneously placed
// in the java.base module it will be caught later when java.base
// is defined by ModuleEntryTable::verify_javabase_packages check.
assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
_package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
} else {
assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL");
_package_entry = loader_data->packages()->lookup(pkg_name,
loader_data->unnamed_module());
}
// A package should have been successfully created
assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
name()->as_C_string(), loader_data->loader_name_and_id());
}
if (log_is_enabled(Debug, module)) {
ResourceMark rm;
ModuleEntry* m = _package_entry->module();
log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
external_name(),
pkg_name->as_C_string(),
loader_data->loader_name_and_id(),
(m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
}
} else {
ResourceMark rm;
log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
external_name(),
(loader_data != NULL) ? loader_data->loader_name_and_id() : "NULL",
UNNAMED_MODULE);
}
}
// different versions of is_same_class_package
bool InstanceKlass::is_same_class_package(const Klass* class2) const {
oop classloader1 = this->class_loader();
PackageEntry* classpkg1 = this->package();
if (class2->is_objArray_klass()) {
class2 = ObjArrayKlass::cast(class2)->bottom_klass();
}
oop classloader2;
PackageEntry* classpkg2;
if (class2->is_instance_klass()) {
classloader2 = class2->class_loader();
classpkg2 = class2->package();
} else {
assert(class2->is_typeArray_klass(), "should be type array");
classloader2 = NULL;
classpkg2 = NULL;
}
// Same package is determined by comparing class loader
// and package entries. Both must be the same. This rule
// applies even to classes that are defined in the unnamed
// package, they still must have the same class loader.
if (oopDesc::equals(classloader1, classloader2) && (classpkg1 == classpkg2)) {
return true;
}
return false;
}
// return true if this class and other_class are in the same package. Classloader
// and classname information is enough to determine a class's package
bool InstanceKlass::is_same_class_package(oop other_class_loader,
const Symbol* other_class_name) const {
if (!oopDesc::equals(class_loader(), other_class_loader)) {
return false;
}
if (name()->fast_compare(other_class_name) == 0) {
return true;
}
{
ResourceMark rm;
bool bad_class_name = false;
const char* other_pkg =
ClassLoader::package_from_name((const char*) other_class_name->as_C_string(), &bad_class_name);
if (bad_class_name) {
return false;
}
// Check that package_from_name() returns NULL, not "", if there is no package.
assert(other_pkg == NULL || strlen(other_pkg) > 0, "package name is empty string");
const Symbol* const this_package_name =
this->package() != NULL ? this->package()->name() : NULL;
if (this_package_name == NULL || other_pkg == NULL) {
// One of the two doesn't have a package. Only return true if the other
// one also doesn't have a package.
return (const char*)this_package_name == other_pkg;
}
// Check if package is identical
return this_package_name->equals(other_pkg);
}
}
// Returns true iff super_method can be overridden by a method in targetclassname
// See JLS 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(const 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));
}
// Only boot and platform class loaders can define classes in "java/" packages.
void InstanceKlass::check_prohibited_package(Symbol* class_name,
ClassLoaderData* loader_data,
TRAPS) {
if (!loader_data->is_boot_class_loader_data() &&
!loader_data->is_platform_class_loader_data() &&
class_name != NULL) {
ResourceMark rm(THREAD);
char* name = class_name->as_C_string();
if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') {
TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK);
assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
name = pkg_name->as_C_string();
const char* class_loader_name = loader_data->loader_name_and_id();
StringUtils::replace_no_expand(name, "/", ".");
const char* msg_text1 = "Class loader (instance of): ";
const char* msg_text2 = " tried to load prohibited package name: ";
size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
}
}
return;
}
bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
constantPoolHandle i_cp(THREAD, constants());
for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
int ioff = iter.inner_class_info_index();
if (ioff != 0) {
// Check to see if the name matches the class we're looking for
// before attempting to find the class.
if (i_cp->klass_name_at_matches(this, ioff)) {
Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
if (this == inner_klass) {
*ooff = iter.outer_class_info_index();
*noff = iter.inner_name_index();
return true;
}
}
}
}
return false;
}
InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
InstanceKlass* outer_klass = NULL;
*inner_is_member = false;
int ooff = 0, noff = 0;
bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
if (has_inner_classes_attr) {
constantPoolHandle i_cp(THREAD, constants());
if (ooff != 0) {
Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
outer_klass = InstanceKlass::cast(ok);
*inner_is_member = true;
}
if (NULL == outer_klass) {
// It may be unsafe anonymous; try for that.
int encl_method_class_idx = enclosing_method_class_index();
if (encl_method_class_idx != 0) {
Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
outer_klass = InstanceKlass::cast(ok);
*inner_is_member = false;
}
}
}
// If no inner class attribute found for this class.
if (NULL == outer_klass) return NULL;
// Throws an exception if outer klass has not declared k as an inner klass
// We need evidence that each klass knows about the other, or else
// the system could allow a spoof of an inner class to gain access rights.
Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
return outer_klass;
}
jint InstanceKlass::compute_modifier_flags(TRAPS) const {
jint access = access_flags().as_int();
// But check if it happens to be member class.
InnerClassesIterator iter(this);
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 = constants()->klass_name_at(ioff);
if (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) {
ResourceMark rm(THREAD);
stringStream ss;
bool same_module = (module() == holder->module());
ss.print("Receiver class %s does not implement "
"the interface %s defining the method to be called "
"(%s%s%s)",
external_name(), holder->external_name(),
(same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
(same_module) ? "" : "; ",
(same_module) ? "" : holder->class_in_module_of_loader());
THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
}
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(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->is_old()) {
continue; // skip uninteresting entries
}
assert(!old_method->is_deleted(), "default methods may not be deleted");
Method* new_method = old_method->get_new_method();
default_methods()->at_put(index, new_method);
if (log_is_enabled(Info, redefine, class, update)) {
ResourceMark rm;
if (!(*trace_name_printed)) {
log_info(redefine, class, update)
("adjust: klassname=%s default methods from name=%s",
external_name(), old_method->method_holder()->external_name());
*trace_name_printed = true;
}
log_debug(redefine, class, update, vtables)
("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
{
// This is a short non-blocking critical region, so the no safepoint check is ok.
MutexLocker ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
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()));
}
}
// 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();
}
}
}
}
// Remove osr nmethod from the list. Return true if found and removed.
bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
// This is a short non-blocking critical region, so the no safepoint check is ok.
MutexLocker ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
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
bool found = false;
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) {
found = true;
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);
}
return found;
}
int InstanceKlass::mark_osr_nmethods(const Method* m) {
// This is a short non-blocking critical region, so the no safepoint check is ok.
MutexLocker 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.
MutexLocker ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
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.
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.
return osr;
}
best = osr;
}
}
}
osr = osr->osr_link();
}
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;
}
// -----------------------------------------------------------------------------------------------------
// 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 (MetaspaceObj::is_valid((Metadata*)e)) {
st->print(" ");
((Metadata*)e)->print_value_on(st);
}
st->cr();
}
}
static void print_vtable(vtableEntry* start, int len, outputStream* st) {
return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
}
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: "); Metadata::print_value_on_maybe_null(st, super()); 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("(" INTX_FORMAT " 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: "); Metadata::print_value_on_maybe_null(st, array_klasses()); 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"unsafe anonymous host class: "); Metadata::print_value_on_maybe_null(st, unsafe_anonymous_host()); 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"nest members: "); nest_members()->print_value_on(st); st->cr();
if (java_mirror() != NULL) {
st->print(BULLET"java mirror: ");
java_mirror()->print_value_on(st);
st->cr();
} else {
st->print_cr(BULLET"java mirror: NULL");
}
st->print(BULLET"vtable length %d (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(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(), p2i(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* ik = const_cast<InstanceKlass*>(this);
ik->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 length = java_lang_String::length(obj);
if (value != NULL &&
value->is_typeArray() &&
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: ");
Metadata::print_value_on_maybe_null(st, mirrored_klass);
st->cr();
Klass* array_klass = java_lang_Class::array_klass_acquire(obj);
st->print(BULLET"fake entry for array: ");
Metadata::print_value_on_maybe_null(st, array_klass);
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->is_instance_klass()) {
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();
}
}
bool InstanceKlass::verify_itable_index(int i) {
int method_count = klassItable::method_count_for_interface(this);
assert(i >= 0 && i < method_count, "index out of bounds");
return true;
}
#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();
}
void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
const char* module_name,
const ClassFileStream* cfs) const {
if (!log_is_enabled(Info, class, load)) {
return;
}
ResourceMark rm;
LogMessage(class, load) msg;
stringStream info_stream;
// Name and class hierarchy info
info_stream.print("%s", external_name());
// Source
if (cfs != NULL) {
if (cfs->source() != NULL) {
if (module_name != NULL) {
// When the boot loader created the stream, it didn't know the module name
// yet. Let's format it now.
if (cfs->from_boot_loader_modules_image()) {
info_stream.print(" source: jrt:/%s", module_name);
} else {
info_stream.print(" source: %s", cfs->source());
}
} else {
info_stream.print(" source: %s", cfs->source());
}
} else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
Thread* THREAD = Thread::current();
Klass* caller =
THREAD->is_Java_thread()
? ((JavaThread*)THREAD)->security_get_caller_class(1)
: NULL;
// caller can be NULL, for example, during a JVMTI VM_Init hook
if (caller != NULL) {
info_stream.print(" source: instance of %s", caller->external_name());
} else {
// source is unknown
}
} else {
oop class_loader = loader_data->class_loader();
info_stream.print(" source: %s", class_loader->klass()->external_name());
}
} else {
assert(this->is_shared(), "must be");
if (MetaspaceShared::is_shared_dynamic((void*)this)) {
info_stream.print(" source: shared objects file (top)");
} else {
info_stream.print(" source: shared objects file");
}
}
msg.info("%s", info_stream.as_string());
if (log_is_enabled(Debug, class, load)) {
stringStream debug_stream;
// Class hierarchy info
debug_stream.print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT,
p2i(this), p2i(superklass()));
// Interfaces
if (local_interfaces() != NULL && local_interfaces()->length() > 0) {
debug_stream.print(" interfaces:");
int length = local_interfaces()->length();
for (int i = 0; i < length; i++) {
debug_stream.print(" " INTPTR_FORMAT,
p2i(InstanceKlass::cast(local_interfaces()->at(i))));
}
}
// Class loader
debug_stream.print(" loader: [");
loader_data->print_value_on(&debug_stream);
debug_stream.print("]");
// Classfile checksum
if (cfs) {
debug_stream.print(" bytes: %d checksum: %08x",
cfs->length(),
ClassLoader::crc32(0, (const char*)cfs->buffer(),
cfs->length()));
}
msg.debug("%s", debug_stream.as_string());
}
}
#if INCLUDE_SERVICES
// Size Statistics
void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
Klass::collect_statistics(sz);
sz->_inst_size = wordSize * size_helper();
sz->_vtab_bytes = wordSize * vtable_length();
sz->_itab_bytes = wordSize * itable_length();
sz->_nonstatic_oopmap_bytes = wordSize * 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()));
n += (sz->_nest_members_bytes = sz->count_array(nest_members()));
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 BasicOopIterateClosure {
protected:
template <class T> void do_oop_work(T* p) {
oop obj = RawAccess<>::oop_load(p);
if (!oopDesc::is_oop_or_null(obj)) {
tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
Universe::print_on(tty);
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()) {
// $$$ 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() != NULL) {
guarantee(subklass()->is_klass(), "should be klass");
}
// Verify siblings
Klass* super = this->super();
Klass* sib = next_sibling();
if (sib != NULL) {
if (sib == this) {
fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
}
guarantee(sib->is_klass(), "should be klass");
guarantee(sib->super() == super, "siblings should have same superklass");
}
// Verify local interfaces
if (local_interfaces()) {
Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
for (int j = 0; j < local_interfaces->length(); j++) {
InstanceKlass* e = local_interfaces->at(j);
guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
}
}
// Verify transitive interfaces
if (transitive_interfaces() != NULL) {
Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
for (int j = 0; j < transitive_interfaces->length(); j++) {
InstanceKlass* 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* anonymous_host = unsafe_anonymous_host();
if (anonymous_host != NULL) {
guarantee(anonymous_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(&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();
}
}
void InstanceKlass::set_init_state(ClassState state) {
#ifdef ASSERT
bool good_state = is_shared() ? (_init_state <= state)
: (_init_state < state);
assert(good_state || state == allocated, "illegal state transition");
#endif
assert(_init_thread == NULL, "should be cleared before state change");
_init_state = (u1)state;
}
#if INCLUDE_JVMTI
// RedefineClasses() support for previous versions
// Globally, there is at least one previous version of a class to walk
// during class unloading, which is saved because old methods in the class
// are still running. Otherwise the previous version list is cleaned up.
bool InstanceKlass::_has_previous_versions = false;
// Returns true if there are previous versions of a class for class
// unloading only. Also resets the flag to false. purge_previous_version
// will set the flag to true if there are any left, i.e., if there's any
// work to do for next time. This is to avoid the expensive code cache
// walk in CLDG::clean_deallocate_lists().
bool InstanceKlass::has_previous_versions_and_reset() {
bool ret = _has_previous_versions;
log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
ret ? "true" : "false");
_has_previous_versions = false;
return ret;
}
// Purge previous versions before adding new previous versions of the class and
// during class unloading.
void InstanceKlass::purge_previous_version_list() {
assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
assert(has_been_redefined(), "Should only be called for main class");
// Quick exit.
if (previous_versions() == NULL) {
return;
}
// 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 = class_loader_data();
assert(loader_data != NULL, "should never be null");
ResourceMark rm;
log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
// previous versions are linked together through the InstanceKlass
InstanceKlass* pv_node = previous_versions();
InstanceKlass* last = this;
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.
log_trace(redefine, class, iklass, purge)
("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
// For debugging purposes.
pv_node->set_is_scratch_class();
// Unlink from previous version list.
assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
InstanceKlass* next = pv_node->previous_versions();
pv_node->link_previous_versions(NULL); // point next to NULL
last->link_previous_versions(next);
// Add to the deallocate list after unlinking
loader_data->add_to_deallocate_list(pv_node);
pv_node = next;
deleted_count++;
version++;
continue;
} else {
log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(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++;
// found a previous version for next time we do class unloading
_has_previous_versions = true;
}
// At least one method is live in this previous version.
// 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) {
log_trace(redefine, class, iklass, 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");
log_trace(redefine, class, iklass, purge)
("purge: %s(%s): prev method @%d in version @%d is alive",
method->name()->as_C_string(), method->signature()->as_C_string(), j, version);
}
}
}
// next previous version
last = pv_node;
pv_node = pv_node->previous_versions();
version++;
}
log_trace(redefine, class, iklass, purge)
("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
}
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
log_trace(redefine, class, iklass, 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(InstanceKlass* scratch_class,
int emcp_method_count) {
assert(Thread::current()->is_VM_thread(),
"only VMThread can add previous versions");
ResourceMark rm;
log_trace(redefine, class, iklass, add)
("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
// Clean out old previous versions for this class
purge_previous_version_list();
// 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()) {
log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
// For debugging purposes.
scratch_class->set_is_scratch_class();
scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
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 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);
log_trace(redefine, class, iklass, add)
("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
} else if (!old_method->is_obsolete()) {
log_trace(redefine, class, iklass, add)
("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
}
}
}
// Add previous version if any methods are still running.
// Set has_previous_version flag for processing during class unloading.
_has_previous_versions = true;
log_trace(redefine, class, iklass, 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()
#endif // INCLUDE_JVMTI
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;
}
#if INCLUDE_JVMTI
JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
return _cached_class_file;
}
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);
}
#endif