| /* |
| * Copyright (c) 2015, 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. |
| */ |
| |
| #ifndef SHARE_GC_Z_ZFORWARDING_INLINE_HPP |
| #define SHARE_GC_Z_ZFORWARDING_INLINE_HPP |
| |
| #include "gc/z/zAttachedArray.inline.hpp" |
| #include "gc/z/zForwarding.hpp" |
| #include "gc/z/zGlobals.hpp" |
| #include "gc/z/zHash.inline.hpp" |
| #include "gc/z/zHeap.hpp" |
| #include "gc/z/zVirtualMemory.inline.hpp" |
| #include "runtime/atomic.hpp" |
| #include "utilities/debug.hpp" |
| |
| inline uintptr_t ZForwarding::start() const { |
| return _virtual.start(); |
| } |
| |
| inline size_t ZForwarding::size() const { |
| return _virtual.size(); |
| } |
| |
| inline size_t ZForwarding::object_alignment_shift() const { |
| return _object_alignment_shift; |
| } |
| |
| inline ZPage* ZForwarding::page() const { |
| return _page; |
| } |
| |
| inline bool ZForwarding::is_pinned() const { |
| return Atomic::load(&_pinned); |
| } |
| |
| inline void ZForwarding::set_pinned() { |
| Atomic::store(true, &_pinned); |
| } |
| |
| inline bool ZForwarding::inc_refcount() { |
| uint32_t refcount = Atomic::load(&_refcount); |
| |
| while (refcount > 0) { |
| const uint32_t old_refcount = refcount; |
| const uint32_t new_refcount = old_refcount + 1; |
| const uint32_t prev_refcount = Atomic::cmpxchg(new_refcount, &_refcount, old_refcount); |
| if (prev_refcount == old_refcount) { |
| return true; |
| } |
| |
| refcount = prev_refcount; |
| } |
| |
| return false; |
| } |
| |
| inline bool ZForwarding::dec_refcount() { |
| assert(_refcount > 0, "Invalid state"); |
| return Atomic::sub(1u, &_refcount) == 0u; |
| } |
| |
| inline bool ZForwarding::retain_page() { |
| return inc_refcount(); |
| } |
| |
| inline void ZForwarding::release_page() { |
| if (dec_refcount()) { |
| ZHeap::heap()->free_page(_page, true /* reclaimed */); |
| _page = NULL; |
| } |
| } |
| |
| inline ZForwardingEntry* ZForwarding::entries() const { |
| return _entries(this); |
| } |
| |
| inline ZForwardingEntry ZForwarding::at(ZForwardingCursor* cursor) const { |
| return Atomic::load(entries() + *cursor); |
| } |
| |
| inline ZForwardingEntry ZForwarding::first(uintptr_t from_index, ZForwardingCursor* cursor) const { |
| const size_t mask = _entries.length() - 1; |
| const size_t hash = ZHash::uint32_to_uint32((uint32_t)from_index); |
| *cursor = hash & mask; |
| return at(cursor); |
| } |
| |
| inline ZForwardingEntry ZForwarding::next(ZForwardingCursor* cursor) const { |
| const size_t mask = _entries.length() - 1; |
| *cursor = (*cursor + 1) & mask; |
| return at(cursor); |
| } |
| |
| inline ZForwardingEntry ZForwarding::find(uintptr_t from_index) const { |
| ZForwardingCursor dummy; |
| return find(from_index, &dummy); |
| } |
| |
| inline ZForwardingEntry ZForwarding::find(uintptr_t from_index, ZForwardingCursor* cursor) const { |
| // Reading entries in the table races with the atomic CAS done for |
| // insertion into the table. This is safe because each entry is at |
| // most updated once (from zero to something else). |
| ZForwardingEntry entry = first(from_index, cursor); |
| while (entry.populated()) { |
| if (entry.from_index() == from_index) { |
| // Match found, return matching entry |
| return entry; |
| } |
| |
| entry = next(cursor); |
| } |
| |
| // Match not found, return empty entry |
| return entry; |
| } |
| |
| inline uintptr_t ZForwarding::insert(uintptr_t from_index, uintptr_t to_offset, ZForwardingCursor* cursor) { |
| const ZForwardingEntry new_entry(from_index, to_offset); |
| const ZForwardingEntry old_entry; // Empty |
| |
| for (;;) { |
| const ZForwardingEntry prev_entry = Atomic::cmpxchg(new_entry, entries() + *cursor, old_entry); |
| if (!prev_entry.populated()) { |
| // Success |
| return to_offset; |
| } |
| |
| // Find next empty or matching entry |
| ZForwardingEntry entry = at(cursor); |
| while (entry.populated()) { |
| if (entry.from_index() == from_index) { |
| // Match found, return already inserted address |
| return entry.to_offset(); |
| } |
| |
| entry = next(cursor); |
| } |
| } |
| } |
| |
| #endif // SHARE_GC_Z_ZFORWARDING_INLINE_HPP |