6964458: Reimplement class meta-data storage to use native memory
Summary: Remove PermGen, allocate meta-data in metaspace linked to class loaders, rewrite GC walking, rewrite and rename metadata to be C++ classes
Reviewed-by: jmasa, stefank, never, coleenp, kvn, brutisso, mgerdin, dholmes, jrose, twisti, roland
Contributed-by: jmasa <jon.masamitsu@oracle.com>, stefank <stefan.karlsson@oracle.com>, mgerdin <mikael.gerdin@oracle.com>, never <tom.rodriguez@oracle.com>
/*
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* 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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#ifndef SHARE_VM_OOPS_OOP_PCGC_INLINE_HPP
#define SHARE_VM_OOPS_OOP_PCGC_INLINE_HPP
#ifndef SERIALGC
#include "gc_implementation/parNew/parNewGeneration.hpp"
#include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
#include "gc_implementation/parallelScavenge/psCompactionManager.hpp"
#include "gc_implementation/parallelScavenge/psParallelCompact.hpp"
#include "gc_implementation/parallelScavenge/psScavenge.hpp"
#include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
#endif
inline void oopDesc::update_contents(ParCompactionManager* cm) {
// The klass field must be updated before anything else
// can be done.
DEBUG_ONLY(Klass* original_klass = klass());
Klass* new_klass = klass();
if (!new_klass->oop_is_typeArray()) {
// It might contain oops beyond the header, so take the virtual call.
new_klass->oop_update_pointers(cm, this);
}
// Else skip it. The typeArrayKlass in the header never needs scavenging.
}
inline void oopDesc::follow_contents(ParCompactionManager* cm) {
assert (PSParallelCompact::mark_bitmap()->is_marked(this),
"should be marked");
klass()->oop_follow_contents(cm, this);
}
// Used by parallel old GC.
inline oop oopDesc::forward_to_atomic(oop p) {
assert(ParNewGeneration::is_legal_forward_ptr(p),
"illegal forwarding pointer value.");
markOop oldMark = mark();
markOop forwardPtrMark = markOopDesc::encode_pointer_as_mark(p);
markOop curMark;
assert(forwardPtrMark->decode_pointer() == p, "encoding must be reversable");
assert(sizeof(markOop) == sizeof(intptr_t), "CAS below requires this.");
while (!oldMark->is_marked()) {
curMark = (markOop)Atomic::cmpxchg_ptr(forwardPtrMark, &_mark, oldMark);
assert(is_forwarded(), "object should have been forwarded");
if (curMark == oldMark) {
return NULL;
}
// If the CAS was unsuccessful then curMark->is_marked()
// should return true as another thread has CAS'd in another
// forwarding pointer.
oldMark = curMark;
}
return forwardee();
}
inline void oopDesc::update_header(ParCompactionManager* cm) {
PSParallelCompact::adjust_klass(cm, klass());
}
#endif // SHARE_VM_OOPS_OOP_PCGC_INLINE_HPP