/* * Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "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/resolutionErrors.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/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.inline.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/recordComponent.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/biasedLocking.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; } // private: called to verify that k is a static member of this nest. // We know that k is an instance class in the same package and hence the // same classloader. bool InstanceKlass::has_nest_member(InstanceKlass* k, TRAPS) const { assert(!is_hidden(), "unexpected hidden class"); 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, THREAD); assert(!HAS_PENDING_EXCEPTION || PENDING_EXCEPTION->is_a(SystemDictionary::VirtualMachineError_klass()), "Exceptions should not be possible here"); 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 as it means one classloader // has defined two different classes with the same name! A compiler thread won't be // able to perform that loading but we can't exclude the compiler threads from // executing this logic. But it should actually be impossible to trigger loading here. Klass* k2 = _constants->klass_at(cp_index, THREAD); assert(!HAS_PENDING_EXCEPTION || PENDING_EXCEPTION->is_a(SystemDictionary::VirtualMachineError_klass()), "Exceptions should not be possible here"); 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; } // Called to verify that k is a permitted subclass of this class bool InstanceKlass::has_as_permitted_subclass(const InstanceKlass* k) const { Thread* THREAD = Thread::current(); assert(k != NULL, "sanity check"); assert(_permitted_subclasses != NULL && _permitted_subclasses != Universe::the_empty_short_array(), "unexpected empty _permitted_subclasses array"); if (log_is_enabled(Trace, class, sealed)) { ResourceMark rm(THREAD); log_trace(class, sealed)("Checking for permitted subclass of %s in %s", k->external_name(), this->external_name()); } // Check that the class and its super are in the same module. if (k->module() != this->module()) { ResourceMark rm(THREAD); log_trace(class, sealed)("Check failed for same module of permitted subclass %s and sealed class %s", k->external_name(), this->external_name()); return false; } if (!k->is_public() && !is_same_class_package(k)) { ResourceMark rm(THREAD); log_trace(class, sealed)("Check failed, subclass %s not public and not in the same package as sealed class %s", k->external_name(), this->external_name()); return false; } // 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 < _permitted_subclasses->length(); i++) { int cp_index = _permitted_subclasses->at(i); if (_constants->tag_at(cp_index).is_klass()) { Klass* k2 = _constants->klass_at(cp_index, THREAD); assert(!HAS_PENDING_EXCEPTION, "Unexpected exception"); if (k2 == k) { log_trace(class, sealed)("- class is listed at permitted_subclasses[%d] => cp[%d]", i, cp_index); return true; } } else { Symbol* name = _constants->klass_name_at(cp_index); if (name == k->name()) { log_trace(class, sealed)("- Found it at permitted_subclasses[%d] => cp[%d]", i, cp_index); return true; } } } log_trace(class, sealed)("- class is NOT a permitted subclass!"); return false; } // Return nest-host class, resolving, validating and saving it if needed. // In cases where this is called from a thread that cannot 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. Otherwise the _nest_host is always // set once this method returns. // Any errors from nest-host resolution must be preserved so they can be queried // from higher-level access checking code, and reported as part of access checking // exceptions. // VirtualMachineErrors are propagated with a NULL return. // Under any conditions where the _nest_host can be set to non-NULL the resulting // value of it and, if applicable, the nest host resolution/validation error, // are idempotent. InstanceKlass* InstanceKlass::nest_host(TRAPS) { InstanceKlass* nest_host_k = _nest_host; if (nest_host_k != NULL) { return nest_host_k; } ResourceMark rm(THREAD); // need to resolve and save our nest-host class. 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()) { log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread", this->external_name()); return NULL; // sentinel to say "try again from a different context" } 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) { if (PENDING_EXCEPTION->is_a(SystemDictionary::VirtualMachineError_klass())) { return NULL; // propagate VMEs } stringStream ss; char* target_host_class = _constants->klass_name_at(_nest_host_index)->as_C_string(); ss.print("Nest host resolution of %s with host %s failed: ", this->external_name(), target_host_class); java_lang_Throwable::print(PENDING_EXCEPTION, &ss); const char* msg = ss.as_string(true /* on C-heap */); constantPoolHandle cph(THREAD, constants()); SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg); CLEAR_PENDING_EXCEPTION; log_trace(class, nestmates)("%s", msg); } else { // 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 the class is // its own nest-host. 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, THREAD); // exception is rare, perhaps impossible if (!HAS_PENDING_EXCEPTION) { if (is_member) { _nest_host = nest_host_k; // save resolved nest-host value log_trace(class, nestmates)("Resolved nest-host of %s to %s", this->external_name(), k->external_name()); return nest_host_k; } else { error = "current type is not listed as a nest member"; } } else { if (PENDING_EXCEPTION->is_a(SystemDictionary::VirtualMachineError_klass())) { return NULL; // propagate VMEs } stringStream ss; ss.print("exception on member check: "); java_lang_Throwable::print(PENDING_EXCEPTION, &ss); error = ss.as_string(); } } else { error = "host is not an instance class"; } } else { error = "types are in different packages"; } // something went wrong, so record what and log it { stringStream ss; ss.print("Type %s (loader: %s) is not a nest member of 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); const char* msg = ss.as_string(true /* on C-heap */); constantPoolHandle cph(THREAD, constants()); SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg); log_trace(class, nestmates)("%s", msg); } } } else { log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self", this->external_name()); } // Either not in an explicit nest, or else an error occurred, so // the nest-host is set to `this`. Any thread that sees this assignment // will also see any setting of nest_host_error(), if applicable. return (_nest_host = this); } // Dynamic nest member support: set this class's nest host to the given class. // This occurs as part of the class definition, as soon as the instanceKlass // has been created and doesn't require further resolution. The code: // lookup().defineHiddenClass(bytes_for_X, NESTMATE); // results in: // class_of_X.set_nest_host(lookup().lookupClass().getNestHost()) // If it has an explicit _nest_host_index or _nest_members, these will be ignored. // We also know the "host" is a valid nest-host in the same package so we can // assert some of those facts. void InstanceKlass::set_nest_host(InstanceKlass* host, TRAPS) { assert(is_hidden(), "must be a hidden class"); assert(host != NULL, "NULL nest host specified"); assert(_nest_host == NULL, "current class has resolved nest-host"); assert(nest_host_error(THREAD) == NULL, "unexpected nest host resolution error exists: %s", nest_host_error(THREAD)); assert((host->_nest_host == NULL && host->_nest_host_index == 0) || (host->_nest_host == host), "proposed host is not a valid nest-host"); // Can't assert this as package is not set yet: // assert(is_same_class_package(host), "proposed host is in wrong package"); if (log_is_enabled(Trace, class, nestmates)) { ResourceMark rm(THREAD); const char* msg = ""; // a hidden class does not expect a statically defined nest-host if (_nest_host_index > 0) { msg = "(the NestHost attribute in the current class is ignored)"; } else if (_nest_members != NULL && _nest_members != Universe::the_empty_short_array()) { msg = "(the NestMembers attribute in the current class is ignored)"; } log_trace(class, nestmates)("Injected type %s into the nest of %s %s", this->external_name(), host->external_name(), msg); } // set dynamic nest host _nest_host = host; // Record dependency to keep nest host from being unloaded before this class. ClassLoaderData* this_key = class_loader_data(); this_key->record_dependency(host); } // 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. // Any exceptions (i.e. VMEs) are propagated. 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. InstanceKlass* cur_host = nest_host(CHECK_false); if (cur_host == NULL) { return false; } Klass* k_nest_host = k->nest_host(CHECK_false); if (k_nest_host == NULL) { return false; } bool access = (cur_host == k_nest_host); 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; } const char* InstanceKlass::nest_host_error(TRAPS) { if (_nest_host_index == 0) { return NULL; } else { constantPoolHandle cph(THREAD, constants()); return SystemDictionary::find_nest_host_error(cph, (int)_nest_host_index); } } InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) { bool is_hidden_or_anonymous = parser.is_hidden() || parser.is_unsafe_anonymous(); 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(is_hidden_or_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::_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(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* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) { Array* vtable_indices = MetadataFactory::new_array(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(NULL), _permitted_subclasses(NULL), _record_components(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()), _nest_host_index(0), _init_state(allocated), _reference_type(parser.reference_type()), _init_thread(NULL) { set_vtable_length(parser.vtable_size()); set_kind(kind); set_access_flags(parser.access_flags()); if (parser.is_hidden()) set_is_hidden(); 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?"); // Set biased locking bit for all instances of this class; it will be // cleared if revocation occurs too often for this type if (UseBiasedLocking && BiasedLocking::enabled()) { set_prototype_header(markWord::biased_locking_prototype()); } } void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data, Array* 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(loader_data, methods); } } void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data, const Klass* super_klass, Array* local_interfaces, Array* transitive_interfaces) { // Only deallocate transitive interfaces if not empty, same as super class // or same as local interfaces. See code in parseClassFile. Array* 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* sti = (super_klass == NULL) ? NULL : InstanceKlass::cast(super_klass)->transitive_interfaces(); if (ti != sti && ti != NULL && !ti->is_shared()) { MetadataFactory::free_array(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(loader_data, local_interfaces); } } void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data, Array* record_components) { if (record_components != NULL && !record_components->is_shared()) { for (int i = 0; i < record_components->length(); i++) { RecordComponent* record_component = record_components->at(i); MetadataFactory::free_metadata(loader_data, record_component); } MetadataFactory::free_array(loader_data, record_components); } } // 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 points to, which includes // reference counting symbol names. release_C_heap_structures_internal(); deallocate_methods(loader_data, methods()); set_methods(NULL); deallocate_record_components(loader_data, record_components()); set_record_components(NULL); if (method_ordering() != NULL && method_ordering() != Universe::the_empty_int_array() && !method_ordering()->is_shared()) { MetadataFactory::free_array(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(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(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(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(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(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(loader_data, nest_members()); } set_nest_members(NULL); if (permitted_subclasses() != NULL && permitted_subclasses() != Universe::the_empty_short_array() && !permitted_subclasses()->is_shared()) { MetadataFactory::free_array(loader_data, permitted_subclasses()); } set_permitted_subclasses(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 (Arguments::is_dumping_archive()) { SystemDictionaryShared::remove_dumptime_info(this); } } bool InstanceKlass::is_sealed() const { return _permitted_subclasses != NULL && _permitted_subclasses != Universe::the_empty_short_array() && _permitted_subclasses->length() > 0; } bool InstanceKlass::should_be_initialized() const { return !is_initialized(); } klassItable InstanceKlass::itable() const { return klassItable(const_cast(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::clear_init_lock(java_mirror()); 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 && SystemDictionaryShared::has_class_failed_verification(this)) { // 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* 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 // 1) the class is loaded by custom class loader or // 2) the class is loaded by built-in class loader but failed to add archived loader constraints bool need_init_table = true; if (is_shared() && SystemDictionaryShared::check_linking_constraints(this, THREAD)) { need_init_table = false; } if (need_init_table) { vtable().initialize_vtable(true, CHECK_false); itable().initialize_itable(true, CHECK_false); } #ifdef ASSERT 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.wait_uninterruptibly(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 = Atomic::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_locked_or_safepoint(Compile_lock); assert(is_interface(), "not interface"); Klass* volatile* addr = adr_implementor(); assert(addr != NULL, "null addr"); if (addr != NULL) { Atomic::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) { if (Universe::is_fully_initialized()) { 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 && ik != k) { // 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* InstanceKlass::compute_secondary_supers(int num_extra_slots, Array* transitive_interfaces) { // The secondaries are the implemented interfaces. Array* 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 is NOT a supertype of Array, // (but it's safe to do here because we won't write into _secondary_supers from this point on). set_secondary_supers((Array*)(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* secondaries = new GrowableArray(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(THREAD); JavaThread *jt = (JavaThread *)THREAD; { // Atomic creation of array_klasses MutexLocker ma(THREAD, MultiArray_lock); // Check if update has already taken place if (array_klasses() == NULL) { ObjArrayKlass* 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 = 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(THREAD); 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 = Atomic::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 Atomic::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::contains_field_offset(int offset) { fieldDescriptor fd; return find_field_from_offset(offset, false, &fd); } 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(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(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(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(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(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) array_klasses()->array_klasses_do(f, THREAD); } void InstanceKlass::array_klasses_do(void f(Klass* k)) { if (array_klasses() != NULL) array_klasses()->array_klasses_do(f); } #ifdef ASSERT static int linear_search(const Array* 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 bool InstanceKlass::_disable_method_binary_search = false; NOINLINE int linear_search(const Array* methods, const Symbol* name) { int len = methods->length(); int l = 0; int h = len - 1; while (l <= h) { Method* m = methods->at(l); if (m->name() == name) { return l; } l++; } return -1; } inline int InstanceKlass::quick_search(const Array* methods, const Symbol* name) { if (_disable_method_binary_search) { assert(DynamicDumpSharedSpaces, "must be"); // At the final stage of dynamic dumping, the methods array may not be sorted // by ascending addresses of their names, so we can't use binary search anymore. // However, methods with the same name are still laid out consecutively inside the // methods array, so let's look for the first one that matches. return linear_search(methods, name); } int len = methods->length(); int l = 0; int h = len - 1; // methods are sorted by ascending addresses of their names, so do binary search 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* 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* 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* 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* 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* 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 = quick_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* methods, const Symbol* name, int* end_ptr) { assert(end_ptr != NULL, "just checking"); int start = quick_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* 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* 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* 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, Mutex::_no_safepoint_check_flag); 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, Mutex::_no_safepoint_check_flag); 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. Atomic::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 = Atomic::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, impl, (Klass*)NULL) == 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* 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_hidden_or_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 (Arguments::is_dumping_archive()) { // (2) We are running -Xshare:dump or -XX:ArchiveClassesAtExit to create a shared archive return true; } if (UseAOT && is_hidden_or_anonymous) { // (3) We are using AOT code from a shared library and see a hidden or 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); #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); it->push(&_permitted_subclasses); it->push(&_record_components); } void InstanceKlass::remove_unshareable_info() { Klass::remove_unshareable_info(); if (SystemDictionaryShared::has_class_failed_verification(this)) { // Classes are attempted to link during dumping and may fail, // but these classes are still in the dictionary and class list in CLD. // If the class has failed verification, 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; { // Otherwise this needs to take out the Compile_lock. assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint"); 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; _jvmti_cached_class_field_map = 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; _package_entry = NULL; _dep_context_last_cleaned = 0; } 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, PackageEntry* pkg_entry, 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 * 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); } // Initialize current biased locking state. if (UseBiasedLocking && BiasedLocking::enabled()) { set_prototype_header(markWord::biased_locking_prototype()); } } void InstanceKlass::set_shared_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; } } void InstanceKlass::assign_class_loader_type() { ClassLoaderData *cld = class_loader_data(); if (cld->is_boot_class_loader_data()) { set_shared_class_loader_type(ClassLoader::BOOT_LOADER); } else if (cld->is_platform_class_loader_data()) { set_shared_class_loader_type(ClassLoader::PLATFORM_LOADER); } else if (cld->is_system_class_loader_data()) { set_shared_class_loader_type(ClassLoader::APP_LOADER); } } #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 (Arguments::is_dumping_archive()) { 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 } static void method_release_C_heap_structures(Method* m) { m->release_C_heap_structures(); } void InstanceKlass::release_C_heap_structures() { // Clean up C heap release_C_heap_structures_internal(); constants()->release_C_heap_structures(); // Deallocate and call destructors for MDO mutexes methods_do(method_release_C_heap_structures); } void InstanceKlass::release_C_heap_structures_internal() { Klass::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 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++] = JVM_SIGNATURE_CLASS; // Add the actual class name for (int src_index = 0; src_index < src_length; ) { dest[dest_index++] = src[src_index++]; } if (is_hidden()) { // Replace the last '+' with a '.'. for (int index = (int)src_length; index > 0; index--) { if (dest[index] == '+') { dest[index] = JVM_SIGNATURE_DOT; break; } } } // 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++] = JVM_SIGNATURE_ENDCLASS; dest[dest_index] = '\0'; return dest; } 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(); } if (is_hidden() && in_unnamed_package() && class_loader_data()->has_class_mirror_holder()) { // For a non-strong hidden class defined to an unnamed package, // its (class held) CLD will not have an unnamed module created for it. // Two choices to find the correct ModuleEntry: // 1. If hidden class is within a nest, use nest host's module // 2. Find the unnamed module off from the class loader // For now option #2 is used since a nest host is not set until // after the instance class is created in jvm_lookup_define_class(). if (class_loader_data()->is_boot_class_loader_data()) { return ClassLoaderData::the_null_class_loader_data()->unnamed_module(); } else { oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader()); assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module"); return java_lang_Module::module_entry(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, PackageEntry* pkg_entry, TRAPS) { // ensure java/ packages only loaded by boot or platform builtin loaders // not needed for shared class since CDS does not archive prohibited classes. if (!is_shared()) { check_prohibited_package(name(), loader_data, CHECK); } TempNewSymbol pkg_name = pkg_entry != NULL ? pkg_entry->name() : ClassLoader::package_from_class_name(name()); if (pkg_name != NULL && loader_data != NULL) { // Find in class loader's package entry table. _package_entry = pkg_entry != NULL ? pkg_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) { 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 DEBUG_ONLY(ResourceMark rm(THREAD)); 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(THREAD); 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(THREAD); 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); } } // Function set_classpath_index checks if the package of the InstanceKlass is in the // boot loader's package entry table. If so, then it sets the classpath_index // in the package entry record. // // The classpath_index field is used to find the entry on the boot loader class // path for packages with classes loaded by the boot loader from -Xbootclasspath/a // in an unnamed module. It is also used to indicate (for all packages whose // classes are loaded by the boot loader) that at least one of the package's // classes has been loaded. void InstanceKlass::set_classpath_index(s2 path_index, TRAPS) { if (_package_entry != NULL) { DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();) assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same"); assert(path_index != -1, "Unexpected classpath_index"); _package_entry->set_classpath_index(path_index); } } // 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 ((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 (class_loader() != other_class_loader) { return false; } if (name()->fast_compare(other_class_name) == 0) { return true; } { ResourceMark rm; bool bad_class_name = false; TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name); if (bad_class_name) { return false; } // Check that package_from_class_name() returns NULL, not "", if there is no package. assert(other_pkg == NULL || other_pkg->utf8_length() > 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 this_package_name == other_pkg; } // Check if package is identical return this_package_name->fast_compare(other_pkg) == 0; } } // 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 = ClassLoader::package_from_class_name(class_name); 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 a local or anonymous class; 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) { assert_lock_strong(CompiledMethod_lock); #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() COMPILER2_PRESENT(|| StressRecompilation), "redundant OSR recompilation detected. memory leak in CodeCache!"); } #endif // only one compilation can be active { 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(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_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) { MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_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 { MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_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(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_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_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 (record_components() != NULL) { st->print(BULLET"record components: "); record_components()->print_value_on(st); st->cr(); } st->print(BULLET"permitted subclasses: "); permitted_subclasses()->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(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()); } } // Verification class VerifyFieldClosure: public BasicOopIterateClosure { protected: template 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* 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* 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* 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* method_ordering = this->method_ordering(); int length = method_ordering->length(); if (JvmtiExport::can_maintain_original_method_order() || ((UseSharedSpaces || Arguments::is_dumping_archive()) && 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* 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 (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_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* 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_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* 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