/* * Copyright (c) 2012, 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 "jvm.h" #include "classfile/classLoaderDataGraph.hpp" #include "classfile/classListParser.hpp" #include "classfile/classLoaderExt.hpp" #include "classfile/dictionary.hpp" #include "classfile/loaderConstraints.hpp" #include "classfile/placeholders.hpp" #include "classfile/symbolTable.hpp" #include "classfile/stringTable.hpp" #include "classfile/systemDictionary.hpp" #include "classfile/systemDictionaryShared.hpp" #include "code/codeCache.hpp" #include "interpreter/bytecodeStream.hpp" #include "interpreter/bytecodes.hpp" #include "logging/log.hpp" #include "logging/logMessage.hpp" #include "memory/filemap.hpp" #include "memory/heapShared.inline.hpp" #include "memory/metaspace.hpp" #include "memory/metaspaceClosure.hpp" #include "memory/metaspaceShared.hpp" #include "memory/resourceArea.hpp" #include "oops/compressedOops.inline.hpp" #include "oops/instanceClassLoaderKlass.hpp" #include "oops/instanceMirrorKlass.hpp" #include "oops/instanceRefKlass.hpp" #include "oops/objArrayKlass.hpp" #include "oops/objArrayOop.hpp" #include "oops/oop.inline.hpp" #include "oops/typeArrayKlass.hpp" #include "prims/jvmtiRedefineClasses.hpp" #include "runtime/handles.inline.hpp" #include "runtime/os.hpp" #include "runtime/safepointVerifiers.hpp" #include "runtime/signature.hpp" #include "runtime/timerTrace.hpp" #include "runtime/vmThread.hpp" #include "runtime/vm_operations.hpp" #include "utilities/align.hpp" #include "utilities/bitMap.hpp" #include "utilities/defaultStream.hpp" #include "utilities/hashtable.inline.hpp" #if INCLUDE_G1GC #include "gc/g1/g1CollectedHeap.hpp" #endif ReservedSpace MetaspaceShared::_shared_rs; VirtualSpace MetaspaceShared::_shared_vs; MetaspaceSharedStats MetaspaceShared::_stats; bool MetaspaceShared::_has_error_classes; bool MetaspaceShared::_archive_loading_failed = false; bool MetaspaceShared::_remapped_readwrite = false; address MetaspaceShared::_cds_i2i_entry_code_buffers = NULL; size_t MetaspaceShared::_cds_i2i_entry_code_buffers_size = 0; size_t MetaspaceShared::_core_spaces_size = 0; // The CDS archive is divided into the following regions: // mc - misc code (the method entry trampolines) // rw - read-write metadata // ro - read-only metadata and read-only tables // md - misc data (the c++ vtables) // od - optional data (original class files) // // ca0 - closed archive heap space #0 // ca1 - closed archive heap space #1 (may be empty) // oa0 - open archive heap space #0 // oa1 - open archive heap space #1 (may be empty) // // The mc, rw, ro, md and od regions are linearly allocated, starting from // SharedBaseAddress, in the order of mc->rw->ro->md->od. The size of these 5 regions // are page-aligned, and there's no gap between any consecutive regions. // // These 5 regions are populated in the following steps: // [1] All classes are loaded in MetaspaceShared::preload_classes(). All metadata are // temporarily allocated outside of the shared regions. Only the method entry // trampolines are written into the mc region. // [2] ArchiveCompactor copies RW metadata into the rw region. // [3] ArchiveCompactor copies RO metadata into the ro region. // [4] SymbolTable, StringTable, SystemDictionary, and a few other read-only data // are copied into the ro region as read-only tables. // [5] C++ vtables are copied into the md region. // [6] Original class files are copied into the od region. // // The s0/s1 and oa0/oa1 regions are populated inside HeapShared::archive_java_heap_objects. // Their layout is independent of the other 5 regions. class DumpRegion { private: const char* _name; char* _base; char* _top; char* _end; bool _is_packed; char* expand_top_to(char* newtop) { assert(is_allocatable(), "must be initialized and not packed"); assert(newtop >= _top, "must not grow backwards"); if (newtop > _end) { MetaspaceShared::report_out_of_space(_name, newtop - _top); ShouldNotReachHere(); } uintx delta = MetaspaceShared::object_delta_uintx(newtop); if (delta > MAX_SHARED_DELTA) { // This is just a sanity check and should not appear in any real world usage. This // happens only if you allocate more than 2GB of shared objects and would require // millions of shared classes. vm_exit_during_initialization("Out of memory in the CDS archive", "Please reduce the number of shared classes."); } MetaspaceShared::commit_shared_space_to(newtop); _top = newtop; return _top; } public: DumpRegion(const char* name) : _name(name), _base(NULL), _top(NULL), _end(NULL), _is_packed(false) {} char* allocate(size_t num_bytes, size_t alignment=BytesPerWord) { char* p = (char*)align_up(_top, alignment); char* newtop = p + align_up(num_bytes, alignment); expand_top_to(newtop); memset(p, 0, newtop - p); return p; } void append_intptr_t(intptr_t n) { assert(is_aligned(_top, sizeof(intptr_t)), "bad alignment"); intptr_t *p = (intptr_t*)_top; char* newtop = _top + sizeof(intptr_t); expand_top_to(newtop); *p = n; } char* base() const { return _base; } char* top() const { return _top; } char* end() const { return _end; } size_t reserved() const { return _end - _base; } size_t used() const { return _top - _base; } bool is_packed() const { return _is_packed; } bool is_allocatable() const { return !is_packed() && _base != NULL; } void print(size_t total_bytes) const { tty->print_cr("%-3s space: " SIZE_FORMAT_W(9) " [ %4.1f%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used] at " INTPTR_FORMAT, _name, used(), percent_of(used(), total_bytes), reserved(), percent_of(used(), reserved()), p2i(_base)); } void print_out_of_space_msg(const char* failing_region, size_t needed_bytes) { tty->print("[%-8s] " PTR_FORMAT " - " PTR_FORMAT " capacity =%9d, allocated =%9d", _name, p2i(_base), p2i(_top), int(_end - _base), int(_top - _base)); if (strcmp(_name, failing_region) == 0) { tty->print_cr(" required = %d", int(needed_bytes)); } else { tty->cr(); } } void init(const ReservedSpace* rs) { _base = _top = rs->base(); _end = rs->end(); } void init(char* b, char* t, char* e) { _base = b; _top = t; _end = e; } void pack(DumpRegion* next = NULL) { assert(!is_packed(), "sanity"); _end = (char*)align_up(_top, Metaspace::reserve_alignment()); _is_packed = true; if (next != NULL) { next->_base = next->_top = this->_end; next->_end = MetaspaceShared::shared_rs()->end(); } } bool contains(char* p) { return base() <= p && p < top(); } }; DumpRegion _mc_region("mc"), _ro_region("ro"), _rw_region("rw"), _md_region("md"), _od_region("od"); size_t _total_closed_archive_region_size = 0, _total_open_archive_region_size = 0; char* MetaspaceShared::misc_code_space_alloc(size_t num_bytes) { return _mc_region.allocate(num_bytes); } char* MetaspaceShared::read_only_space_alloc(size_t num_bytes) { return _ro_region.allocate(num_bytes); } char* MetaspaceShared::read_only_space_top() { return _ro_region.top(); } void MetaspaceShared::initialize_runtime_shared_and_meta_spaces() { assert(UseSharedSpaces, "Must be called when UseSharedSpaces is enabled"); // If using shared space, open the file that contains the shared space // and map in the memory before initializing the rest of metaspace (so // the addresses don't conflict) address cds_address = NULL; FileMapInfo* mapinfo = new FileMapInfo(); // Open the shared archive file, read and validate the header. If // initialization fails, shared spaces [UseSharedSpaces] are // disabled and the file is closed. // Map in spaces now also if (mapinfo->initialize() && map_shared_spaces(mapinfo)) { size_t cds_total = core_spaces_size(); cds_address = (address)mapinfo->region_addr(0); #ifdef _LP64 if (Metaspace::using_class_space()) { char* cds_end = (char*)(cds_address + cds_total); cds_end = (char *)align_up(cds_end, Metaspace::reserve_alignment()); // If UseCompressedClassPointers is set then allocate the metaspace area // above the heap and above the CDS area (if it exists). Metaspace::allocate_metaspace_compressed_klass_ptrs(cds_end, cds_address); // map_heap_regions() compares the current narrow oop and klass encodings // with the archived ones, so it must be done after all encodings are determined. mapinfo->map_heap_regions(); } Universe::set_narrow_klass_range(CompressedClassSpaceSize); #endif // _LP64 } else { assert(!mapinfo->is_open() && !UseSharedSpaces, "archive file not closed or shared spaces not disabled."); } } void MetaspaceShared::initialize_dumptime_shared_and_meta_spaces() { assert(DumpSharedSpaces, "should be called for dump time only"); const size_t reserve_alignment = Metaspace::reserve_alignment(); bool large_pages = false; // No large pages when dumping the CDS archive. char* shared_base = (char*)align_up((char*)SharedBaseAddress, reserve_alignment); #ifdef _LP64 // On 64-bit VM, the heap and class space layout will be the same as if // you're running in -Xshare:on mode: // // +-- SharedBaseAddress (default = 0x800000000) // v // +-..---------+---------+ ... +----+----+----+----+----+---------------+ // | Heap | Archive | | MC | RW | RO | MD | OD | class space | // +-..---------+---------+ ... +----+----+----+----+----+---------------+ // |<-- MaxHeapSize -->| |<-- UnscaledClassSpaceMax = 4GB ------->| // const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1); const size_t cds_total = align_down(UnscaledClassSpaceMax, reserve_alignment); #else // We don't support archives larger than 256MB on 32-bit due to limited virtual address space. size_t cds_total = align_down(256*M, reserve_alignment); #endif // First try to reserve the space at the specified SharedBaseAddress. _shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages, shared_base); if (_shared_rs.is_reserved()) { assert(shared_base == 0 || _shared_rs.base() == shared_base, "should match"); } else { // Get a mmap region anywhere if the SharedBaseAddress fails. _shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages); } if (!_shared_rs.is_reserved()) { vm_exit_during_initialization("Unable to reserve memory for shared space", err_msg(SIZE_FORMAT " bytes.", cds_total)); } #ifdef _LP64 // During dump time, we allocate 4GB (UnscaledClassSpaceMax) of space and split it up: // + The upper 1 GB is used as the "temporary compressed class space" -- preload_classes() // will store Klasses into this space. // + The lower 3 GB is used for the archive -- when preload_classes() is done, // ArchiveCompactor will copy the class metadata into this space, first the RW parts, // then the RO parts. assert(UseCompressedOops && UseCompressedClassPointers, "UseCompressedOops and UseCompressedClassPointers must be set"); size_t max_archive_size = align_down(cds_total * 3 / 4, reserve_alignment); ReservedSpace tmp_class_space = _shared_rs.last_part(max_archive_size); CompressedClassSpaceSize = align_down(tmp_class_space.size(), reserve_alignment); _shared_rs = _shared_rs.first_part(max_archive_size); // Set up compress class pointers. Universe::set_narrow_klass_base((address)_shared_rs.base()); // Set narrow_klass_shift to be LogKlassAlignmentInBytes. This is consistent // with AOT. Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes); // Set the range of klass addresses to 4GB. Universe::set_narrow_klass_range(cds_total); Metaspace::initialize_class_space(tmp_class_space); log_info(cds)("narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d", p2i(Universe::narrow_klass_base()), Universe::narrow_klass_shift()); log_info(cds)("Allocated temporary class space: " SIZE_FORMAT " bytes at " PTR_FORMAT, CompressedClassSpaceSize, p2i(tmp_class_space.base())); #endif // Start with 0 committed bytes. The memory will be committed as needed by // MetaspaceShared::commit_shared_space_to(). if (!_shared_vs.initialize(_shared_rs, 0)) { vm_exit_during_initialization("Unable to allocate memory for shared space"); } _mc_region.init(&_shared_rs); SharedBaseAddress = (size_t)_shared_rs.base(); tty->print_cr("Allocated shared space: " SIZE_FORMAT " bytes at " PTR_FORMAT, _shared_rs.size(), p2i(_shared_rs.base())); } // Called by universe_post_init() void MetaspaceShared::post_initialize(TRAPS) { if (UseSharedSpaces) { int size = FileMapInfo::get_number_of_shared_paths(); if (size > 0) { SystemDictionaryShared::allocate_shared_data_arrays(size, THREAD); FileMapHeader* header = FileMapInfo::current_info()->header(); ClassLoaderExt::init_paths_start_index(header->_app_class_paths_start_index); ClassLoaderExt::init_app_module_paths_start_index(header->_app_module_paths_start_index); } } } void MetaspaceShared::read_extra_data(const char* filename, TRAPS) { HashtableTextDump reader(filename); reader.check_version("VERSION: 1.0"); while (reader.remain() > 0) { int utf8_length; int prefix_type = reader.scan_prefix(&utf8_length); ResourceMark rm(THREAD); char* utf8_buffer = NEW_RESOURCE_ARRAY(char, utf8_length); reader.get_utf8(utf8_buffer, utf8_length); if (prefix_type == HashtableTextDump::SymbolPrefix) { SymbolTable::new_symbol(utf8_buffer, utf8_length, THREAD); } else{ assert(prefix_type == HashtableTextDump::StringPrefix, "Sanity"); utf8_buffer[utf8_length] = '\0'; oop s = StringTable::intern(utf8_buffer, THREAD); } } } void MetaspaceShared::commit_shared_space_to(char* newtop) { assert(DumpSharedSpaces, "dump-time only"); char* base = _shared_rs.base(); size_t need_committed_size = newtop - base; size_t has_committed_size = _shared_vs.committed_size(); if (need_committed_size < has_committed_size) { return; } size_t min_bytes = need_committed_size - has_committed_size; size_t preferred_bytes = 1 * M; size_t uncommitted = _shared_vs.reserved_size() - has_committed_size; size_t commit = MAX2(min_bytes, preferred_bytes); assert(commit <= uncommitted, "sanity"); bool result = _shared_vs.expand_by(commit, false); if (!result) { vm_exit_during_initialization(err_msg("Failed to expand shared space to " SIZE_FORMAT " bytes", need_committed_size)); } log_info(cds)("Expanding shared spaces by " SIZE_FORMAT_W(7) " bytes [total " SIZE_FORMAT_W(9) " bytes ending at %p]", commit, _shared_vs.actual_committed_size(), _shared_vs.high()); } // Read/write a data stream for restoring/preserving metadata pointers and // miscellaneous data from/to the shared archive file. void MetaspaceShared::serialize(SerializeClosure* soc) { int tag = 0; soc->do_tag(--tag); // Verify the sizes of various metadata in the system. soc->do_tag(sizeof(Method)); soc->do_tag(sizeof(ConstMethod)); soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE)); soc->do_tag(sizeof(ConstantPool)); soc->do_tag(sizeof(ConstantPoolCache)); soc->do_tag(objArrayOopDesc::base_offset_in_bytes()); soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE)); soc->do_tag(sizeof(Symbol)); // Dump/restore miscellaneous metadata. Universe::serialize(soc); soc->do_tag(--tag); // Dump/restore references to commonly used names and signatures. vmSymbols::serialize(soc); soc->do_tag(--tag); // Dump/restore the symbol/string/subgraph_info tables SymbolTable::serialize_shared_table_header(soc); StringTable::serialize_shared_table_header(soc); HeapShared::serialize_subgraph_info_table_header(soc); SystemDictionaryShared::serialize_dictionary_headers(soc); JavaClasses::serialize_offsets(soc); InstanceMirrorKlass::serialize_offsets(soc); soc->do_tag(--tag); soc->do_tag(666); } address MetaspaceShared::cds_i2i_entry_code_buffers(size_t total_size) { if (DumpSharedSpaces) { if (_cds_i2i_entry_code_buffers == NULL) { _cds_i2i_entry_code_buffers = (address)misc_code_space_alloc(total_size); _cds_i2i_entry_code_buffers_size = total_size; } } else if (UseSharedSpaces) { assert(_cds_i2i_entry_code_buffers != NULL, "must already been initialized"); } else { return NULL; } assert(_cds_i2i_entry_code_buffers_size == total_size, "must not change"); return _cds_i2i_entry_code_buffers; } // CDS code for dumping shared archive. // Global object for holding classes that have been loaded. Since this // is run at a safepoint just before exit, this is the entire set of classes. static GrowableArray* _global_klass_objects; GrowableArray* MetaspaceShared::collected_klasses() { return _global_klass_objects; } static void collect_array_classes(Klass* k) { _global_klass_objects->append_if_missing(k); if (k->is_array_klass()) { // Add in the array classes too ArrayKlass* ak = ArrayKlass::cast(k); Klass* h = ak->higher_dimension(); if (h != NULL) { h->array_klasses_do(collect_array_classes); } } } class CollectClassesClosure : public KlassClosure { void do_klass(Klass* k) { if (k->is_instance_klass() && SystemDictionaryShared::is_excluded_class(InstanceKlass::cast(k))) { // Don't add to the _global_klass_objects } else { _global_klass_objects->append_if_missing(k); } if (k->is_array_klass()) { // Add in the array classes too ArrayKlass* ak = ArrayKlass::cast(k); Klass* h = ak->higher_dimension(); if (h != NULL) { h->array_klasses_do(collect_array_classes); } } } }; static void remove_unshareable_in_classes() { for (int i = 0; i < _global_klass_objects->length(); i++) { Klass* k = _global_klass_objects->at(i); if (!k->is_objArray_klass()) { // InstanceKlass and TypeArrayKlass will in turn call remove_unshareable_info // on their array classes. assert(k->is_instance_klass() || k->is_typeArray_klass(), "must be"); k->remove_unshareable_info(); } } } static void remove_java_mirror_in_classes() { for (int i = 0; i < _global_klass_objects->length(); i++) { Klass* k = _global_klass_objects->at(i); if (!k->is_objArray_klass()) { // InstanceKlass and TypeArrayKlass will in turn call remove_unshareable_info // on their array classes. assert(k->is_instance_klass() || k->is_typeArray_klass(), "must be"); k->remove_java_mirror(); } } } static void clear_basic_type_mirrors() { assert(!HeapShared::is_heap_object_archiving_allowed(), "Sanity"); Universe::set_int_mirror(NULL); Universe::set_float_mirror(NULL); Universe::set_double_mirror(NULL); Universe::set_byte_mirror(NULL); Universe::set_bool_mirror(NULL); Universe::set_char_mirror(NULL); Universe::set_long_mirror(NULL); Universe::set_short_mirror(NULL); Universe::set_void_mirror(NULL); } static void rewrite_nofast_bytecode(Method* method) { BytecodeStream bcs(method); while (!bcs.is_last_bytecode()) { Bytecodes::Code opcode = bcs.next(); switch (opcode) { case Bytecodes::_getfield: *bcs.bcp() = Bytecodes::_nofast_getfield; break; case Bytecodes::_putfield: *bcs.bcp() = Bytecodes::_nofast_putfield; break; case Bytecodes::_aload_0: *bcs.bcp() = Bytecodes::_nofast_aload_0; break; case Bytecodes::_iload: { if (!bcs.is_wide()) { *bcs.bcp() = Bytecodes::_nofast_iload; } break; } default: break; } } } // Walk all methods in the class list to ensure that they won't be modified at // run time. This includes: // [1] Rewrite all bytecodes as needed, so that the ConstMethod* will not be modified // at run time by RewriteBytecodes/RewriteFrequentPairs // [2] Assign a fingerprint, so one doesn't need to be assigned at run-time. static void rewrite_nofast_bytecodes_and_calculate_fingerprints() { for (int i = 0; i < _global_klass_objects->length(); i++) { Klass* k = _global_klass_objects->at(i); if (k->is_instance_klass()) { InstanceKlass* ik = InstanceKlass::cast(k); for (int i = 0; i < ik->methods()->length(); i++) { Method* m = ik->methods()->at(i); rewrite_nofast_bytecode(m); Fingerprinter fp(m); // The side effect of this call sets method's fingerprint field. fp.fingerprint(); } } } } static void relocate_cached_class_file() { for (int i = 0; i < _global_klass_objects->length(); i++) { Klass* k = _global_klass_objects->at(i); if (k->is_instance_klass()) { InstanceKlass* ik = InstanceKlass::cast(k); JvmtiCachedClassFileData* p = ik->get_archived_class_data(); if (p != NULL) { int size = offset_of(JvmtiCachedClassFileData, data) + p->length; JvmtiCachedClassFileData* q = (JvmtiCachedClassFileData*)_od_region.allocate(size); q->length = p->length; memcpy(q->data, p->data, p->length); ik->set_archived_class_data(q); } } } } // Objects of the Metadata types (such as Klass and ConstantPool) have C++ vtables. // (In GCC this is the field ::_vptr, i.e., first word in the object.) // // Addresses of the vtables and the methods may be different across JVM runs, // if libjvm.so is dynamically loaded at a different base address. // // To ensure that the Metadata objects in the CDS archive always have the correct vtable: // // + at dump time: we redirect the _vptr to point to our own vtables inside // the CDS image // + at run time: we clone the actual contents of the vtables from libjvm.so // into our own tables. // Currently, the archive contain ONLY the following types of objects that have C++ vtables. #define CPP_VTABLE_PATCH_TYPES_DO(f) \ f(ConstantPool) \ f(InstanceKlass) \ f(InstanceClassLoaderKlass) \ f(InstanceMirrorKlass) \ f(InstanceRefKlass) \ f(Method) \ f(ObjArrayKlass) \ f(TypeArrayKlass) class CppVtableInfo { intptr_t _vtable_size; intptr_t _cloned_vtable[1]; public: static int num_slots(int vtable_size) { return 1 + vtable_size; // Need to add the space occupied by _vtable_size; } int vtable_size() { return int(uintx(_vtable_size)); } void set_vtable_size(int n) { _vtable_size = intptr_t(n); } intptr_t* cloned_vtable() { return &_cloned_vtable[0]; } void zero() { memset(_cloned_vtable, 0, sizeof(intptr_t) * vtable_size()); } // Returns the address of the next CppVtableInfo that can be placed immediately after this CppVtableInfo static size_t byte_size(int vtable_size) { CppVtableInfo i; return pointer_delta(&i._cloned_vtable[vtable_size], &i, sizeof(u1)); } }; template class CppVtableCloner : public T { static intptr_t* vtable_of(Metadata& m) { return *((intptr_t**)&m); } static CppVtableInfo* _info; static int get_vtable_length(const char* name); public: // Allocate and initialize the C++ vtable, starting from top, but do not go past end. static intptr_t* allocate(const char* name); // Clone the vtable to ... static intptr_t* clone_vtable(const char* name, CppVtableInfo* info); static void zero_vtable_clone() { assert(DumpSharedSpaces, "dump-time only"); _info->zero(); } // Switch the vtable pointer to point to the cloned vtable. static void patch(Metadata* obj) { assert(DumpSharedSpaces, "dump-time only"); *(void**)obj = (void*)(_info->cloned_vtable()); } static bool is_valid_shared_object(const T* obj) { intptr_t* vptr = *(intptr_t**)obj; return vptr == _info->cloned_vtable(); } }; template CppVtableInfo* CppVtableCloner::_info = NULL; template intptr_t* CppVtableCloner::allocate(const char* name) { assert(is_aligned(_md_region.top(), sizeof(intptr_t)), "bad alignment"); int n = get_vtable_length(name); _info = (CppVtableInfo*)_md_region.allocate(CppVtableInfo::byte_size(n), sizeof(intptr_t)); _info->set_vtable_size(n); intptr_t* p = clone_vtable(name, _info); assert((char*)p == _md_region.top(), "must be"); return p; } template intptr_t* CppVtableCloner::clone_vtable(const char* name, CppVtableInfo* info) { if (!DumpSharedSpaces) { assert(_info == 0, "_info is initialized only at dump time"); _info = info; // Remember it -- it will be used by MetaspaceShared::is_valid_shared_method() } T tmp; // Allocate temporary dummy metadata object to get to the original vtable. int n = info->vtable_size(); intptr_t* srcvtable = vtable_of(tmp); intptr_t* dstvtable = info->cloned_vtable(); // We already checked (and, if necessary, adjusted n) when the vtables were allocated, so we are // safe to do memcpy. log_debug(cds, vtables)("Copying %3d vtable entries for %s", n, name); memcpy(dstvtable, srcvtable, sizeof(intptr_t) * n); return dstvtable + n; } // To determine the size of the vtable for each type, we use the following // trick by declaring 2 subclasses: // // class CppVtableTesterA: public InstanceKlass {virtual int last_virtual_method() {return 1;} }; // class CppVtableTesterB: public InstanceKlass {virtual void* last_virtual_method() {return NULL}; }; // // CppVtableTesterA and CppVtableTesterB's vtables have the following properties: // - Their size (N+1) is exactly one more than the size of InstanceKlass's vtable (N) // - The first N entries have are exactly the same as in InstanceKlass's vtable. // - Their last entry is different. // // So to determine the value of N, we just walk CppVtableTesterA and CppVtableTesterB's tables // and find the first entry that's different. // // This works on all C++ compilers supported by Oracle, but you may need to tweak it for more // esoteric compilers. template class CppVtableTesterB: public T { public: virtual int last_virtual_method() {return 1;} }; template class CppVtableTesterA : public T { public: virtual void* last_virtual_method() { // Make this different than CppVtableTesterB::last_virtual_method so the C++ // compiler/linker won't alias the two functions. return NULL; } }; template int CppVtableCloner::get_vtable_length(const char* name) { CppVtableTesterA a; CppVtableTesterB b; intptr_t* avtable = vtable_of(a); intptr_t* bvtable = vtable_of(b); // Start at slot 1, because slot 0 may be RTTI (on Solaris/Sparc) int vtable_len = 1; for (; ; vtable_len++) { if (avtable[vtable_len] != bvtable[vtable_len]) { break; } } log_debug(cds, vtables)("Found %3d vtable entries for %s", vtable_len, name); return vtable_len; } #define ALLOC_CPP_VTABLE_CLONE(c) \ CppVtableCloner::allocate(#c); #define CLONE_CPP_VTABLE(c) \ p = CppVtableCloner::clone_vtable(#c, (CppVtableInfo*)p); #define ZERO_CPP_VTABLE(c) \ CppVtableCloner::zero_vtable_clone(); // This can be called at both dump time and run time. intptr_t* MetaspaceShared::clone_cpp_vtables(intptr_t* p) { assert(DumpSharedSpaces || UseSharedSpaces, "sanity"); CPP_VTABLE_PATCH_TYPES_DO(CLONE_CPP_VTABLE); return p; } void MetaspaceShared::zero_cpp_vtable_clones_for_writing() { assert(DumpSharedSpaces, "dump-time only"); CPP_VTABLE_PATCH_TYPES_DO(ZERO_CPP_VTABLE); } // Allocate and initialize the C++ vtables, starting from top, but do not go past end. void MetaspaceShared::allocate_cpp_vtable_clones() { assert(DumpSharedSpaces, "dump-time only"); // Layout (each slot is a intptr_t): // [number of slots in the first vtable = n1] // [ slots for the first vtable] // [number of slots in the first second = n2] // [ slots for the second vtable] // ... // The order of the vtables is the same as the CPP_VTAB_PATCH_TYPES_DO macro. CPP_VTABLE_PATCH_TYPES_DO(ALLOC_CPP_VTABLE_CLONE); } // Switch the vtable pointer to point to the cloned vtable. We assume the // vtable pointer is in first slot in object. void MetaspaceShared::patch_cpp_vtable_pointers() { int n = _global_klass_objects->length(); for (int i = 0; i < n; i++) { Klass* obj = _global_klass_objects->at(i); if (obj->is_instance_klass()) { InstanceKlass* ik = InstanceKlass::cast(obj); if (ik->is_class_loader_instance_klass()) { CppVtableCloner::patch(ik); } else if (ik->is_reference_instance_klass()) { CppVtableCloner::patch(ik); } else if (ik->is_mirror_instance_klass()) { CppVtableCloner::patch(ik); } else { CppVtableCloner::patch(ik); } ConstantPool* cp = ik->constants(); CppVtableCloner::patch(cp); for (int j = 0; j < ik->methods()->length(); j++) { Method* m = ik->methods()->at(j); CppVtableCloner::patch(m); assert(CppVtableCloner::is_valid_shared_object(m), "must be"); } } else if (obj->is_objArray_klass()) { CppVtableCloner::patch(obj); } else { assert(obj->is_typeArray_klass(), "sanity"); CppVtableCloner::patch(obj); } } } bool MetaspaceShared::is_valid_shared_method(const Method* m) { assert(is_in_shared_metaspace(m), "must be"); return CppVtableCloner::is_valid_shared_object(m); } // Closure for serializing initialization data out to a data area to be // written to the shared file. class WriteClosure : public SerializeClosure { private: DumpRegion* _dump_region; public: WriteClosure(DumpRegion* r) { _dump_region = r; } void do_ptr(void** p) { _dump_region->append_intptr_t((intptr_t)*p); } void do_u4(u4* p) { void* ptr = (void*)(uintx(*p)); do_ptr(&ptr); } void do_tag(int tag) { _dump_region->append_intptr_t((intptr_t)tag); } void do_oop(oop* o) { if (*o == NULL) { _dump_region->append_intptr_t(0); } else { assert(HeapShared::is_heap_object_archiving_allowed(), "Archiving heap object is not allowed"); _dump_region->append_intptr_t( (intptr_t)CompressedOops::encode_not_null(*o)); } } void do_region(u_char* start, size_t size) { assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment"); assert(size % sizeof(intptr_t) == 0, "bad size"); do_tag((int)size); while (size > 0) { _dump_region->append_intptr_t(*(intptr_t*)start); start += sizeof(intptr_t); size -= sizeof(intptr_t); } } bool reading() const { return false; } }; // This is for dumping detailed statistics for the allocations // in the shared spaces. class DumpAllocStats : public ResourceObj { public: // Here's poor man's enum inheritance #define SHAREDSPACE_OBJ_TYPES_DO(f) \ METASPACE_OBJ_TYPES_DO(f) \ f(SymbolHashentry) \ f(SymbolBucket) \ f(StringHashentry) \ f(StringBucket) \ f(Other) enum Type { // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc SHAREDSPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_DECLARE) _number_of_types }; static const char * type_name(Type type) { switch(type) { SHAREDSPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_NAME_CASE) default: ShouldNotReachHere(); return NULL; } } public: enum { RO = 0, RW = 1 }; int _counts[2][_number_of_types]; int _bytes [2][_number_of_types]; DumpAllocStats() { memset(_counts, 0, sizeof(_counts)); memset(_bytes, 0, sizeof(_bytes)); }; void record(MetaspaceObj::Type type, int byte_size, bool read_only) { assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity"); int which = (read_only) ? RO : RW; _counts[which][type] ++; _bytes [which][type] += byte_size; } void record_other_type(int byte_size, bool read_only) { int which = (read_only) ? RO : RW; _bytes [which][OtherType] += byte_size; } void print_stats(int ro_all, int rw_all, int mc_all, int md_all); }; void DumpAllocStats::print_stats(int ro_all, int rw_all, int mc_all, int md_all) { // Calculate size of data that was not allocated by Metaspace::allocate() MetaspaceSharedStats *stats = MetaspaceShared::stats(); // symbols _counts[RO][SymbolHashentryType] = stats->symbol.hashentry_count; _bytes [RO][SymbolHashentryType] = stats->symbol.hashentry_bytes; _counts[RO][SymbolBucketType] = stats->symbol.bucket_count; _bytes [RO][SymbolBucketType] = stats->symbol.bucket_bytes; // strings _counts[RO][StringHashentryType] = stats->string.hashentry_count; _bytes [RO][StringHashentryType] = stats->string.hashentry_bytes; _counts[RO][StringBucketType] = stats->string.bucket_count; _bytes [RO][StringBucketType] = stats->string.bucket_bytes; // TODO: count things like dictionary, vtable, etc _bytes[RW][OtherType] += mc_all + md_all; rw_all += mc_all + md_all; // mc/md are mapped Read/Write // prevent divide-by-zero if (ro_all < 1) { ro_all = 1; } if (rw_all < 1) { rw_all = 1; } int all_ro_count = 0; int all_ro_bytes = 0; int all_rw_count = 0; int all_rw_bytes = 0; // To make fmt_stats be a syntactic constant (for format warnings), use #define. #define fmt_stats "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f" const char *sep = "--------------------+---------------------------+---------------------------+--------------------------"; const char *hdr = " ro_cnt ro_bytes % | rw_cnt rw_bytes % | all_cnt all_bytes %"; LogMessage(cds) msg; msg.info("Detailed metadata info (excluding od/st regions; rw stats include md/mc regions):"); msg.info("%s", hdr); msg.info("%s", sep); for (int type = 0; type < int(_number_of_types); type ++) { const char *name = type_name((Type)type); int ro_count = _counts[RO][type]; int ro_bytes = _bytes [RO][type]; int rw_count = _counts[RW][type]; int rw_bytes = _bytes [RW][type]; int count = ro_count + rw_count; int bytes = ro_bytes + rw_bytes; double ro_perc = percent_of(ro_bytes, ro_all); double rw_perc = percent_of(rw_bytes, rw_all); double perc = percent_of(bytes, ro_all + rw_all); msg.info(fmt_stats, name, ro_count, ro_bytes, ro_perc, rw_count, rw_bytes, rw_perc, count, bytes, perc); all_ro_count += ro_count; all_ro_bytes += ro_bytes; all_rw_count += rw_count; all_rw_bytes += rw_bytes; } int all_count = all_ro_count + all_rw_count; int all_bytes = all_ro_bytes + all_rw_bytes; double all_ro_perc = percent_of(all_ro_bytes, ro_all); double all_rw_perc = percent_of(all_rw_bytes, rw_all); double all_perc = percent_of(all_bytes, ro_all + rw_all); msg.info("%s", sep); msg.info(fmt_stats, "Total", all_ro_count, all_ro_bytes, all_ro_perc, all_rw_count, all_rw_bytes, all_rw_perc, all_count, all_bytes, all_perc); assert(all_ro_bytes == ro_all, "everything should have been counted"); assert(all_rw_bytes == rw_all, "everything should have been counted"); #undef fmt_stats } // Populate the shared space. class VM_PopulateDumpSharedSpace: public VM_Operation { private: GrowableArray *_closed_archive_heap_regions; GrowableArray *_open_archive_heap_regions; GrowableArray *_closed_archive_heap_oopmaps; GrowableArray *_open_archive_heap_oopmaps; void dump_java_heap_objects() NOT_CDS_JAVA_HEAP_RETURN; void dump_archive_heap_oopmaps() NOT_CDS_JAVA_HEAP_RETURN; void dump_archive_heap_oopmaps(GrowableArray* regions, GrowableArray* oopmaps); void dump_symbols(); char* dump_read_only_tables(); void print_region_stats(); void print_heap_region_stats(GrowableArray *heap_mem, const char *name, const size_t total_size); public: VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; } void doit(); // outline because gdb sucks static void write_region(FileMapInfo* mapinfo, int region, DumpRegion* space, bool read_only, bool allow_exec); bool allow_nested_vm_operations() const { return true; } }; // class VM_PopulateDumpSharedSpace class SortedSymbolClosure: public SymbolClosure { GrowableArray _symbols; virtual void do_symbol(Symbol** sym) { assert((*sym)->is_permanent(), "archived symbols must be permanent"); _symbols.append(*sym); } static int compare_symbols_by_address(Symbol** a, Symbol** b) { if (a[0] < b[0]) { return -1; } else if (a[0] == b[0]) { return 0; } else { return 1; } } public: SortedSymbolClosure() { SymbolTable::symbols_do(this); _symbols.sort(compare_symbols_by_address); } GrowableArray* get_sorted_symbols() { return &_symbols; } }; // ArchiveCompactor -- // // This class is the central piece of shared archive compaction -- all metaspace data are // initially allocated outside of the shared regions. ArchiveCompactor copies the // metaspace data into their final location in the shared regions. class ArchiveCompactor : AllStatic { static DumpAllocStats* _alloc_stats; static SortedSymbolClosure* _ssc; typedef KVHashtable RelocationTable; static RelocationTable* _new_loc_table; public: static void initialize() { _alloc_stats = new(ResourceObj::C_HEAP, mtInternal)DumpAllocStats; _new_loc_table = new RelocationTable(8087); } static DumpAllocStats* alloc_stats() { return _alloc_stats; } // Use this when you allocate space with MetaspaceShare::read_only_space_alloc() // outside of ArchiveCompactor::allocate(). These are usually for misc tables // that are allocated in the RO space. class OtherROAllocMark { char* _oldtop; public: OtherROAllocMark() { _oldtop = _ro_region.top(); } ~OtherROAllocMark() { char* newtop = _ro_region.top(); ArchiveCompactor::alloc_stats()->record_other_type(int(newtop - _oldtop), true); } }; static void allocate(MetaspaceClosure::Ref* ref, bool read_only) { address obj = ref->obj(); int bytes = ref->size() * BytesPerWord; char* p; size_t alignment = BytesPerWord; char* oldtop; char* newtop; if (read_only) { oldtop = _ro_region.top(); p = _ro_region.allocate(bytes, alignment); newtop = _ro_region.top(); } else { oldtop = _rw_region.top(); if (ref->msotype() == MetaspaceObj::ClassType) { // Save a pointer immediate in front of an InstanceKlass, so // we can do a quick lookup from InstanceKlass* -> RunTimeSharedClassInfo* // without building another hashtable. See RunTimeSharedClassInfo::get_for() // in systemDictionaryShared.cpp. Klass* klass = (Klass*)obj; if (klass->is_instance_klass()) { SystemDictionaryShared::validate_before_archiving(InstanceKlass::cast(klass)); _rw_region.allocate(sizeof(address), BytesPerWord); } } p = _rw_region.allocate(bytes, alignment); newtop = _rw_region.top(); } memcpy(p, obj, bytes); assert(_new_loc_table->lookup(obj) == NULL, "each object can be relocated at most once"); _new_loc_table->add(obj, (address)p); log_trace(cds)("Copy: " PTR_FORMAT " ==> " PTR_FORMAT " %d", p2i(obj), p2i(p), bytes); if (_new_loc_table->maybe_grow()) { log_info(cds, hashtables)("Expanded _new_loc_table to %d", _new_loc_table->table_size()); } _alloc_stats->record(ref->msotype(), int(newtop - oldtop), read_only); } static address get_new_loc(MetaspaceClosure::Ref* ref) { address* pp = _new_loc_table->lookup(ref->obj()); assert(pp != NULL, "must be"); return *pp; } private: // Makes a shallow copy of visited MetaspaceObj's class ShallowCopier: public UniqueMetaspaceClosure { bool _read_only; public: ShallowCopier(bool read_only) : _read_only(read_only) {} virtual void do_unique_ref(Ref* ref, bool read_only) { if (read_only == _read_only) { allocate(ref, read_only); } } }; // Relocate embedded pointers within a MetaspaceObj's shallow copy class ShallowCopyEmbeddedRefRelocator: public UniqueMetaspaceClosure { public: virtual void do_unique_ref(Ref* ref, bool read_only) { address new_loc = get_new_loc(ref); RefRelocator refer; ref->metaspace_pointers_do_at(&refer, new_loc); } }; // Relocate a reference to point to its shallow copy class RefRelocator: public MetaspaceClosure { public: virtual bool do_ref(Ref* ref, bool read_only) { if (ref->not_null()) { ref->update(get_new_loc(ref)); } return false; // Do not recurse. } }; #ifdef ASSERT class IsRefInArchiveChecker: public MetaspaceClosure { public: virtual bool do_ref(Ref* ref, bool read_only) { if (ref->not_null()) { char* obj = (char*)ref->obj(); assert(_ro_region.contains(obj) || _rw_region.contains(obj), "must be relocated to point to CDS archive"); } return false; // Do not recurse. } }; #endif public: static void copy_and_compact() { ResourceMark rm; SortedSymbolClosure the_ssc; // StackObj _ssc = &the_ssc; tty->print_cr("Scanning all metaspace objects ... "); { // allocate and shallow-copy RW objects, immediately following the MC region tty->print_cr("Allocating RW objects ... "); _mc_region.pack(&_rw_region); ResourceMark rm; ShallowCopier rw_copier(false); iterate_roots(&rw_copier); } { // allocate and shallow-copy of RO object, immediately following the RW region tty->print_cr("Allocating RO objects ... "); _rw_region.pack(&_ro_region); ResourceMark rm; ShallowCopier ro_copier(true); iterate_roots(&ro_copier); } { tty->print_cr("Relocating embedded pointers ... "); ResourceMark rm; ShallowCopyEmbeddedRefRelocator emb_reloc; iterate_roots(&emb_reloc); } { tty->print_cr("Relocating external roots ... "); ResourceMark rm; RefRelocator ext_reloc; iterate_roots(&ext_reloc); } #ifdef ASSERT { tty->print_cr("Verifying external roots ... "); ResourceMark rm; IsRefInArchiveChecker checker; iterate_roots(&checker); } #endif // cleanup _ssc = NULL; } // We must relocate the System::_well_known_klasses only after we have copied the // java objects in during dump_java_heap_objects(): during the object copy, we operate on // old objects which assert that their klass is the original klass. static void relocate_well_known_klasses() { { tty->print_cr("Relocating SystemDictionary::_well_known_klasses[] ... "); ResourceMark rm; RefRelocator ext_reloc; SystemDictionary::well_known_klasses_do(&ext_reloc); } // NOTE: after this point, we shouldn't have any globals that can reach the old // objects. // We cannot use any of the objects in the heap anymore (except for the // shared strings) because their headers no longer point to valid Klasses. } static void iterate_roots(MetaspaceClosure* it) { GrowableArray* symbols = _ssc->get_sorted_symbols(); for (int i=0; ilength(); i++) { it->push(symbols->adr_at(i)); } if (_global_klass_objects != NULL) { // Need to fix up the pointers for (int i = 0; i < _global_klass_objects->length(); i++) { // NOTE -- this requires that the vtable is NOT yet patched, or else we are hosed. it->push(_global_klass_objects->adr_at(i)); } } FileMapInfo::metaspace_pointers_do(it); SystemDictionaryShared::dumptime_classes_do(it); Universe::metaspace_pointers_do(it); SymbolTable::metaspace_pointers_do(it); vmSymbols::metaspace_pointers_do(it); } static Klass* get_relocated_klass(Klass* orig_klass) { assert(DumpSharedSpaces, "dump time only"); address* pp = _new_loc_table->lookup((address)orig_klass); assert(pp != NULL, "must be"); Klass* klass = (Klass*)(*pp); assert(klass->is_klass(), "must be"); return klass; } }; DumpAllocStats* ArchiveCompactor::_alloc_stats; SortedSymbolClosure* ArchiveCompactor::_ssc; ArchiveCompactor::RelocationTable* ArchiveCompactor::_new_loc_table; void VM_PopulateDumpSharedSpace::write_region(FileMapInfo* mapinfo, int region_idx, DumpRegion* dump_region, bool read_only, bool allow_exec) { mapinfo->write_region(region_idx, dump_region->base(), dump_region->used(), read_only, allow_exec); } void VM_PopulateDumpSharedSpace::dump_symbols() { tty->print_cr("Dumping symbol table ..."); NOT_PRODUCT(SymbolTable::verify()); SymbolTable::write_to_archive(); } char* VM_PopulateDumpSharedSpace::dump_read_only_tables() { ArchiveCompactor::OtherROAllocMark mark; tty->print("Removing java_mirror ... "); if (!HeapShared::is_heap_object_archiving_allowed()) { clear_basic_type_mirrors(); } remove_java_mirror_in_classes(); tty->print_cr("done. "); SystemDictionaryShared::write_to_archive(); char* start = _ro_region.top(); // Write the other data to the output array. WriteClosure wc(&_ro_region); MetaspaceShared::serialize(&wc); // Write the bitmaps for patching the archive heap regions dump_archive_heap_oopmaps(); return start; } void VM_PopulateDumpSharedSpace::doit() { // We should no longer allocate anything from the metaspace, so that: // // (1) Metaspace::allocate might trigger GC if we have run out of // committed metaspace, but we can't GC because we're running // in the VM thread. // (2) ArchiveCompactor needs to work with a stable set of MetaspaceObjs. Metaspace::freeze(); Thread* THREAD = VMThread::vm_thread(); FileMapInfo::check_nonempty_dir_in_shared_path_table(); 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"); guarantee(SystemDictionary::placeholders()->number_of_entries() == 0, "placeholders are not saved"); // At this point, many classes have been loaded. // Gather systemDictionary classes in a global array and do everything to // that so we don't have to walk the SystemDictionary again. SystemDictionaryShared::check_excluded_classes(); _global_klass_objects = new GrowableArray(1000); CollectClassesClosure collect_classes; ClassLoaderDataGraph::loaded_classes_do(&collect_classes); tty->print_cr("Number of classes %d", _global_klass_objects->length()); { int num_type_array = 0, num_obj_array = 0, num_inst = 0; for (int i = 0; i < _global_klass_objects->length(); i++) { Klass* k = _global_klass_objects->at(i); if (k->is_instance_klass()) { num_inst ++; } else if (k->is_objArray_klass()) { num_obj_array ++; } else { assert(k->is_typeArray_klass(), "sanity"); num_type_array ++; } } tty->print_cr(" instance classes = %5d", num_inst); tty->print_cr(" obj array classes = %5d", num_obj_array); tty->print_cr(" type array classes = %5d", num_type_array); } // Ensure the ConstMethods won't be modified at run-time tty->print("Updating ConstMethods ... "); rewrite_nofast_bytecodes_and_calculate_fingerprints(); tty->print_cr("done. "); // Remove all references outside the metadata tty->print("Removing unshareable information ... "); remove_unshareable_in_classes(); tty->print_cr("done. "); ArchiveCompactor::initialize(); ArchiveCompactor::copy_and_compact(); dump_symbols(); // Dump supported java heap objects _closed_archive_heap_regions = NULL; _open_archive_heap_regions = NULL; dump_java_heap_objects(); ArchiveCompactor::relocate_well_known_klasses(); char* read_only_tables_start = dump_read_only_tables(); _ro_region.pack(&_md_region); char* vtbl_list = _md_region.top(); MetaspaceShared::allocate_cpp_vtable_clones(); _md_region.pack(&_od_region); // Relocate the archived class file data into the od region relocate_cached_class_file(); _od_region.pack(); // The 5 core spaces are allocated consecutively mc->rw->ro->md->od, so there total size // is just the spaces between the two ends. size_t core_spaces_size = _od_region.end() - _mc_region.base(); assert(core_spaces_size == (size_t)align_up(core_spaces_size, Metaspace::reserve_alignment()), "should already be aligned"); // During patching, some virtual methods may be called, so at this point // the vtables must contain valid methods (as filled in by CppVtableCloner::allocate). MetaspaceShared::patch_cpp_vtable_pointers(); // The vtable clones contain addresses of the current process. // We don't want to write these addresses into the archive. MetaspaceShared::zero_cpp_vtable_clones_for_writing(); // Create and write the archive file that maps the shared spaces. FileMapInfo* mapinfo = new FileMapInfo(); mapinfo->populate_header(os::vm_allocation_granularity()); mapinfo->set_read_only_tables_start(read_only_tables_start); mapinfo->set_misc_data_patching_start(vtbl_list); mapinfo->set_cds_i2i_entry_code_buffers(MetaspaceShared::cds_i2i_entry_code_buffers()); mapinfo->set_cds_i2i_entry_code_buffers_size(MetaspaceShared::cds_i2i_entry_code_buffers_size()); mapinfo->set_core_spaces_size(core_spaces_size); for (int pass=1; pass<=2; pass++) { bool print_archive_log = (pass==1); if (pass == 1) { // The first pass doesn't actually write the data to disk. All it // does is to update the fields in the mapinfo->_header. } else { // After the first pass, the contents of mapinfo->_header are finalized, // so we can compute the header's CRC, and write the contents of the header // and the regions into disk. mapinfo->open_for_write(); mapinfo->set_header_crc(mapinfo->compute_header_crc()); } mapinfo->write_header(); // NOTE: md contains the trampoline code for method entries, which are patched at run time, // so it needs to be read/write. write_region(mapinfo, MetaspaceShared::mc, &_mc_region, /*read_only=*/false,/*allow_exec=*/true); write_region(mapinfo, MetaspaceShared::rw, &_rw_region, /*read_only=*/false,/*allow_exec=*/false); write_region(mapinfo, MetaspaceShared::ro, &_ro_region, /*read_only=*/true, /*allow_exec=*/false); write_region(mapinfo, MetaspaceShared::md, &_md_region, /*read_only=*/false,/*allow_exec=*/false); write_region(mapinfo, MetaspaceShared::od, &_od_region, /*read_only=*/true, /*allow_exec=*/false); _total_closed_archive_region_size = mapinfo->write_archive_heap_regions( _closed_archive_heap_regions, _closed_archive_heap_oopmaps, MetaspaceShared::first_closed_archive_heap_region, MetaspaceShared::max_closed_archive_heap_region, print_archive_log); _total_open_archive_region_size = mapinfo->write_archive_heap_regions( _open_archive_heap_regions, _open_archive_heap_oopmaps, MetaspaceShared::first_open_archive_heap_region, MetaspaceShared::max_open_archive_heap_region, print_archive_log); } mapinfo->close(); // Restore the vtable in case we invoke any virtual methods. MetaspaceShared::clone_cpp_vtables((intptr_t*)vtbl_list); print_region_stats(); if (log_is_enabled(Info, cds)) { ArchiveCompactor::alloc_stats()->print_stats(int(_ro_region.used()), int(_rw_region.used()), int(_mc_region.used()), int(_md_region.used())); } if (PrintSystemDictionaryAtExit) { SystemDictionary::print(); } // There may be other pending VM operations that operate on the InstanceKlasses, // which will fail because InstanceKlasses::remove_unshareable_info() // has been called. Forget these operations and exit the VM directly. vm_direct_exit(0); } void VM_PopulateDumpSharedSpace::print_region_stats() { // Print statistics of all the regions const size_t total_reserved = _ro_region.reserved() + _rw_region.reserved() + _mc_region.reserved() + _md_region.reserved() + _od_region.reserved() + _total_closed_archive_region_size + _total_open_archive_region_size; const size_t total_bytes = _ro_region.used() + _rw_region.used() + _mc_region.used() + _md_region.used() + _od_region.used() + _total_closed_archive_region_size + _total_open_archive_region_size; const double total_u_perc = percent_of(total_bytes, total_reserved); _mc_region.print(total_reserved); _rw_region.print(total_reserved); _ro_region.print(total_reserved); _md_region.print(total_reserved); _od_region.print(total_reserved); print_heap_region_stats(_closed_archive_heap_regions, "ca", total_reserved); print_heap_region_stats(_open_archive_heap_regions, "oa", total_reserved); tty->print_cr("total : " SIZE_FORMAT_W(9) " [100.0%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used]", total_bytes, total_reserved, total_u_perc); } void VM_PopulateDumpSharedSpace::print_heap_region_stats(GrowableArray *heap_mem, const char *name, const size_t total_size) { int arr_len = heap_mem == NULL ? 0 : heap_mem->length(); for (int i = 0; i < arr_len; i++) { char* start = (char*)heap_mem->at(i).start(); size_t size = heap_mem->at(i).byte_size(); char* top = start + size; tty->print_cr("%s%d space: " SIZE_FORMAT_W(9) " [ %4.1f%% of total] out of " SIZE_FORMAT_W(9) " bytes [100.0%% used] at " INTPTR_FORMAT, name, i, size, size/double(total_size)*100.0, size, p2i(start)); } } // Update a Java object to point its Klass* to the new location after // shared archive has been compacted. void MetaspaceShared::relocate_klass_ptr(oop o) { assert(DumpSharedSpaces, "sanity"); Klass* k = ArchiveCompactor::get_relocated_klass(o->klass()); o->set_klass(k); } Klass* MetaspaceShared::get_relocated_klass(Klass *k) { assert(DumpSharedSpaces, "sanity"); return ArchiveCompactor::get_relocated_klass(k); } class LinkSharedClassesClosure : public KlassClosure { Thread* THREAD; bool _made_progress; public: LinkSharedClassesClosure(Thread* thread) : THREAD(thread), _made_progress(false) {} void reset() { _made_progress = false; } bool made_progress() const { return _made_progress; } void do_klass(Klass* k) { if (k->is_instance_klass()) { InstanceKlass* ik = InstanceKlass::cast(k); // Link the class to cause the bytecodes to be rewritten and the // cpcache to be created. Class verification is done according // to -Xverify setting. _made_progress |= MetaspaceShared::try_link_class(ik, THREAD); guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class"); ik->constants()->resolve_class_constants(THREAD); } } }; class CheckSharedClassesClosure : public KlassClosure { bool _made_progress; public: CheckSharedClassesClosure() : _made_progress(false) {} void reset() { _made_progress = false; } bool made_progress() const { return _made_progress; } void do_klass(Klass* k) { if (k->is_instance_klass() && InstanceKlass::cast(k)->check_sharing_error_state()) { _made_progress = true; } } }; void MetaspaceShared::link_and_cleanup_shared_classes(TRAPS) { // We need to iterate because verification may cause additional classes // to be loaded. LinkSharedClassesClosure link_closure(THREAD); do { link_closure.reset(); ClassLoaderDataGraph::unlocked_loaded_classes_do(&link_closure); guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class"); } while (link_closure.made_progress()); if (_has_error_classes) { // Mark all classes whose super class or interfaces failed verification. CheckSharedClassesClosure check_closure; do { // Not completely sure if we need to do this iteratively. Anyway, // we should come here only if there are unverifiable classes, which // shouldn't happen in normal cases. So better safe than sorry. check_closure.reset(); ClassLoaderDataGraph::unlocked_loaded_classes_do(&check_closure); } while (check_closure.made_progress()); } } void MetaspaceShared::prepare_for_dumping() { Arguments::check_unsupported_dumping_properties(); ClassLoader::initialize_shared_path(); } // Preload classes from a list, populate the shared spaces and dump to a // file. void MetaspaceShared::preload_and_dump(TRAPS) { { TraceTime timer("Dump Shared Spaces", TRACETIME_LOG(Info, startuptime)); ResourceMark rm; char class_list_path_str[JVM_MAXPATHLEN]; // Preload classes to be shared. // Should use some os:: method rather than fopen() here. aB. const char* class_list_path; if (SharedClassListFile == NULL) { // 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) os::jvm_path(class_list_path_str, sizeof(class_list_path_str)); for (int i = 0; i < 3; i++) { char *end = strrchr(class_list_path_str, *os::file_separator()); if (end != NULL) *end = '\0'; } int class_list_path_len = (int)strlen(class_list_path_str); if (class_list_path_len >= 3) { if (strcmp(class_list_path_str + class_list_path_len - 3, "lib") != 0) { if (class_list_path_len < JVM_MAXPATHLEN - 4) { jio_snprintf(class_list_path_str + class_list_path_len, sizeof(class_list_path_str) - class_list_path_len, "%slib", os::file_separator()); class_list_path_len += 4; } } } if (class_list_path_len < JVM_MAXPATHLEN - 10) { jio_snprintf(class_list_path_str + class_list_path_len, sizeof(class_list_path_str) - class_list_path_len, "%sclasslist", os::file_separator()); } class_list_path = class_list_path_str; } else { class_list_path = SharedClassListFile; } tty->print_cr("Loading classes to share ..."); _has_error_classes = false; int class_count = preload_classes(class_list_path, THREAD); if (ExtraSharedClassListFile) { class_count += preload_classes(ExtraSharedClassListFile, THREAD); } tty->print_cr("Loading classes to share: done."); log_info(cds)("Shared spaces: preloaded %d classes", class_count); if (SharedArchiveConfigFile) { tty->print_cr("Reading extra data from %s ...", SharedArchiveConfigFile); read_extra_data(SharedArchiveConfigFile, THREAD); } tty->print_cr("Reading extra data: done."); HeapShared::init_subgraph_entry_fields(THREAD); // Rewrite and link classes tty->print_cr("Rewriting and linking classes ..."); // Link any classes which got missed. This would happen if we have loaded classes that // were not explicitly specified in the classlist. E.g., if an interface implemented by class K // fails verification, all other interfaces that were not specified in the classlist but // are implemented by K are not verified. link_and_cleanup_shared_classes(CATCH); tty->print_cr("Rewriting and linking classes: done"); VM_PopulateDumpSharedSpace op; VMThread::execute(&op); } } int MetaspaceShared::preload_classes(const char* class_list_path, TRAPS) { ClassListParser parser(class_list_path); int class_count = 0; while (parser.parse_one_line()) { Klass* klass = parser.load_current_class(THREAD); if (HAS_PENDING_EXCEPTION) { if (klass == NULL && (PENDING_EXCEPTION->klass()->name() == vmSymbols::java_lang_ClassNotFoundException())) { // print a warning only when the pending exception is class not found tty->print_cr("Preload Warning: Cannot find %s", parser.current_class_name()); } CLEAR_PENDING_EXCEPTION; } if (klass != NULL) { if (log_is_enabled(Trace, cds)) { ResourceMark rm; log_trace(cds)("Shared spaces preloaded: %s", klass->external_name()); } if (klass->is_instance_klass()) { InstanceKlass* ik = InstanceKlass::cast(klass); // 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 and // cpCache) are located together. try_link_class(ik, THREAD); guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class"); } class_count++; } } return class_count; } // Returns true if the class's status has changed bool MetaspaceShared::try_link_class(InstanceKlass* ik, TRAPS) { assert(DumpSharedSpaces, "should only be called during dumping"); if (ik->init_state() < InstanceKlass::linked) { bool saved = BytecodeVerificationLocal; if (ik->loader_type() == 0 && ik->class_loader() == NULL) { // The verification decision is based on BytecodeVerificationRemote // for non-system classes. Since we are using the NULL classloader // to load non-system classes for customized class loaders during dumping, // we need to temporarily change BytecodeVerificationLocal to be the same as // BytecodeVerificationRemote. Note this can cause the parent system // classes also being verified. The extra overhead is acceptable during // dumping. BytecodeVerificationLocal = BytecodeVerificationRemote; } ik->link_class(THREAD); if (HAS_PENDING_EXCEPTION) { ResourceMark rm; tty->print_cr("Preload Warning: Verification failed for %s", ik->external_name()); CLEAR_PENDING_EXCEPTION; ik->set_in_error_state(); _has_error_classes = true; } BytecodeVerificationLocal = saved; return true; } else { return false; } } #if INCLUDE_CDS_JAVA_HEAP void VM_PopulateDumpSharedSpace::dump_java_heap_objects() { // The closed and open archive heap space has maximum two regions. // See FileMapInfo::write_archive_heap_regions() for details. _closed_archive_heap_regions = new GrowableArray(2); _open_archive_heap_regions = new GrowableArray(2); HeapShared::archive_java_heap_objects(_closed_archive_heap_regions, _open_archive_heap_regions); ArchiveCompactor::OtherROAllocMark mark; HeapShared::write_subgraph_info_table(); } void VM_PopulateDumpSharedSpace::dump_archive_heap_oopmaps() { if (HeapShared::is_heap_object_archiving_allowed()) { _closed_archive_heap_oopmaps = new GrowableArray(2); dump_archive_heap_oopmaps(_closed_archive_heap_regions, _closed_archive_heap_oopmaps); _open_archive_heap_oopmaps = new GrowableArray(2); dump_archive_heap_oopmaps(_open_archive_heap_regions, _open_archive_heap_oopmaps); } } void VM_PopulateDumpSharedSpace::dump_archive_heap_oopmaps(GrowableArray* regions, GrowableArray* oopmaps) { for (int i=0; ilength(); i++) { ResourceBitMap oopmap = HeapShared::calculate_oopmap(regions->at(i)); size_t size_in_bits = oopmap.size(); size_t size_in_bytes = oopmap.size_in_bytes(); uintptr_t* buffer = (uintptr_t*)_ro_region.allocate(size_in_bytes, sizeof(intptr_t)); oopmap.write_to(buffer, size_in_bytes); log_info(cds)("Oopmap = " INTPTR_FORMAT " (" SIZE_FORMAT_W(6) " bytes) for heap region " INTPTR_FORMAT " (" SIZE_FORMAT_W(8) " bytes)", p2i(buffer), size_in_bytes, p2i(regions->at(i).start()), regions->at(i).byte_size()); ArchiveHeapOopmapInfo info; info._oopmap = (address)buffer; info._oopmap_size_in_bits = size_in_bits; oopmaps->append(info); } } #endif // INCLUDE_CDS_JAVA_HEAP // Closure for serializing initialization data in from a data area // (ptr_array) read from the shared file. class ReadClosure : public SerializeClosure { private: intptr_t** _ptr_array; inline intptr_t nextPtr() { return *(*_ptr_array)++; } public: ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; } void do_ptr(void** p) { assert(*p == NULL, "initializing previous initialized pointer."); intptr_t obj = nextPtr(); assert((intptr_t)obj >= 0 || (intptr_t)obj < -100, "hit tag while initializing ptrs."); *p = (void*)obj; } void do_u4(u4* p) { intptr_t obj = nextPtr(); *p = (u4)(uintx(obj)); } void do_tag(int tag) { int old_tag; old_tag = (int)(intptr_t)nextPtr(); // do_int(&old_tag); assert(tag == old_tag, "old tag doesn't match"); FileMapInfo::assert_mark(tag == old_tag); } void do_oop(oop *p) { narrowOop o = (narrowOop)nextPtr(); if (o == 0 || !HeapShared::open_archive_heap_region_mapped()) { p = NULL; } else { assert(HeapShared::is_heap_object_archiving_allowed(), "Archived heap object is not allowed"); assert(HeapShared::open_archive_heap_region_mapped(), "Open archive heap region is not mapped"); *p = HeapShared::decode_from_archive(o); } } void do_region(u_char* start, size_t size) { assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment"); assert(size % sizeof(intptr_t) == 0, "bad size"); do_tag((int)size); while (size > 0) { *(intptr_t*)start = nextPtr(); start += sizeof(intptr_t); size -= sizeof(intptr_t); } } bool reading() const { return true; } }; // Return true if given address is in the misc data region bool MetaspaceShared::is_in_shared_region(const void* p, int idx) { return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_region(p, idx); } bool MetaspaceShared::is_in_trampoline_frame(address addr) { if (UseSharedSpaces && is_in_shared_region(addr, MetaspaceShared::mc)) { return true; } return false; } // Map shared spaces at requested addresses and return if succeeded. bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) { size_t image_alignment = mapinfo->alignment(); #ifndef _WINDOWS // Map in the shared memory and then map the regions on top of it. // On Windows, don't map the memory here because it will cause the // mappings of the regions to fail. ReservedSpace shared_rs = mapinfo->reserve_shared_memory(); if (!shared_rs.is_reserved()) return false; #endif assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces"); char* ro_base = NULL; char* ro_top; char* rw_base = NULL; char* rw_top; char* mc_base = NULL; char* mc_top; char* md_base = NULL; char* md_top; char* od_base = NULL; char* od_top; // Map each shared region if ((mc_base = mapinfo->map_region(mc, &mc_top)) != NULL && (rw_base = mapinfo->map_region(rw, &rw_top)) != NULL && (ro_base = mapinfo->map_region(ro, &ro_top)) != NULL && (md_base = mapinfo->map_region(md, &md_top)) != NULL && (od_base = mapinfo->map_region(od, &od_top)) != NULL && (image_alignment == (size_t)os::vm_allocation_granularity()) && mapinfo->validate_shared_path_table()) { // Success -- set up MetaspaceObj::_shared_metaspace_{base,top} for // fast checking in MetaspaceShared::is_in_shared_metaspace() and // MetaspaceObj::is_shared(). // // We require that mc->rw->ro->md->od to be laid out consecutively, with no // gaps between them. That way, we can ensure that the OS won't be able to // allocate any new memory spaces inside _shared_metaspace_{base,top}, which // would mess up the simple comparision in MetaspaceShared::is_in_shared_metaspace(). assert(mc_base < ro_base && mc_base < rw_base && mc_base < md_base && mc_base < od_base, "must be"); assert(od_top > ro_top && od_top > rw_top && od_top > md_top && od_top > mc_top , "must be"); assert(mc_top == rw_base, "must be"); assert(rw_top == ro_base, "must be"); assert(ro_top == md_base, "must be"); assert(md_top == od_base, "must be"); _core_spaces_size = mapinfo->core_spaces_size(); MetaspaceObj::set_shared_metaspace_range((void*)mc_base, (void*)od_top); return true; } else { // If there was a failure in mapping any of the spaces, unmap the ones // that succeeded if (ro_base != NULL) mapinfo->unmap_region(ro); if (rw_base != NULL) mapinfo->unmap_region(rw); if (mc_base != NULL) mapinfo->unmap_region(mc); if (md_base != NULL) mapinfo->unmap_region(md); if (od_base != NULL) mapinfo->unmap_region(od); #ifndef _WINDOWS // Release the entire mapped region shared_rs.release(); #endif // If -Xshare:on is specified, print out the error message and exit VM, // otherwise, set UseSharedSpaces to false and continue. if (RequireSharedSpaces || PrintSharedArchiveAndExit) { vm_exit_during_initialization("Unable to use shared archive.", "Failed map_region for using -Xshare:on."); } else { FLAG_SET_DEFAULT(UseSharedSpaces, false); } return false; } } // Read the miscellaneous data from the shared file, and // serialize it out to its various destinations. void MetaspaceShared::initialize_shared_spaces() { FileMapInfo *mapinfo = FileMapInfo::current_info(); _cds_i2i_entry_code_buffers = mapinfo->cds_i2i_entry_code_buffers(); _cds_i2i_entry_code_buffers_size = mapinfo->cds_i2i_entry_code_buffers_size(); // _core_spaces_size is loaded from the shared archive immediatelly after mapping assert(_core_spaces_size == mapinfo->core_spaces_size(), "sanity"); char* buffer = mapinfo->misc_data_patching_start(); clone_cpp_vtables((intptr_t*)buffer); // The rest of the data is now stored in the RW region buffer = mapinfo->read_only_tables_start(); // Verify various attributes of the archive, plus initialize the // shared string/symbol tables intptr_t* array = (intptr_t*)buffer; ReadClosure rc(&array); serialize(&rc); // Initialize the run-time symbol table. SymbolTable::create_table(); mapinfo->patch_archived_heap_embedded_pointers(); // Close the mapinfo file mapinfo->close(); if (PrintSharedArchiveAndExit) { if (PrintSharedDictionary) { tty->print_cr("\nShared classes:\n"); SystemDictionaryShared::print_on(tty); } if (_archive_loading_failed) { tty->print_cr("archive is invalid"); vm_exit(1); } else { tty->print_cr("archive is valid"); vm_exit(0); } } } // JVM/TI RedefineClasses() support: bool MetaspaceShared::remap_shared_readonly_as_readwrite() { assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); if (UseSharedSpaces) { // remap the shared readonly space to shared readwrite, private FileMapInfo* mapinfo = FileMapInfo::current_info(); if (!mapinfo->remap_shared_readonly_as_readwrite()) { return false; } _remapped_readwrite = true; } return true; } void MetaspaceShared::report_out_of_space(const char* name, size_t needed_bytes) { // This is highly unlikely to happen on 64-bits because we have reserved a 4GB space. // On 32-bit we reserve only 256MB so you could run out of space with 100,000 classes // or so. _mc_region.print_out_of_space_msg(name, needed_bytes); _rw_region.print_out_of_space_msg(name, needed_bytes); _ro_region.print_out_of_space_msg(name, needed_bytes); _md_region.print_out_of_space_msg(name, needed_bytes); _od_region.print_out_of_space_msg(name, needed_bytes); vm_exit_during_initialization(err_msg("Unable to allocate from '%s' region", name), "Please reduce the number of shared classes."); }