Wed, 23 Sep 2009 23:56:15 -0700
Merge
duke@435 | 1 | /* |
xdono@1014 | 2 | * Copyright 2001-2009 Sun Microsystems, Inc. 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 | * |
duke@435 | 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
duke@435 | 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
duke@435 | 21 | * have any questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
duke@435 | 25 | # include "incls/_precompiled.incl" |
duke@435 | 26 | # include "incls/_compactibleFreeListSpace.cpp.incl" |
duke@435 | 27 | |
duke@435 | 28 | ///////////////////////////////////////////////////////////////////////// |
duke@435 | 29 | //// CompactibleFreeListSpace |
duke@435 | 30 | ///////////////////////////////////////////////////////////////////////// |
duke@435 | 31 | |
duke@435 | 32 | // highest ranked free list lock rank |
duke@435 | 33 | int CompactibleFreeListSpace::_lockRank = Mutex::leaf + 3; |
duke@435 | 34 | |
duke@435 | 35 | // Constructor |
duke@435 | 36 | CompactibleFreeListSpace::CompactibleFreeListSpace(BlockOffsetSharedArray* bs, |
duke@435 | 37 | MemRegion mr, bool use_adaptive_freelists, |
duke@435 | 38 | FreeBlockDictionary::DictionaryChoice dictionaryChoice) : |
duke@435 | 39 | _dictionaryChoice(dictionaryChoice), |
duke@435 | 40 | _adaptive_freelists(use_adaptive_freelists), |
duke@435 | 41 | _bt(bs, mr), |
duke@435 | 42 | // free list locks are in the range of values taken by _lockRank |
duke@435 | 43 | // This range currently is [_leaf+2, _leaf+3] |
duke@435 | 44 | // Note: this requires that CFLspace c'tors |
duke@435 | 45 | // are called serially in the order in which the locks are |
duke@435 | 46 | // are acquired in the program text. This is true today. |
duke@435 | 47 | _freelistLock(_lockRank--, "CompactibleFreeListSpace._lock", true), |
duke@435 | 48 | _parDictionaryAllocLock(Mutex::leaf - 1, // == rank(ExpandHeap_lock) - 1 |
duke@435 | 49 | "CompactibleFreeListSpace._dict_par_lock", true), |
duke@435 | 50 | _rescan_task_size(CardTableModRefBS::card_size_in_words * BitsPerWord * |
duke@435 | 51 | CMSRescanMultiple), |
duke@435 | 52 | _marking_task_size(CardTableModRefBS::card_size_in_words * BitsPerWord * |
duke@435 | 53 | CMSConcMarkMultiple), |
duke@435 | 54 | _collector(NULL) |
duke@435 | 55 | { |
duke@435 | 56 | _bt.set_space(this); |
jmasa@698 | 57 | initialize(mr, SpaceDecorator::Clear, SpaceDecorator::Mangle); |
duke@435 | 58 | // We have all of "mr", all of which we place in the dictionary |
duke@435 | 59 | // as one big chunk. We'll need to decide here which of several |
duke@435 | 60 | // possible alternative dictionary implementations to use. For |
duke@435 | 61 | // now the choice is easy, since we have only one working |
duke@435 | 62 | // implementation, namely, the simple binary tree (splaying |
duke@435 | 63 | // temporarily disabled). |
duke@435 | 64 | switch (dictionaryChoice) { |
duke@435 | 65 | case FreeBlockDictionary::dictionaryBinaryTree: |
duke@435 | 66 | _dictionary = new BinaryTreeDictionary(mr); |
duke@435 | 67 | break; |
duke@435 | 68 | case FreeBlockDictionary::dictionarySplayTree: |
duke@435 | 69 | case FreeBlockDictionary::dictionarySkipList: |
duke@435 | 70 | default: |
duke@435 | 71 | warning("dictionaryChoice: selected option not understood; using" |
duke@435 | 72 | " default BinaryTreeDictionary implementation instead."); |
duke@435 | 73 | _dictionary = new BinaryTreeDictionary(mr); |
duke@435 | 74 | break; |
duke@435 | 75 | } |
duke@435 | 76 | splitBirth(mr.word_size()); |
duke@435 | 77 | assert(_dictionary != NULL, "CMS dictionary initialization"); |
duke@435 | 78 | // The indexed free lists are initially all empty and are lazily |
duke@435 | 79 | // filled in on demand. Initialize the array elements to NULL. |
duke@435 | 80 | initializeIndexedFreeListArray(); |
duke@435 | 81 | |
duke@435 | 82 | // Not using adaptive free lists assumes that allocation is first |
duke@435 | 83 | // from the linAB's. Also a cms perm gen which can be compacted |
duke@435 | 84 | // has to have the klass's klassKlass allocated at a lower |
duke@435 | 85 | // address in the heap than the klass so that the klassKlass is |
duke@435 | 86 | // moved to its new location before the klass is moved. |
duke@435 | 87 | // Set the _refillSize for the linear allocation blocks |
duke@435 | 88 | if (!use_adaptive_freelists) { |
duke@435 | 89 | FreeChunk* fc = _dictionary->getChunk(mr.word_size()); |
duke@435 | 90 | // The small linAB initially has all the space and will allocate |
duke@435 | 91 | // a chunk of any size. |
duke@435 | 92 | HeapWord* addr = (HeapWord*) fc; |
duke@435 | 93 | _smallLinearAllocBlock.set(addr, fc->size() , |
duke@435 | 94 | 1024*SmallForLinearAlloc, fc->size()); |
duke@435 | 95 | // Note that _unallocated_block is not updated here. |
duke@435 | 96 | // Allocations from the linear allocation block should |
duke@435 | 97 | // update it. |
duke@435 | 98 | } else { |
duke@435 | 99 | _smallLinearAllocBlock.set(0, 0, 1024*SmallForLinearAlloc, |
duke@435 | 100 | SmallForLinearAlloc); |
duke@435 | 101 | } |
duke@435 | 102 | // CMSIndexedFreeListReplenish should be at least 1 |
duke@435 | 103 | CMSIndexedFreeListReplenish = MAX2((uintx)1, CMSIndexedFreeListReplenish); |
duke@435 | 104 | _promoInfo.setSpace(this); |
duke@435 | 105 | if (UseCMSBestFit) { |
duke@435 | 106 | _fitStrategy = FreeBlockBestFitFirst; |
duke@435 | 107 | } else { |
duke@435 | 108 | _fitStrategy = FreeBlockStrategyNone; |
duke@435 | 109 | } |
duke@435 | 110 | checkFreeListConsistency(); |
duke@435 | 111 | |
duke@435 | 112 | // Initialize locks for parallel case. |
duke@435 | 113 | if (ParallelGCThreads > 0) { |
duke@435 | 114 | for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 115 | _indexedFreeListParLocks[i] = new Mutex(Mutex::leaf - 1, // == ExpandHeap_lock - 1 |
duke@435 | 116 | "a freelist par lock", |
duke@435 | 117 | true); |
duke@435 | 118 | if (_indexedFreeListParLocks[i] == NULL) |
duke@435 | 119 | vm_exit_during_initialization("Could not allocate a par lock"); |
duke@435 | 120 | DEBUG_ONLY( |
duke@435 | 121 | _indexedFreeList[i].set_protecting_lock(_indexedFreeListParLocks[i]); |
duke@435 | 122 | ) |
duke@435 | 123 | } |
duke@435 | 124 | _dictionary->set_par_lock(&_parDictionaryAllocLock); |
duke@435 | 125 | } |
duke@435 | 126 | } |
duke@435 | 127 | |
duke@435 | 128 | // Like CompactibleSpace forward() but always calls cross_threshold() to |
duke@435 | 129 | // update the block offset table. Removed initialize_threshold call because |
duke@435 | 130 | // CFLS does not use a block offset array for contiguous spaces. |
duke@435 | 131 | HeapWord* CompactibleFreeListSpace::forward(oop q, size_t size, |
duke@435 | 132 | CompactPoint* cp, HeapWord* compact_top) { |
duke@435 | 133 | // q is alive |
duke@435 | 134 | // First check if we should switch compaction space |
duke@435 | 135 | assert(this == cp->space, "'this' should be current compaction space."); |
duke@435 | 136 | size_t compaction_max_size = pointer_delta(end(), compact_top); |
duke@435 | 137 | assert(adjustObjectSize(size) == cp->space->adjust_object_size_v(size), |
duke@435 | 138 | "virtual adjustObjectSize_v() method is not correct"); |
duke@435 | 139 | size_t adjusted_size = adjustObjectSize(size); |
duke@435 | 140 | assert(compaction_max_size >= MinChunkSize || compaction_max_size == 0, |
duke@435 | 141 | "no small fragments allowed"); |
duke@435 | 142 | assert(minimum_free_block_size() == MinChunkSize, |
duke@435 | 143 | "for de-virtualized reference below"); |
duke@435 | 144 | // Can't leave a nonzero size, residual fragment smaller than MinChunkSize |
duke@435 | 145 | if (adjusted_size + MinChunkSize > compaction_max_size && |
duke@435 | 146 | adjusted_size != compaction_max_size) { |
duke@435 | 147 | do { |
duke@435 | 148 | // switch to next compaction space |
duke@435 | 149 | cp->space->set_compaction_top(compact_top); |
duke@435 | 150 | cp->space = cp->space->next_compaction_space(); |
duke@435 | 151 | if (cp->space == NULL) { |
duke@435 | 152 | cp->gen = GenCollectedHeap::heap()->prev_gen(cp->gen); |
duke@435 | 153 | assert(cp->gen != NULL, "compaction must succeed"); |
duke@435 | 154 | cp->space = cp->gen->first_compaction_space(); |
duke@435 | 155 | assert(cp->space != NULL, "generation must have a first compaction space"); |
duke@435 | 156 | } |
duke@435 | 157 | compact_top = cp->space->bottom(); |
duke@435 | 158 | cp->space->set_compaction_top(compact_top); |
duke@435 | 159 | // The correct adjusted_size may not be the same as that for this method |
duke@435 | 160 | // (i.e., cp->space may no longer be "this" so adjust the size again. |
duke@435 | 161 | // Use the virtual method which is not used above to save the virtual |
duke@435 | 162 | // dispatch. |
duke@435 | 163 | adjusted_size = cp->space->adjust_object_size_v(size); |
duke@435 | 164 | compaction_max_size = pointer_delta(cp->space->end(), compact_top); |
duke@435 | 165 | assert(cp->space->minimum_free_block_size() == 0, "just checking"); |
duke@435 | 166 | } while (adjusted_size > compaction_max_size); |
duke@435 | 167 | } |
duke@435 | 168 | |
duke@435 | 169 | // store the forwarding pointer into the mark word |
duke@435 | 170 | if ((HeapWord*)q != compact_top) { |
duke@435 | 171 | q->forward_to(oop(compact_top)); |
duke@435 | 172 | assert(q->is_gc_marked(), "encoding the pointer should preserve the mark"); |
duke@435 | 173 | } else { |
duke@435 | 174 | // if the object isn't moving we can just set the mark to the default |
duke@435 | 175 | // mark and handle it specially later on. |
duke@435 | 176 | q->init_mark(); |
duke@435 | 177 | assert(q->forwardee() == NULL, "should be forwarded to NULL"); |
duke@435 | 178 | } |
duke@435 | 179 | |
coleenp@548 | 180 | VALIDATE_MARK_SWEEP_ONLY(MarkSweep::register_live_oop(q, adjusted_size)); |
duke@435 | 181 | compact_top += adjusted_size; |
duke@435 | 182 | |
duke@435 | 183 | // we need to update the offset table so that the beginnings of objects can be |
duke@435 | 184 | // found during scavenge. Note that we are updating the offset table based on |
duke@435 | 185 | // where the object will be once the compaction phase finishes. |
duke@435 | 186 | |
duke@435 | 187 | // Always call cross_threshold(). A contiguous space can only call it when |
duke@435 | 188 | // the compaction_top exceeds the current threshold but not for an |
duke@435 | 189 | // non-contiguous space. |
duke@435 | 190 | cp->threshold = |
duke@435 | 191 | cp->space->cross_threshold(compact_top - adjusted_size, compact_top); |
duke@435 | 192 | return compact_top; |
duke@435 | 193 | } |
duke@435 | 194 | |
duke@435 | 195 | // A modified copy of OffsetTableContigSpace::cross_threshold() with _offsets -> _bt |
duke@435 | 196 | // and use of single_block instead of alloc_block. The name here is not really |
duke@435 | 197 | // appropriate - maybe a more general name could be invented for both the |
duke@435 | 198 | // contiguous and noncontiguous spaces. |
duke@435 | 199 | |
duke@435 | 200 | HeapWord* CompactibleFreeListSpace::cross_threshold(HeapWord* start, HeapWord* the_end) { |
duke@435 | 201 | _bt.single_block(start, the_end); |
duke@435 | 202 | return end(); |
duke@435 | 203 | } |
duke@435 | 204 | |
duke@435 | 205 | // Initialize them to NULL. |
duke@435 | 206 | void CompactibleFreeListSpace::initializeIndexedFreeListArray() { |
duke@435 | 207 | for (size_t i = 0; i < IndexSetSize; i++) { |
duke@435 | 208 | // Note that on platforms where objects are double word aligned, |
duke@435 | 209 | // the odd array elements are not used. It is convenient, however, |
duke@435 | 210 | // to map directly from the object size to the array element. |
duke@435 | 211 | _indexedFreeList[i].reset(IndexSetSize); |
duke@435 | 212 | _indexedFreeList[i].set_size(i); |
duke@435 | 213 | assert(_indexedFreeList[i].count() == 0, "reset check failed"); |
duke@435 | 214 | assert(_indexedFreeList[i].head() == NULL, "reset check failed"); |
duke@435 | 215 | assert(_indexedFreeList[i].tail() == NULL, "reset check failed"); |
duke@435 | 216 | assert(_indexedFreeList[i].hint() == IndexSetSize, "reset check failed"); |
duke@435 | 217 | } |
duke@435 | 218 | } |
duke@435 | 219 | |
duke@435 | 220 | void CompactibleFreeListSpace::resetIndexedFreeListArray() { |
duke@435 | 221 | for (int i = 1; i < IndexSetSize; i++) { |
duke@435 | 222 | assert(_indexedFreeList[i].size() == (size_t) i, |
duke@435 | 223 | "Indexed free list sizes are incorrect"); |
duke@435 | 224 | _indexedFreeList[i].reset(IndexSetSize); |
duke@435 | 225 | assert(_indexedFreeList[i].count() == 0, "reset check failed"); |
duke@435 | 226 | assert(_indexedFreeList[i].head() == NULL, "reset check failed"); |
duke@435 | 227 | assert(_indexedFreeList[i].tail() == NULL, "reset check failed"); |
duke@435 | 228 | assert(_indexedFreeList[i].hint() == IndexSetSize, "reset check failed"); |
duke@435 | 229 | } |
duke@435 | 230 | } |
duke@435 | 231 | |
duke@435 | 232 | void CompactibleFreeListSpace::reset(MemRegion mr) { |
duke@435 | 233 | resetIndexedFreeListArray(); |
duke@435 | 234 | dictionary()->reset(); |
duke@435 | 235 | if (BlockOffsetArrayUseUnallocatedBlock) { |
duke@435 | 236 | assert(end() == mr.end(), "We are compacting to the bottom of CMS gen"); |
duke@435 | 237 | // Everything's allocated until proven otherwise. |
duke@435 | 238 | _bt.set_unallocated_block(end()); |
duke@435 | 239 | } |
duke@435 | 240 | if (!mr.is_empty()) { |
duke@435 | 241 | assert(mr.word_size() >= MinChunkSize, "Chunk size is too small"); |
duke@435 | 242 | _bt.single_block(mr.start(), mr.word_size()); |
duke@435 | 243 | FreeChunk* fc = (FreeChunk*) mr.start(); |
duke@435 | 244 | fc->setSize(mr.word_size()); |
duke@435 | 245 | if (mr.word_size() >= IndexSetSize ) { |
duke@435 | 246 | returnChunkToDictionary(fc); |
duke@435 | 247 | } else { |
duke@435 | 248 | _bt.verify_not_unallocated((HeapWord*)fc, fc->size()); |
duke@435 | 249 | _indexedFreeList[mr.word_size()].returnChunkAtHead(fc); |
duke@435 | 250 | } |
duke@435 | 251 | } |
duke@435 | 252 | _promoInfo.reset(); |
duke@435 | 253 | _smallLinearAllocBlock._ptr = NULL; |
duke@435 | 254 | _smallLinearAllocBlock._word_size = 0; |
duke@435 | 255 | } |
duke@435 | 256 | |
duke@435 | 257 | void CompactibleFreeListSpace::reset_after_compaction() { |
duke@435 | 258 | // Reset the space to the new reality - one free chunk. |
duke@435 | 259 | MemRegion mr(compaction_top(), end()); |
duke@435 | 260 | reset(mr); |
duke@435 | 261 | // Now refill the linear allocation block(s) if possible. |
duke@435 | 262 | if (_adaptive_freelists) { |
duke@435 | 263 | refillLinearAllocBlocksIfNeeded(); |
duke@435 | 264 | } else { |
duke@435 | 265 | // Place as much of mr in the linAB as we can get, |
duke@435 | 266 | // provided it was big enough to go into the dictionary. |
duke@435 | 267 | FreeChunk* fc = dictionary()->findLargestDict(); |
duke@435 | 268 | if (fc != NULL) { |
duke@435 | 269 | assert(fc->size() == mr.word_size(), |
duke@435 | 270 | "Why was the chunk broken up?"); |
duke@435 | 271 | removeChunkFromDictionary(fc); |
duke@435 | 272 | HeapWord* addr = (HeapWord*) fc; |
duke@435 | 273 | _smallLinearAllocBlock.set(addr, fc->size() , |
duke@435 | 274 | 1024*SmallForLinearAlloc, fc->size()); |
duke@435 | 275 | // Note that _unallocated_block is not updated here. |
duke@435 | 276 | } |
duke@435 | 277 | } |
duke@435 | 278 | } |
duke@435 | 279 | |
duke@435 | 280 | // Walks the entire dictionary, returning a coterminal |
duke@435 | 281 | // chunk, if it exists. Use with caution since it involves |
duke@435 | 282 | // a potentially complete walk of a potentially large tree. |
duke@435 | 283 | FreeChunk* CompactibleFreeListSpace::find_chunk_at_end() { |
duke@435 | 284 | |
duke@435 | 285 | assert_lock_strong(&_freelistLock); |
duke@435 | 286 | |
duke@435 | 287 | return dictionary()->find_chunk_ends_at(end()); |
duke@435 | 288 | } |
duke@435 | 289 | |
duke@435 | 290 | |
duke@435 | 291 | #ifndef PRODUCT |
duke@435 | 292 | void CompactibleFreeListSpace::initializeIndexedFreeListArrayReturnedBytes() { |
duke@435 | 293 | for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 294 | _indexedFreeList[i].allocation_stats()->set_returnedBytes(0); |
duke@435 | 295 | } |
duke@435 | 296 | } |
duke@435 | 297 | |
duke@435 | 298 | size_t CompactibleFreeListSpace::sumIndexedFreeListArrayReturnedBytes() { |
duke@435 | 299 | size_t sum = 0; |
duke@435 | 300 | for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 301 | sum += _indexedFreeList[i].allocation_stats()->returnedBytes(); |
duke@435 | 302 | } |
duke@435 | 303 | return sum; |
duke@435 | 304 | } |
duke@435 | 305 | |
duke@435 | 306 | size_t CompactibleFreeListSpace::totalCountInIndexedFreeLists() const { |
duke@435 | 307 | size_t count = 0; |
duke@435 | 308 | for (int i = MinChunkSize; i < IndexSetSize; i++) { |
duke@435 | 309 | debug_only( |
duke@435 | 310 | ssize_t total_list_count = 0; |
duke@435 | 311 | for (FreeChunk* fc = _indexedFreeList[i].head(); fc != NULL; |
duke@435 | 312 | fc = fc->next()) { |
duke@435 | 313 | total_list_count++; |
duke@435 | 314 | } |
duke@435 | 315 | assert(total_list_count == _indexedFreeList[i].count(), |
duke@435 | 316 | "Count in list is incorrect"); |
duke@435 | 317 | ) |
duke@435 | 318 | count += _indexedFreeList[i].count(); |
duke@435 | 319 | } |
duke@435 | 320 | return count; |
duke@435 | 321 | } |
duke@435 | 322 | |
duke@435 | 323 | size_t CompactibleFreeListSpace::totalCount() { |
duke@435 | 324 | size_t num = totalCountInIndexedFreeLists(); |
duke@435 | 325 | num += dictionary()->totalCount(); |
duke@435 | 326 | if (_smallLinearAllocBlock._word_size != 0) { |
duke@435 | 327 | num++; |
duke@435 | 328 | } |
duke@435 | 329 | return num; |
duke@435 | 330 | } |
duke@435 | 331 | #endif |
duke@435 | 332 | |
duke@435 | 333 | bool CompactibleFreeListSpace::is_free_block(const HeapWord* p) const { |
duke@435 | 334 | FreeChunk* fc = (FreeChunk*) p; |
duke@435 | 335 | return fc->isFree(); |
duke@435 | 336 | } |
duke@435 | 337 | |
duke@435 | 338 | size_t CompactibleFreeListSpace::used() const { |
duke@435 | 339 | return capacity() - free(); |
duke@435 | 340 | } |
duke@435 | 341 | |
duke@435 | 342 | size_t CompactibleFreeListSpace::free() const { |
duke@435 | 343 | // "MT-safe, but not MT-precise"(TM), if you will: i.e. |
duke@435 | 344 | // if you do this while the structures are in flux you |
duke@435 | 345 | // may get an approximate answer only; for instance |
duke@435 | 346 | // because there is concurrent allocation either |
duke@435 | 347 | // directly by mutators or for promotion during a GC. |
duke@435 | 348 | // It's "MT-safe", however, in the sense that you are guaranteed |
duke@435 | 349 | // not to crash and burn, for instance, because of walking |
duke@435 | 350 | // pointers that could disappear as you were walking them. |
duke@435 | 351 | // The approximation is because the various components |
duke@435 | 352 | // that are read below are not read atomically (and |
duke@435 | 353 | // further the computation of totalSizeInIndexedFreeLists() |
duke@435 | 354 | // is itself a non-atomic computation. The normal use of |
duke@435 | 355 | // this is during a resize operation at the end of GC |
duke@435 | 356 | // and at that time you are guaranteed to get the |
duke@435 | 357 | // correct actual value. However, for instance, this is |
duke@435 | 358 | // also read completely asynchronously by the "perf-sampler" |
duke@435 | 359 | // that supports jvmstat, and you are apt to see the values |
duke@435 | 360 | // flicker in such cases. |
duke@435 | 361 | assert(_dictionary != NULL, "No _dictionary?"); |
duke@435 | 362 | return (_dictionary->totalChunkSize(DEBUG_ONLY(freelistLock())) + |
duke@435 | 363 | totalSizeInIndexedFreeLists() + |
duke@435 | 364 | _smallLinearAllocBlock._word_size) * HeapWordSize; |
duke@435 | 365 | } |
duke@435 | 366 | |
duke@435 | 367 | size_t CompactibleFreeListSpace::max_alloc_in_words() const { |
duke@435 | 368 | assert(_dictionary != NULL, "No _dictionary?"); |
duke@435 | 369 | assert_locked(); |
duke@435 | 370 | size_t res = _dictionary->maxChunkSize(); |
duke@435 | 371 | res = MAX2(res, MIN2(_smallLinearAllocBlock._word_size, |
duke@435 | 372 | (size_t) SmallForLinearAlloc - 1)); |
duke@435 | 373 | // XXX the following could potentially be pretty slow; |
duke@435 | 374 | // should one, pesimally for the rare cases when res |
duke@435 | 375 | // caclulated above is less than IndexSetSize, |
duke@435 | 376 | // just return res calculated above? My reasoning was that |
duke@435 | 377 | // those cases will be so rare that the extra time spent doesn't |
duke@435 | 378 | // really matter.... |
duke@435 | 379 | // Note: do not change the loop test i >= res + IndexSetStride |
duke@435 | 380 | // to i > res below, because i is unsigned and res may be zero. |
duke@435 | 381 | for (size_t i = IndexSetSize - 1; i >= res + IndexSetStride; |
duke@435 | 382 | i -= IndexSetStride) { |
duke@435 | 383 | if (_indexedFreeList[i].head() != NULL) { |
duke@435 | 384 | assert(_indexedFreeList[i].count() != 0, "Inconsistent FreeList"); |
duke@435 | 385 | return i; |
duke@435 | 386 | } |
duke@435 | 387 | } |
duke@435 | 388 | return res; |
duke@435 | 389 | } |
duke@435 | 390 | |
duke@435 | 391 | void CompactibleFreeListSpace::reportFreeListStatistics() const { |
duke@435 | 392 | assert_lock_strong(&_freelistLock); |
duke@435 | 393 | assert(PrintFLSStatistics != 0, "Reporting error"); |
duke@435 | 394 | _dictionary->reportStatistics(); |
duke@435 | 395 | if (PrintFLSStatistics > 1) { |
duke@435 | 396 | reportIndexedFreeListStatistics(); |
duke@435 | 397 | size_t totalSize = totalSizeInIndexedFreeLists() + |
duke@435 | 398 | _dictionary->totalChunkSize(DEBUG_ONLY(freelistLock())); |
duke@435 | 399 | gclog_or_tty->print(" free=%ld frag=%1.4f\n", totalSize, flsFrag()); |
duke@435 | 400 | } |
duke@435 | 401 | } |
duke@435 | 402 | |
duke@435 | 403 | void CompactibleFreeListSpace::reportIndexedFreeListStatistics() const { |
duke@435 | 404 | assert_lock_strong(&_freelistLock); |
duke@435 | 405 | gclog_or_tty->print("Statistics for IndexedFreeLists:\n" |
duke@435 | 406 | "--------------------------------\n"); |
duke@435 | 407 | size_t totalSize = totalSizeInIndexedFreeLists(); |
duke@435 | 408 | size_t freeBlocks = numFreeBlocksInIndexedFreeLists(); |
duke@435 | 409 | gclog_or_tty->print("Total Free Space: %d\n", totalSize); |
duke@435 | 410 | gclog_or_tty->print("Max Chunk Size: %d\n", maxChunkSizeInIndexedFreeLists()); |
duke@435 | 411 | gclog_or_tty->print("Number of Blocks: %d\n", freeBlocks); |
duke@435 | 412 | if (freeBlocks != 0) { |
duke@435 | 413 | gclog_or_tty->print("Av. Block Size: %d\n", totalSize/freeBlocks); |
duke@435 | 414 | } |
duke@435 | 415 | } |
duke@435 | 416 | |
duke@435 | 417 | size_t CompactibleFreeListSpace::numFreeBlocksInIndexedFreeLists() const { |
duke@435 | 418 | size_t res = 0; |
duke@435 | 419 | for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 420 | debug_only( |
duke@435 | 421 | ssize_t recount = 0; |
duke@435 | 422 | for (FreeChunk* fc = _indexedFreeList[i].head(); fc != NULL; |
duke@435 | 423 | fc = fc->next()) { |
duke@435 | 424 | recount += 1; |
duke@435 | 425 | } |
duke@435 | 426 | assert(recount == _indexedFreeList[i].count(), |
duke@435 | 427 | "Incorrect count in list"); |
duke@435 | 428 | ) |
duke@435 | 429 | res += _indexedFreeList[i].count(); |
duke@435 | 430 | } |
duke@435 | 431 | return res; |
duke@435 | 432 | } |
duke@435 | 433 | |
duke@435 | 434 | size_t CompactibleFreeListSpace::maxChunkSizeInIndexedFreeLists() const { |
duke@435 | 435 | for (size_t i = IndexSetSize - 1; i != 0; i -= IndexSetStride) { |
duke@435 | 436 | if (_indexedFreeList[i].head() != NULL) { |
duke@435 | 437 | assert(_indexedFreeList[i].count() != 0, "Inconsistent FreeList"); |
duke@435 | 438 | return (size_t)i; |
duke@435 | 439 | } |
duke@435 | 440 | } |
duke@435 | 441 | return 0; |
duke@435 | 442 | } |
duke@435 | 443 | |
duke@435 | 444 | void CompactibleFreeListSpace::set_end(HeapWord* value) { |
duke@435 | 445 | HeapWord* prevEnd = end(); |
duke@435 | 446 | assert(prevEnd != value, "unnecessary set_end call"); |
duke@435 | 447 | assert(prevEnd == NULL || value >= unallocated_block(), "New end is below unallocated block"); |
duke@435 | 448 | _end = value; |
duke@435 | 449 | if (prevEnd != NULL) { |
duke@435 | 450 | // Resize the underlying block offset table. |
duke@435 | 451 | _bt.resize(pointer_delta(value, bottom())); |
duke@435 | 452 | if (value <= prevEnd) { |
duke@435 | 453 | assert(value >= unallocated_block(), "New end is below unallocated block"); |
duke@435 | 454 | } else { |
duke@435 | 455 | // Now, take this new chunk and add it to the free blocks. |
duke@435 | 456 | // Note that the BOT has not yet been updated for this block. |
duke@435 | 457 | size_t newFcSize = pointer_delta(value, prevEnd); |
duke@435 | 458 | // XXX This is REALLY UGLY and should be fixed up. XXX |
duke@435 | 459 | if (!_adaptive_freelists && _smallLinearAllocBlock._ptr == NULL) { |
duke@435 | 460 | // Mark the boundary of the new block in BOT |
duke@435 | 461 | _bt.mark_block(prevEnd, value); |
duke@435 | 462 | // put it all in the linAB |
duke@435 | 463 | if (ParallelGCThreads == 0) { |
duke@435 | 464 | _smallLinearAllocBlock._ptr = prevEnd; |
duke@435 | 465 | _smallLinearAllocBlock._word_size = newFcSize; |
duke@435 | 466 | repairLinearAllocBlock(&_smallLinearAllocBlock); |
duke@435 | 467 | } else { // ParallelGCThreads > 0 |
duke@435 | 468 | MutexLockerEx x(parDictionaryAllocLock(), |
duke@435 | 469 | Mutex::_no_safepoint_check_flag); |
duke@435 | 470 | _smallLinearAllocBlock._ptr = prevEnd; |
duke@435 | 471 | _smallLinearAllocBlock._word_size = newFcSize; |
duke@435 | 472 | repairLinearAllocBlock(&_smallLinearAllocBlock); |
duke@435 | 473 | } |
duke@435 | 474 | // Births of chunks put into a LinAB are not recorded. Births |
duke@435 | 475 | // of chunks as they are allocated out of a LinAB are. |
duke@435 | 476 | } else { |
duke@435 | 477 | // Add the block to the free lists, if possible coalescing it |
duke@435 | 478 | // with the last free block, and update the BOT and census data. |
duke@435 | 479 | addChunkToFreeListsAtEndRecordingStats(prevEnd, newFcSize); |
duke@435 | 480 | } |
duke@435 | 481 | } |
duke@435 | 482 | } |
duke@435 | 483 | } |
duke@435 | 484 | |
duke@435 | 485 | class FreeListSpace_DCTOC : public Filtering_DCTOC { |
duke@435 | 486 | CompactibleFreeListSpace* _cfls; |
duke@435 | 487 | CMSCollector* _collector; |
duke@435 | 488 | protected: |
duke@435 | 489 | // Override. |
duke@435 | 490 | #define walk_mem_region_with_cl_DECL(ClosureType) \ |
duke@435 | 491 | virtual void walk_mem_region_with_cl(MemRegion mr, \ |
duke@435 | 492 | HeapWord* bottom, HeapWord* top, \ |
duke@435 | 493 | ClosureType* cl); \ |
duke@435 | 494 | void walk_mem_region_with_cl_par(MemRegion mr, \ |
duke@435 | 495 | HeapWord* bottom, HeapWord* top, \ |
duke@435 | 496 | ClosureType* cl); \ |
duke@435 | 497 | void walk_mem_region_with_cl_nopar(MemRegion mr, \ |
duke@435 | 498 | HeapWord* bottom, HeapWord* top, \ |
duke@435 | 499 | ClosureType* cl) |
duke@435 | 500 | walk_mem_region_with_cl_DECL(OopClosure); |
duke@435 | 501 | walk_mem_region_with_cl_DECL(FilteringClosure); |
duke@435 | 502 | |
duke@435 | 503 | public: |
duke@435 | 504 | FreeListSpace_DCTOC(CompactibleFreeListSpace* sp, |
duke@435 | 505 | CMSCollector* collector, |
duke@435 | 506 | OopClosure* cl, |
duke@435 | 507 | CardTableModRefBS::PrecisionStyle precision, |
duke@435 | 508 | HeapWord* boundary) : |
duke@435 | 509 | Filtering_DCTOC(sp, cl, precision, boundary), |
duke@435 | 510 | _cfls(sp), _collector(collector) {} |
duke@435 | 511 | }; |
duke@435 | 512 | |
duke@435 | 513 | // We de-virtualize the block-related calls below, since we know that our |
duke@435 | 514 | // space is a CompactibleFreeListSpace. |
duke@435 | 515 | #define FreeListSpace_DCTOC__walk_mem_region_with_cl_DEFN(ClosureType) \ |
duke@435 | 516 | void FreeListSpace_DCTOC::walk_mem_region_with_cl(MemRegion mr, \ |
duke@435 | 517 | HeapWord* bottom, \ |
duke@435 | 518 | HeapWord* top, \ |
duke@435 | 519 | ClosureType* cl) { \ |
duke@435 | 520 | if (SharedHeap::heap()->n_par_threads() > 0) { \ |
duke@435 | 521 | walk_mem_region_with_cl_par(mr, bottom, top, cl); \ |
duke@435 | 522 | } else { \ |
duke@435 | 523 | walk_mem_region_with_cl_nopar(mr, bottom, top, cl); \ |
duke@435 | 524 | } \ |
duke@435 | 525 | } \ |
duke@435 | 526 | void FreeListSpace_DCTOC::walk_mem_region_with_cl_par(MemRegion mr, \ |
duke@435 | 527 | HeapWord* bottom, \ |
duke@435 | 528 | HeapWord* top, \ |
duke@435 | 529 | ClosureType* cl) { \ |
duke@435 | 530 | /* Skip parts that are before "mr", in case "block_start" sent us \ |
duke@435 | 531 | back too far. */ \ |
duke@435 | 532 | HeapWord* mr_start = mr.start(); \ |
duke@435 | 533 | size_t bot_size = _cfls->CompactibleFreeListSpace::block_size(bottom); \ |
duke@435 | 534 | HeapWord* next = bottom + bot_size; \ |
duke@435 | 535 | while (next < mr_start) { \ |
duke@435 | 536 | bottom = next; \ |
duke@435 | 537 | bot_size = _cfls->CompactibleFreeListSpace::block_size(bottom); \ |
duke@435 | 538 | next = bottom + bot_size; \ |
duke@435 | 539 | } \ |
duke@435 | 540 | \ |
duke@435 | 541 | while (bottom < top) { \ |
duke@435 | 542 | if (_cfls->CompactibleFreeListSpace::block_is_obj(bottom) && \ |
duke@435 | 543 | !_cfls->CompactibleFreeListSpace::obj_allocated_since_save_marks( \ |
duke@435 | 544 | oop(bottom)) && \ |
duke@435 | 545 | !_collector->CMSCollector::is_dead_obj(oop(bottom))) { \ |
duke@435 | 546 | size_t word_sz = oop(bottom)->oop_iterate(cl, mr); \ |
duke@435 | 547 | bottom += _cfls->adjustObjectSize(word_sz); \ |
duke@435 | 548 | } else { \ |
duke@435 | 549 | bottom += _cfls->CompactibleFreeListSpace::block_size(bottom); \ |
duke@435 | 550 | } \ |
duke@435 | 551 | } \ |
duke@435 | 552 | } \ |
duke@435 | 553 | void FreeListSpace_DCTOC::walk_mem_region_with_cl_nopar(MemRegion mr, \ |
duke@435 | 554 | HeapWord* bottom, \ |
duke@435 | 555 | HeapWord* top, \ |
duke@435 | 556 | ClosureType* cl) { \ |
duke@435 | 557 | /* Skip parts that are before "mr", in case "block_start" sent us \ |
duke@435 | 558 | back too far. */ \ |
duke@435 | 559 | HeapWord* mr_start = mr.start(); \ |
duke@435 | 560 | size_t bot_size = _cfls->CompactibleFreeListSpace::block_size_nopar(bottom); \ |
duke@435 | 561 | HeapWord* next = bottom + bot_size; \ |
duke@435 | 562 | while (next < mr_start) { \ |
duke@435 | 563 | bottom = next; \ |
duke@435 | 564 | bot_size = _cfls->CompactibleFreeListSpace::block_size_nopar(bottom); \ |
duke@435 | 565 | next = bottom + bot_size; \ |
duke@435 | 566 | } \ |
duke@435 | 567 | \ |
duke@435 | 568 | while (bottom < top) { \ |
duke@435 | 569 | if (_cfls->CompactibleFreeListSpace::block_is_obj_nopar(bottom) && \ |
duke@435 | 570 | !_cfls->CompactibleFreeListSpace::obj_allocated_since_save_marks( \ |
duke@435 | 571 | oop(bottom)) && \ |
duke@435 | 572 | !_collector->CMSCollector::is_dead_obj(oop(bottom))) { \ |
duke@435 | 573 | size_t word_sz = oop(bottom)->oop_iterate(cl, mr); \ |
duke@435 | 574 | bottom += _cfls->adjustObjectSize(word_sz); \ |
duke@435 | 575 | } else { \ |
duke@435 | 576 | bottom += _cfls->CompactibleFreeListSpace::block_size_nopar(bottom); \ |
duke@435 | 577 | } \ |
duke@435 | 578 | } \ |
duke@435 | 579 | } |
duke@435 | 580 | |
duke@435 | 581 | // (There are only two of these, rather than N, because the split is due |
duke@435 | 582 | // only to the introduction of the FilteringClosure, a local part of the |
duke@435 | 583 | // impl of this abstraction.) |
duke@435 | 584 | FreeListSpace_DCTOC__walk_mem_region_with_cl_DEFN(OopClosure) |
duke@435 | 585 | FreeListSpace_DCTOC__walk_mem_region_with_cl_DEFN(FilteringClosure) |
duke@435 | 586 | |
duke@435 | 587 | DirtyCardToOopClosure* |
duke@435 | 588 | CompactibleFreeListSpace::new_dcto_cl(OopClosure* cl, |
duke@435 | 589 | CardTableModRefBS::PrecisionStyle precision, |
duke@435 | 590 | HeapWord* boundary) { |
duke@435 | 591 | return new FreeListSpace_DCTOC(this, _collector, cl, precision, boundary); |
duke@435 | 592 | } |
duke@435 | 593 | |
duke@435 | 594 | |
duke@435 | 595 | // Note on locking for the space iteration functions: |
duke@435 | 596 | // since the collector's iteration activities are concurrent with |
duke@435 | 597 | // allocation activities by mutators, absent a suitable mutual exclusion |
duke@435 | 598 | // mechanism the iterators may go awry. For instace a block being iterated |
duke@435 | 599 | // may suddenly be allocated or divided up and part of it allocated and |
duke@435 | 600 | // so on. |
duke@435 | 601 | |
duke@435 | 602 | // Apply the given closure to each block in the space. |
duke@435 | 603 | void CompactibleFreeListSpace::blk_iterate_careful(BlkClosureCareful* cl) { |
duke@435 | 604 | assert_lock_strong(freelistLock()); |
duke@435 | 605 | HeapWord *cur, *limit; |
duke@435 | 606 | for (cur = bottom(), limit = end(); cur < limit; |
duke@435 | 607 | cur += cl->do_blk_careful(cur)); |
duke@435 | 608 | } |
duke@435 | 609 | |
duke@435 | 610 | // Apply the given closure to each block in the space. |
duke@435 | 611 | void CompactibleFreeListSpace::blk_iterate(BlkClosure* cl) { |
duke@435 | 612 | assert_lock_strong(freelistLock()); |
duke@435 | 613 | HeapWord *cur, *limit; |
duke@435 | 614 | for (cur = bottom(), limit = end(); cur < limit; |
duke@435 | 615 | cur += cl->do_blk(cur)); |
duke@435 | 616 | } |
duke@435 | 617 | |
duke@435 | 618 | // Apply the given closure to each oop in the space. |
duke@435 | 619 | void CompactibleFreeListSpace::oop_iterate(OopClosure* cl) { |
duke@435 | 620 | assert_lock_strong(freelistLock()); |
duke@435 | 621 | HeapWord *cur, *limit; |
duke@435 | 622 | size_t curSize; |
duke@435 | 623 | for (cur = bottom(), limit = end(); cur < limit; |
duke@435 | 624 | cur += curSize) { |
duke@435 | 625 | curSize = block_size(cur); |
duke@435 | 626 | if (block_is_obj(cur)) { |
duke@435 | 627 | oop(cur)->oop_iterate(cl); |
duke@435 | 628 | } |
duke@435 | 629 | } |
duke@435 | 630 | } |
duke@435 | 631 | |
duke@435 | 632 | // Apply the given closure to each oop in the space \intersect memory region. |
duke@435 | 633 | void CompactibleFreeListSpace::oop_iterate(MemRegion mr, OopClosure* cl) { |
duke@435 | 634 | assert_lock_strong(freelistLock()); |
duke@435 | 635 | if (is_empty()) { |
duke@435 | 636 | return; |
duke@435 | 637 | } |
duke@435 | 638 | MemRegion cur = MemRegion(bottom(), end()); |
duke@435 | 639 | mr = mr.intersection(cur); |
duke@435 | 640 | if (mr.is_empty()) { |
duke@435 | 641 | return; |
duke@435 | 642 | } |
duke@435 | 643 | if (mr.equals(cur)) { |
duke@435 | 644 | oop_iterate(cl); |
duke@435 | 645 | return; |
duke@435 | 646 | } |
duke@435 | 647 | assert(mr.end() <= end(), "just took an intersection above"); |
duke@435 | 648 | HeapWord* obj_addr = block_start(mr.start()); |
duke@435 | 649 | HeapWord* t = mr.end(); |
duke@435 | 650 | |
duke@435 | 651 | SpaceMemRegionOopsIterClosure smr_blk(cl, mr); |
duke@435 | 652 | if (block_is_obj(obj_addr)) { |
duke@435 | 653 | // Handle first object specially. |
duke@435 | 654 | oop obj = oop(obj_addr); |
duke@435 | 655 | obj_addr += adjustObjectSize(obj->oop_iterate(&smr_blk)); |
duke@435 | 656 | } else { |
duke@435 | 657 | FreeChunk* fc = (FreeChunk*)obj_addr; |
duke@435 | 658 | obj_addr += fc->size(); |
duke@435 | 659 | } |
duke@435 | 660 | while (obj_addr < t) { |
duke@435 | 661 | HeapWord* obj = obj_addr; |
duke@435 | 662 | obj_addr += block_size(obj_addr); |
duke@435 | 663 | // If "obj_addr" is not greater than top, then the |
duke@435 | 664 | // entire object "obj" is within the region. |
duke@435 | 665 | if (obj_addr <= t) { |
duke@435 | 666 | if (block_is_obj(obj)) { |
duke@435 | 667 | oop(obj)->oop_iterate(cl); |
duke@435 | 668 | } |
duke@435 | 669 | } else { |
duke@435 | 670 | // "obj" extends beyond end of region |
duke@435 | 671 | if (block_is_obj(obj)) { |
duke@435 | 672 | oop(obj)->oop_iterate(&smr_blk); |
duke@435 | 673 | } |
duke@435 | 674 | break; |
duke@435 | 675 | } |
duke@435 | 676 | } |
duke@435 | 677 | } |
duke@435 | 678 | |
duke@435 | 679 | // NOTE: In the following methods, in order to safely be able to |
duke@435 | 680 | // apply the closure to an object, we need to be sure that the |
duke@435 | 681 | // object has been initialized. We are guaranteed that an object |
duke@435 | 682 | // is initialized if we are holding the Heap_lock with the |
duke@435 | 683 | // world stopped. |
duke@435 | 684 | void CompactibleFreeListSpace::verify_objects_initialized() const { |
duke@435 | 685 | if (is_init_completed()) { |
duke@435 | 686 | assert_locked_or_safepoint(Heap_lock); |
duke@435 | 687 | if (Universe::is_fully_initialized()) { |
duke@435 | 688 | guarantee(SafepointSynchronize::is_at_safepoint(), |
duke@435 | 689 | "Required for objects to be initialized"); |
duke@435 | 690 | } |
duke@435 | 691 | } // else make a concession at vm start-up |
duke@435 | 692 | } |
duke@435 | 693 | |
duke@435 | 694 | // Apply the given closure to each object in the space |
duke@435 | 695 | void CompactibleFreeListSpace::object_iterate(ObjectClosure* blk) { |
duke@435 | 696 | assert_lock_strong(freelistLock()); |
duke@435 | 697 | NOT_PRODUCT(verify_objects_initialized()); |
duke@435 | 698 | HeapWord *cur, *limit; |
duke@435 | 699 | size_t curSize; |
duke@435 | 700 | for (cur = bottom(), limit = end(); cur < limit; |
duke@435 | 701 | cur += curSize) { |
duke@435 | 702 | curSize = block_size(cur); |
duke@435 | 703 | if (block_is_obj(cur)) { |
duke@435 | 704 | blk->do_object(oop(cur)); |
duke@435 | 705 | } |
duke@435 | 706 | } |
duke@435 | 707 | } |
duke@435 | 708 | |
jmasa@952 | 709 | // Apply the given closure to each live object in the space |
jmasa@952 | 710 | // The usage of CompactibleFreeListSpace |
jmasa@952 | 711 | // by the ConcurrentMarkSweepGeneration for concurrent GC's allows |
jmasa@952 | 712 | // objects in the space with references to objects that are no longer |
jmasa@952 | 713 | // valid. For example, an object may reference another object |
jmasa@952 | 714 | // that has already been sweep up (collected). This method uses |
jmasa@952 | 715 | // obj_is_alive() to determine whether it is safe to apply the closure to |
jmasa@952 | 716 | // an object. See obj_is_alive() for details on how liveness of an |
jmasa@952 | 717 | // object is decided. |
jmasa@952 | 718 | |
jmasa@952 | 719 | void CompactibleFreeListSpace::safe_object_iterate(ObjectClosure* blk) { |
jmasa@952 | 720 | assert_lock_strong(freelistLock()); |
jmasa@952 | 721 | NOT_PRODUCT(verify_objects_initialized()); |
jmasa@952 | 722 | HeapWord *cur, *limit; |
jmasa@952 | 723 | size_t curSize; |
jmasa@952 | 724 | for (cur = bottom(), limit = end(); cur < limit; |
jmasa@952 | 725 | cur += curSize) { |
jmasa@952 | 726 | curSize = block_size(cur); |
jmasa@952 | 727 | if (block_is_obj(cur) && obj_is_alive(cur)) { |
jmasa@952 | 728 | blk->do_object(oop(cur)); |
jmasa@952 | 729 | } |
jmasa@952 | 730 | } |
jmasa@952 | 731 | } |
jmasa@952 | 732 | |
duke@435 | 733 | void CompactibleFreeListSpace::object_iterate_mem(MemRegion mr, |
duke@435 | 734 | UpwardsObjectClosure* cl) { |
duke@435 | 735 | assert_locked(); |
duke@435 | 736 | NOT_PRODUCT(verify_objects_initialized()); |
duke@435 | 737 | Space::object_iterate_mem(mr, cl); |
duke@435 | 738 | } |
duke@435 | 739 | |
duke@435 | 740 | // Callers of this iterator beware: The closure application should |
duke@435 | 741 | // be robust in the face of uninitialized objects and should (always) |
duke@435 | 742 | // return a correct size so that the next addr + size below gives us a |
duke@435 | 743 | // valid block boundary. [See for instance, |
duke@435 | 744 | // ScanMarkedObjectsAgainCarefullyClosure::do_object_careful() |
duke@435 | 745 | // in ConcurrentMarkSweepGeneration.cpp.] |
duke@435 | 746 | HeapWord* |
duke@435 | 747 | CompactibleFreeListSpace::object_iterate_careful(ObjectClosureCareful* cl) { |
duke@435 | 748 | assert_lock_strong(freelistLock()); |
duke@435 | 749 | HeapWord *addr, *last; |
duke@435 | 750 | size_t size; |
duke@435 | 751 | for (addr = bottom(), last = end(); |
duke@435 | 752 | addr < last; addr += size) { |
duke@435 | 753 | FreeChunk* fc = (FreeChunk*)addr; |
duke@435 | 754 | if (fc->isFree()) { |
duke@435 | 755 | // Since we hold the free list lock, which protects direct |
duke@435 | 756 | // allocation in this generation by mutators, a free object |
duke@435 | 757 | // will remain free throughout this iteration code. |
duke@435 | 758 | size = fc->size(); |
duke@435 | 759 | } else { |
duke@435 | 760 | // Note that the object need not necessarily be initialized, |
duke@435 | 761 | // because (for instance) the free list lock does NOT protect |
duke@435 | 762 | // object initialization. The closure application below must |
duke@435 | 763 | // therefore be correct in the face of uninitialized objects. |
duke@435 | 764 | size = cl->do_object_careful(oop(addr)); |
duke@435 | 765 | if (size == 0) { |
duke@435 | 766 | // An unparsable object found. Signal early termination. |
duke@435 | 767 | return addr; |
duke@435 | 768 | } |
duke@435 | 769 | } |
duke@435 | 770 | } |
duke@435 | 771 | return NULL; |
duke@435 | 772 | } |
duke@435 | 773 | |
duke@435 | 774 | // Callers of this iterator beware: The closure application should |
duke@435 | 775 | // be robust in the face of uninitialized objects and should (always) |
duke@435 | 776 | // return a correct size so that the next addr + size below gives us a |
duke@435 | 777 | // valid block boundary. [See for instance, |
duke@435 | 778 | // ScanMarkedObjectsAgainCarefullyClosure::do_object_careful() |
duke@435 | 779 | // in ConcurrentMarkSweepGeneration.cpp.] |
duke@435 | 780 | HeapWord* |
duke@435 | 781 | CompactibleFreeListSpace::object_iterate_careful_m(MemRegion mr, |
duke@435 | 782 | ObjectClosureCareful* cl) { |
duke@435 | 783 | assert_lock_strong(freelistLock()); |
duke@435 | 784 | // Can't use used_region() below because it may not necessarily |
duke@435 | 785 | // be the same as [bottom(),end()); although we could |
duke@435 | 786 | // use [used_region().start(),round_to(used_region().end(),CardSize)), |
duke@435 | 787 | // that appears too cumbersome, so we just do the simpler check |
duke@435 | 788 | // in the assertion below. |
duke@435 | 789 | assert(!mr.is_empty() && MemRegion(bottom(),end()).contains(mr), |
duke@435 | 790 | "mr should be non-empty and within used space"); |
duke@435 | 791 | HeapWord *addr, *end; |
duke@435 | 792 | size_t size; |
duke@435 | 793 | for (addr = block_start_careful(mr.start()), end = mr.end(); |
duke@435 | 794 | addr < end; addr += size) { |
duke@435 | 795 | FreeChunk* fc = (FreeChunk*)addr; |
duke@435 | 796 | if (fc->isFree()) { |
duke@435 | 797 | // Since we hold the free list lock, which protects direct |
duke@435 | 798 | // allocation in this generation by mutators, a free object |
duke@435 | 799 | // will remain free throughout this iteration code. |
duke@435 | 800 | size = fc->size(); |
duke@435 | 801 | } else { |
duke@435 | 802 | // Note that the object need not necessarily be initialized, |
duke@435 | 803 | // because (for instance) the free list lock does NOT protect |
duke@435 | 804 | // object initialization. The closure application below must |
duke@435 | 805 | // therefore be correct in the face of uninitialized objects. |
duke@435 | 806 | size = cl->do_object_careful_m(oop(addr), mr); |
duke@435 | 807 | if (size == 0) { |
duke@435 | 808 | // An unparsable object found. Signal early termination. |
duke@435 | 809 | return addr; |
duke@435 | 810 | } |
duke@435 | 811 | } |
duke@435 | 812 | } |
duke@435 | 813 | return NULL; |
duke@435 | 814 | } |
duke@435 | 815 | |
duke@435 | 816 | |
ysr@777 | 817 | HeapWord* CompactibleFreeListSpace::block_start_const(const void* p) const { |
duke@435 | 818 | NOT_PRODUCT(verify_objects_initialized()); |
duke@435 | 819 | return _bt.block_start(p); |
duke@435 | 820 | } |
duke@435 | 821 | |
duke@435 | 822 | HeapWord* CompactibleFreeListSpace::block_start_careful(const void* p) const { |
duke@435 | 823 | return _bt.block_start_careful(p); |
duke@435 | 824 | } |
duke@435 | 825 | |
duke@435 | 826 | size_t CompactibleFreeListSpace::block_size(const HeapWord* p) const { |
duke@435 | 827 | NOT_PRODUCT(verify_objects_initialized()); |
duke@435 | 828 | assert(MemRegion(bottom(), end()).contains(p), "p not in space"); |
duke@435 | 829 | // This must be volatile, or else there is a danger that the compiler |
duke@435 | 830 | // will compile the code below into a sometimes-infinite loop, by keeping |
duke@435 | 831 | // the value read the first time in a register. |
duke@435 | 832 | while (true) { |
duke@435 | 833 | // We must do this until we get a consistent view of the object. |
coleenp@622 | 834 | if (FreeChunk::indicatesFreeChunk(p)) { |
coleenp@622 | 835 | volatile FreeChunk* fc = (volatile FreeChunk*)p; |
coleenp@622 | 836 | size_t res = fc->size(); |
coleenp@622 | 837 | // If the object is still a free chunk, return the size, else it |
coleenp@622 | 838 | // has been allocated so try again. |
coleenp@622 | 839 | if (FreeChunk::indicatesFreeChunk(p)) { |
duke@435 | 840 | assert(res != 0, "Block size should not be 0"); |
duke@435 | 841 | return res; |
duke@435 | 842 | } |
coleenp@622 | 843 | } else { |
coleenp@622 | 844 | // must read from what 'p' points to in each loop. |
coleenp@622 | 845 | klassOop k = ((volatile oopDesc*)p)->klass_or_null(); |
coleenp@622 | 846 | if (k != NULL) { |
coleenp@622 | 847 | assert(k->is_oop(true /* ignore mark word */), "Should really be klass oop."); |
coleenp@622 | 848 | oop o = (oop)p; |
coleenp@622 | 849 | assert(o->is_parsable(), "Should be parsable"); |
coleenp@622 | 850 | assert(o->is_oop(true /* ignore mark word */), "Should be an oop."); |
coleenp@622 | 851 | size_t res = o->size_given_klass(k->klass_part()); |
coleenp@622 | 852 | res = adjustObjectSize(res); |
coleenp@622 | 853 | assert(res != 0, "Block size should not be 0"); |
coleenp@622 | 854 | return res; |
coleenp@622 | 855 | } |
duke@435 | 856 | } |
duke@435 | 857 | } |
duke@435 | 858 | } |
duke@435 | 859 | |
duke@435 | 860 | // A variant of the above that uses the Printezis bits for |
duke@435 | 861 | // unparsable but allocated objects. This avoids any possible |
duke@435 | 862 | // stalls waiting for mutators to initialize objects, and is |
duke@435 | 863 | // thus potentially faster than the variant above. However, |
duke@435 | 864 | // this variant may return a zero size for a block that is |
duke@435 | 865 | // under mutation and for which a consistent size cannot be |
duke@435 | 866 | // inferred without stalling; see CMSCollector::block_size_if_printezis_bits(). |
duke@435 | 867 | size_t CompactibleFreeListSpace::block_size_no_stall(HeapWord* p, |
duke@435 | 868 | const CMSCollector* c) |
duke@435 | 869 | const { |
duke@435 | 870 | assert(MemRegion(bottom(), end()).contains(p), "p not in space"); |
duke@435 | 871 | // This must be volatile, or else there is a danger that the compiler |
duke@435 | 872 | // will compile the code below into a sometimes-infinite loop, by keeping |
duke@435 | 873 | // the value read the first time in a register. |
duke@435 | 874 | DEBUG_ONLY(uint loops = 0;) |
duke@435 | 875 | while (true) { |
duke@435 | 876 | // We must do this until we get a consistent view of the object. |
coleenp@622 | 877 | if (FreeChunk::indicatesFreeChunk(p)) { |
coleenp@622 | 878 | volatile FreeChunk* fc = (volatile FreeChunk*)p; |
coleenp@622 | 879 | size_t res = fc->size(); |
coleenp@622 | 880 | if (FreeChunk::indicatesFreeChunk(p)) { |
duke@435 | 881 | assert(res != 0, "Block size should not be 0"); |
duke@435 | 882 | assert(loops == 0, "Should be 0"); |
duke@435 | 883 | return res; |
duke@435 | 884 | } |
duke@435 | 885 | } else { |
coleenp@622 | 886 | // must read from what 'p' points to in each loop. |
coleenp@622 | 887 | klassOop k = ((volatile oopDesc*)p)->klass_or_null(); |
jmasa@953 | 888 | if (k != NULL && |
jmasa@953 | 889 | ((oopDesc*)p)->is_parsable() && |
jmasa@953 | 890 | ((oopDesc*)p)->is_conc_safe()) { |
coleenp@622 | 891 | assert(k->is_oop(), "Should really be klass oop."); |
coleenp@622 | 892 | oop o = (oop)p; |
coleenp@622 | 893 | assert(o->is_oop(), "Should be an oop"); |
coleenp@622 | 894 | size_t res = o->size_given_klass(k->klass_part()); |
coleenp@622 | 895 | res = adjustObjectSize(res); |
coleenp@622 | 896 | assert(res != 0, "Block size should not be 0"); |
coleenp@622 | 897 | return res; |
coleenp@622 | 898 | } else { |
coleenp@622 | 899 | return c->block_size_if_printezis_bits(p); |
coleenp@622 | 900 | } |
duke@435 | 901 | } |
duke@435 | 902 | assert(loops == 0, "Can loop at most once"); |
duke@435 | 903 | DEBUG_ONLY(loops++;) |
duke@435 | 904 | } |
duke@435 | 905 | } |
duke@435 | 906 | |
duke@435 | 907 | size_t CompactibleFreeListSpace::block_size_nopar(const HeapWord* p) const { |
duke@435 | 908 | NOT_PRODUCT(verify_objects_initialized()); |
duke@435 | 909 | assert(MemRegion(bottom(), end()).contains(p), "p not in space"); |
duke@435 | 910 | FreeChunk* fc = (FreeChunk*)p; |
duke@435 | 911 | if (fc->isFree()) { |
duke@435 | 912 | return fc->size(); |
duke@435 | 913 | } else { |
duke@435 | 914 | // Ignore mark word because this may be a recently promoted |
duke@435 | 915 | // object whose mark word is used to chain together grey |
duke@435 | 916 | // objects (the last one would have a null value). |
duke@435 | 917 | assert(oop(p)->is_oop(true), "Should be an oop"); |
duke@435 | 918 | return adjustObjectSize(oop(p)->size()); |
duke@435 | 919 | } |
duke@435 | 920 | } |
duke@435 | 921 | |
duke@435 | 922 | // This implementation assumes that the property of "being an object" is |
duke@435 | 923 | // stable. But being a free chunk may not be (because of parallel |
duke@435 | 924 | // promotion.) |
duke@435 | 925 | bool CompactibleFreeListSpace::block_is_obj(const HeapWord* p) const { |
duke@435 | 926 | FreeChunk* fc = (FreeChunk*)p; |
duke@435 | 927 | assert(is_in_reserved(p), "Should be in space"); |
duke@435 | 928 | // When doing a mark-sweep-compact of the CMS generation, this |
duke@435 | 929 | // assertion may fail because prepare_for_compaction() uses |
duke@435 | 930 | // space that is garbage to maintain information on ranges of |
duke@435 | 931 | // live objects so that these live ranges can be moved as a whole. |
duke@435 | 932 | // Comment out this assertion until that problem can be solved |
duke@435 | 933 | // (i.e., that the block start calculation may look at objects |
duke@435 | 934 | // at address below "p" in finding the object that contains "p" |
duke@435 | 935 | // and those objects (if garbage) may have been modified to hold |
duke@435 | 936 | // live range information. |
duke@435 | 937 | // assert(ParallelGCThreads > 0 || _bt.block_start(p) == p, "Should be a block boundary"); |
coleenp@622 | 938 | if (FreeChunk::indicatesFreeChunk(p)) return false; |
coleenp@622 | 939 | klassOop k = oop(p)->klass_or_null(); |
duke@435 | 940 | if (k != NULL) { |
duke@435 | 941 | // Ignore mark word because it may have been used to |
duke@435 | 942 | // chain together promoted objects (the last one |
duke@435 | 943 | // would have a null value). |
duke@435 | 944 | assert(oop(p)->is_oop(true), "Should be an oop"); |
duke@435 | 945 | return true; |
duke@435 | 946 | } else { |
duke@435 | 947 | return false; // Was not an object at the start of collection. |
duke@435 | 948 | } |
duke@435 | 949 | } |
duke@435 | 950 | |
duke@435 | 951 | // Check if the object is alive. This fact is checked either by consulting |
duke@435 | 952 | // the main marking bitmap in the sweeping phase or, if it's a permanent |
duke@435 | 953 | // generation and we're not in the sweeping phase, by checking the |
duke@435 | 954 | // perm_gen_verify_bit_map where we store the "deadness" information if |
duke@435 | 955 | // we did not sweep the perm gen in the most recent previous GC cycle. |
duke@435 | 956 | bool CompactibleFreeListSpace::obj_is_alive(const HeapWord* p) const { |
duke@435 | 957 | assert (block_is_obj(p), "The address should point to an object"); |
duke@435 | 958 | |
duke@435 | 959 | // If we're sweeping, we use object liveness information from the main bit map |
duke@435 | 960 | // for both perm gen and old gen. |
duke@435 | 961 | // We don't need to lock the bitmap (live_map or dead_map below), because |
duke@435 | 962 | // EITHER we are in the middle of the sweeping phase, and the |
duke@435 | 963 | // main marking bit map (live_map below) is locked, |
duke@435 | 964 | // OR we're in other phases and perm_gen_verify_bit_map (dead_map below) |
duke@435 | 965 | // is stable, because it's mutated only in the sweeping phase. |
duke@435 | 966 | if (_collector->abstract_state() == CMSCollector::Sweeping) { |
duke@435 | 967 | CMSBitMap* live_map = _collector->markBitMap(); |
duke@435 | 968 | return live_map->isMarked((HeapWord*) p); |
duke@435 | 969 | } else { |
duke@435 | 970 | // If we're not currently sweeping and we haven't swept the perm gen in |
duke@435 | 971 | // the previous concurrent cycle then we may have dead but unswept objects |
duke@435 | 972 | // in the perm gen. In this case, we use the "deadness" information |
duke@435 | 973 | // that we had saved in perm_gen_verify_bit_map at the last sweep. |
duke@435 | 974 | if (!CMSClassUnloadingEnabled && _collector->_permGen->reserved().contains(p)) { |
duke@435 | 975 | if (_collector->verifying()) { |
duke@435 | 976 | CMSBitMap* dead_map = _collector->perm_gen_verify_bit_map(); |
duke@435 | 977 | // Object is marked in the dead_map bitmap at the previous sweep |
duke@435 | 978 | // when we know that it's dead; if the bitmap is not allocated then |
duke@435 | 979 | // the object is alive. |
duke@435 | 980 | return (dead_map->sizeInBits() == 0) // bit_map has been allocated |
duke@435 | 981 | || !dead_map->par_isMarked((HeapWord*) p); |
duke@435 | 982 | } else { |
duke@435 | 983 | return false; // We can't say for sure if it's live, so we say that it's dead. |
duke@435 | 984 | } |
duke@435 | 985 | } |
duke@435 | 986 | } |
duke@435 | 987 | return true; |
duke@435 | 988 | } |
duke@435 | 989 | |
duke@435 | 990 | bool CompactibleFreeListSpace::block_is_obj_nopar(const HeapWord* p) const { |
duke@435 | 991 | FreeChunk* fc = (FreeChunk*)p; |
duke@435 | 992 | assert(is_in_reserved(p), "Should be in space"); |
duke@435 | 993 | assert(_bt.block_start(p) == p, "Should be a block boundary"); |
duke@435 | 994 | if (!fc->isFree()) { |
duke@435 | 995 | // Ignore mark word because it may have been used to |
duke@435 | 996 | // chain together promoted objects (the last one |
duke@435 | 997 | // would have a null value). |
duke@435 | 998 | assert(oop(p)->is_oop(true), "Should be an oop"); |
duke@435 | 999 | return true; |
duke@435 | 1000 | } |
duke@435 | 1001 | return false; |
duke@435 | 1002 | } |
duke@435 | 1003 | |
duke@435 | 1004 | // "MT-safe but not guaranteed MT-precise" (TM); you may get an |
duke@435 | 1005 | // approximate answer if you don't hold the freelistlock when you call this. |
duke@435 | 1006 | size_t CompactibleFreeListSpace::totalSizeInIndexedFreeLists() const { |
duke@435 | 1007 | size_t size = 0; |
duke@435 | 1008 | for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 1009 | debug_only( |
duke@435 | 1010 | // We may be calling here without the lock in which case we |
duke@435 | 1011 | // won't do this modest sanity check. |
duke@435 | 1012 | if (freelistLock()->owned_by_self()) { |
duke@435 | 1013 | size_t total_list_size = 0; |
duke@435 | 1014 | for (FreeChunk* fc = _indexedFreeList[i].head(); fc != NULL; |
duke@435 | 1015 | fc = fc->next()) { |
duke@435 | 1016 | total_list_size += i; |
duke@435 | 1017 | } |
duke@435 | 1018 | assert(total_list_size == i * _indexedFreeList[i].count(), |
duke@435 | 1019 | "Count in list is incorrect"); |
duke@435 | 1020 | } |
duke@435 | 1021 | ) |
duke@435 | 1022 | size += i * _indexedFreeList[i].count(); |
duke@435 | 1023 | } |
duke@435 | 1024 | return size; |
duke@435 | 1025 | } |
duke@435 | 1026 | |
duke@435 | 1027 | HeapWord* CompactibleFreeListSpace::par_allocate(size_t size) { |
duke@435 | 1028 | MutexLockerEx x(freelistLock(), Mutex::_no_safepoint_check_flag); |
duke@435 | 1029 | return allocate(size); |
duke@435 | 1030 | } |
duke@435 | 1031 | |
duke@435 | 1032 | HeapWord* |
duke@435 | 1033 | CompactibleFreeListSpace::getChunkFromSmallLinearAllocBlockRemainder(size_t size) { |
duke@435 | 1034 | return getChunkFromLinearAllocBlockRemainder(&_smallLinearAllocBlock, size); |
duke@435 | 1035 | } |
duke@435 | 1036 | |
duke@435 | 1037 | HeapWord* CompactibleFreeListSpace::allocate(size_t size) { |
duke@435 | 1038 | assert_lock_strong(freelistLock()); |
duke@435 | 1039 | HeapWord* res = NULL; |
duke@435 | 1040 | assert(size == adjustObjectSize(size), |
duke@435 | 1041 | "use adjustObjectSize() before calling into allocate()"); |
duke@435 | 1042 | |
duke@435 | 1043 | if (_adaptive_freelists) { |
duke@435 | 1044 | res = allocate_adaptive_freelists(size); |
duke@435 | 1045 | } else { // non-adaptive free lists |
duke@435 | 1046 | res = allocate_non_adaptive_freelists(size); |
duke@435 | 1047 | } |
duke@435 | 1048 | |
duke@435 | 1049 | if (res != NULL) { |
duke@435 | 1050 | // check that res does lie in this space! |
duke@435 | 1051 | assert(is_in_reserved(res), "Not in this space!"); |
duke@435 | 1052 | assert(is_aligned((void*)res), "alignment check"); |
duke@435 | 1053 | |
duke@435 | 1054 | FreeChunk* fc = (FreeChunk*)res; |
duke@435 | 1055 | fc->markNotFree(); |
duke@435 | 1056 | assert(!fc->isFree(), "shouldn't be marked free"); |
coleenp@622 | 1057 | assert(oop(fc)->klass_or_null() == NULL, "should look uninitialized"); |
duke@435 | 1058 | // Verify that the block offset table shows this to |
duke@435 | 1059 | // be a single block, but not one which is unallocated. |
duke@435 | 1060 | _bt.verify_single_block(res, size); |
duke@435 | 1061 | _bt.verify_not_unallocated(res, size); |
duke@435 | 1062 | // mangle a just allocated object with a distinct pattern. |
duke@435 | 1063 | debug_only(fc->mangleAllocated(size)); |
duke@435 | 1064 | } |
duke@435 | 1065 | |
duke@435 | 1066 | return res; |
duke@435 | 1067 | } |
duke@435 | 1068 | |
duke@435 | 1069 | HeapWord* CompactibleFreeListSpace::allocate_non_adaptive_freelists(size_t size) { |
duke@435 | 1070 | HeapWord* res = NULL; |
duke@435 | 1071 | // try and use linear allocation for smaller blocks |
duke@435 | 1072 | if (size < _smallLinearAllocBlock._allocation_size_limit) { |
duke@435 | 1073 | // if successful, the following also adjusts block offset table |
duke@435 | 1074 | res = getChunkFromSmallLinearAllocBlock(size); |
duke@435 | 1075 | } |
duke@435 | 1076 | // Else triage to indexed lists for smaller sizes |
duke@435 | 1077 | if (res == NULL) { |
duke@435 | 1078 | if (size < SmallForDictionary) { |
duke@435 | 1079 | res = (HeapWord*) getChunkFromIndexedFreeList(size); |
duke@435 | 1080 | } else { |
duke@435 | 1081 | // else get it from the big dictionary; if even this doesn't |
duke@435 | 1082 | // work we are out of luck. |
duke@435 | 1083 | res = (HeapWord*)getChunkFromDictionaryExact(size); |
duke@435 | 1084 | } |
duke@435 | 1085 | } |
duke@435 | 1086 | |
duke@435 | 1087 | return res; |
duke@435 | 1088 | } |
duke@435 | 1089 | |
duke@435 | 1090 | HeapWord* CompactibleFreeListSpace::allocate_adaptive_freelists(size_t size) { |
duke@435 | 1091 | assert_lock_strong(freelistLock()); |
duke@435 | 1092 | HeapWord* res = NULL; |
duke@435 | 1093 | assert(size == adjustObjectSize(size), |
duke@435 | 1094 | "use adjustObjectSize() before calling into allocate()"); |
duke@435 | 1095 | |
duke@435 | 1096 | // Strategy |
duke@435 | 1097 | // if small |
duke@435 | 1098 | // exact size from small object indexed list if small |
duke@435 | 1099 | // small or large linear allocation block (linAB) as appropriate |
duke@435 | 1100 | // take from lists of greater sized chunks |
duke@435 | 1101 | // else |
duke@435 | 1102 | // dictionary |
duke@435 | 1103 | // small or large linear allocation block if it has the space |
duke@435 | 1104 | // Try allocating exact size from indexTable first |
duke@435 | 1105 | if (size < IndexSetSize) { |
duke@435 | 1106 | res = (HeapWord*) getChunkFromIndexedFreeList(size); |
duke@435 | 1107 | if(res != NULL) { |
duke@435 | 1108 | assert(res != (HeapWord*)_indexedFreeList[size].head(), |
duke@435 | 1109 | "Not removed from free list"); |
duke@435 | 1110 | // no block offset table adjustment is necessary on blocks in |
duke@435 | 1111 | // the indexed lists. |
duke@435 | 1112 | |
duke@435 | 1113 | // Try allocating from the small LinAB |
duke@435 | 1114 | } else if (size < _smallLinearAllocBlock._allocation_size_limit && |
duke@435 | 1115 | (res = getChunkFromSmallLinearAllocBlock(size)) != NULL) { |
duke@435 | 1116 | // if successful, the above also adjusts block offset table |
duke@435 | 1117 | // Note that this call will refill the LinAB to |
duke@435 | 1118 | // satisfy the request. This is different that |
duke@435 | 1119 | // evm. |
duke@435 | 1120 | // Don't record chunk off a LinAB? smallSplitBirth(size); |
duke@435 | 1121 | |
duke@435 | 1122 | } else { |
duke@435 | 1123 | // Raid the exact free lists larger than size, even if they are not |
duke@435 | 1124 | // overpopulated. |
duke@435 | 1125 | res = (HeapWord*) getChunkFromGreater(size); |
duke@435 | 1126 | } |
duke@435 | 1127 | } else { |
duke@435 | 1128 | // Big objects get allocated directly from the dictionary. |
duke@435 | 1129 | res = (HeapWord*) getChunkFromDictionaryExact(size); |
duke@435 | 1130 | if (res == NULL) { |
duke@435 | 1131 | // Try hard not to fail since an allocation failure will likely |
duke@435 | 1132 | // trigger a synchronous GC. Try to get the space from the |
duke@435 | 1133 | // allocation blocks. |
duke@435 | 1134 | res = getChunkFromSmallLinearAllocBlockRemainder(size); |
duke@435 | 1135 | } |
duke@435 | 1136 | } |
duke@435 | 1137 | |
duke@435 | 1138 | return res; |
duke@435 | 1139 | } |
duke@435 | 1140 | |
duke@435 | 1141 | // A worst-case estimate of the space required (in HeapWords) to expand the heap |
duke@435 | 1142 | // when promoting obj. |
duke@435 | 1143 | size_t CompactibleFreeListSpace::expansionSpaceRequired(size_t obj_size) const { |
duke@435 | 1144 | // Depending on the object size, expansion may require refilling either a |
duke@435 | 1145 | // bigLAB or a smallLAB plus refilling a PromotionInfo object. MinChunkSize |
duke@435 | 1146 | // is added because the dictionary may over-allocate to avoid fragmentation. |
duke@435 | 1147 | size_t space = obj_size; |
duke@435 | 1148 | if (!_adaptive_freelists) { |
duke@435 | 1149 | space = MAX2(space, _smallLinearAllocBlock._refillSize); |
duke@435 | 1150 | } |
duke@435 | 1151 | space += _promoInfo.refillSize() + 2 * MinChunkSize; |
duke@435 | 1152 | return space; |
duke@435 | 1153 | } |
duke@435 | 1154 | |
duke@435 | 1155 | FreeChunk* CompactibleFreeListSpace::getChunkFromGreater(size_t numWords) { |
duke@435 | 1156 | FreeChunk* ret; |
duke@435 | 1157 | |
duke@435 | 1158 | assert(numWords >= MinChunkSize, "Size is less than minimum"); |
duke@435 | 1159 | assert(linearAllocationWouldFail() || bestFitFirst(), |
duke@435 | 1160 | "Should not be here"); |
duke@435 | 1161 | |
duke@435 | 1162 | size_t i; |
duke@435 | 1163 | size_t currSize = numWords + MinChunkSize; |
duke@435 | 1164 | assert(currSize % MinObjAlignment == 0, "currSize should be aligned"); |
duke@435 | 1165 | for (i = currSize; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 1166 | FreeList* fl = &_indexedFreeList[i]; |
duke@435 | 1167 | if (fl->head()) { |
duke@435 | 1168 | ret = getFromListGreater(fl, numWords); |
duke@435 | 1169 | assert(ret == NULL || ret->isFree(), "Should be returning a free chunk"); |
duke@435 | 1170 | return ret; |
duke@435 | 1171 | } |
duke@435 | 1172 | } |
duke@435 | 1173 | |
duke@435 | 1174 | currSize = MAX2((size_t)SmallForDictionary, |
duke@435 | 1175 | (size_t)(numWords + MinChunkSize)); |
duke@435 | 1176 | |
duke@435 | 1177 | /* Try to get a chunk that satisfies request, while avoiding |
duke@435 | 1178 | fragmentation that can't be handled. */ |
duke@435 | 1179 | { |
duke@435 | 1180 | ret = dictionary()->getChunk(currSize); |
duke@435 | 1181 | if (ret != NULL) { |
duke@435 | 1182 | assert(ret->size() - numWords >= MinChunkSize, |
duke@435 | 1183 | "Chunk is too small"); |
duke@435 | 1184 | _bt.allocated((HeapWord*)ret, ret->size()); |
duke@435 | 1185 | /* Carve returned chunk. */ |
duke@435 | 1186 | (void) splitChunkAndReturnRemainder(ret, numWords); |
duke@435 | 1187 | /* Label this as no longer a free chunk. */ |
duke@435 | 1188 | assert(ret->isFree(), "This chunk should be free"); |
duke@435 | 1189 | ret->linkPrev(NULL); |
duke@435 | 1190 | } |
duke@435 | 1191 | assert(ret == NULL || ret->isFree(), "Should be returning a free chunk"); |
duke@435 | 1192 | return ret; |
duke@435 | 1193 | } |
duke@435 | 1194 | ShouldNotReachHere(); |
duke@435 | 1195 | } |
duke@435 | 1196 | |
duke@435 | 1197 | bool CompactibleFreeListSpace::verifyChunkInIndexedFreeLists(FreeChunk* fc) |
duke@435 | 1198 | const { |
duke@435 | 1199 | assert(fc->size() < IndexSetSize, "Size of chunk is too large"); |
duke@435 | 1200 | return _indexedFreeList[fc->size()].verifyChunkInFreeLists(fc); |
duke@435 | 1201 | } |
duke@435 | 1202 | |
duke@435 | 1203 | bool CompactibleFreeListSpace::verifyChunkInFreeLists(FreeChunk* fc) const { |
duke@435 | 1204 | if (fc->size() >= IndexSetSize) { |
duke@435 | 1205 | return dictionary()->verifyChunkInFreeLists(fc); |
duke@435 | 1206 | } else { |
duke@435 | 1207 | return verifyChunkInIndexedFreeLists(fc); |
duke@435 | 1208 | } |
duke@435 | 1209 | } |
duke@435 | 1210 | |
duke@435 | 1211 | #ifndef PRODUCT |
duke@435 | 1212 | void CompactibleFreeListSpace::assert_locked() const { |
duke@435 | 1213 | CMSLockVerifier::assert_locked(freelistLock(), parDictionaryAllocLock()); |
duke@435 | 1214 | } |
duke@435 | 1215 | #endif |
duke@435 | 1216 | |
duke@435 | 1217 | FreeChunk* CompactibleFreeListSpace::allocateScratch(size_t size) { |
duke@435 | 1218 | // In the parallel case, the main thread holds the free list lock |
duke@435 | 1219 | // on behalf the parallel threads. |
duke@435 | 1220 | assert_locked(); |
duke@435 | 1221 | FreeChunk* fc; |
duke@435 | 1222 | { |
duke@435 | 1223 | // If GC is parallel, this might be called by several threads. |
duke@435 | 1224 | // This should be rare enough that the locking overhead won't affect |
duke@435 | 1225 | // the sequential code. |
duke@435 | 1226 | MutexLockerEx x(parDictionaryAllocLock(), |
duke@435 | 1227 | Mutex::_no_safepoint_check_flag); |
duke@435 | 1228 | fc = getChunkFromDictionary(size); |
duke@435 | 1229 | } |
duke@435 | 1230 | if (fc != NULL) { |
duke@435 | 1231 | fc->dontCoalesce(); |
duke@435 | 1232 | assert(fc->isFree(), "Should be free, but not coalescable"); |
duke@435 | 1233 | // Verify that the block offset table shows this to |
duke@435 | 1234 | // be a single block, but not one which is unallocated. |
duke@435 | 1235 | _bt.verify_single_block((HeapWord*)fc, fc->size()); |
duke@435 | 1236 | _bt.verify_not_unallocated((HeapWord*)fc, fc->size()); |
duke@435 | 1237 | } |
duke@435 | 1238 | return fc; |
duke@435 | 1239 | } |
duke@435 | 1240 | |
coleenp@548 | 1241 | oop CompactibleFreeListSpace::promote(oop obj, size_t obj_size) { |
duke@435 | 1242 | assert(obj_size == (size_t)obj->size(), "bad obj_size passed in"); |
duke@435 | 1243 | assert_locked(); |
duke@435 | 1244 | |
duke@435 | 1245 | // if we are tracking promotions, then first ensure space for |
duke@435 | 1246 | // promotion (including spooling space for saving header if necessary). |
duke@435 | 1247 | // then allocate and copy, then track promoted info if needed. |
duke@435 | 1248 | // When tracking (see PromotionInfo::track()), the mark word may |
duke@435 | 1249 | // be displaced and in this case restoration of the mark word |
duke@435 | 1250 | // occurs in the (oop_since_save_marks_)iterate phase. |
duke@435 | 1251 | if (_promoInfo.tracking() && !_promoInfo.ensure_spooling_space()) { |
duke@435 | 1252 | return NULL; |
duke@435 | 1253 | } |
duke@435 | 1254 | // Call the allocate(size_t, bool) form directly to avoid the |
duke@435 | 1255 | // additional call through the allocate(size_t) form. Having |
duke@435 | 1256 | // the compile inline the call is problematic because allocate(size_t) |
duke@435 | 1257 | // is a virtual method. |
duke@435 | 1258 | HeapWord* res = allocate(adjustObjectSize(obj_size)); |
duke@435 | 1259 | if (res != NULL) { |
duke@435 | 1260 | Copy::aligned_disjoint_words((HeapWord*)obj, res, obj_size); |
duke@435 | 1261 | // if we should be tracking promotions, do so. |
duke@435 | 1262 | if (_promoInfo.tracking()) { |
duke@435 | 1263 | _promoInfo.track((PromotedObject*)res); |
duke@435 | 1264 | } |
duke@435 | 1265 | } |
duke@435 | 1266 | return oop(res); |
duke@435 | 1267 | } |
duke@435 | 1268 | |
duke@435 | 1269 | HeapWord* |
duke@435 | 1270 | CompactibleFreeListSpace::getChunkFromSmallLinearAllocBlock(size_t size) { |
duke@435 | 1271 | assert_locked(); |
duke@435 | 1272 | assert(size >= MinChunkSize, "minimum chunk size"); |
duke@435 | 1273 | assert(size < _smallLinearAllocBlock._allocation_size_limit, |
duke@435 | 1274 | "maximum from smallLinearAllocBlock"); |
duke@435 | 1275 | return getChunkFromLinearAllocBlock(&_smallLinearAllocBlock, size); |
duke@435 | 1276 | } |
duke@435 | 1277 | |
duke@435 | 1278 | HeapWord* |
duke@435 | 1279 | CompactibleFreeListSpace::getChunkFromLinearAllocBlock(LinearAllocBlock *blk, |
duke@435 | 1280 | size_t size) { |
duke@435 | 1281 | assert_locked(); |
duke@435 | 1282 | assert(size >= MinChunkSize, "too small"); |
duke@435 | 1283 | HeapWord* res = NULL; |
duke@435 | 1284 | // Try to do linear allocation from blk, making sure that |
duke@435 | 1285 | if (blk->_word_size == 0) { |
duke@435 | 1286 | // We have probably been unable to fill this either in the prologue or |
duke@435 | 1287 | // when it was exhausted at the last linear allocation. Bail out until |
duke@435 | 1288 | // next time. |
duke@435 | 1289 | assert(blk->_ptr == NULL, "consistency check"); |
duke@435 | 1290 | return NULL; |
duke@435 | 1291 | } |
duke@435 | 1292 | assert(blk->_word_size != 0 && blk->_ptr != NULL, "consistency check"); |
duke@435 | 1293 | res = getChunkFromLinearAllocBlockRemainder(blk, size); |
duke@435 | 1294 | if (res != NULL) return res; |
duke@435 | 1295 | |
duke@435 | 1296 | // about to exhaust this linear allocation block |
duke@435 | 1297 | if (blk->_word_size == size) { // exactly satisfied |
duke@435 | 1298 | res = blk->_ptr; |
duke@435 | 1299 | _bt.allocated(res, blk->_word_size); |
duke@435 | 1300 | } else if (size + MinChunkSize <= blk->_refillSize) { |
duke@435 | 1301 | // Update _unallocated_block if the size is such that chunk would be |
duke@435 | 1302 | // returned to the indexed free list. All other chunks in the indexed |
duke@435 | 1303 | // free lists are allocated from the dictionary so that _unallocated_block |
duke@435 | 1304 | // has already been adjusted for them. Do it here so that the cost |
duke@435 | 1305 | // for all chunks added back to the indexed free lists. |
duke@435 | 1306 | if (blk->_word_size < SmallForDictionary) { |
duke@435 | 1307 | _bt.allocated(blk->_ptr, blk->_word_size); |
duke@435 | 1308 | } |
duke@435 | 1309 | // Return the chunk that isn't big enough, and then refill below. |
duke@435 | 1310 | addChunkToFreeLists(blk->_ptr, blk->_word_size); |
duke@435 | 1311 | _bt.verify_single_block(blk->_ptr, (blk->_ptr + blk->_word_size)); |
duke@435 | 1312 | // Don't keep statistics on adding back chunk from a LinAB. |
duke@435 | 1313 | } else { |
duke@435 | 1314 | // A refilled block would not satisfy the request. |
duke@435 | 1315 | return NULL; |
duke@435 | 1316 | } |
duke@435 | 1317 | |
duke@435 | 1318 | blk->_ptr = NULL; blk->_word_size = 0; |
duke@435 | 1319 | refillLinearAllocBlock(blk); |
duke@435 | 1320 | assert(blk->_ptr == NULL || blk->_word_size >= size + MinChunkSize, |
duke@435 | 1321 | "block was replenished"); |
duke@435 | 1322 | if (res != NULL) { |
duke@435 | 1323 | splitBirth(size); |
duke@435 | 1324 | repairLinearAllocBlock(blk); |
duke@435 | 1325 | } else if (blk->_ptr != NULL) { |
duke@435 | 1326 | res = blk->_ptr; |
duke@435 | 1327 | size_t blk_size = blk->_word_size; |
duke@435 | 1328 | blk->_word_size -= size; |
duke@435 | 1329 | blk->_ptr += size; |
duke@435 | 1330 | splitBirth(size); |
duke@435 | 1331 | repairLinearAllocBlock(blk); |
duke@435 | 1332 | // Update BOT last so that other (parallel) GC threads see a consistent |
duke@435 | 1333 | // view of the BOT and free blocks. |
duke@435 | 1334 | // Above must occur before BOT is updated below. |
duke@435 | 1335 | _bt.split_block(res, blk_size, size); // adjust block offset table |
duke@435 | 1336 | } |
duke@435 | 1337 | return res; |
duke@435 | 1338 | } |
duke@435 | 1339 | |
duke@435 | 1340 | HeapWord* CompactibleFreeListSpace::getChunkFromLinearAllocBlockRemainder( |
duke@435 | 1341 | LinearAllocBlock* blk, |
duke@435 | 1342 | size_t size) { |
duke@435 | 1343 | assert_locked(); |
duke@435 | 1344 | assert(size >= MinChunkSize, "too small"); |
duke@435 | 1345 | |
duke@435 | 1346 | HeapWord* res = NULL; |
duke@435 | 1347 | // This is the common case. Keep it simple. |
duke@435 | 1348 | if (blk->_word_size >= size + MinChunkSize) { |
duke@435 | 1349 | assert(blk->_ptr != NULL, "consistency check"); |
duke@435 | 1350 | res = blk->_ptr; |
duke@435 | 1351 | // Note that the BOT is up-to-date for the linAB before allocation. It |
duke@435 | 1352 | // indicates the start of the linAB. The split_block() updates the |
duke@435 | 1353 | // BOT for the linAB after the allocation (indicates the start of the |
duke@435 | 1354 | // next chunk to be allocated). |
duke@435 | 1355 | size_t blk_size = blk->_word_size; |
duke@435 | 1356 | blk->_word_size -= size; |
duke@435 | 1357 | blk->_ptr += size; |
duke@435 | 1358 | splitBirth(size); |
duke@435 | 1359 | repairLinearAllocBlock(blk); |
duke@435 | 1360 | // Update BOT last so that other (parallel) GC threads see a consistent |
duke@435 | 1361 | // view of the BOT and free blocks. |
duke@435 | 1362 | // Above must occur before BOT is updated below. |
duke@435 | 1363 | _bt.split_block(res, blk_size, size); // adjust block offset table |
duke@435 | 1364 | _bt.allocated(res, size); |
duke@435 | 1365 | } |
duke@435 | 1366 | return res; |
duke@435 | 1367 | } |
duke@435 | 1368 | |
duke@435 | 1369 | FreeChunk* |
duke@435 | 1370 | CompactibleFreeListSpace::getChunkFromIndexedFreeList(size_t size) { |
duke@435 | 1371 | assert_locked(); |
duke@435 | 1372 | assert(size < SmallForDictionary, "just checking"); |
duke@435 | 1373 | FreeChunk* res; |
duke@435 | 1374 | res = _indexedFreeList[size].getChunkAtHead(); |
duke@435 | 1375 | if (res == NULL) { |
duke@435 | 1376 | res = getChunkFromIndexedFreeListHelper(size); |
duke@435 | 1377 | } |
duke@435 | 1378 | _bt.verify_not_unallocated((HeapWord*) res, size); |
duke@435 | 1379 | return res; |
duke@435 | 1380 | } |
duke@435 | 1381 | |
duke@435 | 1382 | FreeChunk* |
duke@435 | 1383 | CompactibleFreeListSpace::getChunkFromIndexedFreeListHelper(size_t size) { |
duke@435 | 1384 | assert_locked(); |
duke@435 | 1385 | FreeChunk* fc = NULL; |
duke@435 | 1386 | if (size < SmallForDictionary) { |
duke@435 | 1387 | assert(_indexedFreeList[size].head() == NULL || |
duke@435 | 1388 | _indexedFreeList[size].surplus() <= 0, |
duke@435 | 1389 | "List for this size should be empty or under populated"); |
duke@435 | 1390 | // Try best fit in exact lists before replenishing the list |
duke@435 | 1391 | if (!bestFitFirst() || (fc = bestFitSmall(size)) == NULL) { |
duke@435 | 1392 | // Replenish list. |
duke@435 | 1393 | // |
duke@435 | 1394 | // Things tried that failed. |
duke@435 | 1395 | // Tried allocating out of the two LinAB's first before |
duke@435 | 1396 | // replenishing lists. |
duke@435 | 1397 | // Tried small linAB of size 256 (size in indexed list) |
duke@435 | 1398 | // and replenishing indexed lists from the small linAB. |
duke@435 | 1399 | // |
duke@435 | 1400 | FreeChunk* newFc = NULL; |
duke@435 | 1401 | size_t replenish_size = CMSIndexedFreeListReplenish * size; |
duke@435 | 1402 | if (replenish_size < SmallForDictionary) { |
duke@435 | 1403 | // Do not replenish from an underpopulated size. |
duke@435 | 1404 | if (_indexedFreeList[replenish_size].surplus() > 0 && |
duke@435 | 1405 | _indexedFreeList[replenish_size].head() != NULL) { |
duke@435 | 1406 | newFc = |
duke@435 | 1407 | _indexedFreeList[replenish_size].getChunkAtHead(); |
duke@435 | 1408 | } else { |
duke@435 | 1409 | newFc = bestFitSmall(replenish_size); |
duke@435 | 1410 | } |
duke@435 | 1411 | } |
duke@435 | 1412 | if (newFc != NULL) { |
duke@435 | 1413 | splitDeath(replenish_size); |
duke@435 | 1414 | } else if (replenish_size > size) { |
duke@435 | 1415 | assert(CMSIndexedFreeListReplenish > 1, "ctl pt invariant"); |
duke@435 | 1416 | newFc = |
duke@435 | 1417 | getChunkFromIndexedFreeListHelper(replenish_size); |
duke@435 | 1418 | } |
duke@435 | 1419 | if (newFc != NULL) { |
duke@435 | 1420 | assert(newFc->size() == replenish_size, "Got wrong size"); |
duke@435 | 1421 | size_t i; |
duke@435 | 1422 | FreeChunk *curFc, *nextFc; |
duke@435 | 1423 | // carve up and link blocks 0, ..., CMSIndexedFreeListReplenish - 2 |
duke@435 | 1424 | // The last chunk is not added to the lists but is returned as the |
duke@435 | 1425 | // free chunk. |
duke@435 | 1426 | for (curFc = newFc, nextFc = (FreeChunk*)((HeapWord*)curFc + size), |
duke@435 | 1427 | i = 0; |
duke@435 | 1428 | i < (CMSIndexedFreeListReplenish - 1); |
duke@435 | 1429 | curFc = nextFc, nextFc = (FreeChunk*)((HeapWord*)nextFc + size), |
duke@435 | 1430 | i++) { |
duke@435 | 1431 | curFc->setSize(size); |
duke@435 | 1432 | // Don't record this as a return in order to try and |
duke@435 | 1433 | // determine the "returns" from a GC. |
duke@435 | 1434 | _bt.verify_not_unallocated((HeapWord*) fc, size); |
duke@435 | 1435 | _indexedFreeList[size].returnChunkAtTail(curFc, false); |
duke@435 | 1436 | _bt.mark_block((HeapWord*)curFc, size); |
duke@435 | 1437 | splitBirth(size); |
duke@435 | 1438 | // Don't record the initial population of the indexed list |
duke@435 | 1439 | // as a split birth. |
duke@435 | 1440 | } |
duke@435 | 1441 | |
duke@435 | 1442 | // check that the arithmetic was OK above |
duke@435 | 1443 | assert((HeapWord*)nextFc == (HeapWord*)newFc + replenish_size, |
duke@435 | 1444 | "inconsistency in carving newFc"); |
duke@435 | 1445 | curFc->setSize(size); |
duke@435 | 1446 | _bt.mark_block((HeapWord*)curFc, size); |
duke@435 | 1447 | splitBirth(size); |
duke@435 | 1448 | return curFc; |
duke@435 | 1449 | } |
duke@435 | 1450 | } |
duke@435 | 1451 | } else { |
duke@435 | 1452 | // Get a free chunk from the free chunk dictionary to be returned to |
duke@435 | 1453 | // replenish the indexed free list. |
duke@435 | 1454 | fc = getChunkFromDictionaryExact(size); |
duke@435 | 1455 | } |
duke@435 | 1456 | assert(fc == NULL || fc->isFree(), "Should be returning a free chunk"); |
duke@435 | 1457 | return fc; |
duke@435 | 1458 | } |
duke@435 | 1459 | |
duke@435 | 1460 | FreeChunk* |
duke@435 | 1461 | CompactibleFreeListSpace::getChunkFromDictionary(size_t size) { |
duke@435 | 1462 | assert_locked(); |
duke@435 | 1463 | FreeChunk* fc = _dictionary->getChunk(size); |
duke@435 | 1464 | if (fc == NULL) { |
duke@435 | 1465 | return NULL; |
duke@435 | 1466 | } |
duke@435 | 1467 | _bt.allocated((HeapWord*)fc, fc->size()); |
duke@435 | 1468 | if (fc->size() >= size + MinChunkSize) { |
duke@435 | 1469 | fc = splitChunkAndReturnRemainder(fc, size); |
duke@435 | 1470 | } |
duke@435 | 1471 | assert(fc->size() >= size, "chunk too small"); |
duke@435 | 1472 | assert(fc->size() < size + MinChunkSize, "chunk too big"); |
duke@435 | 1473 | _bt.verify_single_block((HeapWord*)fc, fc->size()); |
duke@435 | 1474 | return fc; |
duke@435 | 1475 | } |
duke@435 | 1476 | |
duke@435 | 1477 | FreeChunk* |
duke@435 | 1478 | CompactibleFreeListSpace::getChunkFromDictionaryExact(size_t size) { |
duke@435 | 1479 | assert_locked(); |
duke@435 | 1480 | FreeChunk* fc = _dictionary->getChunk(size); |
duke@435 | 1481 | if (fc == NULL) { |
duke@435 | 1482 | return fc; |
duke@435 | 1483 | } |
duke@435 | 1484 | _bt.allocated((HeapWord*)fc, fc->size()); |
duke@435 | 1485 | if (fc->size() == size) { |
duke@435 | 1486 | _bt.verify_single_block((HeapWord*)fc, size); |
duke@435 | 1487 | return fc; |
duke@435 | 1488 | } |
duke@435 | 1489 | assert(fc->size() > size, "getChunk() guarantee"); |
duke@435 | 1490 | if (fc->size() < size + MinChunkSize) { |
duke@435 | 1491 | // Return the chunk to the dictionary and go get a bigger one. |
duke@435 | 1492 | returnChunkToDictionary(fc); |
duke@435 | 1493 | fc = _dictionary->getChunk(size + MinChunkSize); |
duke@435 | 1494 | if (fc == NULL) { |
duke@435 | 1495 | return NULL; |
duke@435 | 1496 | } |
duke@435 | 1497 | _bt.allocated((HeapWord*)fc, fc->size()); |
duke@435 | 1498 | } |
duke@435 | 1499 | assert(fc->size() >= size + MinChunkSize, "tautology"); |
duke@435 | 1500 | fc = splitChunkAndReturnRemainder(fc, size); |
duke@435 | 1501 | assert(fc->size() == size, "chunk is wrong size"); |
duke@435 | 1502 | _bt.verify_single_block((HeapWord*)fc, size); |
duke@435 | 1503 | return fc; |
duke@435 | 1504 | } |
duke@435 | 1505 | |
duke@435 | 1506 | void |
duke@435 | 1507 | CompactibleFreeListSpace::returnChunkToDictionary(FreeChunk* chunk) { |
duke@435 | 1508 | assert_locked(); |
duke@435 | 1509 | |
duke@435 | 1510 | size_t size = chunk->size(); |
duke@435 | 1511 | _bt.verify_single_block((HeapWord*)chunk, size); |
duke@435 | 1512 | // adjust _unallocated_block downward, as necessary |
duke@435 | 1513 | _bt.freed((HeapWord*)chunk, size); |
duke@435 | 1514 | _dictionary->returnChunk(chunk); |
duke@435 | 1515 | } |
duke@435 | 1516 | |
duke@435 | 1517 | void |
duke@435 | 1518 | CompactibleFreeListSpace::returnChunkToFreeList(FreeChunk* fc) { |
duke@435 | 1519 | assert_locked(); |
duke@435 | 1520 | size_t size = fc->size(); |
duke@435 | 1521 | _bt.verify_single_block((HeapWord*) fc, size); |
duke@435 | 1522 | _bt.verify_not_unallocated((HeapWord*) fc, size); |
duke@435 | 1523 | if (_adaptive_freelists) { |
duke@435 | 1524 | _indexedFreeList[size].returnChunkAtTail(fc); |
duke@435 | 1525 | } else { |
duke@435 | 1526 | _indexedFreeList[size].returnChunkAtHead(fc); |
duke@435 | 1527 | } |
duke@435 | 1528 | } |
duke@435 | 1529 | |
duke@435 | 1530 | // Add chunk to end of last block -- if it's the largest |
duke@435 | 1531 | // block -- and update BOT and census data. We would |
duke@435 | 1532 | // of course have preferred to coalesce it with the |
duke@435 | 1533 | // last block, but it's currently less expensive to find the |
duke@435 | 1534 | // largest block than it is to find the last. |
duke@435 | 1535 | void |
duke@435 | 1536 | CompactibleFreeListSpace::addChunkToFreeListsAtEndRecordingStats( |
duke@435 | 1537 | HeapWord* chunk, size_t size) { |
duke@435 | 1538 | // check that the chunk does lie in this space! |
duke@435 | 1539 | assert(chunk != NULL && is_in_reserved(chunk), "Not in this space!"); |
duke@435 | 1540 | assert_locked(); |
duke@435 | 1541 | // One of the parallel gc task threads may be here |
duke@435 | 1542 | // whilst others are allocating. |
duke@435 | 1543 | Mutex* lock = NULL; |
duke@435 | 1544 | if (ParallelGCThreads != 0) { |
duke@435 | 1545 | lock = &_parDictionaryAllocLock; |
duke@435 | 1546 | } |
duke@435 | 1547 | FreeChunk* ec; |
duke@435 | 1548 | { |
duke@435 | 1549 | MutexLockerEx x(lock, Mutex::_no_safepoint_check_flag); |
duke@435 | 1550 | ec = dictionary()->findLargestDict(); // get largest block |
duke@435 | 1551 | if (ec != NULL && ec->end() == chunk) { |
duke@435 | 1552 | // It's a coterminal block - we can coalesce. |
duke@435 | 1553 | size_t old_size = ec->size(); |
duke@435 | 1554 | coalDeath(old_size); |
duke@435 | 1555 | removeChunkFromDictionary(ec); |
duke@435 | 1556 | size += old_size; |
duke@435 | 1557 | } else { |
duke@435 | 1558 | ec = (FreeChunk*)chunk; |
duke@435 | 1559 | } |
duke@435 | 1560 | } |
duke@435 | 1561 | ec->setSize(size); |
duke@435 | 1562 | debug_only(ec->mangleFreed(size)); |
duke@435 | 1563 | if (size < SmallForDictionary) { |
duke@435 | 1564 | lock = _indexedFreeListParLocks[size]; |
duke@435 | 1565 | } |
duke@435 | 1566 | MutexLockerEx x(lock, Mutex::_no_safepoint_check_flag); |
duke@435 | 1567 | addChunkAndRepairOffsetTable((HeapWord*)ec, size, true); |
duke@435 | 1568 | // record the birth under the lock since the recording involves |
duke@435 | 1569 | // manipulation of the list on which the chunk lives and |
duke@435 | 1570 | // if the chunk is allocated and is the last on the list, |
duke@435 | 1571 | // the list can go away. |
duke@435 | 1572 | coalBirth(size); |
duke@435 | 1573 | } |
duke@435 | 1574 | |
duke@435 | 1575 | void |
duke@435 | 1576 | CompactibleFreeListSpace::addChunkToFreeLists(HeapWord* chunk, |
duke@435 | 1577 | size_t size) { |
duke@435 | 1578 | // check that the chunk does lie in this space! |
duke@435 | 1579 | assert(chunk != NULL && is_in_reserved(chunk), "Not in this space!"); |
duke@435 | 1580 | assert_locked(); |
duke@435 | 1581 | _bt.verify_single_block(chunk, size); |
duke@435 | 1582 | |
duke@435 | 1583 | FreeChunk* fc = (FreeChunk*) chunk; |
duke@435 | 1584 | fc->setSize(size); |
duke@435 | 1585 | debug_only(fc->mangleFreed(size)); |
duke@435 | 1586 | if (size < SmallForDictionary) { |
duke@435 | 1587 | returnChunkToFreeList(fc); |
duke@435 | 1588 | } else { |
duke@435 | 1589 | returnChunkToDictionary(fc); |
duke@435 | 1590 | } |
duke@435 | 1591 | } |
duke@435 | 1592 | |
duke@435 | 1593 | void |
duke@435 | 1594 | CompactibleFreeListSpace::addChunkAndRepairOffsetTable(HeapWord* chunk, |
duke@435 | 1595 | size_t size, bool coalesced) { |
duke@435 | 1596 | assert_locked(); |
duke@435 | 1597 | assert(chunk != NULL, "null chunk"); |
duke@435 | 1598 | if (coalesced) { |
duke@435 | 1599 | // repair BOT |
duke@435 | 1600 | _bt.single_block(chunk, size); |
duke@435 | 1601 | } |
duke@435 | 1602 | addChunkToFreeLists(chunk, size); |
duke@435 | 1603 | } |
duke@435 | 1604 | |
duke@435 | 1605 | // We _must_ find the purported chunk on our free lists; |
duke@435 | 1606 | // we assert if we don't. |
duke@435 | 1607 | void |
duke@435 | 1608 | CompactibleFreeListSpace::removeFreeChunkFromFreeLists(FreeChunk* fc) { |
duke@435 | 1609 | size_t size = fc->size(); |
duke@435 | 1610 | assert_locked(); |
duke@435 | 1611 | debug_only(verifyFreeLists()); |
duke@435 | 1612 | if (size < SmallForDictionary) { |
duke@435 | 1613 | removeChunkFromIndexedFreeList(fc); |
duke@435 | 1614 | } else { |
duke@435 | 1615 | removeChunkFromDictionary(fc); |
duke@435 | 1616 | } |
duke@435 | 1617 | _bt.verify_single_block((HeapWord*)fc, size); |
duke@435 | 1618 | debug_only(verifyFreeLists()); |
duke@435 | 1619 | } |
duke@435 | 1620 | |
duke@435 | 1621 | void |
duke@435 | 1622 | CompactibleFreeListSpace::removeChunkFromDictionary(FreeChunk* fc) { |
duke@435 | 1623 | size_t size = fc->size(); |
duke@435 | 1624 | assert_locked(); |
duke@435 | 1625 | assert(fc != NULL, "null chunk"); |
duke@435 | 1626 | _bt.verify_single_block((HeapWord*)fc, size); |
duke@435 | 1627 | _dictionary->removeChunk(fc); |
duke@435 | 1628 | // adjust _unallocated_block upward, as necessary |
duke@435 | 1629 | _bt.allocated((HeapWord*)fc, size); |
duke@435 | 1630 | } |
duke@435 | 1631 | |
duke@435 | 1632 | void |
duke@435 | 1633 | CompactibleFreeListSpace::removeChunkFromIndexedFreeList(FreeChunk* fc) { |
duke@435 | 1634 | assert_locked(); |
duke@435 | 1635 | size_t size = fc->size(); |
duke@435 | 1636 | _bt.verify_single_block((HeapWord*)fc, size); |
duke@435 | 1637 | NOT_PRODUCT( |
duke@435 | 1638 | if (FLSVerifyIndexTable) { |
duke@435 | 1639 | verifyIndexedFreeList(size); |
duke@435 | 1640 | } |
duke@435 | 1641 | ) |
duke@435 | 1642 | _indexedFreeList[size].removeChunk(fc); |
duke@435 | 1643 | debug_only(fc->clearNext()); |
duke@435 | 1644 | debug_only(fc->clearPrev()); |
duke@435 | 1645 | NOT_PRODUCT( |
duke@435 | 1646 | if (FLSVerifyIndexTable) { |
duke@435 | 1647 | verifyIndexedFreeList(size); |
duke@435 | 1648 | } |
duke@435 | 1649 | ) |
duke@435 | 1650 | } |
duke@435 | 1651 | |
duke@435 | 1652 | FreeChunk* CompactibleFreeListSpace::bestFitSmall(size_t numWords) { |
duke@435 | 1653 | /* A hint is the next larger size that has a surplus. |
duke@435 | 1654 | Start search at a size large enough to guarantee that |
duke@435 | 1655 | the excess is >= MIN_CHUNK. */ |
duke@435 | 1656 | size_t start = align_object_size(numWords + MinChunkSize); |
duke@435 | 1657 | if (start < IndexSetSize) { |
duke@435 | 1658 | FreeList* it = _indexedFreeList; |
duke@435 | 1659 | size_t hint = _indexedFreeList[start].hint(); |
duke@435 | 1660 | while (hint < IndexSetSize) { |
duke@435 | 1661 | assert(hint % MinObjAlignment == 0, "hint should be aligned"); |
duke@435 | 1662 | FreeList *fl = &_indexedFreeList[hint]; |
duke@435 | 1663 | if (fl->surplus() > 0 && fl->head() != NULL) { |
duke@435 | 1664 | // Found a list with surplus, reset original hint |
duke@435 | 1665 | // and split out a free chunk which is returned. |
duke@435 | 1666 | _indexedFreeList[start].set_hint(hint); |
duke@435 | 1667 | FreeChunk* res = getFromListGreater(fl, numWords); |
duke@435 | 1668 | assert(res == NULL || res->isFree(), |
duke@435 | 1669 | "Should be returning a free chunk"); |
duke@435 | 1670 | return res; |
duke@435 | 1671 | } |
duke@435 | 1672 | hint = fl->hint(); /* keep looking */ |
duke@435 | 1673 | } |
duke@435 | 1674 | /* None found. */ |
duke@435 | 1675 | it[start].set_hint(IndexSetSize); |
duke@435 | 1676 | } |
duke@435 | 1677 | return NULL; |
duke@435 | 1678 | } |
duke@435 | 1679 | |
duke@435 | 1680 | /* Requires fl->size >= numWords + MinChunkSize */ |
duke@435 | 1681 | FreeChunk* CompactibleFreeListSpace::getFromListGreater(FreeList* fl, |
duke@435 | 1682 | size_t numWords) { |
duke@435 | 1683 | FreeChunk *curr = fl->head(); |
duke@435 | 1684 | size_t oldNumWords = curr->size(); |
duke@435 | 1685 | assert(numWords >= MinChunkSize, "Word size is too small"); |
duke@435 | 1686 | assert(curr != NULL, "List is empty"); |
duke@435 | 1687 | assert(oldNumWords >= numWords + MinChunkSize, |
duke@435 | 1688 | "Size of chunks in the list is too small"); |
duke@435 | 1689 | |
duke@435 | 1690 | fl->removeChunk(curr); |
duke@435 | 1691 | // recorded indirectly by splitChunkAndReturnRemainder - |
duke@435 | 1692 | // smallSplit(oldNumWords, numWords); |
duke@435 | 1693 | FreeChunk* new_chunk = splitChunkAndReturnRemainder(curr, numWords); |
duke@435 | 1694 | // Does anything have to be done for the remainder in terms of |
duke@435 | 1695 | // fixing the card table? |
duke@435 | 1696 | assert(new_chunk == NULL || new_chunk->isFree(), |
duke@435 | 1697 | "Should be returning a free chunk"); |
duke@435 | 1698 | return new_chunk; |
duke@435 | 1699 | } |
duke@435 | 1700 | |
duke@435 | 1701 | FreeChunk* |
duke@435 | 1702 | CompactibleFreeListSpace::splitChunkAndReturnRemainder(FreeChunk* chunk, |
duke@435 | 1703 | size_t new_size) { |
duke@435 | 1704 | assert_locked(); |
duke@435 | 1705 | size_t size = chunk->size(); |
duke@435 | 1706 | assert(size > new_size, "Split from a smaller block?"); |
duke@435 | 1707 | assert(is_aligned(chunk), "alignment problem"); |
duke@435 | 1708 | assert(size == adjustObjectSize(size), "alignment problem"); |
duke@435 | 1709 | size_t rem_size = size - new_size; |
duke@435 | 1710 | assert(rem_size == adjustObjectSize(rem_size), "alignment problem"); |
duke@435 | 1711 | assert(rem_size >= MinChunkSize, "Free chunk smaller than minimum"); |
duke@435 | 1712 | FreeChunk* ffc = (FreeChunk*)((HeapWord*)chunk + new_size); |
duke@435 | 1713 | assert(is_aligned(ffc), "alignment problem"); |
duke@435 | 1714 | ffc->setSize(rem_size); |
duke@435 | 1715 | ffc->linkNext(NULL); |
duke@435 | 1716 | ffc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. |
duke@435 | 1717 | // Above must occur before BOT is updated below. |
duke@435 | 1718 | // adjust block offset table |
duke@435 | 1719 | _bt.split_block((HeapWord*)chunk, chunk->size(), new_size); |
duke@435 | 1720 | if (rem_size < SmallForDictionary) { |
duke@435 | 1721 | bool is_par = (SharedHeap::heap()->n_par_threads() > 0); |
duke@435 | 1722 | if (is_par) _indexedFreeListParLocks[rem_size]->lock(); |
duke@435 | 1723 | returnChunkToFreeList(ffc); |
duke@435 | 1724 | split(size, rem_size); |
duke@435 | 1725 | if (is_par) _indexedFreeListParLocks[rem_size]->unlock(); |
duke@435 | 1726 | } else { |
duke@435 | 1727 | returnChunkToDictionary(ffc); |
duke@435 | 1728 | split(size ,rem_size); |
duke@435 | 1729 | } |
duke@435 | 1730 | chunk->setSize(new_size); |
duke@435 | 1731 | return chunk; |
duke@435 | 1732 | } |
duke@435 | 1733 | |
duke@435 | 1734 | void |
duke@435 | 1735 | CompactibleFreeListSpace::sweep_completed() { |
duke@435 | 1736 | // Now that space is probably plentiful, refill linear |
duke@435 | 1737 | // allocation blocks as needed. |
duke@435 | 1738 | refillLinearAllocBlocksIfNeeded(); |
duke@435 | 1739 | } |
duke@435 | 1740 | |
duke@435 | 1741 | void |
duke@435 | 1742 | CompactibleFreeListSpace::gc_prologue() { |
duke@435 | 1743 | assert_locked(); |
duke@435 | 1744 | if (PrintFLSStatistics != 0) { |
duke@435 | 1745 | gclog_or_tty->print("Before GC:\n"); |
duke@435 | 1746 | reportFreeListStatistics(); |
duke@435 | 1747 | } |
duke@435 | 1748 | refillLinearAllocBlocksIfNeeded(); |
duke@435 | 1749 | } |
duke@435 | 1750 | |
duke@435 | 1751 | void |
duke@435 | 1752 | CompactibleFreeListSpace::gc_epilogue() { |
duke@435 | 1753 | assert_locked(); |
duke@435 | 1754 | if (PrintGCDetails && Verbose && !_adaptive_freelists) { |
duke@435 | 1755 | if (_smallLinearAllocBlock._word_size == 0) |
duke@435 | 1756 | warning("CompactibleFreeListSpace(epilogue):: Linear allocation failure"); |
duke@435 | 1757 | } |
duke@435 | 1758 | assert(_promoInfo.noPromotions(), "_promoInfo inconsistency"); |
duke@435 | 1759 | _promoInfo.stopTrackingPromotions(); |
duke@435 | 1760 | repairLinearAllocationBlocks(); |
duke@435 | 1761 | // Print Space's stats |
duke@435 | 1762 | if (PrintFLSStatistics != 0) { |
duke@435 | 1763 | gclog_or_tty->print("After GC:\n"); |
duke@435 | 1764 | reportFreeListStatistics(); |
duke@435 | 1765 | } |
duke@435 | 1766 | } |
duke@435 | 1767 | |
duke@435 | 1768 | // Iteration support, mostly delegated from a CMS generation |
duke@435 | 1769 | |
duke@435 | 1770 | void CompactibleFreeListSpace::save_marks() { |
duke@435 | 1771 | // mark the "end" of the used space at the time of this call; |
duke@435 | 1772 | // note, however, that promoted objects from this point |
duke@435 | 1773 | // on are tracked in the _promoInfo below. |
duke@435 | 1774 | set_saved_mark_word(BlockOffsetArrayUseUnallocatedBlock ? |
duke@435 | 1775 | unallocated_block() : end()); |
duke@435 | 1776 | // inform allocator that promotions should be tracked. |
duke@435 | 1777 | assert(_promoInfo.noPromotions(), "_promoInfo inconsistency"); |
duke@435 | 1778 | _promoInfo.startTrackingPromotions(); |
duke@435 | 1779 | } |
duke@435 | 1780 | |
duke@435 | 1781 | bool CompactibleFreeListSpace::no_allocs_since_save_marks() { |
duke@435 | 1782 | assert(_promoInfo.tracking(), "No preceding save_marks?"); |
duke@435 | 1783 | guarantee(SharedHeap::heap()->n_par_threads() == 0, |
duke@435 | 1784 | "Shouldn't be called (yet) during parallel part of gc."); |
duke@435 | 1785 | return _promoInfo.noPromotions(); |
duke@435 | 1786 | } |
duke@435 | 1787 | |
duke@435 | 1788 | #define CFLS_OOP_SINCE_SAVE_MARKS_DEFN(OopClosureType, nv_suffix) \ |
duke@435 | 1789 | \ |
duke@435 | 1790 | void CompactibleFreeListSpace:: \ |
duke@435 | 1791 | oop_since_save_marks_iterate##nv_suffix(OopClosureType* blk) { \ |
duke@435 | 1792 | assert(SharedHeap::heap()->n_par_threads() == 0, \ |
duke@435 | 1793 | "Shouldn't be called (yet) during parallel part of gc."); \ |
duke@435 | 1794 | _promoInfo.promoted_oops_iterate##nv_suffix(blk); \ |
duke@435 | 1795 | /* \ |
duke@435 | 1796 | * This also restores any displaced headers and removes the elements from \ |
duke@435 | 1797 | * the iteration set as they are processed, so that we have a clean slate \ |
duke@435 | 1798 | * at the end of the iteration. Note, thus, that if new objects are \ |
duke@435 | 1799 | * promoted as a result of the iteration they are iterated over as well. \ |
duke@435 | 1800 | */ \ |
duke@435 | 1801 | assert(_promoInfo.noPromotions(), "_promoInfo inconsistency"); \ |
duke@435 | 1802 | } |
duke@435 | 1803 | |
duke@435 | 1804 | ALL_SINCE_SAVE_MARKS_CLOSURES(CFLS_OOP_SINCE_SAVE_MARKS_DEFN) |
duke@435 | 1805 | |
duke@435 | 1806 | ////////////////////////////////////////////////////////////////////////////// |
duke@435 | 1807 | // We go over the list of promoted objects, removing each from the list, |
duke@435 | 1808 | // and applying the closure (this may, in turn, add more elements to |
duke@435 | 1809 | // the tail of the promoted list, and these newly added objects will |
duke@435 | 1810 | // also be processed) until the list is empty. |
duke@435 | 1811 | // To aid verification and debugging, in the non-product builds |
duke@435 | 1812 | // we actually forward _promoHead each time we process a promoted oop. |
duke@435 | 1813 | // Note that this is not necessary in general (i.e. when we don't need to |
duke@435 | 1814 | // call PromotionInfo::verify()) because oop_iterate can only add to the |
duke@435 | 1815 | // end of _promoTail, and never needs to look at _promoHead. |
duke@435 | 1816 | |
duke@435 | 1817 | #define PROMOTED_OOPS_ITERATE_DEFN(OopClosureType, nv_suffix) \ |
duke@435 | 1818 | \ |
duke@435 | 1819 | void PromotionInfo::promoted_oops_iterate##nv_suffix(OopClosureType* cl) { \ |
duke@435 | 1820 | NOT_PRODUCT(verify()); \ |
duke@435 | 1821 | PromotedObject *curObj, *nextObj; \ |
duke@435 | 1822 | for (curObj = _promoHead; curObj != NULL; curObj = nextObj) { \ |
duke@435 | 1823 | if ((nextObj = curObj->next()) == NULL) { \ |
duke@435 | 1824 | /* protect ourselves against additions due to closure application \ |
duke@435 | 1825 | below by resetting the list. */ \ |
duke@435 | 1826 | assert(_promoTail == curObj, "Should have been the tail"); \ |
duke@435 | 1827 | _promoHead = _promoTail = NULL; \ |
duke@435 | 1828 | } \ |
duke@435 | 1829 | if (curObj->hasDisplacedMark()) { \ |
duke@435 | 1830 | /* restore displaced header */ \ |
duke@435 | 1831 | oop(curObj)->set_mark(nextDisplacedHeader()); \ |
duke@435 | 1832 | } else { \ |
duke@435 | 1833 | /* restore prototypical header */ \ |
duke@435 | 1834 | oop(curObj)->init_mark(); \ |
duke@435 | 1835 | } \ |
duke@435 | 1836 | /* The "promoted_mark" should now not be set */ \ |
duke@435 | 1837 | assert(!curObj->hasPromotedMark(), \ |
duke@435 | 1838 | "Should have been cleared by restoring displaced mark-word"); \ |
duke@435 | 1839 | NOT_PRODUCT(_promoHead = nextObj); \ |
duke@435 | 1840 | if (cl != NULL) oop(curObj)->oop_iterate(cl); \ |
duke@435 | 1841 | if (nextObj == NULL) { /* start at head of list reset above */ \ |
duke@435 | 1842 | nextObj = _promoHead; \ |
duke@435 | 1843 | } \ |
duke@435 | 1844 | } \ |
duke@435 | 1845 | assert(noPromotions(), "post-condition violation"); \ |
duke@435 | 1846 | assert(_promoHead == NULL && _promoTail == NULL, "emptied promoted list");\ |
duke@435 | 1847 | assert(_spoolHead == _spoolTail, "emptied spooling buffers"); \ |
duke@435 | 1848 | assert(_firstIndex == _nextIndex, "empty buffer"); \ |
duke@435 | 1849 | } |
duke@435 | 1850 | |
duke@435 | 1851 | // This should have been ALL_SINCE_...() just like the others, |
duke@435 | 1852 | // but, because the body of the method above is somehwat longer, |
duke@435 | 1853 | // the MSVC compiler cannot cope; as a workaround, we split the |
duke@435 | 1854 | // macro into its 3 constituent parts below (see original macro |
duke@435 | 1855 | // definition in specializedOopClosures.hpp). |
duke@435 | 1856 | SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES_YOUNG(PROMOTED_OOPS_ITERATE_DEFN) |
duke@435 | 1857 | PROMOTED_OOPS_ITERATE_DEFN(OopsInGenClosure,_v) |
duke@435 | 1858 | |
duke@435 | 1859 | |
duke@435 | 1860 | void CompactibleFreeListSpace::object_iterate_since_last_GC(ObjectClosure* cl) { |
duke@435 | 1861 | // ugghh... how would one do this efficiently for a non-contiguous space? |
duke@435 | 1862 | guarantee(false, "NYI"); |
duke@435 | 1863 | } |
duke@435 | 1864 | |
ysr@447 | 1865 | bool CompactibleFreeListSpace::linearAllocationWouldFail() const { |
duke@435 | 1866 | return _smallLinearAllocBlock._word_size == 0; |
duke@435 | 1867 | } |
duke@435 | 1868 | |
duke@435 | 1869 | void CompactibleFreeListSpace::repairLinearAllocationBlocks() { |
duke@435 | 1870 | // Fix up linear allocation blocks to look like free blocks |
duke@435 | 1871 | repairLinearAllocBlock(&_smallLinearAllocBlock); |
duke@435 | 1872 | } |
duke@435 | 1873 | |
duke@435 | 1874 | void CompactibleFreeListSpace::repairLinearAllocBlock(LinearAllocBlock* blk) { |
duke@435 | 1875 | assert_locked(); |
duke@435 | 1876 | if (blk->_ptr != NULL) { |
duke@435 | 1877 | assert(blk->_word_size != 0 && blk->_word_size >= MinChunkSize, |
duke@435 | 1878 | "Minimum block size requirement"); |
duke@435 | 1879 | FreeChunk* fc = (FreeChunk*)(blk->_ptr); |
duke@435 | 1880 | fc->setSize(blk->_word_size); |
duke@435 | 1881 | fc->linkPrev(NULL); // mark as free |
duke@435 | 1882 | fc->dontCoalesce(); |
duke@435 | 1883 | assert(fc->isFree(), "just marked it free"); |
duke@435 | 1884 | assert(fc->cantCoalesce(), "just marked it uncoalescable"); |
duke@435 | 1885 | } |
duke@435 | 1886 | } |
duke@435 | 1887 | |
duke@435 | 1888 | void CompactibleFreeListSpace::refillLinearAllocBlocksIfNeeded() { |
duke@435 | 1889 | assert_locked(); |
duke@435 | 1890 | if (_smallLinearAllocBlock._ptr == NULL) { |
duke@435 | 1891 | assert(_smallLinearAllocBlock._word_size == 0, |
duke@435 | 1892 | "Size of linAB should be zero if the ptr is NULL"); |
duke@435 | 1893 | // Reset the linAB refill and allocation size limit. |
duke@435 | 1894 | _smallLinearAllocBlock.set(0, 0, 1024*SmallForLinearAlloc, SmallForLinearAlloc); |
duke@435 | 1895 | } |
duke@435 | 1896 | refillLinearAllocBlockIfNeeded(&_smallLinearAllocBlock); |
duke@435 | 1897 | } |
duke@435 | 1898 | |
duke@435 | 1899 | void |
duke@435 | 1900 | CompactibleFreeListSpace::refillLinearAllocBlockIfNeeded(LinearAllocBlock* blk) { |
duke@435 | 1901 | assert_locked(); |
duke@435 | 1902 | assert((blk->_ptr == NULL && blk->_word_size == 0) || |
duke@435 | 1903 | (blk->_ptr != NULL && blk->_word_size >= MinChunkSize), |
duke@435 | 1904 | "blk invariant"); |
duke@435 | 1905 | if (blk->_ptr == NULL) { |
duke@435 | 1906 | refillLinearAllocBlock(blk); |
duke@435 | 1907 | } |
duke@435 | 1908 | if (PrintMiscellaneous && Verbose) { |
duke@435 | 1909 | if (blk->_word_size == 0) { |
duke@435 | 1910 | warning("CompactibleFreeListSpace(prologue):: Linear allocation failure"); |
duke@435 | 1911 | } |
duke@435 | 1912 | } |
duke@435 | 1913 | } |
duke@435 | 1914 | |
duke@435 | 1915 | void |
duke@435 | 1916 | CompactibleFreeListSpace::refillLinearAllocBlock(LinearAllocBlock* blk) { |
duke@435 | 1917 | assert_locked(); |
duke@435 | 1918 | assert(blk->_word_size == 0 && blk->_ptr == NULL, |
duke@435 | 1919 | "linear allocation block should be empty"); |
duke@435 | 1920 | FreeChunk* fc; |
duke@435 | 1921 | if (blk->_refillSize < SmallForDictionary && |
duke@435 | 1922 | (fc = getChunkFromIndexedFreeList(blk->_refillSize)) != NULL) { |
duke@435 | 1923 | // A linAB's strategy might be to use small sizes to reduce |
duke@435 | 1924 | // fragmentation but still get the benefits of allocation from a |
duke@435 | 1925 | // linAB. |
duke@435 | 1926 | } else { |
duke@435 | 1927 | fc = getChunkFromDictionary(blk->_refillSize); |
duke@435 | 1928 | } |
duke@435 | 1929 | if (fc != NULL) { |
duke@435 | 1930 | blk->_ptr = (HeapWord*)fc; |
duke@435 | 1931 | blk->_word_size = fc->size(); |
duke@435 | 1932 | fc->dontCoalesce(); // to prevent sweeper from sweeping us up |
duke@435 | 1933 | } |
duke@435 | 1934 | } |
duke@435 | 1935 | |
ysr@447 | 1936 | // Support for concurrent collection policy decisions. |
ysr@447 | 1937 | bool CompactibleFreeListSpace::should_concurrent_collect() const { |
ysr@447 | 1938 | // In the future we might want to add in frgamentation stats -- |
ysr@447 | 1939 | // including erosion of the "mountain" into this decision as well. |
ysr@447 | 1940 | return !adaptive_freelists() && linearAllocationWouldFail(); |
ysr@447 | 1941 | } |
ysr@447 | 1942 | |
duke@435 | 1943 | // Support for compaction |
duke@435 | 1944 | |
duke@435 | 1945 | void CompactibleFreeListSpace::prepare_for_compaction(CompactPoint* cp) { |
duke@435 | 1946 | SCAN_AND_FORWARD(cp,end,block_is_obj,block_size); |
duke@435 | 1947 | // prepare_for_compaction() uses the space between live objects |
duke@435 | 1948 | // so that later phase can skip dead space quickly. So verification |
duke@435 | 1949 | // of the free lists doesn't work after. |
duke@435 | 1950 | } |
duke@435 | 1951 | |
duke@435 | 1952 | #define obj_size(q) adjustObjectSize(oop(q)->size()) |
duke@435 | 1953 | #define adjust_obj_size(s) adjustObjectSize(s) |
duke@435 | 1954 | |
duke@435 | 1955 | void CompactibleFreeListSpace::adjust_pointers() { |
duke@435 | 1956 | // In other versions of adjust_pointers(), a bail out |
duke@435 | 1957 | // based on the amount of live data in the generation |
duke@435 | 1958 | // (i.e., if 0, bail out) may be used. |
duke@435 | 1959 | // Cannot test used() == 0 here because the free lists have already |
duke@435 | 1960 | // been mangled by the compaction. |
duke@435 | 1961 | |
duke@435 | 1962 | SCAN_AND_ADJUST_POINTERS(adjust_obj_size); |
duke@435 | 1963 | // See note about verification in prepare_for_compaction(). |
duke@435 | 1964 | } |
duke@435 | 1965 | |
duke@435 | 1966 | void CompactibleFreeListSpace::compact() { |
duke@435 | 1967 | SCAN_AND_COMPACT(obj_size); |
duke@435 | 1968 | } |
duke@435 | 1969 | |
duke@435 | 1970 | // fragmentation_metric = 1 - [sum of (fbs**2) / (sum of fbs)**2] |
duke@435 | 1971 | // where fbs is free block sizes |
duke@435 | 1972 | double CompactibleFreeListSpace::flsFrag() const { |
duke@435 | 1973 | size_t itabFree = totalSizeInIndexedFreeLists(); |
duke@435 | 1974 | double frag = 0.0; |
duke@435 | 1975 | size_t i; |
duke@435 | 1976 | |
duke@435 | 1977 | for (i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 1978 | double sz = i; |
duke@435 | 1979 | frag += _indexedFreeList[i].count() * (sz * sz); |
duke@435 | 1980 | } |
duke@435 | 1981 | |
duke@435 | 1982 | double totFree = itabFree + |
duke@435 | 1983 | _dictionary->totalChunkSize(DEBUG_ONLY(freelistLock())); |
duke@435 | 1984 | if (totFree > 0) { |
duke@435 | 1985 | frag = ((frag + _dictionary->sum_of_squared_block_sizes()) / |
duke@435 | 1986 | (totFree * totFree)); |
duke@435 | 1987 | frag = (double)1.0 - frag; |
duke@435 | 1988 | } else { |
duke@435 | 1989 | assert(frag == 0.0, "Follows from totFree == 0"); |
duke@435 | 1990 | } |
duke@435 | 1991 | return frag; |
duke@435 | 1992 | } |
duke@435 | 1993 | |
duke@435 | 1994 | #define CoalSurplusPercent 1.05 |
duke@435 | 1995 | #define SplitSurplusPercent 1.10 |
duke@435 | 1996 | |
duke@435 | 1997 | void CompactibleFreeListSpace::beginSweepFLCensus( |
duke@435 | 1998 | float inter_sweep_current, |
duke@435 | 1999 | float inter_sweep_estimate) { |
duke@435 | 2000 | assert_locked(); |
duke@435 | 2001 | size_t i; |
duke@435 | 2002 | for (i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 2003 | FreeList* fl = &_indexedFreeList[i]; |
duke@435 | 2004 | fl->compute_desired(inter_sweep_current, inter_sweep_estimate); |
duke@435 | 2005 | fl->set_coalDesired((ssize_t)((double)fl->desired() * CoalSurplusPercent)); |
duke@435 | 2006 | fl->set_beforeSweep(fl->count()); |
duke@435 | 2007 | fl->set_bfrSurp(fl->surplus()); |
duke@435 | 2008 | } |
duke@435 | 2009 | _dictionary->beginSweepDictCensus(CoalSurplusPercent, |
duke@435 | 2010 | inter_sweep_current, |
duke@435 | 2011 | inter_sweep_estimate); |
duke@435 | 2012 | } |
duke@435 | 2013 | |
duke@435 | 2014 | void CompactibleFreeListSpace::setFLSurplus() { |
duke@435 | 2015 | assert_locked(); |
duke@435 | 2016 | size_t i; |
duke@435 | 2017 | for (i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 2018 | FreeList *fl = &_indexedFreeList[i]; |
duke@435 | 2019 | fl->set_surplus(fl->count() - |
duke@435 | 2020 | (ssize_t)((double)fl->desired() * SplitSurplusPercent)); |
duke@435 | 2021 | } |
duke@435 | 2022 | } |
duke@435 | 2023 | |
duke@435 | 2024 | void CompactibleFreeListSpace::setFLHints() { |
duke@435 | 2025 | assert_locked(); |
duke@435 | 2026 | size_t i; |
duke@435 | 2027 | size_t h = IndexSetSize; |
duke@435 | 2028 | for (i = IndexSetSize - 1; i != 0; i -= IndexSetStride) { |
duke@435 | 2029 | FreeList *fl = &_indexedFreeList[i]; |
duke@435 | 2030 | fl->set_hint(h); |
duke@435 | 2031 | if (fl->surplus() > 0) { |
duke@435 | 2032 | h = i; |
duke@435 | 2033 | } |
duke@435 | 2034 | } |
duke@435 | 2035 | } |
duke@435 | 2036 | |
duke@435 | 2037 | void CompactibleFreeListSpace::clearFLCensus() { |
duke@435 | 2038 | assert_locked(); |
duke@435 | 2039 | int i; |
duke@435 | 2040 | for (i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 2041 | FreeList *fl = &_indexedFreeList[i]; |
duke@435 | 2042 | fl->set_prevSweep(fl->count()); |
duke@435 | 2043 | fl->set_coalBirths(0); |
duke@435 | 2044 | fl->set_coalDeaths(0); |
duke@435 | 2045 | fl->set_splitBirths(0); |
duke@435 | 2046 | fl->set_splitDeaths(0); |
duke@435 | 2047 | } |
duke@435 | 2048 | } |
duke@435 | 2049 | |
ysr@447 | 2050 | void CompactibleFreeListSpace::endSweepFLCensus(size_t sweep_count) { |
duke@435 | 2051 | setFLSurplus(); |
duke@435 | 2052 | setFLHints(); |
duke@435 | 2053 | if (PrintGC && PrintFLSCensus > 0) { |
ysr@447 | 2054 | printFLCensus(sweep_count); |
duke@435 | 2055 | } |
duke@435 | 2056 | clearFLCensus(); |
duke@435 | 2057 | assert_locked(); |
duke@435 | 2058 | _dictionary->endSweepDictCensus(SplitSurplusPercent); |
duke@435 | 2059 | } |
duke@435 | 2060 | |
duke@435 | 2061 | bool CompactibleFreeListSpace::coalOverPopulated(size_t size) { |
duke@435 | 2062 | if (size < SmallForDictionary) { |
duke@435 | 2063 | FreeList *fl = &_indexedFreeList[size]; |
duke@435 | 2064 | return (fl->coalDesired() < 0) || |
duke@435 | 2065 | ((int)fl->count() > fl->coalDesired()); |
duke@435 | 2066 | } else { |
duke@435 | 2067 | return dictionary()->coalDictOverPopulated(size); |
duke@435 | 2068 | } |
duke@435 | 2069 | } |
duke@435 | 2070 | |
duke@435 | 2071 | void CompactibleFreeListSpace::smallCoalBirth(size_t size) { |
duke@435 | 2072 | assert(size < SmallForDictionary, "Size too large for indexed list"); |
duke@435 | 2073 | FreeList *fl = &_indexedFreeList[size]; |
duke@435 | 2074 | fl->increment_coalBirths(); |
duke@435 | 2075 | fl->increment_surplus(); |
duke@435 | 2076 | } |
duke@435 | 2077 | |
duke@435 | 2078 | void CompactibleFreeListSpace::smallCoalDeath(size_t size) { |
duke@435 | 2079 | assert(size < SmallForDictionary, "Size too large for indexed list"); |
duke@435 | 2080 | FreeList *fl = &_indexedFreeList[size]; |
duke@435 | 2081 | fl->increment_coalDeaths(); |
duke@435 | 2082 | fl->decrement_surplus(); |
duke@435 | 2083 | } |
duke@435 | 2084 | |
duke@435 | 2085 | void CompactibleFreeListSpace::coalBirth(size_t size) { |
duke@435 | 2086 | if (size < SmallForDictionary) { |
duke@435 | 2087 | smallCoalBirth(size); |
duke@435 | 2088 | } else { |
duke@435 | 2089 | dictionary()->dictCensusUpdate(size, |
duke@435 | 2090 | false /* split */, |
duke@435 | 2091 | true /* birth */); |
duke@435 | 2092 | } |
duke@435 | 2093 | } |
duke@435 | 2094 | |
duke@435 | 2095 | void CompactibleFreeListSpace::coalDeath(size_t size) { |
duke@435 | 2096 | if(size < SmallForDictionary) { |
duke@435 | 2097 | smallCoalDeath(size); |
duke@435 | 2098 | } else { |
duke@435 | 2099 | dictionary()->dictCensusUpdate(size, |
duke@435 | 2100 | false /* split */, |
duke@435 | 2101 | false /* birth */); |
duke@435 | 2102 | } |
duke@435 | 2103 | } |
duke@435 | 2104 | |
duke@435 | 2105 | void CompactibleFreeListSpace::smallSplitBirth(size_t size) { |
duke@435 | 2106 | assert(size < SmallForDictionary, "Size too large for indexed list"); |
duke@435 | 2107 | FreeList *fl = &_indexedFreeList[size]; |
duke@435 | 2108 | fl->increment_splitBirths(); |
duke@435 | 2109 | fl->increment_surplus(); |
duke@435 | 2110 | } |
duke@435 | 2111 | |
duke@435 | 2112 | void CompactibleFreeListSpace::smallSplitDeath(size_t size) { |
duke@435 | 2113 | assert(size < SmallForDictionary, "Size too large for indexed list"); |
duke@435 | 2114 | FreeList *fl = &_indexedFreeList[size]; |
duke@435 | 2115 | fl->increment_splitDeaths(); |
duke@435 | 2116 | fl->decrement_surplus(); |
duke@435 | 2117 | } |
duke@435 | 2118 | |
duke@435 | 2119 | void CompactibleFreeListSpace::splitBirth(size_t size) { |
duke@435 | 2120 | if (size < SmallForDictionary) { |
duke@435 | 2121 | smallSplitBirth(size); |
duke@435 | 2122 | } else { |
duke@435 | 2123 | dictionary()->dictCensusUpdate(size, |
duke@435 | 2124 | true /* split */, |
duke@435 | 2125 | true /* birth */); |
duke@435 | 2126 | } |
duke@435 | 2127 | } |
duke@435 | 2128 | |
duke@435 | 2129 | void CompactibleFreeListSpace::splitDeath(size_t size) { |
duke@435 | 2130 | if (size < SmallForDictionary) { |
duke@435 | 2131 | smallSplitDeath(size); |
duke@435 | 2132 | } else { |
duke@435 | 2133 | dictionary()->dictCensusUpdate(size, |
duke@435 | 2134 | true /* split */, |
duke@435 | 2135 | false /* birth */); |
duke@435 | 2136 | } |
duke@435 | 2137 | } |
duke@435 | 2138 | |
duke@435 | 2139 | void CompactibleFreeListSpace::split(size_t from, size_t to1) { |
duke@435 | 2140 | size_t to2 = from - to1; |
duke@435 | 2141 | splitDeath(from); |
duke@435 | 2142 | splitBirth(to1); |
duke@435 | 2143 | splitBirth(to2); |
duke@435 | 2144 | } |
duke@435 | 2145 | |
duke@435 | 2146 | void CompactibleFreeListSpace::print() const { |
duke@435 | 2147 | tty->print(" CompactibleFreeListSpace"); |
duke@435 | 2148 | Space::print(); |
duke@435 | 2149 | } |
duke@435 | 2150 | |
duke@435 | 2151 | void CompactibleFreeListSpace::prepare_for_verify() { |
duke@435 | 2152 | assert_locked(); |
duke@435 | 2153 | repairLinearAllocationBlocks(); |
duke@435 | 2154 | // Verify that the SpoolBlocks look like free blocks of |
duke@435 | 2155 | // appropriate sizes... To be done ... |
duke@435 | 2156 | } |
duke@435 | 2157 | |
duke@435 | 2158 | class VerifyAllBlksClosure: public BlkClosure { |
coleenp@548 | 2159 | private: |
duke@435 | 2160 | const CompactibleFreeListSpace* _sp; |
duke@435 | 2161 | const MemRegion _span; |
duke@435 | 2162 | |
duke@435 | 2163 | public: |
duke@435 | 2164 | VerifyAllBlksClosure(const CompactibleFreeListSpace* sp, |
duke@435 | 2165 | MemRegion span) : _sp(sp), _span(span) { } |
duke@435 | 2166 | |
coleenp@548 | 2167 | virtual size_t do_blk(HeapWord* addr) { |
duke@435 | 2168 | size_t res; |
duke@435 | 2169 | if (_sp->block_is_obj(addr)) { |
duke@435 | 2170 | oop p = oop(addr); |
duke@435 | 2171 | guarantee(p->is_oop(), "Should be an oop"); |
duke@435 | 2172 | res = _sp->adjustObjectSize(p->size()); |
duke@435 | 2173 | if (_sp->obj_is_alive(addr)) { |
duke@435 | 2174 | p->verify(); |
duke@435 | 2175 | } |
duke@435 | 2176 | } else { |
duke@435 | 2177 | FreeChunk* fc = (FreeChunk*)addr; |
duke@435 | 2178 | res = fc->size(); |
duke@435 | 2179 | if (FLSVerifyLists && !fc->cantCoalesce()) { |
duke@435 | 2180 | guarantee(_sp->verifyChunkInFreeLists(fc), |
duke@435 | 2181 | "Chunk should be on a free list"); |
duke@435 | 2182 | } |
duke@435 | 2183 | } |
duke@435 | 2184 | guarantee(res != 0, "Livelock: no rank reduction!"); |
duke@435 | 2185 | return res; |
duke@435 | 2186 | } |
duke@435 | 2187 | }; |
duke@435 | 2188 | |
duke@435 | 2189 | class VerifyAllOopsClosure: public OopClosure { |
coleenp@548 | 2190 | private: |
duke@435 | 2191 | const CMSCollector* _collector; |
duke@435 | 2192 | const CompactibleFreeListSpace* _sp; |
duke@435 | 2193 | const MemRegion _span; |
duke@435 | 2194 | const bool _past_remark; |
duke@435 | 2195 | const CMSBitMap* _bit_map; |
duke@435 | 2196 | |
coleenp@548 | 2197 | protected: |
coleenp@548 | 2198 | void do_oop(void* p, oop obj) { |
coleenp@548 | 2199 | if (_span.contains(obj)) { // the interior oop points into CMS heap |
coleenp@548 | 2200 | if (!_span.contains(p)) { // reference from outside CMS heap |
coleenp@548 | 2201 | // Should be a valid object; the first disjunct below allows |
coleenp@548 | 2202 | // us to sidestep an assertion in block_is_obj() that insists |
coleenp@548 | 2203 | // that p be in _sp. Note that several generations (and spaces) |
coleenp@548 | 2204 | // are spanned by _span (CMS heap) above. |
coleenp@548 | 2205 | guarantee(!_sp->is_in_reserved(obj) || |
coleenp@548 | 2206 | _sp->block_is_obj((HeapWord*)obj), |
coleenp@548 | 2207 | "Should be an object"); |
coleenp@548 | 2208 | guarantee(obj->is_oop(), "Should be an oop"); |
coleenp@548 | 2209 | obj->verify(); |
coleenp@548 | 2210 | if (_past_remark) { |
coleenp@548 | 2211 | // Remark has been completed, the object should be marked |
coleenp@548 | 2212 | _bit_map->isMarked((HeapWord*)obj); |
coleenp@548 | 2213 | } |
coleenp@548 | 2214 | } else { // reference within CMS heap |
coleenp@548 | 2215 | if (_past_remark) { |
coleenp@548 | 2216 | // Remark has been completed -- so the referent should have |
coleenp@548 | 2217 | // been marked, if referring object is. |
coleenp@548 | 2218 | if (_bit_map->isMarked(_collector->block_start(p))) { |
coleenp@548 | 2219 | guarantee(_bit_map->isMarked((HeapWord*)obj), "Marking error?"); |
coleenp@548 | 2220 | } |
coleenp@548 | 2221 | } |
coleenp@548 | 2222 | } |
coleenp@548 | 2223 | } else if (_sp->is_in_reserved(p)) { |
coleenp@548 | 2224 | // the reference is from FLS, and points out of FLS |
coleenp@548 | 2225 | guarantee(obj->is_oop(), "Should be an oop"); |
coleenp@548 | 2226 | obj->verify(); |
coleenp@548 | 2227 | } |
coleenp@548 | 2228 | } |
coleenp@548 | 2229 | |
coleenp@548 | 2230 | template <class T> void do_oop_work(T* p) { |
coleenp@548 | 2231 | T heap_oop = oopDesc::load_heap_oop(p); |
coleenp@548 | 2232 | if (!oopDesc::is_null(heap_oop)) { |
coleenp@548 | 2233 | oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); |
coleenp@548 | 2234 | do_oop(p, obj); |
coleenp@548 | 2235 | } |
coleenp@548 | 2236 | } |
coleenp@548 | 2237 | |
duke@435 | 2238 | public: |
duke@435 | 2239 | VerifyAllOopsClosure(const CMSCollector* collector, |
duke@435 | 2240 | const CompactibleFreeListSpace* sp, MemRegion span, |
duke@435 | 2241 | bool past_remark, CMSBitMap* bit_map) : |
duke@435 | 2242 | OopClosure(), _collector(collector), _sp(sp), _span(span), |
duke@435 | 2243 | _past_remark(past_remark), _bit_map(bit_map) { } |
duke@435 | 2244 | |
coleenp@548 | 2245 | virtual void do_oop(oop* p) { VerifyAllOopsClosure::do_oop_work(p); } |
coleenp@548 | 2246 | virtual void do_oop(narrowOop* p) { VerifyAllOopsClosure::do_oop_work(p); } |
duke@435 | 2247 | }; |
duke@435 | 2248 | |
duke@435 | 2249 | void CompactibleFreeListSpace::verify(bool ignored) const { |
duke@435 | 2250 | assert_lock_strong(&_freelistLock); |
duke@435 | 2251 | verify_objects_initialized(); |
duke@435 | 2252 | MemRegion span = _collector->_span; |
duke@435 | 2253 | bool past_remark = (_collector->abstract_state() == |
duke@435 | 2254 | CMSCollector::Sweeping); |
duke@435 | 2255 | |
duke@435 | 2256 | ResourceMark rm; |
duke@435 | 2257 | HandleMark hm; |
duke@435 | 2258 | |
duke@435 | 2259 | // Check integrity of CFL data structures |
duke@435 | 2260 | _promoInfo.verify(); |
duke@435 | 2261 | _dictionary->verify(); |
duke@435 | 2262 | if (FLSVerifyIndexTable) { |
duke@435 | 2263 | verifyIndexedFreeLists(); |
duke@435 | 2264 | } |
duke@435 | 2265 | // Check integrity of all objects and free blocks in space |
duke@435 | 2266 | { |
duke@435 | 2267 | VerifyAllBlksClosure cl(this, span); |
duke@435 | 2268 | ((CompactibleFreeListSpace*)this)->blk_iterate(&cl); // cast off const |
duke@435 | 2269 | } |
duke@435 | 2270 | // Check that all references in the heap to FLS |
duke@435 | 2271 | // are to valid objects in FLS or that references in |
duke@435 | 2272 | // FLS are to valid objects elsewhere in the heap |
duke@435 | 2273 | if (FLSVerifyAllHeapReferences) |
duke@435 | 2274 | { |
duke@435 | 2275 | VerifyAllOopsClosure cl(_collector, this, span, past_remark, |
duke@435 | 2276 | _collector->markBitMap()); |
duke@435 | 2277 | CollectedHeap* ch = Universe::heap(); |
duke@435 | 2278 | ch->oop_iterate(&cl); // all oops in generations |
duke@435 | 2279 | ch->permanent_oop_iterate(&cl); // all oops in perm gen |
duke@435 | 2280 | } |
duke@435 | 2281 | |
duke@435 | 2282 | if (VerifyObjectStartArray) { |
duke@435 | 2283 | // Verify the block offset table |
duke@435 | 2284 | _bt.verify(); |
duke@435 | 2285 | } |
duke@435 | 2286 | } |
duke@435 | 2287 | |
duke@435 | 2288 | #ifndef PRODUCT |
duke@435 | 2289 | void CompactibleFreeListSpace::verifyFreeLists() const { |
duke@435 | 2290 | if (FLSVerifyLists) { |
duke@435 | 2291 | _dictionary->verify(); |
duke@435 | 2292 | verifyIndexedFreeLists(); |
duke@435 | 2293 | } else { |
duke@435 | 2294 | if (FLSVerifyDictionary) { |
duke@435 | 2295 | _dictionary->verify(); |
duke@435 | 2296 | } |
duke@435 | 2297 | if (FLSVerifyIndexTable) { |
duke@435 | 2298 | verifyIndexedFreeLists(); |
duke@435 | 2299 | } |
duke@435 | 2300 | } |
duke@435 | 2301 | } |
duke@435 | 2302 | #endif |
duke@435 | 2303 | |
duke@435 | 2304 | void CompactibleFreeListSpace::verifyIndexedFreeLists() const { |
duke@435 | 2305 | size_t i = 0; |
duke@435 | 2306 | for (; i < MinChunkSize; i++) { |
duke@435 | 2307 | guarantee(_indexedFreeList[i].head() == NULL, "should be NULL"); |
duke@435 | 2308 | } |
duke@435 | 2309 | for (; i < IndexSetSize; i++) { |
duke@435 | 2310 | verifyIndexedFreeList(i); |
duke@435 | 2311 | } |
duke@435 | 2312 | } |
duke@435 | 2313 | |
duke@435 | 2314 | void CompactibleFreeListSpace::verifyIndexedFreeList(size_t size) const { |
ysr@777 | 2315 | FreeChunk* fc = _indexedFreeList[size].head(); |
ysr@777 | 2316 | guarantee((size % 2 == 0) || fc == NULL, "Odd slots should be empty"); |
ysr@777 | 2317 | for (; fc != NULL; fc = fc->next()) { |
duke@435 | 2318 | guarantee(fc->size() == size, "Size inconsistency"); |
duke@435 | 2319 | guarantee(fc->isFree(), "!free?"); |
duke@435 | 2320 | guarantee(fc->next() == NULL || fc->next()->prev() == fc, "Broken list"); |
duke@435 | 2321 | } |
duke@435 | 2322 | } |
duke@435 | 2323 | |
duke@435 | 2324 | #ifndef PRODUCT |
duke@435 | 2325 | void CompactibleFreeListSpace::checkFreeListConsistency() const { |
duke@435 | 2326 | assert(_dictionary->minSize() <= IndexSetSize, |
duke@435 | 2327 | "Some sizes can't be allocated without recourse to" |
duke@435 | 2328 | " linear allocation buffers"); |
duke@435 | 2329 | assert(MIN_TREE_CHUNK_SIZE*HeapWordSize == sizeof(TreeChunk), |
duke@435 | 2330 | "else MIN_TREE_CHUNK_SIZE is wrong"); |
duke@435 | 2331 | assert((IndexSetStride == 2 && IndexSetStart == 2) || |
duke@435 | 2332 | (IndexSetStride == 1 && IndexSetStart == 1), "just checking"); |
duke@435 | 2333 | assert((IndexSetStride != 2) || (MinChunkSize % 2 == 0), |
duke@435 | 2334 | "Some for-loops may be incorrectly initialized"); |
duke@435 | 2335 | assert((IndexSetStride != 2) || (IndexSetSize % 2 == 1), |
duke@435 | 2336 | "For-loops that iterate over IndexSet with stride 2 may be wrong"); |
duke@435 | 2337 | } |
duke@435 | 2338 | #endif |
duke@435 | 2339 | |
ysr@447 | 2340 | void CompactibleFreeListSpace::printFLCensus(size_t sweep_count) const { |
duke@435 | 2341 | assert_lock_strong(&_freelistLock); |
ysr@447 | 2342 | FreeList total; |
ysr@447 | 2343 | gclog_or_tty->print("end sweep# " SIZE_FORMAT "\n", sweep_count); |
ysr@447 | 2344 | FreeList::print_labels_on(gclog_or_tty, "size"); |
duke@435 | 2345 | size_t totalFree = 0; |
duke@435 | 2346 | for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
duke@435 | 2347 | const FreeList *fl = &_indexedFreeList[i]; |
ysr@447 | 2348 | totalFree += fl->count() * fl->size(); |
ysr@447 | 2349 | if (i % (40*IndexSetStride) == 0) { |
ysr@447 | 2350 | FreeList::print_labels_on(gclog_or_tty, "size"); |
ysr@447 | 2351 | } |
ysr@447 | 2352 | fl->print_on(gclog_or_tty); |
ysr@447 | 2353 | total.set_bfrSurp( total.bfrSurp() + fl->bfrSurp() ); |
ysr@447 | 2354 | total.set_surplus( total.surplus() + fl->surplus() ); |
ysr@447 | 2355 | total.set_desired( total.desired() + fl->desired() ); |
ysr@447 | 2356 | total.set_prevSweep( total.prevSweep() + fl->prevSweep() ); |
ysr@447 | 2357 | total.set_beforeSweep(total.beforeSweep() + fl->beforeSweep()); |
ysr@447 | 2358 | total.set_count( total.count() + fl->count() ); |
ysr@447 | 2359 | total.set_coalBirths( total.coalBirths() + fl->coalBirths() ); |
ysr@447 | 2360 | total.set_coalDeaths( total.coalDeaths() + fl->coalDeaths() ); |
ysr@447 | 2361 | total.set_splitBirths(total.splitBirths() + fl->splitBirths()); |
ysr@447 | 2362 | total.set_splitDeaths(total.splitDeaths() + fl->splitDeaths()); |
duke@435 | 2363 | } |
ysr@447 | 2364 | total.print_on(gclog_or_tty, "TOTAL"); |
ysr@447 | 2365 | gclog_or_tty->print_cr("Total free in indexed lists " |
ysr@447 | 2366 | SIZE_FORMAT " words", totalFree); |
duke@435 | 2367 | gclog_or_tty->print("growth: %8.5f deficit: %8.5f\n", |
ysr@447 | 2368 | (double)(total.splitBirths()+total.coalBirths()-total.splitDeaths()-total.coalDeaths())/ |
ysr@447 | 2369 | (total.prevSweep() != 0 ? (double)total.prevSweep() : 1.0), |
ysr@447 | 2370 | (double)(total.desired() - total.count())/(total.desired() != 0 ? (double)total.desired() : 1.0)); |
duke@435 | 2371 | _dictionary->printDictCensus(); |
duke@435 | 2372 | } |
duke@435 | 2373 | |
duke@435 | 2374 | // Return the next displaced header, incrementing the pointer and |
duke@435 | 2375 | // recycling spool area as necessary. |
duke@435 | 2376 | markOop PromotionInfo::nextDisplacedHeader() { |
duke@435 | 2377 | assert(_spoolHead != NULL, "promotionInfo inconsistency"); |
duke@435 | 2378 | assert(_spoolHead != _spoolTail || _firstIndex < _nextIndex, |
duke@435 | 2379 | "Empty spool space: no displaced header can be fetched"); |
duke@435 | 2380 | assert(_spoolHead->bufferSize > _firstIndex, "Off by one error at head?"); |
duke@435 | 2381 | markOop hdr = _spoolHead->displacedHdr[_firstIndex]; |
duke@435 | 2382 | // Spool forward |
duke@435 | 2383 | if (++_firstIndex == _spoolHead->bufferSize) { // last location in this block |
duke@435 | 2384 | // forward to next block, recycling this block into spare spool buffer |
duke@435 | 2385 | SpoolBlock* tmp = _spoolHead->nextSpoolBlock; |
duke@435 | 2386 | assert(_spoolHead != _spoolTail, "Spooling storage mix-up"); |
duke@435 | 2387 | _spoolHead->nextSpoolBlock = _spareSpool; |
duke@435 | 2388 | _spareSpool = _spoolHead; |
duke@435 | 2389 | _spoolHead = tmp; |
duke@435 | 2390 | _firstIndex = 1; |
duke@435 | 2391 | NOT_PRODUCT( |
duke@435 | 2392 | if (_spoolHead == NULL) { // all buffers fully consumed |
duke@435 | 2393 | assert(_spoolTail == NULL && _nextIndex == 1, |
duke@435 | 2394 | "spool buffers processing inconsistency"); |
duke@435 | 2395 | } |
duke@435 | 2396 | ) |
duke@435 | 2397 | } |
duke@435 | 2398 | return hdr; |
duke@435 | 2399 | } |
duke@435 | 2400 | |
duke@435 | 2401 | void PromotionInfo::track(PromotedObject* trackOop) { |
duke@435 | 2402 | track(trackOop, oop(trackOop)->klass()); |
duke@435 | 2403 | } |
duke@435 | 2404 | |
duke@435 | 2405 | void PromotionInfo::track(PromotedObject* trackOop, klassOop klassOfOop) { |
duke@435 | 2406 | // make a copy of header as it may need to be spooled |
duke@435 | 2407 | markOop mark = oop(trackOop)->mark(); |
duke@435 | 2408 | trackOop->clearNext(); |
duke@435 | 2409 | if (mark->must_be_preserved_for_cms_scavenge(klassOfOop)) { |
duke@435 | 2410 | // save non-prototypical header, and mark oop |
duke@435 | 2411 | saveDisplacedHeader(mark); |
duke@435 | 2412 | trackOop->setDisplacedMark(); |
duke@435 | 2413 | } else { |
duke@435 | 2414 | // we'd like to assert something like the following: |
duke@435 | 2415 | // assert(mark == markOopDesc::prototype(), "consistency check"); |
duke@435 | 2416 | // ... but the above won't work because the age bits have not (yet) been |
duke@435 | 2417 | // cleared. The remainder of the check would be identical to the |
duke@435 | 2418 | // condition checked in must_be_preserved() above, so we don't really |
duke@435 | 2419 | // have anything useful to check here! |
duke@435 | 2420 | } |
duke@435 | 2421 | if (_promoTail != NULL) { |
duke@435 | 2422 | assert(_promoHead != NULL, "List consistency"); |
duke@435 | 2423 | _promoTail->setNext(trackOop); |
duke@435 | 2424 | _promoTail = trackOop; |
duke@435 | 2425 | } else { |
duke@435 | 2426 | assert(_promoHead == NULL, "List consistency"); |
duke@435 | 2427 | _promoHead = _promoTail = trackOop; |
duke@435 | 2428 | } |
duke@435 | 2429 | // Mask as newly promoted, so we can skip over such objects |
duke@435 | 2430 | // when scanning dirty cards |
duke@435 | 2431 | assert(!trackOop->hasPromotedMark(), "Should not have been marked"); |
duke@435 | 2432 | trackOop->setPromotedMark(); |
duke@435 | 2433 | } |
duke@435 | 2434 | |
duke@435 | 2435 | // Save the given displaced header, incrementing the pointer and |
duke@435 | 2436 | // obtaining more spool area as necessary. |
duke@435 | 2437 | void PromotionInfo::saveDisplacedHeader(markOop hdr) { |
duke@435 | 2438 | assert(_spoolHead != NULL && _spoolTail != NULL, |
duke@435 | 2439 | "promotionInfo inconsistency"); |
duke@435 | 2440 | assert(_spoolTail->bufferSize > _nextIndex, "Off by one error at tail?"); |
duke@435 | 2441 | _spoolTail->displacedHdr[_nextIndex] = hdr; |
duke@435 | 2442 | // Spool forward |
duke@435 | 2443 | if (++_nextIndex == _spoolTail->bufferSize) { // last location in this block |
duke@435 | 2444 | // get a new spooling block |
duke@435 | 2445 | assert(_spoolTail->nextSpoolBlock == NULL, "tail should terminate spool list"); |
duke@435 | 2446 | _splice_point = _spoolTail; // save for splicing |
duke@435 | 2447 | _spoolTail->nextSpoolBlock = getSpoolBlock(); // might fail |
duke@435 | 2448 | _spoolTail = _spoolTail->nextSpoolBlock; // might become NULL ... |
duke@435 | 2449 | // ... but will attempt filling before next promotion attempt |
duke@435 | 2450 | _nextIndex = 1; |
duke@435 | 2451 | } |
duke@435 | 2452 | } |
duke@435 | 2453 | |
duke@435 | 2454 | // Ensure that spooling space exists. Return false if spooling space |
duke@435 | 2455 | // could not be obtained. |
duke@435 | 2456 | bool PromotionInfo::ensure_spooling_space_work() { |
duke@435 | 2457 | assert(!has_spooling_space(), "Only call when there is no spooling space"); |
duke@435 | 2458 | // Try and obtain more spooling space |
duke@435 | 2459 | SpoolBlock* newSpool = getSpoolBlock(); |
duke@435 | 2460 | assert(newSpool == NULL || |
duke@435 | 2461 | (newSpool->bufferSize != 0 && newSpool->nextSpoolBlock == NULL), |
duke@435 | 2462 | "getSpoolBlock() sanity check"); |
duke@435 | 2463 | if (newSpool == NULL) { |
duke@435 | 2464 | return false; |
duke@435 | 2465 | } |
duke@435 | 2466 | _nextIndex = 1; |
duke@435 | 2467 | if (_spoolTail == NULL) { |
duke@435 | 2468 | _spoolTail = newSpool; |
duke@435 | 2469 | if (_spoolHead == NULL) { |
duke@435 | 2470 | _spoolHead = newSpool; |
duke@435 | 2471 | _firstIndex = 1; |
duke@435 | 2472 | } else { |
duke@435 | 2473 | assert(_splice_point != NULL && _splice_point->nextSpoolBlock == NULL, |
duke@435 | 2474 | "Splice point invariant"); |
duke@435 | 2475 | // Extra check that _splice_point is connected to list |
duke@435 | 2476 | #ifdef ASSERT |
duke@435 | 2477 | { |
duke@435 | 2478 | SpoolBlock* blk = _spoolHead; |
duke@435 | 2479 | for (; blk->nextSpoolBlock != NULL; |
duke@435 | 2480 | blk = blk->nextSpoolBlock); |
duke@435 | 2481 | assert(blk != NULL && blk == _splice_point, |
duke@435 | 2482 | "Splice point incorrect"); |
duke@435 | 2483 | } |
duke@435 | 2484 | #endif // ASSERT |
duke@435 | 2485 | _splice_point->nextSpoolBlock = newSpool; |
duke@435 | 2486 | } |
duke@435 | 2487 | } else { |
duke@435 | 2488 | assert(_spoolHead != NULL, "spool list consistency"); |
duke@435 | 2489 | _spoolTail->nextSpoolBlock = newSpool; |
duke@435 | 2490 | _spoolTail = newSpool; |
duke@435 | 2491 | } |
duke@435 | 2492 | return true; |
duke@435 | 2493 | } |
duke@435 | 2494 | |
duke@435 | 2495 | // Get a free spool buffer from the free pool, getting a new block |
duke@435 | 2496 | // from the heap if necessary. |
duke@435 | 2497 | SpoolBlock* PromotionInfo::getSpoolBlock() { |
duke@435 | 2498 | SpoolBlock* res; |
duke@435 | 2499 | if ((res = _spareSpool) != NULL) { |
duke@435 | 2500 | _spareSpool = _spareSpool->nextSpoolBlock; |
duke@435 | 2501 | res->nextSpoolBlock = NULL; |
duke@435 | 2502 | } else { // spare spool exhausted, get some from heap |
duke@435 | 2503 | res = (SpoolBlock*)(space()->allocateScratch(refillSize())); |
duke@435 | 2504 | if (res != NULL) { |
duke@435 | 2505 | res->init(); |
duke@435 | 2506 | } |
duke@435 | 2507 | } |
duke@435 | 2508 | assert(res == NULL || res->nextSpoolBlock == NULL, "postcondition"); |
duke@435 | 2509 | return res; |
duke@435 | 2510 | } |
duke@435 | 2511 | |
duke@435 | 2512 | void PromotionInfo::startTrackingPromotions() { |
duke@435 | 2513 | assert(_spoolHead == _spoolTail && _firstIndex == _nextIndex, |
duke@435 | 2514 | "spooling inconsistency?"); |
duke@435 | 2515 | _firstIndex = _nextIndex = 1; |
duke@435 | 2516 | _tracking = true; |
duke@435 | 2517 | } |
duke@435 | 2518 | |
duke@435 | 2519 | void PromotionInfo::stopTrackingPromotions() { |
duke@435 | 2520 | assert(_spoolHead == _spoolTail && _firstIndex == _nextIndex, |
duke@435 | 2521 | "spooling inconsistency?"); |
duke@435 | 2522 | _firstIndex = _nextIndex = 1; |
duke@435 | 2523 | _tracking = false; |
duke@435 | 2524 | } |
duke@435 | 2525 | |
duke@435 | 2526 | // When _spoolTail is not NULL, then the slot <_spoolTail, _nextIndex> |
duke@435 | 2527 | // points to the next slot available for filling. |
duke@435 | 2528 | // The set of slots holding displaced headers are then all those in the |
duke@435 | 2529 | // right-open interval denoted by: |
duke@435 | 2530 | // |
duke@435 | 2531 | // [ <_spoolHead, _firstIndex>, <_spoolTail, _nextIndex> ) |
duke@435 | 2532 | // |
duke@435 | 2533 | // When _spoolTail is NULL, then the set of slots with displaced headers |
duke@435 | 2534 | // is all those starting at the slot <_spoolHead, _firstIndex> and |
duke@435 | 2535 | // going up to the last slot of last block in the linked list. |
duke@435 | 2536 | // In this lartter case, _splice_point points to the tail block of |
duke@435 | 2537 | // this linked list of blocks holding displaced headers. |
duke@435 | 2538 | void PromotionInfo::verify() const { |
duke@435 | 2539 | // Verify the following: |
duke@435 | 2540 | // 1. the number of displaced headers matches the number of promoted |
duke@435 | 2541 | // objects that have displaced headers |
duke@435 | 2542 | // 2. each promoted object lies in this space |
duke@435 | 2543 | debug_only( |
duke@435 | 2544 | PromotedObject* junk = NULL; |
duke@435 | 2545 | assert(junk->next_addr() == (void*)(oop(junk)->mark_addr()), |
duke@435 | 2546 | "Offset of PromotedObject::_next is expected to align with " |
duke@435 | 2547 | " the OopDesc::_mark within OopDesc"); |
duke@435 | 2548 | ) |
duke@435 | 2549 | // FIXME: guarantee???? |
duke@435 | 2550 | guarantee(_spoolHead == NULL || _spoolTail != NULL || |
duke@435 | 2551 | _splice_point != NULL, "list consistency"); |
duke@435 | 2552 | guarantee(_promoHead == NULL || _promoTail != NULL, "list consistency"); |
duke@435 | 2553 | // count the number of objects with displaced headers |
duke@435 | 2554 | size_t numObjsWithDisplacedHdrs = 0; |
duke@435 | 2555 | for (PromotedObject* curObj = _promoHead; curObj != NULL; curObj = curObj->next()) { |
duke@435 | 2556 | guarantee(space()->is_in_reserved((HeapWord*)curObj), "Containment"); |
duke@435 | 2557 | // the last promoted object may fail the mark() != NULL test of is_oop(). |
duke@435 | 2558 | guarantee(curObj->next() == NULL || oop(curObj)->is_oop(), "must be an oop"); |
duke@435 | 2559 | if (curObj->hasDisplacedMark()) { |
duke@435 | 2560 | numObjsWithDisplacedHdrs++; |
duke@435 | 2561 | } |
duke@435 | 2562 | } |
duke@435 | 2563 | // Count the number of displaced headers |
duke@435 | 2564 | size_t numDisplacedHdrs = 0; |
duke@435 | 2565 | for (SpoolBlock* curSpool = _spoolHead; |
duke@435 | 2566 | curSpool != _spoolTail && curSpool != NULL; |
duke@435 | 2567 | curSpool = curSpool->nextSpoolBlock) { |
duke@435 | 2568 | // the first entry is just a self-pointer; indices 1 through |
duke@435 | 2569 | // bufferSize - 1 are occupied (thus, bufferSize - 1 slots). |
duke@435 | 2570 | guarantee((void*)curSpool->displacedHdr == (void*)&curSpool->displacedHdr, |
duke@435 | 2571 | "first entry of displacedHdr should be self-referential"); |
duke@435 | 2572 | numDisplacedHdrs += curSpool->bufferSize - 1; |
duke@435 | 2573 | } |
duke@435 | 2574 | guarantee((_spoolHead == _spoolTail) == (numDisplacedHdrs == 0), |
duke@435 | 2575 | "internal consistency"); |
duke@435 | 2576 | guarantee(_spoolTail != NULL || _nextIndex == 1, |
duke@435 | 2577 | "Inconsistency between _spoolTail and _nextIndex"); |
duke@435 | 2578 | // We overcounted (_firstIndex-1) worth of slots in block |
duke@435 | 2579 | // _spoolHead and we undercounted (_nextIndex-1) worth of |
duke@435 | 2580 | // slots in block _spoolTail. We make an appropriate |
duke@435 | 2581 | // adjustment by subtracting the first and adding the |
duke@435 | 2582 | // second: - (_firstIndex - 1) + (_nextIndex - 1) |
duke@435 | 2583 | numDisplacedHdrs += (_nextIndex - _firstIndex); |
duke@435 | 2584 | guarantee(numDisplacedHdrs == numObjsWithDisplacedHdrs, "Displaced hdr count"); |
duke@435 | 2585 | } |
duke@435 | 2586 | |
duke@435 | 2587 | |
duke@435 | 2588 | CFLS_LAB::CFLS_LAB(CompactibleFreeListSpace* cfls) : |
duke@435 | 2589 | _cfls(cfls) |
duke@435 | 2590 | { |
duke@435 | 2591 | _blocks_to_claim = CMSParPromoteBlocksToClaim; |
duke@435 | 2592 | for (size_t i = CompactibleFreeListSpace::IndexSetStart; |
duke@435 | 2593 | i < CompactibleFreeListSpace::IndexSetSize; |
duke@435 | 2594 | i += CompactibleFreeListSpace::IndexSetStride) { |
duke@435 | 2595 | _indexedFreeList[i].set_size(i); |
duke@435 | 2596 | } |
duke@435 | 2597 | } |
duke@435 | 2598 | |
duke@435 | 2599 | HeapWord* CFLS_LAB::alloc(size_t word_sz) { |
duke@435 | 2600 | FreeChunk* res; |
duke@435 | 2601 | word_sz = _cfls->adjustObjectSize(word_sz); |
duke@435 | 2602 | if (word_sz >= CompactibleFreeListSpace::IndexSetSize) { |
duke@435 | 2603 | // This locking manages sync with other large object allocations. |
duke@435 | 2604 | MutexLockerEx x(_cfls->parDictionaryAllocLock(), |
duke@435 | 2605 | Mutex::_no_safepoint_check_flag); |
duke@435 | 2606 | res = _cfls->getChunkFromDictionaryExact(word_sz); |
duke@435 | 2607 | if (res == NULL) return NULL; |
duke@435 | 2608 | } else { |
duke@435 | 2609 | FreeList* fl = &_indexedFreeList[word_sz]; |
duke@435 | 2610 | bool filled = false; //TRAP |
duke@435 | 2611 | if (fl->count() == 0) { |
duke@435 | 2612 | bool filled = true; //TRAP |
duke@435 | 2613 | // Attempt to refill this local free list. |
duke@435 | 2614 | _cfls->par_get_chunk_of_blocks(word_sz, _blocks_to_claim, fl); |
duke@435 | 2615 | // If it didn't work, give up. |
duke@435 | 2616 | if (fl->count() == 0) return NULL; |
duke@435 | 2617 | } |
duke@435 | 2618 | res = fl->getChunkAtHead(); |
duke@435 | 2619 | assert(res != NULL, "Why was count non-zero?"); |
duke@435 | 2620 | } |
duke@435 | 2621 | res->markNotFree(); |
duke@435 | 2622 | assert(!res->isFree(), "shouldn't be marked free"); |
coleenp@622 | 2623 | assert(oop(res)->klass_or_null() == NULL, "should look uninitialized"); |
duke@435 | 2624 | // mangle a just allocated object with a distinct pattern. |
duke@435 | 2625 | debug_only(res->mangleAllocated(word_sz)); |
duke@435 | 2626 | return (HeapWord*)res; |
duke@435 | 2627 | } |
duke@435 | 2628 | |
duke@435 | 2629 | void CFLS_LAB::retire() { |
duke@435 | 2630 | for (size_t i = CompactibleFreeListSpace::IndexSetStart; |
duke@435 | 2631 | i < CompactibleFreeListSpace::IndexSetSize; |
duke@435 | 2632 | i += CompactibleFreeListSpace::IndexSetStride) { |
duke@435 | 2633 | if (_indexedFreeList[i].count() > 0) { |
duke@435 | 2634 | MutexLockerEx x(_cfls->_indexedFreeListParLocks[i], |
duke@435 | 2635 | Mutex::_no_safepoint_check_flag); |
duke@435 | 2636 | _cfls->_indexedFreeList[i].prepend(&_indexedFreeList[i]); |
duke@435 | 2637 | // Reset this list. |
duke@435 | 2638 | _indexedFreeList[i] = FreeList(); |
duke@435 | 2639 | _indexedFreeList[i].set_size(i); |
duke@435 | 2640 | } |
duke@435 | 2641 | } |
duke@435 | 2642 | } |
duke@435 | 2643 | |
duke@435 | 2644 | void |
duke@435 | 2645 | CompactibleFreeListSpace:: |
duke@435 | 2646 | par_get_chunk_of_blocks(size_t word_sz, size_t n, FreeList* fl) { |
duke@435 | 2647 | assert(fl->count() == 0, "Precondition."); |
duke@435 | 2648 | assert(word_sz < CompactibleFreeListSpace::IndexSetSize, |
duke@435 | 2649 | "Precondition"); |
duke@435 | 2650 | |
duke@435 | 2651 | // We'll try all multiples of word_sz in the indexed set (starting with |
duke@435 | 2652 | // word_sz itself), then try getting a big chunk and splitting it. |
duke@435 | 2653 | int k = 1; |
duke@435 | 2654 | size_t cur_sz = k * word_sz; |
duke@435 | 2655 | bool found = false; |
duke@435 | 2656 | while (cur_sz < CompactibleFreeListSpace::IndexSetSize && k == 1) { |
duke@435 | 2657 | FreeList* gfl = &_indexedFreeList[cur_sz]; |
duke@435 | 2658 | FreeList fl_for_cur_sz; // Empty. |
duke@435 | 2659 | fl_for_cur_sz.set_size(cur_sz); |
duke@435 | 2660 | { |
duke@435 | 2661 | MutexLockerEx x(_indexedFreeListParLocks[cur_sz], |
duke@435 | 2662 | Mutex::_no_safepoint_check_flag); |
duke@435 | 2663 | if (gfl->count() != 0) { |
duke@435 | 2664 | size_t nn = MAX2(n/k, (size_t)1); |
duke@435 | 2665 | gfl->getFirstNChunksFromList(nn, &fl_for_cur_sz); |
duke@435 | 2666 | found = true; |
duke@435 | 2667 | } |
duke@435 | 2668 | } |
duke@435 | 2669 | // Now transfer fl_for_cur_sz to fl. Common case, we hope, is k = 1. |
duke@435 | 2670 | if (found) { |
duke@435 | 2671 | if (k == 1) { |
duke@435 | 2672 | fl->prepend(&fl_for_cur_sz); |
duke@435 | 2673 | } else { |
duke@435 | 2674 | // Divide each block on fl_for_cur_sz up k ways. |
duke@435 | 2675 | FreeChunk* fc; |
duke@435 | 2676 | while ((fc = fl_for_cur_sz.getChunkAtHead()) != NULL) { |
duke@435 | 2677 | // Must do this in reverse order, so that anybody attempting to |
duke@435 | 2678 | // access the main chunk sees it as a single free block until we |
duke@435 | 2679 | // change it. |
duke@435 | 2680 | size_t fc_size = fc->size(); |
duke@435 | 2681 | for (int i = k-1; i >= 0; i--) { |
duke@435 | 2682 | FreeChunk* ffc = (FreeChunk*)((HeapWord*)fc + i * word_sz); |
duke@435 | 2683 | ffc->setSize(word_sz); |
duke@435 | 2684 | ffc->linkNext(NULL); |
duke@435 | 2685 | ffc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. |
duke@435 | 2686 | // Above must occur before BOT is updated below. |
duke@435 | 2687 | // splitting from the right, fc_size == (k - i + 1) * wordsize |
duke@435 | 2688 | _bt.mark_block((HeapWord*)ffc, word_sz); |
duke@435 | 2689 | fc_size -= word_sz; |
duke@435 | 2690 | _bt.verify_not_unallocated((HeapWord*)ffc, ffc->size()); |
duke@435 | 2691 | _bt.verify_single_block((HeapWord*)fc, fc_size); |
duke@435 | 2692 | _bt.verify_single_block((HeapWord*)ffc, ffc->size()); |
duke@435 | 2693 | // Push this on "fl". |
duke@435 | 2694 | fl->returnChunkAtHead(ffc); |
duke@435 | 2695 | } |
duke@435 | 2696 | // TRAP |
duke@435 | 2697 | assert(fl->tail()->next() == NULL, "List invariant."); |
duke@435 | 2698 | } |
duke@435 | 2699 | } |
duke@435 | 2700 | return; |
duke@435 | 2701 | } |
duke@435 | 2702 | k++; cur_sz = k * word_sz; |
duke@435 | 2703 | } |
duke@435 | 2704 | // Otherwise, we'll split a block from the dictionary. |
duke@435 | 2705 | FreeChunk* fc = NULL; |
duke@435 | 2706 | FreeChunk* rem_fc = NULL; |
duke@435 | 2707 | size_t rem; |
duke@435 | 2708 | { |
duke@435 | 2709 | MutexLockerEx x(parDictionaryAllocLock(), |
duke@435 | 2710 | Mutex::_no_safepoint_check_flag); |
duke@435 | 2711 | while (n > 0) { |
duke@435 | 2712 | fc = dictionary()->getChunk(MAX2(n * word_sz, |
duke@435 | 2713 | _dictionary->minSize()), |
duke@435 | 2714 | FreeBlockDictionary::atLeast); |
duke@435 | 2715 | if (fc != NULL) { |
duke@435 | 2716 | _bt.allocated((HeapWord*)fc, fc->size()); // update _unallocated_blk |
duke@435 | 2717 | dictionary()->dictCensusUpdate(fc->size(), |
duke@435 | 2718 | true /*split*/, |
duke@435 | 2719 | false /*birth*/); |
duke@435 | 2720 | break; |
duke@435 | 2721 | } else { |
duke@435 | 2722 | n--; |
duke@435 | 2723 | } |
duke@435 | 2724 | } |
duke@435 | 2725 | if (fc == NULL) return; |
duke@435 | 2726 | // Otherwise, split up that block. |
duke@435 | 2727 | size_t nn = fc->size() / word_sz; |
duke@435 | 2728 | n = MIN2(nn, n); |
duke@435 | 2729 | rem = fc->size() - n * word_sz; |
duke@435 | 2730 | // If there is a remainder, and it's too small, allocate one fewer. |
duke@435 | 2731 | if (rem > 0 && rem < MinChunkSize) { |
duke@435 | 2732 | n--; rem += word_sz; |
duke@435 | 2733 | } |
duke@435 | 2734 | // First return the remainder, if any. |
duke@435 | 2735 | // Note that we hold the lock until we decide if we're going to give |
duke@435 | 2736 | // back the remainder to the dictionary, since a contending allocator |
duke@435 | 2737 | // may otherwise see the heap as empty. (We're willing to take that |
duke@435 | 2738 | // hit if the block is a small block.) |
duke@435 | 2739 | if (rem > 0) { |
duke@435 | 2740 | size_t prefix_size = n * word_sz; |
duke@435 | 2741 | rem_fc = (FreeChunk*)((HeapWord*)fc + prefix_size); |
duke@435 | 2742 | rem_fc->setSize(rem); |
duke@435 | 2743 | rem_fc->linkNext(NULL); |
duke@435 | 2744 | rem_fc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. |
duke@435 | 2745 | // Above must occur before BOT is updated below. |
duke@435 | 2746 | _bt.split_block((HeapWord*)fc, fc->size(), prefix_size); |
duke@435 | 2747 | if (rem >= IndexSetSize) { |
duke@435 | 2748 | returnChunkToDictionary(rem_fc); |
duke@435 | 2749 | dictionary()->dictCensusUpdate(fc->size(), |
duke@435 | 2750 | true /*split*/, |
duke@435 | 2751 | true /*birth*/); |
duke@435 | 2752 | rem_fc = NULL; |
duke@435 | 2753 | } |
duke@435 | 2754 | // Otherwise, return it to the small list below. |
duke@435 | 2755 | } |
duke@435 | 2756 | } |
duke@435 | 2757 | // |
duke@435 | 2758 | if (rem_fc != NULL) { |
duke@435 | 2759 | MutexLockerEx x(_indexedFreeListParLocks[rem], |
duke@435 | 2760 | Mutex::_no_safepoint_check_flag); |
duke@435 | 2761 | _bt.verify_not_unallocated((HeapWord*)rem_fc, rem_fc->size()); |
duke@435 | 2762 | _indexedFreeList[rem].returnChunkAtHead(rem_fc); |
duke@435 | 2763 | smallSplitBirth(rem); |
duke@435 | 2764 | } |
duke@435 | 2765 | |
duke@435 | 2766 | // Now do the splitting up. |
duke@435 | 2767 | // Must do this in reverse order, so that anybody attempting to |
duke@435 | 2768 | // access the main chunk sees it as a single free block until we |
duke@435 | 2769 | // change it. |
duke@435 | 2770 | size_t fc_size = n * word_sz; |
duke@435 | 2771 | // All but first chunk in this loop |
duke@435 | 2772 | for (ssize_t i = n-1; i > 0; i--) { |
duke@435 | 2773 | FreeChunk* ffc = (FreeChunk*)((HeapWord*)fc + i * word_sz); |
duke@435 | 2774 | ffc->setSize(word_sz); |
duke@435 | 2775 | ffc->linkNext(NULL); |
duke@435 | 2776 | ffc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. |
duke@435 | 2777 | // Above must occur before BOT is updated below. |
duke@435 | 2778 | // splitting from the right, fc_size == (n - i + 1) * wordsize |
duke@435 | 2779 | _bt.mark_block((HeapWord*)ffc, word_sz); |
duke@435 | 2780 | fc_size -= word_sz; |
duke@435 | 2781 | _bt.verify_not_unallocated((HeapWord*)ffc, ffc->size()); |
duke@435 | 2782 | _bt.verify_single_block((HeapWord*)ffc, ffc->size()); |
duke@435 | 2783 | _bt.verify_single_block((HeapWord*)fc, fc_size); |
duke@435 | 2784 | // Push this on "fl". |
duke@435 | 2785 | fl->returnChunkAtHead(ffc); |
duke@435 | 2786 | } |
duke@435 | 2787 | // First chunk |
duke@435 | 2788 | fc->setSize(word_sz); |
duke@435 | 2789 | fc->linkNext(NULL); |
duke@435 | 2790 | fc->linkPrev(NULL); |
duke@435 | 2791 | _bt.verify_not_unallocated((HeapWord*)fc, fc->size()); |
duke@435 | 2792 | _bt.verify_single_block((HeapWord*)fc, fc->size()); |
duke@435 | 2793 | fl->returnChunkAtHead(fc); |
duke@435 | 2794 | |
duke@435 | 2795 | { |
duke@435 | 2796 | MutexLockerEx x(_indexedFreeListParLocks[word_sz], |
duke@435 | 2797 | Mutex::_no_safepoint_check_flag); |
duke@435 | 2798 | ssize_t new_births = _indexedFreeList[word_sz].splitBirths() + n; |
duke@435 | 2799 | _indexedFreeList[word_sz].set_splitBirths(new_births); |
duke@435 | 2800 | ssize_t new_surplus = _indexedFreeList[word_sz].surplus() + n; |
duke@435 | 2801 | _indexedFreeList[word_sz].set_surplus(new_surplus); |
duke@435 | 2802 | } |
duke@435 | 2803 | |
duke@435 | 2804 | // TRAP |
duke@435 | 2805 | assert(fl->tail()->next() == NULL, "List invariant."); |
duke@435 | 2806 | } |
duke@435 | 2807 | |
duke@435 | 2808 | // Set up the space's par_seq_tasks structure for work claiming |
duke@435 | 2809 | // for parallel rescan. See CMSParRemarkTask where this is currently used. |
duke@435 | 2810 | // XXX Need to suitably abstract and generalize this and the next |
duke@435 | 2811 | // method into one. |
duke@435 | 2812 | void |
duke@435 | 2813 | CompactibleFreeListSpace:: |
duke@435 | 2814 | initialize_sequential_subtasks_for_rescan(int n_threads) { |
duke@435 | 2815 | // The "size" of each task is fixed according to rescan_task_size. |
duke@435 | 2816 | assert(n_threads > 0, "Unexpected n_threads argument"); |
duke@435 | 2817 | const size_t task_size = rescan_task_size(); |
duke@435 | 2818 | size_t n_tasks = (used_region().word_size() + task_size - 1)/task_size; |
ysr@775 | 2819 | assert((n_tasks == 0) == used_region().is_empty(), "n_tasks incorrect"); |
ysr@775 | 2820 | assert(n_tasks == 0 || |
ysr@775 | 2821 | ((used_region().start() + (n_tasks - 1)*task_size < used_region().end()) && |
ysr@775 | 2822 | (used_region().start() + n_tasks*task_size >= used_region().end())), |
ysr@775 | 2823 | "n_tasks calculation incorrect"); |
duke@435 | 2824 | SequentialSubTasksDone* pst = conc_par_seq_tasks(); |
duke@435 | 2825 | assert(!pst->valid(), "Clobbering existing data?"); |
duke@435 | 2826 | pst->set_par_threads(n_threads); |
duke@435 | 2827 | pst->set_n_tasks((int)n_tasks); |
duke@435 | 2828 | } |
duke@435 | 2829 | |
duke@435 | 2830 | // Set up the space's par_seq_tasks structure for work claiming |
duke@435 | 2831 | // for parallel concurrent marking. See CMSConcMarkTask where this is currently used. |
duke@435 | 2832 | void |
duke@435 | 2833 | CompactibleFreeListSpace:: |
duke@435 | 2834 | initialize_sequential_subtasks_for_marking(int n_threads, |
duke@435 | 2835 | HeapWord* low) { |
duke@435 | 2836 | // The "size" of each task is fixed according to rescan_task_size. |
duke@435 | 2837 | assert(n_threads > 0, "Unexpected n_threads argument"); |
duke@435 | 2838 | const size_t task_size = marking_task_size(); |
duke@435 | 2839 | assert(task_size > CardTableModRefBS::card_size_in_words && |
duke@435 | 2840 | (task_size % CardTableModRefBS::card_size_in_words == 0), |
duke@435 | 2841 | "Otherwise arithmetic below would be incorrect"); |
duke@435 | 2842 | MemRegion span = _gen->reserved(); |
duke@435 | 2843 | if (low != NULL) { |
duke@435 | 2844 | if (span.contains(low)) { |
duke@435 | 2845 | // Align low down to a card boundary so that |
duke@435 | 2846 | // we can use block_offset_careful() on span boundaries. |
duke@435 | 2847 | HeapWord* aligned_low = (HeapWord*)align_size_down((uintptr_t)low, |
duke@435 | 2848 | CardTableModRefBS::card_size); |
duke@435 | 2849 | // Clip span prefix at aligned_low |
duke@435 | 2850 | span = span.intersection(MemRegion(aligned_low, span.end())); |
duke@435 | 2851 | } else if (low > span.end()) { |
duke@435 | 2852 | span = MemRegion(low, low); // Null region |
duke@435 | 2853 | } // else use entire span |
duke@435 | 2854 | } |
duke@435 | 2855 | assert(span.is_empty() || |
duke@435 | 2856 | ((uintptr_t)span.start() % CardTableModRefBS::card_size == 0), |
duke@435 | 2857 | "span should start at a card boundary"); |
duke@435 | 2858 | size_t n_tasks = (span.word_size() + task_size - 1)/task_size; |
duke@435 | 2859 | assert((n_tasks == 0) == span.is_empty(), "Inconsistency"); |
duke@435 | 2860 | assert(n_tasks == 0 || |
duke@435 | 2861 | ((span.start() + (n_tasks - 1)*task_size < span.end()) && |
duke@435 | 2862 | (span.start() + n_tasks*task_size >= span.end())), |
ysr@775 | 2863 | "n_tasks calculation incorrect"); |
duke@435 | 2864 | SequentialSubTasksDone* pst = conc_par_seq_tasks(); |
duke@435 | 2865 | assert(!pst->valid(), "Clobbering existing data?"); |
duke@435 | 2866 | pst->set_par_threads(n_threads); |
duke@435 | 2867 | pst->set_n_tasks((int)n_tasks); |
duke@435 | 2868 | } |