Mon, 16 Apr 2012 08:57:18 +0200
4988100: oop_verify_old_oop appears to be dead
Summary: removed oop_verify_old_oop and allow_dirty. Also reviewed by: alexlamsl@gmail.com
Reviewed-by: jmasa, jwilhelm
duke@435 | 1 | /* |
brutisso@3711 | 2 | * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 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. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
stefank@2314 | 25 | #include "precompiled.hpp" |
stefank@2314 | 26 | #include "gc_implementation/concurrentMarkSweep/cmsLockVerifier.hpp" |
stefank@2314 | 27 | #include "gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp" |
stefank@2314 | 28 | #include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.inline.hpp" |
stefank@2314 | 29 | #include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp" |
stefank@2314 | 30 | #include "gc_implementation/shared/liveRange.hpp" |
stefank@2314 | 31 | #include "gc_implementation/shared/spaceDecorator.hpp" |
stefank@2314 | 32 | #include "gc_interface/collectedHeap.hpp" |
stefank@2314 | 33 | #include "memory/allocation.inline.hpp" |
stefank@2314 | 34 | #include "memory/blockOffsetTable.inline.hpp" |
stefank@2314 | 35 | #include "memory/resourceArea.hpp" |
stefank@2314 | 36 | #include "memory/universe.inline.hpp" |
stefank@2314 | 37 | #include "oops/oop.inline.hpp" |
stefank@2314 | 38 | #include "runtime/globals.hpp" |
stefank@2314 | 39 | #include "runtime/handles.inline.hpp" |
stefank@2314 | 40 | #include "runtime/init.hpp" |
stefank@2314 | 41 | #include "runtime/java.hpp" |
stefank@2314 | 42 | #include "runtime/vmThread.hpp" |
stefank@2314 | 43 | #include "utilities/copy.hpp" |
duke@435 | 44 | |
duke@435 | 45 | ///////////////////////////////////////////////////////////////////////// |
duke@435 | 46 | //// CompactibleFreeListSpace |
duke@435 | 47 | ///////////////////////////////////////////////////////////////////////// |
duke@435 | 48 | |
duke@435 | 49 | // highest ranked free list lock rank |
duke@435 | 50 | int CompactibleFreeListSpace::_lockRank = Mutex::leaf + 3; |
duke@435 | 51 | |
kvn@1926 | 52 | // Defaults are 0 so things will break badly if incorrectly initialized. |
ysr@3264 | 53 | size_t CompactibleFreeListSpace::IndexSetStart = 0; |
ysr@3264 | 54 | size_t CompactibleFreeListSpace::IndexSetStride = 0; |
kvn@1926 | 55 | |
kvn@1926 | 56 | size_t MinChunkSize = 0; |
kvn@1926 | 57 | |
kvn@1926 | 58 | void CompactibleFreeListSpace::set_cms_values() { |
kvn@1926 | 59 | // Set CMS global values |
kvn@1926 | 60 | assert(MinChunkSize == 0, "already set"); |
kvn@1926 | 61 | #define numQuanta(x,y) ((x+y-1)/y) |
kvn@1926 | 62 | MinChunkSize = numQuanta(sizeof(FreeChunk), MinObjAlignmentInBytes) * MinObjAlignment; |
kvn@1926 | 63 | |
kvn@1926 | 64 | assert(IndexSetStart == 0 && IndexSetStride == 0, "already set"); |
ysr@3264 | 65 | IndexSetStart = MinChunkSize; |
kvn@1926 | 66 | IndexSetStride = MinObjAlignment; |
kvn@1926 | 67 | } |
kvn@1926 | 68 | |
duke@435 | 69 | // Constructor |
duke@435 | 70 | CompactibleFreeListSpace::CompactibleFreeListSpace(BlockOffsetSharedArray* bs, |
duke@435 | 71 | MemRegion mr, bool use_adaptive_freelists, |
duke@435 | 72 | FreeBlockDictionary::DictionaryChoice dictionaryChoice) : |
duke@435 | 73 | _dictionaryChoice(dictionaryChoice), |
duke@435 | 74 | _adaptive_freelists(use_adaptive_freelists), |
duke@435 | 75 | _bt(bs, mr), |
duke@435 | 76 | // free list locks are in the range of values taken by _lockRank |
duke@435 | 77 | // This range currently is [_leaf+2, _leaf+3] |
duke@435 | 78 | // Note: this requires that CFLspace c'tors |
duke@435 | 79 | // are called serially in the order in which the locks are |
duke@435 | 80 | // are acquired in the program text. This is true today. |
duke@435 | 81 | _freelistLock(_lockRank--, "CompactibleFreeListSpace._lock", true), |
duke@435 | 82 | _parDictionaryAllocLock(Mutex::leaf - 1, // == rank(ExpandHeap_lock) - 1 |
duke@435 | 83 | "CompactibleFreeListSpace._dict_par_lock", true), |
duke@435 | 84 | _rescan_task_size(CardTableModRefBS::card_size_in_words * BitsPerWord * |
duke@435 | 85 | CMSRescanMultiple), |
duke@435 | 86 | _marking_task_size(CardTableModRefBS::card_size_in_words * BitsPerWord * |
duke@435 | 87 | CMSConcMarkMultiple), |
duke@435 | 88 | _collector(NULL) |
duke@435 | 89 | { |
duke@435 | 90 | _bt.set_space(this); |
jmasa@698 | 91 | initialize(mr, SpaceDecorator::Clear, SpaceDecorator::Mangle); |
duke@435 | 92 | // We have all of "mr", all of which we place in the dictionary |
duke@435 | 93 | // as one big chunk. We'll need to decide here which of several |
duke@435 | 94 | // possible alternative dictionary implementations to use. For |
duke@435 | 95 | // now the choice is easy, since we have only one working |
duke@435 | 96 | // implementation, namely, the simple binary tree (splaying |
duke@435 | 97 | // temporarily disabled). |
duke@435 | 98 | switch (dictionaryChoice) { |
duke@435 | 99 | case FreeBlockDictionary::dictionarySplayTree: |
duke@435 | 100 | case FreeBlockDictionary::dictionarySkipList: |
duke@435 | 101 | default: |
duke@435 | 102 | warning("dictionaryChoice: selected option not understood; using" |
duke@435 | 103 | " default BinaryTreeDictionary implementation instead."); |
ysr@1580 | 104 | case FreeBlockDictionary::dictionaryBinaryTree: |
duke@435 | 105 | _dictionary = new BinaryTreeDictionary(mr); |
duke@435 | 106 | break; |
duke@435 | 107 | } |
duke@435 | 108 | assert(_dictionary != NULL, "CMS dictionary initialization"); |
duke@435 | 109 | // The indexed free lists are initially all empty and are lazily |
duke@435 | 110 | // filled in on demand. Initialize the array elements to NULL. |
duke@435 | 111 | initializeIndexedFreeListArray(); |
duke@435 | 112 | |
duke@435 | 113 | // Not using adaptive free lists assumes that allocation is first |
duke@435 | 114 | // from the linAB's. Also a cms perm gen which can be compacted |
duke@435 | 115 | // has to have the klass's klassKlass allocated at a lower |
duke@435 | 116 | // address in the heap than the klass so that the klassKlass is |
duke@435 | 117 | // moved to its new location before the klass is moved. |
duke@435 | 118 | // Set the _refillSize for the linear allocation blocks |
duke@435 | 119 | if (!use_adaptive_freelists) { |
duke@435 | 120 | FreeChunk* fc = _dictionary->getChunk(mr.word_size()); |
duke@435 | 121 | // The small linAB initially has all the space and will allocate |
duke@435 | 122 | // a chunk of any size. |
duke@435 | 123 | HeapWord* addr = (HeapWord*) fc; |
duke@435 | 124 | _smallLinearAllocBlock.set(addr, fc->size() , |
duke@435 | 125 | 1024*SmallForLinearAlloc, fc->size()); |
duke@435 | 126 | // Note that _unallocated_block is not updated here. |
duke@435 | 127 | // Allocations from the linear allocation block should |
duke@435 | 128 | // update it. |
duke@435 | 129 | } else { |
duke@435 | 130 | _smallLinearAllocBlock.set(0, 0, 1024*SmallForLinearAlloc, |
duke@435 | 131 | SmallForLinearAlloc); |
duke@435 | 132 | } |
duke@435 | 133 | // CMSIndexedFreeListReplenish should be at least 1 |
duke@435 | 134 | CMSIndexedFreeListReplenish = MAX2((uintx)1, CMSIndexedFreeListReplenish); |
duke@435 | 135 | _promoInfo.setSpace(this); |
duke@435 | 136 | if (UseCMSBestFit) { |
duke@435 | 137 | _fitStrategy = FreeBlockBestFitFirst; |
duke@435 | 138 | } else { |
duke@435 | 139 | _fitStrategy = FreeBlockStrategyNone; |
duke@435 | 140 | } |
ysr@3220 | 141 | check_free_list_consistency(); |
duke@435 | 142 | |
duke@435 | 143 | // Initialize locks for parallel case. |
jmasa@2188 | 144 | |
jmasa@2188 | 145 | if (CollectedHeap::use_parallel_gc_threads()) { |
duke@435 | 146 | for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 147 | _indexedFreeListParLocks[i] = new Mutex(Mutex::leaf - 1, // == ExpandHeap_lock - 1 |
duke@435 | 148 | "a freelist par lock", |
duke@435 | 149 | true); |
duke@435 | 150 | if (_indexedFreeListParLocks[i] == NULL) |
duke@435 | 151 | vm_exit_during_initialization("Could not allocate a par lock"); |
duke@435 | 152 | DEBUG_ONLY( |
duke@435 | 153 | _indexedFreeList[i].set_protecting_lock(_indexedFreeListParLocks[i]); |
duke@435 | 154 | ) |
duke@435 | 155 | } |
duke@435 | 156 | _dictionary->set_par_lock(&_parDictionaryAllocLock); |
duke@435 | 157 | } |
duke@435 | 158 | } |
duke@435 | 159 | |
duke@435 | 160 | // Like CompactibleSpace forward() but always calls cross_threshold() to |
duke@435 | 161 | // update the block offset table. Removed initialize_threshold call because |
duke@435 | 162 | // CFLS does not use a block offset array for contiguous spaces. |
duke@435 | 163 | HeapWord* CompactibleFreeListSpace::forward(oop q, size_t size, |
duke@435 | 164 | CompactPoint* cp, HeapWord* compact_top) { |
duke@435 | 165 | // q is alive |
duke@435 | 166 | // First check if we should switch compaction space |
duke@435 | 167 | assert(this == cp->space, "'this' should be current compaction space."); |
duke@435 | 168 | size_t compaction_max_size = pointer_delta(end(), compact_top); |
duke@435 | 169 | assert(adjustObjectSize(size) == cp->space->adjust_object_size_v(size), |
duke@435 | 170 | "virtual adjustObjectSize_v() method is not correct"); |
duke@435 | 171 | size_t adjusted_size = adjustObjectSize(size); |
duke@435 | 172 | assert(compaction_max_size >= MinChunkSize || compaction_max_size == 0, |
duke@435 | 173 | "no small fragments allowed"); |
duke@435 | 174 | assert(minimum_free_block_size() == MinChunkSize, |
duke@435 | 175 | "for de-virtualized reference below"); |
duke@435 | 176 | // Can't leave a nonzero size, residual fragment smaller than MinChunkSize |
duke@435 | 177 | if (adjusted_size + MinChunkSize > compaction_max_size && |
duke@435 | 178 | adjusted_size != compaction_max_size) { |
duke@435 | 179 | do { |
duke@435 | 180 | // switch to next compaction space |
duke@435 | 181 | cp->space->set_compaction_top(compact_top); |
duke@435 | 182 | cp->space = cp->space->next_compaction_space(); |
duke@435 | 183 | if (cp->space == NULL) { |
duke@435 | 184 | cp->gen = GenCollectedHeap::heap()->prev_gen(cp->gen); |
duke@435 | 185 | assert(cp->gen != NULL, "compaction must succeed"); |
duke@435 | 186 | cp->space = cp->gen->first_compaction_space(); |
duke@435 | 187 | assert(cp->space != NULL, "generation must have a first compaction space"); |
duke@435 | 188 | } |
duke@435 | 189 | compact_top = cp->space->bottom(); |
duke@435 | 190 | cp->space->set_compaction_top(compact_top); |
duke@435 | 191 | // The correct adjusted_size may not be the same as that for this method |
duke@435 | 192 | // (i.e., cp->space may no longer be "this" so adjust the size again. |
duke@435 | 193 | // Use the virtual method which is not used above to save the virtual |
duke@435 | 194 | // dispatch. |
duke@435 | 195 | adjusted_size = cp->space->adjust_object_size_v(size); |
duke@435 | 196 | compaction_max_size = pointer_delta(cp->space->end(), compact_top); |
duke@435 | 197 | assert(cp->space->minimum_free_block_size() == 0, "just checking"); |
duke@435 | 198 | } while (adjusted_size > compaction_max_size); |
duke@435 | 199 | } |
duke@435 | 200 | |
duke@435 | 201 | // store the forwarding pointer into the mark word |
duke@435 | 202 | if ((HeapWord*)q != compact_top) { |
duke@435 | 203 | q->forward_to(oop(compact_top)); |
duke@435 | 204 | assert(q->is_gc_marked(), "encoding the pointer should preserve the mark"); |
duke@435 | 205 | } else { |
duke@435 | 206 | // if the object isn't moving we can just set the mark to the default |
duke@435 | 207 | // mark and handle it specially later on. |
duke@435 | 208 | q->init_mark(); |
duke@435 | 209 | assert(q->forwardee() == NULL, "should be forwarded to NULL"); |
duke@435 | 210 | } |
duke@435 | 211 | |
coleenp@548 | 212 | VALIDATE_MARK_SWEEP_ONLY(MarkSweep::register_live_oop(q, adjusted_size)); |
duke@435 | 213 | compact_top += adjusted_size; |
duke@435 | 214 | |
duke@435 | 215 | // we need to update the offset table so that the beginnings of objects can be |
duke@435 | 216 | // found during scavenge. Note that we are updating the offset table based on |
duke@435 | 217 | // where the object will be once the compaction phase finishes. |
duke@435 | 218 | |
duke@435 | 219 | // Always call cross_threshold(). A contiguous space can only call it when |
duke@435 | 220 | // the compaction_top exceeds the current threshold but not for an |
duke@435 | 221 | // non-contiguous space. |
duke@435 | 222 | cp->threshold = |
duke@435 | 223 | cp->space->cross_threshold(compact_top - adjusted_size, compact_top); |
duke@435 | 224 | return compact_top; |
duke@435 | 225 | } |
duke@435 | 226 | |
duke@435 | 227 | // A modified copy of OffsetTableContigSpace::cross_threshold() with _offsets -> _bt |
duke@435 | 228 | // and use of single_block instead of alloc_block. The name here is not really |
duke@435 | 229 | // appropriate - maybe a more general name could be invented for both the |
duke@435 | 230 | // contiguous and noncontiguous spaces. |
duke@435 | 231 | |
duke@435 | 232 | HeapWord* CompactibleFreeListSpace::cross_threshold(HeapWord* start, HeapWord* the_end) { |
duke@435 | 233 | _bt.single_block(start, the_end); |
duke@435 | 234 | return end(); |
duke@435 | 235 | } |
duke@435 | 236 | |
duke@435 | 237 | // Initialize them to NULL. |
duke@435 | 238 | void CompactibleFreeListSpace::initializeIndexedFreeListArray() { |
duke@435 | 239 | for (size_t i = 0; i < IndexSetSize; i++) { |
duke@435 | 240 | // Note that on platforms where objects are double word aligned, |
duke@435 | 241 | // the odd array elements are not used. It is convenient, however, |
duke@435 | 242 | // to map directly from the object size to the array element. |
duke@435 | 243 | _indexedFreeList[i].reset(IndexSetSize); |
duke@435 | 244 | _indexedFreeList[i].set_size(i); |
duke@435 | 245 | assert(_indexedFreeList[i].count() == 0, "reset check failed"); |
duke@435 | 246 | assert(_indexedFreeList[i].head() == NULL, "reset check failed"); |
duke@435 | 247 | assert(_indexedFreeList[i].tail() == NULL, "reset check failed"); |
duke@435 | 248 | assert(_indexedFreeList[i].hint() == IndexSetSize, "reset check failed"); |
duke@435 | 249 | } |
duke@435 | 250 | } |
duke@435 | 251 | |
duke@435 | 252 | void CompactibleFreeListSpace::resetIndexedFreeListArray() { |
ysr@3264 | 253 | for (size_t i = 1; i < IndexSetSize; i++) { |
duke@435 | 254 | assert(_indexedFreeList[i].size() == (size_t) i, |
duke@435 | 255 | "Indexed free list sizes are incorrect"); |
duke@435 | 256 | _indexedFreeList[i].reset(IndexSetSize); |
duke@435 | 257 | assert(_indexedFreeList[i].count() == 0, "reset check failed"); |
duke@435 | 258 | assert(_indexedFreeList[i].head() == NULL, "reset check failed"); |
duke@435 | 259 | assert(_indexedFreeList[i].tail() == NULL, "reset check failed"); |
duke@435 | 260 | assert(_indexedFreeList[i].hint() == IndexSetSize, "reset check failed"); |
duke@435 | 261 | } |
duke@435 | 262 | } |
duke@435 | 263 | |
duke@435 | 264 | void CompactibleFreeListSpace::reset(MemRegion mr) { |
duke@435 | 265 | resetIndexedFreeListArray(); |
duke@435 | 266 | dictionary()->reset(); |
duke@435 | 267 | if (BlockOffsetArrayUseUnallocatedBlock) { |
duke@435 | 268 | assert(end() == mr.end(), "We are compacting to the bottom of CMS gen"); |
duke@435 | 269 | // Everything's allocated until proven otherwise. |
duke@435 | 270 | _bt.set_unallocated_block(end()); |
duke@435 | 271 | } |
duke@435 | 272 | if (!mr.is_empty()) { |
duke@435 | 273 | assert(mr.word_size() >= MinChunkSize, "Chunk size is too small"); |
duke@435 | 274 | _bt.single_block(mr.start(), mr.word_size()); |
duke@435 | 275 | FreeChunk* fc = (FreeChunk*) mr.start(); |
duke@435 | 276 | fc->setSize(mr.word_size()); |
duke@435 | 277 | if (mr.word_size() >= IndexSetSize ) { |
duke@435 | 278 | returnChunkToDictionary(fc); |
duke@435 | 279 | } else { |
duke@435 | 280 | _bt.verify_not_unallocated((HeapWord*)fc, fc->size()); |
duke@435 | 281 | _indexedFreeList[mr.word_size()].returnChunkAtHead(fc); |
duke@435 | 282 | } |
duke@435 | 283 | } |
duke@435 | 284 | _promoInfo.reset(); |
duke@435 | 285 | _smallLinearAllocBlock._ptr = NULL; |
duke@435 | 286 | _smallLinearAllocBlock._word_size = 0; |
duke@435 | 287 | } |
duke@435 | 288 | |
duke@435 | 289 | void CompactibleFreeListSpace::reset_after_compaction() { |
duke@435 | 290 | // Reset the space to the new reality - one free chunk. |
duke@435 | 291 | MemRegion mr(compaction_top(), end()); |
duke@435 | 292 | reset(mr); |
duke@435 | 293 | // Now refill the linear allocation block(s) if possible. |
duke@435 | 294 | if (_adaptive_freelists) { |
duke@435 | 295 | refillLinearAllocBlocksIfNeeded(); |
duke@435 | 296 | } else { |
duke@435 | 297 | // Place as much of mr in the linAB as we can get, |
duke@435 | 298 | // provided it was big enough to go into the dictionary. |
duke@435 | 299 | FreeChunk* fc = dictionary()->findLargestDict(); |
duke@435 | 300 | if (fc != NULL) { |
duke@435 | 301 | assert(fc->size() == mr.word_size(), |
duke@435 | 302 | "Why was the chunk broken up?"); |
duke@435 | 303 | removeChunkFromDictionary(fc); |
duke@435 | 304 | HeapWord* addr = (HeapWord*) fc; |
duke@435 | 305 | _smallLinearAllocBlock.set(addr, fc->size() , |
duke@435 | 306 | 1024*SmallForLinearAlloc, fc->size()); |
duke@435 | 307 | // Note that _unallocated_block is not updated here. |
duke@435 | 308 | } |
duke@435 | 309 | } |
duke@435 | 310 | } |
duke@435 | 311 | |
duke@435 | 312 | // Walks the entire dictionary, returning a coterminal |
duke@435 | 313 | // chunk, if it exists. Use with caution since it involves |
duke@435 | 314 | // a potentially complete walk of a potentially large tree. |
duke@435 | 315 | FreeChunk* CompactibleFreeListSpace::find_chunk_at_end() { |
duke@435 | 316 | |
duke@435 | 317 | assert_lock_strong(&_freelistLock); |
duke@435 | 318 | |
duke@435 | 319 | return dictionary()->find_chunk_ends_at(end()); |
duke@435 | 320 | } |
duke@435 | 321 | |
duke@435 | 322 | |
duke@435 | 323 | #ifndef PRODUCT |
duke@435 | 324 | void CompactibleFreeListSpace::initializeIndexedFreeListArrayReturnedBytes() { |
duke@435 | 325 | for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 326 | _indexedFreeList[i].allocation_stats()->set_returnedBytes(0); |
duke@435 | 327 | } |
duke@435 | 328 | } |
duke@435 | 329 | |
duke@435 | 330 | size_t CompactibleFreeListSpace::sumIndexedFreeListArrayReturnedBytes() { |
duke@435 | 331 | size_t sum = 0; |
duke@435 | 332 | for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 333 | sum += _indexedFreeList[i].allocation_stats()->returnedBytes(); |
duke@435 | 334 | } |
duke@435 | 335 | return sum; |
duke@435 | 336 | } |
duke@435 | 337 | |
duke@435 | 338 | size_t CompactibleFreeListSpace::totalCountInIndexedFreeLists() const { |
duke@435 | 339 | size_t count = 0; |
ysr@3264 | 340 | for (size_t i = IndexSetStart; i < IndexSetSize; i++) { |
duke@435 | 341 | debug_only( |
duke@435 | 342 | ssize_t total_list_count = 0; |
duke@435 | 343 | for (FreeChunk* fc = _indexedFreeList[i].head(); fc != NULL; |
duke@435 | 344 | fc = fc->next()) { |
duke@435 | 345 | total_list_count++; |
duke@435 | 346 | } |
duke@435 | 347 | assert(total_list_count == _indexedFreeList[i].count(), |
duke@435 | 348 | "Count in list is incorrect"); |
duke@435 | 349 | ) |
duke@435 | 350 | count += _indexedFreeList[i].count(); |
duke@435 | 351 | } |
duke@435 | 352 | return count; |
duke@435 | 353 | } |
duke@435 | 354 | |
duke@435 | 355 | size_t CompactibleFreeListSpace::totalCount() { |
duke@435 | 356 | size_t num = totalCountInIndexedFreeLists(); |
duke@435 | 357 | num += dictionary()->totalCount(); |
duke@435 | 358 | if (_smallLinearAllocBlock._word_size != 0) { |
duke@435 | 359 | num++; |
duke@435 | 360 | } |
duke@435 | 361 | return num; |
duke@435 | 362 | } |
duke@435 | 363 | #endif |
duke@435 | 364 | |
duke@435 | 365 | bool CompactibleFreeListSpace::is_free_block(const HeapWord* p) const { |
duke@435 | 366 | FreeChunk* fc = (FreeChunk*) p; |
duke@435 | 367 | return fc->isFree(); |
duke@435 | 368 | } |
duke@435 | 369 | |
duke@435 | 370 | size_t CompactibleFreeListSpace::used() const { |
duke@435 | 371 | return capacity() - free(); |
duke@435 | 372 | } |
duke@435 | 373 | |
duke@435 | 374 | size_t CompactibleFreeListSpace::free() const { |
duke@435 | 375 | // "MT-safe, but not MT-precise"(TM), if you will: i.e. |
duke@435 | 376 | // if you do this while the structures are in flux you |
duke@435 | 377 | // may get an approximate answer only; for instance |
duke@435 | 378 | // because there is concurrent allocation either |
duke@435 | 379 | // directly by mutators or for promotion during a GC. |
duke@435 | 380 | // It's "MT-safe", however, in the sense that you are guaranteed |
duke@435 | 381 | // not to crash and burn, for instance, because of walking |
duke@435 | 382 | // pointers that could disappear as you were walking them. |
duke@435 | 383 | // The approximation is because the various components |
duke@435 | 384 | // that are read below are not read atomically (and |
duke@435 | 385 | // further the computation of totalSizeInIndexedFreeLists() |
duke@435 | 386 | // is itself a non-atomic computation. The normal use of |
duke@435 | 387 | // this is during a resize operation at the end of GC |
duke@435 | 388 | // and at that time you are guaranteed to get the |
duke@435 | 389 | // correct actual value. However, for instance, this is |
duke@435 | 390 | // also read completely asynchronously by the "perf-sampler" |
duke@435 | 391 | // that supports jvmstat, and you are apt to see the values |
duke@435 | 392 | // flicker in such cases. |
duke@435 | 393 | assert(_dictionary != NULL, "No _dictionary?"); |
duke@435 | 394 | return (_dictionary->totalChunkSize(DEBUG_ONLY(freelistLock())) + |
duke@435 | 395 | totalSizeInIndexedFreeLists() + |
duke@435 | 396 | _smallLinearAllocBlock._word_size) * HeapWordSize; |
duke@435 | 397 | } |
duke@435 | 398 | |
duke@435 | 399 | size_t CompactibleFreeListSpace::max_alloc_in_words() const { |
duke@435 | 400 | assert(_dictionary != NULL, "No _dictionary?"); |
duke@435 | 401 | assert_locked(); |
duke@435 | 402 | size_t res = _dictionary->maxChunkSize(); |
duke@435 | 403 | res = MAX2(res, MIN2(_smallLinearAllocBlock._word_size, |
duke@435 | 404 | (size_t) SmallForLinearAlloc - 1)); |
duke@435 | 405 | // XXX the following could potentially be pretty slow; |
duke@435 | 406 | // should one, pesimally for the rare cases when res |
duke@435 | 407 | // caclulated above is less than IndexSetSize, |
duke@435 | 408 | // just return res calculated above? My reasoning was that |
duke@435 | 409 | // those cases will be so rare that the extra time spent doesn't |
duke@435 | 410 | // really matter.... |
duke@435 | 411 | // Note: do not change the loop test i >= res + IndexSetStride |
duke@435 | 412 | // to i > res below, because i is unsigned and res may be zero. |
duke@435 | 413 | for (size_t i = IndexSetSize - 1; i >= res + IndexSetStride; |
duke@435 | 414 | i -= IndexSetStride) { |
duke@435 | 415 | if (_indexedFreeList[i].head() != NULL) { |
duke@435 | 416 | assert(_indexedFreeList[i].count() != 0, "Inconsistent FreeList"); |
duke@435 | 417 | return i; |
duke@435 | 418 | } |
duke@435 | 419 | } |
duke@435 | 420 | return res; |
duke@435 | 421 | } |
duke@435 | 422 | |
ysr@2071 | 423 | void LinearAllocBlock::print_on(outputStream* st) const { |
ysr@2071 | 424 | st->print_cr(" LinearAllocBlock: ptr = " PTR_FORMAT ", word_size = " SIZE_FORMAT |
ysr@2071 | 425 | ", refillsize = " SIZE_FORMAT ", allocation_size_limit = " SIZE_FORMAT, |
ysr@2071 | 426 | _ptr, _word_size, _refillSize, _allocation_size_limit); |
ysr@2071 | 427 | } |
ysr@2071 | 428 | |
ysr@2071 | 429 | void CompactibleFreeListSpace::print_on(outputStream* st) const { |
ysr@2071 | 430 | st->print_cr("COMPACTIBLE FREELIST SPACE"); |
ysr@2071 | 431 | st->print_cr(" Space:"); |
ysr@2071 | 432 | Space::print_on(st); |
ysr@2071 | 433 | |
ysr@2071 | 434 | st->print_cr("promoInfo:"); |
ysr@2071 | 435 | _promoInfo.print_on(st); |
ysr@2071 | 436 | |
ysr@2071 | 437 | st->print_cr("_smallLinearAllocBlock"); |
ysr@2071 | 438 | _smallLinearAllocBlock.print_on(st); |
ysr@2071 | 439 | |
ysr@2071 | 440 | // dump_memory_block(_smallLinearAllocBlock->_ptr, 128); |
ysr@2071 | 441 | |
ysr@2071 | 442 | st->print_cr(" _fitStrategy = %s, _adaptive_freelists = %s", |
ysr@2071 | 443 | _fitStrategy?"true":"false", _adaptive_freelists?"true":"false"); |
ysr@2071 | 444 | } |
ysr@2071 | 445 | |
ysr@1580 | 446 | void CompactibleFreeListSpace::print_indexed_free_lists(outputStream* st) |
ysr@1580 | 447 | const { |
ysr@1580 | 448 | reportIndexedFreeListStatistics(); |
ysr@1580 | 449 | gclog_or_tty->print_cr("Layout of Indexed Freelists"); |
ysr@1580 | 450 | gclog_or_tty->print_cr("---------------------------"); |
ysr@1580 | 451 | FreeList::print_labels_on(st, "size"); |
ysr@1580 | 452 | for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
ysr@1580 | 453 | _indexedFreeList[i].print_on(gclog_or_tty); |
ysr@1580 | 454 | for (FreeChunk* fc = _indexedFreeList[i].head(); fc != NULL; |
ysr@1580 | 455 | fc = fc->next()) { |
ysr@1580 | 456 | gclog_or_tty->print_cr("\t[" PTR_FORMAT "," PTR_FORMAT ") %s", |
ysr@1580 | 457 | fc, (HeapWord*)fc + i, |
ysr@1580 | 458 | fc->cantCoalesce() ? "\t CC" : ""); |
ysr@1580 | 459 | } |
ysr@1580 | 460 | } |
ysr@1580 | 461 | } |
ysr@1580 | 462 | |
ysr@1580 | 463 | void CompactibleFreeListSpace::print_promo_info_blocks(outputStream* st) |
ysr@1580 | 464 | const { |
ysr@1580 | 465 | _promoInfo.print_on(st); |
ysr@1580 | 466 | } |
ysr@1580 | 467 | |
ysr@1580 | 468 | void CompactibleFreeListSpace::print_dictionary_free_lists(outputStream* st) |
ysr@1580 | 469 | const { |
ysr@1580 | 470 | _dictionary->reportStatistics(); |
ysr@1580 | 471 | st->print_cr("Layout of Freelists in Tree"); |
ysr@1580 | 472 | st->print_cr("---------------------------"); |
ysr@1580 | 473 | _dictionary->print_free_lists(st); |
ysr@1580 | 474 | } |
ysr@1580 | 475 | |
ysr@1580 | 476 | class BlkPrintingClosure: public BlkClosure { |
ysr@1580 | 477 | const CMSCollector* _collector; |
ysr@1580 | 478 | const CompactibleFreeListSpace* _sp; |
ysr@1580 | 479 | const CMSBitMap* _live_bit_map; |
ysr@1580 | 480 | const bool _post_remark; |
ysr@1580 | 481 | outputStream* _st; |
ysr@1580 | 482 | public: |
ysr@1580 | 483 | BlkPrintingClosure(const CMSCollector* collector, |
ysr@1580 | 484 | const CompactibleFreeListSpace* sp, |
ysr@1580 | 485 | const CMSBitMap* live_bit_map, |
ysr@1580 | 486 | outputStream* st): |
ysr@1580 | 487 | _collector(collector), |
ysr@1580 | 488 | _sp(sp), |
ysr@1580 | 489 | _live_bit_map(live_bit_map), |
ysr@1580 | 490 | _post_remark(collector->abstract_state() > CMSCollector::FinalMarking), |
ysr@1580 | 491 | _st(st) { } |
ysr@1580 | 492 | size_t do_blk(HeapWord* addr); |
ysr@1580 | 493 | }; |
ysr@1580 | 494 | |
ysr@1580 | 495 | size_t BlkPrintingClosure::do_blk(HeapWord* addr) { |
ysr@1580 | 496 | size_t sz = _sp->block_size_no_stall(addr, _collector); |
ysr@1580 | 497 | assert(sz != 0, "Should always be able to compute a size"); |
ysr@1580 | 498 | if (_sp->block_is_obj(addr)) { |
ysr@1580 | 499 | const bool dead = _post_remark && !_live_bit_map->isMarked(addr); |
ysr@1580 | 500 | _st->print_cr(PTR_FORMAT ": %s object of size " SIZE_FORMAT "%s", |
ysr@1580 | 501 | addr, |
ysr@1580 | 502 | dead ? "dead" : "live", |
ysr@1580 | 503 | sz, |
ysr@1580 | 504 | (!dead && CMSPrintObjectsInDump) ? ":" : "."); |
ysr@1580 | 505 | if (CMSPrintObjectsInDump && !dead) { |
ysr@1580 | 506 | oop(addr)->print_on(_st); |
ysr@1580 | 507 | _st->print_cr("--------------------------------------"); |
ysr@1580 | 508 | } |
ysr@1580 | 509 | } else { // free block |
ysr@1580 | 510 | _st->print_cr(PTR_FORMAT ": free block of size " SIZE_FORMAT "%s", |
ysr@1580 | 511 | addr, sz, CMSPrintChunksInDump ? ":" : "."); |
ysr@1580 | 512 | if (CMSPrintChunksInDump) { |
ysr@1580 | 513 | ((FreeChunk*)addr)->print_on(_st); |
ysr@1580 | 514 | _st->print_cr("--------------------------------------"); |
ysr@1580 | 515 | } |
ysr@1580 | 516 | } |
ysr@1580 | 517 | return sz; |
ysr@1580 | 518 | } |
ysr@1580 | 519 | |
ysr@1580 | 520 | void CompactibleFreeListSpace::dump_at_safepoint_with_locks(CMSCollector* c, |
ysr@1580 | 521 | outputStream* st) { |
ysr@1580 | 522 | st->print_cr("\n========================="); |
ysr@1580 | 523 | st->print_cr("Block layout in CMS Heap:"); |
ysr@1580 | 524 | st->print_cr("========================="); |
ysr@1580 | 525 | BlkPrintingClosure bpcl(c, this, c->markBitMap(), st); |
ysr@1580 | 526 | blk_iterate(&bpcl); |
ysr@1580 | 527 | |
ysr@1580 | 528 | st->print_cr("\n======================================="); |
ysr@1580 | 529 | st->print_cr("Order & Layout of Promotion Info Blocks"); |
ysr@1580 | 530 | st->print_cr("======================================="); |
ysr@1580 | 531 | print_promo_info_blocks(st); |
ysr@1580 | 532 | |
ysr@1580 | 533 | st->print_cr("\n==========================="); |
ysr@1580 | 534 | st->print_cr("Order of Indexed Free Lists"); |
ysr@1580 | 535 | st->print_cr("========================="); |
ysr@1580 | 536 | print_indexed_free_lists(st); |
ysr@1580 | 537 | |
ysr@1580 | 538 | st->print_cr("\n================================="); |
ysr@1580 | 539 | st->print_cr("Order of Free Lists in Dictionary"); |
ysr@1580 | 540 | st->print_cr("================================="); |
ysr@1580 | 541 | print_dictionary_free_lists(st); |
ysr@1580 | 542 | } |
ysr@1580 | 543 | |
ysr@1580 | 544 | |
duke@435 | 545 | void CompactibleFreeListSpace::reportFreeListStatistics() const { |
duke@435 | 546 | assert_lock_strong(&_freelistLock); |
duke@435 | 547 | assert(PrintFLSStatistics != 0, "Reporting error"); |
duke@435 | 548 | _dictionary->reportStatistics(); |
duke@435 | 549 | if (PrintFLSStatistics > 1) { |
duke@435 | 550 | reportIndexedFreeListStatistics(); |
duke@435 | 551 | size_t totalSize = totalSizeInIndexedFreeLists() + |
duke@435 | 552 | _dictionary->totalChunkSize(DEBUG_ONLY(freelistLock())); |
duke@435 | 553 | gclog_or_tty->print(" free=%ld frag=%1.4f\n", totalSize, flsFrag()); |
duke@435 | 554 | } |
duke@435 | 555 | } |
duke@435 | 556 | |
duke@435 | 557 | void CompactibleFreeListSpace::reportIndexedFreeListStatistics() const { |
duke@435 | 558 | assert_lock_strong(&_freelistLock); |
duke@435 | 559 | gclog_or_tty->print("Statistics for IndexedFreeLists:\n" |
duke@435 | 560 | "--------------------------------\n"); |
duke@435 | 561 | size_t totalSize = totalSizeInIndexedFreeLists(); |
duke@435 | 562 | size_t freeBlocks = numFreeBlocksInIndexedFreeLists(); |
duke@435 | 563 | gclog_or_tty->print("Total Free Space: %d\n", totalSize); |
duke@435 | 564 | gclog_or_tty->print("Max Chunk Size: %d\n", maxChunkSizeInIndexedFreeLists()); |
duke@435 | 565 | gclog_or_tty->print("Number of Blocks: %d\n", freeBlocks); |
duke@435 | 566 | if (freeBlocks != 0) { |
duke@435 | 567 | gclog_or_tty->print("Av. Block Size: %d\n", totalSize/freeBlocks); |
duke@435 | 568 | } |
duke@435 | 569 | } |
duke@435 | 570 | |
duke@435 | 571 | size_t CompactibleFreeListSpace::numFreeBlocksInIndexedFreeLists() const { |
duke@435 | 572 | size_t res = 0; |
duke@435 | 573 | for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 574 | debug_only( |
duke@435 | 575 | ssize_t recount = 0; |
duke@435 | 576 | for (FreeChunk* fc = _indexedFreeList[i].head(); fc != NULL; |
duke@435 | 577 | fc = fc->next()) { |
duke@435 | 578 | recount += 1; |
duke@435 | 579 | } |
duke@435 | 580 | assert(recount == _indexedFreeList[i].count(), |
duke@435 | 581 | "Incorrect count in list"); |
duke@435 | 582 | ) |
duke@435 | 583 | res += _indexedFreeList[i].count(); |
duke@435 | 584 | } |
duke@435 | 585 | return res; |
duke@435 | 586 | } |
duke@435 | 587 | |
duke@435 | 588 | size_t CompactibleFreeListSpace::maxChunkSizeInIndexedFreeLists() const { |
duke@435 | 589 | for (size_t i = IndexSetSize - 1; i != 0; i -= IndexSetStride) { |
duke@435 | 590 | if (_indexedFreeList[i].head() != NULL) { |
duke@435 | 591 | assert(_indexedFreeList[i].count() != 0, "Inconsistent FreeList"); |
duke@435 | 592 | return (size_t)i; |
duke@435 | 593 | } |
duke@435 | 594 | } |
duke@435 | 595 | return 0; |
duke@435 | 596 | } |
duke@435 | 597 | |
duke@435 | 598 | void CompactibleFreeListSpace::set_end(HeapWord* value) { |
duke@435 | 599 | HeapWord* prevEnd = end(); |
duke@435 | 600 | assert(prevEnd != value, "unnecessary set_end call"); |
ysr@2071 | 601 | assert(prevEnd == NULL || !BlockOffsetArrayUseUnallocatedBlock || value >= unallocated_block(), |
ysr@2071 | 602 | "New end is below unallocated block"); |
duke@435 | 603 | _end = value; |
duke@435 | 604 | if (prevEnd != NULL) { |
duke@435 | 605 | // Resize the underlying block offset table. |
duke@435 | 606 | _bt.resize(pointer_delta(value, bottom())); |
ysr@1580 | 607 | if (value <= prevEnd) { |
ysr@2071 | 608 | assert(!BlockOffsetArrayUseUnallocatedBlock || value >= unallocated_block(), |
ysr@2071 | 609 | "New end is below unallocated block"); |
ysr@1580 | 610 | } else { |
ysr@1580 | 611 | // Now, take this new chunk and add it to the free blocks. |
ysr@1580 | 612 | // Note that the BOT has not yet been updated for this block. |
ysr@1580 | 613 | size_t newFcSize = pointer_delta(value, prevEnd); |
ysr@1580 | 614 | // XXX This is REALLY UGLY and should be fixed up. XXX |
ysr@1580 | 615 | if (!_adaptive_freelists && _smallLinearAllocBlock._ptr == NULL) { |
ysr@1580 | 616 | // Mark the boundary of the new block in BOT |
ysr@1580 | 617 | _bt.mark_block(prevEnd, value); |
ysr@1580 | 618 | // put it all in the linAB |
ysr@1580 | 619 | if (ParallelGCThreads == 0) { |
ysr@1580 | 620 | _smallLinearAllocBlock._ptr = prevEnd; |
ysr@1580 | 621 | _smallLinearAllocBlock._word_size = newFcSize; |
ysr@1580 | 622 | repairLinearAllocBlock(&_smallLinearAllocBlock); |
ysr@1580 | 623 | } else { // ParallelGCThreads > 0 |
ysr@1580 | 624 | MutexLockerEx x(parDictionaryAllocLock(), |
ysr@1580 | 625 | Mutex::_no_safepoint_check_flag); |
ysr@1580 | 626 | _smallLinearAllocBlock._ptr = prevEnd; |
ysr@1580 | 627 | _smallLinearAllocBlock._word_size = newFcSize; |
ysr@1580 | 628 | repairLinearAllocBlock(&_smallLinearAllocBlock); |
ysr@1580 | 629 | } |
ysr@1580 | 630 | // Births of chunks put into a LinAB are not recorded. Births |
ysr@1580 | 631 | // of chunks as they are allocated out of a LinAB are. |
ysr@1580 | 632 | } else { |
ysr@1580 | 633 | // Add the block to the free lists, if possible coalescing it |
ysr@1580 | 634 | // with the last free block, and update the BOT and census data. |
ysr@1580 | 635 | addChunkToFreeListsAtEndRecordingStats(prevEnd, newFcSize); |
duke@435 | 636 | } |
duke@435 | 637 | } |
duke@435 | 638 | } |
duke@435 | 639 | } |
duke@435 | 640 | |
duke@435 | 641 | class FreeListSpace_DCTOC : public Filtering_DCTOC { |
duke@435 | 642 | CompactibleFreeListSpace* _cfls; |
duke@435 | 643 | CMSCollector* _collector; |
duke@435 | 644 | protected: |
duke@435 | 645 | // Override. |
duke@435 | 646 | #define walk_mem_region_with_cl_DECL(ClosureType) \ |
duke@435 | 647 | virtual void walk_mem_region_with_cl(MemRegion mr, \ |
duke@435 | 648 | HeapWord* bottom, HeapWord* top, \ |
duke@435 | 649 | ClosureType* cl); \ |
duke@435 | 650 | void walk_mem_region_with_cl_par(MemRegion mr, \ |
duke@435 | 651 | HeapWord* bottom, HeapWord* top, \ |
duke@435 | 652 | ClosureType* cl); \ |
duke@435 | 653 | void walk_mem_region_with_cl_nopar(MemRegion mr, \ |
duke@435 | 654 | HeapWord* bottom, HeapWord* top, \ |
duke@435 | 655 | ClosureType* cl) |
duke@435 | 656 | walk_mem_region_with_cl_DECL(OopClosure); |
duke@435 | 657 | walk_mem_region_with_cl_DECL(FilteringClosure); |
duke@435 | 658 | |
duke@435 | 659 | public: |
duke@435 | 660 | FreeListSpace_DCTOC(CompactibleFreeListSpace* sp, |
duke@435 | 661 | CMSCollector* collector, |
duke@435 | 662 | OopClosure* cl, |
duke@435 | 663 | CardTableModRefBS::PrecisionStyle precision, |
duke@435 | 664 | HeapWord* boundary) : |
duke@435 | 665 | Filtering_DCTOC(sp, cl, precision, boundary), |
duke@435 | 666 | _cfls(sp), _collector(collector) {} |
duke@435 | 667 | }; |
duke@435 | 668 | |
duke@435 | 669 | // We de-virtualize the block-related calls below, since we know that our |
duke@435 | 670 | // space is a CompactibleFreeListSpace. |
jmasa@3294 | 671 | |
duke@435 | 672 | #define FreeListSpace_DCTOC__walk_mem_region_with_cl_DEFN(ClosureType) \ |
duke@435 | 673 | void FreeListSpace_DCTOC::walk_mem_region_with_cl(MemRegion mr, \ |
duke@435 | 674 | HeapWord* bottom, \ |
duke@435 | 675 | HeapWord* top, \ |
duke@435 | 676 | ClosureType* cl) { \ |
jmasa@3294 | 677 | bool is_par = SharedHeap::heap()->n_par_threads() > 0; \ |
jmasa@3294 | 678 | if (is_par) { \ |
jmasa@3294 | 679 | assert(SharedHeap::heap()->n_par_threads() == \ |
jmasa@3294 | 680 | SharedHeap::heap()->workers()->active_workers(), "Mismatch"); \ |
duke@435 | 681 | walk_mem_region_with_cl_par(mr, bottom, top, cl); \ |
duke@435 | 682 | } else { \ |
duke@435 | 683 | walk_mem_region_with_cl_nopar(mr, bottom, top, cl); \ |
duke@435 | 684 | } \ |
duke@435 | 685 | } \ |
duke@435 | 686 | void FreeListSpace_DCTOC::walk_mem_region_with_cl_par(MemRegion mr, \ |
duke@435 | 687 | HeapWord* bottom, \ |
duke@435 | 688 | HeapWord* top, \ |
duke@435 | 689 | ClosureType* cl) { \ |
duke@435 | 690 | /* Skip parts that are before "mr", in case "block_start" sent us \ |
duke@435 | 691 | back too far. */ \ |
duke@435 | 692 | HeapWord* mr_start = mr.start(); \ |
duke@435 | 693 | size_t bot_size = _cfls->CompactibleFreeListSpace::block_size(bottom); \ |
duke@435 | 694 | HeapWord* next = bottom + bot_size; \ |
duke@435 | 695 | while (next < mr_start) { \ |
duke@435 | 696 | bottom = next; \ |
duke@435 | 697 | bot_size = _cfls->CompactibleFreeListSpace::block_size(bottom); \ |
duke@435 | 698 | next = bottom + bot_size; \ |
duke@435 | 699 | } \ |
duke@435 | 700 | \ |
duke@435 | 701 | while (bottom < top) { \ |
duke@435 | 702 | if (_cfls->CompactibleFreeListSpace::block_is_obj(bottom) && \ |
duke@435 | 703 | !_cfls->CompactibleFreeListSpace::obj_allocated_since_save_marks( \ |
duke@435 | 704 | oop(bottom)) && \ |
duke@435 | 705 | !_collector->CMSCollector::is_dead_obj(oop(bottom))) { \ |
duke@435 | 706 | size_t word_sz = oop(bottom)->oop_iterate(cl, mr); \ |
duke@435 | 707 | bottom += _cfls->adjustObjectSize(word_sz); \ |
duke@435 | 708 | } else { \ |
duke@435 | 709 | bottom += _cfls->CompactibleFreeListSpace::block_size(bottom); \ |
duke@435 | 710 | } \ |
duke@435 | 711 | } \ |
duke@435 | 712 | } \ |
duke@435 | 713 | void FreeListSpace_DCTOC::walk_mem_region_with_cl_nopar(MemRegion mr, \ |
duke@435 | 714 | HeapWord* bottom, \ |
duke@435 | 715 | HeapWord* top, \ |
duke@435 | 716 | ClosureType* cl) { \ |
duke@435 | 717 | /* Skip parts that are before "mr", in case "block_start" sent us \ |
duke@435 | 718 | back too far. */ \ |
duke@435 | 719 | HeapWord* mr_start = mr.start(); \ |
duke@435 | 720 | size_t bot_size = _cfls->CompactibleFreeListSpace::block_size_nopar(bottom); \ |
duke@435 | 721 | HeapWord* next = bottom + bot_size; \ |
duke@435 | 722 | while (next < mr_start) { \ |
duke@435 | 723 | bottom = next; \ |
duke@435 | 724 | bot_size = _cfls->CompactibleFreeListSpace::block_size_nopar(bottom); \ |
duke@435 | 725 | next = bottom + bot_size; \ |
duke@435 | 726 | } \ |
duke@435 | 727 | \ |
duke@435 | 728 | while (bottom < top) { \ |
duke@435 | 729 | if (_cfls->CompactibleFreeListSpace::block_is_obj_nopar(bottom) && \ |
duke@435 | 730 | !_cfls->CompactibleFreeListSpace::obj_allocated_since_save_marks( \ |
duke@435 | 731 | oop(bottom)) && \ |
duke@435 | 732 | !_collector->CMSCollector::is_dead_obj(oop(bottom))) { \ |
duke@435 | 733 | size_t word_sz = oop(bottom)->oop_iterate(cl, mr); \ |
duke@435 | 734 | bottom += _cfls->adjustObjectSize(word_sz); \ |
duke@435 | 735 | } else { \ |
duke@435 | 736 | bottom += _cfls->CompactibleFreeListSpace::block_size_nopar(bottom); \ |
duke@435 | 737 | } \ |
duke@435 | 738 | } \ |
duke@435 | 739 | } |
duke@435 | 740 | |
duke@435 | 741 | // (There are only two of these, rather than N, because the split is due |
duke@435 | 742 | // only to the introduction of the FilteringClosure, a local part of the |
duke@435 | 743 | // impl of this abstraction.) |
duke@435 | 744 | FreeListSpace_DCTOC__walk_mem_region_with_cl_DEFN(OopClosure) |
duke@435 | 745 | FreeListSpace_DCTOC__walk_mem_region_with_cl_DEFN(FilteringClosure) |
duke@435 | 746 | |
duke@435 | 747 | DirtyCardToOopClosure* |
duke@435 | 748 | CompactibleFreeListSpace::new_dcto_cl(OopClosure* cl, |
duke@435 | 749 | CardTableModRefBS::PrecisionStyle precision, |
duke@435 | 750 | HeapWord* boundary) { |
duke@435 | 751 | return new FreeListSpace_DCTOC(this, _collector, cl, precision, boundary); |
duke@435 | 752 | } |
duke@435 | 753 | |
duke@435 | 754 | |
duke@435 | 755 | // Note on locking for the space iteration functions: |
duke@435 | 756 | // since the collector's iteration activities are concurrent with |
duke@435 | 757 | // allocation activities by mutators, absent a suitable mutual exclusion |
duke@435 | 758 | // mechanism the iterators may go awry. For instace a block being iterated |
duke@435 | 759 | // may suddenly be allocated or divided up and part of it allocated and |
duke@435 | 760 | // so on. |
duke@435 | 761 | |
duke@435 | 762 | // Apply the given closure to each block in the space. |
duke@435 | 763 | void CompactibleFreeListSpace::blk_iterate_careful(BlkClosureCareful* cl) { |
duke@435 | 764 | assert_lock_strong(freelistLock()); |
duke@435 | 765 | HeapWord *cur, *limit; |
duke@435 | 766 | for (cur = bottom(), limit = end(); cur < limit; |
duke@435 | 767 | cur += cl->do_blk_careful(cur)); |
duke@435 | 768 | } |
duke@435 | 769 | |
duke@435 | 770 | // Apply the given closure to each block in the space. |
duke@435 | 771 | void CompactibleFreeListSpace::blk_iterate(BlkClosure* cl) { |
duke@435 | 772 | assert_lock_strong(freelistLock()); |
duke@435 | 773 | HeapWord *cur, *limit; |
duke@435 | 774 | for (cur = bottom(), limit = end(); cur < limit; |
duke@435 | 775 | cur += cl->do_blk(cur)); |
duke@435 | 776 | } |
duke@435 | 777 | |
duke@435 | 778 | // Apply the given closure to each oop in the space. |
duke@435 | 779 | void CompactibleFreeListSpace::oop_iterate(OopClosure* cl) { |
duke@435 | 780 | assert_lock_strong(freelistLock()); |
duke@435 | 781 | HeapWord *cur, *limit; |
duke@435 | 782 | size_t curSize; |
duke@435 | 783 | for (cur = bottom(), limit = end(); cur < limit; |
duke@435 | 784 | cur += curSize) { |
duke@435 | 785 | curSize = block_size(cur); |
duke@435 | 786 | if (block_is_obj(cur)) { |
duke@435 | 787 | oop(cur)->oop_iterate(cl); |
duke@435 | 788 | } |
duke@435 | 789 | } |
duke@435 | 790 | } |
duke@435 | 791 | |
duke@435 | 792 | // Apply the given closure to each oop in the space \intersect memory region. |
duke@435 | 793 | void CompactibleFreeListSpace::oop_iterate(MemRegion mr, OopClosure* cl) { |
duke@435 | 794 | assert_lock_strong(freelistLock()); |
duke@435 | 795 | if (is_empty()) { |
duke@435 | 796 | return; |
duke@435 | 797 | } |
duke@435 | 798 | MemRegion cur = MemRegion(bottom(), end()); |
duke@435 | 799 | mr = mr.intersection(cur); |
duke@435 | 800 | if (mr.is_empty()) { |
duke@435 | 801 | return; |
duke@435 | 802 | } |
duke@435 | 803 | if (mr.equals(cur)) { |
duke@435 | 804 | oop_iterate(cl); |
duke@435 | 805 | return; |
duke@435 | 806 | } |
duke@435 | 807 | assert(mr.end() <= end(), "just took an intersection above"); |
duke@435 | 808 | HeapWord* obj_addr = block_start(mr.start()); |
duke@435 | 809 | HeapWord* t = mr.end(); |
duke@435 | 810 | |
duke@435 | 811 | SpaceMemRegionOopsIterClosure smr_blk(cl, mr); |
duke@435 | 812 | if (block_is_obj(obj_addr)) { |
duke@435 | 813 | // Handle first object specially. |
duke@435 | 814 | oop obj = oop(obj_addr); |
duke@435 | 815 | obj_addr += adjustObjectSize(obj->oop_iterate(&smr_blk)); |
duke@435 | 816 | } else { |
duke@435 | 817 | FreeChunk* fc = (FreeChunk*)obj_addr; |
duke@435 | 818 | obj_addr += fc->size(); |
duke@435 | 819 | } |
duke@435 | 820 | while (obj_addr < t) { |
duke@435 | 821 | HeapWord* obj = obj_addr; |
duke@435 | 822 | obj_addr += block_size(obj_addr); |
duke@435 | 823 | // If "obj_addr" is not greater than top, then the |
duke@435 | 824 | // entire object "obj" is within the region. |
duke@435 | 825 | if (obj_addr <= t) { |
duke@435 | 826 | if (block_is_obj(obj)) { |
duke@435 | 827 | oop(obj)->oop_iterate(cl); |
duke@435 | 828 | } |
duke@435 | 829 | } else { |
duke@435 | 830 | // "obj" extends beyond end of region |
duke@435 | 831 | if (block_is_obj(obj)) { |
duke@435 | 832 | oop(obj)->oop_iterate(&smr_blk); |
duke@435 | 833 | } |
duke@435 | 834 | break; |
duke@435 | 835 | } |
duke@435 | 836 | } |
duke@435 | 837 | } |
duke@435 | 838 | |
duke@435 | 839 | // NOTE: In the following methods, in order to safely be able to |
duke@435 | 840 | // apply the closure to an object, we need to be sure that the |
duke@435 | 841 | // object has been initialized. We are guaranteed that an object |
duke@435 | 842 | // is initialized if we are holding the Heap_lock with the |
duke@435 | 843 | // world stopped. |
duke@435 | 844 | void CompactibleFreeListSpace::verify_objects_initialized() const { |
duke@435 | 845 | if (is_init_completed()) { |
duke@435 | 846 | assert_locked_or_safepoint(Heap_lock); |
duke@435 | 847 | if (Universe::is_fully_initialized()) { |
duke@435 | 848 | guarantee(SafepointSynchronize::is_at_safepoint(), |
duke@435 | 849 | "Required for objects to be initialized"); |
duke@435 | 850 | } |
duke@435 | 851 | } // else make a concession at vm start-up |
duke@435 | 852 | } |
duke@435 | 853 | |
duke@435 | 854 | // Apply the given closure to each object in the space |
duke@435 | 855 | void CompactibleFreeListSpace::object_iterate(ObjectClosure* blk) { |
duke@435 | 856 | assert_lock_strong(freelistLock()); |
duke@435 | 857 | NOT_PRODUCT(verify_objects_initialized()); |
duke@435 | 858 | HeapWord *cur, *limit; |
duke@435 | 859 | size_t curSize; |
duke@435 | 860 | for (cur = bottom(), limit = end(); cur < limit; |
duke@435 | 861 | cur += curSize) { |
duke@435 | 862 | curSize = block_size(cur); |
duke@435 | 863 | if (block_is_obj(cur)) { |
duke@435 | 864 | blk->do_object(oop(cur)); |
duke@435 | 865 | } |
duke@435 | 866 | } |
duke@435 | 867 | } |
duke@435 | 868 | |
jmasa@952 | 869 | // Apply the given closure to each live object in the space |
jmasa@952 | 870 | // The usage of CompactibleFreeListSpace |
jmasa@952 | 871 | // by the ConcurrentMarkSweepGeneration for concurrent GC's allows |
jmasa@952 | 872 | // objects in the space with references to objects that are no longer |
jmasa@952 | 873 | // valid. For example, an object may reference another object |
jmasa@952 | 874 | // that has already been sweep up (collected). This method uses |
jmasa@952 | 875 | // obj_is_alive() to determine whether it is safe to apply the closure to |
jmasa@952 | 876 | // an object. See obj_is_alive() for details on how liveness of an |
jmasa@952 | 877 | // object is decided. |
jmasa@952 | 878 | |
jmasa@952 | 879 | void CompactibleFreeListSpace::safe_object_iterate(ObjectClosure* blk) { |
jmasa@952 | 880 | assert_lock_strong(freelistLock()); |
jmasa@952 | 881 | NOT_PRODUCT(verify_objects_initialized()); |
jmasa@952 | 882 | HeapWord *cur, *limit; |
jmasa@952 | 883 | size_t curSize; |
jmasa@952 | 884 | for (cur = bottom(), limit = end(); cur < limit; |
jmasa@952 | 885 | cur += curSize) { |
jmasa@952 | 886 | curSize = block_size(cur); |
jmasa@952 | 887 | if (block_is_obj(cur) && obj_is_alive(cur)) { |
jmasa@952 | 888 | blk->do_object(oop(cur)); |
jmasa@952 | 889 | } |
jmasa@952 | 890 | } |
jmasa@952 | 891 | } |
jmasa@952 | 892 | |
duke@435 | 893 | void CompactibleFreeListSpace::object_iterate_mem(MemRegion mr, |
duke@435 | 894 | UpwardsObjectClosure* cl) { |
ysr@1580 | 895 | assert_locked(freelistLock()); |
duke@435 | 896 | NOT_PRODUCT(verify_objects_initialized()); |
duke@435 | 897 | Space::object_iterate_mem(mr, cl); |
duke@435 | 898 | } |
duke@435 | 899 | |
duke@435 | 900 | // Callers of this iterator beware: The closure application should |
duke@435 | 901 | // be robust in the face of uninitialized objects and should (always) |
duke@435 | 902 | // return a correct size so that the next addr + size below gives us a |
duke@435 | 903 | // valid block boundary. [See for instance, |
duke@435 | 904 | // ScanMarkedObjectsAgainCarefullyClosure::do_object_careful() |
duke@435 | 905 | // in ConcurrentMarkSweepGeneration.cpp.] |
duke@435 | 906 | HeapWord* |
duke@435 | 907 | CompactibleFreeListSpace::object_iterate_careful(ObjectClosureCareful* cl) { |
duke@435 | 908 | assert_lock_strong(freelistLock()); |
duke@435 | 909 | HeapWord *addr, *last; |
duke@435 | 910 | size_t size; |
duke@435 | 911 | for (addr = bottom(), last = end(); |
duke@435 | 912 | addr < last; addr += size) { |
duke@435 | 913 | FreeChunk* fc = (FreeChunk*)addr; |
duke@435 | 914 | if (fc->isFree()) { |
duke@435 | 915 | // Since we hold the free list lock, which protects direct |
duke@435 | 916 | // allocation in this generation by mutators, a free object |
duke@435 | 917 | // will remain free throughout this iteration code. |
duke@435 | 918 | size = fc->size(); |
duke@435 | 919 | } else { |
duke@435 | 920 | // Note that the object need not necessarily be initialized, |
duke@435 | 921 | // because (for instance) the free list lock does NOT protect |
duke@435 | 922 | // object initialization. The closure application below must |
duke@435 | 923 | // therefore be correct in the face of uninitialized objects. |
duke@435 | 924 | size = cl->do_object_careful(oop(addr)); |
duke@435 | 925 | if (size == 0) { |
duke@435 | 926 | // An unparsable object found. Signal early termination. |
duke@435 | 927 | return addr; |
duke@435 | 928 | } |
duke@435 | 929 | } |
duke@435 | 930 | } |
duke@435 | 931 | return NULL; |
duke@435 | 932 | } |
duke@435 | 933 | |
duke@435 | 934 | // Callers of this iterator beware: The closure application should |
duke@435 | 935 | // be robust in the face of uninitialized objects and should (always) |
duke@435 | 936 | // return a correct size so that the next addr + size below gives us a |
duke@435 | 937 | // valid block boundary. [See for instance, |
duke@435 | 938 | // ScanMarkedObjectsAgainCarefullyClosure::do_object_careful() |
duke@435 | 939 | // in ConcurrentMarkSweepGeneration.cpp.] |
duke@435 | 940 | HeapWord* |
duke@435 | 941 | CompactibleFreeListSpace::object_iterate_careful_m(MemRegion mr, |
duke@435 | 942 | ObjectClosureCareful* cl) { |
duke@435 | 943 | assert_lock_strong(freelistLock()); |
duke@435 | 944 | // Can't use used_region() below because it may not necessarily |
duke@435 | 945 | // be the same as [bottom(),end()); although we could |
duke@435 | 946 | // use [used_region().start(),round_to(used_region().end(),CardSize)), |
duke@435 | 947 | // that appears too cumbersome, so we just do the simpler check |
duke@435 | 948 | // in the assertion below. |
duke@435 | 949 | assert(!mr.is_empty() && MemRegion(bottom(),end()).contains(mr), |
duke@435 | 950 | "mr should be non-empty and within used space"); |
duke@435 | 951 | HeapWord *addr, *end; |
duke@435 | 952 | size_t size; |
duke@435 | 953 | for (addr = block_start_careful(mr.start()), end = mr.end(); |
duke@435 | 954 | addr < end; addr += size) { |
duke@435 | 955 | FreeChunk* fc = (FreeChunk*)addr; |
duke@435 | 956 | if (fc->isFree()) { |
duke@435 | 957 | // Since we hold the free list lock, which protects direct |
duke@435 | 958 | // allocation in this generation by mutators, a free object |
duke@435 | 959 | // will remain free throughout this iteration code. |
duke@435 | 960 | size = fc->size(); |
duke@435 | 961 | } else { |
duke@435 | 962 | // Note that the object need not necessarily be initialized, |
duke@435 | 963 | // because (for instance) the free list lock does NOT protect |
duke@435 | 964 | // object initialization. The closure application below must |
duke@435 | 965 | // therefore be correct in the face of uninitialized objects. |
duke@435 | 966 | size = cl->do_object_careful_m(oop(addr), mr); |
duke@435 | 967 | if (size == 0) { |
duke@435 | 968 | // An unparsable object found. Signal early termination. |
duke@435 | 969 | return addr; |
duke@435 | 970 | } |
duke@435 | 971 | } |
duke@435 | 972 | } |
duke@435 | 973 | return NULL; |
duke@435 | 974 | } |
duke@435 | 975 | |
duke@435 | 976 | |
ysr@777 | 977 | HeapWord* CompactibleFreeListSpace::block_start_const(const void* p) const { |
duke@435 | 978 | NOT_PRODUCT(verify_objects_initialized()); |
duke@435 | 979 | return _bt.block_start(p); |
duke@435 | 980 | } |
duke@435 | 981 | |
duke@435 | 982 | HeapWord* CompactibleFreeListSpace::block_start_careful(const void* p) const { |
duke@435 | 983 | return _bt.block_start_careful(p); |
duke@435 | 984 | } |
duke@435 | 985 | |
duke@435 | 986 | size_t CompactibleFreeListSpace::block_size(const HeapWord* p) const { |
duke@435 | 987 | NOT_PRODUCT(verify_objects_initialized()); |
duke@435 | 988 | // This must be volatile, or else there is a danger that the compiler |
duke@435 | 989 | // will compile the code below into a sometimes-infinite loop, by keeping |
duke@435 | 990 | // the value read the first time in a register. |
duke@435 | 991 | while (true) { |
duke@435 | 992 | // We must do this until we get a consistent view of the object. |
coleenp@622 | 993 | if (FreeChunk::indicatesFreeChunk(p)) { |
coleenp@622 | 994 | volatile FreeChunk* fc = (volatile FreeChunk*)p; |
coleenp@622 | 995 | size_t res = fc->size(); |
coleenp@622 | 996 | // If the object is still a free chunk, return the size, else it |
coleenp@622 | 997 | // has been allocated so try again. |
coleenp@622 | 998 | if (FreeChunk::indicatesFreeChunk(p)) { |
duke@435 | 999 | assert(res != 0, "Block size should not be 0"); |
duke@435 | 1000 | return res; |
duke@435 | 1001 | } |
coleenp@622 | 1002 | } else { |
coleenp@622 | 1003 | // must read from what 'p' points to in each loop. |
coleenp@622 | 1004 | klassOop k = ((volatile oopDesc*)p)->klass_or_null(); |
coleenp@622 | 1005 | if (k != NULL) { |
ysr@2071 | 1006 | assert(k->is_oop(true /* ignore mark word */), "Should be klass oop"); |
coleenp@622 | 1007 | oop o = (oop)p; |
coleenp@622 | 1008 | assert(o->is_parsable(), "Should be parsable"); |
coleenp@622 | 1009 | assert(o->is_oop(true /* ignore mark word */), "Should be an oop."); |
coleenp@622 | 1010 | size_t res = o->size_given_klass(k->klass_part()); |
coleenp@622 | 1011 | res = adjustObjectSize(res); |
coleenp@622 | 1012 | assert(res != 0, "Block size should not be 0"); |
coleenp@622 | 1013 | return res; |
coleenp@622 | 1014 | } |
duke@435 | 1015 | } |
duke@435 | 1016 | } |
duke@435 | 1017 | } |
duke@435 | 1018 | |
duke@435 | 1019 | // A variant of the above that uses the Printezis bits for |
duke@435 | 1020 | // unparsable but allocated objects. This avoids any possible |
duke@435 | 1021 | // stalls waiting for mutators to initialize objects, and is |
duke@435 | 1022 | // thus potentially faster than the variant above. However, |
duke@435 | 1023 | // this variant may return a zero size for a block that is |
duke@435 | 1024 | // under mutation and for which a consistent size cannot be |
duke@435 | 1025 | // inferred without stalling; see CMSCollector::block_size_if_printezis_bits(). |
duke@435 | 1026 | size_t CompactibleFreeListSpace::block_size_no_stall(HeapWord* p, |
duke@435 | 1027 | const CMSCollector* c) |
duke@435 | 1028 | const { |
duke@435 | 1029 | assert(MemRegion(bottom(), end()).contains(p), "p not in space"); |
duke@435 | 1030 | // This must be volatile, or else there is a danger that the compiler |
duke@435 | 1031 | // will compile the code below into a sometimes-infinite loop, by keeping |
duke@435 | 1032 | // the value read the first time in a register. |
duke@435 | 1033 | DEBUG_ONLY(uint loops = 0;) |
duke@435 | 1034 | while (true) { |
duke@435 | 1035 | // We must do this until we get a consistent view of the object. |
coleenp@622 | 1036 | if (FreeChunk::indicatesFreeChunk(p)) { |
coleenp@622 | 1037 | volatile FreeChunk* fc = (volatile FreeChunk*)p; |
coleenp@622 | 1038 | size_t res = fc->size(); |
coleenp@622 | 1039 | if (FreeChunk::indicatesFreeChunk(p)) { |
duke@435 | 1040 | assert(res != 0, "Block size should not be 0"); |
duke@435 | 1041 | assert(loops == 0, "Should be 0"); |
duke@435 | 1042 | return res; |
duke@435 | 1043 | } |
duke@435 | 1044 | } else { |
coleenp@622 | 1045 | // must read from what 'p' points to in each loop. |
coleenp@622 | 1046 | klassOop k = ((volatile oopDesc*)p)->klass_or_null(); |
ysr@2533 | 1047 | // We trust the size of any object that has a non-NULL |
ysr@2533 | 1048 | // klass and (for those in the perm gen) is parsable |
ysr@2533 | 1049 | // -- irrespective of its conc_safe-ty. |
ysr@2533 | 1050 | if (k != NULL && ((oopDesc*)p)->is_parsable()) { |
coleenp@622 | 1051 | assert(k->is_oop(), "Should really be klass oop."); |
coleenp@622 | 1052 | oop o = (oop)p; |
coleenp@622 | 1053 | assert(o->is_oop(), "Should be an oop"); |
coleenp@622 | 1054 | size_t res = o->size_given_klass(k->klass_part()); |
coleenp@622 | 1055 | res = adjustObjectSize(res); |
coleenp@622 | 1056 | assert(res != 0, "Block size should not be 0"); |
coleenp@622 | 1057 | return res; |
coleenp@622 | 1058 | } else { |
ysr@2533 | 1059 | // May return 0 if P-bits not present. |
coleenp@622 | 1060 | return c->block_size_if_printezis_bits(p); |
coleenp@622 | 1061 | } |
duke@435 | 1062 | } |
duke@435 | 1063 | assert(loops == 0, "Can loop at most once"); |
duke@435 | 1064 | DEBUG_ONLY(loops++;) |
duke@435 | 1065 | } |
duke@435 | 1066 | } |
duke@435 | 1067 | |
duke@435 | 1068 | size_t CompactibleFreeListSpace::block_size_nopar(const HeapWord* p) const { |
duke@435 | 1069 | NOT_PRODUCT(verify_objects_initialized()); |
duke@435 | 1070 | assert(MemRegion(bottom(), end()).contains(p), "p not in space"); |
duke@435 | 1071 | FreeChunk* fc = (FreeChunk*)p; |
duke@435 | 1072 | if (fc->isFree()) { |
duke@435 | 1073 | return fc->size(); |
duke@435 | 1074 | } else { |
duke@435 | 1075 | // Ignore mark word because this may be a recently promoted |
duke@435 | 1076 | // object whose mark word is used to chain together grey |
duke@435 | 1077 | // objects (the last one would have a null value). |
duke@435 | 1078 | assert(oop(p)->is_oop(true), "Should be an oop"); |
duke@435 | 1079 | return adjustObjectSize(oop(p)->size()); |
duke@435 | 1080 | } |
duke@435 | 1081 | } |
duke@435 | 1082 | |
duke@435 | 1083 | // This implementation assumes that the property of "being an object" is |
duke@435 | 1084 | // stable. But being a free chunk may not be (because of parallel |
duke@435 | 1085 | // promotion.) |
duke@435 | 1086 | bool CompactibleFreeListSpace::block_is_obj(const HeapWord* p) const { |
duke@435 | 1087 | FreeChunk* fc = (FreeChunk*)p; |
duke@435 | 1088 | assert(is_in_reserved(p), "Should be in space"); |
duke@435 | 1089 | // When doing a mark-sweep-compact of the CMS generation, this |
duke@435 | 1090 | // assertion may fail because prepare_for_compaction() uses |
duke@435 | 1091 | // space that is garbage to maintain information on ranges of |
duke@435 | 1092 | // live objects so that these live ranges can be moved as a whole. |
duke@435 | 1093 | // Comment out this assertion until that problem can be solved |
duke@435 | 1094 | // (i.e., that the block start calculation may look at objects |
duke@435 | 1095 | // at address below "p" in finding the object that contains "p" |
duke@435 | 1096 | // and those objects (if garbage) may have been modified to hold |
duke@435 | 1097 | // live range information. |
jmasa@2188 | 1098 | // assert(CollectedHeap::use_parallel_gc_threads() || _bt.block_start(p) == p, |
jmasa@2188 | 1099 | // "Should be a block boundary"); |
coleenp@622 | 1100 | if (FreeChunk::indicatesFreeChunk(p)) return false; |
coleenp@622 | 1101 | klassOop k = oop(p)->klass_or_null(); |
duke@435 | 1102 | if (k != NULL) { |
duke@435 | 1103 | // Ignore mark word because it may have been used to |
duke@435 | 1104 | // chain together promoted objects (the last one |
duke@435 | 1105 | // would have a null value). |
duke@435 | 1106 | assert(oop(p)->is_oop(true), "Should be an oop"); |
duke@435 | 1107 | return true; |
duke@435 | 1108 | } else { |
duke@435 | 1109 | return false; // Was not an object at the start of collection. |
duke@435 | 1110 | } |
duke@435 | 1111 | } |
duke@435 | 1112 | |
duke@435 | 1113 | // Check if the object is alive. This fact is checked either by consulting |
duke@435 | 1114 | // the main marking bitmap in the sweeping phase or, if it's a permanent |
duke@435 | 1115 | // generation and we're not in the sweeping phase, by checking the |
duke@435 | 1116 | // perm_gen_verify_bit_map where we store the "deadness" information if |
duke@435 | 1117 | // we did not sweep the perm gen in the most recent previous GC cycle. |
duke@435 | 1118 | bool CompactibleFreeListSpace::obj_is_alive(const HeapWord* p) const { |
ysr@2301 | 1119 | assert(SafepointSynchronize::is_at_safepoint() || !is_init_completed(), |
ysr@2301 | 1120 | "Else races are possible"); |
ysr@2293 | 1121 | assert(block_is_obj(p), "The address should point to an object"); |
duke@435 | 1122 | |
duke@435 | 1123 | // If we're sweeping, we use object liveness information from the main bit map |
duke@435 | 1124 | // for both perm gen and old gen. |
duke@435 | 1125 | // We don't need to lock the bitmap (live_map or dead_map below), because |
duke@435 | 1126 | // EITHER we are in the middle of the sweeping phase, and the |
duke@435 | 1127 | // main marking bit map (live_map below) is locked, |
duke@435 | 1128 | // OR we're in other phases and perm_gen_verify_bit_map (dead_map below) |
duke@435 | 1129 | // is stable, because it's mutated only in the sweeping phase. |
ysr@2293 | 1130 | // NOTE: This method is also used by jmap where, if class unloading is |
ysr@2293 | 1131 | // off, the results can return "false" for legitimate perm objects, |
ysr@2293 | 1132 | // when we are not in the midst of a sweeping phase, which can result |
ysr@2293 | 1133 | // in jmap not reporting certain perm gen objects. This will be moot |
ysr@2293 | 1134 | // if/when the perm gen goes away in the future. |
duke@435 | 1135 | if (_collector->abstract_state() == CMSCollector::Sweeping) { |
duke@435 | 1136 | CMSBitMap* live_map = _collector->markBitMap(); |
ysr@2293 | 1137 | return live_map->par_isMarked((HeapWord*) p); |
duke@435 | 1138 | } else { |
duke@435 | 1139 | // If we're not currently sweeping and we haven't swept the perm gen in |
duke@435 | 1140 | // the previous concurrent cycle then we may have dead but unswept objects |
duke@435 | 1141 | // in the perm gen. In this case, we use the "deadness" information |
duke@435 | 1142 | // that we had saved in perm_gen_verify_bit_map at the last sweep. |
duke@435 | 1143 | if (!CMSClassUnloadingEnabled && _collector->_permGen->reserved().contains(p)) { |
duke@435 | 1144 | if (_collector->verifying()) { |
duke@435 | 1145 | CMSBitMap* dead_map = _collector->perm_gen_verify_bit_map(); |
duke@435 | 1146 | // Object is marked in the dead_map bitmap at the previous sweep |
duke@435 | 1147 | // when we know that it's dead; if the bitmap is not allocated then |
duke@435 | 1148 | // the object is alive. |
duke@435 | 1149 | return (dead_map->sizeInBits() == 0) // bit_map has been allocated |
duke@435 | 1150 | || !dead_map->par_isMarked((HeapWord*) p); |
duke@435 | 1151 | } else { |
duke@435 | 1152 | return false; // We can't say for sure if it's live, so we say that it's dead. |
duke@435 | 1153 | } |
duke@435 | 1154 | } |
duke@435 | 1155 | } |
duke@435 | 1156 | return true; |
duke@435 | 1157 | } |
duke@435 | 1158 | |
duke@435 | 1159 | bool CompactibleFreeListSpace::block_is_obj_nopar(const HeapWord* p) const { |
duke@435 | 1160 | FreeChunk* fc = (FreeChunk*)p; |
duke@435 | 1161 | assert(is_in_reserved(p), "Should be in space"); |
duke@435 | 1162 | assert(_bt.block_start(p) == p, "Should be a block boundary"); |
duke@435 | 1163 | if (!fc->isFree()) { |
duke@435 | 1164 | // Ignore mark word because it may have been used to |
duke@435 | 1165 | // chain together promoted objects (the last one |
duke@435 | 1166 | // would have a null value). |
duke@435 | 1167 | assert(oop(p)->is_oop(true), "Should be an oop"); |
duke@435 | 1168 | return true; |
duke@435 | 1169 | } |
duke@435 | 1170 | return false; |
duke@435 | 1171 | } |
duke@435 | 1172 | |
duke@435 | 1173 | // "MT-safe but not guaranteed MT-precise" (TM); you may get an |
duke@435 | 1174 | // approximate answer if you don't hold the freelistlock when you call this. |
duke@435 | 1175 | size_t CompactibleFreeListSpace::totalSizeInIndexedFreeLists() const { |
duke@435 | 1176 | size_t size = 0; |
duke@435 | 1177 | for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 1178 | debug_only( |
duke@435 | 1179 | // We may be calling here without the lock in which case we |
duke@435 | 1180 | // won't do this modest sanity check. |
duke@435 | 1181 | if (freelistLock()->owned_by_self()) { |
duke@435 | 1182 | size_t total_list_size = 0; |
duke@435 | 1183 | for (FreeChunk* fc = _indexedFreeList[i].head(); fc != NULL; |
duke@435 | 1184 | fc = fc->next()) { |
duke@435 | 1185 | total_list_size += i; |
duke@435 | 1186 | } |
duke@435 | 1187 | assert(total_list_size == i * _indexedFreeList[i].count(), |
duke@435 | 1188 | "Count in list is incorrect"); |
duke@435 | 1189 | } |
duke@435 | 1190 | ) |
duke@435 | 1191 | size += i * _indexedFreeList[i].count(); |
duke@435 | 1192 | } |
duke@435 | 1193 | return size; |
duke@435 | 1194 | } |
duke@435 | 1195 | |
duke@435 | 1196 | HeapWord* CompactibleFreeListSpace::par_allocate(size_t size) { |
duke@435 | 1197 | MutexLockerEx x(freelistLock(), Mutex::_no_safepoint_check_flag); |
duke@435 | 1198 | return allocate(size); |
duke@435 | 1199 | } |
duke@435 | 1200 | |
duke@435 | 1201 | HeapWord* |
duke@435 | 1202 | CompactibleFreeListSpace::getChunkFromSmallLinearAllocBlockRemainder(size_t size) { |
duke@435 | 1203 | return getChunkFromLinearAllocBlockRemainder(&_smallLinearAllocBlock, size); |
duke@435 | 1204 | } |
duke@435 | 1205 | |
duke@435 | 1206 | HeapWord* CompactibleFreeListSpace::allocate(size_t size) { |
duke@435 | 1207 | assert_lock_strong(freelistLock()); |
duke@435 | 1208 | HeapWord* res = NULL; |
duke@435 | 1209 | assert(size == adjustObjectSize(size), |
duke@435 | 1210 | "use adjustObjectSize() before calling into allocate()"); |
duke@435 | 1211 | |
duke@435 | 1212 | if (_adaptive_freelists) { |
duke@435 | 1213 | res = allocate_adaptive_freelists(size); |
duke@435 | 1214 | } else { // non-adaptive free lists |
duke@435 | 1215 | res = allocate_non_adaptive_freelists(size); |
duke@435 | 1216 | } |
duke@435 | 1217 | |
duke@435 | 1218 | if (res != NULL) { |
duke@435 | 1219 | // check that res does lie in this space! |
duke@435 | 1220 | assert(is_in_reserved(res), "Not in this space!"); |
duke@435 | 1221 | assert(is_aligned((void*)res), "alignment check"); |
duke@435 | 1222 | |
duke@435 | 1223 | FreeChunk* fc = (FreeChunk*)res; |
duke@435 | 1224 | fc->markNotFree(); |
duke@435 | 1225 | assert(!fc->isFree(), "shouldn't be marked free"); |
coleenp@622 | 1226 | assert(oop(fc)->klass_or_null() == NULL, "should look uninitialized"); |
duke@435 | 1227 | // Verify that the block offset table shows this to |
duke@435 | 1228 | // be a single block, but not one which is unallocated. |
duke@435 | 1229 | _bt.verify_single_block(res, size); |
duke@435 | 1230 | _bt.verify_not_unallocated(res, size); |
duke@435 | 1231 | // mangle a just allocated object with a distinct pattern. |
duke@435 | 1232 | debug_only(fc->mangleAllocated(size)); |
duke@435 | 1233 | } |
duke@435 | 1234 | |
duke@435 | 1235 | return res; |
duke@435 | 1236 | } |
duke@435 | 1237 | |
duke@435 | 1238 | HeapWord* CompactibleFreeListSpace::allocate_non_adaptive_freelists(size_t size) { |
duke@435 | 1239 | HeapWord* res = NULL; |
duke@435 | 1240 | // try and use linear allocation for smaller blocks |
duke@435 | 1241 | if (size < _smallLinearAllocBlock._allocation_size_limit) { |
duke@435 | 1242 | // if successful, the following also adjusts block offset table |
duke@435 | 1243 | res = getChunkFromSmallLinearAllocBlock(size); |
duke@435 | 1244 | } |
duke@435 | 1245 | // Else triage to indexed lists for smaller sizes |
duke@435 | 1246 | if (res == NULL) { |
duke@435 | 1247 | if (size < SmallForDictionary) { |
duke@435 | 1248 | res = (HeapWord*) getChunkFromIndexedFreeList(size); |
duke@435 | 1249 | } else { |
duke@435 | 1250 | // else get it from the big dictionary; if even this doesn't |
duke@435 | 1251 | // work we are out of luck. |
duke@435 | 1252 | res = (HeapWord*)getChunkFromDictionaryExact(size); |
duke@435 | 1253 | } |
duke@435 | 1254 | } |
duke@435 | 1255 | |
duke@435 | 1256 | return res; |
duke@435 | 1257 | } |
duke@435 | 1258 | |
duke@435 | 1259 | HeapWord* CompactibleFreeListSpace::allocate_adaptive_freelists(size_t size) { |
duke@435 | 1260 | assert_lock_strong(freelistLock()); |
duke@435 | 1261 | HeapWord* res = NULL; |
duke@435 | 1262 | assert(size == adjustObjectSize(size), |
duke@435 | 1263 | "use adjustObjectSize() before calling into allocate()"); |
duke@435 | 1264 | |
duke@435 | 1265 | // Strategy |
duke@435 | 1266 | // if small |
duke@435 | 1267 | // exact size from small object indexed list if small |
duke@435 | 1268 | // small or large linear allocation block (linAB) as appropriate |
duke@435 | 1269 | // take from lists of greater sized chunks |
duke@435 | 1270 | // else |
duke@435 | 1271 | // dictionary |
duke@435 | 1272 | // small or large linear allocation block if it has the space |
duke@435 | 1273 | // Try allocating exact size from indexTable first |
duke@435 | 1274 | if (size < IndexSetSize) { |
duke@435 | 1275 | res = (HeapWord*) getChunkFromIndexedFreeList(size); |
duke@435 | 1276 | if(res != NULL) { |
duke@435 | 1277 | assert(res != (HeapWord*)_indexedFreeList[size].head(), |
duke@435 | 1278 | "Not removed from free list"); |
duke@435 | 1279 | // no block offset table adjustment is necessary on blocks in |
duke@435 | 1280 | // the indexed lists. |
duke@435 | 1281 | |
duke@435 | 1282 | // Try allocating from the small LinAB |
duke@435 | 1283 | } else if (size < _smallLinearAllocBlock._allocation_size_limit && |
duke@435 | 1284 | (res = getChunkFromSmallLinearAllocBlock(size)) != NULL) { |
duke@435 | 1285 | // if successful, the above also adjusts block offset table |
duke@435 | 1286 | // Note that this call will refill the LinAB to |
duke@435 | 1287 | // satisfy the request. This is different that |
duke@435 | 1288 | // evm. |
duke@435 | 1289 | // Don't record chunk off a LinAB? smallSplitBirth(size); |
duke@435 | 1290 | } else { |
duke@435 | 1291 | // Raid the exact free lists larger than size, even if they are not |
duke@435 | 1292 | // overpopulated. |
duke@435 | 1293 | res = (HeapWord*) getChunkFromGreater(size); |
duke@435 | 1294 | } |
duke@435 | 1295 | } else { |
duke@435 | 1296 | // Big objects get allocated directly from the dictionary. |
duke@435 | 1297 | res = (HeapWord*) getChunkFromDictionaryExact(size); |
duke@435 | 1298 | if (res == NULL) { |
duke@435 | 1299 | // Try hard not to fail since an allocation failure will likely |
duke@435 | 1300 | // trigger a synchronous GC. Try to get the space from the |
duke@435 | 1301 | // allocation blocks. |
duke@435 | 1302 | res = getChunkFromSmallLinearAllocBlockRemainder(size); |
duke@435 | 1303 | } |
duke@435 | 1304 | } |
duke@435 | 1305 | |
duke@435 | 1306 | return res; |
duke@435 | 1307 | } |
duke@435 | 1308 | |
duke@435 | 1309 | // A worst-case estimate of the space required (in HeapWords) to expand the heap |
duke@435 | 1310 | // when promoting obj. |
duke@435 | 1311 | size_t CompactibleFreeListSpace::expansionSpaceRequired(size_t obj_size) const { |
duke@435 | 1312 | // Depending on the object size, expansion may require refilling either a |
duke@435 | 1313 | // bigLAB or a smallLAB plus refilling a PromotionInfo object. MinChunkSize |
duke@435 | 1314 | // is added because the dictionary may over-allocate to avoid fragmentation. |
duke@435 | 1315 | size_t space = obj_size; |
duke@435 | 1316 | if (!_adaptive_freelists) { |
duke@435 | 1317 | space = MAX2(space, _smallLinearAllocBlock._refillSize); |
duke@435 | 1318 | } |
duke@435 | 1319 | space += _promoInfo.refillSize() + 2 * MinChunkSize; |
duke@435 | 1320 | return space; |
duke@435 | 1321 | } |
duke@435 | 1322 | |
duke@435 | 1323 | FreeChunk* CompactibleFreeListSpace::getChunkFromGreater(size_t numWords) { |
duke@435 | 1324 | FreeChunk* ret; |
duke@435 | 1325 | |
duke@435 | 1326 | assert(numWords >= MinChunkSize, "Size is less than minimum"); |
duke@435 | 1327 | assert(linearAllocationWouldFail() || bestFitFirst(), |
duke@435 | 1328 | "Should not be here"); |
duke@435 | 1329 | |
duke@435 | 1330 | size_t i; |
duke@435 | 1331 | size_t currSize = numWords + MinChunkSize; |
duke@435 | 1332 | assert(currSize % MinObjAlignment == 0, "currSize should be aligned"); |
duke@435 | 1333 | for (i = currSize; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 1334 | FreeList* fl = &_indexedFreeList[i]; |
duke@435 | 1335 | if (fl->head()) { |
duke@435 | 1336 | ret = getFromListGreater(fl, numWords); |
duke@435 | 1337 | assert(ret == NULL || ret->isFree(), "Should be returning a free chunk"); |
duke@435 | 1338 | return ret; |
duke@435 | 1339 | } |
duke@435 | 1340 | } |
duke@435 | 1341 | |
duke@435 | 1342 | currSize = MAX2((size_t)SmallForDictionary, |
duke@435 | 1343 | (size_t)(numWords + MinChunkSize)); |
duke@435 | 1344 | |
duke@435 | 1345 | /* Try to get a chunk that satisfies request, while avoiding |
duke@435 | 1346 | fragmentation that can't be handled. */ |
duke@435 | 1347 | { |
duke@435 | 1348 | ret = dictionary()->getChunk(currSize); |
duke@435 | 1349 | if (ret != NULL) { |
duke@435 | 1350 | assert(ret->size() - numWords >= MinChunkSize, |
duke@435 | 1351 | "Chunk is too small"); |
duke@435 | 1352 | _bt.allocated((HeapWord*)ret, ret->size()); |
duke@435 | 1353 | /* Carve returned chunk. */ |
duke@435 | 1354 | (void) splitChunkAndReturnRemainder(ret, numWords); |
duke@435 | 1355 | /* Label this as no longer a free chunk. */ |
duke@435 | 1356 | assert(ret->isFree(), "This chunk should be free"); |
duke@435 | 1357 | ret->linkPrev(NULL); |
duke@435 | 1358 | } |
duke@435 | 1359 | assert(ret == NULL || ret->isFree(), "Should be returning a free chunk"); |
duke@435 | 1360 | return ret; |
duke@435 | 1361 | } |
duke@435 | 1362 | ShouldNotReachHere(); |
duke@435 | 1363 | } |
duke@435 | 1364 | |
ysr@3220 | 1365 | bool CompactibleFreeListSpace::verifyChunkInIndexedFreeLists(FreeChunk* fc) const { |
duke@435 | 1366 | assert(fc->size() < IndexSetSize, "Size of chunk is too large"); |
duke@435 | 1367 | return _indexedFreeList[fc->size()].verifyChunkInFreeLists(fc); |
duke@435 | 1368 | } |
duke@435 | 1369 | |
ysr@3220 | 1370 | bool CompactibleFreeListSpace::verify_chunk_is_linear_alloc_block(FreeChunk* fc) const { |
ysr@3220 | 1371 | assert((_smallLinearAllocBlock._ptr != (HeapWord*)fc) || |
ysr@3220 | 1372 | (_smallLinearAllocBlock._word_size == fc->size()), |
ysr@3220 | 1373 | "Linear allocation block shows incorrect size"); |
ysr@3220 | 1374 | return ((_smallLinearAllocBlock._ptr == (HeapWord*)fc) && |
ysr@3220 | 1375 | (_smallLinearAllocBlock._word_size == fc->size())); |
ysr@3220 | 1376 | } |
ysr@3220 | 1377 | |
ysr@3220 | 1378 | // Check if the purported free chunk is present either as a linear |
ysr@3220 | 1379 | // allocation block, the size-indexed table of (smaller) free blocks, |
ysr@3220 | 1380 | // or the larger free blocks kept in the binary tree dictionary. |
duke@435 | 1381 | bool CompactibleFreeListSpace::verifyChunkInFreeLists(FreeChunk* fc) const { |
ysr@3220 | 1382 | if (verify_chunk_is_linear_alloc_block(fc)) { |
ysr@3220 | 1383 | return true; |
ysr@3220 | 1384 | } else if (fc->size() < IndexSetSize) { |
ysr@3220 | 1385 | return verifyChunkInIndexedFreeLists(fc); |
ysr@3220 | 1386 | } else { |
duke@435 | 1387 | return dictionary()->verifyChunkInFreeLists(fc); |
duke@435 | 1388 | } |
duke@435 | 1389 | } |
duke@435 | 1390 | |
duke@435 | 1391 | #ifndef PRODUCT |
duke@435 | 1392 | void CompactibleFreeListSpace::assert_locked() const { |
duke@435 | 1393 | CMSLockVerifier::assert_locked(freelistLock(), parDictionaryAllocLock()); |
duke@435 | 1394 | } |
ysr@1580 | 1395 | |
ysr@1580 | 1396 | void CompactibleFreeListSpace::assert_locked(const Mutex* lock) const { |
ysr@1580 | 1397 | CMSLockVerifier::assert_locked(lock); |
ysr@1580 | 1398 | } |
duke@435 | 1399 | #endif |
duke@435 | 1400 | |
duke@435 | 1401 | FreeChunk* CompactibleFreeListSpace::allocateScratch(size_t size) { |
duke@435 | 1402 | // In the parallel case, the main thread holds the free list lock |
duke@435 | 1403 | // on behalf the parallel threads. |
duke@435 | 1404 | FreeChunk* fc; |
duke@435 | 1405 | { |
duke@435 | 1406 | // If GC is parallel, this might be called by several threads. |
duke@435 | 1407 | // This should be rare enough that the locking overhead won't affect |
duke@435 | 1408 | // the sequential code. |
duke@435 | 1409 | MutexLockerEx x(parDictionaryAllocLock(), |
duke@435 | 1410 | Mutex::_no_safepoint_check_flag); |
duke@435 | 1411 | fc = getChunkFromDictionary(size); |
duke@435 | 1412 | } |
duke@435 | 1413 | if (fc != NULL) { |
duke@435 | 1414 | fc->dontCoalesce(); |
duke@435 | 1415 | assert(fc->isFree(), "Should be free, but not coalescable"); |
duke@435 | 1416 | // Verify that the block offset table shows this to |
duke@435 | 1417 | // be a single block, but not one which is unallocated. |
duke@435 | 1418 | _bt.verify_single_block((HeapWord*)fc, fc->size()); |
duke@435 | 1419 | _bt.verify_not_unallocated((HeapWord*)fc, fc->size()); |
duke@435 | 1420 | } |
duke@435 | 1421 | return fc; |
duke@435 | 1422 | } |
duke@435 | 1423 | |
coleenp@548 | 1424 | oop CompactibleFreeListSpace::promote(oop obj, size_t obj_size) { |
duke@435 | 1425 | assert(obj_size == (size_t)obj->size(), "bad obj_size passed in"); |
duke@435 | 1426 | assert_locked(); |
duke@435 | 1427 | |
duke@435 | 1428 | // if we are tracking promotions, then first ensure space for |
duke@435 | 1429 | // promotion (including spooling space for saving header if necessary). |
duke@435 | 1430 | // then allocate and copy, then track promoted info if needed. |
duke@435 | 1431 | // When tracking (see PromotionInfo::track()), the mark word may |
duke@435 | 1432 | // be displaced and in this case restoration of the mark word |
duke@435 | 1433 | // occurs in the (oop_since_save_marks_)iterate phase. |
duke@435 | 1434 | if (_promoInfo.tracking() && !_promoInfo.ensure_spooling_space()) { |
duke@435 | 1435 | return NULL; |
duke@435 | 1436 | } |
duke@435 | 1437 | // Call the allocate(size_t, bool) form directly to avoid the |
duke@435 | 1438 | // additional call through the allocate(size_t) form. Having |
duke@435 | 1439 | // the compile inline the call is problematic because allocate(size_t) |
duke@435 | 1440 | // is a virtual method. |
duke@435 | 1441 | HeapWord* res = allocate(adjustObjectSize(obj_size)); |
duke@435 | 1442 | if (res != NULL) { |
duke@435 | 1443 | Copy::aligned_disjoint_words((HeapWord*)obj, res, obj_size); |
duke@435 | 1444 | // if we should be tracking promotions, do so. |
duke@435 | 1445 | if (_promoInfo.tracking()) { |
duke@435 | 1446 | _promoInfo.track((PromotedObject*)res); |
duke@435 | 1447 | } |
duke@435 | 1448 | } |
duke@435 | 1449 | return oop(res); |
duke@435 | 1450 | } |
duke@435 | 1451 | |
duke@435 | 1452 | HeapWord* |
duke@435 | 1453 | CompactibleFreeListSpace::getChunkFromSmallLinearAllocBlock(size_t size) { |
duke@435 | 1454 | assert_locked(); |
duke@435 | 1455 | assert(size >= MinChunkSize, "minimum chunk size"); |
duke@435 | 1456 | assert(size < _smallLinearAllocBlock._allocation_size_limit, |
duke@435 | 1457 | "maximum from smallLinearAllocBlock"); |
duke@435 | 1458 | return getChunkFromLinearAllocBlock(&_smallLinearAllocBlock, size); |
duke@435 | 1459 | } |
duke@435 | 1460 | |
duke@435 | 1461 | HeapWord* |
duke@435 | 1462 | CompactibleFreeListSpace::getChunkFromLinearAllocBlock(LinearAllocBlock *blk, |
duke@435 | 1463 | size_t size) { |
duke@435 | 1464 | assert_locked(); |
duke@435 | 1465 | assert(size >= MinChunkSize, "too small"); |
duke@435 | 1466 | HeapWord* res = NULL; |
duke@435 | 1467 | // Try to do linear allocation from blk, making sure that |
duke@435 | 1468 | if (blk->_word_size == 0) { |
duke@435 | 1469 | // We have probably been unable to fill this either in the prologue or |
duke@435 | 1470 | // when it was exhausted at the last linear allocation. Bail out until |
duke@435 | 1471 | // next time. |
duke@435 | 1472 | assert(blk->_ptr == NULL, "consistency check"); |
duke@435 | 1473 | return NULL; |
duke@435 | 1474 | } |
duke@435 | 1475 | assert(blk->_word_size != 0 && blk->_ptr != NULL, "consistency check"); |
duke@435 | 1476 | res = getChunkFromLinearAllocBlockRemainder(blk, size); |
duke@435 | 1477 | if (res != NULL) return res; |
duke@435 | 1478 | |
duke@435 | 1479 | // about to exhaust this linear allocation block |
duke@435 | 1480 | if (blk->_word_size == size) { // exactly satisfied |
duke@435 | 1481 | res = blk->_ptr; |
duke@435 | 1482 | _bt.allocated(res, blk->_word_size); |
duke@435 | 1483 | } else if (size + MinChunkSize <= blk->_refillSize) { |
ysr@1580 | 1484 | size_t sz = blk->_word_size; |
duke@435 | 1485 | // Update _unallocated_block if the size is such that chunk would be |
duke@435 | 1486 | // returned to the indexed free list. All other chunks in the indexed |
duke@435 | 1487 | // free lists are allocated from the dictionary so that _unallocated_block |
duke@435 | 1488 | // has already been adjusted for them. Do it here so that the cost |
duke@435 | 1489 | // for all chunks added back to the indexed free lists. |
ysr@1580 | 1490 | if (sz < SmallForDictionary) { |
ysr@1580 | 1491 | _bt.allocated(blk->_ptr, sz); |
duke@435 | 1492 | } |
duke@435 | 1493 | // Return the chunk that isn't big enough, and then refill below. |
ysr@1580 | 1494 | addChunkToFreeLists(blk->_ptr, sz); |
ysr@1580 | 1495 | splitBirth(sz); |
duke@435 | 1496 | // Don't keep statistics on adding back chunk from a LinAB. |
duke@435 | 1497 | } else { |
duke@435 | 1498 | // A refilled block would not satisfy the request. |
duke@435 | 1499 | return NULL; |
duke@435 | 1500 | } |
duke@435 | 1501 | |
duke@435 | 1502 | blk->_ptr = NULL; blk->_word_size = 0; |
duke@435 | 1503 | refillLinearAllocBlock(blk); |
duke@435 | 1504 | assert(blk->_ptr == NULL || blk->_word_size >= size + MinChunkSize, |
duke@435 | 1505 | "block was replenished"); |
duke@435 | 1506 | if (res != NULL) { |
duke@435 | 1507 | splitBirth(size); |
duke@435 | 1508 | repairLinearAllocBlock(blk); |
duke@435 | 1509 | } else if (blk->_ptr != NULL) { |
duke@435 | 1510 | res = blk->_ptr; |
duke@435 | 1511 | size_t blk_size = blk->_word_size; |
duke@435 | 1512 | blk->_word_size -= size; |
duke@435 | 1513 | blk->_ptr += size; |
duke@435 | 1514 | splitBirth(size); |
duke@435 | 1515 | repairLinearAllocBlock(blk); |
duke@435 | 1516 | // Update BOT last so that other (parallel) GC threads see a consistent |
duke@435 | 1517 | // view of the BOT and free blocks. |
duke@435 | 1518 | // Above must occur before BOT is updated below. |
ysr@2071 | 1519 | OrderAccess::storestore(); |
duke@435 | 1520 | _bt.split_block(res, blk_size, size); // adjust block offset table |
duke@435 | 1521 | } |
duke@435 | 1522 | return res; |
duke@435 | 1523 | } |
duke@435 | 1524 | |
duke@435 | 1525 | HeapWord* CompactibleFreeListSpace::getChunkFromLinearAllocBlockRemainder( |
duke@435 | 1526 | LinearAllocBlock* blk, |
duke@435 | 1527 | size_t size) { |
duke@435 | 1528 | assert_locked(); |
duke@435 | 1529 | assert(size >= MinChunkSize, "too small"); |
duke@435 | 1530 | |
duke@435 | 1531 | HeapWord* res = NULL; |
duke@435 | 1532 | // This is the common case. Keep it simple. |
duke@435 | 1533 | if (blk->_word_size >= size + MinChunkSize) { |
duke@435 | 1534 | assert(blk->_ptr != NULL, "consistency check"); |
duke@435 | 1535 | res = blk->_ptr; |
duke@435 | 1536 | // Note that the BOT is up-to-date for the linAB before allocation. It |
duke@435 | 1537 | // indicates the start of the linAB. The split_block() updates the |
duke@435 | 1538 | // BOT for the linAB after the allocation (indicates the start of the |
duke@435 | 1539 | // next chunk to be allocated). |
duke@435 | 1540 | size_t blk_size = blk->_word_size; |
duke@435 | 1541 | blk->_word_size -= size; |
duke@435 | 1542 | blk->_ptr += size; |
duke@435 | 1543 | splitBirth(size); |
duke@435 | 1544 | repairLinearAllocBlock(blk); |
duke@435 | 1545 | // Update BOT last so that other (parallel) GC threads see a consistent |
duke@435 | 1546 | // view of the BOT and free blocks. |
duke@435 | 1547 | // Above must occur before BOT is updated below. |
ysr@2071 | 1548 | OrderAccess::storestore(); |
duke@435 | 1549 | _bt.split_block(res, blk_size, size); // adjust block offset table |
duke@435 | 1550 | _bt.allocated(res, size); |
duke@435 | 1551 | } |
duke@435 | 1552 | return res; |
duke@435 | 1553 | } |
duke@435 | 1554 | |
duke@435 | 1555 | FreeChunk* |
duke@435 | 1556 | CompactibleFreeListSpace::getChunkFromIndexedFreeList(size_t size) { |
duke@435 | 1557 | assert_locked(); |
duke@435 | 1558 | assert(size < SmallForDictionary, "just checking"); |
duke@435 | 1559 | FreeChunk* res; |
duke@435 | 1560 | res = _indexedFreeList[size].getChunkAtHead(); |
duke@435 | 1561 | if (res == NULL) { |
duke@435 | 1562 | res = getChunkFromIndexedFreeListHelper(size); |
duke@435 | 1563 | } |
duke@435 | 1564 | _bt.verify_not_unallocated((HeapWord*) res, size); |
ysr@1580 | 1565 | assert(res == NULL || res->size() == size, "Incorrect block size"); |
duke@435 | 1566 | return res; |
duke@435 | 1567 | } |
duke@435 | 1568 | |
duke@435 | 1569 | FreeChunk* |
ysr@1580 | 1570 | CompactibleFreeListSpace::getChunkFromIndexedFreeListHelper(size_t size, |
ysr@1580 | 1571 | bool replenish) { |
duke@435 | 1572 | assert_locked(); |
duke@435 | 1573 | FreeChunk* fc = NULL; |
duke@435 | 1574 | if (size < SmallForDictionary) { |
duke@435 | 1575 | assert(_indexedFreeList[size].head() == NULL || |
duke@435 | 1576 | _indexedFreeList[size].surplus() <= 0, |
duke@435 | 1577 | "List for this size should be empty or under populated"); |
duke@435 | 1578 | // Try best fit in exact lists before replenishing the list |
duke@435 | 1579 | if (!bestFitFirst() || (fc = bestFitSmall(size)) == NULL) { |
duke@435 | 1580 | // Replenish list. |
duke@435 | 1581 | // |
duke@435 | 1582 | // Things tried that failed. |
duke@435 | 1583 | // Tried allocating out of the two LinAB's first before |
duke@435 | 1584 | // replenishing lists. |
duke@435 | 1585 | // Tried small linAB of size 256 (size in indexed list) |
duke@435 | 1586 | // and replenishing indexed lists from the small linAB. |
duke@435 | 1587 | // |
duke@435 | 1588 | FreeChunk* newFc = NULL; |
ysr@1580 | 1589 | const size_t replenish_size = CMSIndexedFreeListReplenish * size; |
duke@435 | 1590 | if (replenish_size < SmallForDictionary) { |
duke@435 | 1591 | // Do not replenish from an underpopulated size. |
duke@435 | 1592 | if (_indexedFreeList[replenish_size].surplus() > 0 && |
duke@435 | 1593 | _indexedFreeList[replenish_size].head() != NULL) { |
ysr@1580 | 1594 | newFc = _indexedFreeList[replenish_size].getChunkAtHead(); |
ysr@1580 | 1595 | } else if (bestFitFirst()) { |
duke@435 | 1596 | newFc = bestFitSmall(replenish_size); |
duke@435 | 1597 | } |
duke@435 | 1598 | } |
ysr@1580 | 1599 | if (newFc == NULL && replenish_size > size) { |
ysr@1580 | 1600 | assert(CMSIndexedFreeListReplenish > 1, "ctl pt invariant"); |
ysr@1580 | 1601 | newFc = getChunkFromIndexedFreeListHelper(replenish_size, false); |
ysr@1580 | 1602 | } |
ysr@1580 | 1603 | // Note: The stats update re split-death of block obtained above |
ysr@1580 | 1604 | // will be recorded below precisely when we know we are going to |
ysr@1580 | 1605 | // be actually splitting it into more than one pieces below. |
duke@435 | 1606 | if (newFc != NULL) { |
ysr@1580 | 1607 | if (replenish || CMSReplenishIntermediate) { |
ysr@1580 | 1608 | // Replenish this list and return one block to caller. |
ysr@1580 | 1609 | size_t i; |
ysr@1580 | 1610 | FreeChunk *curFc, *nextFc; |
ysr@1580 | 1611 | size_t num_blk = newFc->size() / size; |
ysr@1580 | 1612 | assert(num_blk >= 1, "Smaller than requested?"); |
ysr@1580 | 1613 | assert(newFc->size() % size == 0, "Should be integral multiple of request"); |
ysr@1580 | 1614 | if (num_blk > 1) { |
ysr@1580 | 1615 | // we are sure we will be splitting the block just obtained |
ysr@1580 | 1616 | // into multiple pieces; record the split-death of the original |
ysr@1580 | 1617 | splitDeath(replenish_size); |
ysr@1580 | 1618 | } |
ysr@1580 | 1619 | // carve up and link blocks 0, ..., num_blk - 2 |
ysr@1580 | 1620 | // The last chunk is not added to the lists but is returned as the |
ysr@1580 | 1621 | // free chunk. |
ysr@1580 | 1622 | for (curFc = newFc, nextFc = (FreeChunk*)((HeapWord*)curFc + size), |
ysr@1580 | 1623 | i = 0; |
ysr@1580 | 1624 | i < (num_blk - 1); |
ysr@1580 | 1625 | curFc = nextFc, nextFc = (FreeChunk*)((HeapWord*)nextFc + size), |
ysr@1580 | 1626 | i++) { |
ysr@1580 | 1627 | curFc->setSize(size); |
ysr@1580 | 1628 | // Don't record this as a return in order to try and |
ysr@1580 | 1629 | // determine the "returns" from a GC. |
ysr@1580 | 1630 | _bt.verify_not_unallocated((HeapWord*) fc, size); |
ysr@1580 | 1631 | _indexedFreeList[size].returnChunkAtTail(curFc, false); |
ysr@1580 | 1632 | _bt.mark_block((HeapWord*)curFc, size); |
ysr@1580 | 1633 | splitBirth(size); |
ysr@1580 | 1634 | // Don't record the initial population of the indexed list |
ysr@1580 | 1635 | // as a split birth. |
ysr@1580 | 1636 | } |
ysr@1580 | 1637 | |
ysr@1580 | 1638 | // check that the arithmetic was OK above |
ysr@1580 | 1639 | assert((HeapWord*)nextFc == (HeapWord*)newFc + num_blk*size, |
ysr@1580 | 1640 | "inconsistency in carving newFc"); |
duke@435 | 1641 | curFc->setSize(size); |
duke@435 | 1642 | _bt.mark_block((HeapWord*)curFc, size); |
duke@435 | 1643 | splitBirth(size); |
ysr@1580 | 1644 | fc = curFc; |
ysr@1580 | 1645 | } else { |
ysr@1580 | 1646 | // Return entire block to caller |
ysr@1580 | 1647 | fc = newFc; |
duke@435 | 1648 | } |
duke@435 | 1649 | } |
duke@435 | 1650 | } |
duke@435 | 1651 | } else { |
duke@435 | 1652 | // Get a free chunk from the free chunk dictionary to be returned to |
duke@435 | 1653 | // replenish the indexed free list. |
duke@435 | 1654 | fc = getChunkFromDictionaryExact(size); |
duke@435 | 1655 | } |
ysr@1580 | 1656 | // assert(fc == NULL || fc->isFree(), "Should be returning a free chunk"); |
duke@435 | 1657 | return fc; |
duke@435 | 1658 | } |
duke@435 | 1659 | |
duke@435 | 1660 | FreeChunk* |
duke@435 | 1661 | CompactibleFreeListSpace::getChunkFromDictionary(size_t size) { |
duke@435 | 1662 | assert_locked(); |
duke@435 | 1663 | FreeChunk* fc = _dictionary->getChunk(size); |
duke@435 | 1664 | if (fc == NULL) { |
duke@435 | 1665 | return NULL; |
duke@435 | 1666 | } |
duke@435 | 1667 | _bt.allocated((HeapWord*)fc, fc->size()); |
duke@435 | 1668 | if (fc->size() >= size + MinChunkSize) { |
duke@435 | 1669 | fc = splitChunkAndReturnRemainder(fc, size); |
duke@435 | 1670 | } |
duke@435 | 1671 | assert(fc->size() >= size, "chunk too small"); |
duke@435 | 1672 | assert(fc->size() < size + MinChunkSize, "chunk too big"); |
duke@435 | 1673 | _bt.verify_single_block((HeapWord*)fc, fc->size()); |
duke@435 | 1674 | return fc; |
duke@435 | 1675 | } |
duke@435 | 1676 | |
duke@435 | 1677 | FreeChunk* |
duke@435 | 1678 | CompactibleFreeListSpace::getChunkFromDictionaryExact(size_t size) { |
duke@435 | 1679 | assert_locked(); |
duke@435 | 1680 | FreeChunk* fc = _dictionary->getChunk(size); |
duke@435 | 1681 | if (fc == NULL) { |
duke@435 | 1682 | return fc; |
duke@435 | 1683 | } |
duke@435 | 1684 | _bt.allocated((HeapWord*)fc, fc->size()); |
duke@435 | 1685 | if (fc->size() == size) { |
duke@435 | 1686 | _bt.verify_single_block((HeapWord*)fc, size); |
duke@435 | 1687 | return fc; |
duke@435 | 1688 | } |
duke@435 | 1689 | assert(fc->size() > size, "getChunk() guarantee"); |
duke@435 | 1690 | if (fc->size() < size + MinChunkSize) { |
duke@435 | 1691 | // Return the chunk to the dictionary and go get a bigger one. |
duke@435 | 1692 | returnChunkToDictionary(fc); |
duke@435 | 1693 | fc = _dictionary->getChunk(size + MinChunkSize); |
duke@435 | 1694 | if (fc == NULL) { |
duke@435 | 1695 | return NULL; |
duke@435 | 1696 | } |
duke@435 | 1697 | _bt.allocated((HeapWord*)fc, fc->size()); |
duke@435 | 1698 | } |
duke@435 | 1699 | assert(fc->size() >= size + MinChunkSize, "tautology"); |
duke@435 | 1700 | fc = splitChunkAndReturnRemainder(fc, size); |
duke@435 | 1701 | assert(fc->size() == size, "chunk is wrong size"); |
duke@435 | 1702 | _bt.verify_single_block((HeapWord*)fc, size); |
duke@435 | 1703 | return fc; |
duke@435 | 1704 | } |
duke@435 | 1705 | |
duke@435 | 1706 | void |
duke@435 | 1707 | CompactibleFreeListSpace::returnChunkToDictionary(FreeChunk* chunk) { |
duke@435 | 1708 | assert_locked(); |
duke@435 | 1709 | |
duke@435 | 1710 | size_t size = chunk->size(); |
duke@435 | 1711 | _bt.verify_single_block((HeapWord*)chunk, size); |
duke@435 | 1712 | // adjust _unallocated_block downward, as necessary |
duke@435 | 1713 | _bt.freed((HeapWord*)chunk, size); |
duke@435 | 1714 | _dictionary->returnChunk(chunk); |
ysr@1580 | 1715 | #ifndef PRODUCT |
ysr@1580 | 1716 | if (CMSCollector::abstract_state() != CMSCollector::Sweeping) { |
ysr@1580 | 1717 | TreeChunk::as_TreeChunk(chunk)->list()->verify_stats(); |
ysr@1580 | 1718 | } |
ysr@1580 | 1719 | #endif // PRODUCT |
duke@435 | 1720 | } |
duke@435 | 1721 | |
duke@435 | 1722 | void |
duke@435 | 1723 | CompactibleFreeListSpace::returnChunkToFreeList(FreeChunk* fc) { |
duke@435 | 1724 | assert_locked(); |
duke@435 | 1725 | size_t size = fc->size(); |
duke@435 | 1726 | _bt.verify_single_block((HeapWord*) fc, size); |
duke@435 | 1727 | _bt.verify_not_unallocated((HeapWord*) fc, size); |
duke@435 | 1728 | if (_adaptive_freelists) { |
duke@435 | 1729 | _indexedFreeList[size].returnChunkAtTail(fc); |
duke@435 | 1730 | } else { |
duke@435 | 1731 | _indexedFreeList[size].returnChunkAtHead(fc); |
duke@435 | 1732 | } |
ysr@1580 | 1733 | #ifndef PRODUCT |
ysr@1580 | 1734 | if (CMSCollector::abstract_state() != CMSCollector::Sweeping) { |
ysr@1580 | 1735 | _indexedFreeList[size].verify_stats(); |
ysr@1580 | 1736 | } |
ysr@1580 | 1737 | #endif // PRODUCT |
duke@435 | 1738 | } |
duke@435 | 1739 | |
duke@435 | 1740 | // Add chunk to end of last block -- if it's the largest |
duke@435 | 1741 | // block -- and update BOT and census data. We would |
duke@435 | 1742 | // of course have preferred to coalesce it with the |
duke@435 | 1743 | // last block, but it's currently less expensive to find the |
duke@435 | 1744 | // largest block than it is to find the last. |
duke@435 | 1745 | void |
duke@435 | 1746 | CompactibleFreeListSpace::addChunkToFreeListsAtEndRecordingStats( |
duke@435 | 1747 | HeapWord* chunk, size_t size) { |
duke@435 | 1748 | // check that the chunk does lie in this space! |
duke@435 | 1749 | assert(chunk != NULL && is_in_reserved(chunk), "Not in this space!"); |
duke@435 | 1750 | // One of the parallel gc task threads may be here |
duke@435 | 1751 | // whilst others are allocating. |
duke@435 | 1752 | Mutex* lock = NULL; |
duke@435 | 1753 | if (ParallelGCThreads != 0) { |
duke@435 | 1754 | lock = &_parDictionaryAllocLock; |
duke@435 | 1755 | } |
duke@435 | 1756 | FreeChunk* ec; |
duke@435 | 1757 | { |
duke@435 | 1758 | MutexLockerEx x(lock, Mutex::_no_safepoint_check_flag); |
duke@435 | 1759 | ec = dictionary()->findLargestDict(); // get largest block |
duke@435 | 1760 | if (ec != NULL && ec->end() == chunk) { |
duke@435 | 1761 | // It's a coterminal block - we can coalesce. |
duke@435 | 1762 | size_t old_size = ec->size(); |
duke@435 | 1763 | coalDeath(old_size); |
duke@435 | 1764 | removeChunkFromDictionary(ec); |
duke@435 | 1765 | size += old_size; |
duke@435 | 1766 | } else { |
duke@435 | 1767 | ec = (FreeChunk*)chunk; |
duke@435 | 1768 | } |
duke@435 | 1769 | } |
duke@435 | 1770 | ec->setSize(size); |
duke@435 | 1771 | debug_only(ec->mangleFreed(size)); |
duke@435 | 1772 | if (size < SmallForDictionary) { |
duke@435 | 1773 | lock = _indexedFreeListParLocks[size]; |
duke@435 | 1774 | } |
duke@435 | 1775 | MutexLockerEx x(lock, Mutex::_no_safepoint_check_flag); |
duke@435 | 1776 | addChunkAndRepairOffsetTable((HeapWord*)ec, size, true); |
duke@435 | 1777 | // record the birth under the lock since the recording involves |
duke@435 | 1778 | // manipulation of the list on which the chunk lives and |
duke@435 | 1779 | // if the chunk is allocated and is the last on the list, |
duke@435 | 1780 | // the list can go away. |
duke@435 | 1781 | coalBirth(size); |
duke@435 | 1782 | } |
duke@435 | 1783 | |
duke@435 | 1784 | void |
duke@435 | 1785 | CompactibleFreeListSpace::addChunkToFreeLists(HeapWord* chunk, |
duke@435 | 1786 | size_t size) { |
duke@435 | 1787 | // check that the chunk does lie in this space! |
duke@435 | 1788 | assert(chunk != NULL && is_in_reserved(chunk), "Not in this space!"); |
duke@435 | 1789 | assert_locked(); |
duke@435 | 1790 | _bt.verify_single_block(chunk, size); |
duke@435 | 1791 | |
duke@435 | 1792 | FreeChunk* fc = (FreeChunk*) chunk; |
duke@435 | 1793 | fc->setSize(size); |
duke@435 | 1794 | debug_only(fc->mangleFreed(size)); |
duke@435 | 1795 | if (size < SmallForDictionary) { |
duke@435 | 1796 | returnChunkToFreeList(fc); |
duke@435 | 1797 | } else { |
duke@435 | 1798 | returnChunkToDictionary(fc); |
duke@435 | 1799 | } |
duke@435 | 1800 | } |
duke@435 | 1801 | |
duke@435 | 1802 | void |
duke@435 | 1803 | CompactibleFreeListSpace::addChunkAndRepairOffsetTable(HeapWord* chunk, |
duke@435 | 1804 | size_t size, bool coalesced) { |
duke@435 | 1805 | assert_locked(); |
duke@435 | 1806 | assert(chunk != NULL, "null chunk"); |
duke@435 | 1807 | if (coalesced) { |
duke@435 | 1808 | // repair BOT |
duke@435 | 1809 | _bt.single_block(chunk, size); |
duke@435 | 1810 | } |
duke@435 | 1811 | addChunkToFreeLists(chunk, size); |
duke@435 | 1812 | } |
duke@435 | 1813 | |
duke@435 | 1814 | // We _must_ find the purported chunk on our free lists; |
duke@435 | 1815 | // we assert if we don't. |
duke@435 | 1816 | void |
duke@435 | 1817 | CompactibleFreeListSpace::removeFreeChunkFromFreeLists(FreeChunk* fc) { |
duke@435 | 1818 | size_t size = fc->size(); |
duke@435 | 1819 | assert_locked(); |
duke@435 | 1820 | debug_only(verifyFreeLists()); |
duke@435 | 1821 | if (size < SmallForDictionary) { |
duke@435 | 1822 | removeChunkFromIndexedFreeList(fc); |
duke@435 | 1823 | } else { |
duke@435 | 1824 | removeChunkFromDictionary(fc); |
duke@435 | 1825 | } |
duke@435 | 1826 | _bt.verify_single_block((HeapWord*)fc, size); |
duke@435 | 1827 | debug_only(verifyFreeLists()); |
duke@435 | 1828 | } |
duke@435 | 1829 | |
duke@435 | 1830 | void |
duke@435 | 1831 | CompactibleFreeListSpace::removeChunkFromDictionary(FreeChunk* fc) { |
duke@435 | 1832 | size_t size = fc->size(); |
duke@435 | 1833 | assert_locked(); |
duke@435 | 1834 | assert(fc != NULL, "null chunk"); |
duke@435 | 1835 | _bt.verify_single_block((HeapWord*)fc, size); |
duke@435 | 1836 | _dictionary->removeChunk(fc); |
duke@435 | 1837 | // adjust _unallocated_block upward, as necessary |
duke@435 | 1838 | _bt.allocated((HeapWord*)fc, size); |
duke@435 | 1839 | } |
duke@435 | 1840 | |
duke@435 | 1841 | void |
duke@435 | 1842 | CompactibleFreeListSpace::removeChunkFromIndexedFreeList(FreeChunk* fc) { |
duke@435 | 1843 | assert_locked(); |
duke@435 | 1844 | size_t size = fc->size(); |
duke@435 | 1845 | _bt.verify_single_block((HeapWord*)fc, size); |
duke@435 | 1846 | NOT_PRODUCT( |
duke@435 | 1847 | if (FLSVerifyIndexTable) { |
duke@435 | 1848 | verifyIndexedFreeList(size); |
duke@435 | 1849 | } |
duke@435 | 1850 | ) |
duke@435 | 1851 | _indexedFreeList[size].removeChunk(fc); |
duke@435 | 1852 | NOT_PRODUCT( |
duke@435 | 1853 | if (FLSVerifyIndexTable) { |
duke@435 | 1854 | verifyIndexedFreeList(size); |
duke@435 | 1855 | } |
duke@435 | 1856 | ) |
duke@435 | 1857 | } |
duke@435 | 1858 | |
duke@435 | 1859 | FreeChunk* CompactibleFreeListSpace::bestFitSmall(size_t numWords) { |
duke@435 | 1860 | /* A hint is the next larger size that has a surplus. |
duke@435 | 1861 | Start search at a size large enough to guarantee that |
duke@435 | 1862 | the excess is >= MIN_CHUNK. */ |
duke@435 | 1863 | size_t start = align_object_size(numWords + MinChunkSize); |
duke@435 | 1864 | if (start < IndexSetSize) { |
duke@435 | 1865 | FreeList* it = _indexedFreeList; |
duke@435 | 1866 | size_t hint = _indexedFreeList[start].hint(); |
duke@435 | 1867 | while (hint < IndexSetSize) { |
duke@435 | 1868 | assert(hint % MinObjAlignment == 0, "hint should be aligned"); |
duke@435 | 1869 | FreeList *fl = &_indexedFreeList[hint]; |
duke@435 | 1870 | if (fl->surplus() > 0 && fl->head() != NULL) { |
duke@435 | 1871 | // Found a list with surplus, reset original hint |
duke@435 | 1872 | // and split out a free chunk which is returned. |
duke@435 | 1873 | _indexedFreeList[start].set_hint(hint); |
duke@435 | 1874 | FreeChunk* res = getFromListGreater(fl, numWords); |
duke@435 | 1875 | assert(res == NULL || res->isFree(), |
duke@435 | 1876 | "Should be returning a free chunk"); |
duke@435 | 1877 | return res; |
duke@435 | 1878 | } |
duke@435 | 1879 | hint = fl->hint(); /* keep looking */ |
duke@435 | 1880 | } |
duke@435 | 1881 | /* None found. */ |
duke@435 | 1882 | it[start].set_hint(IndexSetSize); |
duke@435 | 1883 | } |
duke@435 | 1884 | return NULL; |
duke@435 | 1885 | } |
duke@435 | 1886 | |
duke@435 | 1887 | /* Requires fl->size >= numWords + MinChunkSize */ |
duke@435 | 1888 | FreeChunk* CompactibleFreeListSpace::getFromListGreater(FreeList* fl, |
duke@435 | 1889 | size_t numWords) { |
duke@435 | 1890 | FreeChunk *curr = fl->head(); |
duke@435 | 1891 | size_t oldNumWords = curr->size(); |
duke@435 | 1892 | assert(numWords >= MinChunkSize, "Word size is too small"); |
duke@435 | 1893 | assert(curr != NULL, "List is empty"); |
duke@435 | 1894 | assert(oldNumWords >= numWords + MinChunkSize, |
duke@435 | 1895 | "Size of chunks in the list is too small"); |
duke@435 | 1896 | |
duke@435 | 1897 | fl->removeChunk(curr); |
duke@435 | 1898 | // recorded indirectly by splitChunkAndReturnRemainder - |
duke@435 | 1899 | // smallSplit(oldNumWords, numWords); |
duke@435 | 1900 | FreeChunk* new_chunk = splitChunkAndReturnRemainder(curr, numWords); |
duke@435 | 1901 | // Does anything have to be done for the remainder in terms of |
duke@435 | 1902 | // fixing the card table? |
duke@435 | 1903 | assert(new_chunk == NULL || new_chunk->isFree(), |
duke@435 | 1904 | "Should be returning a free chunk"); |
duke@435 | 1905 | return new_chunk; |
duke@435 | 1906 | } |
duke@435 | 1907 | |
duke@435 | 1908 | FreeChunk* |
duke@435 | 1909 | CompactibleFreeListSpace::splitChunkAndReturnRemainder(FreeChunk* chunk, |
duke@435 | 1910 | size_t new_size) { |
duke@435 | 1911 | assert_locked(); |
duke@435 | 1912 | size_t size = chunk->size(); |
duke@435 | 1913 | assert(size > new_size, "Split from a smaller block?"); |
duke@435 | 1914 | assert(is_aligned(chunk), "alignment problem"); |
duke@435 | 1915 | assert(size == adjustObjectSize(size), "alignment problem"); |
duke@435 | 1916 | size_t rem_size = size - new_size; |
duke@435 | 1917 | assert(rem_size == adjustObjectSize(rem_size), "alignment problem"); |
duke@435 | 1918 | assert(rem_size >= MinChunkSize, "Free chunk smaller than minimum"); |
duke@435 | 1919 | FreeChunk* ffc = (FreeChunk*)((HeapWord*)chunk + new_size); |
duke@435 | 1920 | assert(is_aligned(ffc), "alignment problem"); |
duke@435 | 1921 | ffc->setSize(rem_size); |
duke@435 | 1922 | ffc->linkNext(NULL); |
duke@435 | 1923 | ffc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. |
duke@435 | 1924 | // Above must occur before BOT is updated below. |
duke@435 | 1925 | // adjust block offset table |
ysr@2071 | 1926 | OrderAccess::storestore(); |
ysr@2071 | 1927 | assert(chunk->isFree() && ffc->isFree(), "Error"); |
duke@435 | 1928 | _bt.split_block((HeapWord*)chunk, chunk->size(), new_size); |
duke@435 | 1929 | if (rem_size < SmallForDictionary) { |
duke@435 | 1930 | bool is_par = (SharedHeap::heap()->n_par_threads() > 0); |
duke@435 | 1931 | if (is_par) _indexedFreeListParLocks[rem_size]->lock(); |
jmasa@3294 | 1932 | assert(!is_par || |
jmasa@3294 | 1933 | (SharedHeap::heap()->n_par_threads() == |
jmasa@3294 | 1934 | SharedHeap::heap()->workers()->active_workers()), "Mismatch"); |
duke@435 | 1935 | returnChunkToFreeList(ffc); |
duke@435 | 1936 | split(size, rem_size); |
duke@435 | 1937 | if (is_par) _indexedFreeListParLocks[rem_size]->unlock(); |
duke@435 | 1938 | } else { |
duke@435 | 1939 | returnChunkToDictionary(ffc); |
duke@435 | 1940 | split(size ,rem_size); |
duke@435 | 1941 | } |
duke@435 | 1942 | chunk->setSize(new_size); |
duke@435 | 1943 | return chunk; |
duke@435 | 1944 | } |
duke@435 | 1945 | |
duke@435 | 1946 | void |
duke@435 | 1947 | CompactibleFreeListSpace::sweep_completed() { |
duke@435 | 1948 | // Now that space is probably plentiful, refill linear |
duke@435 | 1949 | // allocation blocks as needed. |
duke@435 | 1950 | refillLinearAllocBlocksIfNeeded(); |
duke@435 | 1951 | } |
duke@435 | 1952 | |
duke@435 | 1953 | void |
duke@435 | 1954 | CompactibleFreeListSpace::gc_prologue() { |
duke@435 | 1955 | assert_locked(); |
duke@435 | 1956 | if (PrintFLSStatistics != 0) { |
duke@435 | 1957 | gclog_or_tty->print("Before GC:\n"); |
duke@435 | 1958 | reportFreeListStatistics(); |
duke@435 | 1959 | } |
duke@435 | 1960 | refillLinearAllocBlocksIfNeeded(); |
duke@435 | 1961 | } |
duke@435 | 1962 | |
duke@435 | 1963 | void |
duke@435 | 1964 | CompactibleFreeListSpace::gc_epilogue() { |
duke@435 | 1965 | assert_locked(); |
duke@435 | 1966 | if (PrintGCDetails && Verbose && !_adaptive_freelists) { |
duke@435 | 1967 | if (_smallLinearAllocBlock._word_size == 0) |
duke@435 | 1968 | warning("CompactibleFreeListSpace(epilogue):: Linear allocation failure"); |
duke@435 | 1969 | } |
duke@435 | 1970 | assert(_promoInfo.noPromotions(), "_promoInfo inconsistency"); |
duke@435 | 1971 | _promoInfo.stopTrackingPromotions(); |
duke@435 | 1972 | repairLinearAllocationBlocks(); |
duke@435 | 1973 | // Print Space's stats |
duke@435 | 1974 | if (PrintFLSStatistics != 0) { |
duke@435 | 1975 | gclog_or_tty->print("After GC:\n"); |
duke@435 | 1976 | reportFreeListStatistics(); |
duke@435 | 1977 | } |
duke@435 | 1978 | } |
duke@435 | 1979 | |
duke@435 | 1980 | // Iteration support, mostly delegated from a CMS generation |
duke@435 | 1981 | |
duke@435 | 1982 | void CompactibleFreeListSpace::save_marks() { |
ysr@2825 | 1983 | assert(Thread::current()->is_VM_thread(), |
ysr@2825 | 1984 | "Global variable should only be set when single-threaded"); |
ysr@2825 | 1985 | // Mark the "end" of the used space at the time of this call; |
duke@435 | 1986 | // note, however, that promoted objects from this point |
duke@435 | 1987 | // on are tracked in the _promoInfo below. |
ysr@2071 | 1988 | set_saved_mark_word(unallocated_block()); |
ysr@2825 | 1989 | #ifdef ASSERT |
ysr@2825 | 1990 | // Check the sanity of save_marks() etc. |
ysr@2825 | 1991 | MemRegion ur = used_region(); |
ysr@2825 | 1992 | MemRegion urasm = used_region_at_save_marks(); |
ysr@2825 | 1993 | assert(ur.contains(urasm), |
ysr@2825 | 1994 | err_msg(" Error at save_marks(): [" PTR_FORMAT "," PTR_FORMAT ")" |
ysr@2825 | 1995 | " should contain [" PTR_FORMAT "," PTR_FORMAT ")", |
ysr@2825 | 1996 | ur.start(), ur.end(), urasm.start(), urasm.end())); |
ysr@2825 | 1997 | #endif |
duke@435 | 1998 | // inform allocator that promotions should be tracked. |
duke@435 | 1999 | assert(_promoInfo.noPromotions(), "_promoInfo inconsistency"); |
duke@435 | 2000 | _promoInfo.startTrackingPromotions(); |
duke@435 | 2001 | } |
duke@435 | 2002 | |
duke@435 | 2003 | bool CompactibleFreeListSpace::no_allocs_since_save_marks() { |
duke@435 | 2004 | assert(_promoInfo.tracking(), "No preceding save_marks?"); |
ysr@2132 | 2005 | assert(SharedHeap::heap()->n_par_threads() == 0, |
ysr@2132 | 2006 | "Shouldn't be called if using parallel gc."); |
duke@435 | 2007 | return _promoInfo.noPromotions(); |
duke@435 | 2008 | } |
duke@435 | 2009 | |
duke@435 | 2010 | #define CFLS_OOP_SINCE_SAVE_MARKS_DEFN(OopClosureType, nv_suffix) \ |
duke@435 | 2011 | \ |
duke@435 | 2012 | void CompactibleFreeListSpace:: \ |
duke@435 | 2013 | oop_since_save_marks_iterate##nv_suffix(OopClosureType* blk) { \ |
duke@435 | 2014 | assert(SharedHeap::heap()->n_par_threads() == 0, \ |
duke@435 | 2015 | "Shouldn't be called (yet) during parallel part of gc."); \ |
duke@435 | 2016 | _promoInfo.promoted_oops_iterate##nv_suffix(blk); \ |
duke@435 | 2017 | /* \ |
duke@435 | 2018 | * This also restores any displaced headers and removes the elements from \ |
duke@435 | 2019 | * the iteration set as they are processed, so that we have a clean slate \ |
duke@435 | 2020 | * at the end of the iteration. Note, thus, that if new objects are \ |
duke@435 | 2021 | * promoted as a result of the iteration they are iterated over as well. \ |
duke@435 | 2022 | */ \ |
duke@435 | 2023 | assert(_promoInfo.noPromotions(), "_promoInfo inconsistency"); \ |
duke@435 | 2024 | } |
duke@435 | 2025 | |
duke@435 | 2026 | ALL_SINCE_SAVE_MARKS_CLOSURES(CFLS_OOP_SINCE_SAVE_MARKS_DEFN) |
duke@435 | 2027 | |
duke@435 | 2028 | |
duke@435 | 2029 | void CompactibleFreeListSpace::object_iterate_since_last_GC(ObjectClosure* cl) { |
duke@435 | 2030 | // ugghh... how would one do this efficiently for a non-contiguous space? |
duke@435 | 2031 | guarantee(false, "NYI"); |
duke@435 | 2032 | } |
duke@435 | 2033 | |
ysr@447 | 2034 | bool CompactibleFreeListSpace::linearAllocationWouldFail() const { |
duke@435 | 2035 | return _smallLinearAllocBlock._word_size == 0; |
duke@435 | 2036 | } |
duke@435 | 2037 | |
duke@435 | 2038 | void CompactibleFreeListSpace::repairLinearAllocationBlocks() { |
duke@435 | 2039 | // Fix up linear allocation blocks to look like free blocks |
duke@435 | 2040 | repairLinearAllocBlock(&_smallLinearAllocBlock); |
duke@435 | 2041 | } |
duke@435 | 2042 | |
duke@435 | 2043 | void CompactibleFreeListSpace::repairLinearAllocBlock(LinearAllocBlock* blk) { |
duke@435 | 2044 | assert_locked(); |
duke@435 | 2045 | if (blk->_ptr != NULL) { |
duke@435 | 2046 | assert(blk->_word_size != 0 && blk->_word_size >= MinChunkSize, |
duke@435 | 2047 | "Minimum block size requirement"); |
duke@435 | 2048 | FreeChunk* fc = (FreeChunk*)(blk->_ptr); |
duke@435 | 2049 | fc->setSize(blk->_word_size); |
duke@435 | 2050 | fc->linkPrev(NULL); // mark as free |
duke@435 | 2051 | fc->dontCoalesce(); |
duke@435 | 2052 | assert(fc->isFree(), "just marked it free"); |
duke@435 | 2053 | assert(fc->cantCoalesce(), "just marked it uncoalescable"); |
duke@435 | 2054 | } |
duke@435 | 2055 | } |
duke@435 | 2056 | |
duke@435 | 2057 | void CompactibleFreeListSpace::refillLinearAllocBlocksIfNeeded() { |
duke@435 | 2058 | assert_locked(); |
duke@435 | 2059 | if (_smallLinearAllocBlock._ptr == NULL) { |
duke@435 | 2060 | assert(_smallLinearAllocBlock._word_size == 0, |
duke@435 | 2061 | "Size of linAB should be zero if the ptr is NULL"); |
duke@435 | 2062 | // Reset the linAB refill and allocation size limit. |
duke@435 | 2063 | _smallLinearAllocBlock.set(0, 0, 1024*SmallForLinearAlloc, SmallForLinearAlloc); |
duke@435 | 2064 | } |
duke@435 | 2065 | refillLinearAllocBlockIfNeeded(&_smallLinearAllocBlock); |
duke@435 | 2066 | } |
duke@435 | 2067 | |
duke@435 | 2068 | void |
duke@435 | 2069 | CompactibleFreeListSpace::refillLinearAllocBlockIfNeeded(LinearAllocBlock* blk) { |
duke@435 | 2070 | assert_locked(); |
duke@435 | 2071 | assert((blk->_ptr == NULL && blk->_word_size == 0) || |
duke@435 | 2072 | (blk->_ptr != NULL && blk->_word_size >= MinChunkSize), |
duke@435 | 2073 | "blk invariant"); |
duke@435 | 2074 | if (blk->_ptr == NULL) { |
duke@435 | 2075 | refillLinearAllocBlock(blk); |
duke@435 | 2076 | } |
duke@435 | 2077 | if (PrintMiscellaneous && Verbose) { |
duke@435 | 2078 | if (blk->_word_size == 0) { |
duke@435 | 2079 | warning("CompactibleFreeListSpace(prologue):: Linear allocation failure"); |
duke@435 | 2080 | } |
duke@435 | 2081 | } |
duke@435 | 2082 | } |
duke@435 | 2083 | |
duke@435 | 2084 | void |
duke@435 | 2085 | CompactibleFreeListSpace::refillLinearAllocBlock(LinearAllocBlock* blk) { |
duke@435 | 2086 | assert_locked(); |
duke@435 | 2087 | assert(blk->_word_size == 0 && blk->_ptr == NULL, |
duke@435 | 2088 | "linear allocation block should be empty"); |
duke@435 | 2089 | FreeChunk* fc; |
duke@435 | 2090 | if (blk->_refillSize < SmallForDictionary && |
duke@435 | 2091 | (fc = getChunkFromIndexedFreeList(blk->_refillSize)) != NULL) { |
duke@435 | 2092 | // A linAB's strategy might be to use small sizes to reduce |
duke@435 | 2093 | // fragmentation but still get the benefits of allocation from a |
duke@435 | 2094 | // linAB. |
duke@435 | 2095 | } else { |
duke@435 | 2096 | fc = getChunkFromDictionary(blk->_refillSize); |
duke@435 | 2097 | } |
duke@435 | 2098 | if (fc != NULL) { |
duke@435 | 2099 | blk->_ptr = (HeapWord*)fc; |
duke@435 | 2100 | blk->_word_size = fc->size(); |
duke@435 | 2101 | fc->dontCoalesce(); // to prevent sweeper from sweeping us up |
duke@435 | 2102 | } |
duke@435 | 2103 | } |
duke@435 | 2104 | |
ysr@447 | 2105 | // Support for concurrent collection policy decisions. |
ysr@447 | 2106 | bool CompactibleFreeListSpace::should_concurrent_collect() const { |
ysr@447 | 2107 | // In the future we might want to add in frgamentation stats -- |
ysr@447 | 2108 | // including erosion of the "mountain" into this decision as well. |
ysr@447 | 2109 | return !adaptive_freelists() && linearAllocationWouldFail(); |
ysr@447 | 2110 | } |
ysr@447 | 2111 | |
duke@435 | 2112 | // Support for compaction |
duke@435 | 2113 | |
duke@435 | 2114 | void CompactibleFreeListSpace::prepare_for_compaction(CompactPoint* cp) { |
duke@435 | 2115 | SCAN_AND_FORWARD(cp,end,block_is_obj,block_size); |
duke@435 | 2116 | // prepare_for_compaction() uses the space between live objects |
duke@435 | 2117 | // so that later phase can skip dead space quickly. So verification |
duke@435 | 2118 | // of the free lists doesn't work after. |
duke@435 | 2119 | } |
duke@435 | 2120 | |
duke@435 | 2121 | #define obj_size(q) adjustObjectSize(oop(q)->size()) |
duke@435 | 2122 | #define adjust_obj_size(s) adjustObjectSize(s) |
duke@435 | 2123 | |
duke@435 | 2124 | void CompactibleFreeListSpace::adjust_pointers() { |
duke@435 | 2125 | // In other versions of adjust_pointers(), a bail out |
duke@435 | 2126 | // based on the amount of live data in the generation |
duke@435 | 2127 | // (i.e., if 0, bail out) may be used. |
duke@435 | 2128 | // Cannot test used() == 0 here because the free lists have already |
duke@435 | 2129 | // been mangled by the compaction. |
duke@435 | 2130 | |
duke@435 | 2131 | SCAN_AND_ADJUST_POINTERS(adjust_obj_size); |
duke@435 | 2132 | // See note about verification in prepare_for_compaction(). |
duke@435 | 2133 | } |
duke@435 | 2134 | |
duke@435 | 2135 | void CompactibleFreeListSpace::compact() { |
duke@435 | 2136 | SCAN_AND_COMPACT(obj_size); |
duke@435 | 2137 | } |
duke@435 | 2138 | |
duke@435 | 2139 | // fragmentation_metric = 1 - [sum of (fbs**2) / (sum of fbs)**2] |
duke@435 | 2140 | // where fbs is free block sizes |
duke@435 | 2141 | double CompactibleFreeListSpace::flsFrag() const { |
duke@435 | 2142 | size_t itabFree = totalSizeInIndexedFreeLists(); |
duke@435 | 2143 | double frag = 0.0; |
duke@435 | 2144 | size_t i; |
duke@435 | 2145 | |
duke@435 | 2146 | for (i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 2147 | double sz = i; |
duke@435 | 2148 | frag += _indexedFreeList[i].count() * (sz * sz); |
duke@435 | 2149 | } |
duke@435 | 2150 | |
duke@435 | 2151 | double totFree = itabFree + |
duke@435 | 2152 | _dictionary->totalChunkSize(DEBUG_ONLY(freelistLock())); |
duke@435 | 2153 | if (totFree > 0) { |
duke@435 | 2154 | frag = ((frag + _dictionary->sum_of_squared_block_sizes()) / |
duke@435 | 2155 | (totFree * totFree)); |
duke@435 | 2156 | frag = (double)1.0 - frag; |
duke@435 | 2157 | } else { |
duke@435 | 2158 | assert(frag == 0.0, "Follows from totFree == 0"); |
duke@435 | 2159 | } |
duke@435 | 2160 | return frag; |
duke@435 | 2161 | } |
duke@435 | 2162 | |
duke@435 | 2163 | void CompactibleFreeListSpace::beginSweepFLCensus( |
duke@435 | 2164 | float inter_sweep_current, |
ysr@1580 | 2165 | float inter_sweep_estimate, |
ysr@1580 | 2166 | float intra_sweep_estimate) { |
duke@435 | 2167 | assert_locked(); |
duke@435 | 2168 | size_t i; |
duke@435 | 2169 | for (i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 2170 | FreeList* fl = &_indexedFreeList[i]; |
ysr@1580 | 2171 | if (PrintFLSStatistics > 1) { |
ysr@1580 | 2172 | gclog_or_tty->print("size[%d] : ", i); |
ysr@1580 | 2173 | } |
ysr@1580 | 2174 | fl->compute_desired(inter_sweep_current, inter_sweep_estimate, intra_sweep_estimate); |
ysr@1580 | 2175 | fl->set_coalDesired((ssize_t)((double)fl->desired() * CMSSmallCoalSurplusPercent)); |
duke@435 | 2176 | fl->set_beforeSweep(fl->count()); |
duke@435 | 2177 | fl->set_bfrSurp(fl->surplus()); |
duke@435 | 2178 | } |
ysr@1580 | 2179 | _dictionary->beginSweepDictCensus(CMSLargeCoalSurplusPercent, |
duke@435 | 2180 | inter_sweep_current, |
ysr@1580 | 2181 | inter_sweep_estimate, |
ysr@1580 | 2182 | intra_sweep_estimate); |
duke@435 | 2183 | } |
duke@435 | 2184 | |
duke@435 | 2185 | void CompactibleFreeListSpace::setFLSurplus() { |
duke@435 | 2186 | assert_locked(); |
duke@435 | 2187 | size_t i; |
duke@435 | 2188 | for (i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 2189 | FreeList *fl = &_indexedFreeList[i]; |
duke@435 | 2190 | fl->set_surplus(fl->count() - |
ysr@1580 | 2191 | (ssize_t)((double)fl->desired() * CMSSmallSplitSurplusPercent)); |
duke@435 | 2192 | } |
duke@435 | 2193 | } |
duke@435 | 2194 | |
duke@435 | 2195 | void CompactibleFreeListSpace::setFLHints() { |
duke@435 | 2196 | assert_locked(); |
duke@435 | 2197 | size_t i; |
duke@435 | 2198 | size_t h = IndexSetSize; |
duke@435 | 2199 | for (i = IndexSetSize - 1; i != 0; i -= IndexSetStride) { |
duke@435 | 2200 | FreeList *fl = &_indexedFreeList[i]; |
duke@435 | 2201 | fl->set_hint(h); |
duke@435 | 2202 | if (fl->surplus() > 0) { |
duke@435 | 2203 | h = i; |
duke@435 | 2204 | } |
duke@435 | 2205 | } |
duke@435 | 2206 | } |
duke@435 | 2207 | |
duke@435 | 2208 | void CompactibleFreeListSpace::clearFLCensus() { |
duke@435 | 2209 | assert_locked(); |
ysr@3264 | 2210 | size_t i; |
duke@435 | 2211 | for (i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 2212 | FreeList *fl = &_indexedFreeList[i]; |
duke@435 | 2213 | fl->set_prevSweep(fl->count()); |
duke@435 | 2214 | fl->set_coalBirths(0); |
duke@435 | 2215 | fl->set_coalDeaths(0); |
duke@435 | 2216 | fl->set_splitBirths(0); |
duke@435 | 2217 | fl->set_splitDeaths(0); |
duke@435 | 2218 | } |
duke@435 | 2219 | } |
duke@435 | 2220 | |
ysr@447 | 2221 | void CompactibleFreeListSpace::endSweepFLCensus(size_t sweep_count) { |
ysr@1580 | 2222 | if (PrintFLSStatistics > 0) { |
ysr@1580 | 2223 | HeapWord* largestAddr = (HeapWord*) dictionary()->findLargestDict(); |
ysr@1580 | 2224 | gclog_or_tty->print_cr("CMS: Large block " PTR_FORMAT, |
ysr@1580 | 2225 | largestAddr); |
ysr@1580 | 2226 | } |
duke@435 | 2227 | setFLSurplus(); |
duke@435 | 2228 | setFLHints(); |
duke@435 | 2229 | if (PrintGC && PrintFLSCensus > 0) { |
ysr@447 | 2230 | printFLCensus(sweep_count); |
duke@435 | 2231 | } |
duke@435 | 2232 | clearFLCensus(); |
duke@435 | 2233 | assert_locked(); |
ysr@1580 | 2234 | _dictionary->endSweepDictCensus(CMSLargeSplitSurplusPercent); |
duke@435 | 2235 | } |
duke@435 | 2236 | |
duke@435 | 2237 | bool CompactibleFreeListSpace::coalOverPopulated(size_t size) { |
duke@435 | 2238 | if (size < SmallForDictionary) { |
duke@435 | 2239 | FreeList *fl = &_indexedFreeList[size]; |
duke@435 | 2240 | return (fl->coalDesired() < 0) || |
duke@435 | 2241 | ((int)fl->count() > fl->coalDesired()); |
duke@435 | 2242 | } else { |
duke@435 | 2243 | return dictionary()->coalDictOverPopulated(size); |
duke@435 | 2244 | } |
duke@435 | 2245 | } |
duke@435 | 2246 | |
duke@435 | 2247 | void CompactibleFreeListSpace::smallCoalBirth(size_t size) { |
duke@435 | 2248 | assert(size < SmallForDictionary, "Size too large for indexed list"); |
duke@435 | 2249 | FreeList *fl = &_indexedFreeList[size]; |
duke@435 | 2250 | fl->increment_coalBirths(); |
duke@435 | 2251 | fl->increment_surplus(); |
duke@435 | 2252 | } |
duke@435 | 2253 | |
duke@435 | 2254 | void CompactibleFreeListSpace::smallCoalDeath(size_t size) { |
duke@435 | 2255 | assert(size < SmallForDictionary, "Size too large for indexed list"); |
duke@435 | 2256 | FreeList *fl = &_indexedFreeList[size]; |
duke@435 | 2257 | fl->increment_coalDeaths(); |
duke@435 | 2258 | fl->decrement_surplus(); |
duke@435 | 2259 | } |
duke@435 | 2260 | |
duke@435 | 2261 | void CompactibleFreeListSpace::coalBirth(size_t size) { |
duke@435 | 2262 | if (size < SmallForDictionary) { |
duke@435 | 2263 | smallCoalBirth(size); |
duke@435 | 2264 | } else { |
duke@435 | 2265 | dictionary()->dictCensusUpdate(size, |
duke@435 | 2266 | false /* split */, |
duke@435 | 2267 | true /* birth */); |
duke@435 | 2268 | } |
duke@435 | 2269 | } |
duke@435 | 2270 | |
duke@435 | 2271 | void CompactibleFreeListSpace::coalDeath(size_t size) { |
duke@435 | 2272 | if(size < SmallForDictionary) { |
duke@435 | 2273 | smallCoalDeath(size); |
duke@435 | 2274 | } else { |
duke@435 | 2275 | dictionary()->dictCensusUpdate(size, |
duke@435 | 2276 | false /* split */, |
duke@435 | 2277 | false /* birth */); |
duke@435 | 2278 | } |
duke@435 | 2279 | } |
duke@435 | 2280 | |
duke@435 | 2281 | void CompactibleFreeListSpace::smallSplitBirth(size_t size) { |
duke@435 | 2282 | assert(size < SmallForDictionary, "Size too large for indexed list"); |
duke@435 | 2283 | FreeList *fl = &_indexedFreeList[size]; |
duke@435 | 2284 | fl->increment_splitBirths(); |
duke@435 | 2285 | fl->increment_surplus(); |
duke@435 | 2286 | } |
duke@435 | 2287 | |
duke@435 | 2288 | void CompactibleFreeListSpace::smallSplitDeath(size_t size) { |
duke@435 | 2289 | assert(size < SmallForDictionary, "Size too large for indexed list"); |
duke@435 | 2290 | FreeList *fl = &_indexedFreeList[size]; |
duke@435 | 2291 | fl->increment_splitDeaths(); |
duke@435 | 2292 | fl->decrement_surplus(); |
duke@435 | 2293 | } |
duke@435 | 2294 | |
duke@435 | 2295 | void CompactibleFreeListSpace::splitBirth(size_t size) { |
duke@435 | 2296 | if (size < SmallForDictionary) { |
duke@435 | 2297 | smallSplitBirth(size); |
duke@435 | 2298 | } else { |
duke@435 | 2299 | dictionary()->dictCensusUpdate(size, |
duke@435 | 2300 | true /* split */, |
duke@435 | 2301 | true /* birth */); |
duke@435 | 2302 | } |
duke@435 | 2303 | } |
duke@435 | 2304 | |
duke@435 | 2305 | void CompactibleFreeListSpace::splitDeath(size_t size) { |
duke@435 | 2306 | if (size < SmallForDictionary) { |
duke@435 | 2307 | smallSplitDeath(size); |
duke@435 | 2308 | } else { |
duke@435 | 2309 | dictionary()->dictCensusUpdate(size, |
duke@435 | 2310 | true /* split */, |
duke@435 | 2311 | false /* birth */); |
duke@435 | 2312 | } |
duke@435 | 2313 | } |
duke@435 | 2314 | |
duke@435 | 2315 | void CompactibleFreeListSpace::split(size_t from, size_t to1) { |
duke@435 | 2316 | size_t to2 = from - to1; |
duke@435 | 2317 | splitDeath(from); |
duke@435 | 2318 | splitBirth(to1); |
duke@435 | 2319 | splitBirth(to2); |
duke@435 | 2320 | } |
duke@435 | 2321 | |
duke@435 | 2322 | void CompactibleFreeListSpace::print() const { |
ysr@2294 | 2323 | print_on(tty); |
duke@435 | 2324 | } |
duke@435 | 2325 | |
duke@435 | 2326 | void CompactibleFreeListSpace::prepare_for_verify() { |
duke@435 | 2327 | assert_locked(); |
duke@435 | 2328 | repairLinearAllocationBlocks(); |
duke@435 | 2329 | // Verify that the SpoolBlocks look like free blocks of |
duke@435 | 2330 | // appropriate sizes... To be done ... |
duke@435 | 2331 | } |
duke@435 | 2332 | |
duke@435 | 2333 | class VerifyAllBlksClosure: public BlkClosure { |
coleenp@548 | 2334 | private: |
duke@435 | 2335 | const CompactibleFreeListSpace* _sp; |
duke@435 | 2336 | const MemRegion _span; |
ysr@2071 | 2337 | HeapWord* _last_addr; |
ysr@2071 | 2338 | size_t _last_size; |
ysr@2071 | 2339 | bool _last_was_obj; |
ysr@2071 | 2340 | bool _last_was_live; |
duke@435 | 2341 | |
duke@435 | 2342 | public: |
duke@435 | 2343 | VerifyAllBlksClosure(const CompactibleFreeListSpace* sp, |
ysr@2071 | 2344 | MemRegion span) : _sp(sp), _span(span), |
ysr@2071 | 2345 | _last_addr(NULL), _last_size(0), |
ysr@2071 | 2346 | _last_was_obj(false), _last_was_live(false) { } |
duke@435 | 2347 | |
coleenp@548 | 2348 | virtual size_t do_blk(HeapWord* addr) { |
duke@435 | 2349 | size_t res; |
ysr@2071 | 2350 | bool was_obj = false; |
ysr@2071 | 2351 | bool was_live = false; |
duke@435 | 2352 | if (_sp->block_is_obj(addr)) { |
ysr@2071 | 2353 | was_obj = true; |
duke@435 | 2354 | oop p = oop(addr); |
duke@435 | 2355 | guarantee(p->is_oop(), "Should be an oop"); |
duke@435 | 2356 | res = _sp->adjustObjectSize(p->size()); |
duke@435 | 2357 | if (_sp->obj_is_alive(addr)) { |
ysr@2071 | 2358 | was_live = true; |
duke@435 | 2359 | p->verify(); |
duke@435 | 2360 | } |
duke@435 | 2361 | } else { |
duke@435 | 2362 | FreeChunk* fc = (FreeChunk*)addr; |
duke@435 | 2363 | res = fc->size(); |
duke@435 | 2364 | if (FLSVerifyLists && !fc->cantCoalesce()) { |
duke@435 | 2365 | guarantee(_sp->verifyChunkInFreeLists(fc), |
duke@435 | 2366 | "Chunk should be on a free list"); |
duke@435 | 2367 | } |
duke@435 | 2368 | } |
ysr@2071 | 2369 | if (res == 0) { |
ysr@2071 | 2370 | gclog_or_tty->print_cr("Livelock: no rank reduction!"); |
ysr@2071 | 2371 | gclog_or_tty->print_cr( |
ysr@2071 | 2372 | " Current: addr = " PTR_FORMAT ", size = " SIZE_FORMAT ", obj = %s, live = %s \n" |
ysr@2071 | 2373 | " Previous: addr = " PTR_FORMAT ", size = " SIZE_FORMAT ", obj = %s, live = %s \n", |
ysr@2071 | 2374 | addr, res, was_obj ?"true":"false", was_live ?"true":"false", |
ysr@2071 | 2375 | _last_addr, _last_size, _last_was_obj?"true":"false", _last_was_live?"true":"false"); |
ysr@2071 | 2376 | _sp->print_on(gclog_or_tty); |
ysr@2071 | 2377 | guarantee(false, "Seppuku!"); |
ysr@2071 | 2378 | } |
ysr@2071 | 2379 | _last_addr = addr; |
ysr@2071 | 2380 | _last_size = res; |
ysr@2071 | 2381 | _last_was_obj = was_obj; |
ysr@2071 | 2382 | _last_was_live = was_live; |
duke@435 | 2383 | return res; |
duke@435 | 2384 | } |
duke@435 | 2385 | }; |
duke@435 | 2386 | |
duke@435 | 2387 | class VerifyAllOopsClosure: public OopClosure { |
coleenp@548 | 2388 | private: |
duke@435 | 2389 | const CMSCollector* _collector; |
duke@435 | 2390 | const CompactibleFreeListSpace* _sp; |
duke@435 | 2391 | const MemRegion _span; |
duke@435 | 2392 | const bool _past_remark; |
duke@435 | 2393 | const CMSBitMap* _bit_map; |
duke@435 | 2394 | |
coleenp@548 | 2395 | protected: |
coleenp@548 | 2396 | void do_oop(void* p, oop obj) { |
coleenp@548 | 2397 | if (_span.contains(obj)) { // the interior oop points into CMS heap |
coleenp@548 | 2398 | if (!_span.contains(p)) { // reference from outside CMS heap |
coleenp@548 | 2399 | // Should be a valid object; the first disjunct below allows |
coleenp@548 | 2400 | // us to sidestep an assertion in block_is_obj() that insists |
coleenp@548 | 2401 | // that p be in _sp. Note that several generations (and spaces) |
coleenp@548 | 2402 | // are spanned by _span (CMS heap) above. |
coleenp@548 | 2403 | guarantee(!_sp->is_in_reserved(obj) || |
coleenp@548 | 2404 | _sp->block_is_obj((HeapWord*)obj), |
coleenp@548 | 2405 | "Should be an object"); |
coleenp@548 | 2406 | guarantee(obj->is_oop(), "Should be an oop"); |
coleenp@548 | 2407 | obj->verify(); |
coleenp@548 | 2408 | if (_past_remark) { |
coleenp@548 | 2409 | // Remark has been completed, the object should be marked |
coleenp@548 | 2410 | _bit_map->isMarked((HeapWord*)obj); |
coleenp@548 | 2411 | } |
coleenp@548 | 2412 | } else { // reference within CMS heap |
coleenp@548 | 2413 | if (_past_remark) { |
coleenp@548 | 2414 | // Remark has been completed -- so the referent should have |
coleenp@548 | 2415 | // been marked, if referring object is. |
coleenp@548 | 2416 | if (_bit_map->isMarked(_collector->block_start(p))) { |
coleenp@548 | 2417 | guarantee(_bit_map->isMarked((HeapWord*)obj), "Marking error?"); |
coleenp@548 | 2418 | } |
coleenp@548 | 2419 | } |
coleenp@548 | 2420 | } |
coleenp@548 | 2421 | } else if (_sp->is_in_reserved(p)) { |
coleenp@548 | 2422 | // the reference is from FLS, and points out of FLS |
coleenp@548 | 2423 | guarantee(obj->is_oop(), "Should be an oop"); |
coleenp@548 | 2424 | obj->verify(); |
coleenp@548 | 2425 | } |
coleenp@548 | 2426 | } |
coleenp@548 | 2427 | |
coleenp@548 | 2428 | template <class T> void do_oop_work(T* p) { |
coleenp@548 | 2429 | T heap_oop = oopDesc::load_heap_oop(p); |
coleenp@548 | 2430 | if (!oopDesc::is_null(heap_oop)) { |
coleenp@548 | 2431 | oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); |
coleenp@548 | 2432 | do_oop(p, obj); |
coleenp@548 | 2433 | } |
coleenp@548 | 2434 | } |
coleenp@548 | 2435 | |
duke@435 | 2436 | public: |
duke@435 | 2437 | VerifyAllOopsClosure(const CMSCollector* collector, |
duke@435 | 2438 | const CompactibleFreeListSpace* sp, MemRegion span, |
duke@435 | 2439 | bool past_remark, CMSBitMap* bit_map) : |
duke@435 | 2440 | OopClosure(), _collector(collector), _sp(sp), _span(span), |
duke@435 | 2441 | _past_remark(past_remark), _bit_map(bit_map) { } |
duke@435 | 2442 | |
coleenp@548 | 2443 | virtual void do_oop(oop* p) { VerifyAllOopsClosure::do_oop_work(p); } |
coleenp@548 | 2444 | virtual void do_oop(narrowOop* p) { VerifyAllOopsClosure::do_oop_work(p); } |
duke@435 | 2445 | }; |
duke@435 | 2446 | |
brutisso@3711 | 2447 | void CompactibleFreeListSpace::verify() const { |
duke@435 | 2448 | assert_lock_strong(&_freelistLock); |
duke@435 | 2449 | verify_objects_initialized(); |
duke@435 | 2450 | MemRegion span = _collector->_span; |
duke@435 | 2451 | bool past_remark = (_collector->abstract_state() == |
duke@435 | 2452 | CMSCollector::Sweeping); |
duke@435 | 2453 | |
duke@435 | 2454 | ResourceMark rm; |
duke@435 | 2455 | HandleMark hm; |
duke@435 | 2456 | |
duke@435 | 2457 | // Check integrity of CFL data structures |
duke@435 | 2458 | _promoInfo.verify(); |
duke@435 | 2459 | _dictionary->verify(); |
duke@435 | 2460 | if (FLSVerifyIndexTable) { |
duke@435 | 2461 | verifyIndexedFreeLists(); |
duke@435 | 2462 | } |
duke@435 | 2463 | // Check integrity of all objects and free blocks in space |
duke@435 | 2464 | { |
duke@435 | 2465 | VerifyAllBlksClosure cl(this, span); |
duke@435 | 2466 | ((CompactibleFreeListSpace*)this)->blk_iterate(&cl); // cast off const |
duke@435 | 2467 | } |
duke@435 | 2468 | // Check that all references in the heap to FLS |
duke@435 | 2469 | // are to valid objects in FLS or that references in |
duke@435 | 2470 | // FLS are to valid objects elsewhere in the heap |
duke@435 | 2471 | if (FLSVerifyAllHeapReferences) |
duke@435 | 2472 | { |
duke@435 | 2473 | VerifyAllOopsClosure cl(_collector, this, span, past_remark, |
duke@435 | 2474 | _collector->markBitMap()); |
duke@435 | 2475 | CollectedHeap* ch = Universe::heap(); |
duke@435 | 2476 | ch->oop_iterate(&cl); // all oops in generations |
duke@435 | 2477 | ch->permanent_oop_iterate(&cl); // all oops in perm gen |
duke@435 | 2478 | } |
duke@435 | 2479 | |
duke@435 | 2480 | if (VerifyObjectStartArray) { |
duke@435 | 2481 | // Verify the block offset table |
duke@435 | 2482 | _bt.verify(); |
duke@435 | 2483 | } |
duke@435 | 2484 | } |
duke@435 | 2485 | |
duke@435 | 2486 | #ifndef PRODUCT |
duke@435 | 2487 | void CompactibleFreeListSpace::verifyFreeLists() const { |
duke@435 | 2488 | if (FLSVerifyLists) { |
duke@435 | 2489 | _dictionary->verify(); |
duke@435 | 2490 | verifyIndexedFreeLists(); |
duke@435 | 2491 | } else { |
duke@435 | 2492 | if (FLSVerifyDictionary) { |
duke@435 | 2493 | _dictionary->verify(); |
duke@435 | 2494 | } |
duke@435 | 2495 | if (FLSVerifyIndexTable) { |
duke@435 | 2496 | verifyIndexedFreeLists(); |
duke@435 | 2497 | } |
duke@435 | 2498 | } |
duke@435 | 2499 | } |
duke@435 | 2500 | #endif |
duke@435 | 2501 | |
duke@435 | 2502 | void CompactibleFreeListSpace::verifyIndexedFreeLists() const { |
duke@435 | 2503 | size_t i = 0; |
ysr@3264 | 2504 | for (; i < IndexSetStart; i++) { |
duke@435 | 2505 | guarantee(_indexedFreeList[i].head() == NULL, "should be NULL"); |
duke@435 | 2506 | } |
duke@435 | 2507 | for (; i < IndexSetSize; i++) { |
duke@435 | 2508 | verifyIndexedFreeList(i); |
duke@435 | 2509 | } |
duke@435 | 2510 | } |
duke@435 | 2511 | |
duke@435 | 2512 | void CompactibleFreeListSpace::verifyIndexedFreeList(size_t size) const { |
ysr@1580 | 2513 | FreeChunk* fc = _indexedFreeList[size].head(); |
ysr@1580 | 2514 | FreeChunk* tail = _indexedFreeList[size].tail(); |
ysr@1580 | 2515 | size_t num = _indexedFreeList[size].count(); |
ysr@1580 | 2516 | size_t n = 0; |
ysr@3264 | 2517 | guarantee(((size >= IndexSetStart) && (size % IndexSetStride == 0)) || fc == NULL, |
ysr@3220 | 2518 | "Slot should have been empty"); |
ysr@1580 | 2519 | for (; fc != NULL; fc = fc->next(), n++) { |
duke@435 | 2520 | guarantee(fc->size() == size, "Size inconsistency"); |
duke@435 | 2521 | guarantee(fc->isFree(), "!free?"); |
duke@435 | 2522 | guarantee(fc->next() == NULL || fc->next()->prev() == fc, "Broken list"); |
ysr@1580 | 2523 | guarantee((fc->next() == NULL) == (fc == tail), "Incorrect tail"); |
duke@435 | 2524 | } |
ysr@1580 | 2525 | guarantee(n == num, "Incorrect count"); |
duke@435 | 2526 | } |
duke@435 | 2527 | |
duke@435 | 2528 | #ifndef PRODUCT |
ysr@3220 | 2529 | void CompactibleFreeListSpace::check_free_list_consistency() const { |
duke@435 | 2530 | assert(_dictionary->minSize() <= IndexSetSize, |
duke@435 | 2531 | "Some sizes can't be allocated without recourse to" |
duke@435 | 2532 | " linear allocation buffers"); |
duke@435 | 2533 | assert(MIN_TREE_CHUNK_SIZE*HeapWordSize == sizeof(TreeChunk), |
duke@435 | 2534 | "else MIN_TREE_CHUNK_SIZE is wrong"); |
ysr@3220 | 2535 | assert((IndexSetStride == 2 && IndexSetStart == 4) || // 32-bit |
ysr@3220 | 2536 | (IndexSetStride == 1 && IndexSetStart == 3), "just checking"); // 64-bit |
ysr@3264 | 2537 | assert((IndexSetStride != 2) || (IndexSetStart % 2 == 0), |
duke@435 | 2538 | "Some for-loops may be incorrectly initialized"); |
duke@435 | 2539 | assert((IndexSetStride != 2) || (IndexSetSize % 2 == 1), |
duke@435 | 2540 | "For-loops that iterate over IndexSet with stride 2 may be wrong"); |
duke@435 | 2541 | } |
duke@435 | 2542 | #endif |
duke@435 | 2543 | |
ysr@447 | 2544 | void CompactibleFreeListSpace::printFLCensus(size_t sweep_count) const { |
duke@435 | 2545 | assert_lock_strong(&_freelistLock); |
ysr@447 | 2546 | FreeList total; |
ysr@447 | 2547 | gclog_or_tty->print("end sweep# " SIZE_FORMAT "\n", sweep_count); |
ysr@447 | 2548 | FreeList::print_labels_on(gclog_or_tty, "size"); |
duke@435 | 2549 | size_t totalFree = 0; |
duke@435 | 2550 | for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 2551 | const FreeList *fl = &_indexedFreeList[i]; |
ysr@447 | 2552 | totalFree += fl->count() * fl->size(); |
ysr@447 | 2553 | if (i % (40*IndexSetStride) == 0) { |
ysr@447 | 2554 | FreeList::print_labels_on(gclog_or_tty, "size"); |
ysr@447 | 2555 | } |
ysr@447 | 2556 | fl->print_on(gclog_or_tty); |
ysr@447 | 2557 | total.set_bfrSurp( total.bfrSurp() + fl->bfrSurp() ); |
ysr@447 | 2558 | total.set_surplus( total.surplus() + fl->surplus() ); |
ysr@447 | 2559 | total.set_desired( total.desired() + fl->desired() ); |
ysr@447 | 2560 | total.set_prevSweep( total.prevSweep() + fl->prevSweep() ); |
ysr@447 | 2561 | total.set_beforeSweep(total.beforeSweep() + fl->beforeSweep()); |
ysr@447 | 2562 | total.set_count( total.count() + fl->count() ); |
ysr@447 | 2563 | total.set_coalBirths( total.coalBirths() + fl->coalBirths() ); |
ysr@447 | 2564 | total.set_coalDeaths( total.coalDeaths() + fl->coalDeaths() ); |
ysr@447 | 2565 | total.set_splitBirths(total.splitBirths() + fl->splitBirths()); |
ysr@447 | 2566 | total.set_splitDeaths(total.splitDeaths() + fl->splitDeaths()); |
duke@435 | 2567 | } |
ysr@447 | 2568 | total.print_on(gclog_or_tty, "TOTAL"); |
ysr@447 | 2569 | gclog_or_tty->print_cr("Total free in indexed lists " |
ysr@447 | 2570 | SIZE_FORMAT " words", totalFree); |
duke@435 | 2571 | gclog_or_tty->print("growth: %8.5f deficit: %8.5f\n", |
ysr@447 | 2572 | (double)(total.splitBirths()+total.coalBirths()-total.splitDeaths()-total.coalDeaths())/ |
ysr@447 | 2573 | (total.prevSweep() != 0 ? (double)total.prevSweep() : 1.0), |
ysr@447 | 2574 | (double)(total.desired() - total.count())/(total.desired() != 0 ? (double)total.desired() : 1.0)); |
duke@435 | 2575 | _dictionary->printDictCensus(); |
duke@435 | 2576 | } |
duke@435 | 2577 | |
ysr@1580 | 2578 | /////////////////////////////////////////////////////////////////////////// |
ysr@1580 | 2579 | // CFLS_LAB |
ysr@1580 | 2580 | /////////////////////////////////////////////////////////////////////////// |
ysr@1580 | 2581 | |
ysr@1580 | 2582 | #define VECTOR_257(x) \ |
ysr@1580 | 2583 | /* 1 2 3 4 5 6 7 8 9 1x 11 12 13 14 15 16 17 18 19 2x 21 22 23 24 25 26 27 28 29 3x 31 32 */ \ |
ysr@1580 | 2584 | { x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, \ |
ysr@1580 | 2585 | x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, \ |
ysr@1580 | 2586 | x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, \ |
ysr@1580 | 2587 | x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, \ |
ysr@1580 | 2588 | x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, \ |
ysr@1580 | 2589 | x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, \ |
ysr@1580 | 2590 | x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, \ |
ysr@1580 | 2591 | x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, \ |
ysr@1580 | 2592 | x } |
ysr@1580 | 2593 | |
ysr@1580 | 2594 | // Initialize with default setting of CMSParPromoteBlocksToClaim, _not_ |
ysr@1580 | 2595 | // OldPLABSize, whose static default is different; if overridden at the |
ysr@1580 | 2596 | // command-line, this will get reinitialized via a call to |
ysr@1580 | 2597 | // modify_initialization() below. |
ysr@1580 | 2598 | AdaptiveWeightedAverage CFLS_LAB::_blocks_to_claim[] = |
ysr@1580 | 2599 | VECTOR_257(AdaptiveWeightedAverage(OldPLABWeight, (float)CMSParPromoteBlocksToClaim)); |
ysr@1580 | 2600 | size_t CFLS_LAB::_global_num_blocks[] = VECTOR_257(0); |
jmasa@3357 | 2601 | uint CFLS_LAB::_global_num_workers[] = VECTOR_257(0); |
duke@435 | 2602 | |
duke@435 | 2603 | CFLS_LAB::CFLS_LAB(CompactibleFreeListSpace* cfls) : |
duke@435 | 2604 | _cfls(cfls) |
duke@435 | 2605 | { |
ysr@1580 | 2606 | assert(CompactibleFreeListSpace::IndexSetSize == 257, "Modify VECTOR_257() macro above"); |
duke@435 | 2607 | for (size_t i = CompactibleFreeListSpace::IndexSetStart; |
duke@435 | 2608 | i < CompactibleFreeListSpace::IndexSetSize; |
duke@435 | 2609 | i += CompactibleFreeListSpace::IndexSetStride) { |
duke@435 | 2610 | _indexedFreeList[i].set_size(i); |
ysr@1580 | 2611 | _num_blocks[i] = 0; |
ysr@1580 | 2612 | } |
ysr@1580 | 2613 | } |
ysr@1580 | 2614 | |
ysr@1580 | 2615 | static bool _CFLS_LAB_modified = false; |
ysr@1580 | 2616 | |
ysr@1580 | 2617 | void CFLS_LAB::modify_initialization(size_t n, unsigned wt) { |
ysr@1580 | 2618 | assert(!_CFLS_LAB_modified, "Call only once"); |
ysr@1580 | 2619 | _CFLS_LAB_modified = true; |
ysr@1580 | 2620 | for (size_t i = CompactibleFreeListSpace::IndexSetStart; |
ysr@1580 | 2621 | i < CompactibleFreeListSpace::IndexSetSize; |
ysr@1580 | 2622 | i += CompactibleFreeListSpace::IndexSetStride) { |
ysr@1580 | 2623 | _blocks_to_claim[i].modify(n, wt, true /* force */); |
duke@435 | 2624 | } |
duke@435 | 2625 | } |
duke@435 | 2626 | |
duke@435 | 2627 | HeapWord* CFLS_LAB::alloc(size_t word_sz) { |
duke@435 | 2628 | FreeChunk* res; |
ysr@2132 | 2629 | assert(word_sz == _cfls->adjustObjectSize(word_sz), "Error"); |
duke@435 | 2630 | if (word_sz >= CompactibleFreeListSpace::IndexSetSize) { |
duke@435 | 2631 | // This locking manages sync with other large object allocations. |
duke@435 | 2632 | MutexLockerEx x(_cfls->parDictionaryAllocLock(), |
duke@435 | 2633 | Mutex::_no_safepoint_check_flag); |
duke@435 | 2634 | res = _cfls->getChunkFromDictionaryExact(word_sz); |
duke@435 | 2635 | if (res == NULL) return NULL; |
duke@435 | 2636 | } else { |
duke@435 | 2637 | FreeList* fl = &_indexedFreeList[word_sz]; |
duke@435 | 2638 | if (fl->count() == 0) { |
duke@435 | 2639 | // Attempt to refill this local free list. |
ysr@1580 | 2640 | get_from_global_pool(word_sz, fl); |
duke@435 | 2641 | // If it didn't work, give up. |
duke@435 | 2642 | if (fl->count() == 0) return NULL; |
duke@435 | 2643 | } |
duke@435 | 2644 | res = fl->getChunkAtHead(); |
duke@435 | 2645 | assert(res != NULL, "Why was count non-zero?"); |
duke@435 | 2646 | } |
duke@435 | 2647 | res->markNotFree(); |
duke@435 | 2648 | assert(!res->isFree(), "shouldn't be marked free"); |
coleenp@622 | 2649 | assert(oop(res)->klass_or_null() == NULL, "should look uninitialized"); |
duke@435 | 2650 | // mangle a just allocated object with a distinct pattern. |
duke@435 | 2651 | debug_only(res->mangleAllocated(word_sz)); |
duke@435 | 2652 | return (HeapWord*)res; |
duke@435 | 2653 | } |
duke@435 | 2654 | |
ysr@1580 | 2655 | // Get a chunk of blocks of the right size and update related |
ysr@1580 | 2656 | // book-keeping stats |
ysr@1580 | 2657 | void CFLS_LAB::get_from_global_pool(size_t word_sz, FreeList* fl) { |
ysr@1580 | 2658 | // Get the #blocks we want to claim |
ysr@1580 | 2659 | size_t n_blks = (size_t)_blocks_to_claim[word_sz].average(); |
ysr@1580 | 2660 | assert(n_blks > 0, "Error"); |
ysr@1580 | 2661 | assert(ResizePLAB || n_blks == OldPLABSize, "Error"); |
ysr@1580 | 2662 | // In some cases, when the application has a phase change, |
ysr@1580 | 2663 | // there may be a sudden and sharp shift in the object survival |
ysr@1580 | 2664 | // profile, and updating the counts at the end of a scavenge |
ysr@1580 | 2665 | // may not be quick enough, giving rise to large scavenge pauses |
ysr@1580 | 2666 | // during these phase changes. It is beneficial to detect such |
ysr@1580 | 2667 | // changes on-the-fly during a scavenge and avoid such a phase-change |
ysr@1580 | 2668 | // pothole. The following code is a heuristic attempt to do that. |
ysr@1580 | 2669 | // It is protected by a product flag until we have gained |
ysr@1580 | 2670 | // enough experience with this heuristic and fine-tuned its behaviour. |
ysr@1580 | 2671 | // WARNING: This might increase fragmentation if we overreact to |
ysr@1580 | 2672 | // small spikes, so some kind of historical smoothing based on |
ysr@1580 | 2673 | // previous experience with the greater reactivity might be useful. |
ysr@1580 | 2674 | // Lacking sufficient experience, CMSOldPLABResizeQuicker is disabled by |
ysr@1580 | 2675 | // default. |
ysr@1580 | 2676 | if (ResizeOldPLAB && CMSOldPLABResizeQuicker) { |
ysr@1580 | 2677 | size_t multiple = _num_blocks[word_sz]/(CMSOldPLABToleranceFactor*CMSOldPLABNumRefills*n_blks); |
ysr@1580 | 2678 | n_blks += CMSOldPLABReactivityFactor*multiple*n_blks; |
ysr@1580 | 2679 | n_blks = MIN2(n_blks, CMSOldPLABMax); |
ysr@1580 | 2680 | } |
ysr@1580 | 2681 | assert(n_blks > 0, "Error"); |
ysr@1580 | 2682 | _cfls->par_get_chunk_of_blocks(word_sz, n_blks, fl); |
ysr@1580 | 2683 | // Update stats table entry for this block size |
ysr@1580 | 2684 | _num_blocks[word_sz] += fl->count(); |
ysr@1580 | 2685 | } |
ysr@1580 | 2686 | |
ysr@1580 | 2687 | void CFLS_LAB::compute_desired_plab_size() { |
ysr@1580 | 2688 | for (size_t i = CompactibleFreeListSpace::IndexSetStart; |
duke@435 | 2689 | i < CompactibleFreeListSpace::IndexSetSize; |
duke@435 | 2690 | i += CompactibleFreeListSpace::IndexSetStride) { |
ysr@1580 | 2691 | assert((_global_num_workers[i] == 0) == (_global_num_blocks[i] == 0), |
ysr@1580 | 2692 | "Counter inconsistency"); |
ysr@1580 | 2693 | if (_global_num_workers[i] > 0) { |
ysr@1580 | 2694 | // Need to smooth wrt historical average |
ysr@1580 | 2695 | if (ResizeOldPLAB) { |
ysr@1580 | 2696 | _blocks_to_claim[i].sample( |
ysr@1580 | 2697 | MAX2((size_t)CMSOldPLABMin, |
ysr@1580 | 2698 | MIN2((size_t)CMSOldPLABMax, |
ysr@1580 | 2699 | _global_num_blocks[i]/(_global_num_workers[i]*CMSOldPLABNumRefills)))); |
ysr@1580 | 2700 | } |
ysr@1580 | 2701 | // Reset counters for next round |
ysr@1580 | 2702 | _global_num_workers[i] = 0; |
ysr@1580 | 2703 | _global_num_blocks[i] = 0; |
ysr@1580 | 2704 | if (PrintOldPLAB) { |
ysr@1580 | 2705 | gclog_or_tty->print_cr("[%d]: %d", i, (size_t)_blocks_to_claim[i].average()); |
ysr@1580 | 2706 | } |
duke@435 | 2707 | } |
duke@435 | 2708 | } |
duke@435 | 2709 | } |
duke@435 | 2710 | |
ysr@3220 | 2711 | // If this is changed in the future to allow parallel |
ysr@3220 | 2712 | // access, one would need to take the FL locks and, |
ysr@3220 | 2713 | // depending on how it is used, stagger access from |
ysr@3220 | 2714 | // parallel threads to reduce contention. |
ysr@1580 | 2715 | void CFLS_LAB::retire(int tid) { |
ysr@1580 | 2716 | // We run this single threaded with the world stopped; |
ysr@1580 | 2717 | // so no need for locks and such. |
ysr@1580 | 2718 | NOT_PRODUCT(Thread* t = Thread::current();) |
ysr@1580 | 2719 | assert(Thread::current()->is_VM_thread(), "Error"); |
ysr@1580 | 2720 | for (size_t i = CompactibleFreeListSpace::IndexSetStart; |
ysr@1580 | 2721 | i < CompactibleFreeListSpace::IndexSetSize; |
ysr@1580 | 2722 | i += CompactibleFreeListSpace::IndexSetStride) { |
ysr@1580 | 2723 | assert(_num_blocks[i] >= (size_t)_indexedFreeList[i].count(), |
ysr@1580 | 2724 | "Can't retire more than what we obtained"); |
ysr@1580 | 2725 | if (_num_blocks[i] > 0) { |
ysr@1580 | 2726 | size_t num_retire = _indexedFreeList[i].count(); |
ysr@1580 | 2727 | assert(_num_blocks[i] > num_retire, "Should have used at least one"); |
ysr@1580 | 2728 | { |
ysr@3220 | 2729 | // MutexLockerEx x(_cfls->_indexedFreeListParLocks[i], |
ysr@3220 | 2730 | // Mutex::_no_safepoint_check_flag); |
ysr@3220 | 2731 | |
ysr@1580 | 2732 | // Update globals stats for num_blocks used |
ysr@1580 | 2733 | _global_num_blocks[i] += (_num_blocks[i] - num_retire); |
ysr@1580 | 2734 | _global_num_workers[i]++; |
jmasa@3357 | 2735 | assert(_global_num_workers[i] <= ParallelGCThreads, "Too big"); |
ysr@1580 | 2736 | if (num_retire > 0) { |
ysr@1580 | 2737 | _cfls->_indexedFreeList[i].prepend(&_indexedFreeList[i]); |
ysr@1580 | 2738 | // Reset this list. |
ysr@1580 | 2739 | _indexedFreeList[i] = FreeList(); |
ysr@1580 | 2740 | _indexedFreeList[i].set_size(i); |
ysr@1580 | 2741 | } |
ysr@1580 | 2742 | } |
ysr@1580 | 2743 | if (PrintOldPLAB) { |
ysr@1580 | 2744 | gclog_or_tty->print_cr("%d[%d]: %d/%d/%d", |
ysr@1580 | 2745 | tid, i, num_retire, _num_blocks[i], (size_t)_blocks_to_claim[i].average()); |
ysr@1580 | 2746 | } |
ysr@1580 | 2747 | // Reset stats for next round |
ysr@1580 | 2748 | _num_blocks[i] = 0; |
ysr@1580 | 2749 | } |
ysr@1580 | 2750 | } |
ysr@1580 | 2751 | } |
ysr@1580 | 2752 | |
ysr@1580 | 2753 | void CompactibleFreeListSpace:: par_get_chunk_of_blocks(size_t word_sz, size_t n, FreeList* fl) { |
duke@435 | 2754 | assert(fl->count() == 0, "Precondition."); |
duke@435 | 2755 | assert(word_sz < CompactibleFreeListSpace::IndexSetSize, |
duke@435 | 2756 | "Precondition"); |
duke@435 | 2757 | |
ysr@1580 | 2758 | // We'll try all multiples of word_sz in the indexed set, starting with |
ysr@1580 | 2759 | // word_sz itself and, if CMSSplitIndexedFreeListBlocks, try larger multiples, |
ysr@1580 | 2760 | // then try getting a big chunk and splitting it. |
ysr@1580 | 2761 | { |
ysr@1580 | 2762 | bool found; |
ysr@1580 | 2763 | int k; |
ysr@1580 | 2764 | size_t cur_sz; |
ysr@1580 | 2765 | for (k = 1, cur_sz = k * word_sz, found = false; |
ysr@1580 | 2766 | (cur_sz < CompactibleFreeListSpace::IndexSetSize) && |
ysr@1580 | 2767 | (CMSSplitIndexedFreeListBlocks || k <= 1); |
ysr@1580 | 2768 | k++, cur_sz = k * word_sz) { |
ysr@1580 | 2769 | FreeList fl_for_cur_sz; // Empty. |
ysr@1580 | 2770 | fl_for_cur_sz.set_size(cur_sz); |
ysr@1580 | 2771 | { |
ysr@1580 | 2772 | MutexLockerEx x(_indexedFreeListParLocks[cur_sz], |
ysr@1580 | 2773 | Mutex::_no_safepoint_check_flag); |
ysr@2071 | 2774 | FreeList* gfl = &_indexedFreeList[cur_sz]; |
ysr@1580 | 2775 | if (gfl->count() != 0) { |
ysr@1580 | 2776 | // nn is the number of chunks of size cur_sz that |
ysr@1580 | 2777 | // we'd need to split k-ways each, in order to create |
ysr@1580 | 2778 | // "n" chunks of size word_sz each. |
ysr@1580 | 2779 | const size_t nn = MAX2(n/k, (size_t)1); |
ysr@1580 | 2780 | gfl->getFirstNChunksFromList(nn, &fl_for_cur_sz); |
ysr@1580 | 2781 | found = true; |
ysr@1580 | 2782 | if (k > 1) { |
ysr@1580 | 2783 | // Update split death stats for the cur_sz-size blocks list: |
ysr@1580 | 2784 | // we increment the split death count by the number of blocks |
ysr@1580 | 2785 | // we just took from the cur_sz-size blocks list and which |
ysr@1580 | 2786 | // we will be splitting below. |
ysr@2071 | 2787 | ssize_t deaths = gfl->splitDeaths() + |
ysr@1580 | 2788 | fl_for_cur_sz.count(); |
ysr@2071 | 2789 | gfl->set_splitDeaths(deaths); |
ysr@1580 | 2790 | } |
ysr@1580 | 2791 | } |
ysr@1580 | 2792 | } |
ysr@1580 | 2793 | // Now transfer fl_for_cur_sz to fl. Common case, we hope, is k = 1. |
ysr@1580 | 2794 | if (found) { |
ysr@1580 | 2795 | if (k == 1) { |
ysr@1580 | 2796 | fl->prepend(&fl_for_cur_sz); |
ysr@1580 | 2797 | } else { |
ysr@1580 | 2798 | // Divide each block on fl_for_cur_sz up k ways. |
ysr@1580 | 2799 | FreeChunk* fc; |
ysr@1580 | 2800 | while ((fc = fl_for_cur_sz.getChunkAtHead()) != NULL) { |
ysr@1580 | 2801 | // Must do this in reverse order, so that anybody attempting to |
ysr@1580 | 2802 | // access the main chunk sees it as a single free block until we |
ysr@1580 | 2803 | // change it. |
ysr@1580 | 2804 | size_t fc_size = fc->size(); |
ysr@2071 | 2805 | assert(fc->isFree(), "Error"); |
ysr@1580 | 2806 | for (int i = k-1; i >= 0; i--) { |
ysr@1580 | 2807 | FreeChunk* ffc = (FreeChunk*)((HeapWord*)fc + i * word_sz); |
ysr@2071 | 2808 | assert((i != 0) || |
ysr@2071 | 2809 | ((fc == ffc) && ffc->isFree() && |
ysr@2071 | 2810 | (ffc->size() == k*word_sz) && (fc_size == word_sz)), |
ysr@2071 | 2811 | "Counting error"); |
ysr@1580 | 2812 | ffc->setSize(word_sz); |
ysr@2071 | 2813 | ffc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. |
ysr@1580 | 2814 | ffc->linkNext(NULL); |
ysr@1580 | 2815 | // Above must occur before BOT is updated below. |
ysr@2071 | 2816 | OrderAccess::storestore(); |
ysr@2071 | 2817 | // splitting from the right, fc_size == i * word_sz |
ysr@2071 | 2818 | _bt.mark_block((HeapWord*)ffc, word_sz, true /* reducing */); |
ysr@1580 | 2819 | fc_size -= word_sz; |
ysr@2071 | 2820 | assert(fc_size == i*word_sz, "Error"); |
ysr@2071 | 2821 | _bt.verify_not_unallocated((HeapWord*)ffc, word_sz); |
ysr@1580 | 2822 | _bt.verify_single_block((HeapWord*)fc, fc_size); |
ysr@2071 | 2823 | _bt.verify_single_block((HeapWord*)ffc, word_sz); |
ysr@1580 | 2824 | // Push this on "fl". |
ysr@1580 | 2825 | fl->returnChunkAtHead(ffc); |
ysr@1580 | 2826 | } |
ysr@1580 | 2827 | // TRAP |
ysr@1580 | 2828 | assert(fl->tail()->next() == NULL, "List invariant."); |
ysr@1580 | 2829 | } |
ysr@1580 | 2830 | } |
ysr@1580 | 2831 | // Update birth stats for this block size. |
ysr@1580 | 2832 | size_t num = fl->count(); |
ysr@1580 | 2833 | MutexLockerEx x(_indexedFreeListParLocks[word_sz], |
ysr@1580 | 2834 | Mutex::_no_safepoint_check_flag); |
ysr@1580 | 2835 | ssize_t births = _indexedFreeList[word_sz].splitBirths() + num; |
ysr@1580 | 2836 | _indexedFreeList[word_sz].set_splitBirths(births); |
ysr@1580 | 2837 | return; |
duke@435 | 2838 | } |
duke@435 | 2839 | } |
duke@435 | 2840 | } |
duke@435 | 2841 | // Otherwise, we'll split a block from the dictionary. |
duke@435 | 2842 | FreeChunk* fc = NULL; |
duke@435 | 2843 | FreeChunk* rem_fc = NULL; |
duke@435 | 2844 | size_t rem; |
duke@435 | 2845 | { |
duke@435 | 2846 | MutexLockerEx x(parDictionaryAllocLock(), |
duke@435 | 2847 | Mutex::_no_safepoint_check_flag); |
duke@435 | 2848 | while (n > 0) { |
duke@435 | 2849 | fc = dictionary()->getChunk(MAX2(n * word_sz, |
duke@435 | 2850 | _dictionary->minSize()), |
duke@435 | 2851 | FreeBlockDictionary::atLeast); |
duke@435 | 2852 | if (fc != NULL) { |
ysr@2071 | 2853 | _bt.allocated((HeapWord*)fc, fc->size(), true /* reducing */); // update _unallocated_blk |
duke@435 | 2854 | dictionary()->dictCensusUpdate(fc->size(), |
duke@435 | 2855 | true /*split*/, |
duke@435 | 2856 | false /*birth*/); |
duke@435 | 2857 | break; |
duke@435 | 2858 | } else { |
duke@435 | 2859 | n--; |
duke@435 | 2860 | } |
duke@435 | 2861 | } |
duke@435 | 2862 | if (fc == NULL) return; |
ysr@2071 | 2863 | // Otherwise, split up that block. |
ysr@1580 | 2864 | assert((ssize_t)n >= 1, "Control point invariant"); |
ysr@2071 | 2865 | assert(fc->isFree(), "Error: should be a free block"); |
ysr@2071 | 2866 | _bt.verify_single_block((HeapWord*)fc, fc->size()); |
ysr@1580 | 2867 | const size_t nn = fc->size() / word_sz; |
duke@435 | 2868 | n = MIN2(nn, n); |
ysr@1580 | 2869 | assert((ssize_t)n >= 1, "Control point invariant"); |
duke@435 | 2870 | rem = fc->size() - n * word_sz; |
duke@435 | 2871 | // If there is a remainder, and it's too small, allocate one fewer. |
duke@435 | 2872 | if (rem > 0 && rem < MinChunkSize) { |
duke@435 | 2873 | n--; rem += word_sz; |
duke@435 | 2874 | } |
jmasa@1583 | 2875 | // Note that at this point we may have n == 0. |
jmasa@1583 | 2876 | assert((ssize_t)n >= 0, "Control point invariant"); |
jmasa@1583 | 2877 | |
jmasa@1583 | 2878 | // If n is 0, the chunk fc that was found is not large |
jmasa@1583 | 2879 | // enough to leave a viable remainder. We are unable to |
jmasa@1583 | 2880 | // allocate even one block. Return fc to the |
jmasa@1583 | 2881 | // dictionary and return, leaving "fl" empty. |
jmasa@1583 | 2882 | if (n == 0) { |
jmasa@1583 | 2883 | returnChunkToDictionary(fc); |
ysr@2071 | 2884 | assert(fl->count() == 0, "We never allocated any blocks"); |
jmasa@1583 | 2885 | return; |
jmasa@1583 | 2886 | } |
jmasa@1583 | 2887 | |
duke@435 | 2888 | // First return the remainder, if any. |
duke@435 | 2889 | // Note that we hold the lock until we decide if we're going to give |
ysr@1580 | 2890 | // back the remainder to the dictionary, since a concurrent allocation |
duke@435 | 2891 | // may otherwise see the heap as empty. (We're willing to take that |
duke@435 | 2892 | // hit if the block is a small block.) |
duke@435 | 2893 | if (rem > 0) { |
duke@435 | 2894 | size_t prefix_size = n * word_sz; |
duke@435 | 2895 | rem_fc = (FreeChunk*)((HeapWord*)fc + prefix_size); |
duke@435 | 2896 | rem_fc->setSize(rem); |
ysr@2071 | 2897 | rem_fc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. |
duke@435 | 2898 | rem_fc->linkNext(NULL); |
duke@435 | 2899 | // Above must occur before BOT is updated below. |
ysr@1580 | 2900 | assert((ssize_t)n > 0 && prefix_size > 0 && rem_fc > fc, "Error"); |
ysr@2071 | 2901 | OrderAccess::storestore(); |
duke@435 | 2902 | _bt.split_block((HeapWord*)fc, fc->size(), prefix_size); |
ysr@2071 | 2903 | assert(fc->isFree(), "Error"); |
ysr@2071 | 2904 | fc->setSize(prefix_size); |
duke@435 | 2905 | if (rem >= IndexSetSize) { |
duke@435 | 2906 | returnChunkToDictionary(rem_fc); |
ysr@1580 | 2907 | dictionary()->dictCensusUpdate(rem, true /*split*/, true /*birth*/); |
duke@435 | 2908 | rem_fc = NULL; |
duke@435 | 2909 | } |
duke@435 | 2910 | // Otherwise, return it to the small list below. |
duke@435 | 2911 | } |
duke@435 | 2912 | } |
duke@435 | 2913 | if (rem_fc != NULL) { |
duke@435 | 2914 | MutexLockerEx x(_indexedFreeListParLocks[rem], |
duke@435 | 2915 | Mutex::_no_safepoint_check_flag); |
duke@435 | 2916 | _bt.verify_not_unallocated((HeapWord*)rem_fc, rem_fc->size()); |
duke@435 | 2917 | _indexedFreeList[rem].returnChunkAtHead(rem_fc); |
duke@435 | 2918 | smallSplitBirth(rem); |
duke@435 | 2919 | } |
ysr@1580 | 2920 | assert((ssize_t)n > 0 && fc != NULL, "Consistency"); |
duke@435 | 2921 | // Now do the splitting up. |
duke@435 | 2922 | // Must do this in reverse order, so that anybody attempting to |
duke@435 | 2923 | // access the main chunk sees it as a single free block until we |
duke@435 | 2924 | // change it. |
duke@435 | 2925 | size_t fc_size = n * word_sz; |
duke@435 | 2926 | // All but first chunk in this loop |
duke@435 | 2927 | for (ssize_t i = n-1; i > 0; i--) { |
duke@435 | 2928 | FreeChunk* ffc = (FreeChunk*)((HeapWord*)fc + i * word_sz); |
duke@435 | 2929 | ffc->setSize(word_sz); |
ysr@2071 | 2930 | ffc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. |
duke@435 | 2931 | ffc->linkNext(NULL); |
duke@435 | 2932 | // Above must occur before BOT is updated below. |
ysr@2071 | 2933 | OrderAccess::storestore(); |
duke@435 | 2934 | // splitting from the right, fc_size == (n - i + 1) * wordsize |
ysr@2071 | 2935 | _bt.mark_block((HeapWord*)ffc, word_sz, true /* reducing */); |
duke@435 | 2936 | fc_size -= word_sz; |
duke@435 | 2937 | _bt.verify_not_unallocated((HeapWord*)ffc, ffc->size()); |
duke@435 | 2938 | _bt.verify_single_block((HeapWord*)ffc, ffc->size()); |
duke@435 | 2939 | _bt.verify_single_block((HeapWord*)fc, fc_size); |
duke@435 | 2940 | // Push this on "fl". |
duke@435 | 2941 | fl->returnChunkAtHead(ffc); |
duke@435 | 2942 | } |
duke@435 | 2943 | // First chunk |
ysr@2071 | 2944 | assert(fc->isFree() && fc->size() == n*word_sz, "Error: should still be a free block"); |
ysr@2071 | 2945 | // The blocks above should show their new sizes before the first block below |
duke@435 | 2946 | fc->setSize(word_sz); |
ysr@2071 | 2947 | fc->linkPrev(NULL); // idempotent wrt free-ness, see assert above |
duke@435 | 2948 | fc->linkNext(NULL); |
duke@435 | 2949 | _bt.verify_not_unallocated((HeapWord*)fc, fc->size()); |
duke@435 | 2950 | _bt.verify_single_block((HeapWord*)fc, fc->size()); |
duke@435 | 2951 | fl->returnChunkAtHead(fc); |
duke@435 | 2952 | |
ysr@1580 | 2953 | assert((ssize_t)n > 0 && (ssize_t)n == fl->count(), "Incorrect number of blocks"); |
duke@435 | 2954 | { |
ysr@1580 | 2955 | // Update the stats for this block size. |
duke@435 | 2956 | MutexLockerEx x(_indexedFreeListParLocks[word_sz], |
duke@435 | 2957 | Mutex::_no_safepoint_check_flag); |
ysr@1580 | 2958 | const ssize_t births = _indexedFreeList[word_sz].splitBirths() + n; |
ysr@1580 | 2959 | _indexedFreeList[word_sz].set_splitBirths(births); |
ysr@1580 | 2960 | // ssize_t new_surplus = _indexedFreeList[word_sz].surplus() + n; |
ysr@1580 | 2961 | // _indexedFreeList[word_sz].set_surplus(new_surplus); |
duke@435 | 2962 | } |
duke@435 | 2963 | |
duke@435 | 2964 | // TRAP |
duke@435 | 2965 | assert(fl->tail()->next() == NULL, "List invariant."); |
duke@435 | 2966 | } |
duke@435 | 2967 | |
duke@435 | 2968 | // Set up the space's par_seq_tasks structure for work claiming |
duke@435 | 2969 | // for parallel rescan. See CMSParRemarkTask where this is currently used. |
duke@435 | 2970 | // XXX Need to suitably abstract and generalize this and the next |
duke@435 | 2971 | // method into one. |
duke@435 | 2972 | void |
duke@435 | 2973 | CompactibleFreeListSpace:: |
duke@435 | 2974 | initialize_sequential_subtasks_for_rescan(int n_threads) { |
duke@435 | 2975 | // The "size" of each task is fixed according to rescan_task_size. |
duke@435 | 2976 | assert(n_threads > 0, "Unexpected n_threads argument"); |
duke@435 | 2977 | const size_t task_size = rescan_task_size(); |
duke@435 | 2978 | size_t n_tasks = (used_region().word_size() + task_size - 1)/task_size; |
ysr@775 | 2979 | assert((n_tasks == 0) == used_region().is_empty(), "n_tasks incorrect"); |
ysr@775 | 2980 | assert(n_tasks == 0 || |
ysr@775 | 2981 | ((used_region().start() + (n_tasks - 1)*task_size < used_region().end()) && |
ysr@775 | 2982 | (used_region().start() + n_tasks*task_size >= used_region().end())), |
ysr@775 | 2983 | "n_tasks calculation incorrect"); |
duke@435 | 2984 | SequentialSubTasksDone* pst = conc_par_seq_tasks(); |
duke@435 | 2985 | assert(!pst->valid(), "Clobbering existing data?"); |
jmasa@2188 | 2986 | // Sets the condition for completion of the subtask (how many threads |
jmasa@2188 | 2987 | // need to finish in order to be done). |
jmasa@2188 | 2988 | pst->set_n_threads(n_threads); |
duke@435 | 2989 | pst->set_n_tasks((int)n_tasks); |
duke@435 | 2990 | } |
duke@435 | 2991 | |
duke@435 | 2992 | // Set up the space's par_seq_tasks structure for work claiming |
duke@435 | 2993 | // for parallel concurrent marking. See CMSConcMarkTask where this is currently used. |
duke@435 | 2994 | void |
duke@435 | 2995 | CompactibleFreeListSpace:: |
duke@435 | 2996 | initialize_sequential_subtasks_for_marking(int n_threads, |
duke@435 | 2997 | HeapWord* low) { |
duke@435 | 2998 | // The "size" of each task is fixed according to rescan_task_size. |
duke@435 | 2999 | assert(n_threads > 0, "Unexpected n_threads argument"); |
duke@435 | 3000 | const size_t task_size = marking_task_size(); |
duke@435 | 3001 | assert(task_size > CardTableModRefBS::card_size_in_words && |
duke@435 | 3002 | (task_size % CardTableModRefBS::card_size_in_words == 0), |
duke@435 | 3003 | "Otherwise arithmetic below would be incorrect"); |
duke@435 | 3004 | MemRegion span = _gen->reserved(); |
duke@435 | 3005 | if (low != NULL) { |
duke@435 | 3006 | if (span.contains(low)) { |
duke@435 | 3007 | // Align low down to a card boundary so that |
duke@435 | 3008 | // we can use block_offset_careful() on span boundaries. |
duke@435 | 3009 | HeapWord* aligned_low = (HeapWord*)align_size_down((uintptr_t)low, |
duke@435 | 3010 | CardTableModRefBS::card_size); |
duke@435 | 3011 | // Clip span prefix at aligned_low |
duke@435 | 3012 | span = span.intersection(MemRegion(aligned_low, span.end())); |
duke@435 | 3013 | } else if (low > span.end()) { |
duke@435 | 3014 | span = MemRegion(low, low); // Null region |
duke@435 | 3015 | } // else use entire span |
duke@435 | 3016 | } |
duke@435 | 3017 | assert(span.is_empty() || |
duke@435 | 3018 | ((uintptr_t)span.start() % CardTableModRefBS::card_size == 0), |
duke@435 | 3019 | "span should start at a card boundary"); |
duke@435 | 3020 | size_t n_tasks = (span.word_size() + task_size - 1)/task_size; |
duke@435 | 3021 | assert((n_tasks == 0) == span.is_empty(), "Inconsistency"); |
duke@435 | 3022 | assert(n_tasks == 0 || |
duke@435 | 3023 | ((span.start() + (n_tasks - 1)*task_size < span.end()) && |
duke@435 | 3024 | (span.start() + n_tasks*task_size >= span.end())), |
ysr@775 | 3025 | "n_tasks calculation incorrect"); |
duke@435 | 3026 | SequentialSubTasksDone* pst = conc_par_seq_tasks(); |
duke@435 | 3027 | assert(!pst->valid(), "Clobbering existing data?"); |
jmasa@2188 | 3028 | // Sets the condition for completion of the subtask (how many threads |
jmasa@2188 | 3029 | // need to finish in order to be done). |
jmasa@2188 | 3030 | pst->set_n_threads(n_threads); |
duke@435 | 3031 | pst->set_n_tasks((int)n_tasks); |
duke@435 | 3032 | } |