8196626: [Graal] runtime/appcds/UseAppCDS.java crashes with "VM thread using lock Heap_lock (not allowed to block on)"
Summary: print a message and abort CDS dumping when the allocation of metaspace has failed
Reviewed-by: iklam, mseledtsov
/*
* Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "jvm.h"
#include "classfile/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/stringTable.hpp"
#include "classfile/systemDictionary.hpp"
#include "classfile/systemDictionaryShared.hpp"
#include "code/codeCache.hpp"
#if INCLUDE_ALL_GCS
#include "gc/g1/g1Allocator.inline.hpp"
#include "gc/g1/g1CollectedHeap.hpp"
#endif
#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/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;
bool MetaspaceShared::_open_archive_heap_region_mapped = 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(closed archive heap space) #0
// s1 - shared strings(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 MetaspaceShared::dump_java_heap_objects.
// Their layout is independent of the other 5 regions.
class DumpRegion {
private:
const char* _name;
char* _base;
char* _top;
char* _end;
bool _is_packed;
char* expand_top_to(char* newtop) {
assert(is_allocatable(), "must be initialized and not packed");
assert(newtop >= _top, "must not grow backwards");
if (newtop > _end) {
MetaspaceShared::report_out_of_space(_name, newtop - _top);
ShouldNotReachHere();
}
MetaspaceShared::commit_shared_space_to(newtop);
_top = newtop;
return _top;
}
public:
DumpRegion(const char* name) : _name(name), _base(NULL), _top(NULL), _end(NULL), _is_packed(false) {}
char* allocate(size_t num_bytes, size_t alignment=BytesPerWord) {
char* p = (char*)align_up(_top, alignment);
char* newtop = p + align_up(num_bytes, alignment);
expand_top_to(newtop);
memset(p, 0, newtop - p);
return p;
}
void append_intptr_t(intptr_t n) {
assert(is_aligned(_top, sizeof(intptr_t)), "bad alignment");
intptr_t *p = (intptr_t*)_top;
char* newtop = _top + sizeof(intptr_t);
expand_top_to(newtop);
*p = n;
}
char* base() const { return _base; }
char* top() const { return _top; }
char* end() const { return _end; }
size_t reserved() const { return _end - _base; }
size_t used() const { return _top - _base; }
bool is_packed() const { return _is_packed; }
bool is_allocatable() const {
return !is_packed() && _base != NULL;
}
void print(size_t total_bytes) const {
tty->print_cr("%-3s space: " SIZE_FORMAT_W(9) " [ %4.1f%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used] at " INTPTR_FORMAT,
_name, used(), percent_of(used(), total_bytes), reserved(), percent_of(used(), reserved()), p2i(_base));
}
void print_out_of_space_msg(const char* failing_region, size_t needed_bytes) {
tty->print("[%-8s] " PTR_FORMAT " - " PTR_FORMAT " capacity =%9d, allocated =%9d",
_name, p2i(_base), p2i(_top), int(_end - _base), int(_top - _base));
if (strcmp(_name, failing_region) == 0) {
tty->print_cr(" required = %d", int(needed_bytes));
} else {
tty->cr();
}
}
void init(const ReservedSpace* rs) {
_base = _top = rs->base();
_end = rs->end();
}
void init(char* b, char* t, char* e) {
_base = b;
_top = t;
_end = e;
}
void pack(DumpRegion* next = NULL) {
assert(!is_packed(), "sanity");
_end = (char*)align_up(_top, Metaspace::reserve_alignment());
_is_packed = true;
if (next != NULL) {
next->_base = next->_top = this->_end;
next->_end = MetaspaceShared::shared_rs()->end();
}
}
bool contains(char* p) {
return base() <= p && p < top();
}
};
DumpRegion _mc_region("mc"), _ro_region("ro"), _rw_region("rw"), _md_region("md"), _od_region("od");
size_t _total_string_region_size = 0, _total_open_archive_region_size = 0;
char* MetaspaceShared::misc_code_space_alloc(size_t num_bytes) {
return _mc_region.allocate(num_bytes);
}
char* MetaspaceShared::read_only_space_alloc(size_t num_bytes) {
return _ro_region.allocate(num_bytes);
}
void MetaspaceShared::initialize_runtime_shared_and_meta_spaces() {
assert(UseSharedSpaces, "Must be called when UseSharedSpaces is enabled");
// If using shared space, open the file that contains the shared space
// and map in the memory before initializing the rest of metaspace (so
// the addresses don't conflict)
address cds_address = NULL;
FileMapInfo* mapinfo = new FileMapInfo();
// Open the shared archive file, read and validate the header. If
// initialization fails, shared spaces [UseSharedSpaces] are
// disabled and the file is closed.
// Map in spaces now also
if (mapinfo->initialize() && map_shared_spaces(mapinfo)) {
size_t cds_total = core_spaces_size();
cds_address = (address)mapinfo->header()->region_addr(0);
#ifdef _LP64
if (Metaspace::using_class_space()) {
char* cds_end = (char*)(cds_address + cds_total);
cds_end = (char *)align_up(cds_end, Metaspace::reserve_alignment());
// If UseCompressedClassPointers is set then allocate the metaspace area
// above the heap and above the CDS area (if it exists).
Metaspace::allocate_metaspace_compressed_klass_ptrs(cds_end, cds_address);
// map_heap_regions() compares the current narrow oop and klass encodings
// with the archived ones, so it must be done after all encodings are determined.
mapinfo->map_heap_regions();
}
#endif // _LP64
} else {
assert(!mapinfo->is_open() && !UseSharedSpaces,
"archive file not closed or shared spaces not disabled.");
}
}
void MetaspaceShared::initialize_dumptime_shared_and_meta_spaces() {
assert(DumpSharedSpaces, "should be called for dump time only");
const size_t reserve_alignment = Metaspace::reserve_alignment();
bool large_pages = false; // No large pages when dumping the CDS archive.
char* shared_base = (char*)align_up((char*)SharedBaseAddress, reserve_alignment);
#ifdef _LP64
// On 64-bit VM, the heap and class space layout will be the same as if
// you're running in -Xshare:on mode:
//
// +-- SharedBaseAddress (default = 0x800000000)
// v
// +-..---------+---------+ ... +----+----+----+----+----+---------------+
// | Heap | Archive | | MC | RW | RO | MD | OD | class space |
// +-..---------+---------+ ... +----+----+----+----+----+---------------+
// |<-- MaxHeapSize -->| |<-- UnscaledClassSpaceMax = 4GB ------->|
//
const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1);
const size_t cds_total = align_down(UnscaledClassSpaceMax, reserve_alignment);
#else
// We don't support archives larger than 256MB on 32-bit due to limited virtual address space.
size_t cds_total = align_down(256*M, reserve_alignment);
#endif
// First try to reserve the space at the specified SharedBaseAddress.
_shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages, shared_base);
if (_shared_rs.is_reserved()) {
assert(shared_base == 0 || _shared_rs.base() == shared_base, "should match");
} else {
// Get a mmap region anywhere if the SharedBaseAddress fails.
_shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages);
}
if (!_shared_rs.is_reserved()) {
vm_exit_during_initialization("Unable to reserve memory for shared space",
err_msg(SIZE_FORMAT " bytes.", cds_total));
}
#ifdef _LP64
// During dump time, we allocate 4GB (UnscaledClassSpaceMax) of space and split it up:
// + The upper 1 GB is used as the "temporary compressed class space" -- preload_classes()
// will store Klasses into this space.
// + The lower 3 GB is used for the archive -- when preload_classes() is done,
// ArchiveCompactor will copy the class metadata into this space, first the RW parts,
// then the RO parts.
assert(UseCompressedOops && UseCompressedClassPointers,
"UseCompressedOops and UseCompressedClassPointers must be set");
size_t max_archive_size = align_down(cds_total * 3 / 4, reserve_alignment);
ReservedSpace tmp_class_space = _shared_rs.last_part(max_archive_size);
CompressedClassSpaceSize = align_down(tmp_class_space.size(), reserve_alignment);
_shared_rs = _shared_rs.first_part(max_archive_size);
// Set up compress class pointers.
Universe::set_narrow_klass_base((address)_shared_rs.base());
// Set narrow_klass_shift to be LogKlassAlignmentInBytes. This is consistent
// with AOT.
Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes);
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);
serialize_well_known_classes(soc);
soc->do_tag(--tag);
soc->do_tag(666);
}
void MetaspaceShared::serialize_well_known_classes(SerializeClosure* soc) {
java_lang_Class::serialize(soc);
java_lang_String::serialize(soc);
java_lang_System::serialize(soc);
java_lang_ClassLoader::serialize(soc);
java_lang_Throwable::serialize(soc);
java_lang_Thread::serialize(soc);
java_lang_ThreadGroup::serialize(soc);
java_lang_AssertionStatusDirectives::serialize(soc);
java_lang_ref_SoftReference::serialize(soc);
java_lang_invoke_MethodHandle::serialize(soc);
java_lang_invoke_DirectMethodHandle::serialize(soc);
java_lang_invoke_MemberName::serialize(soc);
java_lang_invoke_ResolvedMethodName::serialize(soc);
java_lang_invoke_LambdaForm::serialize(soc);
java_lang_invoke_MethodType::serialize(soc);
java_lang_invoke_CallSite::serialize(soc);
java_lang_invoke_MethodHandleNatives_CallSiteContext::serialize(soc);
java_security_AccessControlContext::serialize(soc);
java_lang_reflect_AccessibleObject::serialize(soc);
java_lang_reflect_Method::serialize(soc);
java_lang_reflect_Constructor::serialize(soc);
java_lang_reflect_Field::serialize(soc);
java_nio_Buffer::serialize(soc);
reflect_ConstantPool::serialize(soc);
reflect_UnsafeStaticFieldAccessorImpl::serialize(soc);
java_lang_reflect_Parameter::serialize(soc);
java_lang_Module::serialize(soc);
java_lang_StackTraceElement::serialize(soc);
java_lang_StackFrameInfo::serialize(soc);
java_lang_LiveStackFrameInfo::serialize(soc);
}
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<Klass*>* _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 (!UseAppCDS && !k->class_loader_data()->is_the_null_class_loader_data()) {
// AppCDS is not enabled. Let's omit non-boot classes.
return;
}
if (!(k->is_instance_klass() && InstanceKlass::cast(k)->is_in_error_state())) {
if (k->is_instance_klass() && InstanceKlass::cast(k)->signers() != NULL) {
// Mark any class with signers and don't add to the _global_klass_objects
k->set_has_signer_and_not_archived();
} 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(!MetaspaceShared::is_heap_object_archiving_allowed(), "Sanity");
Universe::set_int_mirror(NULL);
Universe::set_float_mirror(NULL);
Universe::set_double_mirror(NULL);
Universe::set_byte_mirror(NULL);
Universe::set_bool_mirror(NULL);
Universe::set_char_mirror(NULL);
Universe::set_long_mirror(NULL);
Universe::set_short_mirror(NULL);
Universe::set_void_mirror(NULL);
}
static void rewrite_nofast_bytecode(Method* method) {
BytecodeStream bcs(method);
while (!bcs.is_last_bytecode()) {
Bytecodes::Code opcode = bcs.next();
switch (opcode) {
case Bytecodes::_getfield: *bcs.bcp() = Bytecodes::_nofast_getfield; break;
case Bytecodes::_putfield: *bcs.bcp() = Bytecodes::_nofast_putfield; break;
case Bytecodes::_aload_0: *bcs.bcp() = Bytecodes::_nofast_aload_0; break;
case Bytecodes::_iload: {
if (!bcs.is_wide()) {
*bcs.bcp() = Bytecodes::_nofast_iload;
}
break;
}
default: break;
}
}
}
// Walk all methods in the class list to ensure that they won't be modified at
// run time. This includes:
// [1] Rewrite all bytecodes as needed, so that the ConstMethod* will not be modified
// at run time by RewriteBytecodes/RewriteFrequentPairs
// [2] Assign a fingerprint, so one doesn't need to be assigned at run-time.
static void rewrite_nofast_bytecodes_and_calculate_fingerprints() {
for (int i = 0; i < _global_klass_objects->length(); i++) {
Klass* k = _global_klass_objects->at(i);
if (k->is_instance_klass()) {
InstanceKlass* ik = InstanceKlass::cast(k);
for (int i = 0; i < ik->methods()->length(); i++) {
Method* m = ik->methods()->at(i);
rewrite_nofast_bytecode(m);
Fingerprinter fp(m);
// The side effect of this call sets method's fingerprint field.
fp.fingerprint();
}
}
}
}
static void relocate_cached_class_file() {
for (int i = 0; i < _global_klass_objects->length(); i++) {
Klass* k = _global_klass_objects->at(i);
if (k->is_instance_klass()) {
InstanceKlass* ik = InstanceKlass::cast(k);
JvmtiCachedClassFileData* p = ik->get_archived_class_data();
if (p != NULL) {
int size = offset_of(JvmtiCachedClassFileData, data) + p->length;
JvmtiCachedClassFileData* q = (JvmtiCachedClassFileData*)_od_region.allocate(size);
q->length = p->length;
memcpy(q->data, p->data, p->length);
ik->set_archived_class_data(q);
}
}
}
}
NOT_PRODUCT(
static void assert_not_anonymous_class(InstanceKlass* k) {
assert(!(k->is_anonymous()), "cannot archive anonymous classes");
}
// Anonymous classes are not stored inside any dictionaries. They are created by
// SystemDictionary::parse_stream() with a non-null host_klass.
static void assert_no_anonymoys_classes_in_dictionaries() {
ClassLoaderDataGraph::dictionary_classes_do(assert_not_anonymous_class);
})
// 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 p;
}
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) \
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();
// 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);
}
// Closure for serializing initialization data out to a data area to be
// written to the shared file.
class WriteClosure : public SerializeClosure {
private:
DumpRegion* _dump_region;
public:
WriteClosure(DumpRegion* r) {
_dump_region = r;
}
void do_ptr(void** p) {
_dump_region->append_intptr_t((intptr_t)*p);
}
void do_u4(u4* p) {
void* ptr = (void*)(uintx(*p));
do_ptr(&ptr);
}
void do_tag(int tag) {
_dump_region->append_intptr_t((intptr_t)tag);
}
void do_oop(oop* o) {
if (*o == NULL) {
_dump_region->append_intptr_t(0);
} else {
assert(MetaspaceShared::is_heap_object_archiving_allowed(),
"Archiving heap object is not allowed");
_dump_region->append_intptr_t(
(intptr_t)oopDesc::encode_heap_oop_not_null(*o));
}
}
void do_region(u_char* start, size_t size) {
assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
assert(size % sizeof(intptr_t) == 0, "bad size");
do_tag((int)size);
while (size > 0) {
_dump_region->append_intptr_t(*(intptr_t*)start);
start += sizeof(intptr_t);
size -= sizeof(intptr_t);
}
}
bool reading() const { return false; }
};
// This is for dumping detailed statistics for the allocations
// in the shared spaces.
class DumpAllocStats : public ResourceObj {
public:
// Here's poor man's enum inheritance
#define SHAREDSPACE_OBJ_TYPES_DO(f) \
METASPACE_OBJ_TYPES_DO(f) \
f(SymbolHashentry) \
f(SymbolBucket) \
f(StringHashentry) \
f(StringBucket) \
f(Other)
enum Type {
// Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc
SHAREDSPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_DECLARE)
_number_of_types
};
static const char * type_name(Type type) {
switch(type) {
SHAREDSPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_NAME_CASE)
default:
ShouldNotReachHere();
return NULL;
}
}
public:
enum { RO = 0, RW = 1 };
int _counts[2][_number_of_types];
int _bytes [2][_number_of_types];
DumpAllocStats() {
memset(_counts, 0, sizeof(_counts));
memset(_bytes, 0, sizeof(_bytes));
};
void record(MetaspaceObj::Type type, int byte_size, bool read_only) {
assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity");
int which = (read_only) ? RO : RW;
_counts[which][type] ++;
_bytes [which][type] += byte_size;
}
void record_other_type(int byte_size, bool read_only) {
int which = (read_only) ? RO : RW;
_bytes [which][OtherType] += byte_size;
}
void print_stats(int ro_all, int rw_all, int mc_all, int md_all);
};
void DumpAllocStats::print_stats(int ro_all, int rw_all, int mc_all, int md_all) {
// Calculate size of data that was not allocated by Metaspace::allocate()
MetaspaceSharedStats *stats = MetaspaceShared::stats();
// symbols
_counts[RO][SymbolHashentryType] = stats->symbol.hashentry_count;
_bytes [RO][SymbolHashentryType] = stats->symbol.hashentry_bytes;
_counts[RO][SymbolBucketType] = stats->symbol.bucket_count;
_bytes [RO][SymbolBucketType] = stats->symbol.bucket_bytes;
// strings
_counts[RO][StringHashentryType] = stats->string.hashentry_count;
_bytes [RO][StringHashentryType] = stats->string.hashentry_bytes;
_counts[RO][StringBucketType] = stats->string.bucket_count;
_bytes [RO][StringBucketType] = stats->string.bucket_bytes;
// TODO: count things like dictionary, vtable, etc
_bytes[RW][OtherType] += mc_all + md_all;
rw_all += mc_all + md_all; // mc/md are mapped Read/Write
// prevent divide-by-zero
if (ro_all < 1) {
ro_all = 1;
}
if (rw_all < 1) {
rw_all = 1;
}
int all_ro_count = 0;
int all_ro_bytes = 0;
int all_rw_count = 0;
int all_rw_bytes = 0;
// To make fmt_stats be a syntactic constant (for format warnings), use #define.
#define fmt_stats "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f"
const char *sep = "--------------------+---------------------------+---------------------------+--------------------------";
const char *hdr = " ro_cnt ro_bytes % | rw_cnt rw_bytes % | all_cnt all_bytes %";
LogMessage(cds) msg;
msg.info("Detailed metadata info (excluding od/st regions; rw stats include md/mc regions):");
msg.info("%s", hdr);
msg.info("%s", sep);
for (int type = 0; type < int(_number_of_types); type ++) {
const char *name = type_name((Type)type);
int ro_count = _counts[RO][type];
int ro_bytes = _bytes [RO][type];
int rw_count = _counts[RW][type];
int rw_bytes = _bytes [RW][type];
int count = ro_count + rw_count;
int bytes = ro_bytes + rw_bytes;
double ro_perc = percent_of(ro_bytes, ro_all);
double rw_perc = percent_of(rw_bytes, rw_all);
double perc = percent_of(bytes, ro_all + rw_all);
msg.info(fmt_stats, name,
ro_count, ro_bytes, ro_perc,
rw_count, rw_bytes, rw_perc,
count, bytes, perc);
all_ro_count += ro_count;
all_ro_bytes += ro_bytes;
all_rw_count += rw_count;
all_rw_bytes += rw_bytes;
}
int all_count = all_ro_count + all_rw_count;
int all_bytes = all_ro_bytes + all_rw_bytes;
double all_ro_perc = percent_of(all_ro_bytes, ro_all);
double all_rw_perc = percent_of(all_rw_bytes, rw_all);
double all_perc = percent_of(all_bytes, ro_all + rw_all);
msg.info("%s", sep);
msg.info(fmt_stats, "Total",
all_ro_count, all_ro_bytes, all_ro_perc,
all_rw_count, all_rw_bytes, all_rw_perc,
all_count, all_bytes, all_perc);
assert(all_ro_bytes == ro_all, "everything should have been counted");
assert(all_rw_bytes == rw_all, "everything should have been counted");
#undef fmt_stats
}
// Populate the shared space.
class VM_PopulateDumpSharedSpace: public VM_Operation {
private:
GrowableArray<MemRegion> *_closed_archive_heap_regions;
GrowableArray<MemRegion> *_open_archive_heap_regions;
void dump_java_heap_objects() NOT_CDS_JAVA_HEAP_RETURN;
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 DumpAllocStats* _alloc_stats;
static SortedSymbolClosure* _ssc;
static unsigned my_hash(const address& a) {
return primitive_hash<address>(a);
}
static bool my_equals(const address& a0, const address& a1) {
return primitive_equals<address>(a0, a1);
}
typedef ResourceHashtable<
address, address,
ArchiveCompactor::my_hash, // solaris compiler doesn't like: primitive_hash<address>
ArchiveCompactor::my_equals, // solaris compiler doesn't like: primitive_equals<address>
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);
log_trace(cds)("Copy: " PTR_FORMAT " ==> " PTR_FORMAT " %d", p2i(obj), p2i(p), bytes);
assert(isnew, "must be");
_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
// 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 objects
// in the CDS shared string regions) 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);
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) {
assert(DumpSharedSpaces, "dump time only");
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_symbols() {
tty->print_cr("Dumping symbol table ...");
NOT_PRODUCT(SymbolTable::verify());
SymbolTable::write_to_archive();
}
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();
tty->print("Removing java_mirror ... ");
if (!MetaspaceShared::is_heap_object_archiving_allowed()) {
clear_basic_type_mirrors();
}
remove_java_mirror_in_classes();
tty->print_cr("done. ");
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<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. ");
// Move classes from platform/system dictionaries into the boot dictionary
SystemDictionary::combine_shared_dictionaries();
// Remove all references outside the metadata
tty->print("Removing unshareable information ... ");
remove_unshareable_in_classes();
tty->print_cr("done. ");
// We don't support archiving anonymous classes. Verify that they are not stored in
// the any dictionaries.
NOT_PRODUCT(assert_no_anonymoys_classes_in_dictionaries());
SystemDictionaryShared::finalize_verification_constraints();
ArchiveCompactor::initialize();
ArchiveCompactor::copy_and_compact();
dump_symbols();
// Dump supported java heap objects
_closed_archive_heap_regions = NULL;
_open_archive_heap_regions = NULL;
dump_java_heap_objects();
ArchiveCompactor::relocate_well_known_klasses();
char* read_only_tables_start = dump_read_only_tables();
_ro_region.pack(&_md_region);
char* vtbl_list = _md_region.top();
MetaspaceShared::allocate_cpp_vtable_clones();
_md_region.pack(&_od_region);
// Relocate the archived class file data into the od region
relocate_cached_class_file();
_od_region.pack();
// The 5 core spaces are allocated consecutively mc->rw->ro->md->od, so there total size
// is just the spaces between the two ends.
size_t core_spaces_size = _od_region.end() - _mc_region.base();
assert(core_spaces_size == (size_t)align_up(core_spaces_size, Metaspace::reserve_alignment()),
"should already be aligned");
// During patching, some virtual methods may be called, so at this point
// the vtables must contain valid methods (as filled in by CppVtableCloner::allocate).
MetaspaceShared::patch_cpp_vtable_pointers();
// The vtable clones contain addresses of the current process.
// We don't want to write these addresses into the archive.
MetaspaceShared::zero_cpp_vtable_clones_for_writing();
// Create and write the archive file that maps the shared spaces.
FileMapInfo* mapinfo = new FileMapInfo();
mapinfo->populate_header(os::vm_allocation_granularity());
mapinfo->set_read_only_tables_start(read_only_tables_start);
mapinfo->set_misc_data_patching_start(vtbl_list);
mapinfo->set_cds_i2i_entry_code_buffers(MetaspaceShared::cds_i2i_entry_code_buffers());
mapinfo->set_cds_i2i_entry_code_buffers_size(MetaspaceShared::cds_i2i_entry_code_buffers_size());
mapinfo->set_core_spaces_size(core_spaces_size);
for (int pass=1; pass<=2; pass++) {
if (pass == 1) {
// The first pass doesn't actually write the data to disk. All it
// does is to update the fields in the mapinfo->_header.
} else {
// After the first pass, the contents of mapinfo->_header are finalized,
// so we can compute the header's CRC, and write the contents of the header
// and the regions into disk.
mapinfo->open_for_write();
mapinfo->set_header_crc(mapinfo->compute_header_crc());
}
mapinfo->write_header();
// NOTE: md contains the trampoline code for method entries, which are patched at run time,
// so it needs to be read/write.
write_region(mapinfo, MetaspaceShared::mc, &_mc_region, /*read_only=*/false,/*allow_exec=*/true);
write_region(mapinfo, MetaspaceShared::rw, &_rw_region, /*read_only=*/false,/*allow_exec=*/false);
write_region(mapinfo, MetaspaceShared::ro, &_ro_region, /*read_only=*/true, /*allow_exec=*/false);
write_region(mapinfo, MetaspaceShared::md, &_md_region, /*read_only=*/false,/*allow_exec=*/false);
write_region(mapinfo, MetaspaceShared::od, &_od_region, /*read_only=*/true, /*allow_exec=*/false);
_total_string_region_size = mapinfo->write_archive_heap_regions(
_closed_archive_heap_regions,
MetaspaceShared::first_string,
MetaspaceShared::max_strings);
_total_open_archive_region_size = mapinfo->write_archive_heap_regions(
_open_archive_heap_regions,
MetaspaceShared::first_open_archive_heap_region,
MetaspaceShared::max_open_archive_heap_region);
}
mapinfo->close();
// Restore the vtable in case we invoke any virtual methods.
MetaspaceShared::clone_cpp_vtables((intptr_t*)vtbl_list);
print_region_stats();
if (log_is_enabled(Info, cds)) {
ArchiveCompactor::alloc_stats()->print_stats(int(_ro_region.used()), int(_rw_region.used()),
int(_mc_region.used()), int(_md_region.used()));
}
if (PrintSystemDictionaryAtExit) {
SystemDictionary::print();
}
// There may be other pending VM operations that operate on the InstanceKlasses,
// which will fail because InstanceKlasses::remove_unshareable_info()
// has been called. Forget these operations and exit the VM directly.
vm_direct_exit(0);
}
void VM_PopulateDumpSharedSpace::print_region_stats() {
// Print statistics of all the regions
const size_t total_reserved = _ro_region.reserved() + _rw_region.reserved() +
_mc_region.reserved() + _md_region.reserved() +
_od_region.reserved() +
_total_string_region_size +
_total_open_archive_region_size;
const size_t total_bytes = _ro_region.used() + _rw_region.used() +
_mc_region.used() + _md_region.used() +
_od_region.used() +
_total_string_region_size +
_total_open_archive_region_size;
const double total_u_perc = percent_of(total_bytes, total_reserved);
_mc_region.print(total_reserved);
_rw_region.print(total_reserved);
_ro_region.print(total_reserved);
_md_region.print(total_reserved);
_od_region.print(total_reserved);
print_heap_region_stats(_closed_archive_heap_regions, "st", 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::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);
}
}
}
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");
SystemDictionary::clear_invoke_method_table();
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 = ClassLoaderExt::load_one_class(&parser, 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->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;
}
}
#if INCLUDE_CDS_JAVA_HEAP
void VM_PopulateDumpSharedSpace::dump_java_heap_objects() {
if (!MetaspaceShared::is_heap_object_archiving_allowed()) {
if (log_is_enabled(Info, cds)) {
log_info(cds)(
"Archived java heap is not supported as UseG1GC, "
"UseCompressedOops and UseCompressedClassPointers are required."
"Current settings: UseG1GC=%s, UseCompressedOops=%s, UseCompressedClassPointers=%s.",
BOOL_TO_STR(UseG1GC), BOOL_TO_STR(UseCompressedOops),
BOOL_TO_STR(UseCompressedClassPointers));
}
return;
}
{
NoSafepointVerifier nsv;
// Cache for recording where the archived objects are copied to
MetaspaceShared::create_archive_object_cache();
tty->print_cr("Dumping objects to closed archive heap region ...");
NOT_PRODUCT(StringTable::verify());
// The closed space has maximum two regions. See FileMapInfo::write_archive_heap_regions() for details.
_closed_archive_heap_regions = new GrowableArray<MemRegion>(2);
MetaspaceShared::dump_closed_archive_heap_objects(_closed_archive_heap_regions);
tty->print_cr("Dumping objects to open archive heap region ...");
_open_archive_heap_regions = new GrowableArray<MemRegion>(2);
MetaspaceShared::dump_open_archive_heap_objects(_open_archive_heap_regions);
MetaspaceShared::destroy_archive_object_cache();
}
G1HeapVerifier::verify_archive_regions();
}
void MetaspaceShared::dump_closed_archive_heap_objects(
GrowableArray<MemRegion> * closed_archive) {
assert(is_heap_object_archiving_allowed(), "Cannot dump java heap objects");
Thread* THREAD = Thread::current();
G1CollectedHeap::heap()->begin_archive_alloc_range();
// Archive interned string objects
StringTable::write_to_archive(closed_archive);
G1CollectedHeap::heap()->end_archive_alloc_range(closed_archive,
os::vm_allocation_granularity());
}
void MetaspaceShared::dump_open_archive_heap_objects(
GrowableArray<MemRegion> * open_archive) {
assert(UseG1GC, "Only support G1 GC");
assert(UseCompressedOops && UseCompressedClassPointers,
"Only support UseCompressedOops and UseCompressedClassPointers enabled");
Thread* THREAD = Thread::current();
G1CollectedHeap::heap()->begin_archive_alloc_range(true /* open */);
java_lang_Class::archive_basic_type_mirrors(THREAD);
MetaspaceShared::archive_klass_objects(THREAD);
G1CollectedHeap::heap()->end_archive_alloc_range(open_archive,
os::vm_allocation_granularity());
}
MetaspaceShared::ArchivedObjectCache* MetaspaceShared::_archive_object_cache = NULL;
oop MetaspaceShared::find_archived_heap_object(oop obj) {
assert(DumpSharedSpaces, "dump-time only");
ArchivedObjectCache* cache = MetaspaceShared::archive_object_cache();
oop* p = cache->get(obj);
if (p != NULL) {
return *p;
} else {
return NULL;
}
}
oop MetaspaceShared::archive_heap_object(oop obj, Thread* THREAD) {
assert(DumpSharedSpaces, "dump-time only");
oop ao = find_archived_heap_object(obj);
if (ao != NULL) {
// already archived
return ao;
}
int len = obj->size();
if (G1CollectedHeap::heap()->is_archive_alloc_too_large(len)) {
return NULL;
}
int hash = obj->identity_hash();
oop archived_oop = (oop)G1CollectedHeap::heap()->archive_mem_allocate(len);
if (archived_oop != NULL) {
Copy::aligned_disjoint_words((HeapWord*)obj, (HeapWord*)archived_oop, len);
relocate_klass_ptr(archived_oop);
ArchivedObjectCache* cache = MetaspaceShared::archive_object_cache();
cache->put(obj, archived_oop);
}
log_debug(cds)("Archived heap object " PTR_FORMAT " ==> " PTR_FORMAT,
p2i(obj), p2i(archived_oop));
return archived_oop;
}
void MetaspaceShared::archive_klass_objects(Thread* THREAD) {
int i;
for (i = 0; i < _global_klass_objects->length(); i++) {
Klass* k = _global_klass_objects->at(i);
// archive mirror object
java_lang_Class::archive_mirror(k, CHECK);
// archive the resolved_referenes array
if (k->is_instance_klass()) {
InstanceKlass* ik = InstanceKlass::cast(k);
ik->constants()->archive_resolved_references(THREAD);
}
}
}
void MetaspaceShared::fixup_mapped_heap_regions() {
FileMapInfo *mapinfo = FileMapInfo::current_info();
mapinfo->fixup_mapped_heap_regions();
}
#endif // INCLUDE_CDS_JAVA_HEAP
// Closure for serializing initialization data in from a data area
// (ptr_array) read from the shared file.
class ReadClosure : public SerializeClosure {
private:
intptr_t** _ptr_array;
inline intptr_t nextPtr() {
return *(*_ptr_array)++;
}
public:
ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
void do_ptr(void** p) {
assert(*p == NULL, "initializing previous initialized pointer.");
intptr_t obj = nextPtr();
assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
"hit tag while initializing ptrs.");
*p = (void*)obj;
}
void do_u4(u4* p) {
intptr_t obj = nextPtr();
*p = (u4)(uintx(obj));
}
void do_tag(int tag) {
int old_tag;
old_tag = (int)(intptr_t)nextPtr();
// do_int(&old_tag);
assert(tag == old_tag, "old tag doesn't match");
FileMapInfo::assert_mark(tag == old_tag);
}
void do_oop(oop *p) {
narrowOop o = (narrowOop)nextPtr();
if (o == 0 || !MetaspaceShared::open_archive_heap_region_mapped()) {
p = NULL;
} else {
assert(MetaspaceShared::is_heap_object_archiving_allowed(),
"Archived heap object is not allowed");
assert(MetaspaceShared::open_archive_heap_region_mapped(),
"Open archive heap region is not mapped");
RootAccess<IN_ARCHIVE_ROOT>::oop_store(p, oopDesc::decode_heap_oop_not_null(o));
}
}
void do_region(u_char* start, size_t size) {
assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
assert(size % sizeof(intptr_t) == 0, "bad size");
do_tag((int)size);
while (size > 0) {
*(intptr_t*)start = nextPtr();
start += sizeof(intptr_t);
size -= sizeof(intptr_t);
}
}
bool reading() const { return true; }
};
// Return true if given address is in the misc data region
bool MetaspaceShared::is_in_shared_region(const void* p, int idx) {
return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_region(p, idx);
}
bool MetaspaceShared::is_in_trampoline_frame(address addr) {
if (UseSharedSpaces && is_in_shared_region(addr, MetaspaceShared::mc)) {
return true;
}
return false;
}
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* ro_top;
char* rw_base = NULL; char* rw_top;
char* mc_base = NULL; char* mc_top;
char* md_base = NULL; char* md_top;
char* od_base = NULL; char* od_top;
// Map each shared region
if ((mc_base = mapinfo->map_region(mc, &mc_top)) != NULL &&
(rw_base = mapinfo->map_region(rw, &rw_top)) != NULL &&
(ro_base = mapinfo->map_region(ro, &ro_top)) != NULL &&
(md_base = mapinfo->map_region(md, &md_top)) != NULL &&
(od_base = mapinfo->map_region(od, &od_top)) != NULL &&
(image_alignment == (size_t)os::vm_allocation_granularity()) &&
mapinfo->validate_classpath_entry_table()) {
// Success -- set up MetaspaceObj::_shared_metaspace_{base,top} for
// fast checking in MetaspaceShared::is_in_shared_metaspace() and
// MetaspaceObj::is_shared().
//
// We require that mc->rw->ro->md->od to be laid out consecutively, with no
// gaps between them. That way, we can ensure that the OS won't be able to
// allocate any new memory spaces inside _shared_metaspace_{base,top}, which
// would mess up the simple comparision in MetaspaceShared::is_in_shared_metaspace().
assert(mc_base < ro_base && mc_base < rw_base && mc_base < md_base && mc_base < od_base, "must be");
assert(od_top > ro_top && od_top > rw_top && od_top > md_top && od_top > mc_top , "must be");
assert(mc_top == rw_base, "must be");
assert(rw_top == ro_base, "must be");
assert(ro_top == md_base, "must be");
assert(md_top == od_base, "must be");
MetaspaceObj::_shared_metaspace_base = (void*)mc_base;
MetaspaceObj::_shared_metaspace_top = (void*)od_top;
return true;
} else {
// If there was a failure in mapping any of the spaces, unmap the ones
// that succeeded
if (ro_base != NULL) mapinfo->unmap_region(ro);
if (rw_base != NULL) mapinfo->unmap_region(rw);
if (mc_base != NULL) mapinfo->unmap_region(mc);
if (md_base != NULL) mapinfo->unmap_region(md);
if (od_base != NULL) mapinfo->unmap_region(od);
#ifndef _WINDOWS
// Release the entire mapped region
shared_rs.release();
#endif
// If -Xshare:on is specified, print out the error message and exit VM,
// otherwise, set UseSharedSpaces to false and continue.
if (RequireSharedSpaces || PrintSharedArchiveAndExit) {
vm_exit_during_initialization("Unable to use shared archive.", "Failed map_region for using -Xshare:on.");
} else {
FLAG_SET_DEFAULT(UseSharedSpaces, false);
}
return false;
}
}
// Read the miscellaneous data from the shared file, and
// serialize it out to its various destinations.
void MetaspaceShared::initialize_shared_spaces() {
FileMapInfo *mapinfo = FileMapInfo::current_info();
_cds_i2i_entry_code_buffers = mapinfo->cds_i2i_entry_code_buffers();
_cds_i2i_entry_code_buffers_size = mapinfo->cds_i2i_entry_code_buffers_size();
_core_spaces_size = 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<mtClass>*)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(tty);
}
if (_archive_loading_failed) {
tty->print_cr("archive is invalid");
vm_exit(1);
} else {
tty->print_cr("archive is valid");
vm_exit(0);
}
}
}
// JVM/TI RedefineClasses() support:
bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
if (UseSharedSpaces) {
// remap the shared readonly space to shared readwrite, private
FileMapInfo* mapinfo = FileMapInfo::current_info();
if (!mapinfo->remap_shared_readonly_as_readwrite()) {
return false;
}
_remapped_readwrite = true;
}
return true;
}
void MetaspaceShared::report_out_of_space(const char* name, size_t needed_bytes) {
// This is highly unlikely to happen on 64-bits because we have reserved a 4GB space.
// On 32-bit we reserve only 256MB so you could run out of space with 100,000 classes
// or so.
_mc_region.print_out_of_space_msg(name, needed_bytes);
_rw_region.print_out_of_space_msg(name, needed_bytes);
_ro_region.print_out_of_space_msg(name, needed_bytes);
_md_region.print_out_of_space_msg(name, needed_bytes);
_od_region.print_out_of_space_msg(name, needed_bytes);
vm_exit_during_initialization(err_msg("Unable to allocate from '%s' region", name),
"Please reduce the number of shared classes.");
}