Fri, 18 Feb 2011 10:07:34 -0800
7020042: G1: Partially remove fix for 6994628
Summary: Disable reference discovery and processing during concurrent marking by disabling fix for 6994628.
Reviewed-by: tonyp, ysr
ysr@777 | 1 | /* |
tonyp@2453 | 2 | * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved. |
ysr@777 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
ysr@777 | 4 | * |
ysr@777 | 5 | * This code is free software; you can redistribute it and/or modify it |
ysr@777 | 6 | * under the terms of the GNU General Public License version 2 only, as |
ysr@777 | 7 | * published by the Free Software Foundation. |
ysr@777 | 8 | * |
ysr@777 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
ysr@777 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
ysr@777 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
ysr@777 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
ysr@777 | 13 | * accompanied this code). |
ysr@777 | 14 | * |
ysr@777 | 15 | * You should have received a copy of the GNU General Public License version |
ysr@777 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
ysr@777 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
ysr@777 | 18 | * |
trims@1907 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
trims@1907 | 20 | * or visit www.oracle.com if you need additional information or have any |
trims@1907 | 21 | * questions. |
ysr@777 | 22 | * |
ysr@777 | 23 | */ |
ysr@777 | 24 | |
stefank@2314 | 25 | #include "precompiled.hpp" |
stefank@2314 | 26 | #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" |
stefank@2314 | 27 | #include "gc_implementation/g1/heapRegionSeq.hpp" |
stefank@2314 | 28 | #include "memory/allocation.hpp" |
ysr@777 | 29 | |
ysr@777 | 30 | // Local to this file. |
ysr@777 | 31 | |
ysr@777 | 32 | static int orderRegions(HeapRegion** hr1p, HeapRegion** hr2p) { |
ysr@777 | 33 | if ((*hr1p)->end() <= (*hr2p)->bottom()) return -1; |
ysr@777 | 34 | else if ((*hr2p)->end() <= (*hr1p)->bottom()) return 1; |
ysr@777 | 35 | else if (*hr1p == *hr2p) return 0; |
ysr@777 | 36 | else { |
ysr@777 | 37 | assert(false, "We should never compare distinct overlapping regions."); |
ysr@777 | 38 | } |
ysr@777 | 39 | return 0; |
ysr@777 | 40 | } |
ysr@777 | 41 | |
iveresov@828 | 42 | HeapRegionSeq::HeapRegionSeq(const size_t max_size) : |
ysr@777 | 43 | _alloc_search_start(0), |
ysr@777 | 44 | // The line below is the worst bit of C++ hackery I've ever written |
ysr@777 | 45 | // (Detlefs, 11/23). You should think of it as equivalent to |
ysr@777 | 46 | // "_regions(100, true)": initialize the growable array and inform it |
kvn@2043 | 47 | // that it should allocate its elem array(s) on the C heap. |
kvn@2043 | 48 | // |
kvn@2043 | 49 | // The first argument, however, is actually a comma expression |
kvn@2043 | 50 | // (set_allocation_type(this, C_HEAP), 100). The purpose of the |
kvn@2043 | 51 | // set_allocation_type() call is to replace the default allocation |
kvn@2043 | 52 | // type for embedded objects STACK_OR_EMBEDDED with C_HEAP. It will |
kvn@2043 | 53 | // allow to pass the assert in GenericGrowableArray() which checks |
kvn@2043 | 54 | // that a growable array object must be on C heap if elements are. |
kvn@2043 | 55 | // |
kvn@2043 | 56 | // Note: containing object is allocated on C heap since it is CHeapObj. |
kvn@2043 | 57 | // |
kvn@2043 | 58 | _regions((ResourceObj::set_allocation_type((address)&_regions, |
kvn@2043 | 59 | ResourceObj::C_HEAP), |
iveresov@828 | 60 | (int)max_size), |
ysr@777 | 61 | true), |
ysr@777 | 62 | _next_rr_candidate(0), |
ysr@777 | 63 | _seq_bottom(NULL) |
ysr@777 | 64 | {} |
ysr@777 | 65 | |
ysr@777 | 66 | // Private methods. |
ysr@777 | 67 | |
apetrusenko@1112 | 68 | void HeapRegionSeq::print_empty_runs() { |
ysr@777 | 69 | int empty_run = 0; |
ysr@777 | 70 | int n_empty = 0; |
ysr@777 | 71 | int empty_run_start; |
ysr@777 | 72 | for (int i = 0; i < _regions.length(); i++) { |
ysr@777 | 73 | HeapRegion* r = _regions.at(i); |
ysr@777 | 74 | if (r->continuesHumongous()) continue; |
apetrusenko@1112 | 75 | if (r->is_empty()) { |
ysr@777 | 76 | assert(!r->isHumongous(), "H regions should not be empty."); |
ysr@777 | 77 | if (empty_run == 0) empty_run_start = i; |
ysr@777 | 78 | empty_run++; |
ysr@777 | 79 | n_empty++; |
ysr@777 | 80 | } else { |
ysr@777 | 81 | if (empty_run > 0) { |
ysr@777 | 82 | gclog_or_tty->print(" %d:%d", empty_run_start, empty_run); |
ysr@777 | 83 | empty_run = 0; |
ysr@777 | 84 | } |
ysr@777 | 85 | } |
ysr@777 | 86 | } |
ysr@777 | 87 | if (empty_run > 0) { |
ysr@777 | 88 | gclog_or_tty->print(" %d:%d", empty_run_start, empty_run); |
ysr@777 | 89 | } |
ysr@777 | 90 | gclog_or_tty->print_cr(" [tot = %d]", n_empty); |
ysr@777 | 91 | } |
ysr@777 | 92 | |
ysr@777 | 93 | int HeapRegionSeq::find(HeapRegion* hr) { |
ysr@777 | 94 | // FIXME: optimized for adjacent regions of fixed size. |
ysr@777 | 95 | int ind = hr->hrs_index(); |
ysr@777 | 96 | if (ind != -1) { |
ysr@777 | 97 | assert(_regions.at(ind) == hr, "Mismatch"); |
ysr@777 | 98 | } |
ysr@777 | 99 | return ind; |
ysr@777 | 100 | } |
ysr@777 | 101 | |
ysr@777 | 102 | |
ysr@777 | 103 | // Public methods. |
ysr@777 | 104 | |
ysr@777 | 105 | void HeapRegionSeq::insert(HeapRegion* hr) { |
iveresov@828 | 106 | assert(!_regions.is_full(), "Too many elements in HeapRegionSeq"); |
ysr@777 | 107 | if (_regions.length() == 0 |
ysr@777 | 108 | || _regions.top()->end() <= hr->bottom()) { |
ysr@777 | 109 | hr->set_hrs_index(_regions.length()); |
ysr@777 | 110 | _regions.append(hr); |
ysr@777 | 111 | } else { |
ysr@777 | 112 | _regions.append(hr); |
ysr@777 | 113 | _regions.sort(orderRegions); |
ysr@777 | 114 | for (int i = 0; i < _regions.length(); i++) { |
ysr@777 | 115 | _regions.at(i)->set_hrs_index(i); |
ysr@777 | 116 | } |
ysr@777 | 117 | } |
ysr@777 | 118 | char* bot = (char*)_regions.at(0)->bottom(); |
ysr@777 | 119 | if (_seq_bottom == NULL || bot < _seq_bottom) _seq_bottom = bot; |
ysr@777 | 120 | } |
ysr@777 | 121 | |
ysr@777 | 122 | size_t HeapRegionSeq::length() { |
ysr@777 | 123 | return _regions.length(); |
ysr@777 | 124 | } |
ysr@777 | 125 | |
ysr@777 | 126 | size_t HeapRegionSeq::free_suffix() { |
ysr@777 | 127 | size_t res = 0; |
ysr@777 | 128 | int first = _regions.length() - 1; |
ysr@777 | 129 | int cur = first; |
ysr@777 | 130 | while (cur >= 0 && |
ysr@777 | 131 | (_regions.at(cur)->is_empty() |
ysr@777 | 132 | && (first == cur |
ysr@777 | 133 | || (_regions.at(cur+1)->bottom() == |
ysr@777 | 134 | _regions.at(cur)->end())))) { |
ysr@777 | 135 | res++; |
ysr@777 | 136 | cur--; |
ysr@777 | 137 | } |
ysr@777 | 138 | return res; |
ysr@777 | 139 | } |
ysr@777 | 140 | |
tonyp@2472 | 141 | int HeapRegionSeq::find_contiguous_from(int from, size_t num) { |
tonyp@2472 | 142 | assert(num > 1, "pre-condition"); |
tonyp@2472 | 143 | assert(0 <= from && from <= _regions.length(), |
tonyp@2472 | 144 | err_msg("from: %d should be valid and <= than %d", |
tonyp@2472 | 145 | from, _regions.length())); |
tonyp@2472 | 146 | |
tonyp@2472 | 147 | int curr = from; |
tonyp@2472 | 148 | int first = -1; |
tonyp@2472 | 149 | size_t num_so_far = 0; |
tonyp@2472 | 150 | while (curr < _regions.length() && num_so_far < num) { |
tonyp@2472 | 151 | HeapRegion* curr_hr = _regions.at(curr); |
tonyp@2472 | 152 | if (curr_hr->is_empty()) { |
tonyp@2472 | 153 | if (first == -1) { |
tonyp@2472 | 154 | first = curr; |
tonyp@2472 | 155 | num_so_far = 1; |
tonyp@2472 | 156 | } else { |
tonyp@2472 | 157 | num_so_far += 1; |
tonyp@2472 | 158 | } |
tonyp@2472 | 159 | } else { |
tonyp@2472 | 160 | first = -1; |
tonyp@2472 | 161 | num_so_far = 0; |
tonyp@2472 | 162 | } |
tonyp@2472 | 163 | curr += 1; |
tonyp@2472 | 164 | } |
tonyp@2472 | 165 | |
tonyp@2472 | 166 | assert(num_so_far <= num, "post-condition"); |
tonyp@2472 | 167 | if (num_so_far == num) { |
tonyp@2643 | 168 | // we found enough space for the humongous object |
tonyp@2472 | 169 | assert(from <= first && first < _regions.length(), "post-condition"); |
tonyp@2472 | 170 | assert(first < curr && (curr - first) == (int) num, "post-condition"); |
tonyp@2472 | 171 | for (int i = first; i < first + (int) num; ++i) { |
tonyp@2472 | 172 | assert(_regions.at(i)->is_empty(), "post-condition"); |
tonyp@2472 | 173 | } |
tonyp@2472 | 174 | return first; |
tonyp@2472 | 175 | } else { |
tonyp@2472 | 176 | // we failed to find enough space for the humongous object |
tonyp@2472 | 177 | return -1; |
tonyp@2472 | 178 | } |
tonyp@2472 | 179 | } |
tonyp@2472 | 180 | |
tonyp@2472 | 181 | int HeapRegionSeq::find_contiguous(size_t num) { |
tonyp@2472 | 182 | assert(num > 1, "otherwise we should not be calling this"); |
tonyp@2472 | 183 | assert(0 <= _alloc_search_start && _alloc_search_start <= _regions.length(), |
tonyp@2472 | 184 | err_msg("_alloc_search_start: %d should be valid and <= than %d", |
tonyp@2472 | 185 | _alloc_search_start, _regions.length())); |
tonyp@2472 | 186 | |
tonyp@2472 | 187 | int start = _alloc_search_start; |
tonyp@2472 | 188 | int res = find_contiguous_from(start, num); |
tonyp@2472 | 189 | if (res == -1 && start != 0) { |
tonyp@2472 | 190 | // Try starting from the beginning. If _alloc_search_start was 0, |
tonyp@2472 | 191 | // no point in doing this again. |
tonyp@2472 | 192 | res = find_contiguous_from(0, num); |
tonyp@2472 | 193 | } |
tonyp@2472 | 194 | if (res != -1) { |
tonyp@2472 | 195 | assert(0 <= res && res < _regions.length(), |
tonyp@2472 | 196 | err_msg("res: %d should be valid", res)); |
tonyp@2472 | 197 | _alloc_search_start = res + (int) num; |
tonyp@2492 | 198 | assert(0 < _alloc_search_start && _alloc_search_start <= _regions.length(), |
tonyp@2492 | 199 | err_msg("_alloc_search_start: %d should be valid", |
tonyp@2492 | 200 | _alloc_search_start)); |
tonyp@2472 | 201 | } |
ysr@777 | 202 | return res; |
ysr@777 | 203 | } |
ysr@777 | 204 | |
ysr@777 | 205 | void HeapRegionSeq::iterate(HeapRegionClosure* blk) { |
ysr@777 | 206 | iterate_from((HeapRegion*)NULL, blk); |
ysr@777 | 207 | } |
ysr@777 | 208 | |
ysr@777 | 209 | // The first argument r is the heap region at which iteration begins. |
ysr@777 | 210 | // This operation runs fastest when r is NULL, or the heap region for |
ysr@777 | 211 | // which a HeapRegionClosure most recently returned true, or the |
ysr@777 | 212 | // heap region immediately to its right in the sequence. In all |
ysr@777 | 213 | // other cases a linear search is required to find the index of r. |
ysr@777 | 214 | |
ysr@777 | 215 | void HeapRegionSeq::iterate_from(HeapRegion* r, HeapRegionClosure* blk) { |
ysr@777 | 216 | |
ysr@777 | 217 | // :::: FIXME :::: |
ysr@777 | 218 | // Static cache value is bad, especially when we start doing parallel |
ysr@777 | 219 | // remembered set update. For now just don't cache anything (the |
ysr@777 | 220 | // code in the def'd out blocks). |
ysr@777 | 221 | |
ysr@777 | 222 | #if 0 |
ysr@777 | 223 | static int cached_j = 0; |
ysr@777 | 224 | #endif |
ysr@777 | 225 | int len = _regions.length(); |
ysr@777 | 226 | int j = 0; |
ysr@777 | 227 | // Find the index of r. |
ysr@777 | 228 | if (r != NULL) { |
ysr@777 | 229 | #if 0 |
ysr@777 | 230 | assert(cached_j >= 0, "Invariant."); |
ysr@777 | 231 | if ((cached_j < len) && (r == _regions.at(cached_j))) { |
ysr@777 | 232 | j = cached_j; |
ysr@777 | 233 | } else if ((cached_j + 1 < len) && (r == _regions.at(cached_j + 1))) { |
ysr@777 | 234 | j = cached_j + 1; |
ysr@777 | 235 | } else { |
ysr@777 | 236 | j = find(r); |
ysr@777 | 237 | #endif |
ysr@777 | 238 | if (j < 0) { |
ysr@777 | 239 | j = 0; |
ysr@777 | 240 | } |
ysr@777 | 241 | #if 0 |
ysr@777 | 242 | } |
ysr@777 | 243 | #endif |
ysr@777 | 244 | } |
ysr@777 | 245 | int i; |
ysr@777 | 246 | for (i = j; i < len; i += 1) { |
ysr@777 | 247 | int res = blk->doHeapRegion(_regions.at(i)); |
ysr@777 | 248 | if (res) { |
ysr@777 | 249 | #if 0 |
ysr@777 | 250 | cached_j = i; |
ysr@777 | 251 | #endif |
ysr@777 | 252 | blk->incomplete(); |
ysr@777 | 253 | return; |
ysr@777 | 254 | } |
ysr@777 | 255 | } |
ysr@777 | 256 | for (i = 0; i < j; i += 1) { |
ysr@777 | 257 | int res = blk->doHeapRegion(_regions.at(i)); |
ysr@777 | 258 | if (res) { |
ysr@777 | 259 | #if 0 |
ysr@777 | 260 | cached_j = i; |
ysr@777 | 261 | #endif |
ysr@777 | 262 | blk->incomplete(); |
ysr@777 | 263 | return; |
ysr@777 | 264 | } |
ysr@777 | 265 | } |
ysr@777 | 266 | } |
ysr@777 | 267 | |
ysr@777 | 268 | void HeapRegionSeq::iterate_from(int idx, HeapRegionClosure* blk) { |
ysr@777 | 269 | int len = _regions.length(); |
ysr@777 | 270 | int i; |
ysr@777 | 271 | for (i = idx; i < len; i++) { |
ysr@777 | 272 | if (blk->doHeapRegion(_regions.at(i))) { |
ysr@777 | 273 | blk->incomplete(); |
ysr@777 | 274 | return; |
ysr@777 | 275 | } |
ysr@777 | 276 | } |
ysr@777 | 277 | for (i = 0; i < idx; i++) { |
ysr@777 | 278 | if (blk->doHeapRegion(_regions.at(i))) { |
ysr@777 | 279 | blk->incomplete(); |
ysr@777 | 280 | return; |
ysr@777 | 281 | } |
ysr@777 | 282 | } |
ysr@777 | 283 | } |
ysr@777 | 284 | |
ysr@777 | 285 | MemRegion HeapRegionSeq::shrink_by(size_t shrink_bytes, |
ysr@777 | 286 | size_t& num_regions_deleted) { |
tonyp@2472 | 287 | // Reset this in case it's currently pointing into the regions that |
tonyp@2472 | 288 | // we just removed. |
tonyp@2472 | 289 | _alloc_search_start = 0; |
tonyp@2472 | 290 | |
ysr@777 | 291 | assert(shrink_bytes % os::vm_page_size() == 0, "unaligned"); |
ysr@777 | 292 | assert(shrink_bytes % HeapRegion::GrainBytes == 0, "unaligned"); |
ysr@777 | 293 | |
ysr@777 | 294 | if (_regions.length() == 0) { |
ysr@777 | 295 | num_regions_deleted = 0; |
ysr@777 | 296 | return MemRegion(); |
ysr@777 | 297 | } |
ysr@777 | 298 | int j = _regions.length() - 1; |
ysr@777 | 299 | HeapWord* end = _regions.at(j)->end(); |
ysr@777 | 300 | HeapWord* last_start = end; |
ysr@777 | 301 | while (j >= 0 && shrink_bytes > 0) { |
ysr@777 | 302 | HeapRegion* cur = _regions.at(j); |
ysr@777 | 303 | // We have to leave humongous regions where they are, |
ysr@777 | 304 | // and work around them. |
ysr@777 | 305 | if (cur->isHumongous()) { |
ysr@777 | 306 | return MemRegion(last_start, end); |
ysr@777 | 307 | } |
ysr@777 | 308 | assert(cur == _regions.top(), "Should be top"); |
ysr@777 | 309 | if (!cur->is_empty()) break; |
ysr@777 | 310 | shrink_bytes -= cur->capacity(); |
ysr@777 | 311 | num_regions_deleted++; |
ysr@777 | 312 | _regions.pop(); |
ysr@777 | 313 | last_start = cur->bottom(); |
ysr@777 | 314 | // We need to delete these somehow, but can't currently do so here: if |
ysr@777 | 315 | // we do, the ZF thread may still access the deleted region. We'll |
ysr@777 | 316 | // leave this here as a reminder that we have to do something about |
ysr@777 | 317 | // this. |
ysr@777 | 318 | // delete cur; |
ysr@777 | 319 | j--; |
ysr@777 | 320 | } |
ysr@777 | 321 | return MemRegion(last_start, end); |
ysr@777 | 322 | } |
ysr@777 | 323 | |
ysr@777 | 324 | class PrintHeapRegionClosure : public HeapRegionClosure { |
ysr@777 | 325 | public: |
ysr@777 | 326 | bool doHeapRegion(HeapRegion* r) { |
ysr@777 | 327 | gclog_or_tty->print(PTR_FORMAT ":", r); |
ysr@777 | 328 | r->print(); |
ysr@777 | 329 | return false; |
ysr@777 | 330 | } |
ysr@777 | 331 | }; |
ysr@777 | 332 | |
ysr@777 | 333 | void HeapRegionSeq::print() { |
ysr@777 | 334 | PrintHeapRegionClosure cl; |
ysr@777 | 335 | iterate(&cl); |
ysr@777 | 336 | } |