| /* |
| * Copyright (c) 2018, 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.inline.hpp" |
| #include "classfile/vmSymbols.hpp" |
| #include "logging/log.hpp" |
| #include "logging/logMessage.hpp" |
| #include "logging/logStream.hpp" |
| #include "memory/heapShared.hpp" |
| #include "memory/iterator.inline.hpp" |
| #include "memory/metadataFactory.hpp" |
| #include "memory/metaspaceClosure.hpp" |
| #include "memory/metaspaceShared.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "oops/compressedOops.inline.hpp" |
| #include "oops/oop.inline.hpp" |
| |
| #if INCLUDE_CDS_JAVA_HEAP |
| KlassSubGraphInfo* HeapShared::_subgraph_info_list = NULL; |
| int HeapShared::_num_archived_subgraph_info_records = 0; |
| Array<ArchivedKlassSubGraphInfoRecord>* HeapShared::_archived_subgraph_info_records = NULL; |
| |
| // Currently there is only one class mirror (ArchivedModuleGraph) with archived |
| // sub-graphs. |
| KlassSubGraphInfo* HeapShared::find_subgraph_info(Klass* k) { |
| KlassSubGraphInfo* info = _subgraph_info_list; |
| while (info != NULL) { |
| if (info->klass() == k) { |
| return info; |
| } |
| info = info->next(); |
| } |
| return NULL; |
| } |
| |
| // Get the subgraph_info for Klass k. A new subgraph_info is created if |
| // there is no existing one for k. The subgraph_info records the relocated |
| // Klass* of the original k. |
| KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) { |
| Klass* relocated_k = MetaspaceShared::get_relocated_klass(k); |
| KlassSubGraphInfo* info = find_subgraph_info(relocated_k); |
| if (info != NULL) { |
| return info; |
| } |
| |
| info = new KlassSubGraphInfo(relocated_k, _subgraph_info_list); |
| _subgraph_info_list = info; |
| return info; |
| } |
| |
| int HeapShared::num_of_subgraph_infos() { |
| int num = 0; |
| KlassSubGraphInfo* info = _subgraph_info_list; |
| while (info != NULL) { |
| num ++; |
| info = info->next(); |
| } |
| return num; |
| } |
| |
| // Add an entry field to the current KlassSubGraphInfo. |
| void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) { |
| assert(DumpSharedSpaces, "dump time only"); |
| if (_subgraph_entry_fields == NULL) { |
| _subgraph_entry_fields = |
| new(ResourceObj::C_HEAP, mtClass) GrowableArray<juint>(10, true); |
| } |
| _subgraph_entry_fields->append((juint)static_field_offset); |
| _subgraph_entry_fields->append(CompressedOops::encode(v)); |
| } |
| |
| // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs. |
| // Only objects of boot classes can be included in sub-graph. |
| void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k, Klass *relocated_k) { |
| assert(DumpSharedSpaces, "dump time only"); |
| assert(relocated_k == MetaspaceShared::get_relocated_klass(orig_k), |
| "must be the relocated Klass in the shared space"); |
| |
| if (_subgraph_object_klasses == NULL) { |
| _subgraph_object_klasses = |
| new(ResourceObj::C_HEAP, mtClass) GrowableArray<Klass*>(50, true); |
| } |
| |
| assert(relocated_k->is_shared(), "must be a shared class"); |
| |
| if (_k == relocated_k) { |
| // Don't add the Klass containing the sub-graph to it's own klass |
| // initialization list. |
| return; |
| } |
| |
| if (relocated_k->is_instance_klass()) { |
| assert(InstanceKlass::cast(relocated_k)->is_shared_boot_class(), |
| "must be boot class"); |
| // SystemDictionary::xxx_klass() are not updated, need to check |
| // the original Klass* |
| if (orig_k == SystemDictionary::String_klass() || |
| orig_k == SystemDictionary::Object_klass()) { |
| // Initialized early during VM initialization. No need to be added |
| // to the sub-graph object class list. |
| return; |
| } |
| } else if (relocated_k->is_objArray_klass()) { |
| Klass* abk = ObjArrayKlass::cast(relocated_k)->bottom_klass(); |
| if (abk->is_instance_klass()) { |
| assert(InstanceKlass::cast(abk)->is_shared_boot_class(), |
| "must be boot class"); |
| } |
| if (relocated_k == Universe::objectArrayKlassObj()) { |
| // Initialized early during Universe::genesis. No need to be added |
| // to the list. |
| return; |
| } |
| } else { |
| assert(relocated_k->is_typeArray_klass(), "must be"); |
| // Primitive type arrays are created early during Universe::genesis. |
| return; |
| } |
| |
| _subgraph_object_klasses->append_if_missing(relocated_k); |
| } |
| |
| // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo. |
| void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) { |
| _k = info->klass(); |
| _next = NULL; |
| _entry_field_records = NULL; |
| _subgraph_klasses = NULL; |
| |
| // populate the entry fields |
| GrowableArray<juint>* entry_fields = info->subgraph_entry_fields(); |
| if (entry_fields != NULL) { |
| int num_entry_fields = entry_fields->length(); |
| assert(num_entry_fields % 2 == 0, "sanity"); |
| _entry_field_records = |
| MetaspaceShared::new_ro_array<juint>(num_entry_fields); |
| for (int i = 0 ; i < num_entry_fields; i++) { |
| _entry_field_records->at_put(i, entry_fields->at(i)); |
| } |
| } |
| |
| // the Klasses of the objects in the sub-graphs |
| GrowableArray<Klass*>* subgraph_klasses = info->subgraph_object_klasses(); |
| if (subgraph_klasses != NULL) { |
| int num_subgraphs_klasses = subgraph_klasses->length(); |
| _subgraph_klasses = |
| MetaspaceShared::new_ro_array<Klass*>(num_subgraphs_klasses); |
| for (int i = 0; i < num_subgraphs_klasses; i++) { |
| Klass* subgraph_k = subgraph_klasses->at(i); |
| if (log_is_enabled(Info, cds, heap)) { |
| ResourceMark rm; |
| log_info(cds, heap)( |
| "Archived object klass (%d): %s in %s sub-graphs", |
| i, subgraph_k->external_name(), _k->external_name()); |
| } |
| _subgraph_klasses->at_put(i, subgraph_k); |
| } |
| } |
| } |
| |
| // Build the records of archived subgraph infos, which include: |
| // - Entry points to all subgraphs from the containing class mirror. The entry |
| // points are static fields in the mirror. For each entry point, the field |
| // offset and value are recorded in the sub-graph info. The value are stored |
| // back to the corresponding field at runtime. |
| // - A list of klasses that need to be loaded/initialized before archived |
| // java object sub-graph can be accessed at runtime. |
| // |
| // The records are saved in the archive file and reloaded at runtime. Currently |
| // there is only one class mirror (ArchivedModuleGraph) with archived sub-graphs. |
| // |
| // Layout of the archived subgraph info records: |
| // |
| // records_size | num_records | records* |
| // ArchivedKlassSubGraphInfoRecord | entry_fields | subgraph_object_klasses |
| size_t HeapShared::build_archived_subgraph_info_records(int num_records) { |
| // remember the start address |
| char* start_p = MetaspaceShared::read_only_space_top(); |
| |
| // now populate the archived subgraph infos, which will be saved in the |
| // archive file |
| _archived_subgraph_info_records = |
| MetaspaceShared::new_ro_array<ArchivedKlassSubGraphInfoRecord>(num_records); |
| KlassSubGraphInfo* info = _subgraph_info_list; |
| int i = 0; |
| while (info != NULL) { |
| assert(i < _archived_subgraph_info_records->length(), "sanity"); |
| ArchivedKlassSubGraphInfoRecord* record = |
| _archived_subgraph_info_records->adr_at(i); |
| record->init(info); |
| info = info->next(); |
| i ++; |
| } |
| |
| // _subgraph_info_list is no longer needed |
| delete _subgraph_info_list; |
| _subgraph_info_list = NULL; |
| |
| char* end_p = MetaspaceShared::read_only_space_top(); |
| size_t records_size = end_p - start_p; |
| return records_size; |
| } |
| |
| // Write the subgraph info records in the shared _ro region |
| void HeapShared::write_archived_subgraph_infos() { |
| assert(DumpSharedSpaces, "dump time only"); |
| |
| Array<intptr_t>* records_header = MetaspaceShared::new_ro_array<intptr_t>(3); |
| |
| _num_archived_subgraph_info_records = num_of_subgraph_infos(); |
| size_t records_size = build_archived_subgraph_info_records( |
| _num_archived_subgraph_info_records); |
| |
| // Now write the header information: |
| // records_size, num_records, _archived_subgraph_info_records |
| assert(records_header != NULL, "sanity"); |
| intptr_t* p = (intptr_t*)(records_header->data()); |
| *p = (intptr_t)records_size; |
| p ++; |
| *p = (intptr_t)_num_archived_subgraph_info_records; |
| p ++; |
| *p = (intptr_t)_archived_subgraph_info_records; |
| } |
| |
| char* HeapShared::read_archived_subgraph_infos(char* buffer) { |
| Array<intptr_t>* records_header = (Array<intptr_t>*)buffer; |
| intptr_t* p = (intptr_t*)(records_header->data()); |
| size_t records_size = (size_t)(*p); |
| p ++; |
| _num_archived_subgraph_info_records = *p; |
| p ++; |
| _archived_subgraph_info_records = |
| (Array<ArchivedKlassSubGraphInfoRecord>*)(*p); |
| |
| buffer = (char*)_archived_subgraph_info_records + records_size; |
| return buffer; |
| } |
| |
| void HeapShared::initialize_from_archived_subgraph(Klass* k) { |
| if (!MetaspaceShared::open_archive_heap_region_mapped()) { |
| return; // nothing to do |
| } |
| |
| if (_num_archived_subgraph_info_records == 0) { |
| return; // no subgraph info records |
| } |
| |
| // Initialize from archived data. Currently only ArchivedModuleGraph |
| // has archived object subgraphs, which is used during VM initialization |
| // time when bootstraping the system modules. No lock is needed. |
| Thread* THREAD = Thread::current(); |
| for (int i = 0; i < _archived_subgraph_info_records->length(); i++) { |
| ArchivedKlassSubGraphInfoRecord* record = _archived_subgraph_info_records->adr_at(i); |
| if (record->klass() == k) { |
| int i; |
| // Found the archived subgraph info record for the requesting klass. |
| // Load/link/initialize the klasses of the objects in the subgraph. |
| // NULL class loader is used. |
| Array<Klass*>* klasses = record->subgraph_klasses(); |
| if (klasses != NULL) { |
| for (i = 0; i < klasses->length(); i++) { |
| Klass* obj_k = klasses->at(i); |
| Klass* resolved_k = SystemDictionary::resolve_or_null( |
| (obj_k)->name(), THREAD); |
| if (resolved_k != obj_k) { |
| return; |
| } |
| if ((obj_k)->is_instance_klass()) { |
| InstanceKlass* ik = InstanceKlass::cast(obj_k); |
| ik->initialize(THREAD); |
| } else if ((obj_k)->is_objArray_klass()) { |
| ObjArrayKlass* oak = ObjArrayKlass::cast(obj_k); |
| oak->initialize(THREAD); |
| } |
| } |
| } |
| |
| if (HAS_PENDING_EXCEPTION) { |
| CLEAR_PENDING_EXCEPTION; |
| // None of the field value will be set if there was an exception. |
| // The java code will not see any of the archived objects in the |
| // subgraphs referenced from k in this case. |
| return; |
| } |
| |
| // Load the subgraph entry fields from the record and store them back to |
| // the corresponding fields within the mirror. |
| oop m = k->java_mirror(); |
| Array<juint>* entry_field_records = record->entry_field_records(); |
| if (entry_field_records != NULL) { |
| int efr_len = entry_field_records->length(); |
| assert(efr_len % 2 == 0, "sanity"); |
| for (i = 0; i < efr_len;) { |
| int field_offset = entry_field_records->at(i); |
| // The object refereced by the field becomes 'known' by GC from this |
| // point. All objects in the subgraph reachable from the object are |
| // also 'known' by GC. |
| oop v = MetaspaceShared::materialize_archived_object( |
| CompressedOops::decode(entry_field_records->at(i+1))); |
| m->obj_field_put(field_offset, v); |
| i += 2; |
| } |
| } |
| |
| // Done. Java code can see the archived sub-graphs referenced from k's |
| // mirror after this point. |
| return; |
| } |
| } |
| } |
| |
| class WalkOopAndArchiveClosure: public BasicOopIterateClosure { |
| int _level; |
| KlassSubGraphInfo* _subgraph_info; |
| oop _orig_referencing_obj; |
| oop _archived_referencing_obj; |
| public: |
| WalkOopAndArchiveClosure(int level, KlassSubGraphInfo* subgraph_info, |
| oop orig, oop archived) : _level(level), |
| _subgraph_info(subgraph_info), |
| _orig_referencing_obj(orig), |
| _archived_referencing_obj(archived) {} |
| void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); } |
| void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); } |
| |
| protected: |
| template <class T> void do_oop_work(T *p) { |
| oop obj = RawAccess<>::oop_load(p); |
| if (!CompressedOops::is_null(obj)) { |
| // A java.lang.Class instance can not be included in an archived |
| // object sub-graph. |
| if (java_lang_Class::is_instance(obj)) { |
| log_error(cds, heap)("Unknown java.lang.Class object is in the archived sub-graph\n"); |
| vm_exit(1); |
| } |
| |
| LogTarget(Debug, cds, heap) log; |
| LogStream ls(log); |
| outputStream* out = &ls; |
| { |
| ResourceMark rm; |
| log.print("(%d) %s <--- referenced from: %s", |
| _level, obj->klass()->external_name(), |
| CompressedOops::is_null(_orig_referencing_obj) ? |
| "" : _orig_referencing_obj->klass()->external_name()); |
| obj->print_on(out); |
| } |
| |
| if (MetaspaceShared::is_archive_object(obj)) { |
| // The current oop is an archived oop, nothing needs to be done |
| log.print("--- object is already archived ---"); |
| return; |
| } |
| |
| size_t field_delta = pointer_delta( |
| p, _orig_referencing_obj, sizeof(char)); |
| T* new_p = (T*)(address(_archived_referencing_obj) + field_delta); |
| oop archived = MetaspaceShared::find_archived_heap_object(obj); |
| if (archived != NULL) { |
| // There is an archived copy existing, update reference to point |
| // to the archived copy |
| RawAccess<IS_NOT_NULL>::oop_store(new_p, archived); |
| log.print( |
| "--- found existing archived copy, store archived " PTR_FORMAT " in " PTR_FORMAT, |
| p2i(archived), p2i(new_p)); |
| return; |
| } |
| |
| int l = _level + 1; |
| Thread* THREAD = Thread::current(); |
| // Archive the current oop before iterating through its references |
| archived = MetaspaceShared::archive_heap_object(obj, THREAD); |
| if (archived == NULL) { |
| ResourceMark rm; |
| LogTarget(Error, cds, heap) log_err; |
| LogStream ls_err(log_err); |
| outputStream* out_err = &ls_err; |
| log_err.print("Failed to archive %s object (" |
| PTR_FORMAT "), size[" SIZE_FORMAT "] in sub-graph", |
| obj->klass()->external_name(), p2i(obj), (size_t)obj->size()); |
| obj->print_on(out_err); |
| vm_exit(1); |
| } |
| assert(MetaspaceShared::is_archive_object(archived), "must be archived"); |
| log.print("=== archiving oop " PTR_FORMAT " ==> " PTR_FORMAT, |
| p2i(obj), p2i(archived)); |
| |
| // Following the references in the current oop and archive any |
| // encountered objects during the process |
| WalkOopAndArchiveClosure walker(l, _subgraph_info, obj, archived); |
| obj->oop_iterate(&walker); |
| |
| // Update the reference in the archived copy of the referencing object |
| RawAccess<IS_NOT_NULL>::oop_store(new_p, archived); |
| log.print("=== store archived " PTR_FORMAT " in " PTR_FORMAT, |
| p2i(archived), p2i(new_p)); |
| |
| // Add the klass to the list of classes that need to be loaded before |
| // module system initialization |
| Klass *orig_k = obj->klass(); |
| Klass *relocated_k = archived->klass(); |
| _subgraph_info->add_subgraph_object_klass(orig_k, relocated_k); |
| } |
| } |
| }; |
| |
| // |
| // Start from the given static field in a java mirror and archive the |
| // complete sub-graph of java heap objects that are reached directly |
| // or indirectly from the starting object by following references. |
| // Currently, only ArchivedModuleGraph class instance (mirror) has archived |
| // object subgraphs. Sub-graph archiving restrictions (current): |
| // |
| // - All classes of objects in the archived sub-graph (including the |
| // entry class) must be boot class only. |
| // - No java.lang.Class instance (java mirror) can be included inside |
| // an archived sub-graph. Mirror can only be the sub-graph entry object. |
| // |
| // The Java heap object sub-graph archiving process (see |
| // WalkOopAndArchiveClosure): |
| // |
| // 1) Java object sub-graph archiving starts from a given static field |
| // within a Class instance (java mirror). If the static field is a |
| // refererence field and points to a non-null java object, proceed to |
| // the next step. |
| // |
| // 2) Archives the referenced java object. If an archived copy of the |
| // current object already exists, updates the pointer in the archived |
| // copy of the referencing object to point to the current archived object. |
| // Otherwise, proceed to the next step. |
| // |
| // 3) Follows all references within the current java object and recursively |
| // archive the sub-graph of objects starting from each reference. |
| // |
| // 4) Updates the pointer in the archived copy of referencing object to |
| // point to the current archived object. |
| // |
| // 5) The Klass of the current java object is added to the list of Klasses |
| // for loading and initialzing before any object in the archived graph can |
| // be accessed at runtime. |
| // |
| void HeapShared::archive_reachable_objects_from_static_field(Klass *k, |
| int field_offset, |
| BasicType field_type, |
| TRAPS) { |
| assert(DumpSharedSpaces, "dump time only"); |
| assert(k->is_instance_klass(), "sanity"); |
| assert(InstanceKlass::cast(k)->is_shared_boot_class(), |
| "must be boot class"); |
| |
| oop m = k->java_mirror(); |
| oop archived_m = MetaspaceShared::find_archived_heap_object(m); |
| if (CompressedOops::is_null(archived_m)) { |
| return; |
| } |
| |
| if (field_type == T_OBJECT) { |
| // obtain k's subGraph Info |
| KlassSubGraphInfo* subgraph_info = get_subgraph_info(k); |
| |
| // get the object referenced by the field |
| oop f = m->obj_field(field_offset); |
| if (!CompressedOops::is_null(f)) { |
| LogTarget(Debug, cds, heap) log; |
| LogStream ls(log); |
| outputStream* out = &ls; |
| log.print("Start from: "); |
| f->print_on(out); |
| |
| // get the archived copy of the field referenced object |
| oop af = MetaspaceShared::archive_heap_object(f, THREAD); |
| if (af == NULL) { |
| // Skip archiving the sub-graph referenced from the current entry field. |
| ResourceMark rm; |
| log_info(cds, heap)( |
| "Cannot archive the sub-graph referenced from %s object (" |
| PTR_FORMAT ") size[" SIZE_FORMAT "], skipped.", |
| f->klass()->external_name(), p2i(f), (size_t)f->size()); |
| return; |
| } |
| if (!MetaspaceShared::is_archive_object(f)) { |
| WalkOopAndArchiveClosure walker(1, subgraph_info, f, af); |
| f->oop_iterate(&walker); |
| } |
| |
| // The field value is not preserved in the archived mirror. |
| // Record the field as a new subGraph entry point. The recorded |
| // information is restored from the archive at runtime. |
| subgraph_info->add_subgraph_entry_field(field_offset, af); |
| Klass *relocated_k = af->klass(); |
| Klass *orig_k = f->klass(); |
| subgraph_info->add_subgraph_object_klass(orig_k, relocated_k); |
| ResourceMark rm; |
| log_info(cds, heap)( |
| "Archived the sub-graph referenced from %s object " PTR_FORMAT, |
| f->klass()->external_name(), p2i(f)); |
| } else { |
| // The field contains null, we still need to record the entry point, |
| // so it can be restored at runtime. |
| subgraph_info->add_subgraph_entry_field(field_offset, NULL); |
| } |
| } else { |
| ShouldNotReachHere(); |
| } |
| } |
| |
| #define do_module_object_graph(archive_object_graph_do) \ |
| archive_object_graph_do(SystemDictionary::ArchivedModuleGraph_klass(), jdk_internal_module_ArchivedModuleGraph::archivedSystemModules_offset(), T_OBJECT, CHECK); \ |
| archive_object_graph_do(SystemDictionary::ArchivedModuleGraph_klass(), jdk_internal_module_ArchivedModuleGraph::archivedModuleFinder_offset(), T_OBJECT, CHECK); \ |
| archive_object_graph_do(SystemDictionary::ArchivedModuleGraph_klass(), jdk_internal_module_ArchivedModuleGraph::archivedMainModule_offset(), T_OBJECT, CHECK); \ |
| archive_object_graph_do(SystemDictionary::ArchivedModuleGraph_klass(), jdk_internal_module_ArchivedModuleGraph::archivedConfiguration_offset(), T_OBJECT, CHECK); \ |
| archive_object_graph_do(SystemDictionary::ImmutableCollections_ListN_klass(), java_util_ImmutableCollections_ListN::EMPTY_LIST_offset(), T_OBJECT, CHECK); \ |
| archive_object_graph_do(SystemDictionary::ImmutableCollections_MapN_klass(), java_util_ImmutableCollections_MapN::EMPTY_MAP_offset(), T_OBJECT, CHECK); \ |
| archive_object_graph_do(SystemDictionary::ImmutableCollections_SetN_klass(), java_util_ImmutableCollections_SetN::EMPTY_SET_offset(), T_OBJECT, CHECK); \ |
| archive_object_graph_do(SystemDictionary::Integer_IntegerCache_klass(), java_lang_Integer_IntegerCache::archivedCache_offset(), T_OBJECT, CHECK); \ |
| archive_object_graph_do(SystemDictionary::Configuration_klass(), java_lang_module_Configuration::EMPTY_CONFIGURATION_offset(), T_OBJECT, CHECK) |
| |
| void HeapShared::archive_module_graph_objects(Thread* THREAD) { |
| do_module_object_graph(archive_reachable_objects_from_static_field); |
| } |
| #endif // INCLUDE_CDS_JAVA_HEAP |
