7032129: Native memory usage grow unexpectedly for vm/oom/*InternedString tests
Reviewed-by: kvn, kamg, jcoomes
/*
* Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "classfile/javaClasses.hpp"
#include "classfile/loaderConstraints.hpp"
#include "classfile/symbolTable.hpp"
#include "classfile/systemDictionary.hpp"
#include "gc_implementation/shared/spaceDecorator.hpp"
#include "memory/classify.hpp"
#include "memory/filemap.hpp"
#include "memory/oopFactory.hpp"
#include "memory/resourceArea.hpp"
#include "oops/methodDataOop.hpp"
#include "oops/oop.inline.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/signature.hpp"
#include "runtime/vmThread.hpp"
#include "runtime/vm_operations.hpp"
#include "utilities/copy.hpp"
// Closure to set up the fingerprint field for all methods.
class FingerprintMethodsClosure: public ObjectClosure {
public:
void do_object(oop obj) {
if (obj->is_method()) {
methodOop mobj = (methodOop)obj;
ResourceMark rm;
(new Fingerprinter(mobj))->fingerprint();
}
}
};
// Closure to set the hash value (String.hash field) in all of the
// String objects in the heap. Setting the hash value is not required.
// However, setting the value in advance prevents the value from being
// written later, increasing the likelihood that the shared page contain
// the hash can be shared.
//
// NOTE THAT the algorithm in StringTable::hash_string() MUST MATCH the
// algorithm in java.lang.String.hashCode().
class StringHashCodeClosure: public OopClosure {
private:
Thread* THREAD;
int hash_offset;
public:
StringHashCodeClosure(Thread* t) {
THREAD = t;
hash_offset = java_lang_String::hash_offset_in_bytes();
}
void do_oop(oop* p) {
if (p != NULL) {
oop obj = *p;
if (obj->klass() == SystemDictionary::String_klass()) {
int hash = java_lang_String::hash_string(obj);
obj->int_field_put(hash_offset, hash);
}
}
}
void do_oop(narrowOop* p) { ShouldNotReachHere(); }
};
// Remove data from objects which should not appear in the shared file
// (as it pertains only to the current JVM).
class RemoveUnshareableInfoClosure : public ObjectClosure {
public:
void do_object(oop obj) {
// Zap data from the objects which is pertains only to this JVM. We
// want that data recreated in new JVMs when the shared file is used.
if (obj->is_method()) {
((methodOop)obj)->remove_unshareable_info();
}
else if (obj->is_klass()) {
Klass::cast((klassOop)obj)->remove_unshareable_info();
}
// Don't save compiler related special oops (shouldn't be any yet).
if (obj->is_methodData() || obj->is_compiledICHolder()) {
ShouldNotReachHere();
}
}
};
static bool mark_object(oop obj) {
if (obj != NULL &&
!obj->is_shared() &&
!obj->is_forwarded() &&
!obj->is_gc_marked()) {
obj->set_mark(markOopDesc::prototype()->set_marked());
return true;
}
return false;
}
class MoveSymbols : public SymbolClosure {
private:
char* _start;
char* _end;
char* _top;
int _count;
bool in_shared_space(Symbol* sym) const {
return (char*)sym >= _start && (char*)sym < _end;
}
Symbol* get_shared_copy(Symbol* sym) {
return sym->refcount() > 0 ? NULL : (Symbol*)(_start - sym->refcount());
}
Symbol* make_shared_copy(Symbol* sym) {
Symbol* new_sym = (Symbol*)_top;
int size = sym->object_size();
_top += size * HeapWordSize;
if (_top <= _end) {
Copy::disjoint_words((HeapWord*)sym, (HeapWord*)new_sym, size);
// Encode a reference to the copy as a negative distance from _start
// When a symbol is being copied to a shared space
// during CDS archive creation, the original symbol is marked
// as relocated by putting a negative value to its _refcount field,
// This value is also used to find where exactly the shared copy is
// (see MoveSymbols::get_shared_copy), so that the other references
// to this symbol could be changed to point to the shared copy.
sym->_refcount = (int)(_start - (char*)new_sym);
// Mark the symbol in the shared archive as immortal so it is read only
// and not refcounted.
new_sym->_refcount = -1;
_count++;
} else {
report_out_of_shared_space(SharedMiscData);
}
return new_sym;
}
public:
MoveSymbols(char* top, char* end) :
_start(top), _end(end), _top(top), _count(0) { }
char* get_top() const { return _top; }
int count() const { return _count; }
void do_symbol(Symbol** p) {
Symbol* sym = load_symbol(p);
if (sym != NULL && !in_shared_space(sym)) {
Symbol* new_sym = get_shared_copy(sym);
if (new_sym == NULL) {
// The symbol has not been relocated yet; copy it to _top address
assert(sym->refcount() > 0, "should have positive reference count");
new_sym = make_shared_copy(sym);
}
// Make the reference point to the shared copy of the symbol
store_symbol(p, new_sym);
}
}
};
// Closure: mark objects closure.
class MarkObjectsOopClosure : public OopClosure {
public:
void do_oop(oop* p) { mark_object(*p); }
void do_oop(narrowOop* p) { ShouldNotReachHere(); }
};
class MarkObjectsSkippingKlassesOopClosure : public OopClosure {
public:
void do_oop(oop* pobj) {
oop obj = *pobj;
if (obj != NULL &&
!obj->is_klass()) {
mark_object(obj);
}
}
void do_oop(narrowOop* pobj) { ShouldNotReachHere(); }
};
static void mark_object_recursive_skipping_klasses(oop obj) {
mark_object(obj);
if (obj != NULL) {
MarkObjectsSkippingKlassesOopClosure mark_all;
obj->oop_iterate(&mark_all);
}
}
// Closure: mark common read-only objects
class MarkCommonReadOnly : public ObjectClosure {
private:
MarkObjectsOopClosure mark_all;
public:
void do_object(oop obj) {
// Mark all constMethod objects.
if (obj->is_constMethod()) {
mark_object(obj);
mark_object(constMethodOop(obj)->stackmap_data());
// Exception tables are needed by ci code during compilation.
mark_object(constMethodOop(obj)->exception_table());
}
// Mark objects referenced by klass objects which are read-only.
else if (obj->is_klass()) {
Klass* k = Klass::cast((klassOop)obj);
mark_object(k->secondary_supers());
// The METHODS() OBJARRAYS CANNOT BE MADE READ-ONLY, even though
// it is never modified. Otherwise, they will be pre-marked; the
// GC marking phase will skip them; and by skipping them will fail
// to mark the methods objects referenced by the array.
if (obj->blueprint()->oop_is_instanceKlass()) {
instanceKlass* ik = instanceKlass::cast((klassOop)obj);
mark_object(ik->method_ordering());
mark_object(ik->local_interfaces());
mark_object(ik->transitive_interfaces());
mark_object(ik->fields());
mark_object(ik->class_annotations());
mark_object_recursive_skipping_klasses(ik->fields_annotations());
mark_object_recursive_skipping_klasses(ik->methods_annotations());
mark_object_recursive_skipping_klasses(ik->methods_parameter_annotations());
mark_object_recursive_skipping_klasses(ik->methods_default_annotations());
typeArrayOop inner_classes = ik->inner_classes();
if (inner_classes != NULL) {
mark_object(inner_classes);
}
}
}
}
};
// Closure: find symbol references in Java Heap objects
class CommonSymbolsClosure : public ObjectClosure {
private:
SymbolClosure* _closure;
public:
CommonSymbolsClosure(SymbolClosure* closure) : _closure(closure) { }
void do_object(oop obj) {
// Traverse symbols referenced by method objects.
if (obj->is_method()) {
methodOop m = methodOop(obj);
constantPoolOop constants = m->constants();
_closure->do_symbol(constants->symbol_at_addr(m->name_index()));
_closure->do_symbol(constants->symbol_at_addr(m->signature_index()));
}
// Traverse symbols referenced by klass objects which are read-only.
else if (obj->is_klass()) {
Klass* k = Klass::cast((klassOop)obj);
k->shared_symbols_iterate(_closure);
if (obj->blueprint()->oop_is_instanceKlass()) {
instanceKlass* ik = instanceKlass::cast((klassOop)obj);
typeArrayOop inner_classes = ik->inner_classes();
if (inner_classes != NULL) {
constantPoolOop constants = ik->constants();
int n = inner_classes->length();
for (int i = 0; i < n; i += instanceKlass::inner_class_next_offset) {
int ioff = i + instanceKlass::inner_class_inner_name_offset;
int index = inner_classes->ushort_at(ioff);
if (index != 0) {
_closure->do_symbol(constants->symbol_at_addr(index));
}
}
}
}
}
// Traverse symbols referenced by other constantpool entries.
else if (obj->is_constantPool()) {
constantPoolOop(obj)->shared_symbols_iterate(_closure);
}
}
};
// Closure: mark char arrays used by strings
class MarkStringValues : public ObjectClosure {
private:
MarkObjectsOopClosure mark_all;
public:
void do_object(oop obj) {
// Character arrays referenced by String objects are read-only.
if (java_lang_String::is_instance(obj)) {
mark_object(java_lang_String::value(obj));
}
}
};
#ifdef DEBUG
// Closure: Check for objects left in the heap which have not been moved.
class CheckRemainingObjects : public ObjectClosure {
private:
int count;
public:
CheckRemainingObjects() {
count = 0;
}
void do_object(oop obj) {
if (!obj->is_shared() &&
!obj->is_forwarded()) {
++count;
if (Verbose) {
tty->print("Unreferenced object: ");
obj->print_on(tty);
}
}
}
void status() {
tty->print_cr("%d objects no longer referenced, not shared.", count);
}
};
#endif
// Closure: Mark remaining objects read-write, except Strings.
class MarkReadWriteObjects : public ObjectClosure {
private:
MarkObjectsOopClosure mark_objects;
public:
void do_object(oop obj) {
// The METHODS() OBJARRAYS CANNOT BE MADE READ-ONLY, even though
// it is never modified. Otherwise, they will be pre-marked; the
// GC marking phase will skip them; and by skipping them will fail
// to mark the methods objects referenced by the array.
if (obj->is_klass()) {
mark_object(obj);
Klass* k = klassOop(obj)->klass_part();
mark_object(k->java_mirror());
if (obj->blueprint()->oop_is_instanceKlass()) {
instanceKlass* ik = (instanceKlass*)k;
mark_object(ik->methods());
mark_object(ik->constants());
}
if (obj->blueprint()->oop_is_javaArray()) {
arrayKlass* ak = (arrayKlass*)k;
mark_object(ak->component_mirror());
}
return;
}
// Mark constantPool tags and the constantPoolCache.
else if (obj->is_constantPool()) {
constantPoolOop pool = constantPoolOop(obj);
mark_object(pool->cache());
pool->shared_tags_iterate(&mark_objects);
return;
}
// Mark all method objects.
if (obj->is_method()) {
mark_object(obj);
}
}
};
// Closure: Mark String objects read-write.
class MarkStringObjects : public ObjectClosure {
private:
MarkObjectsOopClosure mark_objects;
public:
void do_object(oop obj) {
// Mark String objects referenced by constant pool entries.
if (obj->is_constantPool()) {
constantPoolOop pool = constantPoolOop(obj);
pool->shared_strings_iterate(&mark_objects);
return;
}
}
};
// Move objects matching specified type (ie. lock_bits) to the specified
// space.
class MoveMarkedObjects : public ObjectClosure {
private:
OffsetTableContigSpace* _space;
bool _read_only;
public:
MoveMarkedObjects(OffsetTableContigSpace* space, bool read_only) {
_space = space;
_read_only = read_only;
}
void do_object(oop obj) {
if (obj->is_shared()) {
return;
}
if (obj->is_gc_marked() && obj->forwardee() == NULL) {
int s = obj->size();
oop sh_obj = (oop)_space->allocate(s);
if (sh_obj == NULL) {
report_out_of_shared_space(_read_only ? SharedReadOnly : SharedReadWrite);
}
if (PrintSharedSpaces && Verbose && WizardMode) {
tty->print_cr("\nMoveMarkedObjects: " PTR_FORMAT " -> " PTR_FORMAT " %s", obj, sh_obj,
(_read_only ? "ro" : "rw"));
}
Copy::aligned_disjoint_words((HeapWord*)obj, (HeapWord*)sh_obj, s);
obj->forward_to(sh_obj);
if (_read_only) {
// Readonly objects: set hash value to self pointer and make gc_marked.
sh_obj->forward_to(sh_obj);
} else {
sh_obj->init_mark();
}
}
}
};
static void mark_and_move(oop obj, MoveMarkedObjects* move) {
if (mark_object(obj)) move->do_object(obj);
}
enum order_policy {
OP_favor_startup = 0,
OP_balanced = 1,
OP_favor_runtime = 2
};
static void mark_and_move_for_policy(order_policy policy, oop obj, MoveMarkedObjects* move) {
if (SharedOptimizeColdStartPolicy >= policy) mark_and_move(obj, move);
}
class MarkAndMoveOrderedReadOnly : public ObjectClosure {
private:
MoveMarkedObjects *_move_ro;
public:
MarkAndMoveOrderedReadOnly(MoveMarkedObjects *move_ro) : _move_ro(move_ro) {}
void do_object(oop obj) {
if (obj->is_klass() && obj->blueprint()->oop_is_instanceKlass()) {
instanceKlass* ik = instanceKlass::cast((klassOop)obj);
int i;
if (ik->super() != NULL) {
do_object(ik->super());
}
objArrayOop interfaces = ik->local_interfaces();
mark_and_move_for_policy(OP_favor_startup, interfaces, _move_ro);
for(i = 0; i < interfaces->length(); i++) {
klassOop k = klassOop(interfaces->obj_at(i));
do_object(k);
}
objArrayOop methods = ik->methods();
for(i = 0; i < methods->length(); i++) {
methodOop m = methodOop(methods->obj_at(i));
mark_and_move_for_policy(OP_favor_startup, m->constMethod(), _move_ro);
mark_and_move_for_policy(OP_favor_runtime, m->constMethod()->exception_table(), _move_ro);
mark_and_move_for_policy(OP_favor_runtime, m->constMethod()->stackmap_data(), _move_ro);
}
mark_and_move_for_policy(OP_favor_startup, ik->transitive_interfaces(), _move_ro);
mark_and_move_for_policy(OP_favor_startup, ik->fields(), _move_ro);
mark_and_move_for_policy(OP_favor_runtime, ik->secondary_supers(), _move_ro);
mark_and_move_for_policy(OP_favor_runtime, ik->method_ordering(), _move_ro);
mark_and_move_for_policy(OP_favor_runtime, ik->class_annotations(), _move_ro);
mark_and_move_for_policy(OP_favor_runtime, ik->fields_annotations(), _move_ro);
mark_and_move_for_policy(OP_favor_runtime, ik->methods_annotations(), _move_ro);
mark_and_move_for_policy(OP_favor_runtime, ik->methods_parameter_annotations(), _move_ro);
mark_and_move_for_policy(OP_favor_runtime, ik->methods_default_annotations(), _move_ro);
mark_and_move_for_policy(OP_favor_runtime, ik->inner_classes(), _move_ro);
mark_and_move_for_policy(OP_favor_runtime, ik->secondary_supers(), _move_ro);
}
}
};
class MarkAndMoveOrderedReadWrite: public ObjectClosure {
private:
MoveMarkedObjects *_move_rw;
public:
MarkAndMoveOrderedReadWrite(MoveMarkedObjects *move_rw) : _move_rw(move_rw) {}
void do_object(oop obj) {
if (obj->is_klass() && obj->blueprint()->oop_is_instanceKlass()) {
instanceKlass* ik = instanceKlass::cast((klassOop)obj);
int i;
mark_and_move_for_policy(OP_favor_startup, ik->as_klassOop(), _move_rw);
if (ik->super() != NULL) {
do_object(ik->super());
}
objArrayOop interfaces = ik->local_interfaces();
for(i = 0; i < interfaces->length(); i++) {
klassOop k = klassOop(interfaces->obj_at(i));
mark_and_move_for_policy(OP_favor_startup, k, _move_rw);
do_object(k);
}
objArrayOop methods = ik->methods();
mark_and_move_for_policy(OP_favor_startup, methods, _move_rw);
for(i = 0; i < methods->length(); i++) {
methodOop m = methodOop(methods->obj_at(i));
mark_and_move_for_policy(OP_favor_startup, m, _move_rw);
mark_and_move_for_policy(OP_favor_startup, ik->constants(), _move_rw); // idempotent
mark_and_move_for_policy(OP_balanced, ik->constants()->cache(), _move_rw); // idempotent
mark_and_move_for_policy(OP_balanced, ik->constants()->tags(), _move_rw); // idempotent
}
mark_and_move_for_policy(OP_favor_startup, ik->as_klassOop()->klass(), _move_rw);
mark_and_move_for_policy(OP_favor_startup, ik->constants()->klass(), _move_rw);
// Although Java mirrors are marked in MarkReadWriteObjects,
// apparently they were never moved into shared spaces since
// MoveMarkedObjects skips marked instance oops. This may
// be a bug in the original implementation or simply the vestige
// of an abandoned experiment. Nevertheless we leave a hint
// here in case this capability is ever correctly implemented.
//
// mark_and_move_for_policy(OP_favor_runtime, ik->java_mirror(), _move_rw);
}
}
};
// Adjust references in oops to refer to shared spaces.
class ResolveForwardingClosure: public OopClosure {
public:
void do_oop(oop* p) {
oop obj = *p;
if (!obj->is_shared()) {
if (obj != NULL) {
oop f = obj->forwardee();
guarantee(f->is_shared(), "Oop doesn't refer to shared space.");
*p = f;
}
}
}
void do_oop(narrowOop* pobj) { ShouldNotReachHere(); }
};
// The methods array must be reordered by Symbol* address.
// (See classFileParser.cpp where methods in a class are originally
// sorted). The addresses of symbols have been changed as a result
// of moving to the shared space.
class SortMethodsClosure: public ObjectClosure {
public:
void do_object(oop obj) {
if (obj->blueprint()->oop_is_instanceKlass()) {
instanceKlass* ik = instanceKlass::cast((klassOop)obj);
methodOopDesc::sort_methods(ik->methods(),
ik->methods_annotations(),
ik->methods_parameter_annotations(),
ik->methods_default_annotations(),
true /* idempotent, slow */);
}
}
};
// Itable indices are calculated based on methods array order
// (see klassItable::compute_itable_index()). Must reinitialize
// after ALL methods of ALL classes have been reordered.
// We assume that since checkconstraints is false, this method
// cannot throw an exception. An exception here would be
// problematic since this is the VMThread, not a JavaThread.
class ReinitializeItables: public ObjectClosure {
private:
Thread* _thread;
public:
ReinitializeItables(Thread* thread) : _thread(thread) {}
void do_object(oop obj) {
if (obj->blueprint()->oop_is_instanceKlass()) {
instanceKlass* ik = instanceKlass::cast((klassOop)obj);
ik->itable()->initialize_itable(false, _thread);
}
}
};
// Adjust references in oops to refer to shared spaces.
class PatchOopsClosure: public ObjectClosure {
private:
Thread* _thread;
ResolveForwardingClosure resolve;
public:
PatchOopsClosure(Thread* thread) : _thread(thread) {}
void do_object(oop obj) {
obj->oop_iterate_header(&resolve);
obj->oop_iterate(&resolve);
assert(obj->klass()->is_shared(), "Klass not pointing into shared space.");
// If the object is a Java object or class which might (in the
// future) contain a reference to a young gen object, add it to the
// list.
if (obj->is_klass() || obj->is_instance()) {
if (obj->is_klass() ||
obj->is_a(SystemDictionary::Class_klass()) ||
obj->is_a(SystemDictionary::Throwable_klass())) {
// Do nothing
}
else if (obj->is_a(SystemDictionary::String_klass())) {
// immutable objects.
} else {
// someone added an object we hadn't accounted for.
ShouldNotReachHere();
}
}
}
};
// Empty the young and old generations.
class ClearSpaceClosure : public SpaceClosure {
public:
void do_space(Space* s) {
s->clear(SpaceDecorator::Mangle);
}
};
// Closure for serializing initialization data out to a data area to be
// written to the shared file.
class WriteClosure : public SerializeOopClosure {
private:
oop* top;
char* end;
inline void check_space() {
if ((char*)top + sizeof(oop) > end) {
report_out_of_shared_space(SharedMiscData);
}
}
public:
WriteClosure(char* md_top, char* md_end) {
top = (oop*)md_top;
end = md_end;
}
char* get_top() { return (char*)top; }
void do_oop(oop* p) {
check_space();
oop obj = *p;
assert(obj->is_oop_or_null(), "invalid oop");
assert(obj == NULL || obj->is_shared(),
"Oop in shared space not pointing into shared space.");
*top = obj;
++top;
}
void do_oop(narrowOop* pobj) { ShouldNotReachHere(); }
void do_int(int* p) {
check_space();
*top = (oop)(intptr_t)*p;
++top;
}
void do_size_t(size_t* p) {
check_space();
*top = (oop)(intptr_t)*p;
++top;
}
void do_ptr(void** p) {
check_space();
*top = (oop)*p;
++top;
}
void do_ptr(HeapWord** p) { do_ptr((void **) p); }
void do_tag(int tag) {
check_space();
*top = (oop)(intptr_t)tag;
++top;
}
void do_region(u_char* start, size_t size) {
if ((char*)top + size > end) {
report_out_of_shared_space(SharedMiscData);
}
assert((intptr_t)start % sizeof(oop) == 0, "bad alignment");
assert(size % sizeof(oop) == 0, "bad size");
do_tag((int)size);
while (size > 0) {
*top = *(oop*)start;
++top;
start += sizeof(oop);
size -= sizeof(oop);
}
}
bool reading() const { return false; }
};
class ResolveConstantPoolsClosure : public ObjectClosure {
private:
TRAPS;
public:
ResolveConstantPoolsClosure(Thread *t) {
__the_thread__ = t;
}
void do_object(oop obj) {
if (obj->is_constantPool()) {
constantPoolOop cpool = (constantPoolOop)obj;
int unresolved = cpool->pre_resolve_shared_klasses(THREAD);
}
}
};
// Print a summary of the contents of the read/write spaces to help
// identify objects which might be able to be made read-only. At this
// point, the objects have been written, and we can trash them as
// needed.
static void print_contents() {
if (PrintSharedSpaces) {
GenCollectedHeap* gch = GenCollectedHeap::heap();
CompactingPermGenGen* gen = (CompactingPermGenGen*)gch->perm_gen();
// High level summary of the read-only space:
ClassifyObjectClosure coc;
tty->cr(); tty->print_cr("ReadOnly space:");
gen->ro_space()->object_iterate(&coc);
coc.print();
// High level summary of the read-write space:
coc.reset();
tty->cr(); tty->print_cr("ReadWrite space:");
gen->rw_space()->object_iterate(&coc);
coc.print();
// Reset counters
ClearAllocCountClosure cacc;
gen->ro_space()->object_iterate(&cacc);
gen->rw_space()->object_iterate(&cacc);
coc.reset();
// Lower level summary of the read-only space:
gen->ro_space()->object_iterate(&coc);
tty->cr(); tty->print_cr("ReadOnly space:");
ClassifyInstanceKlassClosure cikc;
gen->rw_space()->object_iterate(&cikc);
cikc.print();
// Reset counters
gen->ro_space()->object_iterate(&cacc);
gen->rw_space()->object_iterate(&cacc);
coc.reset();
// Lower level summary of the read-write space:
gen->rw_space()->object_iterate(&coc);
cikc.reset();
tty->cr(); tty->print_cr("ReadWrite space:");
gen->rw_space()->object_iterate(&cikc);
cikc.print();
}
}
// Patch C++ vtable pointer in klass oops.
// Klass objects contain references to c++ vtables in the JVM library.
// Fix them to point to our constructed vtables. However, don't iterate
// across the space while doing this, as that causes the vtables to be
// patched, undoing our useful work. Instead, iterate to make a list,
// then use the list to do the fixing.
//
// Our constructed vtables:
// Dump time:
// 1. init_self_patching_vtbl_list: table of pointers to current virtual method addrs
// 2. generate_vtable_methods: create jump table, appended to above vtbl_list
// 3. PatchKlassVtables: for Klass list, patch the vtable entry to point to jump table
// rather than to current vtbl
// Table layout: NOTE FIXED SIZE
// 1. vtbl pointers
// 2. #Klass X #virtual methods per Klass
// 1 entry for each, in the order:
// Klass1:method1 entry, Klass1:method2 entry, ... Klass1:method<num_virtuals> entry
// Klass2:method1 entry, Klass2:method2 entry, ... Klass2:method<num_virtuals> entry
// ...
// Klass<vtbl_list_size>:method1 entry, Klass<vtbl_list_size>:method2 entry,
// ... Klass<vtbl_list_size>:method<num_virtuals> entry
// Sample entry: (Sparc):
// save(sp, -256, sp)
// ba,pt common_code
// mov XXX, %L0 %L0 gets: Klass index <<8 + method index (note: max method index 255)
//
// Restore time:
// 1. initialize_oops: reserve space for table
// 2. init_self_patching_vtbl_list: update pointers to NEW virtual method addrs in text
//
// Execution time:
// First virtual method call for any object of these Klass types:
// 1. object->klass->klass_part
// 2. vtable entry for that klass_part points to the jump table entries
// 3. branches to common_code with %O0/klass_part, %L0: Klass index <<8 + method index
// 4. common_code:
// Get address of new vtbl pointer for this Klass from updated table
// Update new vtbl pointer in the Klass: future virtual calls go direct
// Jump to method, using new vtbl pointer and method index
class PatchKlassVtables: public ObjectClosure {
private:
GrowableArray<klassOop>* _klass_objects;
public:
PatchKlassVtables() {
_klass_objects = new GrowableArray<klassOop>();
}
void do_object(oop obj) {
if (obj->is_klass()) {
_klass_objects->append(klassOop(obj));
}
}
void patch(void** vtbl_list, void* new_vtable_start) {
int n = _klass_objects->length();
for (int i = 0; i < n; i++) {
klassOop obj = (klassOop)_klass_objects->at(i);
Klass* k = obj->klass_part();
*(void**)k = CompactingPermGenGen::find_matching_vtbl_ptr(
vtbl_list, new_vtable_start, k);
}
}
};
// Walk through all symbols and patch their vtable pointers.
// Note that symbols have vtable pointers only in non-product builds
// (see allocation.hpp).
#ifndef PRODUCT
class PatchSymbolVtables: public SymbolClosure {
private:
void* _new_vtbl_ptr;
public:
PatchSymbolVtables(void** vtbl_list, void* new_vtable_start) {
Symbol s;
_new_vtbl_ptr = CompactingPermGenGen::find_matching_vtbl_ptr(
vtbl_list, new_vtable_start, &s);
}
void do_symbol(Symbol** p) {
Symbol* sym = load_symbol(p);
*(void**)sym = _new_vtbl_ptr;
}
};
#endif
// Populate the shared space.
class VM_PopulateDumpSharedSpace: public VM_Operation {
private:
GrowableArray<oop> *_class_promote_order;
OffsetTableContigSpace* _ro_space;
OffsetTableContigSpace* _rw_space;
VirtualSpace* _md_vs;
VirtualSpace* _mc_vs;
public:
VM_PopulateDumpSharedSpace(GrowableArray<oop> *class_promote_order,
OffsetTableContigSpace* ro_space,
OffsetTableContigSpace* rw_space,
VirtualSpace* md_vs, VirtualSpace* mc_vs) {
_class_promote_order = class_promote_order;
_ro_space = ro_space;
_rw_space = rw_space;
_md_vs = md_vs;
_mc_vs = mc_vs;
}
VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
void 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");
// 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");
GenCollectedHeap* gch = GenCollectedHeap::heap();
// At this point, many classes have been loaded.
// Update all the fingerprints in the shared methods.
tty->print("Calculating fingerprints ... ");
FingerprintMethodsClosure fpmc;
gch->object_iterate(&fpmc);
tty->print_cr("done. ");
// Remove all references outside the heap.
tty->print("Removing unshareable information ... ");
RemoveUnshareableInfoClosure ruic;
gch->object_iterate(&ruic);
tty->print_cr("done. ");
// Move the objects in three passes.
MarkObjectsOopClosure mark_all;
MarkCommonReadOnly mark_common_ro;
MarkStringValues mark_string_values;
MarkReadWriteObjects mark_rw;
MarkStringObjects mark_strings;
MoveMarkedObjects move_ro(_ro_space, true);
MoveMarkedObjects move_rw(_rw_space, false);
// The SharedOptimizeColdStart VM option governs the new layout
// algorithm for promoting classes into the shared archive.
// The general idea is to minimize cold start time by laying
// out the objects in the order they are accessed at startup time.
// By doing this we are trying to eliminate out-of-order accesses
// in the shared archive. This benefits cold startup time by making
// disk reads as sequential as possible during class loading and
// bootstrapping activities. There may also be a small secondary
// effect of better "packing" of more commonly used data on a smaller
// number of pages, although no direct benefit has been measured from
// this effect.
//
// At the class level of granularity, the promotion order is dictated
// by the classlist file whose generation is discussed elsewhere.
//
// At smaller granularity, optimal ordering was determined by an
// offline analysis of object access order in the shared archive.
// The dbx watchpoint facility, combined with SA post-processing,
// was used to observe common access patterns primarily during
// classloading. This information was used to craft the promotion
// order seen in the following closures.
//
// The observed access order is mostly governed by what happens
// in SystemDictionary::load_shared_class(). NOTE WELL - care
// should be taken when making changes to this method, because it
// may invalidate assumptions made about access order!
//
// (Ideally, there would be a better way to manage changes to
// the access order. Unfortunately a generic in-VM solution for
// dynamically observing access order and optimizing shared
// archive layout is pretty difficult. We go with the static
// analysis because the code is fairly mature at this point
// and we're betting that the access order won't change much.)
MarkAndMoveOrderedReadOnly mark_and_move_ordered_ro(&move_ro);
MarkAndMoveOrderedReadWrite mark_and_move_ordered_rw(&move_rw);
// Set up the share data and shared code segments.
char* md_top = _md_vs->low();
char* md_end = _md_vs->high();
char* mc_top = _mc_vs->low();
char* mc_end = _mc_vs->high();
// Reserve space for the list of klassOops whose vtables are used
// for patching others as needed.
void** vtbl_list = (void**)md_top;
int vtbl_list_size = CompactingPermGenGen::vtbl_list_size;
Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
md_top += vtbl_list_size * sizeof(void*);
void* vtable = md_top;
// Reserve space for a new dummy vtable for klass objects in the
// heap. Generate self-patching vtable entries.
CompactingPermGenGen::generate_vtable_methods(vtbl_list,
&vtable,
&md_top, md_end,
&mc_top, mc_end);
// Reserve space for the total size and the number of stored symbols.
md_top += sizeof(intptr_t) * 2;
MoveSymbols move_symbols(md_top, md_end);
CommonSymbolsClosure traverse_common_symbols(&move_symbols);
// Phase 1a: remove symbols with _refcount == 0
SymbolTable::unlink();
// Phase 1b: move commonly used symbols referenced by oop fields.
tty->print("Moving common symbols to metadata section at " PTR_FORMAT " ... ",
move_symbols.get_top());
gch->object_iterate(&traverse_common_symbols);
tty->print_cr("done. ");
// Phase 1c: move known names and signatures.
tty->print("Moving vmSymbols to metadata section at " PTR_FORMAT " ... ",
move_symbols.get_top());
vmSymbols::symbols_do(&move_symbols);
tty->print_cr("done. ");
// Phase 1d: move the remaining symbols by scanning the whole SymbolTable.
void* extra_symbols = move_symbols.get_top();
tty->print("Moving the remaining symbols to metadata section at " PTR_FORMAT " ... ",
move_symbols.get_top());
SymbolTable::symbols_do(&move_symbols);
tty->print_cr("done. ");
// Record the total length of all symbols at the beginning of the block.
((intptr_t*)md_top)[-2] = move_symbols.get_top() - md_top;
((intptr_t*)md_top)[-1] = move_symbols.count();
tty->print_cr("Moved %d symbols, %d bytes.",
move_symbols.count(), move_symbols.get_top() - md_top);
// Advance the pointer to the end of symbol store.
md_top = move_symbols.get_top();
// Phase 2: move commonly used read-only objects to the read-only space.
if (SharedOptimizeColdStart) {
tty->print("Moving pre-ordered read-only objects to shared space at " PTR_FORMAT " ... ",
_ro_space->top());
for (int i = 0; i < _class_promote_order->length(); i++) {
oop obj = _class_promote_order->at(i);
mark_and_move_ordered_ro.do_object(obj);
}
tty->print_cr("done. ");
}
tty->print("Moving read-only objects to shared space at " PTR_FORMAT " ... ",
_ro_space->top());
gch->object_iterate(&mark_common_ro);
gch->object_iterate(&move_ro);
tty->print_cr("done. ");
// Phase 3: move String character arrays to the read-only space.
tty->print("Moving string char arrays to shared space at " PTR_FORMAT " ... ",
_ro_space->top());
gch->object_iterate(&mark_string_values);
gch->object_iterate(&move_ro);
tty->print_cr("done. ");
// Phase 4: move read-write objects to the read-write space, except
// Strings.
if (SharedOptimizeColdStart) {
tty->print("Moving pre-ordered read-write objects to shared space at " PTR_FORMAT " ... ",
_rw_space->top());
for (int i = 0; i < _class_promote_order->length(); i++) {
oop obj = _class_promote_order->at(i);
mark_and_move_ordered_rw.do_object(obj);
}
tty->print_cr("done. ");
}
tty->print("Moving read-write objects to shared space at " PTR_FORMAT " ... ",
_rw_space->top());
Universe::oops_do(&mark_all, true);
SystemDictionary::oops_do(&mark_all);
oop tmp = Universe::arithmetic_exception_instance();
mark_object(java_lang_Throwable::message(tmp));
gch->object_iterate(&mark_rw);
gch->object_iterate(&move_rw);
tty->print_cr("done. ");
// Phase 5: move String objects to the read-write space.
tty->print("Moving String objects to shared space at " PTR_FORMAT " ... ",
_rw_space->top());
StringTable::oops_do(&mark_all);
gch->object_iterate(&mark_strings);
gch->object_iterate(&move_rw);
tty->print_cr("done. ");
tty->print_cr("Read-write space ends at " PTR_FORMAT ", %d bytes.",
_rw_space->top(), _rw_space->used());
#ifdef DEBUG
// Check: scan for objects which were not moved.
CheckRemainingObjects check_objects;
gch->object_iterate(&check_objects);
check_objects.status();
#endif
// Resolve forwarding in objects and saved C++ structures
tty->print("Updating references to shared objects ... ");
ResolveForwardingClosure resolve;
Universe::oops_do(&resolve);
SystemDictionary::oops_do(&resolve);
StringTable::oops_do(&resolve);
// Fix (forward) all of the references in these shared objects (which
// are required to point ONLY to objects in the shared spaces).
// Also, create a list of all objects which might later contain a
// reference to a younger generation object.
CompactingPermGenGen* gen = (CompactingPermGenGen*)gch->perm_gen();
PatchOopsClosure patch(THREAD);
gen->ro_space()->object_iterate(&patch);
gen->rw_space()->object_iterate(&patch);
// Previously method sorting was done concurrently with forwarding
// pointer resolution in the shared spaces. This imposed an ordering
// restriction in that methods were required to be promoted/patched
// before their holder classes. (Because constant pool pointers in
// methodKlasses are required to be resolved before their holder class
// is visited for sorting, otherwise methods are sorted by incorrect,
// pre-forwarding addresses.)
//
// Now, we reorder methods as a separate step after ALL forwarding
// pointer resolution, so that methods can be promoted in any order
// with respect to their holder classes.
SortMethodsClosure sort;
gen->ro_space()->object_iterate(&sort);
gen->rw_space()->object_iterate(&sort);
ReinitializeItables reinit_itables(THREAD);
gen->ro_space()->object_iterate(&reinit_itables);
gen->rw_space()->object_iterate(&reinit_itables);
tty->print_cr("done. ");
tty->cr();
// Reorder the system dictionary. (Moving the symbols opps affects
// how the hash table indices are calculated.)
SystemDictionary::reorder_dictionary();
// Empty the non-shared heap (because most of the objects were
// copied out, and the remainder cannot be considered valid oops).
ClearSpaceClosure csc;
for (int i = 0; i < gch->n_gens(); ++i) {
gch->get_gen(i)->space_iterate(&csc);
}
csc.do_space(gen->the_space());
NOT_PRODUCT(SystemDictionary::verify();)
// Copy the String table, the symbol table, and the system
// dictionary to the shared space in usable form. Copy the hastable
// buckets first [read-write], then copy the linked lists of entries
// [read-only].
SymbolTable::reverse(extra_symbols);
NOT_PRODUCT(SymbolTable::verify());
SymbolTable::copy_buckets(&md_top, md_end);
StringTable::reverse();
NOT_PRODUCT(StringTable::verify());
StringTable::copy_buckets(&md_top, md_end);
SystemDictionary::reverse();
SystemDictionary::copy_buckets(&md_top, md_end);
ClassLoader::verify();
ClassLoader::copy_package_info_buckets(&md_top, md_end);
ClassLoader::verify();
SymbolTable::copy_table(&md_top, md_end);
StringTable::copy_table(&md_top, md_end);
SystemDictionary::copy_table(&md_top, md_end);
ClassLoader::verify();
ClassLoader::copy_package_info_table(&md_top, md_end);
ClassLoader::verify();
// Print debug data.
if (PrintSharedSpaces) {
const char* fmt = "%s space: " PTR_FORMAT " out of " PTR_FORMAT " bytes allocated at " PTR_FORMAT ".";
tty->print_cr(fmt, "ro", _ro_space->used(), _ro_space->capacity(),
_ro_space->bottom());
tty->print_cr(fmt, "rw", _rw_space->used(), _rw_space->capacity(),
_rw_space->bottom());
}
// Write the oop data to the output array.
WriteClosure wc(md_top, md_end);
CompactingPermGenGen::serialize_oops(&wc);
md_top = wc.get_top();
// Update the vtable pointers in all of the Klass objects in the
// heap. They should point to newly generated vtable.
PatchKlassVtables pkvt;
_rw_space->object_iterate(&pkvt);
pkvt.patch(vtbl_list, vtable);
#ifndef PRODUCT
// Update the vtable pointers in all symbols,
// but only in non-product builds where symbols DO have virtual methods.
PatchSymbolVtables psvt(vtbl_list, vtable);
SymbolTable::symbols_do(&psvt);
#endif
char* saved_vtbl = (char*)malloc(vtbl_list_size * sizeof(void*));
memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*));
memset(vtbl_list, 0, vtbl_list_size * sizeof(void*));
// Create and write the archive file that maps the shared spaces.
FileMapInfo* mapinfo = new FileMapInfo();
mapinfo->populate_header(gch->gen_policy()->max_alignment());
// Pass 1 - update file offsets in header.
mapinfo->write_header();
mapinfo->write_space(CompactingPermGenGen::ro, _ro_space, true);
_ro_space->set_saved_mark();
mapinfo->write_space(CompactingPermGenGen::rw, _rw_space, false);
_rw_space->set_saved_mark();
mapinfo->write_region(CompactingPermGenGen::md, _md_vs->low(),
pointer_delta(md_top, _md_vs->low(), sizeof(char)),
SharedMiscDataSize,
false, false);
mapinfo->write_region(CompactingPermGenGen::mc, _mc_vs->low(),
pointer_delta(mc_top, _mc_vs->low(), sizeof(char)),
SharedMiscCodeSize,
true, true);
// Pass 2 - write data.
mapinfo->open_for_write();
mapinfo->write_header();
mapinfo->write_space(CompactingPermGenGen::ro, _ro_space, true);
mapinfo->write_space(CompactingPermGenGen::rw, _rw_space, false);
mapinfo->write_region(CompactingPermGenGen::md, _md_vs->low(),
pointer_delta(md_top, _md_vs->low(), sizeof(char)),
SharedMiscDataSize,
false, false);
mapinfo->write_region(CompactingPermGenGen::mc, _mc_vs->low(),
pointer_delta(mc_top, _mc_vs->low(), sizeof(char)),
SharedMiscCodeSize,
true, true);
mapinfo->close();
// Summarize heap.
memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*));
print_contents();
}
}; // class VM_PopulateDumpSharedSpace
// Populate the shared spaces and dump to a file.
jint CompactingPermGenGen::dump_shared(GrowableArray<oop>* class_promote_order, TRAPS) {
GenCollectedHeap* gch = GenCollectedHeap::heap();
// Calculate hash values for all of the (interned) strings to avoid
// writes to shared pages in the future.
tty->print("Calculating hash values for String objects .. ");
StringHashCodeClosure shcc(THREAD);
StringTable::oops_do(&shcc);
tty->print_cr("done. ");
CompactingPermGenGen* gen = (CompactingPermGenGen*)gch->perm_gen();
VM_PopulateDumpSharedSpace op(class_promote_order,
gen->ro_space(), gen->rw_space(),
gen->md_space(), gen->mc_space());
VMThread::execute(&op);
return JNI_OK;
}
void* CompactingPermGenGen::find_matching_vtbl_ptr(void** vtbl_list,
void* new_vtable_start,
void* obj) {
void* old_vtbl_ptr = *(void**)obj;
for (int i = 0; i < vtbl_list_size; i++) {
if (vtbl_list[i] == old_vtbl_ptr) {
return (void**)new_vtable_start + i * num_virtuals;
}
}
ShouldNotReachHere();
return NULL;
}
class LinkClassesClosure : public ObjectClosure {
private:
Thread* THREAD;
public:
LinkClassesClosure(Thread* thread) : THREAD(thread) {}
void do_object(oop obj) {
if (obj->is_klass()) {
Klass* k = Klass::cast((klassOop) obj);
if (k->oop_is_instance()) {
instanceKlass* ik = (instanceKlass*) k;
// Link the class to cause the bytecodes to be rewritten and the
// cpcache to be created.
if (ik->get_init_state() < instanceKlass::linked) {
ik->link_class(THREAD);
guarantee(!HAS_PENDING_EXCEPTION, "exception in class rewriting");
}
// Create String objects from string initializer symbols.
ik->constants()->resolve_string_constants(THREAD);
guarantee(!HAS_PENDING_EXCEPTION, "exception resolving string constants");
}
}
}
};
// Support for a simple checksum of the contents of the class list
// file to prevent trivial tampering. The algorithm matches that in
// the MakeClassList program used by the J2SE build process.
#define JSUM_SEED ((jlong)CONST64(0xcafebabebabecafe))
static jlong
jsum(jlong start, const char *buf, const int len)
{
jlong h = start;
char *p = (char *)buf, *e = p + len;
while (p < e) {
char c = *p++;
if (c <= ' ') {
/* Skip spaces and control characters */
continue;
}
h = 31 * h + c;
}
return h;
}
// Preload classes from a list, populate the shared spaces and dump to a
// file.
void GenCollectedHeap::preload_and_dump(TRAPS) {
TraceTime timer("Dump Shared Spaces", TraceStartupTime);
ResourceMark rm;
// Preload classes to be shared.
// Should use some os:: method rather than fopen() here. aB.
// 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)
char class_list_path[JVM_MAXPATHLEN];
os::jvm_path(class_list_path, sizeof(class_list_path));
for (int i = 0; i < 3; i++) {
char *end = strrchr(class_list_path, *os::file_separator());
if (end != NULL) *end = '\0';
}
int class_list_path_len = (int)strlen(class_list_path);
if (class_list_path_len >= 3) {
if (strcmp(class_list_path + class_list_path_len - 3, "lib") != 0) {
strcat(class_list_path, os::file_separator());
strcat(class_list_path, "lib");
}
}
strcat(class_list_path, os::file_separator());
strcat(class_list_path, "classlist");
FILE* file = fopen(class_list_path, "r");
if (file != NULL) {
jlong computed_jsum = JSUM_SEED;
jlong file_jsum = 0;
char class_name[256];
int class_count = 0;
GenCollectedHeap* gch = GenCollectedHeap::heap();
gch->_preloading_shared_classes = true;
GrowableArray<oop>* class_promote_order = new GrowableArray<oop>();
// Preload (and intern) strings which will be used later.
StringTable::intern("main", THREAD);
StringTable::intern("([Ljava/lang/String;)V", THREAD);
StringTable::intern("Ljava/lang/Class;", THREAD);
StringTable::intern("I", THREAD); // Needed for StringBuffer persistence?
StringTable::intern("Z", THREAD); // Needed for StringBuffer persistence?
// sun.io.Converters
static const char obj_array_sig[] = "[[Ljava/lang/Object;";
SymbolTable::lookup(obj_array_sig, (int)strlen(obj_array_sig), THREAD);
// java.util.HashMap
static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;";
SymbolTable::lookup(map_entry_array_sig, (int)strlen(map_entry_array_sig),
THREAD);
tty->print("Loading classes to share ... ");
while ((fgets(class_name, sizeof class_name, file)) != NULL) {
if (*class_name == '#') {
jint fsh, fsl;
if (sscanf(class_name, "# %8x%8x\n", &fsh, &fsl) == 2) {
file_jsum = ((jlong)(fsh) << 32) | (fsl & 0xffffffff);
}
continue;
}
// Remove trailing newline
size_t name_len = strlen(class_name);
class_name[name_len-1] = '\0';
computed_jsum = jsum(computed_jsum, class_name, (const int)name_len - 1);
// Got a class name - load it.
TempNewSymbol class_name_symbol = SymbolTable::new_symbol(class_name, THREAD);
guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol.");
klassOop klass = SystemDictionary::resolve_or_null(class_name_symbol,
THREAD);
guarantee(!HAS_PENDING_EXCEPTION, "Exception resolving a class.");
if (klass != NULL) {
if (PrintSharedSpaces) {
tty->print_cr("Shared spaces preloaded: %s", class_name);
}
instanceKlass* ik = instanceKlass::cast(klass);
// Should be class load order as per -XX:+TraceClassLoadingPreorder
class_promote_order->append(ik->as_klassOop());
// 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,
// cpCache, Sting constants) are located together.
if (ik->get_init_state() < instanceKlass::linked) {
ik->link_class(THREAD);
guarantee(!(HAS_PENDING_EXCEPTION), "exception in class rewriting");
}
// Create String objects from string initializer symbols.
ik->constants()->resolve_string_constants(THREAD);
class_count++;
} else {
if (PrintSharedSpaces) {
tty->cr();
tty->print_cr(" Preload failed: %s", class_name);
}
}
file_jsum = 0; // Checksum must be on last line of file
}
if (computed_jsum != file_jsum) {
tty->cr();
tty->print_cr("Preload failed: checksum of class list was incorrect.");
exit(1);
}
tty->print_cr("done. ");
if (PrintSharedSpaces) {
tty->print_cr("Shared spaces: preloaded %d classes", class_count);
}
// Rewrite and unlink classes.
tty->print("Rewriting and unlinking classes ... ");
// Make heap parsable
ensure_parsability(false); // arg is actually don't care
// Link any classes which got missed. (It's not quite clear why
// they got missed.) This iteration would be unsafe if we weren't
// single-threaded at this point; however we can't do it on the VM
// thread because it requires object allocation.
LinkClassesClosure lcc(Thread::current());
object_iterate(&lcc);
ensure_parsability(false); // arg is actually don't care
tty->print_cr("done. ");
// Create and dump the shared spaces.
jint err = CompactingPermGenGen::dump_shared(class_promote_order, THREAD);
if (err != JNI_OK) {
fatal("Dumping shared spaces failed.");
}
} else {
char errmsg[JVM_MAXPATHLEN];
os::lasterror(errmsg, JVM_MAXPATHLEN);
tty->print_cr("Loading classlist failed: %s", errmsg);
exit(1);
}
// Since various initialization steps have been undone by this process,
// it is not reasonable to continue running a java process.
exit(0);
}