1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/utilities/bitMap.inline.hpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,105 @@
1.4 +/*
1.5 + * Copyright 2005-2006 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +inline bool BitMap::par_set_bit(idx_t bit) {
1.29 + verify_index(bit);
1.30 + volatile idx_t* const addr = word_addr(bit);
1.31 + const idx_t mask = bit_mask(bit);
1.32 + idx_t old_val = *addr;
1.33 +
1.34 + do {
1.35 + const idx_t new_val = old_val | mask;
1.36 + if (new_val == old_val) {
1.37 + return false; // Someone else beat us to it.
1.38 + }
1.39 + const idx_t cur_val = (idx_t) Atomic::cmpxchg_ptr((void*) new_val,
1.40 + (volatile void*) addr,
1.41 + (void*) old_val);
1.42 + if (cur_val == old_val) {
1.43 + return true; // Success.
1.44 + }
1.45 + old_val = cur_val; // The value changed, try again.
1.46 + } while (true);
1.47 +}
1.48 +
1.49 +inline bool BitMap::par_clear_bit(idx_t bit) {
1.50 + verify_index(bit);
1.51 + volatile idx_t* const addr = word_addr(bit);
1.52 + const idx_t mask = ~bit_mask(bit);
1.53 + idx_t old_val = *addr;
1.54 +
1.55 + do {
1.56 + const idx_t new_val = old_val & mask;
1.57 + if (new_val == old_val) {
1.58 + return false; // Someone else beat us to it.
1.59 + }
1.60 + const idx_t cur_val = (idx_t) Atomic::cmpxchg_ptr((void*) new_val,
1.61 + (volatile void*) addr,
1.62 + (void*) old_val);
1.63 + if (cur_val == old_val) {
1.64 + return true; // Success.
1.65 + }
1.66 + old_val = cur_val; // The value changed, try again.
1.67 + } while (true);
1.68 +}
1.69 +
1.70 +inline BitMap::idx_t
1.71 +BitMap::find_next_one_bit(idx_t beg_bit, idx_t end_bit) const
1.72 +{
1.73 + verify_range(beg_bit, end_bit);
1.74 + assert(bit_in_word(end_bit) == 0, "end_bit not word-aligned");
1.75 +
1.76 + if (beg_bit == end_bit) {
1.77 + return beg_bit;
1.78 + }
1.79 +
1.80 + idx_t index = word_index(beg_bit);
1.81 + idx_t r_index = word_index(end_bit);
1.82 + idx_t res_bit = beg_bit;
1.83 +
1.84 + // check bits including and to the _left_ of offset's position
1.85 + idx_t res = map(index) >> bit_in_word(res_bit);
1.86 + if (res != (uintptr_t) NoBits) {
1.87 + // find the position of the 1-bit
1.88 + for (; !(res & 1); res_bit++) {
1.89 + res = res >> 1;
1.90 + }
1.91 + assert(res_bit >= beg_bit && res_bit < end_bit, "just checking");
1.92 + return res_bit;
1.93 + }
1.94 + // skip over all word length 0-bit runs
1.95 + for (index++; index < r_index; index++) {
1.96 + res = map(index);
1.97 + if (res != (uintptr_t) NoBits) {
1.98 + // found a 1, return the offset
1.99 + for (res_bit = bit_index(index); !(res & 1); res_bit++) {
1.100 + res = res >> 1;
1.101 + }
1.102 + assert(res & 1, "tautology; see loop condition");
1.103 + assert(res_bit >= beg_bit && res_bit < end_bit, "just checking");
1.104 + return res_bit;
1.105 + }
1.106 + }
1.107 + return end_bit;
1.108 +}
