1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/parallelScavenge/objectStartArray.cpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,137 @@
1.4 +/*
1.5 + * Copyright 2001-2005 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 +# include "incls/_precompiled.incl"
1.29 +# include "incls/_objectStartArray.cpp.incl"
1.30 +
1.31 +void ObjectStartArray::initialize(MemRegion reserved_region) {
1.32 + // We're based on the assumption that we use the same
1.33 + // size blocks as the card table.
1.34 + assert((int)block_size == (int)CardTableModRefBS::card_size, "Sanity");
1.35 + assert((int)block_size <= 512, "block_size must be less than or equal to 512");
1.36 +
1.37 + // Calculate how much space must be reserved
1.38 + _reserved_region = reserved_region;
1.39 +
1.40 + size_t bytes_to_reserve = reserved_region.word_size() / block_size_in_words;
1.41 + assert(bytes_to_reserve > 0, "Sanity");
1.42 +
1.43 + bytes_to_reserve =
1.44 + align_size_up(bytes_to_reserve, os::vm_allocation_granularity());
1.45 +
1.46 + // Do not use large-pages for the backing store. The one large page region
1.47 + // will be used for the heap proper.
1.48 + ReservedSpace backing_store(bytes_to_reserve);
1.49 + if (!backing_store.is_reserved()) {
1.50 + vm_exit_during_initialization("Could not reserve space for ObjectStartArray");
1.51 + }
1.52 +
1.53 + // We do not commit any memory initially
1.54 + if (!_virtual_space.initialize(backing_store, 0)) {
1.55 + vm_exit_during_initialization("Could not commit space for ObjectStartArray");
1.56 + }
1.57 +
1.58 + _raw_base = (jbyte*)_virtual_space.low_boundary();
1.59 + if (_raw_base == NULL) {
1.60 + vm_exit_during_initialization("Could not get raw_base address");
1.61 + }
1.62 +
1.63 + _offset_base = _raw_base - (size_t(reserved_region.start()) >> block_shift);
1.64 +
1.65 + _covered_region.set_start(reserved_region.start());
1.66 + _covered_region.set_word_size(0);
1.67 +
1.68 + _blocks_region.set_start((HeapWord*)_raw_base);
1.69 + _blocks_region.set_word_size(0);
1.70 +}
1.71 +
1.72 +void ObjectStartArray::set_covered_region(MemRegion mr) {
1.73 + assert(_reserved_region.contains(mr), "MemRegion outside of reserved space");
1.74 + assert(_reserved_region.start() == mr.start(), "Attempt to move covered region");
1.75 +
1.76 + HeapWord* low_bound = mr.start();
1.77 + HeapWord* high_bound = mr.end();
1.78 + assert((uintptr_t(low_bound) & (block_size - 1)) == 0, "heap must start at block boundary");
1.79 + assert((uintptr_t(high_bound) & (block_size - 1)) == 0, "heap must end at block boundary");
1.80 +
1.81 + size_t requested_blocks_size_in_bytes = mr.word_size() / block_size_in_words;
1.82 +
1.83 + // Only commit memory in page sized chunks
1.84 + requested_blocks_size_in_bytes =
1.85 + align_size_up(requested_blocks_size_in_bytes, os::vm_page_size());
1.86 +
1.87 + _covered_region = mr;
1.88 +
1.89 + size_t current_blocks_size_in_bytes = _blocks_region.byte_size();
1.90 +
1.91 + if (requested_blocks_size_in_bytes > current_blocks_size_in_bytes) {
1.92 + // Expand
1.93 + size_t expand_by = requested_blocks_size_in_bytes - current_blocks_size_in_bytes;
1.94 + if (!_virtual_space.expand_by(expand_by)) {
1.95 + vm_exit_out_of_memory(expand_by, "object start array expansion");
1.96 + }
1.97 + // Clear *only* the newly allocated region
1.98 + memset(_blocks_region.end(), clean_block, expand_by);
1.99 + }
1.100 +
1.101 + if (requested_blocks_size_in_bytes < current_blocks_size_in_bytes) {
1.102 + // Shrink
1.103 + size_t shrink_by = current_blocks_size_in_bytes - requested_blocks_size_in_bytes;
1.104 + _virtual_space.shrink_by(shrink_by);
1.105 + }
1.106 +
1.107 + _blocks_region.set_word_size(requested_blocks_size_in_bytes / sizeof(HeapWord));
1.108 +
1.109 + assert(requested_blocks_size_in_bytes % sizeof(HeapWord) == 0, "Block table not expanded in word sized increment");
1.110 + assert(requested_blocks_size_in_bytes == _blocks_region.byte_size(), "Sanity");
1.111 + assert(block_for_addr(low_bound) == &_raw_base[0], "Checking start of map");
1.112 + assert(block_for_addr(high_bound-1) <= &_raw_base[_blocks_region.byte_size()-1], "Checking end of map");
1.113 +}
1.114 +
1.115 +void ObjectStartArray::reset() {
1.116 + memset(_blocks_region.start(), clean_block, _blocks_region.byte_size());
1.117 +}
1.118 +
1.119 +
1.120 +bool ObjectStartArray::object_starts_in_range(HeapWord* start_addr,
1.121 + HeapWord* end_addr) const {
1.122 + assert(start_addr <= end_addr, "range is wrong");
1.123 + if (start_addr > end_addr) {
1.124 + return false;
1.125 + }
1.126 +
1.127 + jbyte* start_block = block_for_addr(start_addr);
1.128 + jbyte* end_block = block_for_addr(end_addr);
1.129 +
1.130 + for (jbyte* block = start_block; block <= end_block; block++) {
1.131 + if (*block != clean_block) {
1.132 + return true;
1.133 + }
1.134 + }
1.135 + // No object starts in this slice; verify this using
1.136 + // more traditional methods:
1.137 + assert(object_start(end_addr - 1) <= start_addr,
1.138 + "Oops an object does start in this slice?");
1.139 + return false;
1.140 +}
