JDK14/Java14源码在线阅读
/*
* Copyright (c) 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/classLoaderData.inline.hpp"
#include "classfile/symbolTable.hpp"
#include "classfile/systemDictionary.hpp"
#include "classfile/systemDictionaryShared.hpp"
#include "logging/log.hpp"
#include "memory/archiveUtils.inline.hpp"
#include "memory/dynamicArchive.hpp"
#include "memory/metadataFactory.hpp"
#include "memory/metaspace.hpp"
#include "memory/metaspaceClosure.hpp"
#include "memory/metaspaceShared.hpp"
#include "memory/resourceArea.hpp"
#include "oops/compressedOops.hpp"
#include "oops/objArrayKlass.hpp"
#include "prims/jvmtiRedefineClasses.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/os.inline.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/vmThread.hpp"
#include "runtime/vmOperations.hpp"
#include "utilities/bitMap.inline.hpp"
#ifndef O_BINARY // if defined (Win32) use binary files.
#define O_BINARY 0 // otherwise do nothing.
#endif
class DynamicArchiveBuilder : ResourceObj {
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,
DynamicArchiveBuilder::my_hash, // solaris compiler doesn't like: primitive_hash<address>
DynamicArchiveBuilder::my_equals, // solaris compiler doesn't like: primitive_equals<address>
16384, ResourceObj::C_HEAP> RelocationTable;
RelocationTable _new_loc_table;
static intx _buffer_to_target_delta;
DumpRegion* _current_dump_space;
static size_t reserve_alignment() {
return Metaspace::reserve_alignment();
}
static const int _total_dump_regions = 3;
int _num_dump_regions_used;
public:
void mark_pointer(address* ptr_loc) {
ArchivePtrMarker::mark_pointer(ptr_loc);
}
DumpRegion* current_dump_space() const {
return _current_dump_space;
}
bool is_in_buffer_space(address p) const {
return (_alloc_bottom <= p && p < (address)current_dump_space()->top());
}
template <typename T> bool is_in_target_space(T target_obj) const {
address buff_obj = address(target_obj) - _buffer_to_target_delta;
return is_in_buffer_space(buff_obj);
}
template <typename T> bool is_in_buffer_space(T obj) const {
return is_in_buffer_space(address(obj));
}
template <typename T> T to_target_no_check(T obj) const {
return (T)(address(obj) + _buffer_to_target_delta);
}
template <typename T> T to_target(T obj) const {
assert(is_in_buffer_space(obj), "must be");
return (T)(address(obj) + _buffer_to_target_delta);
}
template <typename T> T get_new_loc(T obj) {
address* pp = _new_loc_table.get((address)obj);
if (pp == NULL) {
// Excluded klasses are not copied
return NULL;
} else {
return (T)*pp;
}
}
address get_new_loc(MetaspaceClosure::Ref* ref) {
return get_new_loc(ref->obj());
}
template <typename T> bool has_new_loc(T obj) {
address* pp = _new_loc_table.get((address)obj);
return pp != NULL;
}
static int dynamic_dump_method_comparator(Method* a, Method* b) {
Symbol* a_name = a->name();
Symbol* b_name = b->name();
if (a_name == b_name) {
return 0;
}
if (!MetaspaceShared::is_in_shared_metaspace(a_name)) {
// a_name points to a Symbol in the top archive.
// When this method is called, a_name is still pointing to the output space.
// Translate it to point to the output space, so that it can be compared with
// Symbols in the base archive.
a_name = (Symbol*)(address(a_name) + _buffer_to_target_delta);
}
if (!MetaspaceShared::is_in_shared_metaspace(b_name)) {
b_name = (Symbol*)(address(b_name) + _buffer_to_target_delta);
}
return a_name->fast_compare(b_name);
}
protected:
enum FollowMode {
make_a_copy, point_to_it, set_to_null
};
public:
void copy(MetaspaceClosure::Ref* ref, bool read_only) {
int bytes = ref->size() * BytesPerWord;
address old_obj = ref->obj();
address new_obj = copy_impl(ref, read_only, bytes);
assert(new_obj != NULL, "must be");
assert(new_obj != old_obj, "must be");
bool isnew = _new_loc_table.put(old_obj, new_obj);
assert(isnew, "must be");
}
// Make a shallow copy of each eligible MetaspaceObj into the buffer.
class ShallowCopier: public UniqueMetaspaceClosure {
DynamicArchiveBuilder* _builder;
bool _read_only;
public:
ShallowCopier(DynamicArchiveBuilder* shuffler, bool read_only)
: _builder(shuffler), _read_only(read_only) {}
virtual bool do_unique_ref(Ref* orig_obj, bool read_only) {
// This method gets called on each *original* object
// reachable from _builder->iterate_roots(). Each orig_obj is
// called exactly once.
FollowMode mode = _builder->follow_ref(orig_obj);
if (mode == point_to_it) {
if (read_only == _read_only) {
log_debug(cds, dynamic)("ptr : " PTR_FORMAT " %s", p2i(orig_obj->obj()),
MetaspaceObj::type_name(orig_obj->msotype()));
address p = orig_obj->obj();
bool isnew = _builder->_new_loc_table.put(p, p);
assert(isnew, "must be");
}
return false;
}
if (mode == set_to_null) {
log_debug(cds, dynamic)("nul : " PTR_FORMAT " %s", p2i(orig_obj->obj()),
MetaspaceObj::type_name(orig_obj->msotype()));
return false;
}
if (read_only == _read_only) {
// Make a shallow copy of orig_obj in a buffer (maintained
// by copy_impl in a subclass of DynamicArchiveBuilder).
_builder->copy(orig_obj, read_only);
}
return true;
}
};
// Relocate all embedded pointer fields within a MetaspaceObj's shallow copy
class ShallowCopyEmbeddedRefRelocator: public UniqueMetaspaceClosure {
DynamicArchiveBuilder* _builder;
public:
ShallowCopyEmbeddedRefRelocator(DynamicArchiveBuilder* shuffler)
: _builder(shuffler) {}
// This method gets called on each *original* object reachable
// from _builder->iterate_roots(). Each orig_obj is
// called exactly once.
virtual bool do_unique_ref(Ref* orig_ref, bool read_only) {
FollowMode mode = _builder->follow_ref(orig_ref);
if (mode == point_to_it) {
// We did not make a copy of this object
// and we have nothing to update
assert(_builder->get_new_loc(orig_ref) == NULL ||
_builder->get_new_loc(orig_ref) == orig_ref->obj(), "must be");
return false;
}
if (mode == set_to_null) {
// We did not make a copy of this object
// and we have nothing to update
assert(!_builder->has_new_loc(orig_ref->obj()), "must not be copied or pointed to");
return false;
}
// - orig_obj points to the original object.
// - new_obj points to the shallow copy (created by ShallowCopier)
// of orig_obj. new_obj is NULL if the orig_obj is excluded
address orig_obj = orig_ref->obj();
address new_obj = _builder->get_new_loc(orig_ref);
assert(new_obj != orig_obj, "must be");
#ifdef ASSERT
if (new_obj == NULL) {
if (orig_ref->msotype() == MetaspaceObj::ClassType) {
Klass* k = (Klass*)orig_obj;
assert(k->is_instance_klass() &&
SystemDictionaryShared::is_excluded_class(InstanceKlass::cast(k)),
"orig_obj must be excluded Class");
}
}
#endif
log_debug(cds, dynamic)("Relocating " PTR_FORMAT " %s", p2i(new_obj),
MetaspaceObj::type_name(orig_ref->msotype()));
if (new_obj != NULL) {
EmbeddedRefUpdater updater(_builder, orig_obj, new_obj);
orig_ref->metaspace_pointers_do(&updater);
}
return true; // keep recursing until every object is visited exactly once.
}
virtual void push_special(SpecialRef type, Ref* ref, intptr_t* p) {
assert(type == _method_entry_ref, "only special type allowed for now");
address obj = ref->obj();
address new_obj = _builder->get_new_loc(ref);
size_t offset = pointer_delta(p, obj, sizeof(u1));
intptr_t* new_p = (intptr_t*)(new_obj + offset);
assert(*p == *new_p, "must be a copy");
ArchivePtrMarker::mark_pointer((address*)new_p);
}
};
class EmbeddedRefUpdater: public MetaspaceClosure {
DynamicArchiveBuilder* _builder;
address _orig_obj;
address _new_obj;
public:
EmbeddedRefUpdater(DynamicArchiveBuilder* shuffler, address orig_obj, address new_obj) :
_builder(shuffler), _orig_obj(orig_obj), _new_obj(new_obj) {}
// This method gets called once for each pointer field F of orig_obj.
// We update new_obj->F to point to the new location of orig_obj->F.
//
// Example: Klass* 0x100 is copied to 0x400
// Symbol* 0x200 is copied to 0x500
//
// Let orig_obj == 0x100; and
// new_obj == 0x400; and
// ((Klass*)orig_obj)->_name == 0x200;
// Then this function effectively assigns
// ((Klass*)new_obj)->_name = 0x500;
virtual bool do_ref(Ref* ref, bool read_only) {
address new_pointee = NULL;
if (ref->not_null()) {
address old_pointee = ref->obj();
FollowMode mode = _builder->follow_ref(ref);
if (mode == point_to_it) {
new_pointee = old_pointee;
} else if (mode == set_to_null) {
new_pointee = NULL;
} else {
new_pointee = _builder->get_new_loc(old_pointee);
}
}
const char* kind = MetaspaceObj::type_name(ref->msotype());
// offset of this field inside the original object
intx offset = (address)ref->addr() - _orig_obj;
_builder->update_pointer((address*)(_new_obj + offset), new_pointee, kind, offset);
// We can't mark the pointer here, because DynamicArchiveBuilder::sort_methods
// may re-layout the [iv]tables, which would change the offset(s) in an InstanceKlass
// that would contain pointers. Therefore, we must mark the pointers after
// sort_methods(), using PointerMarker.
return false; // Do not recurse.
}
};
class ExternalRefUpdater: public MetaspaceClosure {
DynamicArchiveBuilder* _builder;
public:
ExternalRefUpdater(DynamicArchiveBuilder* shuffler) : _builder(shuffler) {}
virtual bool do_ref(Ref* ref, bool read_only) {
// ref is a pointer that lives OUTSIDE of the buffer, but points to an object inside the buffer
if (ref->not_null()) {
address new_loc = _builder->get_new_loc(ref);
const char* kind = MetaspaceObj::type_name(ref->msotype());
_builder->update_pointer(ref->addr(), new_loc, kind, 0);
_builder->mark_pointer(ref->addr());
}
return false; // Do not recurse.
}
};
class PointerMarker: public UniqueMetaspaceClosure {
DynamicArchiveBuilder* _builder;
public:
PointerMarker(DynamicArchiveBuilder* shuffler) : _builder(shuffler) {}
virtual bool do_unique_ref(Ref* ref, bool read_only) {
if (_builder->is_in_buffer_space(ref->obj())) {
EmbeddedRefMarker ref_marker(_builder);
ref->metaspace_pointers_do(&ref_marker);
return true; // keep recursing until every buffered object is visited exactly once.
} else {
return false;
}
}
};
class EmbeddedRefMarker: public MetaspaceClosure {
DynamicArchiveBuilder* _builder;
public:
EmbeddedRefMarker(DynamicArchiveBuilder* shuffler) : _builder(shuffler) {}
virtual bool do_ref(Ref* ref, bool read_only) {
if (ref->not_null()) {
_builder->mark_pointer(ref->addr());
}
return false; // Do not recurse.
}
};
void update_pointer(address* addr, address value, const char* kind, uintx offset, bool is_mso_pointer=true) {
// Propagate the the mask bits to the new value -- see comments above MetaspaceClosure::obj()
if (is_mso_pointer) {
const uintx FLAG_MASK = 0x03;
uintx mask_bits = uintx(*addr) & FLAG_MASK;
value = (address)(uintx(value) | mask_bits);
}
if (*addr != value) {
log_debug(cds, dynamic)("Update (%18s*) %3d [" PTR_FORMAT "] " PTR_FORMAT " -> " PTR_FORMAT,
kind, int(offset), p2i(addr), p2i(*addr), p2i(value));
*addr = value;
}
}
private:
GrowableArray<Symbol*>* _symbols; // symbols to dump
GrowableArray<InstanceKlass*>* _klasses; // klasses to dump
void append(InstanceKlass* k) { _klasses->append(k); }
void append(Symbol* s) { _symbols->append(s); }
class GatherKlassesAndSymbols : public UniqueMetaspaceClosure {
DynamicArchiveBuilder* _builder;
bool _read_only;
public:
GatherKlassesAndSymbols(DynamicArchiveBuilder* builder)
: _builder(builder) {}
virtual bool do_unique_ref(Ref* ref, bool read_only) {
if (_builder->follow_ref(ref) != make_a_copy) {
return false;
}
if (ref->msotype() == MetaspaceObj::ClassType) {
Klass* klass = (Klass*)ref->obj();
assert(klass->is_klass(), "must be");
if (klass->is_instance_klass()) {
InstanceKlass* ik = InstanceKlass::cast(klass);
assert(!SystemDictionaryShared::is_excluded_class(ik), "must be");
_builder->append(ik);
_builder->_estimated_metsapceobj_bytes += BytesPerWord; // See RunTimeSharedClassInfo::get_for()
}
} else if (ref->msotype() == MetaspaceObj::SymbolType) {
_builder->append((Symbol*)ref->obj());
}
int bytes = ref->size() * BytesPerWord;
_builder->_estimated_metsapceobj_bytes += bytes;
return true;
}
};
FollowMode follow_ref(MetaspaceClosure::Ref *ref) {
address obj = ref->obj();
if (MetaspaceShared::is_in_shared_metaspace(obj)) {
// Don't dump existing shared metadata again.
return point_to_it;
} else if (ref->msotype() == MetaspaceObj::MethodDataType) {
return set_to_null;
} else {
if (ref->msotype() == MetaspaceObj::ClassType) {
Klass* klass = (Klass*)ref->obj();
assert(klass->is_klass(), "must be");
if (klass->is_instance_klass()) {
InstanceKlass* ik = InstanceKlass::cast(klass);
if (SystemDictionaryShared::is_excluded_class(ik)) {
ResourceMark rm;
log_debug(cds, dynamic)("Skipping class (excluded): %s", klass->external_name());
return set_to_null;
}
} else if (klass->is_array_klass()) {
// Don't support archiving of array klasses for now.
ResourceMark rm;
log_debug(cds, dynamic)("Skipping class (array): %s", klass->external_name());
return set_to_null;
}
}
return make_a_copy;
}
}
address copy_impl(MetaspaceClosure::Ref* ref, bool read_only, int bytes) {
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.
address obj = ref->obj();
Klass* klass = (Klass*)obj;
if (klass->is_instance_klass()) {
SystemDictionaryShared::validate_before_archiving(InstanceKlass::cast(klass));
current_dump_space()->allocate(sizeof(address), BytesPerWord);
}
}
address p = (address)current_dump_space()->allocate(bytes);
address obj = ref->obj();
log_debug(cds, dynamic)("COPY: " PTR_FORMAT " ==> " PTR_FORMAT " %5d %s",
p2i(obj), p2i(p), bytes,
MetaspaceObj::type_name(ref->msotype()));
memcpy(p, obj, bytes);
intptr_t* cloned_vtable = MetaspaceShared::fix_cpp_vtable_for_dynamic_archive(ref->msotype(), p);
if (cloned_vtable != NULL) {
update_pointer((address*)p, (address)cloned_vtable, "vtb", 0, /*is_mso_pointer*/false);
mark_pointer((address*)p);
}
return (address)p;
}
DynamicArchiveHeader *_header;
address _alloc_bottom;
address _last_verified_top;
size_t _other_region_used_bytes;
// Conservative estimate for number of bytes needed for:
size_t _estimated_metsapceobj_bytes; // all archived MetsapceObj's.
size_t _estimated_hashtable_bytes; // symbol table and dictionaries
size_t _estimated_trampoline_bytes; // method entry trampolines
size_t estimate_archive_size();
size_t estimate_trampoline_size();
size_t estimate_class_file_size();
address reserve_space_and_init_buffer_to_target_delta();
void init_header(address addr);
void release_header();
void make_trampolines();
void make_klasses_shareable();
void sort_methods(InstanceKlass* ik) const;
void set_symbols_permanent();
void relocate_buffer_to_target();
void write_archive(char* serialized_data_start);
void write_regions(FileMapInfo* dynamic_info);
void init_first_dump_space(address reserved_bottom) {
address first_space_base = reserved_bottom;
DumpRegion* rw_space = MetaspaceShared::read_write_dump_space();
MetaspaceShared::init_shared_dump_space(rw_space, first_space_base);
_current_dump_space = rw_space;
_last_verified_top = first_space_base;
_num_dump_regions_used = 1;
}
public:
DynamicArchiveBuilder() {
_klasses = new (ResourceObj::C_HEAP, mtClass) GrowableArray<InstanceKlass*>(100, true, mtInternal);
_symbols = new (ResourceObj::C_HEAP, mtClass) GrowableArray<Symbol*>(1000, true, mtInternal);
_estimated_metsapceobj_bytes = 0;
_estimated_hashtable_bytes = 0;
_estimated_trampoline_bytes = 0;
_num_dump_regions_used = 0;
}
void start_dump_space(DumpRegion* next) {
address bottom = _last_verified_top;
address top = (address)(current_dump_space()->top());
_other_region_used_bytes += size_t(top - bottom);
MetaspaceShared::pack_dump_space(current_dump_space(), next, MetaspaceShared::shared_rs());
_current_dump_space = next;
_num_dump_regions_used ++;
_last_verified_top = (address)(current_dump_space()->top());
}
void verify_estimate_size(size_t estimate, const char* which) {
address bottom = _last_verified_top;
address top = (address)(current_dump_space()->top());
size_t used = size_t(top - bottom) + _other_region_used_bytes;
int diff = int(estimate) - int(used);
log_info(cds)("%s estimate = " SIZE_FORMAT " used = " SIZE_FORMAT "; diff = %d bytes", which, estimate, used, diff);
assert(diff >= 0, "Estimate is too small");
_last_verified_top = top;
_other_region_used_bytes = 0;
}
// Do this before and after the archive dump to see if any corruption
// is caused by dynamic dumping.
void verify_universe(const char* info) {
if (VerifyBeforeExit) {
log_info(cds)("Verify %s", info);
HandleMark hm;
// Among other things, this ensures that Eden top is correct.
Universe::heap()->prepare_for_verify();
Universe::verify(info);
}
}
void doit() {
verify_universe("Before CDS dynamic dump");
DEBUG_ONLY(SystemDictionaryShared::NoClassLoadingMark nclm);
SystemDictionaryShared::check_excluded_classes();
{
ResourceMark rm;
GatherKlassesAndSymbols gatherer(this);
SystemDictionaryShared::dumptime_classes_do(&gatherer);
SymbolTable::metaspace_pointers_do(&gatherer);
FileMapInfo::metaspace_pointers_do(&gatherer);
gatherer.finish();
}
// rw space starts ...
address reserved_bottom = reserve_space_and_init_buffer_to_target_delta();
init_header(reserved_bottom);
CHeapBitMap ptrmap;
ArchivePtrMarker::initialize(&ptrmap, (address*)reserved_bottom, (address*)current_dump_space()->top());
verify_estimate_size(sizeof(DynamicArchiveHeader), "header");
log_info(cds, dynamic)("Copying %d klasses and %d symbols",
_klasses->length(), _symbols->length());
{
assert(current_dump_space() == MetaspaceShared::read_write_dump_space(),
"Current dump space is not rw space");
// shallow-copy RW objects, if necessary
ResourceMark rm;
ShallowCopier rw_copier(this, false);
iterate_roots(&rw_copier);
}
// ro space starts ...
DumpRegion* ro_space = MetaspaceShared::read_only_dump_space();
{
start_dump_space(ro_space);
// shallow-copy RO objects, if necessary
ResourceMark rm;
ShallowCopier ro_copier(this, true);
iterate_roots(&ro_copier);
}
{
log_info(cds)("Relocating embedded pointers ... ");
ResourceMark rm;
ShallowCopyEmbeddedRefRelocator emb_reloc(this);
iterate_roots(&emb_reloc);
}
{
log_info(cds)("Relocating external roots ... ");
ResourceMark rm;
ExternalRefUpdater ext_reloc(this);
iterate_roots(&ext_reloc);
}
verify_estimate_size(_estimated_metsapceobj_bytes, "MetaspaceObjs");
char* serialized_data_start;
{
set_symbols_permanent();
// Write the symbol table and system dictionaries to the RO space.
// Note that these tables still point to the *original* objects
// (because they were not processed by ExternalRefUpdater), so
// they would need to call DynamicArchive::original_to_target() to
// get the correct addresses.
assert(current_dump_space() == ro_space, "Must be RO space");
SymbolTable::write_to_archive(false);
SystemDictionaryShared::write_to_archive(false);
serialized_data_start = ro_space->top();
WriteClosure wc(ro_space);
SymbolTable::serialize_shared_table_header(&wc, false);
SystemDictionaryShared::serialize_dictionary_headers(&wc, false);
}
verify_estimate_size(_estimated_hashtable_bytes, "Hashtables");
// mc space starts ...
{
start_dump_space(MetaspaceShared::misc_code_dump_space());
make_trampolines();
}
verify_estimate_size(_estimated_trampoline_bytes, "Trampolines");
make_klasses_shareable();
{
log_info(cds)("Final relocation of pointers ... ");
ResourceMark rm;
PointerMarker marker(this);
iterate_roots(&marker);
relocate_buffer_to_target();
}
write_archive(serialized_data_start);
release_header();
assert(_num_dump_regions_used == _total_dump_regions, "must be");
verify_universe("After CDS dynamic dump");
}
void iterate_roots(MetaspaceClosure* it) {
int i;
int num_klasses = _klasses->length();
for (i = 0; i < num_klasses; i++) {
it->push(&_klasses->at(i));
}
int num_symbols = _symbols->length();
for (i = 0; i < num_symbols; i++) {
it->push(&_symbols->at(i));
}
FileMapInfo::metaspace_pointers_do(it);
// Do not call these again, as we have already collected all the classes and symbols
// that we want to archive. Also, these calls would corrupt the tables when
// ExternalRefUpdater is used.
//
// SystemDictionaryShared::dumptime_classes_do(it);
// SymbolTable::metaspace_pointers_do(it);
it->finish();
}
};
intx DynamicArchiveBuilder::_buffer_to_target_delta;
size_t DynamicArchiveBuilder::estimate_archive_size() {
// size of the symbol table and two dictionaries, plus the RunTimeSharedClassInfo's
_estimated_hashtable_bytes = 0;
_estimated_hashtable_bytes += SymbolTable::estimate_size_for_archive();
_estimated_hashtable_bytes += SystemDictionaryShared::estimate_size_for_archive();
_estimated_trampoline_bytes = estimate_trampoline_size();
size_t total = 0;
total += _estimated_metsapceobj_bytes;
total += _estimated_hashtable_bytes;
total += _estimated_trampoline_bytes;
// allow fragmentation at the end of each dump region
total += _total_dump_regions * reserve_alignment();
return align_up(total, reserve_alignment());
}
address DynamicArchiveBuilder::reserve_space_and_init_buffer_to_target_delta() {
size_t total = estimate_archive_size();
ReservedSpace rs = MetaspaceShared::reserve_shared_space(total);
if (!rs.is_reserved()) {
log_error(cds, dynamic)("Failed to reserve %d bytes of output buffer.", (int)total);
vm_direct_exit(0);
}
address buffer_base = (address)rs.base();
log_info(cds, dynamic)("Reserved output buffer space at : " PTR_FORMAT " [%d bytes]",
p2i(buffer_base), (int)total);
MetaspaceShared::set_shared_rs(rs);
// At run time, we will mmap the dynamic archive at target_space_bottom.
// However, at dump time, we may not be able to write into the target_space,
// as it's occupied by dynamically loaded Klasses. So we allocate a buffer
// at an arbitrary location chosen by the OS. We will write all the dynamically
// archived classes into this buffer. At the final stage of dumping, we relocate
// all pointers that are inside the buffer_space to point to their (runtime)
// target location inside thetarget_space.
address target_space_bottom =
(address)align_up(MetaspaceShared::shared_metaspace_top(), reserve_alignment());
_buffer_to_target_delta = intx(target_space_bottom) - intx(buffer_base);
log_info(cds, dynamic)("Target archive space at : " PTR_FORMAT, p2i(target_space_bottom));
log_info(cds, dynamic)("Buffer-space to target-space delta : " PTR_FORMAT, p2i((address)_buffer_to_target_delta));
return buffer_base;
}
void DynamicArchiveBuilder::init_header(address reserved_bottom) {
_alloc_bottom = reserved_bottom;
_last_verified_top = reserved_bottom;
_other_region_used_bytes = 0;
init_first_dump_space(reserved_bottom);
FileMapInfo* mapinfo = new FileMapInfo(false);
assert(FileMapInfo::dynamic_info() == mapinfo, "must be");
_header = mapinfo->dynamic_header();
Thread* THREAD = Thread::current();
FileMapInfo* base_info = FileMapInfo::current_info();
_header->set_base_header_crc(base_info->crc());
for (int i = 0; i < MetaspaceShared::n_regions; i++) {
_header->set_base_region_crc(i, base_info->space_crc(i));
}
_header->populate(base_info, os::vm_allocation_granularity());
}
void DynamicArchiveBuilder::release_header() {
// We temporarily allocated a dynamic FileMapInfo for dumping, which makes it appear we
// have mapped a dynamic archive, but we actually have not. We are in a safepoint now.
// Let's free it so that if class loading happens after we leave the safepoint, nothing
// bad will happen.
assert(SafepointSynchronize::is_at_safepoint(), "must be");
FileMapInfo *mapinfo = FileMapInfo::dynamic_info();
assert(mapinfo != NULL && _header == mapinfo->dynamic_header(), "must be");
delete mapinfo;
assert(!DynamicArchive::is_mapped(), "must be");
_header = NULL;
}
size_t DynamicArchiveBuilder::estimate_trampoline_size() {
size_t total = 0;
size_t each_method_bytes =
align_up(SharedRuntime::trampoline_size(), BytesPerWord) +
align_up(sizeof(AdapterHandlerEntry*), BytesPerWord);
for (int i = 0; i < _klasses->length(); i++) {
InstanceKlass* ik = _klasses->at(i);
Array<Method*>* methods = ik->methods();
total += each_method_bytes * methods->length();
}
if (total == 0) {
// We have nothing to archive, but let's avoid having an empty region.
total = SharedRuntime::trampoline_size();
}
return total;
}
void DynamicArchiveBuilder::make_trampolines() {
for (int i = 0; i < _klasses->length(); i++) {
InstanceKlass* ik = _klasses->at(i);
Array<Method*>* methods = ik->methods();
for (int j = 0; j < methods->length(); j++) {
Method* m = methods->at(j);
address c2i_entry_trampoline =
(address)MetaspaceShared::misc_code_space_alloc(SharedRuntime::trampoline_size());
m->set_from_compiled_entry(to_target(c2i_entry_trampoline));
AdapterHandlerEntry** adapter_trampoline =
(AdapterHandlerEntry**)MetaspaceShared::misc_code_space_alloc(sizeof(AdapterHandlerEntry*));
*adapter_trampoline = NULL;
m->set_adapter_trampoline(to_target(adapter_trampoline));
}
}
if (MetaspaceShared::misc_code_dump_space()->used() == 0) {
// We have nothing to archive, but let's avoid having an empty region.
MetaspaceShared::misc_code_space_alloc(SharedRuntime::trampoline_size());
}
}
void DynamicArchiveBuilder::make_klasses_shareable() {
int i, count = _klasses->length();
InstanceKlass::disable_method_binary_search();
for (i = 0; i < count; i++) {
InstanceKlass* ik = _klasses->at(i);
sort_methods(ik);
}
for (i = 0; i < count; i++) {
InstanceKlass* ik = _klasses->at(i);
ClassLoaderData *cld = ik->class_loader_data();
if (cld->is_boot_class_loader_data()) {
ik->set_class_loader_type(ClassLoader::BOOT_LOADER);
}
else if (cld->is_platform_class_loader_data()) {
ik->set_class_loader_type(ClassLoader::PLATFORM_LOADER);
}
else if (cld->is_system_class_loader_data()) {
ik->set_class_loader_type(ClassLoader::APP_LOADER);
}
MetaspaceShared::rewrite_nofast_bytecodes_and_calculate_fingerprints(Thread::current(), ik);
ik->remove_unshareable_info();
assert(ik->array_klasses() == NULL, "sanity");
if (log_is_enabled(Debug, cds, dynamic)) {
ResourceMark rm;
log_debug(cds, dynamic)("klasses[%4i] = " PTR_FORMAT " %s", i, p2i(to_target(ik)), ik->external_name());
}
}
}
// The address order of the copied Symbols may be different than when the original
// klasses were created. Re-sort all the tables. See Method::sort_methods().
void DynamicArchiveBuilder::sort_methods(InstanceKlass* ik) const {
assert(ik != NULL, "DynamicArchiveBuilder currently doesn't support dumping the base archive");
if (MetaspaceShared::is_in_shared_metaspace(ik)) {
// We have reached a supertype that's already in the base archive
return;
}
if (ik->java_mirror() == NULL) {
// NULL mirror means this class has already been visited and methods are already sorted
return;
}
ik->remove_java_mirror();
if (log_is_enabled(Debug, cds, dynamic)) {
ResourceMark rm;
log_debug(cds, dynamic)("sorting methods for " PTR_FORMAT " %s", p2i(to_target(ik)), ik->external_name());
}
// Make sure all supertypes have been sorted
sort_methods(ik->java_super());
Array<InstanceKlass*>* interfaces = ik->local_interfaces();
int len = interfaces->length();
for (int i = 0; i < len; i++) {
sort_methods(interfaces->at(i));
}
#ifdef ASSERT
if (ik->methods() != NULL) {
for (int m = 0; m < ik->methods()->length(); m++) {
Symbol* name = ik->methods()->at(m)->name();
assert(MetaspaceShared::is_in_shared_metaspace(name) || is_in_buffer_space(name), "must be");
}
}
if (ik->default_methods() != NULL) {
for (int m = 0; m < ik->default_methods()->length(); m++) {
Symbol* name = ik->default_methods()->at(m)->name();
assert(MetaspaceShared::is_in_shared_metaspace(name) || is_in_buffer_space(name), "must be");
}
}
#endif
Thread* THREAD = Thread::current();
Method::sort_methods(ik->methods(), /*set_idnums=*/true, dynamic_dump_method_comparator);
if (ik->default_methods() != NULL) {
Method::sort_methods(ik->default_methods(), /*set_idnums=*/false, dynamic_dump_method_comparator);
}
ik->vtable().initialize_vtable(true, THREAD); assert(!HAS_PENDING_EXCEPTION, "cannot fail");
ik->itable().initialize_itable(true, THREAD); assert(!HAS_PENDING_EXCEPTION, "cannot fail");
}
void DynamicArchiveBuilder::set_symbols_permanent() {
int count = _symbols->length();
for (int i=0; i<count; i++) {
Symbol* s = _symbols->at(i);
s->set_permanent();
if (log_is_enabled(Trace, cds, dynamic)) {
ResourceMark rm;
log_trace(cds, dynamic)("symbols[%4i] = " PTR_FORMAT " %s", i, p2i(to_target(s)), s->as_quoted_ascii());
}
}
}
class RelocateBufferToTarget: public BitMapClosure {
DynamicArchiveBuilder *_builder;
address* _buffer_bottom;
intx _buffer_to_target_delta;
public:
RelocateBufferToTarget(DynamicArchiveBuilder* builder, address* bottom, intx delta) :
_builder(builder), _buffer_bottom(bottom), _buffer_to_target_delta(delta) {}
bool do_bit(size_t offset) {
address* p = _buffer_bottom + offset;
assert(_builder->is_in_buffer_space(p), "pointer must live in buffer space");
address old_ptr = *p;
if (_builder->is_in_buffer_space(old_ptr)) {
address new_ptr = old_ptr + _buffer_to_target_delta;
log_trace(cds, dynamic)("Final patch: @%6d [" PTR_FORMAT " -> " PTR_FORMAT "] " PTR_FORMAT " => " PTR_FORMAT,
(int)offset, p2i(p), p2i(_builder->to_target(p)),
p2i(old_ptr), p2i(new_ptr));
*p = new_ptr;
}
return true; // keep iterating
}
};
void DynamicArchiveBuilder::relocate_buffer_to_target() {
RelocateBufferToTarget patcher(this, (address*)_alloc_bottom, _buffer_to_target_delta);
ArchivePtrMarker::ptrmap()->iterate(&patcher);
Array<u8>* table = FileMapInfo::shared_path_table().table();
SharedPathTable runtime_table(to_target(table), FileMapInfo::shared_path_table().size());
_header->set_shared_path_table(runtime_table);
address relocatable_base = (address)SharedBaseAddress;
address relocatable_end = (address)(current_dump_space()->top()) + _buffer_to_target_delta;
intx addr_delta = MetaspaceShared::final_delta();
if (addr_delta == 0) {
ArchivePtrMarker::compact(relocatable_base, relocatable_end);
} else {
// The base archive is NOT mapped at Arguments::default_SharedBaseAddress() (due to ASLR).
// This means that the current content of the dynamic archive is based on a random
// address. Let's relocate all the pointers, so that it can be mapped to
// Arguments::default_SharedBaseAddress() without runtime relocation.
//
// Note: both the base and dynamic archive are written with
// FileMapHeader::_shared_base_address == Arguments::default_SharedBaseAddress()
// Patch all pointers that are marked by ptrmap within this region,
// where we have just dumped all the metaspace data.
address patch_base = (address)_alloc_bottom;
address patch_end = (address)current_dump_space()->top();
// the current value of the pointers to be patched must be within this
// range (i.e., must point to either the top archive (as currently mapped), or to the
// (targeted address of) the top archive)
address valid_old_base = relocatable_base;
address valid_old_end = relocatable_end;
size_t base_plus_top_size = valid_old_end - valid_old_base;
size_t top_size = patch_end - patch_base;
size_t base_size = base_plus_top_size - top_size;
assert(base_plus_top_size > base_size, "no overflow");
assert(base_plus_top_size > top_size, "no overflow");
// after patching, the pointers must point inside this range
// (the requested location of the archive, as mapped at runtime).
address valid_new_base = (address)Arguments::default_SharedBaseAddress();
address valid_new_end = valid_new_base + base_plus_top_size;
log_debug(cds)("Relocating archive from [" INTPTR_FORMAT " - " INTPTR_FORMAT "] to "
"[" INTPTR_FORMAT " - " INTPTR_FORMAT "], delta = " INTX_FORMAT " bytes",
p2i(patch_base + base_size), p2i(patch_end),
p2i(valid_new_base + base_size), p2i(valid_new_end), addr_delta);
SharedDataRelocator<true> patcher((address*)patch_base, (address*)patch_end, valid_old_base, valid_old_end,
valid_new_base, valid_new_end, addr_delta, ArchivePtrMarker::ptrmap());
ArchivePtrMarker::ptrmap()->iterate(&patcher);
ArchivePtrMarker::compact(patcher.max_non_null_offset());
}
}
void DynamicArchiveBuilder::write_regions(FileMapInfo* dynamic_info) {
dynamic_info->write_region(MetaspaceShared::rw,
MetaspaceShared::read_write_dump_space()->base(),
MetaspaceShared::read_write_dump_space()->used(),
/*read_only=*/false,/*allow_exec=*/false);
dynamic_info->write_region(MetaspaceShared::ro,
MetaspaceShared::read_only_dump_space()->base(),
MetaspaceShared::read_only_dump_space()->used(),
/*read_only=*/true, /*allow_exec=*/false);
dynamic_info->write_region(MetaspaceShared::mc,
MetaspaceShared::misc_code_dump_space()->base(),
MetaspaceShared::misc_code_dump_space()->used(),
/*read_only=*/false,/*allow_exec=*/true);
dynamic_info->write_bitmap_region(ArchivePtrMarker::ptrmap());
}
void DynamicArchiveBuilder::write_archive(char* serialized_data_start) {
int num_klasses = _klasses->length();
int num_symbols = _symbols->length();
_header->set_serialized_data_start(to_target(serialized_data_start));
FileMapInfo* dynamic_info = FileMapInfo::dynamic_info();
assert(dynamic_info != NULL, "Sanity");
// Now write the archived data including the file offsets.
const char* archive_name = Arguments::GetSharedDynamicArchivePath();
dynamic_info->open_for_write(archive_name);
write_regions(dynamic_info);
dynamic_info->set_final_requested_base((char*)Arguments::default_SharedBaseAddress());
dynamic_info->set_header_crc(dynamic_info->compute_header_crc());
dynamic_info->write_header();
dynamic_info->close();
address base = to_target(_alloc_bottom);
address top = address(current_dump_space()->top()) + _buffer_to_target_delta;
size_t file_size = pointer_delta(top, base, sizeof(char));
base += MetaspaceShared::final_delta();
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