/* * Copyright (c) 2012, 2017, 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/classListParser.hpp" #include "classfile/classLoaderExt.hpp" #include "classfile/dictionary.hpp" #include "classfile/loaderConstraints.hpp" #include "classfile/placeholders.hpp" #include "classfile/sharedClassUtil.hpp" #include "classfile/symbolTable.hpp" #include "classfile/systemDictionary.hpp" #include "classfile/systemDictionaryShared.hpp" #include "code/codeCache.hpp" #include "gc/shared/gcLocker.hpp" #include "interpreter/bytecodeStream.hpp" #include "interpreter/bytecodes.hpp" #include "logging/log.hpp" #include "logging/logMessage.hpp" #include "memory/filemap.hpp" #include "memory/metaspace.hpp" #include "memory/metaspaceShared.hpp" #include "memory/resourceArea.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/jvm.h" #include "prims/jvmtiRedefineClasses.hpp" #include "runtime/timerTrace.hpp" #include "runtime/os.hpp" #include "runtime/signature.hpp" #include "runtime/vmThread.hpp" #include "runtime/vm_operations.hpp" #include "utilities/align.hpp" #include "utilities/defaultStream.hpp" #include "utilities/hashtable.inline.hpp" #include "memory/metaspaceClosure.hpp" 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) // // s0 - shared strings #0 // s1 - shared strings #1 (may be empty) // // Except for the s0/s1 regions, the other 5 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 regions are populated inside MetaspaceShared::dump_string_and_symbols. 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(); } 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; } double perc(size_t used, size_t total) const { if (total == 0) { total = 1; } return used / double(total) * 100.0; } void print(size_t total_bytes) const { tty->print_cr("%s space: " SIZE_FORMAT_W(9) " [ %4.1f%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used] at " INTPTR_FORMAT, _name, used(), perc(used(), total_bytes), reserved(), perc(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"); DumpRegion _s0_region("s0"), _s1_region("s1"); 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); } void MetaspaceShared::initialize_shared_rs() { 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 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()); if (UseAOT || cds_total > UnscaledClassSpaceMax) { // AOT forces narrow_klass_shift=LogKlassAlignmentInBytes Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes); } else { Universe::set_narrow_klass_shift(0); } Metaspace::initialize_class_space(tmp_class_space); tty->print_cr("narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d", p2i(Universe::narrow_klass_base()), Universe::narrow_klass_shift()); tty->print_cr("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); tty->print_cr("Allocated shared space: " SIZE_FORMAT " bytes at " PTR_FORMAT, _shared_rs.size(), p2i(_shared_rs.base())); } 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, true); soc->do_tag(--tag); // Dump/restore references to commonly used names and signatures. vmSymbols::serialize(soc); soc->do_tag(--tag); // Dump/restore the symbol and string tables SymbolTable::serialize(soc); StringTable::serialize(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; class CollectClassesClosure : public KlassClosure { void do_klass(Klass* k) { if (!(k->is_instance_klass() && InstanceKlass::cast(k)->is_in_error_state())) { _global_klass_objects->append_if_missing(k); } } }; static void remove_unshareable_in_classes() { for (int i = 0; i < _global_klass_objects->length(); i++) { Klass* k = _global_klass_objects->at(i); k->remove_unshareable_info(); } } static void rewrite_nofast_bytecode(Method* method) { RawBytecodeStream bcs(method); while (!bcs.is_last_bytecode()) { Bytecodes::Code opcode = bcs.raw_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_space(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_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 %"; ResourceMark rm; LogMessage(cds) msg; stringStream info_stream; info_stream.print_cr("Detailed metadata info (excluding od/st regions; rw stats include md/mc regions):"); info_stream.print_cr("%s", hdr); info_stream.print_cr("%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 = 100.0 * double(ro_bytes) / double(ro_all); double rw_perc = 100.0 * double(rw_bytes) / double(rw_all); double perc = 100.0 * double(bytes) / double(ro_all + rw_all); info_stream.print_cr(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 = 100.0 * double(all_ro_bytes) / double(ro_all); double all_rw_perc = 100.0 * double(all_rw_bytes) / double(rw_all); double all_perc = 100.0 * double(all_bytes) / double(ro_all + rw_all); info_stream.print_cr("%s", sep); info_stream.print_cr(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"); msg.info("%s", info_stream.as_string()); #undef fmt_stats } // Populate the shared space. class VM_PopulateDumpSharedSpace: public VM_Operation { private: GrowableArray *_string_regions; void dump_string_and_symbols(); char* dump_read_only_tables(); void print_region_stats(); 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); }; // 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; static unsigned my_hash(const address& a) { return primitive_hash
(a); } static bool my_equals(const address& a0, const address& a1) { return primitive_equals
(a0, a1); } typedef ResourceHashtable< address, address, ArchiveCompactor::my_hash, // solaris compiler doesn't like: primitive_hash
ArchiveCompactor::my_equals, // solaris compiler doesn't like: primitive_equals
16384, ResourceObj::C_HEAP> RelocationTable; static RelocationTable* _new_loc_table; public: static void initialize() { _alloc_stats = new(ResourceObj::C_HEAP, mtInternal)DumpAllocStats; _new_loc_table = new(ResourceObj::C_HEAP, mtInternal)RelocationTable; } static DumpAllocStats* alloc_stats() { return _alloc_stats; } 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(); p = _rw_region.allocate(bytes, alignment); newtop = _rw_region.top(); } memcpy(p, obj, bytes); bool isnew = _new_loc_table->put(obj, (address)p); assert(isnew, "must be"); log_trace(cds)("Copy: " PTR_FORMAT " ==> " PTR_FORMAT " %d", p2i(obj), p2i(p), bytes); _alloc_stats->record(ref->msotype(), int(newtop - oldtop), read_only); if (ref->msotype() == MetaspaceObj::SymbolType) { uintx delta = MetaspaceShared::object_delta(p); 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 Symbols and would require // millions of shared classes. vm_exit_during_initialization("Too many Symbols in the CDS archive", "Please reduce the number of shared classes."); } } } static address get_new_loc(MetaspaceClosure::Ref* ref) { address* pp = _new_loc_table->get(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() { // We should no longer allocate anything from the metaspace, so that // we can have a stable set of MetaspaceObjs to work with. Metaspace::freeze(); 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 // strings in during dump_string_and_symbols(): during the string copy, we operate on old // String objects which assert that their klass is the old // SystemDictionary::String_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 objects // in the CDS shared string regions) 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); SystemDictionary::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) { address* pp = _new_loc_table->get((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_string_and_symbols() { tty->print_cr("Dumping string and symbol tables ..."); NOT_PRODUCT(SymbolTable::verify()); NOT_PRODUCT(StringTable::verify()); SymbolTable::write_to_archive(); // The string space has maximum two regions. See FileMapInfo::write_string_regions() for details. _string_regions = new GrowableArray(2); StringTable::write_to_archive(_string_regions); } char* VM_PopulateDumpSharedSpace::dump_read_only_tables() { char* oldtop = _ro_region.top(); // Reorder the system dictionary. Moving the symbols affects // how the hash table indices are calculated. SystemDictionary::reorder_dictionary_for_sharing(); NOT_PRODUCT(SystemDictionary::verify();) size_t buckets_bytes = SystemDictionary::count_bytes_for_buckets(); char* buckets_top = _ro_region.allocate(buckets_bytes, sizeof(intptr_t)); SystemDictionary::copy_buckets(buckets_top, _ro_region.top()); size_t table_bytes = SystemDictionary::count_bytes_for_table(); char* table_top = _ro_region.allocate(table_bytes, sizeof(intptr_t)); SystemDictionary::copy_table(table_top, _ro_region.top()); // Write the other data to the output array. WriteClosure wc(&_ro_region); MetaspaceShared::serialize(&wc); char* newtop = _ro_region.top(); ArchiveCompactor::alloc_stats()->record_other_type(int(newtop - oldtop), true); return buckets_top; } void VM_PopulateDumpSharedSpace::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"); guarantee(SystemDictionary::placeholders()->number_of_entries() == 0, "placeholders 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"); // 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. _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_string_and_symbols(); 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); char* s0_start, *s0_top, *s0_end; char* s1_start, *s1_top, *s1_end; for (int pass=1; pass<=2; pass++) { 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); mapinfo->write_string_regions(_string_regions, &s0_start, &s0_top, &s0_end, &s1_start, &s1_top, &s1_end); } mapinfo->close(); // Restore the vtable in case we invoke any virtual methods. MetaspaceShared::clone_cpp_vtables((intptr_t*)vtbl_list); _s0_region.init(s0_start, s0_top, s0_end); _s1_region.init(s1_start, s1_top, s1_end); 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())); } } 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() + _s0_region.reserved() + _s1_region.reserved(); const size_t total_bytes = _ro_region.used() + _rw_region.used() + _mc_region.used() + _md_region.used() + _od_region.used() + _s0_region.used() + _s1_region.used(); const double total_u_perc = total_bytes / double(total_reserved) * 100.0; _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); _s0_region.print(total_reserved); _s1_region.print(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); } // 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); } 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"); } } }; 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::check_shared_class_loader_type(Klass* k) { if (k->is_instance_klass()) { InstanceKlass* ik = InstanceKlass::cast(k); u2 loader_type = ik->loader_type(); ResourceMark rm; guarantee(loader_type != 0, "Class loader type is not set for this class %s", ik->name()->as_C_string()); } } 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::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::loaded_classes_do(&check_closure); } while (check_closure.made_progress()); if (IgnoreUnverifiableClassesDuringDump) { // This is useful when running JCK or SQE tests. You should not // enable this when running real apps. SystemDictionary::remove_classes_in_error_state(); } else { tty->print_cr("Please remove the unverifiable classes from your class list and try again"); exit(1); } } // Copy the verification constraints from C_HEAP-alloced GrowableArrays to RO-alloced // Arrays SystemDictionaryShared::finalize_verification_constraints(); } void MetaspaceShared::prepare_for_dumping() { Arguments::check_unsupported_dumping_properties(); ClassLoader::initialize_shared_path(); FileMapInfo::allocate_classpath_entry_table(); } // 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); // 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); } if (PrintSystemDictionaryAtExit) { SystemDictionary::print(); } // Since various initialization steps have been undone by this process, // it is not reasonable to continue running a java process. exit(0); } 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 = ClassLoaderExt::load_one_class(&parser, THREAD); CLEAR_PENDING_EXCEPTION; if (klass != NULL) { if (log_is_enabled(Trace, cds)) { ResourceMark rm; log_trace(cds)("Shared spaces preloaded: %s", klass->external_name()); } 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->is_shared_boot_class())) { // The verification decision is based on BytecodeVerificationRemote // for non-system classes. Since we are using the NULL classloader // to load non-system classes 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; } } // 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_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 mapped shared space. bool MetaspaceShared::is_in_shared_space(const void* p) { return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_space(p); } // 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; } void MetaspaceShared::print_shared_spaces() { if (UseSharedSpaces) { FileMapInfo::current_info()->print_shared_spaces(); } } // 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* _rw_base = NULL; char* _mc_base = NULL; char* _md_base = NULL; char* _od_base = NULL; // Map each shared region if ((_mc_base = mapinfo->map_region(mc)) != NULL && mapinfo->verify_region_checksum(mc) && (_rw_base = mapinfo->map_region(rw)) != NULL && mapinfo->verify_region_checksum(rw) && (_ro_base = mapinfo->map_region(ro)) != NULL && mapinfo->verify_region_checksum(ro) && (_md_base = mapinfo->map_region(md)) != NULL && mapinfo->verify_region_checksum(md) && (_od_base = mapinfo->map_region(od)) != NULL && mapinfo->verify_region_checksum(od) && (image_alignment == (size_t)os::vm_allocation_granularity()) && mapinfo->validate_classpath_entry_table()) { // Success (no need to do anything) 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 = mapinfo->core_spaces_size(); 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(); int sharedDictionaryLen = *(intptr_t*)buffer; buffer += sizeof(intptr_t); int number_of_entries = *(intptr_t*)buffer; buffer += sizeof(intptr_t); SystemDictionary::set_shared_dictionary((HashtableBucket*)buffer, sharedDictionaryLen, number_of_entries); buffer += sharedDictionaryLen; // The following data are the linked list elements // (HashtableEntry objects) for the shared dictionary table. int len = *(intptr_t*)buffer; // skip over shared dictionary entries buffer += sizeof(intptr_t); buffer += len; // 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(); // Close the mapinfo file mapinfo->close(); if (PrintSharedArchiveAndExit) { if (PrintSharedDictionary) { tty->print_cr("\nShared classes:\n"); SystemDictionary::print_shared(false); } if (_archive_loading_failed) { tty->print_cr("archive is invalid"); vm_exit(1); } else { tty->print_cr("archive is valid"); vm_exit(0); } } } void MetaspaceShared::fixup_shared_string_regions() { FileMapInfo *mapinfo = FileMapInfo::current_info(); mapinfo->fixup_string_regions(); } // 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."); }