1 /* 2 * Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 #ifndef SHARE_GC_Z_ZBITMAP_INLINE_HPP 25 #define SHARE_GC_Z_ZBITMAP_INLINE_HPP 26 27 #include "gc/z/zBitMap.hpp" 28 #include "runtime/atomic.hpp" 29 #include "utilities/bitMap.inline.hpp" 30 #include "utilities/debug.hpp" 31 32 inline ZBitMap::ZBitMap(idx_t size_in_bits) : 33 CHeapBitMap(size_in_bits, mtGC, false /* clear */) {} 34 35 inline BitMap::bm_word_t ZBitMap::bit_mask_pair(idx_t bit) { 36 assert(bit_in_word(bit) < BitsPerWord - 1, "Invalid bit index"); 37 return (bm_word_t)3 << bit_in_word(bit); 38 } 39 40 inline bool ZBitMap::par_set_bit_pair_finalizable(idx_t bit, bool& inc_live) { 41 inc_live = par_set_bit(bit); 42 return inc_live; 43 } 44 45 inline bool ZBitMap::par_set_bit_pair_strong(idx_t bit, bool& inc_live) { 46 verify_index(bit); 47 volatile bm_word_t* const addr = word_addr(bit); 48 const bm_word_t pair_mask = bit_mask_pair(bit); 49 bm_word_t old_val = *addr; 50 51 do { 52 const bm_word_t new_val = old_val | pair_mask; 53 if (new_val == old_val) { 54 // Someone else beat us to it 55 inc_live = false; 56 return false; 57 } 58 const bm_word_t cur_val = Atomic::cmpxchg(new_val, addr, old_val); 59 if (cur_val == old_val) { 60 // Success 61 const bm_word_t marked_mask = bit_mask(bit); 62 inc_live = !(old_val & marked_mask); 63 return true; 64 } 65 66 // The value changed, retry 67 old_val = cur_val; 68 } while (true); 69 } 70 71 inline bool ZBitMap::par_set_bit_pair(idx_t bit, bool finalizable, bool& inc_live) { 72 if (finalizable) { 73 return par_set_bit_pair_finalizable(bit, inc_live); 74 } else { 75 return par_set_bit_pair_strong(bit, inc_live); 76 } 77 } 78 79 #endif // SHARE_GC_Z_ZBITMAP_INLINE_HPP