8207812: Implement Dynamic CDS Archive
Summary: Improve the usability of AppCDS
Reviewed-by: acorn, jiangli, mseledtsov
Contributed-by: ioi.lam@oracle.com, jianglizhou@google.com, calvin.cheung@oracle.com
/*
* Copyright (c) 2012, 2019, 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/javaClasses.inline.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 "gc/shared/softRefPolicy.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 "memory/universe.hpp"
#include "memory/dynamicArchive.hpp"
#include "oops/compressedOops.inline.hpp"
#include "oops/instanceClassLoaderKlass.hpp"
#include "oops/instanceMirrorKlass.hpp"
#include "oops/instanceRefKlass.hpp"
#include "oops/methodData.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/vmOperations.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;
void* MetaspaceShared::_shared_metaspace_static_top = NULL;
// 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.
char* DumpRegion::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;
if (DynamicDumpSharedSpaces) {
delta = DynamicArchive::object_delta_uintx(newtop);
} else {
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;
}
char* DumpRegion::allocate(size_t num_bytes, size_t alignment) {
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 DumpRegion::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 DumpRegion::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 DumpRegion::pack(DumpRegion* next) {
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();
}
}
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;
void MetaspaceShared::init_shared_dump_space(DumpRegion* first_space, address first_space_bottom) {
// 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");
}
first_space->init(&_shared_rs, (char*)first_space_bottom);
}
DumpRegion* MetaspaceShared::misc_code_dump_space() {
return &_mc_region;
}
DumpRegion* MetaspaceShared::read_write_dump_space() {
return &_rw_region;
}
DumpRegion* MetaspaceShared::read_only_dump_space() {
return &_ro_region;
}
DumpRegion* MetaspaceShared::optional_data_dump_space() {
return &_od_region;
}
void MetaspaceShared::pack_dump_space(DumpRegion* current, DumpRegion* next,
ReservedSpace* rs) {
current->pack(next);
}
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_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)
FileMapInfo* mapinfo = new FileMapInfo(true);
// 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(true) && map_shared_spaces(mapinfo)) {
size_t cds_total = core_spaces_size();
address cds_address = (address)mapinfo->region_addr(0);
char* cds_end = (char *)align_up(cds_address + cds_total,
Metaspace::reserve_alignment());
// Mapping the dynamic archive before allocating the class space
cds_end = initialize_dynamic_runtime_shared_spaces((char*)cds_address, cds_end);
#ifdef _LP64
if (Metaspace::using_class_space()) {
// 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();
}
CompressedKlassPointers::set_range(CompressedClassSpaceSize);
#endif // _LP64
} else {
assert(!mapinfo->is_open() && !UseSharedSpaces,
"archive file not closed or shared spaces not disabled.");
}
}
char* MetaspaceShared::initialize_dynamic_runtime_shared_spaces(
char* static_start, char* static_end) {
assert(UseSharedSpaces, "must be runtime");
char* cds_end = static_end;
if (!DynamicDumpSharedSpaces) {
address dynamic_top = DynamicArchive::map();
if (dynamic_top != NULL) {
assert(dynamic_top > (address)static_start, "Unexpected layout");
MetaspaceObj::expand_shared_metaspace_range(dynamic_top);
cds_end = (char *)align_up(dynamic_top, Metaspace::reserve_alignment());
}
}
return cds_end;
}
ReservedSpace* MetaspaceShared::reserve_shared_rs(size_t size, size_t alignment,
bool large, char* requested_address) {
if (requested_address != NULL) {
_shared_rs = ReservedSpace(size, alignment, large, requested_address);
} else {
_shared_rs = ReservedSpace(size, alignment, large);
}
return &_shared_rs;
}
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);
reserve_shared_rs(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);
reserve_shared_rs(cds_total, reserve_alignment, large_pages, NULL);
}
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.
CompressedKlassPointers::set_base((address)_shared_rs.base());
// Set narrow_klass_shift to be LogKlassAlignmentInBytes. This is consistent
// with AOT.
CompressedKlassPointers::set_shift(LogKlassAlignmentInBytes);
// Set the range of klass addresses to 4GB.
CompressedKlassPointers::set_range(cds_total);
Metaspace::initialize_class_space(tmp_class_space);
log_info(cds)("narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
p2i(CompressedKlassPointers::base()), CompressedKlassPointers::shift());
log_info(cds)("Allocated temporary class space: " SIZE_FORMAT " bytes at " PTR_FORMAT,
CompressedClassSpaceSize, p2i(tmp_class_space.base()));
#endif
init_shared_dump_space(&_mc_region);
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);
if (!DynamicDumpSharedSpaces) {
FileMapHeader* header;
if (FileMapInfo::dynamic_info() == NULL) {
header = FileMapInfo::current_info()->header();
} else {
header = FileMapInfo::dynamic_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);
}
}
}
}
static GrowableArray<Handle>* _extra_interned_strings = NULL;
void MetaspaceShared::read_extra_data(const char* filename, TRAPS) {
_extra_interned_strings = new (ResourceObj::C_HEAP, mtInternal)GrowableArray<Handle>(10000, true);
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);
if (utf8_length == 0x7fffffff) {
// buf_len will overflown 32-bit value.
vm_exit_during_initialization(err_msg("string length too large: %d", utf8_length));
}
int buf_len = utf8_length+1;
char* utf8_buffer = NEW_RESOURCE_ARRAY(char, buf_len);
reader.get_utf8(utf8_buffer, utf8_length);
utf8_buffer[utf8_length] = '\0';
if (prefix_type == HashtableTextDump::SymbolPrefix) {
SymbolTable::new_permanent_symbol(utf8_buffer);
} else{
assert(prefix_type == HashtableTextDump::StringPrefix, "Sanity");
oop s = StringTable::intern(utf8_buffer, THREAD);
if (HAS_PENDING_EXCEPTION) {
log_warning(cds, heap)("[line %d] extra interned string allocation failed; size too large: %d",
reader.last_line_no(), utf8_length);
CLEAR_PENDING_EXCEPTION;
} else {
#if INCLUDE_G1GC
if (UseG1GC) {
typeArrayOop body = java_lang_String::value(s);
const HeapRegion* hr = G1CollectedHeap::heap()->heap_region_containing(body);
if (hr->is_humongous()) {
// Don't keep it alive, so it will be GC'ed before we dump the strings, in order
// to maximize free heap space and minimize fragmentation.
log_warning(cds, heap)("[line %d] extra interned string ignored; size too large: %d",
reader.last_line_no(), utf8_length);
continue;
}
}
#endif
// Interned strings are GC'ed if there are no references to it, so let's
// add a reference to keep this string alive.
assert(s != NULL, "must succeed");
Handle h(THREAD, s);
_extra_interned_strings->append(h);
}
}
}
}
void MetaspaceShared::commit_shared_space_to(char* newtop) {
assert(DumpSharedSpaces || DynamicDumpSharedSpaces, "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);
commit = MIN2(commit, uncommitted);
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);
serialize_cloned_cpp_vtptrs(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;
}
uintx MetaspaceShared::object_delta_uintx(void* obj) {
assert(DumpSharedSpaces || DynamicDumpSharedSpaces,
"supported only for dumping");
if (DumpSharedSpaces) {
assert(shared_rs()->contains(obj), "must be");
} else {
assert(is_in_shared_metaspace(obj) || DynamicArchive::is_in_target_space(obj), "must be");
}
address base_address = address(SharedBaseAddress);
uintx deltax = address(obj) - base_address;
return deltax;
}
// 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<Klass*>* _global_klass_objects;
GrowableArray<Klass*>* 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);
MetaspaceShared::rewrite_nofast_bytecodes_and_calculate_fingerprints(ik);
}
}
}
void MetaspaceShared::rewrite_nofast_bytecodes_and_calculate_fingerprints(InstanceKlass* ik) {
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();
}
}
// Objects of the Metadata types (such as Klass and ConstantPool) have C++ vtables.
// (In GCC this is the field <Type>::_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 T> 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 <class T> CppVtableInfo* CppVtableCloner<T>::_info = NULL;
template <class T>
intptr_t* CppVtableCloner<T>::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 _info->cloned_vtable();
}
template <class T>
intptr_t* CppVtableCloner<T>::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 T> class CppVtableTesterB: public T {
public:
virtual int last_virtual_method() {return 1;}
};
template <class T> 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 <class T>
int CppVtableCloner<T>::get_vtable_length(const char* name) {
CppVtableTesterA<T> a;
CppVtableTesterB<T> 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) \
_cloned_cpp_vtptrs[c##_Kind] = CppVtableCloner<c>::allocate(#c);
#define CLONE_CPP_VTABLE(c) \
p = CppVtableCloner<c>::clone_vtable(#c, (CppVtableInfo*)p);
#define ZERO_CPP_VTABLE(c) \
CppVtableCloner<c>::zero_vtable_clone();
//------------------------------ for DynamicDumpSharedSpaces - start
#define DECLARE_CLONED_VTABLE_KIND(c) c ## _Kind,
enum {
CPP_VTABLE_PATCH_TYPES_DO(DECLARE_CLONED_VTABLE_KIND)
_num_cloned_vtable_kinds
};
static intptr_t** _cloned_cpp_vtptrs = NULL;
void MetaspaceShared::serialize_cloned_cpp_vtptrs(SerializeClosure* soc) {
soc->do_ptr((void**)&_cloned_cpp_vtptrs);
}
intptr_t* MetaspaceShared::fix_cpp_vtable_for_dynamic_archive(MetaspaceObj::Type msotype, address obj) {
assert(DynamicDumpSharedSpaces, "must");
int kind = -1;
switch (msotype) {
case MetaspaceObj::SymbolType:
case MetaspaceObj::TypeArrayU1Type:
case MetaspaceObj::TypeArrayU2Type:
case MetaspaceObj::TypeArrayU4Type:
case MetaspaceObj::TypeArrayU8Type:
case MetaspaceObj::TypeArrayOtherType:
case MetaspaceObj::ConstMethodType:
case MetaspaceObj::ConstantPoolCacheType:
case MetaspaceObj::AnnotationsType:
case MetaspaceObj::MethodCountersType:
// These have no vtables.
break;
case MetaspaceObj::ClassType:
{
Klass* k = (Klass*)obj;
assert(k->is_klass(), "must be");
if (k->is_instance_klass()) {
kind = InstanceKlass_Kind;
} else {
assert(k->is_objArray_klass(),
"We shouldn't archive any other klasses in DynamicDumpSharedSpaces");
kind = ObjArrayKlass_Kind;
}
}
break;
case MetaspaceObj::MethodType:
{
Method* m = (Method*)obj;
assert(m->is_method(), "must be");
kind = Method_Kind;
}
break;
case MetaspaceObj::MethodDataType:
// We don't archive MethodData <-- should have been removed in removed_unsharable_info
ShouldNotReachHere();
break;
case MetaspaceObj::ConstantPoolType:
{
ConstantPool *cp = (ConstantPool*)obj;
assert(cp->is_constantPool(), "must be");
kind = ConstantPool_Kind;
}
break;
default:
ShouldNotReachHere();
}
if (kind >= 0) {
assert(kind < _num_cloned_vtable_kinds, "must be");
return _cloned_cpp_vtptrs[kind];
} else {
return NULL;
}
}
//------------------------------ for DynamicDumpSharedSpaces - end
// 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]
// [ <n1> slots for the first vtable]
// [number of slots in the first second = n2]
// [ <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<InstanceClassLoaderKlass>::patch(ik);
} else if (ik->is_reference_instance_klass()) {
CppVtableCloner<InstanceRefKlass>::patch(ik);
} else if (ik->is_mirror_instance_klass()) {
CppVtableCloner<InstanceMirrorKlass>::patch(ik);
} else {
CppVtableCloner<InstanceKlass>::patch(ik);
}
ConstantPool* cp = ik->constants();
CppVtableCloner<ConstantPool>::patch(cp);
for (int j = 0; j < ik->methods()->length(); j++) {
Method* m = ik->methods()->at(j);
CppVtableCloner<Method>::patch(m);
assert(CppVtableCloner<Method>::is_valid_shared_object(m), "must be");
}
} else if (obj->is_objArray_klass()) {
CppVtableCloner<ObjArrayKlass>::patch(obj);
} else {
assert(obj->is_typeArray_klass(), "sanity");
CppVtableCloner<TypeArrayKlass>::patch(obj);
}
}
}
bool MetaspaceShared::is_valid_shared_method(const Method* m) {
assert(is_in_shared_metaspace(m), "must be");
return CppVtableCloner<Method>::is_valid_shared_object(m);
}
void WriteClosure::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 WriteClosure::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);
}
}
// 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<MemRegion> *_closed_archive_heap_regions;
GrowableArray<MemRegion> *_open_archive_heap_regions;
GrowableArray<ArchiveHeapOopmapInfo> *_closed_archive_heap_oopmaps;
GrowableArray<ArchiveHeapOopmapInfo> *_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<MemRegion>* regions,
GrowableArray<ArchiveHeapOopmapInfo>* oopmaps);
void dump_symbols();
char* dump_read_only_tables();
void print_region_stats();
void print_heap_region_stats(GrowableArray<MemRegion> *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<Symbol*> _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<Symbol*>* 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 const int INITIAL_TABLE_SIZE = 8087;
static const int MAX_TABLE_SIZE = 1000000;
static DumpAllocStats* _alloc_stats;
static SortedSymbolClosure* _ssc;
typedef KVHashtable<address, address, mtInternal> RelocationTable;
static RelocationTable* _new_loc_table;
public:
static void initialize() {
_alloc_stats = new(ResourceObj::C_HEAP, mtInternal)DumpAllocStats;
_new_loc_table = new RelocationTable(INITIAL_TABLE_SIZE);
}
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(MAX_TABLE_SIZE)) {
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 bool do_unique_ref(Ref* ref, bool read_only) {
if (read_only == _read_only) {
allocate(ref, read_only);
}
return true; // recurse into ref.obj()
}
};
// Relocate embedded pointers within a MetaspaceObj's shallow copy
class ShallowCopyEmbeddedRefRelocator: public UniqueMetaspaceClosure {
public:
virtual bool 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);
return true; // recurse into ref.obj()
}
};
// 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<Symbol*>* symbols = _ssc->get_sorted_symbols();
for (int i=0; i<symbols->length(); 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);
it->finish();
}
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();
size_t vtptrs_bytes = _num_cloned_vtable_kinds * sizeof(intptr_t*);
_cloned_cpp_vtptrs = (intptr_t**)_ro_region.allocate(vtptrs_bytes, sizeof(intptr_t*));
// 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();
DEBUG_ONLY(SystemDictionaryShared::NoClassLoadingMark nclm);
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<Klass*>(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();
// The 4 core spaces are allocated consecutively mc->rw->ro->md, so there total size
// is just the spaces between the two ends.
size_t core_spaces_size = _md_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(true);
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);
_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();
}
if (AllowArchivingWithJavaAgent) {
warning("This archive was created with AllowArchivingWithJavaAgent. It should be used "
"for testing purposes only and should not be used in a production environment");
}
// 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() +
_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() +
_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);
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<MemRegion> *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.
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");
if (HeapShared::is_heap_object_archiving_allowed()) {
// Avoid fragmentation while archiving heap objects.
Universe::heap()->soft_ref_policy()->set_should_clear_all_soft_refs(true);
Universe::heap()->collect(GCCause::_archive_time_gc);
Universe::heap()->soft_ref_policy()->set_should_clear_all_soft_refs(false);
}
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<MemRegion>(2);
_open_archive_heap_regions = new GrowableArray<MemRegion>(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<ArchiveHeapOopmapInfo>(2);
dump_archive_heap_oopmaps(_closed_archive_heap_regions, _closed_archive_heap_oopmaps);
_open_archive_heap_oopmaps = new GrowableArray<ArchiveHeapOopmapInfo>(2);
dump_archive_heap_oopmaps(_open_archive_heap_regions, _open_archive_heap_oopmaps);
}
}
void VM_PopulateDumpSharedSpace::dump_archive_heap_oopmaps(GrowableArray<MemRegion>* regions,
GrowableArray<ArchiveHeapOopmapInfo>* oopmaps) {
for (int i=0; i<regions->length(); 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
void ReadClosure::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 ReadClosure::do_u4(u4* p) {
intptr_t obj = nextPtr();
*p = (u4)(uintx(obj));
}
void ReadClosure::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 ReadClosure::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 ReadClosure::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);
}
}
void MetaspaceShared::set_shared_metaspace_range(void* base, void* top) {
_shared_metaspace_static_top = top;
MetaspaceObj::set_shared_metaspace_range(base, top);
}
// 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;
}
bool MetaspaceShared::is_shared_dynamic(void* p) {
if ((p < MetaspaceObj::shared_metaspace_top()) &&
(p >= _shared_metaspace_static_top)) {
return true;
} else {
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");
// Map each shared region
int regions[] = {mc, rw, ro, md};
size_t len = sizeof(regions)/sizeof(int);
char* saved_base[] = {NULL, NULL, NULL, NULL};
char* top = mapinfo->map_regions(regions, saved_base, len );
if (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().
_core_spaces_size = mapinfo->core_spaces_size();
set_shared_metaspace_range((void*)saved_base[0], (void*)top);
return true;
} else {
mapinfo->unmap_regions(regions, saved_base, len);
#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();
// Skip over _cloned_cpp_vtptrs;
buffer += _num_cloned_vtable_kinds * sizeof(intptr_t*);
// 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;
}
if (FileMapInfo::dynamic_info() != NULL) {
mapinfo = FileMapInfo::dynamic_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);
vm_exit_during_initialization(err_msg("Unable to allocate from '%s' region", name),
"Please reduce the number of shared classes.");
}