| /* |
| * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "classfile/javaClasses.hpp" |
| #include "classfile/loaderConstraints.hpp" |
| #include "classfile/symbolTable.hpp" |
| #include "classfile/systemDictionary.hpp" |
| #include "gc_implementation/shared/spaceDecorator.hpp" |
| #include "memory/classify.hpp" |
| #include "memory/filemap.hpp" |
| #include "memory/oopFactory.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "oops/methodDataOop.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "runtime/javaCalls.hpp" |
| #include "runtime/signature.hpp" |
| #include "runtime/vmThread.hpp" |
| #include "runtime/vm_operations.hpp" |
| #include "utilities/copy.hpp" |
| |
| |
| // Closure to set up the fingerprint field for all methods. |
| |
| class FingerprintMethodsClosure: public ObjectClosure { |
| public: |
| void do_object(oop obj) { |
| if (obj->is_method()) { |
| methodOop mobj = (methodOop)obj; |
| ResourceMark rm; |
| (new Fingerprinter(mobj))->fingerprint(); |
| } |
| } |
| }; |
| |
| |
| |
| // Closure to set the hash value (String.hash field) in all of the |
| // String objects in the heap. Setting the hash value is not required. |
| // However, setting the value in advance prevents the value from being |
| // written later, increasing the likelihood that the shared page contain |
| // the hash can be shared. |
| // |
| // NOTE THAT the algorithm in StringTable::hash_string() MUST MATCH the |
| // algorithm in java.lang.String.hashCode(). |
| |
| class StringHashCodeClosure: public OopClosure { |
| private: |
| Thread* THREAD; |
| int hash_offset; |
| public: |
| StringHashCodeClosure(Thread* t) { |
| THREAD = t; |
| hash_offset = java_lang_String::hash_offset_in_bytes(); |
| } |
| |
| void do_oop(oop* p) { |
| if (p != NULL) { |
| oop obj = *p; |
| if (obj->klass() == SystemDictionary::String_klass()) { |
| |
| int hash = java_lang_String::hash_string(obj); |
| obj->int_field_put(hash_offset, hash); |
| } |
| } |
| } |
| void do_oop(narrowOop* p) { ShouldNotReachHere(); } |
| }; |
| |
| |
| // Remove data from objects which should not appear in the shared file |
| // (as it pertains only to the current JVM). |
| |
| class RemoveUnshareableInfoClosure : public ObjectClosure { |
| public: |
| void do_object(oop obj) { |
| // Zap data from the objects which is pertains only to this JVM. We |
| // want that data recreated in new JVMs when the shared file is used. |
| if (obj->is_method()) { |
| ((methodOop)obj)->remove_unshareable_info(); |
| } |
| else if (obj->is_klass()) { |
| Klass::cast((klassOop)obj)->remove_unshareable_info(); |
| } |
| |
| // Don't save compiler related special oops (shouldn't be any yet). |
| if (obj->is_methodData() || obj->is_compiledICHolder()) { |
| ShouldNotReachHere(); |
| } |
| } |
| }; |
| |
| |
| static bool mark_object(oop obj) { |
| if (obj != NULL && |
| !obj->is_shared() && |
| !obj->is_forwarded() && |
| !obj->is_gc_marked()) { |
| obj->set_mark(markOopDesc::prototype()->set_marked()); |
| return true; |
| } |
| |
| return false; |
| } |
| |
| |
| class MoveSymbols : public SymbolClosure { |
| private: |
| char* _start; |
| char* _end; |
| char* _top; |
| int _count; |
| |
| bool in_shared_space(Symbol* sym) const { |
| return (char*)sym >= _start && (char*)sym < _end; |
| } |
| |
| Symbol* get_shared_copy(Symbol* sym) { |
| return sym->refcount() > 0 ? NULL : (Symbol*)(_start - sym->refcount()); |
| } |
| |
| Symbol* make_shared_copy(Symbol* sym) { |
| Symbol* new_sym = (Symbol*)_top; |
| int size = sym->object_size(); |
| _top += size * HeapWordSize; |
| if (_top <= _end) { |
| Copy::disjoint_words((HeapWord*)sym, (HeapWord*)new_sym, size); |
| // Encode a reference to the copy as a negative distance from _start |
| // When a symbol is being copied to a shared space |
| // during CDS archive creation, the original symbol is marked |
| // as relocated by putting a negative value to its _refcount field, |
| // This value is also used to find where exactly the shared copy is |
| // (see MoveSymbols::get_shared_copy), so that the other references |
| // to this symbol could be changed to point to the shared copy. |
| sym->_refcount = (int)(_start - (char*)new_sym); |
| // Mark the symbol in the shared archive as immortal so it is read only |
| // and not refcounted. |
| new_sym->_refcount = -1; |
| _count++; |
| } else { |
| report_out_of_shared_space(SharedMiscData); |
| } |
| return new_sym; |
| } |
| |
| public: |
| MoveSymbols(char* top, char* end) : |
| _start(top), _end(end), _top(top), _count(0) { } |
| |
| char* get_top() const { return _top; } |
| int count() const { return _count; } |
| |
| void do_symbol(Symbol** p) { |
| Symbol* sym = load_symbol(p); |
| if (sym != NULL && !in_shared_space(sym)) { |
| Symbol* new_sym = get_shared_copy(sym); |
| if (new_sym == NULL) { |
| // The symbol has not been relocated yet; copy it to _top address |
| assert(sym->refcount() > 0, "should have positive reference count"); |
| new_sym = make_shared_copy(sym); |
| } |
| // Make the reference point to the shared copy of the symbol |
| store_symbol(p, new_sym); |
| } |
| } |
| }; |
| |
| |
| // Closure: mark objects closure. |
| |
| class MarkObjectsOopClosure : public OopClosure { |
| public: |
| void do_oop(oop* p) { mark_object(*p); } |
| void do_oop(narrowOop* p) { ShouldNotReachHere(); } |
| }; |
| |
| |
| class MarkObjectsSkippingKlassesOopClosure : public OopClosure { |
| public: |
| void do_oop(oop* pobj) { |
| oop obj = *pobj; |
| if (obj != NULL && |
| !obj->is_klass()) { |
| mark_object(obj); |
| } |
| } |
| void do_oop(narrowOop* pobj) { ShouldNotReachHere(); } |
| }; |
| |
| |
| static void mark_object_recursive_skipping_klasses(oop obj) { |
| mark_object(obj); |
| if (obj != NULL) { |
| MarkObjectsSkippingKlassesOopClosure mark_all; |
| obj->oop_iterate(&mark_all); |
| } |
| } |
| |
| |
| // Closure: mark common read-only objects |
| |
| class MarkCommonReadOnly : public ObjectClosure { |
| private: |
| MarkObjectsOopClosure mark_all; |
| public: |
| void do_object(oop obj) { |
| |
| // Mark all constMethod objects. |
| |
| if (obj->is_constMethod()) { |
| mark_object(obj); |
| mark_object(constMethodOop(obj)->stackmap_data()); |
| // Exception tables are needed by ci code during compilation. |
| mark_object(constMethodOop(obj)->exception_table()); |
| } |
| |
| // Mark objects referenced by klass objects which are read-only. |
| |
| else if (obj->is_klass()) { |
| Klass* k = Klass::cast((klassOop)obj); |
| mark_object(k->secondary_supers()); |
| |
| // The METHODS() OBJARRAYS CANNOT BE MADE READ-ONLY, even though |
| // it is never modified. Otherwise, they will be pre-marked; the |
| // GC marking phase will skip them; and by skipping them will fail |
| // to mark the methods objects referenced by the array. |
| |
| if (obj->blueprint()->oop_is_instanceKlass()) { |
| instanceKlass* ik = instanceKlass::cast((klassOop)obj); |
| mark_object(ik->method_ordering()); |
| mark_object(ik->local_interfaces()); |
| mark_object(ik->transitive_interfaces()); |
| mark_object(ik->fields()); |
| |
| mark_object(ik->class_annotations()); |
| |
| mark_object_recursive_skipping_klasses(ik->fields_annotations()); |
| mark_object_recursive_skipping_klasses(ik->methods_annotations()); |
| mark_object_recursive_skipping_klasses(ik->methods_parameter_annotations()); |
| mark_object_recursive_skipping_klasses(ik->methods_default_annotations()); |
| |
| typeArrayOop inner_classes = ik->inner_classes(); |
| if (inner_classes != NULL) { |
| mark_object(inner_classes); |
| } |
| } |
| } |
| } |
| }; |
| |
| |
| // Closure: find symbol references in Java Heap objects |
| |
| class CommonSymbolsClosure : public ObjectClosure { |
| private: |
| SymbolClosure* _closure; |
| public: |
| CommonSymbolsClosure(SymbolClosure* closure) : _closure(closure) { } |
| |
| void do_object(oop obj) { |
| |
| // Traverse symbols referenced by method objects. |
| |
| if (obj->is_method()) { |
| methodOop m = methodOop(obj); |
| constantPoolOop constants = m->constants(); |
| _closure->do_symbol(constants->symbol_at_addr(m->name_index())); |
| _closure->do_symbol(constants->symbol_at_addr(m->signature_index())); |
| } |
| |
| // Traverse symbols referenced by klass objects which are read-only. |
| |
| else if (obj->is_klass()) { |
| Klass* k = Klass::cast((klassOop)obj); |
| k->shared_symbols_iterate(_closure); |
| |
| if (obj->blueprint()->oop_is_instanceKlass()) { |
| instanceKlass* ik = instanceKlass::cast((klassOop)obj); |
| instanceKlassHandle ik_h((klassOop)obj); |
| InnerClassesIterator iter(ik_h); |
| constantPoolOop constants = ik->constants(); |
| for (; !iter.done(); iter.next()) { |
| int index = iter.inner_name_index(); |
| |
| if (index != 0) { |
| _closure->do_symbol(constants->symbol_at_addr(index)); |
| } |
| } |
| } |
| } |
| |
| // Traverse symbols referenced by other constantpool entries. |
| |
| else if (obj->is_constantPool()) { |
| constantPoolOop(obj)->shared_symbols_iterate(_closure); |
| } |
| } |
| }; |
| |
| |
| // Closure: mark char arrays used by strings |
| |
| class MarkStringValues : public ObjectClosure { |
| private: |
| MarkObjectsOopClosure mark_all; |
| public: |
| void do_object(oop obj) { |
| |
| // Character arrays referenced by String objects are read-only. |
| |
| if (java_lang_String::is_instance(obj)) { |
| mark_object(java_lang_String::value(obj)); |
| } |
| } |
| }; |
| |
| |
| #ifdef DEBUG |
| // Closure: Check for objects left in the heap which have not been moved. |
| |
| class CheckRemainingObjects : public ObjectClosure { |
| private: |
| int count; |
| |
| public: |
| CheckRemainingObjects() { |
| count = 0; |
| } |
| |
| void do_object(oop obj) { |
| if (!obj->is_shared() && |
| !obj->is_forwarded()) { |
| ++count; |
| if (Verbose) { |
| tty->print("Unreferenced object: "); |
| obj->print_on(tty); |
| } |
| } |
| } |
| |
| void status() { |
| tty->print_cr("%d objects no longer referenced, not shared.", count); |
| } |
| }; |
| #endif |
| |
| |
| // Closure: Mark remaining objects read-write, except Strings. |
| |
| class MarkReadWriteObjects : public ObjectClosure { |
| private: |
| MarkObjectsOopClosure mark_objects; |
| public: |
| void do_object(oop obj) { |
| |
| // The METHODS() OBJARRAYS CANNOT BE MADE READ-ONLY, even though |
| // it is never modified. Otherwise, they will be pre-marked; the |
| // GC marking phase will skip them; and by skipping them will fail |
| // to mark the methods objects referenced by the array. |
| |
| if (obj->is_klass()) { |
| mark_object(obj); |
| Klass* k = klassOop(obj)->klass_part(); |
| mark_object(k->java_mirror()); |
| if (obj->blueprint()->oop_is_instanceKlass()) { |
| instanceKlass* ik = (instanceKlass*)k; |
| mark_object(ik->methods()); |
| mark_object(ik->constants()); |
| } |
| if (obj->blueprint()->oop_is_javaArray()) { |
| arrayKlass* ak = (arrayKlass*)k; |
| mark_object(ak->component_mirror()); |
| } |
| return; |
| } |
| |
| // Mark constantPool tags and the constantPoolCache. |
| |
| else if (obj->is_constantPool()) { |
| constantPoolOop pool = constantPoolOop(obj); |
| mark_object(pool->cache()); |
| pool->shared_tags_iterate(&mark_objects); |
| return; |
| } |
| |
| // Mark all method objects. |
| |
| if (obj->is_method()) { |
| mark_object(obj); |
| } |
| } |
| }; |
| |
| |
| // Closure: Mark String objects read-write. |
| |
| class MarkStringObjects : public ObjectClosure { |
| private: |
| MarkObjectsOopClosure mark_objects; |
| public: |
| void do_object(oop obj) { |
| |
| // Mark String objects referenced by constant pool entries. |
| |
| if (obj->is_constantPool()) { |
| constantPoolOop pool = constantPoolOop(obj); |
| pool->shared_strings_iterate(&mark_objects); |
| return; |
| } |
| } |
| }; |
| |
| |
| // Move objects matching specified type (ie. lock_bits) to the specified |
| // space. |
| |
| class MoveMarkedObjects : public ObjectClosure { |
| private: |
| OffsetTableContigSpace* _space; |
| bool _read_only; |
| |
| public: |
| MoveMarkedObjects(OffsetTableContigSpace* space, bool read_only) { |
| _space = space; |
| _read_only = read_only; |
| } |
| |
| void do_object(oop obj) { |
| if (obj->is_shared()) { |
| return; |
| } |
| if (obj->is_gc_marked() && obj->forwardee() == NULL) { |
| int s = obj->size(); |
| oop sh_obj = (oop)_space->allocate(s); |
| if (sh_obj == NULL) { |
| report_out_of_shared_space(_read_only ? SharedReadOnly : SharedReadWrite); |
| } |
| if (PrintSharedSpaces && Verbose && WizardMode) { |
| tty->print_cr("\nMoveMarkedObjects: " PTR_FORMAT " -> " PTR_FORMAT " %s", obj, sh_obj, |
| (_read_only ? "ro" : "rw")); |
| } |
| Copy::aligned_disjoint_words((HeapWord*)obj, (HeapWord*)sh_obj, s); |
| obj->forward_to(sh_obj); |
| if (_read_only) { |
| // Readonly objects: set hash value to self pointer and make gc_marked. |
| sh_obj->forward_to(sh_obj); |
| } else { |
| sh_obj->init_mark(); |
| } |
| } |
| } |
| }; |
| |
| static void mark_and_move(oop obj, MoveMarkedObjects* move) { |
| if (mark_object(obj)) move->do_object(obj); |
| } |
| |
| enum order_policy { |
| OP_favor_startup = 0, |
| OP_balanced = 1, |
| OP_favor_runtime = 2 |
| }; |
| |
| static void mark_and_move_for_policy(order_policy policy, oop obj, MoveMarkedObjects* move) { |
| if (SharedOptimizeColdStartPolicy >= policy) mark_and_move(obj, move); |
| } |
| |
| class MarkAndMoveOrderedReadOnly : public ObjectClosure { |
| private: |
| MoveMarkedObjects *_move_ro; |
| |
| public: |
| MarkAndMoveOrderedReadOnly(MoveMarkedObjects *move_ro) : _move_ro(move_ro) {} |
| |
| void do_object(oop obj) { |
| if (obj->is_klass() && obj->blueprint()->oop_is_instanceKlass()) { |
| instanceKlass* ik = instanceKlass::cast((klassOop)obj); |
| int i; |
| |
| if (ik->super() != NULL) { |
| do_object(ik->super()); |
| } |
| |
| objArrayOop interfaces = ik->local_interfaces(); |
| mark_and_move_for_policy(OP_favor_startup, interfaces, _move_ro); |
| for(i = 0; i < interfaces->length(); i++) { |
| klassOop k = klassOop(interfaces->obj_at(i)); |
| do_object(k); |
| } |
| |
| objArrayOop methods = ik->methods(); |
| for(i = 0; i < methods->length(); i++) { |
| methodOop m = methodOop(methods->obj_at(i)); |
| mark_and_move_for_policy(OP_favor_startup, m->constMethod(), _move_ro); |
| mark_and_move_for_policy(OP_favor_runtime, m->constMethod()->exception_table(), _move_ro); |
| mark_and_move_for_policy(OP_favor_runtime, m->constMethod()->stackmap_data(), _move_ro); |
| } |
| |
| mark_and_move_for_policy(OP_favor_startup, ik->transitive_interfaces(), _move_ro); |
| mark_and_move_for_policy(OP_favor_startup, ik->fields(), _move_ro); |
| |
| mark_and_move_for_policy(OP_favor_runtime, ik->secondary_supers(), _move_ro); |
| mark_and_move_for_policy(OP_favor_runtime, ik->method_ordering(), _move_ro); |
| mark_and_move_for_policy(OP_favor_runtime, ik->class_annotations(), _move_ro); |
| mark_and_move_for_policy(OP_favor_runtime, ik->fields_annotations(), _move_ro); |
| mark_and_move_for_policy(OP_favor_runtime, ik->methods_annotations(), _move_ro); |
| mark_and_move_for_policy(OP_favor_runtime, ik->methods_parameter_annotations(), _move_ro); |
| mark_and_move_for_policy(OP_favor_runtime, ik->methods_default_annotations(), _move_ro); |
| mark_and_move_for_policy(OP_favor_runtime, ik->inner_classes(), _move_ro); |
| mark_and_move_for_policy(OP_favor_runtime, ik->secondary_supers(), _move_ro); |
| } |
| } |
| }; |
| |
| class MarkAndMoveOrderedReadWrite: public ObjectClosure { |
| private: |
| MoveMarkedObjects *_move_rw; |
| |
| public: |
| MarkAndMoveOrderedReadWrite(MoveMarkedObjects *move_rw) : _move_rw(move_rw) {} |
| |
| void do_object(oop obj) { |
| if (obj->is_klass() && obj->blueprint()->oop_is_instanceKlass()) { |
| instanceKlass* ik = instanceKlass::cast((klassOop)obj); |
| int i; |
| |
| mark_and_move_for_policy(OP_favor_startup, ik->as_klassOop(), _move_rw); |
| |
| if (ik->super() != NULL) { |
| do_object(ik->super()); |
| } |
| |
| objArrayOop interfaces = ik->local_interfaces(); |
| for(i = 0; i < interfaces->length(); i++) { |
| klassOop k = klassOop(interfaces->obj_at(i)); |
| mark_and_move_for_policy(OP_favor_startup, k, _move_rw); |
| do_object(k); |
| } |
| |
| objArrayOop methods = ik->methods(); |
| mark_and_move_for_policy(OP_favor_startup, methods, _move_rw); |
| for(i = 0; i < methods->length(); i++) { |
| methodOop m = methodOop(methods->obj_at(i)); |
| mark_and_move_for_policy(OP_favor_startup, m, _move_rw); |
| mark_and_move_for_policy(OP_favor_startup, ik->constants(), _move_rw); // idempotent |
| mark_and_move_for_policy(OP_balanced, ik->constants()->cache(), _move_rw); // idempotent |
| mark_and_move_for_policy(OP_balanced, ik->constants()->tags(), _move_rw); // idempotent |
| } |
| |
| mark_and_move_for_policy(OP_favor_startup, ik->as_klassOop()->klass(), _move_rw); |
| mark_and_move_for_policy(OP_favor_startup, ik->constants()->klass(), _move_rw); |
| |
| // Although Java mirrors are marked in MarkReadWriteObjects, |
| // apparently they were never moved into shared spaces since |
| // MoveMarkedObjects skips marked instance oops. This may |
| // be a bug in the original implementation or simply the vestige |
| // of an abandoned experiment. Nevertheless we leave a hint |
| // here in case this capability is ever correctly implemented. |
| // |
| // mark_and_move_for_policy(OP_favor_runtime, ik->java_mirror(), _move_rw); |
| } |
| } |
| |
| }; |
| |
| // Adjust references in oops to refer to shared spaces. |
| |
| class ResolveForwardingClosure: public OopClosure { |
| public: |
| void do_oop(oop* p) { |
| oop obj = *p; |
| if (!obj->is_shared()) { |
| if (obj != NULL) { |
| oop f = obj->forwardee(); |
| guarantee(f->is_shared(), "Oop doesn't refer to shared space."); |
| *p = f; |
| } |
| } |
| } |
| void do_oop(narrowOop* pobj) { ShouldNotReachHere(); } |
| }; |
| |
| |
| // The methods array must be reordered by Symbol* address. |
| // (See classFileParser.cpp where methods in a class are originally |
| // sorted). The addresses of symbols have been changed as a result |
| // of moving to the shared space. |
| |
| class SortMethodsClosure: public ObjectClosure { |
| public: |
| void do_object(oop obj) { |
| if (obj->blueprint()->oop_is_instanceKlass()) { |
| instanceKlass* ik = instanceKlass::cast((klassOop)obj); |
| methodOopDesc::sort_methods(ik->methods(), |
| ik->methods_annotations(), |
| ik->methods_parameter_annotations(), |
| ik->methods_default_annotations(), |
| true /* idempotent, slow */); |
| } |
| } |
| }; |
| |
| // Vtable and Itable indices are calculated based on methods array |
| // order (see klassItable::compute_itable_index()). Must reinitialize |
| // after ALL methods of ALL classes have been reordered. |
| // We assume that since checkconstraints is false, this method |
| // cannot throw an exception. An exception here would be |
| // problematic since this is the VMThread, not a JavaThread. |
| |
| class ReinitializeTables: public ObjectClosure { |
| private: |
| Thread* _thread; |
| |
| public: |
| ReinitializeTables(Thread* thread) : _thread(thread) {} |
| |
| // Initialize super vtable first, check if already initialized to avoid |
| // quadradic behavior. The vtable is cleared in remove_unshareable_info. |
| void reinitialize_vtables(klassOop k) { |
| if (k->blueprint()->oop_is_instanceKlass()) { |
| instanceKlass* ik = instanceKlass::cast(k); |
| if (ik->vtable()->is_initialized()) return; |
| if (ik->super() != NULL) { |
| reinitialize_vtables(ik->super()); |
| } |
| ik->vtable()->initialize_vtable(false, _thread); |
| } |
| } |
| |
| void do_object(oop obj) { |
| if (obj->blueprint()->oop_is_instanceKlass()) { |
| instanceKlass* ik = instanceKlass::cast((klassOop)obj); |
| ResourceMark rm(_thread); |
| ik->itable()->initialize_itable(false, _thread); |
| reinitialize_vtables((klassOop)obj); |
| #ifdef ASSERT |
| ik->vtable()->verify(tty, true); |
| #endif // ASSERT |
| } else if (obj->blueprint()->oop_is_arrayKlass()) { |
| // The vtable for array klasses are that of its super class, |
| // ie. java.lang.Object. |
| arrayKlass* ak = arrayKlass::cast((klassOop)obj); |
| if (ak->vtable()->is_initialized()) return; |
| ak->vtable()->initialize_vtable(false, _thread); |
| } |
| } |
| }; |
| |
| |
| // Adjust references in oops to refer to shared spaces. |
| |
| class PatchOopsClosure: public ObjectClosure { |
| private: |
| Thread* _thread; |
| ResolveForwardingClosure resolve; |
| |
| public: |
| PatchOopsClosure(Thread* thread) : _thread(thread) {} |
| |
| void do_object(oop obj) { |
| obj->oop_iterate_header(&resolve); |
| obj->oop_iterate(&resolve); |
| |
| assert(obj->klass()->is_shared(), "Klass not pointing into shared space."); |
| |
| // If the object is a Java object or class which might (in the |
| // future) contain a reference to a young gen object, add it to the |
| // list. |
| |
| if (obj->is_klass() || obj->is_instance()) { |
| if (obj->is_klass() || |
| obj->is_a(SystemDictionary::Class_klass()) || |
| obj->is_a(SystemDictionary::Throwable_klass())) { |
| // Do nothing |
| } |
| else if (obj->is_a(SystemDictionary::String_klass())) { |
| // immutable objects. |
| } else { |
| // someone added an object we hadn't accounted for. |
| ShouldNotReachHere(); |
| } |
| } |
| } |
| }; |
| |
| |
| // Empty the young and old generations. |
| |
| class ClearSpaceClosure : public SpaceClosure { |
| public: |
| void do_space(Space* s) { |
| s->clear(SpaceDecorator::Mangle); |
| } |
| }; |
| |
| |
| // Closure for serializing initialization data out to a data area to be |
| // written to the shared file. |
| |
| class WriteClosure : public SerializeOopClosure { |
| private: |
| oop* top; |
| char* end; |
| |
| inline void check_space() { |
| if ((char*)top + sizeof(oop) > end) { |
| report_out_of_shared_space(SharedMiscData); |
| } |
| } |
| |
| |
| public: |
| WriteClosure(char* md_top, char* md_end) { |
| top = (oop*)md_top; |
| end = md_end; |
| } |
| |
| char* get_top() { return (char*)top; } |
| |
| void do_oop(oop* p) { |
| check_space(); |
| oop obj = *p; |
| assert(obj->is_oop_or_null(), "invalid oop"); |
| assert(obj == NULL || obj->is_shared(), |
| "Oop in shared space not pointing into shared space."); |
| *top = obj; |
| ++top; |
| } |
| |
| void do_oop(narrowOop* pobj) { ShouldNotReachHere(); } |
| |
| void do_int(int* p) { |
| check_space(); |
| *top = (oop)(intptr_t)*p; |
| ++top; |
| } |
| |
| void do_size_t(size_t* p) { |
| check_space(); |
| *top = (oop)(intptr_t)*p; |
| ++top; |
| } |
| |
| void do_ptr(void** p) { |
| check_space(); |
| *top = (oop)*p; |
| ++top; |
| } |
| |
| void do_ptr(HeapWord** p) { do_ptr((void **) p); } |
| |
| void do_tag(int tag) { |
| check_space(); |
| *top = (oop)(intptr_t)tag; |
| ++top; |
| } |
| |
| void do_region(u_char* start, size_t size) { |
| if ((char*)top + size > end) { |
| report_out_of_shared_space(SharedMiscData); |
| } |
| assert((intptr_t)start % sizeof(oop) == 0, "bad alignment"); |
| assert(size % sizeof(oop) == 0, "bad size"); |
| do_tag((int)size); |
| while (size > 0) { |
| *top = *(oop*)start; |
| ++top; |
| start += sizeof(oop); |
| size -= sizeof(oop); |
| } |
| } |
| |
| bool reading() const { return false; } |
| }; |
| |
| |
| class ResolveConstantPoolsClosure : public ObjectClosure { |
| private: |
| TRAPS; |
| public: |
| ResolveConstantPoolsClosure(Thread *t) { |
| __the_thread__ = t; |
| } |
| void do_object(oop obj) { |
| if (obj->is_constantPool()) { |
| constantPoolOop cpool = (constantPoolOop)obj; |
| int unresolved = cpool->pre_resolve_shared_klasses(THREAD); |
| } |
| } |
| }; |
| |
| |
| // Print a summary of the contents of the read/write spaces to help |
| // identify objects which might be able to be made read-only. At this |
| // point, the objects have been written, and we can trash them as |
| // needed. |
| |
| static void print_contents() { |
| if (PrintSharedSpaces) { |
| GenCollectedHeap* gch = GenCollectedHeap::heap(); |
| CompactingPermGenGen* gen = (CompactingPermGenGen*)gch->perm_gen(); |
| |
| // High level summary of the read-only space: |
| |
| ClassifyObjectClosure coc; |
| tty->cr(); tty->print_cr("ReadOnly space:"); |
| gen->ro_space()->object_iterate(&coc); |
| coc.print(); |
| |
| // High level summary of the read-write space: |
| |
| coc.reset(); |
| tty->cr(); tty->print_cr("ReadWrite space:"); |
| gen->rw_space()->object_iterate(&coc); |
| coc.print(); |
| |
| // Reset counters |
| |
| ClearAllocCountClosure cacc; |
| gen->ro_space()->object_iterate(&cacc); |
| gen->rw_space()->object_iterate(&cacc); |
| coc.reset(); |
| |
| // Lower level summary of the read-only space: |
| |
| gen->ro_space()->object_iterate(&coc); |
| tty->cr(); tty->print_cr("ReadOnly space:"); |
| ClassifyInstanceKlassClosure cikc; |
| gen->rw_space()->object_iterate(&cikc); |
| cikc.print(); |
| |
| // Reset counters |
| |
| gen->ro_space()->object_iterate(&cacc); |
| gen->rw_space()->object_iterate(&cacc); |
| coc.reset(); |
| |
| // Lower level summary of the read-write space: |
| |
| gen->rw_space()->object_iterate(&coc); |
| cikc.reset(); |
| tty->cr(); tty->print_cr("ReadWrite space:"); |
| gen->rw_space()->object_iterate(&cikc); |
| cikc.print(); |
| } |
| } |
| |
| |
| // Patch C++ vtable pointer in klass oops. |
| |
| // Klass objects contain references to c++ vtables in the JVM library. |
| // Fix them to point to our constructed vtables. However, don't iterate |
| // across the space while doing this, as that causes the vtables to be |
| // patched, undoing our useful work. Instead, iterate to make a list, |
| // then use the list to do the fixing. |
| // |
| // Our constructed vtables: |
| // Dump time: |
| // 1. init_self_patching_vtbl_list: table of pointers to current virtual method addrs |
| // 2. generate_vtable_methods: create jump table, appended to above vtbl_list |
| // 3. PatchKlassVtables: for Klass list, patch the vtable entry to point to jump table |
| // rather than to current vtbl |
| // Table layout: NOTE FIXED SIZE |
| // 1. vtbl pointers |
| // 2. #Klass X #virtual methods per Klass |
| // 1 entry for each, in the order: |
| // Klass1:method1 entry, Klass1:method2 entry, ... Klass1:method<num_virtuals> entry |
| // Klass2:method1 entry, Klass2:method2 entry, ... Klass2:method<num_virtuals> entry |
| // ... |
| // Klass<vtbl_list_size>:method1 entry, Klass<vtbl_list_size>:method2 entry, |
| // ... Klass<vtbl_list_size>:method<num_virtuals> entry |
| // Sample entry: (Sparc): |
| // save(sp, -256, sp) |
| // ba,pt common_code |
| // mov XXX, %L0 %L0 gets: Klass index <<8 + method index (note: max method index 255) |
| // |
| // Restore time: |
| // 1. initialize_oops: reserve space for table |
| // 2. init_self_patching_vtbl_list: update pointers to NEW virtual method addrs in text |
| // |
| // Execution time: |
| // First virtual method call for any object of these Klass types: |
| // 1. object->klass->klass_part |
| // 2. vtable entry for that klass_part points to the jump table entries |
| // 3. branches to common_code with %O0/klass_part, %L0: Klass index <<8 + method index |
| // 4. common_code: |
| // Get address of new vtbl pointer for this Klass from updated table |
| // Update new vtbl pointer in the Klass: future virtual calls go direct |
| // Jump to method, using new vtbl pointer and method index |
| |
| class PatchKlassVtables: public ObjectClosure { |
| private: |
| GrowableArray<klassOop>* _klass_objects; |
| |
| public: |
| PatchKlassVtables() { |
| _klass_objects = new GrowableArray<klassOop>(); |
| } |
| |
| void do_object(oop obj) { |
| if (obj->is_klass()) { |
| _klass_objects->append(klassOop(obj)); |
| } |
| } |
| |
| void patch(void** vtbl_list, void* new_vtable_start) { |
| int n = _klass_objects->length(); |
| for (int i = 0; i < n; i++) { |
| klassOop obj = (klassOop)_klass_objects->at(i); |
| Klass* k = obj->klass_part(); |
| *(void**)k = CompactingPermGenGen::find_matching_vtbl_ptr( |
| vtbl_list, new_vtable_start, k); |
| } |
| } |
| }; |
| |
| // Walk through all symbols and patch their vtable pointers. |
| // Note that symbols have vtable pointers only in non-product builds |
| // (see allocation.hpp). |
| |
| #ifndef PRODUCT |
| class PatchSymbolVtables: public SymbolClosure { |
| private: |
| void* _new_vtbl_ptr; |
| |
| public: |
| PatchSymbolVtables(void** vtbl_list, void* new_vtable_start) { |
| Symbol s; |
| _new_vtbl_ptr = CompactingPermGenGen::find_matching_vtbl_ptr( |
| vtbl_list, new_vtable_start, &s); |
| } |
| |
| void do_symbol(Symbol** p) { |
| Symbol* sym = load_symbol(p); |
| *(void**)sym = _new_vtbl_ptr; |
| } |
| }; |
| #endif |
| |
| |
| // Populate the shared space. |
| |
| class VM_PopulateDumpSharedSpace: public VM_Operation { |
| private: |
| GrowableArray<oop> *_class_promote_order; |
| OffsetTableContigSpace* _ro_space; |
| OffsetTableContigSpace* _rw_space; |
| VirtualSpace* _md_vs; |
| VirtualSpace* _mc_vs; |
| |
| public: |
| VM_PopulateDumpSharedSpace(GrowableArray<oop> *class_promote_order, |
| OffsetTableContigSpace* ro_space, |
| OffsetTableContigSpace* rw_space, |
| VirtualSpace* md_vs, VirtualSpace* mc_vs) { |
| _class_promote_order = class_promote_order; |
| _ro_space = ro_space; |
| _rw_space = rw_space; |
| _md_vs = md_vs; |
| _mc_vs = mc_vs; |
| } |
| |
| VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; } |
| void doit() { |
| Thread* THREAD = VMThread::vm_thread(); |
| NOT_PRODUCT(SystemDictionary::verify();) |
| // The following guarantee is meant to ensure that no loader constraints |
| // exist yet, since the constraints table is not shared. This becomes |
| // more important now that we don't re-initialize vtables/itables for |
| // shared classes at runtime, where constraints were previously created. |
| guarantee(SystemDictionary::constraints()->number_of_entries() == 0, |
| "loader constraints are not saved"); |
| // Revisit and implement this if we prelink method handle call sites: |
| guarantee(SystemDictionary::invoke_method_table() == NULL || |
| SystemDictionary::invoke_method_table()->number_of_entries() == 0, |
| "invoke method table is not saved"); |
| GenCollectedHeap* gch = GenCollectedHeap::heap(); |
| |
| // At this point, many classes have been loaded. |
| |
| // Update all the fingerprints in the shared methods. |
| |
| tty->print("Calculating fingerprints ... "); |
| FingerprintMethodsClosure fpmc; |
| gch->object_iterate(&fpmc); |
| tty->print_cr("done. "); |
| |
| // Remove all references outside the heap. |
| |
| tty->print("Removing unshareable information ... "); |
| RemoveUnshareableInfoClosure ruic; |
| gch->object_iterate(&ruic); |
| tty->print_cr("done. "); |
| |
| // Move the objects in three passes. |
| |
| MarkObjectsOopClosure mark_all; |
| MarkCommonReadOnly mark_common_ro; |
| MarkStringValues mark_string_values; |
| MarkReadWriteObjects mark_rw; |
| MarkStringObjects mark_strings; |
| MoveMarkedObjects move_ro(_ro_space, true); |
| MoveMarkedObjects move_rw(_rw_space, false); |
| |
| // The SharedOptimizeColdStart VM option governs the new layout |
| // algorithm for promoting classes into the shared archive. |
| // The general idea is to minimize cold start time by laying |
| // out the objects in the order they are accessed at startup time. |
| // By doing this we are trying to eliminate out-of-order accesses |
| // in the shared archive. This benefits cold startup time by making |
| // disk reads as sequential as possible during class loading and |
| // bootstrapping activities. There may also be a small secondary |
| // effect of better "packing" of more commonly used data on a smaller |
| // number of pages, although no direct benefit has been measured from |
| // this effect. |
| // |
| // At the class level of granularity, the promotion order is dictated |
| // by the classlist file whose generation is discussed elsewhere. |
| // |
| // At smaller granularity, optimal ordering was determined by an |
| // offline analysis of object access order in the shared archive. |
| // The dbx watchpoint facility, combined with SA post-processing, |
| // was used to observe common access patterns primarily during |
| // classloading. This information was used to craft the promotion |
| // order seen in the following closures. |
| // |
| // The observed access order is mostly governed by what happens |
| // in SystemDictionary::load_shared_class(). NOTE WELL - care |
| // should be taken when making changes to this method, because it |
| // may invalidate assumptions made about access order! |
| // |
| // (Ideally, there would be a better way to manage changes to |
| // the access order. Unfortunately a generic in-VM solution for |
| // dynamically observing access order and optimizing shared |
| // archive layout is pretty difficult. We go with the static |
| // analysis because the code is fairly mature at this point |
| // and we're betting that the access order won't change much.) |
| |
| MarkAndMoveOrderedReadOnly mark_and_move_ordered_ro(&move_ro); |
| MarkAndMoveOrderedReadWrite mark_and_move_ordered_rw(&move_rw); |
| |
| // Set up the share data and shared code segments. |
| |
| char* md_top = _md_vs->low(); |
| char* md_end = _md_vs->high(); |
| char* mc_top = _mc_vs->low(); |
| char* mc_end = _mc_vs->high(); |
| |
| // Reserve space for the list of klassOops whose vtables are used |
| // for patching others as needed. |
| |
| void** vtbl_list = (void**)md_top; |
| int vtbl_list_size = CompactingPermGenGen::vtbl_list_size; |
| Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size); |
| |
| md_top += vtbl_list_size * sizeof(void*); |
| void* vtable = md_top; |
| |
| // Reserve space for a new dummy vtable for klass objects in the |
| // heap. Generate self-patching vtable entries. |
| |
| CompactingPermGenGen::generate_vtable_methods(vtbl_list, |
| &vtable, |
| &md_top, md_end, |
| &mc_top, mc_end); |
| |
| // Reserve space for the total size and the number of stored symbols. |
| |
| md_top += sizeof(intptr_t) * 2; |
| |
| MoveSymbols move_symbols(md_top, md_end); |
| CommonSymbolsClosure traverse_common_symbols(&move_symbols); |
| |
| // Phase 1a: remove symbols with _refcount == 0 |
| |
| SymbolTable::unlink(); |
| |
| // Phase 1b: move commonly used symbols referenced by oop fields. |
| |
| tty->print("Moving common symbols to metadata section at " PTR_FORMAT " ... ", |
| move_symbols.get_top()); |
| gch->object_iterate(&traverse_common_symbols); |
| tty->print_cr("done. "); |
| |
| // Phase 1c: move known names and signatures. |
| |
| tty->print("Moving vmSymbols to metadata section at " PTR_FORMAT " ... ", |
| move_symbols.get_top()); |
| vmSymbols::symbols_do(&move_symbols); |
| tty->print_cr("done. "); |
| |
| // Phase 1d: move the remaining symbols by scanning the whole SymbolTable. |
| |
| void* extra_symbols = move_symbols.get_top(); |
| tty->print("Moving the remaining symbols to metadata section at " PTR_FORMAT " ... ", |
| move_symbols.get_top()); |
| SymbolTable::symbols_do(&move_symbols); |
| tty->print_cr("done. "); |
| |
| // Record the total length of all symbols at the beginning of the block. |
| ((intptr_t*)md_top)[-2] = move_symbols.get_top() - md_top; |
| ((intptr_t*)md_top)[-1] = move_symbols.count(); |
| tty->print_cr("Moved %d symbols, %d bytes.", |
| move_symbols.count(), move_symbols.get_top() - md_top); |
| // Advance the pointer to the end of symbol store. |
| md_top = move_symbols.get_top(); |
| |
| |
| // Phase 2: move commonly used read-only objects to the read-only space. |
| |
| if (SharedOptimizeColdStart) { |
| tty->print("Moving pre-ordered read-only objects to shared space at " PTR_FORMAT " ... ", |
| _ro_space->top()); |
| for (int i = 0; i < _class_promote_order->length(); i++) { |
| oop obj = _class_promote_order->at(i); |
| mark_and_move_ordered_ro.do_object(obj); |
| } |
| tty->print_cr("done. "); |
| } |
| |
| tty->print("Moving read-only objects to shared space at " PTR_FORMAT " ... ", |
| _ro_space->top()); |
| gch->object_iterate(&mark_common_ro); |
| gch->object_iterate(&move_ro); |
| tty->print_cr("done. "); |
| |
| // Phase 3: move String character arrays to the read-only space. |
| |
| tty->print("Moving string char arrays to shared space at " PTR_FORMAT " ... ", |
| _ro_space->top()); |
| gch->object_iterate(&mark_string_values); |
| gch->object_iterate(&move_ro); |
| tty->print_cr("done. "); |
| |
| // Phase 4: move read-write objects to the read-write space, except |
| // Strings. |
| |
| if (SharedOptimizeColdStart) { |
| tty->print("Moving pre-ordered read-write objects to shared space at " PTR_FORMAT " ... ", |
| _rw_space->top()); |
| for (int i = 0; i < _class_promote_order->length(); i++) { |
| oop obj = _class_promote_order->at(i); |
| mark_and_move_ordered_rw.do_object(obj); |
| } |
| tty->print_cr("done. "); |
| } |
| tty->print("Moving read-write objects to shared space at " PTR_FORMAT " ... ", |
| _rw_space->top()); |
| Universe::oops_do(&mark_all, true); |
| SystemDictionary::oops_do(&mark_all); |
| oop tmp = Universe::arithmetic_exception_instance(); |
| mark_object(java_lang_Throwable::message(tmp)); |
| gch->object_iterate(&mark_rw); |
| gch->object_iterate(&move_rw); |
| tty->print_cr("done. "); |
| |
| // Phase 5: move String objects to the read-write space. |
| |
| tty->print("Moving String objects to shared space at " PTR_FORMAT " ... ", |
| _rw_space->top()); |
| StringTable::oops_do(&mark_all); |
| gch->object_iterate(&mark_strings); |
| gch->object_iterate(&move_rw); |
| tty->print_cr("done. "); |
| tty->print_cr("Read-write space ends at " PTR_FORMAT ", %d bytes.", |
| _rw_space->top(), _rw_space->used()); |
| |
| #ifdef DEBUG |
| // Check: scan for objects which were not moved. |
| |
| CheckRemainingObjects check_objects; |
| gch->object_iterate(&check_objects); |
| check_objects.status(); |
| #endif |
| |
| // Resolve forwarding in objects and saved C++ structures |
| tty->print("Updating references to shared objects ... "); |
| ResolveForwardingClosure resolve; |
| Universe::oops_do(&resolve); |
| SystemDictionary::oops_do(&resolve); |
| StringTable::oops_do(&resolve); |
| |
| // Fix (forward) all of the references in these shared objects (which |
| // are required to point ONLY to objects in the shared spaces). |
| // Also, create a list of all objects which might later contain a |
| // reference to a younger generation object. |
| |
| CompactingPermGenGen* gen = (CompactingPermGenGen*)gch->perm_gen(); |
| PatchOopsClosure patch(THREAD); |
| gen->ro_space()->object_iterate(&patch); |
| gen->rw_space()->object_iterate(&patch); |
| |
| // Previously method sorting was done concurrently with forwarding |
| // pointer resolution in the shared spaces. This imposed an ordering |
| // restriction in that methods were required to be promoted/patched |
| // before their holder classes. (Because constant pool pointers in |
| // methodKlasses are required to be resolved before their holder class |
| // is visited for sorting, otherwise methods are sorted by incorrect, |
| // pre-forwarding addresses.) |
| // |
| // Now, we reorder methods as a separate step after ALL forwarding |
| // pointer resolution, so that methods can be promoted in any order |
| // with respect to their holder classes. |
| |
| SortMethodsClosure sort; |
| gen->ro_space()->object_iterate(&sort); |
| gen->rw_space()->object_iterate(&sort); |
| |
| ReinitializeTables reinit_tables(THREAD); |
| gen->ro_space()->object_iterate(&reinit_tables); |
| gen->rw_space()->object_iterate(&reinit_tables); |
| tty->print_cr("done. "); |
| tty->cr(); |
| |
| // Reorder the system dictionary. (Moving the symbols opps affects |
| // how the hash table indices are calculated.) |
| |
| SystemDictionary::reorder_dictionary(); |
| |
| // Empty the non-shared heap (because most of the objects were |
| // copied out, and the remainder cannot be considered valid oops). |
| |
| ClearSpaceClosure csc; |
| for (int i = 0; i < gch->n_gens(); ++i) { |
| gch->get_gen(i)->space_iterate(&csc); |
| } |
| csc.do_space(gen->the_space()); |
| NOT_PRODUCT(SystemDictionary::verify();) |
| |
| // Copy the String table, the symbol table, and the system |
| // dictionary to the shared space in usable form. Copy the hastable |
| // buckets first [read-write], then copy the linked lists of entries |
| // [read-only]. |
| |
| SymbolTable::reverse(extra_symbols); |
| NOT_PRODUCT(SymbolTable::verify()); |
| SymbolTable::copy_buckets(&md_top, md_end); |
| |
| StringTable::reverse(); |
| NOT_PRODUCT(StringTable::verify()); |
| StringTable::copy_buckets(&md_top, md_end); |
| |
| SystemDictionary::reverse(); |
| SystemDictionary::copy_buckets(&md_top, md_end); |
| |
| ClassLoader::verify(); |
| ClassLoader::copy_package_info_buckets(&md_top, md_end); |
| ClassLoader::verify(); |
| |
| SymbolTable::copy_table(&md_top, md_end); |
| StringTable::copy_table(&md_top, md_end); |
| SystemDictionary::copy_table(&md_top, md_end); |
| ClassLoader::verify(); |
| ClassLoader::copy_package_info_table(&md_top, md_end); |
| ClassLoader::verify(); |
| |
| // Print debug data. |
| |
| if (PrintSharedSpaces) { |
| const char* fmt = "%s space: " PTR_FORMAT " out of " PTR_FORMAT " bytes allocated at " PTR_FORMAT "."; |
| tty->print_cr(fmt, "ro", _ro_space->used(), _ro_space->capacity(), |
| _ro_space->bottom()); |
| tty->print_cr(fmt, "rw", _rw_space->used(), _rw_space->capacity(), |
| _rw_space->bottom()); |
| } |
| |
| // Write the oop data to the output array. |
| |
| WriteClosure wc(md_top, md_end); |
| CompactingPermGenGen::serialize_oops(&wc); |
| md_top = wc.get_top(); |
| |
| // Update the vtable pointers in all of the Klass objects in the |
| // heap. They should point to newly generated vtable. |
| |
| PatchKlassVtables pkvt; |
| _rw_space->object_iterate(&pkvt); |
| pkvt.patch(vtbl_list, vtable); |
| |
| #ifndef PRODUCT |
| // Update the vtable pointers in all symbols, |
| // but only in non-product builds where symbols DO have virtual methods. |
| PatchSymbolVtables psvt(vtbl_list, vtable); |
| SymbolTable::symbols_do(&psvt); |
| #endif |
| |
| char* saved_vtbl = (char*)malloc(vtbl_list_size * sizeof(void*)); |
| memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*)); |
| memset(vtbl_list, 0, vtbl_list_size * sizeof(void*)); |
| |
| // Create and write the archive file that maps the shared spaces. |
| |
| FileMapInfo* mapinfo = new FileMapInfo(); |
| mapinfo->populate_header(gch->gen_policy()->max_alignment()); |
| |
| // Pass 1 - update file offsets in header. |
| mapinfo->write_header(); |
| mapinfo->write_space(CompactingPermGenGen::ro, _ro_space, true); |
| _ro_space->set_saved_mark(); |
| mapinfo->write_space(CompactingPermGenGen::rw, _rw_space, false); |
| _rw_space->set_saved_mark(); |
| mapinfo->write_region(CompactingPermGenGen::md, _md_vs->low(), |
| pointer_delta(md_top, _md_vs->low(), sizeof(char)), |
| SharedMiscDataSize, |
| false, false); |
| mapinfo->write_region(CompactingPermGenGen::mc, _mc_vs->low(), |
| pointer_delta(mc_top, _mc_vs->low(), sizeof(char)), |
| SharedMiscCodeSize, |
| true, true); |
| |
| // Pass 2 - write data. |
| mapinfo->open_for_write(); |
| mapinfo->write_header(); |
| mapinfo->write_space(CompactingPermGenGen::ro, _ro_space, true); |
| mapinfo->write_space(CompactingPermGenGen::rw, _rw_space, false); |
| mapinfo->write_region(CompactingPermGenGen::md, _md_vs->low(), |
| pointer_delta(md_top, _md_vs->low(), sizeof(char)), |
| SharedMiscDataSize, |
| false, false); |
| mapinfo->write_region(CompactingPermGenGen::mc, _mc_vs->low(), |
| pointer_delta(mc_top, _mc_vs->low(), sizeof(char)), |
| SharedMiscCodeSize, |
| true, true); |
| mapinfo->close(); |
| |
| // Summarize heap. |
| memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*)); |
| print_contents(); |
| } |
| }; // class VM_PopulateDumpSharedSpace |
| |
| |
| // Populate the shared spaces and dump to a file. |
| |
| jint CompactingPermGenGen::dump_shared(GrowableArray<oop>* class_promote_order, TRAPS) { |
| GenCollectedHeap* gch = GenCollectedHeap::heap(); |
| |
| // Calculate hash values for all of the (interned) strings to avoid |
| // writes to shared pages in the future. |
| |
| tty->print("Calculating hash values for String objects .. "); |
| StringHashCodeClosure shcc(THREAD); |
| StringTable::oops_do(&shcc); |
| tty->print_cr("done. "); |
| |
| CompactingPermGenGen* gen = (CompactingPermGenGen*)gch->perm_gen(); |
| VM_PopulateDumpSharedSpace op(class_promote_order, |
| gen->ro_space(), gen->rw_space(), |
| gen->md_space(), gen->mc_space()); |
| VMThread::execute(&op); |
| return JNI_OK; |
| } |
| |
| void* CompactingPermGenGen::find_matching_vtbl_ptr(void** vtbl_list, |
| void* new_vtable_start, |
| void* obj) { |
| void* old_vtbl_ptr = *(void**)obj; |
| for (int i = 0; i < vtbl_list_size; i++) { |
| if (vtbl_list[i] == old_vtbl_ptr) { |
| return (void**)new_vtable_start + i * num_virtuals; |
| } |
| } |
| ShouldNotReachHere(); |
| return NULL; |
| } |
| |
| |
| class LinkClassesClosure : public ObjectClosure { |
| private: |
| Thread* THREAD; |
| |
| public: |
| LinkClassesClosure(Thread* thread) : THREAD(thread) {} |
| |
| void do_object(oop obj) { |
| if (obj->is_klass()) { |
| Klass* k = Klass::cast((klassOop) obj); |
| if (k->oop_is_instance()) { |
| instanceKlass* ik = (instanceKlass*) k; |
| // Link the class to cause the bytecodes to be rewritten and the |
| // cpcache to be created. |
| if (ik->init_state() < instanceKlass::linked) { |
| ik->link_class(THREAD); |
| guarantee(!HAS_PENDING_EXCEPTION, "exception in class rewriting"); |
| } |
| |
| // Create String objects from string initializer symbols. |
| ik->constants()->resolve_string_constants(THREAD); |
| guarantee(!HAS_PENDING_EXCEPTION, "exception resolving string constants"); |
| } |
| } |
| } |
| }; |
| |
| |
| // Support for a simple checksum of the contents of the class list |
| // file to prevent trivial tampering. The algorithm matches that in |
| // the MakeClassList program used by the J2SE build process. |
| #define JSUM_SEED ((jlong)CONST64(0xcafebabebabecafe)) |
| static jlong |
| jsum(jlong start, const char *buf, const int len) |
| { |
| jlong h = start; |
| char *p = (char *)buf, *e = p + len; |
| while (p < e) { |
| char c = *p++; |
| if (c <= ' ') { |
| /* Skip spaces and control characters */ |
| continue; |
| } |
| h = 31 * h + c; |
| } |
| return h; |
| } |
| |
| |
| |
| |
| |
| // Preload classes from a list, populate the shared spaces and dump to a |
| // file. |
| |
| void GenCollectedHeap::preload_and_dump(TRAPS) { |
| TraceTime timer("Dump Shared Spaces", TraceStartupTime); |
| ResourceMark rm; |
| |
| // Preload classes to be shared. |
| // Should use some os:: method rather than fopen() here. aB. |
| // Construct the path to the class list (in jre/lib) |
| // Walk up two directories from the location of the VM and |
| // optionally tack on "lib" (depending on platform) |
| char class_list_path[JVM_MAXPATHLEN]; |
| os::jvm_path(class_list_path, sizeof(class_list_path)); |
| for (int i = 0; i < 3; i++) { |
| char *end = strrchr(class_list_path, *os::file_separator()); |
| if (end != NULL) *end = '\0'; |
| } |
| int class_list_path_len = (int)strlen(class_list_path); |
| if (class_list_path_len >= 3) { |
| if (strcmp(class_list_path + class_list_path_len - 3, "lib") != 0) { |
| strcat(class_list_path, os::file_separator()); |
| strcat(class_list_path, "lib"); |
| } |
| } |
| strcat(class_list_path, os::file_separator()); |
| strcat(class_list_path, "classlist"); |
| |
| FILE* file = fopen(class_list_path, "r"); |
| if (file != NULL) { |
| jlong computed_jsum = JSUM_SEED; |
| jlong file_jsum = 0; |
| |
| char class_name[256]; |
| int class_count = 0; |
| GenCollectedHeap* gch = GenCollectedHeap::heap(); |
| gch->_preloading_shared_classes = true; |
| GrowableArray<oop>* class_promote_order = new GrowableArray<oop>(); |
| |
| // Preload (and intern) strings which will be used later. |
| |
| StringTable::intern("main", THREAD); |
| StringTable::intern("([Ljava/lang/String;)V", THREAD); |
| StringTable::intern("Ljava/lang/Class;", THREAD); |
| |
| StringTable::intern("I", THREAD); // Needed for StringBuffer persistence? |
| StringTable::intern("Z", THREAD); // Needed for StringBuffer persistence? |
| |
| // sun.io.Converters |
| static const char obj_array_sig[] = "[[Ljava/lang/Object;"; |
| (void)SymbolTable::new_permanent_symbol(obj_array_sig, THREAD); |
| |
| // java.util.HashMap |
| static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;"; |
| (void)SymbolTable::new_permanent_symbol(map_entry_array_sig, THREAD); |
| |
| tty->print("Loading classes to share ... "); |
| while ((fgets(class_name, sizeof class_name, file)) != NULL) { |
| if (*class_name == '#') { |
| jint fsh, fsl; |
| if (sscanf(class_name, "# %8x%8x\n", &fsh, &fsl) == 2) { |
| file_jsum = ((jlong)(fsh) << 32) | (fsl & 0xffffffff); |
| } |
| |
| continue; |
| } |
| // Remove trailing newline |
| size_t name_len = strlen(class_name); |
| class_name[name_len-1] = '\0'; |
| |
| computed_jsum = jsum(computed_jsum, class_name, (const int)name_len - 1); |
| |
| // Got a class name - load it. |
| Symbol* class_name_symbol = SymbolTable::new_permanent_symbol(class_name, THREAD); |
| guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol."); |
| klassOop klass = SystemDictionary::resolve_or_null(class_name_symbol, |
| THREAD); |
| guarantee(!HAS_PENDING_EXCEPTION, "Exception resolving a class."); |
| if (klass != NULL) { |
| if (PrintSharedSpaces) { |
| tty->print_cr("Shared spaces preloaded: %s", class_name); |
| } |
| |
| |
| instanceKlass* ik = instanceKlass::cast(klass); |
| |
| // Should be class load order as per -XX:+TraceClassLoadingPreorder |
| class_promote_order->append(ik->as_klassOop()); |
| |
| // Link the class to cause the bytecodes to be rewritten and the |
| // cpcache to be created. The linking is done as soon as classes |
| // are loaded in order that the related data structures (klass, |
| // cpCache, Sting constants) are located together. |
| |
| if (ik->init_state() < instanceKlass::linked) { |
| ik->link_class(THREAD); |
| guarantee(!(HAS_PENDING_EXCEPTION), "exception in class rewriting"); |
| } |
| |
| // Create String objects from string initializer symbols. |
| |
| ik->constants()->resolve_string_constants(THREAD); |
| |
| class_count++; |
| } else { |
| if (PrintSharedSpaces) { |
| tty->cr(); |
| tty->print_cr(" Preload failed: %s", class_name); |
| } |
| } |
| file_jsum = 0; // Checksum must be on last line of file |
| } |
| if (computed_jsum != file_jsum) { |
| tty->cr(); |
| tty->print_cr("Preload failed: checksum of class list was incorrect."); |
| exit(1); |
| } |
| |
| tty->print_cr("done. "); |
| |
| if (PrintSharedSpaces) { |
| tty->print_cr("Shared spaces: preloaded %d classes", class_count); |
| } |
| |
| // Rewrite and unlink classes. |
| tty->print("Rewriting and unlinking classes ... "); |
| // Make heap parsable |
| ensure_parsability(false); // arg is actually don't care |
| |
| // Link any classes which got missed. (It's not quite clear why |
| // they got missed.) This iteration would be unsafe if we weren't |
| // single-threaded at this point; however we can't do it on the VM |
| // thread because it requires object allocation. |
| LinkClassesClosure lcc(Thread::current()); |
| object_iterate(&lcc); |
| ensure_parsability(false); // arg is actually don't care |
| tty->print_cr("done. "); |
| |
| // Create and dump the shared spaces. |
| jint err = CompactingPermGenGen::dump_shared(class_promote_order, THREAD); |
| if (err != JNI_OK) { |
| fatal("Dumping shared spaces failed."); |
| } |
| |
| } else { |
| char errmsg[JVM_MAXPATHLEN]; |
| os::lasterror(errmsg, JVM_MAXPATHLEN); |
| tty->print_cr("Loading classlist failed: %s", errmsg); |
| exit(1); |
| } |
| |
| // Since various initialization steps have been undone by this process, |
| // it is not reasonable to continue running a java process. |
| exit(0); |
| } |