christian.plesner.hansen | 43d26ec | 2008-07-03 15:10:15 +0000 | [diff] [blame^] | 1 | // Copyright 2006-2008 Google Inc. All Rights Reserved. |
| 2 | // Redistribution and use in source and binary forms, with or without |
| 3 | // modification, are permitted provided that the following conditions are |
| 4 | // met: |
| 5 | // |
| 6 | // * Redistributions of source code must retain the above copyright |
| 7 | // notice, this list of conditions and the following disclaimer. |
| 8 | // * Redistributions in binary form must reproduce the above |
| 9 | // copyright notice, this list of conditions and the following |
| 10 | // disclaimer in the documentation and/or other materials provided |
| 11 | // with the distribution. |
| 12 | // * Neither the name of Google Inc. nor the names of its |
| 13 | // contributors may be used to endorse or promote products derived |
| 14 | // from this software without specific prior written permission. |
| 15 | // |
| 16 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 17 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 18 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 19 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 20 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 21 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 22 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 23 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 24 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 25 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 26 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 27 | |
| 28 | #include "v8.h" |
| 29 | |
| 30 | #include "accessors.h" |
| 31 | #include "api.h" |
| 32 | #include "bootstrapper.h" |
| 33 | #include "codegen-inl.h" |
| 34 | #include "debug.h" |
| 35 | #include "global-handles.h" |
| 36 | #include "jsregexp.h" |
| 37 | #include "mark-compact.h" |
| 38 | #include "natives.h" |
| 39 | #include "scanner.h" |
| 40 | #include "scopeinfo.h" |
| 41 | #include "v8threads.h" |
| 42 | |
| 43 | namespace v8 { namespace internal { |
| 44 | |
| 45 | #ifdef DEBUG |
| 46 | DEFINE_bool(gc_greedy, false, "perform GC prior to some allocations"); |
| 47 | DEFINE_bool(gc_verbose, false, "print stuff during garbage collection"); |
| 48 | DEFINE_bool(heap_stats, false, "report heap statistics before and after GC"); |
| 49 | DEFINE_bool(code_stats, false, "report code statistics after GC"); |
| 50 | DEFINE_bool(verify_heap, false, "verify heap pointers before and after GC"); |
| 51 | DEFINE_bool(print_handles, false, "report handles after GC"); |
| 52 | DEFINE_bool(print_global_handles, false, "report global handles after GC"); |
| 53 | DEFINE_bool(print_rset, false, "print remembered sets before GC"); |
| 54 | #endif |
| 55 | |
| 56 | DEFINE_int(new_space_size, 0, "size of (each semispace in) the new generation"); |
| 57 | DEFINE_int(old_space_size, 0, "size of the old generation"); |
| 58 | |
| 59 | DEFINE_bool(gc_global, false, "always perform global GCs"); |
| 60 | DEFINE_int(gc_interval, -1, "garbage collect after <n> allocations"); |
| 61 | DEFINE_bool(trace_gc, false, |
| 62 | "print one trace line following each garbage collection"); |
| 63 | |
| 64 | |
| 65 | #ifdef ENABLE_LOGGING_AND_PROFILING |
| 66 | DECLARE_bool(log_gc); |
| 67 | #endif |
| 68 | |
| 69 | |
| 70 | #define ROOT_ALLOCATION(type, name) type* Heap::name##_; |
| 71 | ROOT_LIST(ROOT_ALLOCATION) |
| 72 | #undef ROOT_ALLOCATION |
| 73 | |
| 74 | |
| 75 | #define STRUCT_ALLOCATION(NAME, Name, name) Map* Heap::name##_map_; |
| 76 | STRUCT_LIST(STRUCT_ALLOCATION) |
| 77 | #undef STRUCT_ALLOCATION |
| 78 | |
| 79 | |
| 80 | #define SYMBOL_ALLOCATION(name, string) String* Heap::name##_; |
| 81 | SYMBOL_LIST(SYMBOL_ALLOCATION) |
| 82 | #undef SYMBOL_ALLOCATION |
| 83 | |
| 84 | |
| 85 | NewSpace* Heap::new_space_ = NULL; |
| 86 | OldSpace* Heap::old_space_ = NULL; |
| 87 | OldSpace* Heap::code_space_ = NULL; |
| 88 | MapSpace* Heap::map_space_ = NULL; |
| 89 | LargeObjectSpace* Heap::lo_space_ = NULL; |
| 90 | |
| 91 | int Heap::promoted_space_limit_ = 0; |
| 92 | int Heap::old_gen_exhausted_ = false; |
| 93 | |
| 94 | // semispace_size_ should be a power of 2 and old_generation_size_ should be |
| 95 | // a multiple of Page::kPageSize. |
| 96 | int Heap::semispace_size_ = 1*MB; |
| 97 | int Heap::old_generation_size_ = 512*MB; |
| 98 | int Heap::initial_semispace_size_ = 256*KB; |
| 99 | |
| 100 | GCCallback Heap::global_gc_prologue_callback_ = NULL; |
| 101 | GCCallback Heap::global_gc_epilogue_callback_ = NULL; |
| 102 | |
| 103 | // Variables set based on semispace_size_ and old_generation_size_ in |
| 104 | // ConfigureHeap. |
| 105 | int Heap::young_generation_size_ = 0; // Will be 2 * semispace_size_. |
| 106 | |
| 107 | // Double the new space after this many scavenge collections. |
| 108 | int Heap::new_space_growth_limit_ = 8; |
| 109 | int Heap::scavenge_count_ = 0; |
| 110 | Heap::HeapState Heap::gc_state_ = NOT_IN_GC; |
| 111 | |
| 112 | #ifdef DEBUG |
| 113 | bool Heap::allocation_allowed_ = true; |
| 114 | int Heap::mc_count_ = 0; |
| 115 | int Heap::gc_count_ = 0; |
| 116 | |
| 117 | int Heap::allocation_timeout_ = 0; |
| 118 | bool Heap::disallow_allocation_failure_ = false; |
| 119 | #endif // DEBUG |
| 120 | |
| 121 | |
| 122 | int Heap::Capacity() { |
| 123 | if (!HasBeenSetup()) return 0; |
| 124 | |
| 125 | return new_space_->Capacity() + |
| 126 | old_space_->Capacity() + |
| 127 | code_space_->Capacity() + |
| 128 | map_space_->Capacity(); |
| 129 | } |
| 130 | |
| 131 | |
| 132 | int Heap::Available() { |
| 133 | if (!HasBeenSetup()) return 0; |
| 134 | |
| 135 | return new_space_->Available() + |
| 136 | old_space_->Available() + |
| 137 | code_space_->Available() + |
| 138 | map_space_->Available(); |
| 139 | } |
| 140 | |
| 141 | |
| 142 | bool Heap::HasBeenSetup() { |
| 143 | return new_space_ != NULL && |
| 144 | old_space_ != NULL && |
| 145 | code_space_ != NULL && |
| 146 | map_space_ != NULL && |
| 147 | lo_space_ != NULL; |
| 148 | } |
| 149 | |
| 150 | |
| 151 | GarbageCollector Heap::SelectGarbageCollector(AllocationSpace space) { |
| 152 | // Is global GC requested? |
| 153 | if (space != NEW_SPACE || FLAG_gc_global) { |
| 154 | Counters::gc_compactor_caused_by_request.Increment(); |
| 155 | return MARK_COMPACTOR; |
| 156 | } |
| 157 | |
| 158 | // Is enough data promoted to justify a global GC? |
| 159 | if (PromotedSpaceSize() > promoted_space_limit_) { |
| 160 | Counters::gc_compactor_caused_by_promoted_data.Increment(); |
| 161 | return MARK_COMPACTOR; |
| 162 | } |
| 163 | |
| 164 | // Have allocation in OLD and LO failed? |
| 165 | if (old_gen_exhausted_) { |
| 166 | Counters::gc_compactor_caused_by_oldspace_exhaustion.Increment(); |
| 167 | return MARK_COMPACTOR; |
| 168 | } |
| 169 | |
| 170 | // Is there enough space left in OLD to guarantee that a scavenge can |
| 171 | // succeed? |
| 172 | // |
| 173 | // Note that old_space_->MaxAvailable() undercounts the memory available |
| 174 | // for object promotion. It counts only the bytes that the memory |
| 175 | // allocator has not yet allocated from the OS and assigned to any space, |
| 176 | // and does not count available bytes already in the old space or code |
| 177 | // space. Undercounting is safe---we may get an unrequested full GC when |
| 178 | // a scavenge would have succeeded. |
| 179 | if (old_space_->MaxAvailable() <= new_space_->Size()) { |
| 180 | Counters::gc_compactor_caused_by_oldspace_exhaustion.Increment(); |
| 181 | return MARK_COMPACTOR; |
| 182 | } |
| 183 | |
| 184 | // Default |
| 185 | return SCAVENGER; |
| 186 | } |
| 187 | |
| 188 | |
| 189 | // TODO(1238405): Combine the infrastructure for --heap-stats and |
| 190 | // --log-gc to avoid the complicated preprocessor and flag testing. |
| 191 | #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| 192 | void Heap::ReportStatisticsBeforeGC() { |
| 193 | // Heap::ReportHeapStatistics will also log NewSpace statistics when |
| 194 | // compiled with ENABLE_LOGGING_AND_PROFILING and --log-gc is set. The |
| 195 | // following logic is used to avoid double logging. |
| 196 | #if defined(DEBUG) && defined(ENABLE_LOGGING_AND_PROFILING) |
| 197 | if (FLAG_heap_stats || FLAG_log_gc) new_space_->CollectStatistics(); |
| 198 | if (FLAG_heap_stats) { |
| 199 | ReportHeapStatistics("Before GC"); |
| 200 | } else if (FLAG_log_gc) { |
| 201 | new_space_->ReportStatistics(); |
| 202 | } |
| 203 | if (FLAG_heap_stats || FLAG_log_gc) new_space_->ClearHistograms(); |
| 204 | #elif defined(DEBUG) |
| 205 | if (FLAG_heap_stats) { |
| 206 | new_space_->CollectStatistics(); |
| 207 | ReportHeapStatistics("Before GC"); |
| 208 | new_space_->ClearHistograms(); |
| 209 | } |
| 210 | #elif defined(ENABLE_LOGGING_AND_PROFILING) |
| 211 | if (FLAG_log_gc) { |
| 212 | new_space_->CollectStatistics(); |
| 213 | new_space_->ReportStatistics(); |
| 214 | new_space_->ClearHistograms(); |
| 215 | } |
| 216 | #endif |
| 217 | } |
| 218 | |
| 219 | |
| 220 | // TODO(1238405): Combine the infrastructure for --heap-stats and |
| 221 | // --log-gc to avoid the complicated preprocessor and flag testing. |
| 222 | void Heap::ReportStatisticsAfterGC() { |
| 223 | // Similar to the before GC, we use some complicated logic to ensure that |
| 224 | // NewSpace statistics are logged exactly once when --log-gc is turned on. |
| 225 | #if defined(DEBUG) && defined(ENABLE_LOGGING_AND_PROFILING) |
| 226 | if (FLAG_heap_stats) { |
| 227 | ReportHeapStatistics("After GC"); |
| 228 | } else if (FLAG_log_gc) { |
| 229 | new_space_->ReportStatistics(); |
| 230 | } |
| 231 | #elif defined(DEBUG) |
| 232 | if (FLAG_heap_stats) ReportHeapStatistics("After GC"); |
| 233 | #elif defined(ENABLE_LOGGING_AND_PROFILING) |
| 234 | if (FLAG_log_gc) new_space_->ReportStatistics(); |
| 235 | #endif |
| 236 | } |
| 237 | #endif // defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| 238 | |
| 239 | |
| 240 | void Heap::GarbageCollectionPrologue() { |
| 241 | RegExpImpl::NewSpaceCollectionPrologue(); |
| 242 | #ifdef DEBUG |
| 243 | ASSERT(allocation_allowed_ && gc_state_ == NOT_IN_GC); |
| 244 | allow_allocation(false); |
| 245 | gc_count_++; |
| 246 | |
| 247 | if (FLAG_verify_heap) { |
| 248 | Verify(); |
| 249 | } |
| 250 | |
| 251 | if (FLAG_gc_verbose) Print(); |
| 252 | |
| 253 | if (FLAG_print_rset) { |
| 254 | // By definition, code space does not have remembered set bits that we |
| 255 | // care about. |
| 256 | old_space_->PrintRSet(); |
| 257 | map_space_->PrintRSet(); |
| 258 | lo_space_->PrintRSet(); |
| 259 | } |
| 260 | #endif |
| 261 | |
| 262 | #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| 263 | ReportStatisticsBeforeGC(); |
| 264 | #endif |
| 265 | } |
| 266 | |
| 267 | int Heap::SizeOfObjects() { |
| 268 | return new_space_->Size() + |
| 269 | old_space_->Size() + |
| 270 | code_space_->Size() + |
| 271 | map_space_->Size() + |
| 272 | lo_space_->Size(); |
| 273 | } |
| 274 | |
| 275 | void Heap::GarbageCollectionEpilogue() { |
| 276 | #ifdef DEBUG |
| 277 | allow_allocation(true); |
| 278 | ZapFromSpace(); |
| 279 | |
| 280 | if (FLAG_verify_heap) { |
| 281 | Verify(); |
| 282 | } |
| 283 | |
| 284 | if (FLAG_print_global_handles) GlobalHandles::Print(); |
| 285 | if (FLAG_print_handles) PrintHandles(); |
| 286 | if (FLAG_gc_verbose) Print(); |
| 287 | if (FLAG_code_stats) ReportCodeStatistics("After GC"); |
| 288 | #endif |
| 289 | |
| 290 | Counters::alive_after_last_gc.Set(SizeOfObjects()); |
| 291 | |
| 292 | SymbolTable* symbol_table = SymbolTable::cast(Heap::symbol_table_); |
| 293 | Counters::symbol_table_capacity.Set(symbol_table->Capacity()); |
| 294 | Counters::number_of_symbols.Set(symbol_table->NumberOfElements()); |
| 295 | #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| 296 | ReportStatisticsAfterGC(); |
| 297 | #endif |
| 298 | } |
| 299 | |
| 300 | |
| 301 | // GCTracer collects and prints ONE line after each garbage collector |
| 302 | // invocation IFF --trace_gc is used. |
| 303 | |
| 304 | class GCTracer BASE_EMBEDDED { |
| 305 | public: |
| 306 | GCTracer() : start_time_(0.0), start_size_(0.0) { |
| 307 | if (!FLAG_trace_gc) return; |
| 308 | start_time_ = OS::TimeCurrentMillis(); |
| 309 | start_size_ = SizeOfHeapObjects(); |
| 310 | } |
| 311 | |
| 312 | ~GCTracer() { |
| 313 | if (!FLAG_trace_gc) return; |
| 314 | // Printf ONE line iff flag is set. |
| 315 | PrintF("%s %.1f -> %.1f MB, %d ms.\n", |
| 316 | CollectorString(), |
| 317 | start_size_, SizeOfHeapObjects(), |
| 318 | static_cast<int>(OS::TimeCurrentMillis() - start_time_)); |
| 319 | } |
| 320 | |
| 321 | // Sets the collector. |
| 322 | void set_collector(GarbageCollector collector) { |
| 323 | collector_ = collector; |
| 324 | } |
| 325 | |
| 326 | private: |
| 327 | |
| 328 | // Returns a string matching the collector. |
| 329 | const char* CollectorString() { |
| 330 | switch (collector_) { |
| 331 | case SCAVENGER: |
| 332 | return "Scavenge"; |
| 333 | case MARK_COMPACTOR: |
| 334 | return MarkCompactCollector::HasCompacted() ? "Mark-compact" |
| 335 | : "Mark-sweep"; |
| 336 | } |
| 337 | return "Unknown GC"; |
| 338 | } |
| 339 | |
| 340 | // Returns size of object in heap (in MB). |
| 341 | double SizeOfHeapObjects() { |
| 342 | return (static_cast<double>(Heap::SizeOfObjects())) / MB; |
| 343 | } |
| 344 | |
| 345 | double start_time_; // Timestamp set in the constructor. |
| 346 | double start_size_; // Size of objects in heap set in constructor. |
| 347 | GarbageCollector collector_; // Type of collector. |
| 348 | }; |
| 349 | |
| 350 | |
| 351 | |
| 352 | bool Heap::CollectGarbage(int requested_size, AllocationSpace space) { |
| 353 | // The VM is in the GC state until exiting this function. |
| 354 | VMState state(GC); |
| 355 | |
| 356 | #ifdef DEBUG |
| 357 | // Reset the allocation timeout to the GC interval, but make sure to |
| 358 | // allow at least a few allocations after a collection. The reason |
| 359 | // for this is that we have a lot of allocation sequences and we |
| 360 | // assume that a garbage collection will allow the subsequent |
| 361 | // allocation attempts to go through. |
| 362 | allocation_timeout_ = Max(6, FLAG_gc_interval); |
| 363 | #endif |
| 364 | |
| 365 | { GCTracer tracer; |
| 366 | GarbageCollectionPrologue(); |
| 367 | |
| 368 | GarbageCollector collector = SelectGarbageCollector(space); |
| 369 | tracer.set_collector(collector); |
| 370 | |
| 371 | StatsRate* rate = (collector == SCAVENGER) |
| 372 | ? &Counters::gc_scavenger |
| 373 | : &Counters::gc_compactor; |
| 374 | rate->Start(); |
| 375 | PerformGarbageCollection(space, collector); |
| 376 | rate->Stop(); |
| 377 | |
| 378 | GarbageCollectionEpilogue(); |
| 379 | } |
| 380 | |
| 381 | |
| 382 | #ifdef ENABLE_LOGGING_AND_PROFILING |
| 383 | if (FLAG_log_gc) HeapProfiler::WriteSample(); |
| 384 | #endif |
| 385 | |
| 386 | switch (space) { |
| 387 | case NEW_SPACE: |
| 388 | return new_space_->Available() >= requested_size; |
| 389 | case OLD_SPACE: |
| 390 | return old_space_->Available() >= requested_size; |
| 391 | case CODE_SPACE: |
| 392 | return code_space_->Available() >= requested_size; |
| 393 | case MAP_SPACE: |
| 394 | return map_space_->Available() >= requested_size; |
| 395 | case LO_SPACE: |
| 396 | return lo_space_->Available() >= requested_size; |
| 397 | } |
| 398 | return false; |
| 399 | } |
| 400 | |
| 401 | |
| 402 | void Heap::PerformGarbageCollection(AllocationSpace space, |
| 403 | GarbageCollector collector) { |
| 404 | if (collector == MARK_COMPACTOR && global_gc_prologue_callback_) { |
| 405 | ASSERT(!allocation_allowed_); |
| 406 | global_gc_prologue_callback_(); |
| 407 | } |
| 408 | |
| 409 | if (collector == MARK_COMPACTOR) { |
| 410 | MarkCompact(); |
| 411 | |
| 412 | int promoted_space_size = PromotedSpaceSize(); |
| 413 | promoted_space_limit_ = |
| 414 | promoted_space_size + Max(2 * MB, (promoted_space_size/100) * 35); |
| 415 | old_gen_exhausted_ = false; |
| 416 | |
| 417 | // If we have used the mark-compact collector to collect the new |
| 418 | // space, and it has not compacted the new space, we force a |
| 419 | // separate scavenge collection. THIS IS A HACK. It covers the |
| 420 | // case where (1) a new space collection was requested, (2) the |
| 421 | // collector selection policy selected the mark-compact collector, |
| 422 | // and (3) the mark-compact collector policy selected not to |
| 423 | // compact the new space. In that case, there is no more (usable) |
| 424 | // free space in the new space after the collection compared to |
| 425 | // before. |
| 426 | if (space == NEW_SPACE && !MarkCompactCollector::HasCompacted()) { |
| 427 | Scavenge(); |
| 428 | } |
| 429 | } else { |
| 430 | Scavenge(); |
| 431 | } |
| 432 | Counters::objs_since_last_young.Set(0); |
| 433 | |
| 434 | // Process weak handles post gc. |
| 435 | GlobalHandles::PostGarbageCollectionProcessing(); |
| 436 | |
| 437 | if (collector == MARK_COMPACTOR && global_gc_epilogue_callback_) { |
| 438 | ASSERT(!allocation_allowed_); |
| 439 | global_gc_epilogue_callback_(); |
| 440 | } |
| 441 | } |
| 442 | |
| 443 | |
| 444 | void Heap::MarkCompact() { |
| 445 | gc_state_ = MARK_COMPACT; |
| 446 | #ifdef DEBUG |
| 447 | mc_count_++; |
| 448 | #endif |
| 449 | LOG(ResourceEvent("markcompact", "begin")); |
| 450 | |
| 451 | MarkCompactPrologue(); |
| 452 | |
| 453 | MarkCompactCollector::CollectGarbage(); |
| 454 | |
| 455 | MarkCompactEpilogue(); |
| 456 | |
| 457 | LOG(ResourceEvent("markcompact", "end")); |
| 458 | |
| 459 | gc_state_ = NOT_IN_GC; |
| 460 | |
| 461 | Shrink(); |
| 462 | |
| 463 | Counters::objs_since_last_full.Set(0); |
| 464 | } |
| 465 | |
| 466 | |
| 467 | void Heap::MarkCompactPrologue() { |
| 468 | RegExpImpl::OldSpaceCollectionPrologue(); |
| 469 | Top::MarkCompactPrologue(); |
| 470 | ThreadManager::MarkCompactPrologue(); |
| 471 | } |
| 472 | |
| 473 | |
| 474 | void Heap::MarkCompactEpilogue() { |
| 475 | Top::MarkCompactEpilogue(); |
| 476 | ThreadManager::MarkCompactEpilogue(); |
| 477 | } |
| 478 | |
| 479 | |
| 480 | Object* Heap::FindCodeObject(Address a) { |
| 481 | Object* obj = code_space_->FindObject(a); |
| 482 | if (obj->IsFailure()) { |
| 483 | obj = lo_space_->FindObject(a); |
| 484 | } |
| 485 | return obj; |
| 486 | } |
| 487 | |
| 488 | |
| 489 | // Helper class for copying HeapObjects |
| 490 | class CopyVisitor: public ObjectVisitor { |
| 491 | public: |
| 492 | |
| 493 | void VisitPointer(Object** p) { |
| 494 | CopyObject(p); |
| 495 | } |
| 496 | |
| 497 | void VisitPointers(Object** start, Object** end) { |
| 498 | // Copy all HeapObject pointers in [start, end) |
| 499 | for (Object** p = start; p < end; p++) CopyObject(p); |
| 500 | } |
| 501 | |
| 502 | private: |
| 503 | void CopyObject(Object** p) { |
| 504 | if (!Heap::InFromSpace(*p)) return; |
| 505 | Heap::CopyObject(reinterpret_cast<HeapObject**>(p)); |
| 506 | } |
| 507 | }; |
| 508 | |
| 509 | |
| 510 | // Shared state read by the scavenge collector and set by CopyObject. |
| 511 | static Address promoted_top = NULL; |
| 512 | |
| 513 | |
| 514 | #ifdef DEBUG |
| 515 | // Visitor class to verify pointers in code space do not point into |
| 516 | // new space. |
| 517 | class VerifyCodeSpacePointersVisitor: public ObjectVisitor { |
| 518 | public: |
| 519 | void VisitPointers(Object** start, Object**end) { |
| 520 | for (Object** current = start; current < end; current++) { |
| 521 | if ((*current)->IsHeapObject()) { |
| 522 | ASSERT(!Heap::InNewSpace(HeapObject::cast(*current))); |
| 523 | } |
| 524 | } |
| 525 | } |
| 526 | }; |
| 527 | #endif |
| 528 | |
| 529 | void Heap::Scavenge() { |
| 530 | #ifdef DEBUG |
| 531 | if (FLAG_enable_slow_asserts) { |
| 532 | VerifyCodeSpacePointersVisitor v; |
| 533 | HeapObjectIterator it(code_space_); |
| 534 | while (it.has_next()) { |
| 535 | HeapObject* object = it.next(); |
| 536 | if (object->IsCode()) { |
| 537 | Code::cast(object)->ConvertICTargetsFromAddressToObject(); |
| 538 | } |
| 539 | object->Iterate(&v); |
| 540 | if (object->IsCode()) { |
| 541 | Code::cast(object)->ConvertICTargetsFromObjectToAddress(); |
| 542 | } |
| 543 | } |
| 544 | } |
| 545 | #endif |
| 546 | |
| 547 | gc_state_ = SCAVENGE; |
| 548 | |
| 549 | // Implements Cheney's copying algorithm |
| 550 | LOG(ResourceEvent("scavenge", "begin")); |
| 551 | |
| 552 | scavenge_count_++; |
| 553 | if (new_space_->Capacity() < new_space_->MaximumCapacity() && |
| 554 | scavenge_count_ > new_space_growth_limit_) { |
| 555 | // Double the size of the new space, and double the limit. The next |
| 556 | // doubling attempt will occur after the current new_space_growth_limit_ |
| 557 | // more collections. |
| 558 | // TODO(1240712): NewSpace::Double has a return value which is |
| 559 | // ignored here. |
| 560 | new_space_->Double(); |
| 561 | new_space_growth_limit_ *= 2; |
| 562 | } |
| 563 | |
| 564 | // Flip the semispaces. After flipping, to space is empty, from space has |
| 565 | // live objects. |
| 566 | new_space_->Flip(); |
| 567 | new_space_->ResetAllocationInfo(); |
| 568 | |
| 569 | // We need to sweep newly copied objects which can be in either the to space |
| 570 | // or the old space. For to space objects, we use a mark. Newly copied |
| 571 | // objects lie between the mark and the allocation top. For objects |
| 572 | // promoted to old space, we write their addresses downward from the top of |
| 573 | // the new space. Sweeping newly promoted objects requires an allocation |
| 574 | // pointer and a mark. Note that the allocation pointer 'top' actually |
| 575 | // moves downward from the high address in the to space. |
| 576 | // |
| 577 | // There is guaranteed to be enough room at the top of the to space for the |
| 578 | // addresses of promoted objects: every object promoted frees up its size in |
| 579 | // bytes from the top of the new space, and objects are at least one pointer |
| 580 | // in size. Using the new space to record promoted addresses makes the |
| 581 | // scavenge collector agnostic to the allocation strategy (eg, linear or |
| 582 | // free-list) used in old space. |
| 583 | Address new_mark = new_space_->ToSpaceLow(); |
| 584 | Address promoted_mark = new_space_->ToSpaceHigh(); |
| 585 | promoted_top = new_space_->ToSpaceHigh(); |
| 586 | |
| 587 | CopyVisitor copy_visitor; |
| 588 | // Copy roots. |
| 589 | IterateRoots(©_visitor); |
| 590 | |
| 591 | // Copy objects reachable from the old generation. By definition, there |
| 592 | // are no intergenerational pointers in code space. |
| 593 | IterateRSet(old_space_, &CopyObject); |
| 594 | IterateRSet(map_space_, &CopyObject); |
| 595 | lo_space_->IterateRSet(&CopyObject); |
| 596 | |
| 597 | bool has_processed_weak_pointers = false; |
| 598 | |
| 599 | while (true) { |
| 600 | ASSERT(new_mark <= new_space_->top()); |
| 601 | ASSERT(promoted_mark >= promoted_top); |
| 602 | |
| 603 | // Copy objects reachable from newly copied objects. |
| 604 | while (new_mark < new_space_->top() || promoted_mark > promoted_top) { |
| 605 | // Sweep newly copied objects in the to space. The allocation pointer |
| 606 | // can change during sweeping. |
| 607 | Address previous_top = new_space_->top(); |
| 608 | SemiSpaceIterator new_it(new_space_, new_mark); |
| 609 | while (new_it.has_next()) { |
| 610 | new_it.next()->Iterate(©_visitor); |
| 611 | } |
| 612 | new_mark = previous_top; |
| 613 | |
| 614 | // Sweep newly copied objects in the old space. The promotion 'top' |
| 615 | // pointer could change during sweeping. |
| 616 | previous_top = promoted_top; |
| 617 | for (Address current = promoted_mark - kPointerSize; |
| 618 | current >= previous_top; |
| 619 | current -= kPointerSize) { |
| 620 | HeapObject* object = HeapObject::cast(Memory::Object_at(current)); |
| 621 | object->Iterate(©_visitor); |
| 622 | UpdateRSet(object); |
| 623 | } |
| 624 | promoted_mark = previous_top; |
| 625 | } |
| 626 | |
| 627 | if (has_processed_weak_pointers) break; // We are done. |
| 628 | // Copy objects reachable from weak pointers. |
| 629 | GlobalHandles::IterateWeakRoots(©_visitor); |
| 630 | has_processed_weak_pointers = true; |
| 631 | } |
| 632 | |
| 633 | // Set age mark. |
| 634 | new_space_->set_age_mark(new_mark); |
| 635 | |
| 636 | LOG(ResourceEvent("scavenge", "end")); |
| 637 | |
| 638 | gc_state_ = NOT_IN_GC; |
| 639 | } |
| 640 | |
| 641 | |
| 642 | void Heap::ClearRSetRange(Address start, int size_in_bytes) { |
| 643 | uint32_t start_bit; |
| 644 | Address start_word_address = |
| 645 | Page::ComputeRSetBitPosition(start, 0, &start_bit); |
| 646 | uint32_t end_bit; |
| 647 | Address end_word_address = |
| 648 | Page::ComputeRSetBitPosition(start + size_in_bytes - kIntSize, |
| 649 | 0, |
| 650 | &end_bit); |
| 651 | |
| 652 | // We want to clear the bits in the starting word starting with the |
| 653 | // first bit, and in the ending word up to and including the last |
| 654 | // bit. Build a pair of bitmasks to do that. |
| 655 | uint32_t start_bitmask = start_bit - 1; |
| 656 | uint32_t end_bitmask = ~((end_bit << 1) - 1); |
| 657 | |
| 658 | // If the start address and end address are the same, we mask that |
| 659 | // word once, otherwise mask the starting and ending word |
| 660 | // separately and all the ones in between. |
| 661 | if (start_word_address == end_word_address) { |
| 662 | Memory::uint32_at(start_word_address) &= (start_bitmask | end_bitmask); |
| 663 | } else { |
| 664 | Memory::uint32_at(start_word_address) &= start_bitmask; |
| 665 | Memory::uint32_at(end_word_address) &= end_bitmask; |
| 666 | start_word_address += kIntSize; |
| 667 | memset(start_word_address, 0, end_word_address - start_word_address); |
| 668 | } |
| 669 | } |
| 670 | |
| 671 | |
| 672 | class UpdateRSetVisitor: public ObjectVisitor { |
| 673 | public: |
| 674 | |
| 675 | void VisitPointer(Object** p) { |
| 676 | UpdateRSet(p); |
| 677 | } |
| 678 | |
| 679 | void VisitPointers(Object** start, Object** end) { |
| 680 | // Update a store into slots [start, end), used (a) to update remembered |
| 681 | // set when promoting a young object to old space or (b) to rebuild |
| 682 | // remembered sets after a mark-compact collection. |
| 683 | for (Object** p = start; p < end; p++) UpdateRSet(p); |
| 684 | } |
| 685 | private: |
| 686 | |
| 687 | void UpdateRSet(Object** p) { |
| 688 | // The remembered set should not be set. It should be clear for objects |
| 689 | // newly copied to old space, and it is cleared before rebuilding in the |
| 690 | // mark-compact collector. |
| 691 | ASSERT(!Page::IsRSetSet(reinterpret_cast<Address>(p), 0)); |
| 692 | if (Heap::InNewSpace(*p)) { |
| 693 | Page::SetRSet(reinterpret_cast<Address>(p), 0); |
| 694 | } |
| 695 | } |
| 696 | }; |
| 697 | |
| 698 | |
| 699 | int Heap::UpdateRSet(HeapObject* obj) { |
| 700 | ASSERT(!InNewSpace(obj)); |
| 701 | // Special handling of fixed arrays to iterate the body based on the start |
| 702 | // address and offset. Just iterating the pointers as in UpdateRSetVisitor |
| 703 | // will not work because Page::SetRSet needs to have the start of the |
| 704 | // object. |
| 705 | if (obj->IsFixedArray()) { |
| 706 | FixedArray* array = FixedArray::cast(obj); |
| 707 | int length = array->length(); |
| 708 | for (int i = 0; i < length; i++) { |
| 709 | int offset = FixedArray::kHeaderSize + i * kPointerSize; |
| 710 | ASSERT(!Page::IsRSetSet(obj->address(), offset)); |
| 711 | if (Heap::InNewSpace(array->get(i))) { |
| 712 | Page::SetRSet(obj->address(), offset); |
| 713 | } |
| 714 | } |
| 715 | } else if (!obj->IsCode()) { |
| 716 | // Skip code object, we know it does not contain inter-generational |
| 717 | // pointers. |
| 718 | UpdateRSetVisitor v; |
| 719 | obj->Iterate(&v); |
| 720 | } |
| 721 | return obj->Size(); |
| 722 | } |
| 723 | |
| 724 | |
| 725 | void Heap::RebuildRSets() { |
| 726 | // By definition, we do not care about remembered set bits in code space. |
| 727 | map_space_->ClearRSet(); |
| 728 | RebuildRSets(map_space_); |
| 729 | |
| 730 | old_space_->ClearRSet(); |
| 731 | RebuildRSets(old_space_); |
| 732 | |
| 733 | Heap::lo_space_->ClearRSet(); |
| 734 | RebuildRSets(lo_space_); |
| 735 | } |
| 736 | |
| 737 | |
| 738 | void Heap::RebuildRSets(PagedSpace* space) { |
| 739 | HeapObjectIterator it(space); |
| 740 | while (it.has_next()) Heap::UpdateRSet(it.next()); |
| 741 | } |
| 742 | |
| 743 | |
| 744 | void Heap::RebuildRSets(LargeObjectSpace* space) { |
| 745 | LargeObjectIterator it(space); |
| 746 | while (it.has_next()) Heap::UpdateRSet(it.next()); |
| 747 | } |
| 748 | |
| 749 | |
| 750 | #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| 751 | void Heap::RecordCopiedObject(HeapObject* obj) { |
| 752 | bool should_record = false; |
| 753 | #ifdef DEBUG |
| 754 | should_record = FLAG_heap_stats; |
| 755 | #endif |
| 756 | #ifdef ENABLE_LOGGING_AND_PROFILING |
| 757 | should_record = should_record || FLAG_log_gc; |
| 758 | #endif |
| 759 | if (should_record) { |
| 760 | if (new_space_->Contains(obj)) { |
| 761 | new_space_->RecordAllocation(obj); |
| 762 | } else { |
| 763 | new_space_->RecordPromotion(obj); |
| 764 | } |
| 765 | } |
| 766 | } |
| 767 | #endif // defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| 768 | |
| 769 | |
| 770 | HeapObject* Heap::MigrateObject(HeapObject** source_p, |
| 771 | HeapObject* target, |
| 772 | int size) { |
| 773 | void** src = reinterpret_cast<void**>((*source_p)->address()); |
| 774 | void** dst = reinterpret_cast<void**>(target->address()); |
| 775 | int counter = size/kPointerSize - 1; |
| 776 | do { |
| 777 | *dst++ = *src++; |
| 778 | } while (counter-- > 0); |
| 779 | |
| 780 | // Set forwarding pointers, cannot use Map::cast because it asserts |
| 781 | // the value type to be Map. |
| 782 | (*source_p)->set_map(reinterpret_cast<Map*>(target)); |
| 783 | |
| 784 | // Update NewSpace stats if necessary. |
| 785 | #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| 786 | RecordCopiedObject(target); |
| 787 | #endif |
| 788 | |
| 789 | return target; |
| 790 | } |
| 791 | |
| 792 | |
| 793 | void Heap::CopyObject(HeapObject** p) { |
| 794 | ASSERT(InFromSpace(*p)); |
| 795 | |
| 796 | HeapObject* object = *p; |
| 797 | |
| 798 | // We use the first word (where the map pointer usually is) of a |
| 799 | // HeapObject to record the forwarding pointer. A forwarding pointer can |
| 800 | // point to the old space, the code space, or the to space of the new |
| 801 | // generation. |
| 802 | HeapObject* first_word = object->map(); |
| 803 | |
| 804 | // If the first word (where the map pointer is) is not a map pointer, the |
| 805 | // object has already been copied. We do not use first_word->IsMap() |
| 806 | // because we know that first_word always has the heap object tag. |
| 807 | if (first_word->map()->instance_type() != MAP_TYPE) { |
| 808 | *p = first_word; |
| 809 | return; |
| 810 | } |
| 811 | |
| 812 | // Optimization: Bypass ConsString objects where the right-hand side is |
| 813 | // Heap::empty_string(). We do not use object->IsConsString because we |
| 814 | // already know that object has the heap object tag. |
| 815 | InstanceType type = Map::cast(first_word)->instance_type(); |
| 816 | if (type < FIRST_NONSTRING_TYPE && |
| 817 | String::cast(object)->representation_tag() == kConsStringTag && |
| 818 | ConsString::cast(object)->second() == Heap::empty_string()) { |
| 819 | object = HeapObject::cast(ConsString::cast(object)->first()); |
| 820 | *p = object; |
| 821 | // After patching *p we have to repeat the checks that object is in the |
| 822 | // active semispace of the young generation and not already copied. |
| 823 | if (!InFromSpace(object)) return; |
| 824 | first_word = object->map(); |
| 825 | if (first_word->map()->instance_type() != MAP_TYPE) { |
| 826 | *p = first_word; |
| 827 | return; |
| 828 | } |
| 829 | type = Map::cast(first_word)->instance_type(); |
| 830 | } |
| 831 | |
| 832 | int object_size = object->SizeFromMap(Map::cast(first_word)); |
| 833 | Object* result; |
| 834 | // If the object should be promoted, we try to copy it to old space. |
| 835 | if (ShouldBePromoted(object->address(), object_size)) { |
| 836 | // Heap numbers and sequential strings are promoted to code space, all |
| 837 | // other object types are promoted to old space. We do not use |
| 838 | // object->IsHeapNumber() and object->IsSeqString() because we already |
| 839 | // know that object has the heap object tag. |
| 840 | bool has_pointers = |
| 841 | type != HEAP_NUMBER_TYPE && |
| 842 | (type >= FIRST_NONSTRING_TYPE || |
| 843 | String::cast(object)->representation_tag() != kSeqStringTag); |
| 844 | if (has_pointers) { |
| 845 | result = old_space_->AllocateRaw(object_size); |
| 846 | } else { |
| 847 | result = code_space_->AllocateRaw(object_size); |
| 848 | } |
| 849 | |
| 850 | if (!result->IsFailure()) { |
| 851 | *p = MigrateObject(p, HeapObject::cast(result), object_size); |
| 852 | if (has_pointers) { |
| 853 | // Record the object's address at the top of the to space, to allow |
| 854 | // it to be swept by the scavenger. |
| 855 | promoted_top -= kPointerSize; |
| 856 | Memory::Object_at(promoted_top) = *p; |
| 857 | } else { |
| 858 | #ifdef DEBUG |
| 859 | // Objects promoted to the code space should not have pointers to |
| 860 | // new space. |
| 861 | VerifyCodeSpacePointersVisitor v; |
| 862 | (*p)->Iterate(&v); |
| 863 | #endif |
| 864 | } |
| 865 | return; |
| 866 | } |
| 867 | } |
| 868 | |
| 869 | // The object should remain in new space or the old space allocation failed. |
| 870 | result = new_space_->AllocateRaw(object_size); |
| 871 | // Failed allocation at this point is utterly unexpected. |
| 872 | ASSERT(!result->IsFailure()); |
| 873 | *p = MigrateObject(p, HeapObject::cast(result), object_size); |
| 874 | } |
| 875 | |
| 876 | |
| 877 | Object* Heap::AllocatePartialMap(InstanceType instance_type, |
| 878 | int instance_size) { |
| 879 | Object* result = AllocateRawMap(Map::kSize); |
| 880 | if (result->IsFailure()) return result; |
| 881 | |
| 882 | // Map::cast cannot be used due to uninitialized map field. |
| 883 | reinterpret_cast<Map*>(result)->set_map(meta_map()); |
| 884 | reinterpret_cast<Map*>(result)->set_instance_type(instance_type); |
| 885 | reinterpret_cast<Map*>(result)->set_instance_size(instance_size); |
| 886 | reinterpret_cast<Map*>(result)->set_unused_property_fields(0); |
| 887 | return result; |
| 888 | } |
| 889 | |
| 890 | |
| 891 | Object* Heap::AllocateMap(InstanceType instance_type, int instance_size) { |
| 892 | Object* result = AllocateRawMap(Map::kSize); |
| 893 | if (result->IsFailure()) return result; |
| 894 | |
| 895 | Map* map = reinterpret_cast<Map*>(result); |
| 896 | map->set_map(meta_map()); |
| 897 | map->set_instance_type(instance_type); |
| 898 | map->set_prototype(null_value()); |
| 899 | map->set_constructor(null_value()); |
| 900 | map->set_instance_size(instance_size); |
| 901 | map->set_instance_descriptors(DescriptorArray::cast(empty_fixed_array())); |
| 902 | map->set_code_cache(empty_fixed_array()); |
| 903 | map->set_unused_property_fields(0); |
| 904 | map->set_bit_field(0); |
| 905 | return map; |
| 906 | } |
| 907 | |
| 908 | |
| 909 | bool Heap::CreateInitialMaps() { |
| 910 | Object* obj = AllocatePartialMap(MAP_TYPE, Map::kSize); |
| 911 | if (obj->IsFailure()) return false; |
| 912 | |
| 913 | // Map::cast cannot be used due to uninitialized map field. |
| 914 | meta_map_ = reinterpret_cast<Map*>(obj); |
| 915 | meta_map()->set_map(meta_map()); |
| 916 | |
| 917 | obj = AllocatePartialMap(FIXED_ARRAY_TYPE, Array::kHeaderSize); |
| 918 | if (obj->IsFailure()) return false; |
| 919 | fixed_array_map_ = Map::cast(obj); |
| 920 | |
| 921 | obj = AllocatePartialMap(ODDBALL_TYPE, Oddball::kSize); |
| 922 | if (obj->IsFailure()) return false; |
| 923 | oddball_map_ = Map::cast(obj); |
| 924 | |
| 925 | // Allocate the empty array |
| 926 | obj = AllocateEmptyFixedArray(); |
| 927 | if (obj->IsFailure()) return false; |
| 928 | empty_fixed_array_ = FixedArray::cast(obj); |
| 929 | |
| 930 | obj = Allocate(oddball_map(), CODE_SPACE); |
| 931 | if (obj->IsFailure()) return false; |
| 932 | null_value_ = obj; |
| 933 | |
| 934 | // Fix the instance_descriptors for the existing maps. |
| 935 | DescriptorArray* empty_descriptors = |
| 936 | DescriptorArray::cast(empty_fixed_array()); |
| 937 | |
| 938 | meta_map()->set_instance_descriptors(empty_descriptors); |
| 939 | meta_map()->set_code_cache(empty_fixed_array()); |
| 940 | |
| 941 | fixed_array_map()->set_instance_descriptors(empty_descriptors); |
| 942 | fixed_array_map()->set_code_cache(empty_fixed_array()); |
| 943 | |
| 944 | oddball_map()->set_instance_descriptors(empty_descriptors); |
| 945 | oddball_map()->set_code_cache(empty_fixed_array()); |
| 946 | |
| 947 | // Fix prototype object for existing maps. |
| 948 | meta_map()->set_prototype(null_value()); |
| 949 | meta_map()->set_constructor(null_value()); |
| 950 | |
| 951 | fixed_array_map()->set_prototype(null_value()); |
| 952 | fixed_array_map()->set_constructor(null_value()); |
| 953 | oddball_map()->set_prototype(null_value()); |
| 954 | oddball_map()->set_constructor(null_value()); |
| 955 | |
| 956 | obj = AllocateMap(HEAP_NUMBER_TYPE, HeapNumber::kSize); |
| 957 | if (obj->IsFailure()) return false; |
| 958 | heap_number_map_ = Map::cast(obj); |
| 959 | |
| 960 | obj = AllocateMap(PROXY_TYPE, Proxy::kSize); |
| 961 | if (obj->IsFailure()) return false; |
| 962 | proxy_map_ = Map::cast(obj); |
| 963 | |
| 964 | #define ALLOCATE_STRING_MAP(type, size, name) \ |
| 965 | obj = AllocateMap(type, size); \ |
| 966 | if (obj->IsFailure()) return false; \ |
| 967 | name##_map_ = Map::cast(obj); |
| 968 | STRING_TYPE_LIST(ALLOCATE_STRING_MAP); |
| 969 | #undef ALLOCATE_STRING_MAP |
| 970 | |
| 971 | obj = AllocateMap(SHORT_STRING_TYPE, TwoByteString::kHeaderSize); |
| 972 | if (obj->IsFailure()) return false; |
| 973 | undetectable_short_string_map_ = Map::cast(obj); |
| 974 | undetectable_short_string_map_->set_is_undetectable(); |
| 975 | |
| 976 | obj = AllocateMap(MEDIUM_STRING_TYPE, TwoByteString::kHeaderSize); |
| 977 | if (obj->IsFailure()) return false; |
| 978 | undetectable_medium_string_map_ = Map::cast(obj); |
| 979 | undetectable_medium_string_map_->set_is_undetectable(); |
| 980 | |
| 981 | obj = AllocateMap(LONG_STRING_TYPE, TwoByteString::kHeaderSize); |
| 982 | if (obj->IsFailure()) return false; |
| 983 | undetectable_long_string_map_ = Map::cast(obj); |
| 984 | undetectable_long_string_map_->set_is_undetectable(); |
| 985 | |
| 986 | obj = AllocateMap(SHORT_ASCII_STRING_TYPE, AsciiString::kHeaderSize); |
| 987 | if (obj->IsFailure()) return false; |
| 988 | undetectable_short_ascii_string_map_ = Map::cast(obj); |
| 989 | undetectable_short_ascii_string_map_->set_is_undetectable(); |
| 990 | |
| 991 | obj = AllocateMap(MEDIUM_ASCII_STRING_TYPE, AsciiString::kHeaderSize); |
| 992 | if (obj->IsFailure()) return false; |
| 993 | undetectable_medium_ascii_string_map_ = Map::cast(obj); |
| 994 | undetectable_medium_ascii_string_map_->set_is_undetectable(); |
| 995 | |
| 996 | obj = AllocateMap(LONG_ASCII_STRING_TYPE, AsciiString::kHeaderSize); |
| 997 | if (obj->IsFailure()) return false; |
| 998 | undetectable_long_ascii_string_map_ = Map::cast(obj); |
| 999 | undetectable_long_ascii_string_map_->set_is_undetectable(); |
| 1000 | |
| 1001 | obj = AllocateMap(BYTE_ARRAY_TYPE, Array::kHeaderSize); |
| 1002 | if (obj->IsFailure()) return false; |
| 1003 | byte_array_map_ = Map::cast(obj); |
| 1004 | |
| 1005 | obj = AllocateMap(CODE_TYPE, Code::kHeaderSize); |
| 1006 | if (obj->IsFailure()) return false; |
| 1007 | code_map_ = Map::cast(obj); |
| 1008 | |
| 1009 | obj = AllocateMap(FILLER_TYPE, kPointerSize); |
| 1010 | if (obj->IsFailure()) return false; |
| 1011 | one_word_filler_map_ = Map::cast(obj); |
| 1012 | |
| 1013 | obj = AllocateMap(FILLER_TYPE, 2 * kPointerSize); |
| 1014 | if (obj->IsFailure()) return false; |
| 1015 | two_word_filler_map_ = Map::cast(obj); |
| 1016 | |
| 1017 | #define ALLOCATE_STRUCT_MAP(NAME, Name, name) \ |
| 1018 | obj = AllocateMap(NAME##_TYPE, Name::kSize); \ |
| 1019 | if (obj->IsFailure()) return false; \ |
| 1020 | name##_map_ = Map::cast(obj); |
| 1021 | STRUCT_LIST(ALLOCATE_STRUCT_MAP) |
| 1022 | #undef ALLOCATE_STRUCT_MAP |
| 1023 | |
| 1024 | obj = AllocateMap(FIXED_ARRAY_TYPE, HeapObject::kSize); |
| 1025 | if (obj->IsFailure()) return false; |
| 1026 | hash_table_map_ = Map::cast(obj); |
| 1027 | |
| 1028 | obj = AllocateMap(FIXED_ARRAY_TYPE, HeapObject::kSize); |
| 1029 | if (obj->IsFailure()) return false; |
| 1030 | context_map_ = Map::cast(obj); |
| 1031 | |
| 1032 | obj = AllocateMap(FIXED_ARRAY_TYPE, HeapObject::kSize); |
| 1033 | if (obj->IsFailure()) return false; |
| 1034 | global_context_map_ = Map::cast(obj); |
| 1035 | |
| 1036 | obj = AllocateMap(JS_FUNCTION_TYPE, JSFunction::kSize); |
| 1037 | if (obj->IsFailure()) return false; |
| 1038 | boilerplate_function_map_ = Map::cast(obj); |
| 1039 | |
| 1040 | obj = AllocateMap(SHARED_FUNCTION_INFO_TYPE, SharedFunctionInfo::kSize); |
| 1041 | if (obj->IsFailure()) return false; |
| 1042 | shared_function_info_map_ = Map::cast(obj); |
| 1043 | |
| 1044 | return true; |
| 1045 | } |
| 1046 | |
| 1047 | |
| 1048 | Object* Heap::AllocateHeapNumber(double value, PretenureFlag pretenure) { |
| 1049 | // Statically ensure that it is safe to allocate heap numbers in paged |
| 1050 | // spaces. |
| 1051 | STATIC_ASSERT(HeapNumber::kSize <= Page::kMaxHeapObjectSize); |
| 1052 | AllocationSpace space = (pretenure == TENURED) ? CODE_SPACE : NEW_SPACE; |
| 1053 | Object* result = AllocateRaw(HeapNumber::kSize, space); |
| 1054 | if (result->IsFailure()) return result; |
| 1055 | |
| 1056 | HeapObject::cast(result)->set_map(heap_number_map()); |
| 1057 | HeapNumber::cast(result)->set_value(value); |
| 1058 | return result; |
| 1059 | } |
| 1060 | |
| 1061 | |
| 1062 | Object* Heap::AllocateHeapNumber(double value) { |
| 1063 | // This version of AllocateHeapNumber is optimized for |
| 1064 | // allocation in new space. |
| 1065 | STATIC_ASSERT(HeapNumber::kSize <= Page::kMaxHeapObjectSize); |
| 1066 | ASSERT(allocation_allowed_ && gc_state_ == NOT_IN_GC); |
| 1067 | Object* result = new_space_->AllocateRaw(HeapNumber::kSize); |
| 1068 | if (result->IsFailure()) return result; |
| 1069 | HeapObject::cast(result)->set_map(heap_number_map()); |
| 1070 | HeapNumber::cast(result)->set_value(value); |
| 1071 | return result; |
| 1072 | } |
| 1073 | |
| 1074 | |
| 1075 | Object* Heap::CreateOddball(Map* map, |
| 1076 | const char* to_string, |
| 1077 | Object* to_number) { |
| 1078 | Object* result = Allocate(map, CODE_SPACE); |
| 1079 | if (result->IsFailure()) return result; |
| 1080 | return Oddball::cast(result)->Initialize(to_string, to_number); |
| 1081 | } |
| 1082 | |
| 1083 | |
| 1084 | bool Heap::CreateApiObjects() { |
| 1085 | Object* obj; |
| 1086 | |
| 1087 | obj = AllocateMap(JS_OBJECT_TYPE, JSObject::kHeaderSize); |
| 1088 | if (obj->IsFailure()) return false; |
| 1089 | neander_map_ = Map::cast(obj); |
| 1090 | |
| 1091 | obj = Heap::AllocateJSObjectFromMap(neander_map_); |
| 1092 | if (obj->IsFailure()) return false; |
| 1093 | Object* elements = AllocateFixedArray(2); |
| 1094 | if (elements->IsFailure()) return false; |
| 1095 | FixedArray::cast(elements)->set(0, Smi::FromInt(0)); |
| 1096 | JSObject::cast(obj)->set_elements(FixedArray::cast(elements)); |
| 1097 | message_listeners_ = JSObject::cast(obj); |
| 1098 | |
| 1099 | obj = Heap::AllocateJSObjectFromMap(neander_map_); |
| 1100 | if (obj->IsFailure()) return false; |
| 1101 | elements = AllocateFixedArray(2); |
| 1102 | if (elements->IsFailure()) return false; |
| 1103 | FixedArray::cast(elements)->set(0, Smi::FromInt(0)); |
| 1104 | JSObject::cast(obj)->set_elements(FixedArray::cast(elements)); |
| 1105 | debug_event_listeners_ = JSObject::cast(obj); |
| 1106 | |
| 1107 | return true; |
| 1108 | } |
| 1109 | |
| 1110 | void Heap::CreateFixedStubs() { |
| 1111 | // Here we create roots for fixed stubs. They are needed at GC |
| 1112 | // for cooking and uncooking (check out frames.cc). |
| 1113 | // The eliminates the need for doing dictionary lookup in the |
| 1114 | // stub cache for these stubs. |
| 1115 | HandleScope scope; |
| 1116 | { |
| 1117 | CEntryStub stub; |
| 1118 | c_entry_code_ = *stub.GetCode(); |
| 1119 | } |
| 1120 | { |
| 1121 | CEntryDebugBreakStub stub; |
| 1122 | c_entry_debug_break_code_ = *stub.GetCode(); |
| 1123 | } |
| 1124 | { |
| 1125 | JSEntryStub stub; |
| 1126 | js_entry_code_ = *stub.GetCode(); |
| 1127 | } |
| 1128 | { |
| 1129 | JSConstructEntryStub stub; |
| 1130 | js_construct_entry_code_ = *stub.GetCode(); |
| 1131 | } |
| 1132 | } |
| 1133 | |
| 1134 | |
| 1135 | bool Heap::CreateInitialObjects() { |
| 1136 | Object* obj; |
| 1137 | |
| 1138 | // The -0 value must be set before NumberFromDouble works. |
| 1139 | obj = AllocateHeapNumber(-0.0, TENURED); |
| 1140 | if (obj->IsFailure()) return false; |
| 1141 | minus_zero_value_ = obj; |
| 1142 | ASSERT(signbit(minus_zero_value_->Number()) != 0); |
| 1143 | |
| 1144 | obj = AllocateHeapNumber(OS::nan_value(), TENURED); |
| 1145 | if (obj->IsFailure()) return false; |
| 1146 | nan_value_ = obj; |
| 1147 | |
| 1148 | obj = NumberFromDouble(INFINITY, TENURED); |
| 1149 | if (obj->IsFailure()) return false; |
| 1150 | infinity_value_ = obj; |
| 1151 | |
| 1152 | obj = NumberFromDouble(-INFINITY, TENURED); |
| 1153 | if (obj->IsFailure()) return false; |
| 1154 | negative_infinity_value_ = obj; |
| 1155 | |
| 1156 | obj = NumberFromDouble(DBL_MAX, TENURED); |
| 1157 | if (obj->IsFailure()) return false; |
| 1158 | number_max_value_ = obj; |
| 1159 | |
| 1160 | // C++ doesn't provide a constant for the smallest denormalized |
| 1161 | // double (approx. 5e-324) but only the smallest normalized one |
| 1162 | // which is somewhat bigger (approx. 2e-308). So we have to do |
| 1163 | // this raw conversion hack. |
| 1164 | uint64_t min_value_bits = 1L; |
| 1165 | double min_value = *reinterpret_cast<double*>(&min_value_bits); |
| 1166 | obj = NumberFromDouble(min_value, TENURED); |
| 1167 | if (obj->IsFailure()) return false; |
| 1168 | number_min_value_ = obj; |
| 1169 | |
| 1170 | obj = Allocate(oddball_map(), CODE_SPACE); |
| 1171 | if (obj->IsFailure()) return false; |
| 1172 | undefined_value_ = obj; |
| 1173 | ASSERT(!InNewSpace(undefined_value())); |
| 1174 | |
| 1175 | // Allocate initial symbol table. |
| 1176 | obj = SymbolTable::Allocate(kInitialSymbolTableSize); |
| 1177 | if (obj->IsFailure()) return false; |
| 1178 | symbol_table_ = obj; |
| 1179 | |
| 1180 | // Assign the print strings for oddballs after creating symboltable. |
| 1181 | Object* symbol = LookupAsciiSymbol("undefined"); |
| 1182 | if (symbol->IsFailure()) return false; |
| 1183 | Oddball::cast(undefined_value_)->set_to_string(String::cast(symbol)); |
| 1184 | Oddball::cast(undefined_value_)->set_to_number(nan_value_); |
| 1185 | |
| 1186 | // Assign the print strings for oddballs after creating symboltable. |
| 1187 | symbol = LookupAsciiSymbol("null"); |
| 1188 | if (symbol->IsFailure()) return false; |
| 1189 | Oddball::cast(null_value_)->set_to_string(String::cast(symbol)); |
| 1190 | Oddball::cast(null_value_)->set_to_number(Smi::FromInt(0)); |
| 1191 | |
| 1192 | // Allocate the null_value |
| 1193 | obj = Oddball::cast(null_value())->Initialize("null", Smi::FromInt(0)); |
| 1194 | if (obj->IsFailure()) return false; |
| 1195 | |
| 1196 | obj = CreateOddball(oddball_map(), "true", Smi::FromInt(1)); |
| 1197 | if (obj->IsFailure()) return false; |
| 1198 | true_value_ = obj; |
| 1199 | |
| 1200 | obj = CreateOddball(oddball_map(), "false", Smi::FromInt(0)); |
| 1201 | if (obj->IsFailure()) return false; |
| 1202 | false_value_ = obj; |
| 1203 | |
| 1204 | obj = CreateOddball(oddball_map(), "hole", Smi::FromInt(-1)); |
| 1205 | if (obj->IsFailure()) return false; |
| 1206 | the_hole_value_ = obj; |
| 1207 | |
| 1208 | // Allocate the empty string. |
| 1209 | obj = AllocateRawAsciiString(0, TENURED); |
| 1210 | if (obj->IsFailure()) return false; |
| 1211 | empty_string_ = String::cast(obj); |
| 1212 | |
| 1213 | #define SYMBOL_INITIALIZE(name, string) \ |
| 1214 | obj = LookupAsciiSymbol(string); \ |
| 1215 | if (obj->IsFailure()) return false; \ |
| 1216 | (name##_) = String::cast(obj); |
| 1217 | SYMBOL_LIST(SYMBOL_INITIALIZE) |
| 1218 | #undef SYMBOL_INITIALIZE |
| 1219 | |
| 1220 | // Allocate the proxy for __proto__. |
| 1221 | obj = AllocateProxy((Address) &Accessors::ObjectPrototype); |
| 1222 | if (obj->IsFailure()) return false; |
| 1223 | prototype_accessors_ = Proxy::cast(obj); |
| 1224 | |
| 1225 | // Allocate the code_stubs dictionary. |
| 1226 | obj = Dictionary::Allocate(4); |
| 1227 | if (obj->IsFailure()) return false; |
| 1228 | code_stubs_ = Dictionary::cast(obj); |
| 1229 | |
| 1230 | // Allocate the non_monomorphic_cache used in stub-cache.cc |
| 1231 | obj = Dictionary::Allocate(4); |
| 1232 | if (obj->IsFailure()) return false; |
| 1233 | non_monomorphic_cache_ = Dictionary::cast(obj); |
| 1234 | |
| 1235 | CreateFixedStubs(); |
| 1236 | |
| 1237 | // Allocate the number->string conversion cache |
| 1238 | obj = AllocateFixedArray(kNumberStringCacheSize * 2); |
| 1239 | if (obj->IsFailure()) return false; |
| 1240 | number_string_cache_ = FixedArray::cast(obj); |
| 1241 | |
| 1242 | // Allocate cache for single character strings. |
| 1243 | obj = AllocateFixedArray(String::kMaxAsciiCharCode+1); |
| 1244 | if (obj->IsFailure()) return false; |
| 1245 | single_character_string_cache_ = FixedArray::cast(obj); |
| 1246 | |
| 1247 | // Allocate cache for external strings pointing to native source code. |
| 1248 | obj = AllocateFixedArray(Natives::GetBuiltinsCount()); |
| 1249 | if (obj->IsFailure()) return false; |
| 1250 | natives_source_cache_ = FixedArray::cast(obj); |
| 1251 | |
| 1252 | return true; |
| 1253 | } |
| 1254 | |
| 1255 | |
| 1256 | static inline int double_get_hash(double d) { |
| 1257 | DoubleRepresentation rep(d); |
| 1258 | return ((static_cast<int>(rep.bits) ^ static_cast<int>(rep.bits >> 32)) & |
| 1259 | (Heap::kNumberStringCacheSize - 1)); |
| 1260 | } |
| 1261 | |
| 1262 | |
| 1263 | static inline int smi_get_hash(Smi* smi) { |
| 1264 | return (smi->value() & (Heap::kNumberStringCacheSize - 1)); |
| 1265 | } |
| 1266 | |
| 1267 | |
| 1268 | |
| 1269 | Object* Heap::GetNumberStringCache(Object* number) { |
| 1270 | int hash; |
| 1271 | if (number->IsSmi()) { |
| 1272 | hash = smi_get_hash(Smi::cast(number)); |
| 1273 | } else { |
| 1274 | hash = double_get_hash(number->Number()); |
| 1275 | } |
| 1276 | Object* key = number_string_cache_->get(hash * 2); |
| 1277 | if (key == number) { |
| 1278 | return String::cast(number_string_cache_->get(hash * 2 + 1)); |
| 1279 | } else if (key->IsHeapNumber() && |
| 1280 | number->IsHeapNumber() && |
| 1281 | key->Number() == number->Number()) { |
| 1282 | return String::cast(number_string_cache_->get(hash * 2 + 1)); |
| 1283 | } |
| 1284 | return undefined_value(); |
| 1285 | } |
| 1286 | |
| 1287 | |
| 1288 | void Heap::SetNumberStringCache(Object* number, String* string) { |
| 1289 | int hash; |
| 1290 | if (number->IsSmi()) { |
| 1291 | hash = smi_get_hash(Smi::cast(number)); |
| 1292 | number_string_cache_->set(hash * 2, number, FixedArray::SKIP_WRITE_BARRIER); |
| 1293 | } else { |
| 1294 | hash = double_get_hash(number->Number()); |
| 1295 | number_string_cache_->set(hash * 2, number); |
| 1296 | } |
| 1297 | number_string_cache_->set(hash * 2 + 1, string); |
| 1298 | } |
| 1299 | |
| 1300 | |
| 1301 | Object* Heap::SmiOrNumberFromDouble(double value, |
| 1302 | bool new_object, |
| 1303 | PretenureFlag pretenure) { |
| 1304 | // We need to distinguish the minus zero value and this cannot be |
| 1305 | // done after conversion to int. Doing this by comparing bit |
| 1306 | // patterns is faster than using fpclassify() et al. |
| 1307 | static const DoubleRepresentation plus_zero(0.0); |
| 1308 | static const DoubleRepresentation minus_zero(-0.0); |
| 1309 | static const DoubleRepresentation nan(OS::nan_value()); |
| 1310 | ASSERT(minus_zero_value_ != NULL); |
| 1311 | ASSERT(sizeof(plus_zero.value) == sizeof(plus_zero.bits)); |
| 1312 | |
| 1313 | DoubleRepresentation rep(value); |
| 1314 | if (rep.bits == plus_zero.bits) return Smi::FromInt(0); // not uncommon |
| 1315 | if (rep.bits == minus_zero.bits) { |
| 1316 | return new_object ? AllocateHeapNumber(-0.0, pretenure) |
| 1317 | : minus_zero_value_; |
| 1318 | } |
| 1319 | if (rep.bits == nan.bits) { |
| 1320 | return new_object |
| 1321 | ? AllocateHeapNumber(OS::nan_value(), pretenure) |
| 1322 | : nan_value_; |
| 1323 | } |
| 1324 | |
| 1325 | // Try to represent the value as a tagged small integer. |
| 1326 | int int_value = FastD2I(value); |
| 1327 | if (value == FastI2D(int_value) && Smi::IsValid(int_value)) { |
| 1328 | return Smi::FromInt(int_value); |
| 1329 | } |
| 1330 | |
| 1331 | // Materialize the value in the heap. |
| 1332 | return AllocateHeapNumber(value, pretenure); |
| 1333 | } |
| 1334 | |
| 1335 | |
| 1336 | Object* Heap::NewNumberFromDouble(double value, PretenureFlag pretenure) { |
| 1337 | return SmiOrNumberFromDouble(value, |
| 1338 | true /* number object must be new */, |
| 1339 | pretenure); |
| 1340 | } |
| 1341 | |
| 1342 | |
| 1343 | Object* Heap::NumberFromDouble(double value, PretenureFlag pretenure) { |
| 1344 | return SmiOrNumberFromDouble(value, |
| 1345 | false /* use preallocated NaN, -0.0 */, |
| 1346 | pretenure); |
| 1347 | } |
| 1348 | |
| 1349 | |
| 1350 | Object* Heap::AllocateProxy(Address proxy, PretenureFlag pretenure) { |
| 1351 | // Statically ensure that it is safe to allocate proxies in paged spaces. |
| 1352 | STATIC_ASSERT(Proxy::kSize <= Page::kMaxHeapObjectSize); |
| 1353 | AllocationSpace space = (pretenure == TENURED) ? OLD_SPACE : NEW_SPACE; |
| 1354 | Object* result = Allocate(proxy_map(), space); |
| 1355 | if (result->IsFailure()) return result; |
| 1356 | |
| 1357 | Proxy::cast(result)->set_proxy(proxy); |
| 1358 | return result; |
| 1359 | } |
| 1360 | |
| 1361 | |
| 1362 | Object* Heap::AllocateSharedFunctionInfo(Object* name) { |
| 1363 | Object* result = Allocate(shared_function_info_map(), NEW_SPACE); |
| 1364 | if (result->IsFailure()) return result; |
| 1365 | |
| 1366 | SharedFunctionInfo* share = SharedFunctionInfo::cast(result); |
| 1367 | share->set_name(name); |
| 1368 | Code* illegal = Builtins::builtin(Builtins::Illegal); |
| 1369 | share->set_code(illegal); |
| 1370 | share->set_expected_nof_properties(0); |
| 1371 | share->set_length(0); |
| 1372 | share->set_formal_parameter_count(0); |
| 1373 | share->set_instance_class_name(Object_symbol()); |
| 1374 | share->set_function_data(undefined_value()); |
| 1375 | share->set_lazy_load_data(undefined_value()); |
| 1376 | share->set_script(undefined_value()); |
| 1377 | share->set_start_position_and_type(0); |
| 1378 | share->set_debug_info(undefined_value()); |
| 1379 | return result; |
| 1380 | } |
| 1381 | |
| 1382 | |
| 1383 | Object* Heap::AllocateConsString(String* first, String* second) { |
| 1384 | int length = first->length() + second->length(); |
| 1385 | bool is_ascii = first->is_ascii() && second->is_ascii(); |
| 1386 | |
| 1387 | // If the resulting string is small make a flat string. |
| 1388 | if (length < ConsString::kMinLength) { |
| 1389 | Object* result = is_ascii |
| 1390 | ? AllocateRawAsciiString(length) |
| 1391 | : AllocateRawTwoByteString(length); |
| 1392 | if (result->IsFailure()) return result; |
| 1393 | // Copy the characters into the new object. |
| 1394 | String* string_result = String::cast(result); |
| 1395 | int first_length = first->length(); |
| 1396 | // Copy the content of the first string. |
| 1397 | for (int i = 0; i < first_length; i++) { |
| 1398 | string_result->Set(i, first->Get(i)); |
| 1399 | } |
| 1400 | int second_length = second->length(); |
| 1401 | // Copy the content of the first string. |
| 1402 | for (int i = 0; i < second_length; i++) { |
| 1403 | string_result->Set(first_length + i, second->Get(i)); |
| 1404 | } |
| 1405 | return result; |
| 1406 | } |
| 1407 | |
| 1408 | Map* map; |
| 1409 | if (length <= String::kMaxShortStringSize) { |
| 1410 | map = is_ascii ? short_cons_ascii_string_map() |
| 1411 | : short_cons_string_map(); |
| 1412 | } else if (length <= String::kMaxMediumStringSize) { |
| 1413 | map = is_ascii ? medium_cons_ascii_string_map() |
| 1414 | : medium_cons_string_map(); |
| 1415 | } else { |
| 1416 | map = is_ascii ? long_cons_ascii_string_map() |
| 1417 | : long_cons_string_map(); |
| 1418 | } |
| 1419 | |
| 1420 | Object* result = Allocate(map, NEW_SPACE); |
| 1421 | if (result->IsFailure()) return result; |
| 1422 | |
| 1423 | ConsString* cons_string = ConsString::cast(result); |
| 1424 | cons_string->set_first(first); |
| 1425 | cons_string->set_second(second); |
| 1426 | cons_string->set_length(length); |
| 1427 | |
| 1428 | return result; |
| 1429 | } |
| 1430 | |
| 1431 | |
| 1432 | Object* Heap::AllocateSlicedString(String* buffer, int start, int end) { |
| 1433 | int length = end - start; |
| 1434 | |
| 1435 | // If the resulting string is small make a sub string. |
| 1436 | if (end - start <= SlicedString::kMinLength) { |
| 1437 | return Heap::AllocateSubString(buffer, start, end); |
| 1438 | } |
| 1439 | |
| 1440 | Map* map; |
| 1441 | if (length <= String::kMaxShortStringSize) { |
| 1442 | map = buffer->is_ascii() ? short_sliced_ascii_string_map() |
| 1443 | : short_sliced_string_map(); |
| 1444 | } else if (length <= String::kMaxMediumStringSize) { |
| 1445 | map = buffer->is_ascii() ? medium_sliced_ascii_string_map() |
| 1446 | : medium_sliced_string_map(); |
| 1447 | } else { |
| 1448 | map = buffer->is_ascii() ? long_sliced_ascii_string_map() |
| 1449 | : long_sliced_string_map(); |
| 1450 | } |
| 1451 | |
| 1452 | Object* result = Allocate(map, NEW_SPACE); |
| 1453 | if (result->IsFailure()) return result; |
| 1454 | |
| 1455 | SlicedString* sliced_string = SlicedString::cast(result); |
| 1456 | sliced_string->set_buffer(buffer); |
| 1457 | sliced_string->set_start(start); |
| 1458 | sliced_string->set_length(length); |
| 1459 | |
| 1460 | return result; |
| 1461 | } |
| 1462 | |
| 1463 | |
| 1464 | Object* Heap::AllocateSubString(String* buffer, int start, int end) { |
| 1465 | int length = end - start; |
| 1466 | |
| 1467 | // Make an attempt to flatten the buffer to reduce access time. |
| 1468 | buffer->TryFlatten(); |
| 1469 | |
| 1470 | Object* result = buffer->is_ascii() |
| 1471 | ? AllocateRawAsciiString(length) |
| 1472 | : AllocateRawTwoByteString(length); |
| 1473 | if (result->IsFailure()) return result; |
| 1474 | |
| 1475 | // Copy the characters into the new object. |
| 1476 | String* string_result = String::cast(result); |
| 1477 | for (int i = 0; i < length; i++) { |
| 1478 | string_result->Set(i, buffer->Get(start + i)); |
| 1479 | } |
| 1480 | return result; |
| 1481 | } |
| 1482 | |
| 1483 | |
| 1484 | Object* Heap::AllocateExternalStringFromAscii( |
| 1485 | ExternalAsciiString::Resource* resource) { |
| 1486 | Map* map; |
| 1487 | int length = resource->length(); |
| 1488 | if (length <= String::kMaxShortStringSize) { |
| 1489 | map = short_external_ascii_string_map(); |
| 1490 | } else if (length <= String::kMaxMediumStringSize) { |
| 1491 | map = medium_external_ascii_string_map(); |
| 1492 | } else { |
| 1493 | map = long_external_ascii_string_map(); |
| 1494 | } |
| 1495 | |
| 1496 | Object* result = Allocate(map, NEW_SPACE); |
| 1497 | if (result->IsFailure()) return result; |
| 1498 | |
| 1499 | ExternalAsciiString* external_string = ExternalAsciiString::cast(result); |
| 1500 | external_string->set_length(length); |
| 1501 | external_string->set_resource(resource); |
| 1502 | |
| 1503 | return result; |
| 1504 | } |
| 1505 | |
| 1506 | |
| 1507 | Object* Heap::AllocateExternalStringFromTwoByte( |
| 1508 | ExternalTwoByteString::Resource* resource) { |
| 1509 | Map* map; |
| 1510 | int length = resource->length(); |
| 1511 | if (length <= String::kMaxShortStringSize) { |
| 1512 | map = short_external_string_map(); |
| 1513 | } else if (length <= String::kMaxMediumStringSize) { |
| 1514 | map = medium_external_string_map(); |
| 1515 | } else { |
| 1516 | map = long_external_string_map(); |
| 1517 | } |
| 1518 | |
| 1519 | Object* result = Allocate(map, NEW_SPACE); |
| 1520 | if (result->IsFailure()) return result; |
| 1521 | |
| 1522 | ExternalTwoByteString* external_string = ExternalTwoByteString::cast(result); |
| 1523 | external_string->set_length(length); |
| 1524 | external_string->set_resource(resource); |
| 1525 | |
| 1526 | return result; |
| 1527 | } |
| 1528 | |
| 1529 | |
| 1530 | Object* Heap:: LookupSingleCharacterStringFromCode(uint16_t code) { |
| 1531 | if (code <= String::kMaxAsciiCharCode) { |
| 1532 | Object* value = Heap::single_character_string_cache()->get(code); |
| 1533 | if (value != Heap::undefined_value()) return value; |
| 1534 | Object* result = Heap::AllocateRawAsciiString(1); |
| 1535 | if (result->IsFailure()) return result; |
| 1536 | String::cast(result)->Set(0, code); |
| 1537 | Heap::single_character_string_cache()->set(code, result); |
| 1538 | return result; |
| 1539 | } |
| 1540 | Object* result = Heap::AllocateRawTwoByteString(1); |
| 1541 | if (result->IsFailure()) return result; |
| 1542 | String::cast(result)->Set(0, code); |
| 1543 | return result; |
| 1544 | } |
| 1545 | |
| 1546 | |
| 1547 | Object* Heap::AllocateByteArray(int length) { |
| 1548 | int size = ByteArray::SizeFor(length); |
| 1549 | AllocationSpace space = size > MaxHeapObjectSize() ? LO_SPACE : NEW_SPACE; |
| 1550 | |
| 1551 | Object* result = AllocateRaw(size, space); |
| 1552 | if (result->IsFailure()) return result; |
| 1553 | |
| 1554 | reinterpret_cast<Array*>(result)->set_map(byte_array_map()); |
| 1555 | reinterpret_cast<Array*>(result)->set_length(length); |
| 1556 | return result; |
| 1557 | } |
| 1558 | |
| 1559 | |
| 1560 | Object* Heap::CreateCode(const CodeDesc& desc, |
| 1561 | ScopeInfo<>* sinfo, |
| 1562 | Code::Flags flags) { |
| 1563 | // Compute size |
| 1564 | int body_size = RoundUp(desc.instr_size + desc.reloc_size, kObjectAlignment); |
| 1565 | int sinfo_size = 0; |
| 1566 | if (sinfo != NULL) sinfo_size = sinfo->Serialize(NULL); |
| 1567 | int obj_size = Code::SizeFor(body_size, sinfo_size); |
| 1568 | AllocationSpace space = |
| 1569 | (obj_size > MaxHeapObjectSize()) ? LO_SPACE : CODE_SPACE; |
| 1570 | |
| 1571 | Object* result = AllocateRaw(obj_size, space); |
| 1572 | if (result->IsFailure()) return result; |
| 1573 | |
| 1574 | // Initialize the object |
| 1575 | HeapObject::cast(result)->set_map(code_map()); |
| 1576 | Code* code = Code::cast(result); |
| 1577 | code->set_instruction_size(desc.instr_size); |
| 1578 | code->set_relocation_size(desc.reloc_size); |
| 1579 | code->set_sinfo_size(sinfo_size); |
| 1580 | code->set_flags(flags); |
| 1581 | code->set_ic_flag(Code::IC_TARGET_IS_ADDRESS); |
| 1582 | code->CopyFrom(desc); // migrate generated code |
| 1583 | if (sinfo != NULL) sinfo->Serialize(code); // write scope info |
| 1584 | |
| 1585 | #ifdef DEBUG |
| 1586 | code->Verify(); |
| 1587 | #endif |
| 1588 | |
| 1589 | CPU::FlushICache(code->instruction_start(), code->instruction_size()); |
| 1590 | |
| 1591 | return code; |
| 1592 | } |
| 1593 | |
| 1594 | |
| 1595 | Object* Heap::CopyCode(Code* code) { |
| 1596 | // Allocate an object the same size as the code object. |
| 1597 | int obj_size = code->Size(); |
| 1598 | AllocationSpace space = |
| 1599 | (obj_size > MaxHeapObjectSize()) ? LO_SPACE : CODE_SPACE; |
| 1600 | Object* result = AllocateRaw(obj_size, space); |
| 1601 | if (result->IsFailure()) return result; |
| 1602 | |
| 1603 | // Copy code object. |
| 1604 | Address old_addr = code->address(); |
| 1605 | Address new_addr = reinterpret_cast<HeapObject*>(result)->address(); |
| 1606 | memcpy(new_addr, old_addr, obj_size); |
| 1607 | |
| 1608 | // Relocate the copy. |
| 1609 | Code* new_code = Code::cast(result); |
| 1610 | new_code->Relocate(new_addr - old_addr); |
| 1611 | |
| 1612 | CPU::FlushICache(new_code->instruction_start(), new_code->instruction_size()); |
| 1613 | |
| 1614 | return new_code; |
| 1615 | } |
| 1616 | |
| 1617 | |
| 1618 | Object* Heap::Allocate(Map* map, AllocationSpace space) { |
| 1619 | ASSERT(gc_state_ == NOT_IN_GC); |
| 1620 | ASSERT(map->instance_type() != MAP_TYPE); |
| 1621 | Object* result = AllocateRaw(map->instance_size(), space); |
| 1622 | if (result->IsFailure()) return result; |
| 1623 | HeapObject::cast(result)->set_map(map); |
| 1624 | return result; |
| 1625 | } |
| 1626 | |
| 1627 | |
| 1628 | Object* Heap::InitializeFunction(JSFunction* function, |
| 1629 | SharedFunctionInfo* shared, |
| 1630 | Object* prototype) { |
| 1631 | ASSERT(!prototype->IsMap()); |
| 1632 | function->initialize_properties(); |
| 1633 | function->initialize_elements(); |
| 1634 | function->set_shared(shared); |
| 1635 | function->set_prototype_or_initial_map(prototype); |
| 1636 | function->set_context(undefined_value()); |
| 1637 | function->set_literals(empty_fixed_array()); |
| 1638 | return function; |
| 1639 | } |
| 1640 | |
| 1641 | |
| 1642 | Object* Heap::AllocateFunctionPrototype(JSFunction* function) { |
| 1643 | // Allocate the prototype. |
| 1644 | Object* prototype = |
| 1645 | AllocateJSObject(Top::context()->global_context()->object_function()); |
| 1646 | if (prototype->IsFailure()) return prototype; |
| 1647 | // When creating the prototype for the function we must set its |
| 1648 | // constructor to the function. |
| 1649 | Object* result = |
| 1650 | JSObject::cast(prototype)->SetProperty(constructor_symbol(), |
| 1651 | function, |
| 1652 | DONT_ENUM); |
| 1653 | if (result->IsFailure()) return result; |
| 1654 | return prototype; |
| 1655 | } |
| 1656 | |
| 1657 | |
| 1658 | Object* Heap::AllocateFunction(Map* function_map, |
| 1659 | SharedFunctionInfo* shared, |
| 1660 | Object* prototype) { |
| 1661 | Object* result = Allocate(function_map, OLD_SPACE); |
| 1662 | if (result->IsFailure()) return result; |
| 1663 | return InitializeFunction(JSFunction::cast(result), shared, prototype); |
| 1664 | } |
| 1665 | |
| 1666 | |
| 1667 | Object* Heap::AllocateArgumentsObject(Object* callee, int length) { |
| 1668 | // This allocation is odd since allocate an argument object |
| 1669 | // based on the arguments_boilerplate. |
| 1670 | // We do this to ensure fast allocation and map sharing. |
| 1671 | |
| 1672 | // This calls Copy directly rather than using Heap::AllocateRaw so we |
| 1673 | // duplicate the check here. |
| 1674 | ASSERT(allocation_allowed_ && gc_state_ == NOT_IN_GC); |
| 1675 | |
| 1676 | JSObject* boilerplate = |
| 1677 | Top::context()->global_context()->arguments_boilerplate(); |
| 1678 | Object* result = boilerplate->Copy(); |
| 1679 | if (result->IsFailure()) return result; |
| 1680 | |
| 1681 | Object* obj = JSObject::cast(result)->properties(); |
| 1682 | FixedArray::cast(obj)->set(arguments_callee_index, callee); |
| 1683 | FixedArray::cast(obj)->set(arguments_length_index, Smi::FromInt(length)); |
| 1684 | |
| 1685 | // Allocate the fixed array. |
| 1686 | obj = Heap::AllocateFixedArray(length); |
| 1687 | if (obj->IsFailure()) return obj; |
| 1688 | JSObject::cast(result)->set_elements(FixedArray::cast(obj)); |
| 1689 | |
| 1690 | // Check the state of the object |
| 1691 | ASSERT(JSObject::cast(result)->HasFastProperties()); |
| 1692 | ASSERT(JSObject::cast(result)->HasFastElements()); |
| 1693 | |
| 1694 | return result; |
| 1695 | } |
| 1696 | |
| 1697 | |
| 1698 | Object* Heap::AllocateInitialMap(JSFunction* fun) { |
| 1699 | ASSERT(!fun->has_initial_map()); |
| 1700 | |
| 1701 | // First create a new map. |
| 1702 | Object* map_obj = Heap::AllocateMap(JS_OBJECT_TYPE, JSObject::kHeaderSize); |
| 1703 | if (map_obj->IsFailure()) return map_obj; |
| 1704 | |
| 1705 | // Fetch or allocate prototype. |
| 1706 | Object* prototype; |
| 1707 | if (fun->has_instance_prototype()) { |
| 1708 | prototype = fun->instance_prototype(); |
| 1709 | } else { |
| 1710 | prototype = AllocateFunctionPrototype(fun); |
| 1711 | if (prototype->IsFailure()) return prototype; |
| 1712 | } |
| 1713 | Map* map = Map::cast(map_obj); |
| 1714 | map->set_unused_property_fields(fun->shared()->expected_nof_properties()); |
| 1715 | map->set_prototype(prototype); |
| 1716 | return map; |
| 1717 | } |
| 1718 | |
| 1719 | |
| 1720 | void Heap::InitializeJSObjectFromMap(JSObject* obj, |
| 1721 | FixedArray* properties, |
| 1722 | Map* map) { |
| 1723 | obj->set_properties(properties); |
| 1724 | obj->initialize_elements(); |
| 1725 | // TODO(1240798): Initialize the object's body using valid initial values |
| 1726 | // according to the object's initial map. For example, if the map's |
| 1727 | // instance type is JS_ARRAY_TYPE, the length field should be initialized |
| 1728 | // to a number (eg, Smi::FromInt(0)) and the elements initialized to a |
| 1729 | // fixed array (eg, Heap::empty_fixed_array()). Currently, the object |
| 1730 | // verification code has to cope with (temporarily) invalid objects. See |
| 1731 | // for example, JSArray::JSArrayVerify). |
| 1732 | obj->InitializeBody(map->instance_size()); |
| 1733 | } |
| 1734 | |
| 1735 | |
| 1736 | Object* Heap::AllocateJSObjectFromMap(Map* map, PretenureFlag pretenure) { |
| 1737 | // JSFunctions should be allocated using AllocateFunction to be |
| 1738 | // properly initialized. |
| 1739 | ASSERT(map->instance_type() != JS_FUNCTION_TYPE); |
| 1740 | |
| 1741 | // Allocate the backing storage for the properties. |
| 1742 | Object* properties = AllocatePropertyStorageForMap(map); |
| 1743 | if (properties->IsFailure()) return properties; |
| 1744 | |
| 1745 | // Allocate the JSObject. |
| 1746 | AllocationSpace space = (pretenure == TENURED) ? OLD_SPACE : NEW_SPACE; |
| 1747 | if (map->instance_size() > MaxHeapObjectSize()) space = LO_SPACE; |
| 1748 | Object* obj = Allocate(map, space); |
| 1749 | if (obj->IsFailure()) return obj; |
| 1750 | |
| 1751 | // Initialize the JSObject. |
| 1752 | InitializeJSObjectFromMap(JSObject::cast(obj), |
| 1753 | FixedArray::cast(properties), |
| 1754 | map); |
| 1755 | return obj; |
| 1756 | } |
| 1757 | |
| 1758 | |
| 1759 | Object* Heap::AllocateJSObject(JSFunction* constructor, |
| 1760 | PretenureFlag pretenure) { |
| 1761 | // Allocate the initial map if absent. |
| 1762 | if (!constructor->has_initial_map()) { |
| 1763 | Object* initial_map = AllocateInitialMap(constructor); |
| 1764 | if (initial_map->IsFailure()) return initial_map; |
| 1765 | constructor->set_initial_map(Map::cast(initial_map)); |
| 1766 | Map::cast(initial_map)->set_constructor(constructor); |
| 1767 | } |
| 1768 | // Allocate the object based on the constructors initial map. |
| 1769 | return AllocateJSObjectFromMap(constructor->initial_map(), pretenure); |
| 1770 | } |
| 1771 | |
| 1772 | |
| 1773 | Object* Heap::ReinitializeJSGlobalObject(JSFunction* constructor, |
| 1774 | JSGlobalObject* object) { |
| 1775 | // Allocate initial map if absent. |
| 1776 | if (!constructor->has_initial_map()) { |
| 1777 | Object* initial_map = AllocateInitialMap(constructor); |
| 1778 | if (initial_map->IsFailure()) return initial_map; |
| 1779 | constructor->set_initial_map(Map::cast(initial_map)); |
| 1780 | Map::cast(initial_map)->set_constructor(constructor); |
| 1781 | } |
| 1782 | |
| 1783 | Map* map = constructor->initial_map(); |
| 1784 | |
| 1785 | // Check that the already allocated object has the same size as |
| 1786 | // objects allocated using the constructor. |
| 1787 | ASSERT(map->instance_size() == object->map()->instance_size()); |
| 1788 | |
| 1789 | // Allocate the backing storage for the properties. |
| 1790 | Object* properties = AllocatePropertyStorageForMap(map); |
| 1791 | if (properties->IsFailure()) return properties; |
| 1792 | |
| 1793 | // Reset the map for the object. |
| 1794 | object->set_map(constructor->initial_map()); |
| 1795 | |
| 1796 | // Reinitialize the object from the constructor map. |
| 1797 | InitializeJSObjectFromMap(object, FixedArray::cast(properties), map); |
| 1798 | return object; |
| 1799 | } |
| 1800 | |
| 1801 | |
| 1802 | Object* Heap::AllocateStringFromAscii(Vector<const char> string, |
| 1803 | PretenureFlag pretenure) { |
| 1804 | Object* result = AllocateRawAsciiString(string.length(), pretenure); |
| 1805 | if (result->IsFailure()) return result; |
| 1806 | |
| 1807 | // Copy the characters into the new object. |
| 1808 | AsciiString* string_result = AsciiString::cast(result); |
| 1809 | for (int i = 0; i < string.length(); i++) { |
| 1810 | string_result->AsciiStringSet(i, string[i]); |
| 1811 | } |
| 1812 | return result; |
| 1813 | } |
| 1814 | |
| 1815 | |
| 1816 | Object* Heap::AllocateStringFromUtf8(Vector<const char> string, |
| 1817 | PretenureFlag pretenure) { |
| 1818 | // Count the number of characters in the UTF-8 string and check if |
| 1819 | // it is an ASCII string. |
| 1820 | Access<Scanner::Utf8Decoder> decoder(Scanner::utf8_decoder()); |
| 1821 | decoder->Reset(string.start(), string.length()); |
| 1822 | int chars = 0; |
| 1823 | bool is_ascii = true; |
| 1824 | while (decoder->has_more()) { |
| 1825 | uc32 r = decoder->GetNext(); |
| 1826 | if (r > String::kMaxAsciiCharCode) is_ascii = false; |
| 1827 | chars++; |
| 1828 | } |
| 1829 | |
| 1830 | // If the string is ascii, we do not need to convert the characters |
| 1831 | // since UTF8 is backwards compatible with ascii. |
| 1832 | if (is_ascii) return AllocateStringFromAscii(string, pretenure); |
| 1833 | |
| 1834 | Object* result = AllocateRawTwoByteString(chars, pretenure); |
| 1835 | if (result->IsFailure()) return result; |
| 1836 | |
| 1837 | // Convert and copy the characters into the new object. |
| 1838 | String* string_result = String::cast(result); |
| 1839 | decoder->Reset(string.start(), string.length()); |
| 1840 | for (int i = 0; i < chars; i++) { |
| 1841 | uc32 r = decoder->GetNext(); |
| 1842 | string_result->Set(i, r); |
| 1843 | } |
| 1844 | return result; |
| 1845 | } |
| 1846 | |
| 1847 | |
| 1848 | Object* Heap::AllocateStringFromTwoByte(Vector<const uc16> string, |
| 1849 | PretenureFlag pretenure) { |
| 1850 | // Check if the string is an ASCII string. |
| 1851 | int i = 0; |
| 1852 | while (i < string.length() && string[i] <= String::kMaxAsciiCharCode) i++; |
| 1853 | |
| 1854 | Object* result; |
| 1855 | if (i == string.length()) { // It's an ASCII string. |
| 1856 | result = AllocateRawAsciiString(string.length(), pretenure); |
| 1857 | } else { // It's not an ASCII string. |
| 1858 | result = AllocateRawTwoByteString(string.length(), pretenure); |
| 1859 | } |
| 1860 | if (result->IsFailure()) return result; |
| 1861 | |
| 1862 | // Copy the characters into the new object, which may be either ASCII or |
| 1863 | // UTF-16. |
| 1864 | String* string_result = String::cast(result); |
| 1865 | for (int i = 0; i < string.length(); i++) { |
| 1866 | string_result->Set(i, string[i]); |
| 1867 | } |
| 1868 | return result; |
| 1869 | } |
| 1870 | |
| 1871 | |
| 1872 | Map* Heap::SymbolMapForString(String* string) { |
| 1873 | // If the string is in new space it cannot be used as a symbol. |
| 1874 | if (InNewSpace(string)) return NULL; |
| 1875 | |
| 1876 | // Find the corresponding symbol map for strings. |
| 1877 | Map* map = string->map(); |
| 1878 | |
| 1879 | if (map == short_ascii_string_map()) return short_ascii_symbol_map(); |
| 1880 | if (map == medium_ascii_string_map()) return medium_ascii_symbol_map(); |
| 1881 | if (map == long_ascii_string_map()) return long_ascii_symbol_map(); |
| 1882 | |
| 1883 | if (map == short_string_map()) return short_symbol_map(); |
| 1884 | if (map == medium_string_map()) return medium_symbol_map(); |
| 1885 | if (map == long_string_map()) return long_symbol_map(); |
| 1886 | |
| 1887 | if (map == short_cons_string_map()) return short_cons_symbol_map(); |
| 1888 | if (map == medium_cons_string_map()) return medium_cons_symbol_map(); |
| 1889 | if (map == long_cons_string_map()) return long_cons_symbol_map(); |
| 1890 | |
| 1891 | if (map == short_cons_ascii_string_map()) { |
| 1892 | return short_cons_ascii_symbol_map(); |
| 1893 | } |
| 1894 | if (map == medium_cons_ascii_string_map()) { |
| 1895 | return medium_cons_ascii_symbol_map(); |
| 1896 | } |
| 1897 | if (map == long_cons_ascii_string_map()) { |
| 1898 | return long_cons_ascii_symbol_map(); |
| 1899 | } |
| 1900 | |
| 1901 | if (map == short_sliced_string_map()) return short_sliced_symbol_map(); |
| 1902 | if (map == medium_sliced_string_map()) return short_sliced_symbol_map(); |
| 1903 | if (map == long_sliced_string_map()) return short_sliced_symbol_map(); |
| 1904 | |
| 1905 | if (map == short_sliced_ascii_string_map()) { |
| 1906 | return short_sliced_ascii_symbol_map(); |
| 1907 | } |
| 1908 | if (map == medium_sliced_ascii_string_map()) { |
| 1909 | return short_sliced_ascii_symbol_map(); |
| 1910 | } |
| 1911 | if (map == long_sliced_ascii_string_map()) { |
| 1912 | return short_sliced_ascii_symbol_map(); |
| 1913 | } |
| 1914 | |
| 1915 | if (map == short_external_string_map()) return short_external_string_map(); |
| 1916 | if (map == medium_external_string_map()) return medium_external_string_map(); |
| 1917 | if (map == long_external_string_map()) return long_external_string_map(); |
| 1918 | |
| 1919 | if (map == short_external_ascii_string_map()) { |
| 1920 | return short_external_ascii_string_map(); |
| 1921 | } |
| 1922 | if (map == medium_external_ascii_string_map()) { |
| 1923 | return medium_external_ascii_string_map(); |
| 1924 | } |
| 1925 | if (map == long_external_ascii_string_map()) { |
| 1926 | return long_external_ascii_string_map(); |
| 1927 | } |
| 1928 | |
| 1929 | // No match found. |
| 1930 | return NULL; |
| 1931 | } |
| 1932 | |
| 1933 | |
| 1934 | Object* Heap::AllocateSymbol(unibrow::CharacterStream* buffer, |
| 1935 | int chars, |
| 1936 | int hash) { |
| 1937 | // Ensure the chars matches the number of characters in the buffer. |
| 1938 | ASSERT(static_cast<unsigned>(chars) == buffer->Length()); |
| 1939 | // Determine whether the string is ascii. |
| 1940 | bool is_ascii = true; |
| 1941 | while (buffer->has_more()) { |
| 1942 | if (buffer->GetNext() > unibrow::Utf8::kMaxOneByteChar) is_ascii = false; |
| 1943 | } |
| 1944 | buffer->Rewind(); |
| 1945 | |
| 1946 | // Compute map and object size. |
| 1947 | int size; |
| 1948 | Map* map; |
| 1949 | |
| 1950 | if (is_ascii) { |
| 1951 | if (chars <= String::kMaxShortStringSize) { |
| 1952 | map = short_ascii_symbol_map(); |
| 1953 | } else if (chars <= String::kMaxMediumStringSize) { |
| 1954 | map = medium_ascii_symbol_map(); |
| 1955 | } else { |
| 1956 | map = long_ascii_symbol_map(); |
| 1957 | } |
| 1958 | size = AsciiString::SizeFor(chars); |
| 1959 | } else { |
| 1960 | if (chars <= String::kMaxShortStringSize) { |
| 1961 | map = short_symbol_map(); |
| 1962 | } else if (chars <= String::kMaxMediumStringSize) { |
| 1963 | map = medium_symbol_map(); |
| 1964 | } else { |
| 1965 | map = long_symbol_map(); |
| 1966 | } |
| 1967 | size = TwoByteString::SizeFor(chars); |
| 1968 | } |
| 1969 | |
| 1970 | // Allocate string. |
| 1971 | AllocationSpace space = (size > MaxHeapObjectSize()) ? LO_SPACE : CODE_SPACE; |
| 1972 | Object* result = AllocateRaw(size, space); |
| 1973 | if (result->IsFailure()) return result; |
| 1974 | |
| 1975 | reinterpret_cast<HeapObject*>(result)->set_map(map); |
| 1976 | // The hash value contains the length of the string. |
| 1977 | String::cast(result)->set_length_field(hash); |
| 1978 | |
| 1979 | ASSERT_EQ(size, String::cast(result)->Size()); |
| 1980 | |
| 1981 | // Fill in the characters. |
| 1982 | for (int i = 0; i < chars; i++) { |
| 1983 | String::cast(result)->Set(i, buffer->GetNext()); |
| 1984 | } |
| 1985 | return result; |
| 1986 | } |
| 1987 | |
| 1988 | |
| 1989 | Object* Heap::AllocateRawAsciiString(int length, PretenureFlag pretenure) { |
| 1990 | AllocationSpace space = (pretenure == TENURED) ? CODE_SPACE : NEW_SPACE; |
| 1991 | int size = AsciiString::SizeFor(length); |
| 1992 | if (size > MaxHeapObjectSize()) { |
| 1993 | space = LO_SPACE; |
| 1994 | } |
| 1995 | |
| 1996 | // Use AllocateRaw rather than Allocate because the object's size cannot be |
| 1997 | // determined from the map. |
| 1998 | Object* result = AllocateRaw(size, space); |
| 1999 | if (result->IsFailure()) return result; |
| 2000 | |
| 2001 | // Determine the map based on the string's length. |
| 2002 | Map* map; |
| 2003 | if (length <= String::kMaxShortStringSize) { |
| 2004 | map = short_ascii_string_map(); |
| 2005 | } else if (length <= String::kMaxMediumStringSize) { |
| 2006 | map = medium_ascii_string_map(); |
| 2007 | } else { |
| 2008 | map = long_ascii_string_map(); |
| 2009 | } |
| 2010 | |
| 2011 | // Partially initialize the object. |
| 2012 | HeapObject::cast(result)->set_map(map); |
| 2013 | String::cast(result)->set_length(length); |
| 2014 | ASSERT_EQ(size, HeapObject::cast(result)->Size()); |
| 2015 | return result; |
| 2016 | } |
| 2017 | |
| 2018 | |
| 2019 | Object* Heap::AllocateRawTwoByteString(int length, PretenureFlag pretenure) { |
| 2020 | AllocationSpace space = (pretenure == TENURED) ? CODE_SPACE : NEW_SPACE; |
| 2021 | int size = TwoByteString::SizeFor(length); |
| 2022 | if (size > MaxHeapObjectSize()) { |
| 2023 | space = LO_SPACE; |
| 2024 | } |
| 2025 | |
| 2026 | // Use AllocateRaw rather than Allocate because the object's size cannot be |
| 2027 | // determined from the map. |
| 2028 | Object* result = AllocateRaw(size, space); |
| 2029 | if (result->IsFailure()) return result; |
| 2030 | |
| 2031 | // Determine the map based on the string's length. |
| 2032 | Map* map; |
| 2033 | if (length <= String::kMaxShortStringSize) { |
| 2034 | map = short_string_map(); |
| 2035 | } else if (length <= String::kMaxMediumStringSize) { |
| 2036 | map = medium_string_map(); |
| 2037 | } else { |
| 2038 | map = long_string_map(); |
| 2039 | } |
| 2040 | |
| 2041 | // Partially initialize the object. |
| 2042 | HeapObject::cast(result)->set_map(map); |
| 2043 | String::cast(result)->set_length(length); |
| 2044 | ASSERT_EQ(size, HeapObject::cast(result)->Size()); |
| 2045 | return result; |
| 2046 | } |
| 2047 | |
| 2048 | |
| 2049 | Object* Heap::AllocateEmptyFixedArray() { |
| 2050 | int size = FixedArray::SizeFor(0); |
| 2051 | Object* result = AllocateRaw(size, CODE_SPACE); |
| 2052 | if (result->IsFailure()) return result; |
| 2053 | // Initialize the object. |
| 2054 | reinterpret_cast<Array*>(result)->set_map(fixed_array_map()); |
| 2055 | reinterpret_cast<Array*>(result)->set_length(0); |
| 2056 | return result; |
| 2057 | } |
| 2058 | |
| 2059 | |
| 2060 | Object* Heap::AllocateFixedArray(int length, PretenureFlag pretenure) { |
| 2061 | ASSERT(empty_fixed_array()->IsFixedArray()); |
| 2062 | if (length == 0) return empty_fixed_array(); |
| 2063 | |
| 2064 | int size = FixedArray::SizeFor(length); |
| 2065 | Object* result; |
| 2066 | if (size > MaxHeapObjectSize()) { |
| 2067 | result = lo_space_->AllocateRawFixedArray(size); |
| 2068 | } else { |
| 2069 | AllocationSpace space = (pretenure == TENURED) ? OLD_SPACE : NEW_SPACE; |
| 2070 | result = AllocateRaw(size, space); |
| 2071 | } |
| 2072 | if (result->IsFailure()) return result; |
| 2073 | |
| 2074 | // Initialize the object. |
| 2075 | reinterpret_cast<Array*>(result)->set_map(fixed_array_map()); |
| 2076 | FixedArray* array = FixedArray::cast(result); |
| 2077 | array->set_length(length); |
| 2078 | for (int index = 0; index < length; index++) array->set_undefined(index); |
| 2079 | return array; |
| 2080 | } |
| 2081 | |
| 2082 | |
| 2083 | Object* Heap::AllocateFixedArrayWithHoles(int length) { |
| 2084 | if (length == 0) return empty_fixed_array(); |
| 2085 | int size = FixedArray::SizeFor(length); |
| 2086 | Object* result = size > MaxHeapObjectSize() |
| 2087 | ? lo_space_->AllocateRawFixedArray(size) |
| 2088 | : AllocateRaw(size, NEW_SPACE); |
| 2089 | if (result->IsFailure()) return result; |
| 2090 | |
| 2091 | // Initialize the object. |
| 2092 | reinterpret_cast<Array*>(result)->set_map(fixed_array_map()); |
| 2093 | FixedArray* array = FixedArray::cast(result); |
| 2094 | array->set_length(length); |
| 2095 | for (int index = 0; index < length; index++) array->set_the_hole(index); |
| 2096 | return array; |
| 2097 | } |
| 2098 | |
| 2099 | |
| 2100 | Object* Heap::AllocateHashTable(int length) { |
| 2101 | Object* result = Heap::AllocateFixedArray(length); |
| 2102 | if (result->IsFailure()) return result; |
| 2103 | reinterpret_cast<Array*>(result)->set_map(hash_table_map()); |
| 2104 | ASSERT(result->IsDictionary()); |
| 2105 | return result; |
| 2106 | } |
| 2107 | |
| 2108 | |
| 2109 | Object* Heap::AllocateGlobalContext() { |
| 2110 | Object* result = Heap::AllocateFixedArray(Context::GLOBAL_CONTEXT_SLOTS); |
| 2111 | if (result->IsFailure()) return result; |
| 2112 | Context* context = reinterpret_cast<Context*>(result); |
| 2113 | context->set_map(global_context_map()); |
| 2114 | ASSERT(context->IsGlobalContext()); |
| 2115 | ASSERT(result->IsContext()); |
| 2116 | return result; |
| 2117 | } |
| 2118 | |
| 2119 | |
| 2120 | Object* Heap::AllocateFunctionContext(int length, JSFunction* function) { |
| 2121 | ASSERT(length >= Context::MIN_CONTEXT_SLOTS); |
| 2122 | Object* result = Heap::AllocateFixedArray(length); |
| 2123 | if (result->IsFailure()) return result; |
| 2124 | Context* context = reinterpret_cast<Context*>(result); |
| 2125 | context->set_map(context_map()); |
| 2126 | context->set_closure(function); |
| 2127 | context->set_fcontext(context); |
| 2128 | context->set_previous(NULL); |
| 2129 | context->set_extension(NULL); |
| 2130 | context->set_global(function->context()->global()); |
| 2131 | ASSERT(!context->IsGlobalContext()); |
| 2132 | ASSERT(context->is_function_context()); |
| 2133 | ASSERT(result->IsContext()); |
| 2134 | return result; |
| 2135 | } |
| 2136 | |
| 2137 | |
| 2138 | Object* Heap::AllocateWithContext(Context* previous, JSObject* extension) { |
| 2139 | Object* result = Heap::AllocateFixedArray(Context::MIN_CONTEXT_SLOTS); |
| 2140 | if (result->IsFailure()) return result; |
| 2141 | Context* context = reinterpret_cast<Context*>(result); |
| 2142 | context->set_map(context_map()); |
| 2143 | context->set_closure(previous->closure()); |
| 2144 | context->set_fcontext(previous->fcontext()); |
| 2145 | context->set_previous(previous); |
| 2146 | context->set_extension(extension); |
| 2147 | context->set_global(previous->global()); |
| 2148 | ASSERT(!context->IsGlobalContext()); |
| 2149 | ASSERT(!context->is_function_context()); |
| 2150 | ASSERT(result->IsContext()); |
| 2151 | return result; |
| 2152 | } |
| 2153 | |
| 2154 | |
| 2155 | Object* Heap::AllocateStruct(InstanceType type) { |
| 2156 | Map* map; |
| 2157 | switch (type) { |
| 2158 | #define MAKE_CASE(NAME, Name, name) case NAME##_TYPE: map = name##_map(); break; |
| 2159 | STRUCT_LIST(MAKE_CASE) |
| 2160 | #undef MAKE_CASE |
| 2161 | default: |
| 2162 | UNREACHABLE(); |
| 2163 | return Failure::InternalError(); |
| 2164 | } |
| 2165 | int size = map->instance_size(); |
| 2166 | AllocationSpace space = |
| 2167 | (size > MaxHeapObjectSize()) ? LO_SPACE : OLD_SPACE; |
| 2168 | Object* result = Heap::Allocate(map, space); |
| 2169 | if (result->IsFailure()) return result; |
| 2170 | Struct::cast(result)->InitializeBody(size); |
| 2171 | return result; |
| 2172 | } |
| 2173 | |
| 2174 | |
| 2175 | #ifdef DEBUG |
| 2176 | |
| 2177 | void Heap::Print() { |
| 2178 | if (!HasBeenSetup()) return; |
| 2179 | Top::PrintStack(); |
| 2180 | new_space_->Print(); |
| 2181 | old_space_->Print(); |
| 2182 | code_space_->Print(); |
| 2183 | map_space_->Print(); |
| 2184 | lo_space_->Print(); |
| 2185 | } |
| 2186 | |
| 2187 | |
| 2188 | void Heap::ReportCodeStatistics(const char* title) { |
| 2189 | PrintF(">>>>>> Code Stats (%s) >>>>>>\n", title); |
| 2190 | PagedSpace::ResetCodeStatistics(); |
| 2191 | // We do not look for code in new space, map space, or old space. If code |
| 2192 | // somehow ends up in those spaces, we would miss it here. |
| 2193 | code_space_->CollectCodeStatistics(); |
| 2194 | lo_space_->CollectCodeStatistics(); |
| 2195 | PagedSpace::ReportCodeStatistics(); |
| 2196 | } |
| 2197 | |
| 2198 | |
| 2199 | // This function expects that NewSpace's allocated objects histogram is |
| 2200 | // populated (via a call to CollectStatistics or else as a side effect of a |
| 2201 | // just-completed scavenge collection). |
| 2202 | void Heap::ReportHeapStatistics(const char* title) { |
| 2203 | USE(title); |
| 2204 | PrintF(">>>>>> =============== %s (%d) =============== >>>>>>\n", |
| 2205 | title, gc_count_); |
| 2206 | PrintF("mark-compact GC : %d\n", mc_count_); |
| 2207 | PrintF("promoted_space_limit_ %d\n", promoted_space_limit_); |
| 2208 | |
| 2209 | PrintF("\n"); |
| 2210 | PrintF("Number of handles : %d\n", HandleScope::NumberOfHandles()); |
| 2211 | GlobalHandles::PrintStats(); |
| 2212 | PrintF("\n"); |
| 2213 | |
| 2214 | PrintF("Heap statistics : "); |
| 2215 | MemoryAllocator::ReportStatistics(); |
| 2216 | PrintF("To space : "); |
| 2217 | new_space_->ReportStatistics(); |
| 2218 | PrintF("Old space : "); |
| 2219 | old_space_->ReportStatistics(); |
| 2220 | PrintF("Code space : "); |
| 2221 | code_space_->ReportStatistics(); |
| 2222 | PrintF("Map space : "); |
| 2223 | map_space_->ReportStatistics(); |
| 2224 | PrintF("Large object space : "); |
| 2225 | lo_space_->ReportStatistics(); |
| 2226 | PrintF(">>>>>> ========================================= >>>>>>\n"); |
| 2227 | } |
| 2228 | |
| 2229 | #endif // DEBUG |
| 2230 | |
| 2231 | bool Heap::Contains(HeapObject* value) { |
| 2232 | return Contains(value->address()); |
| 2233 | } |
| 2234 | |
| 2235 | |
| 2236 | bool Heap::Contains(Address addr) { |
| 2237 | if (OS::IsOutsideAllocatedSpace(addr)) return false; |
| 2238 | return HasBeenSetup() && |
| 2239 | (new_space_->ToSpaceContains(addr) || |
| 2240 | old_space_->Contains(addr) || |
| 2241 | code_space_->Contains(addr) || |
| 2242 | map_space_->Contains(addr) || |
| 2243 | lo_space_->SlowContains(addr)); |
| 2244 | } |
| 2245 | |
| 2246 | |
| 2247 | bool Heap::InSpace(HeapObject* value, AllocationSpace space) { |
| 2248 | return InSpace(value->address(), space); |
| 2249 | } |
| 2250 | |
| 2251 | |
| 2252 | bool Heap::InSpace(Address addr, AllocationSpace space) { |
| 2253 | if (OS::IsOutsideAllocatedSpace(addr)) return false; |
| 2254 | if (!HasBeenSetup()) return false; |
| 2255 | |
| 2256 | switch (space) { |
| 2257 | case NEW_SPACE: |
| 2258 | return new_space_->ToSpaceContains(addr); |
| 2259 | case OLD_SPACE: |
| 2260 | return old_space_->Contains(addr); |
| 2261 | case CODE_SPACE: |
| 2262 | return code_space_->Contains(addr); |
| 2263 | case MAP_SPACE: |
| 2264 | return map_space_->Contains(addr); |
| 2265 | case LO_SPACE: |
| 2266 | return lo_space_->SlowContains(addr); |
| 2267 | } |
| 2268 | |
| 2269 | return false; |
| 2270 | } |
| 2271 | |
| 2272 | |
| 2273 | #ifdef DEBUG |
| 2274 | void Heap::Verify() { |
| 2275 | ASSERT(HasBeenSetup()); |
| 2276 | |
| 2277 | VerifyPointersVisitor visitor; |
| 2278 | Heap::IterateRoots(&visitor); |
| 2279 | |
| 2280 | Heap::new_space_->Verify(); |
| 2281 | Heap::old_space_->Verify(); |
| 2282 | Heap::code_space_->Verify(); |
| 2283 | Heap::map_space_->Verify(); |
| 2284 | Heap::lo_space_->Verify(); |
| 2285 | } |
| 2286 | #endif // DEBUG |
| 2287 | |
| 2288 | |
| 2289 | Object* Heap::LookupSymbol(Vector<const char> string) { |
| 2290 | Object* symbol = NULL; |
| 2291 | Object* new_table = |
| 2292 | SymbolTable::cast(symbol_table_)->LookupSymbol(string, &symbol); |
| 2293 | if (new_table->IsFailure()) return new_table; |
| 2294 | symbol_table_ = new_table; |
| 2295 | ASSERT(symbol != NULL); |
| 2296 | return symbol; |
| 2297 | } |
| 2298 | |
| 2299 | |
| 2300 | Object* Heap::LookupSymbol(String* string) { |
| 2301 | if (string->IsSymbol()) return string; |
| 2302 | Object* symbol = NULL; |
| 2303 | Object* new_table = |
| 2304 | SymbolTable::cast(symbol_table_)->LookupString(string, &symbol); |
| 2305 | if (new_table->IsFailure()) return new_table; |
| 2306 | symbol_table_ = new_table; |
| 2307 | ASSERT(symbol != NULL); |
| 2308 | return symbol; |
| 2309 | } |
| 2310 | |
| 2311 | |
| 2312 | #ifdef DEBUG |
| 2313 | void Heap::ZapFromSpace() { |
| 2314 | ASSERT(HAS_HEAP_OBJECT_TAG(kFromSpaceZapValue)); |
| 2315 | for (Address a = new_space_->FromSpaceLow(); |
| 2316 | a < new_space_->FromSpaceHigh(); |
| 2317 | a += kPointerSize) { |
| 2318 | Memory::Address_at(a) = kFromSpaceZapValue; |
| 2319 | } |
| 2320 | } |
| 2321 | #endif // DEBUG |
| 2322 | |
| 2323 | |
| 2324 | void Heap::IterateRSetRange(Address object_start, |
| 2325 | Address object_end, |
| 2326 | Address rset_start, |
| 2327 | ObjectSlotCallback copy_object_func) { |
| 2328 | Address object_address = object_start; |
| 2329 | Address rset_address = rset_start; |
| 2330 | |
| 2331 | // Loop over all the pointers in [object_start, object_end). |
| 2332 | while (object_address < object_end) { |
| 2333 | uint32_t rset_word = Memory::uint32_at(rset_address); |
| 2334 | |
| 2335 | if (rset_word != 0) { |
| 2336 | // Bits were set. |
| 2337 | uint32_t result_rset = rset_word; |
| 2338 | |
| 2339 | // Loop over all the bits in the remembered set word. Though |
| 2340 | // remembered sets are sparse, faster (eg, binary) search for |
| 2341 | // set bits does not seem to help much here. |
| 2342 | for (int bit_offset = 0; bit_offset < kBitsPerInt; bit_offset++) { |
| 2343 | uint32_t bitmask = 1 << bit_offset; |
| 2344 | // Do not dereference pointers at or past object_end. |
| 2345 | if ((rset_word & bitmask) != 0 && object_address < object_end) { |
| 2346 | Object** object_p = reinterpret_cast<Object**>(object_address); |
| 2347 | if (Heap::InFromSpace(*object_p)) { |
| 2348 | copy_object_func(reinterpret_cast<HeapObject**>(object_p)); |
| 2349 | } |
| 2350 | // If this pointer does not need to be remembered anymore, clear |
| 2351 | // the remembered set bit. |
| 2352 | if (!Heap::InToSpace(*object_p)) result_rset &= ~bitmask; |
| 2353 | } |
| 2354 | object_address += kPointerSize; |
| 2355 | } |
| 2356 | |
| 2357 | // Update the remembered set if it has changed. |
| 2358 | if (result_rset != rset_word) { |
| 2359 | Memory::uint32_at(rset_address) = result_rset; |
| 2360 | } |
| 2361 | } else { |
| 2362 | // No bits in the word were set. This is the common case. |
| 2363 | object_address += kPointerSize * kBitsPerInt; |
| 2364 | } |
| 2365 | |
| 2366 | rset_address += kIntSize; |
| 2367 | } |
| 2368 | } |
| 2369 | |
| 2370 | |
| 2371 | void Heap::IterateRSet(PagedSpace* space, ObjectSlotCallback copy_object_func) { |
| 2372 | ASSERT(Page::is_rset_in_use()); |
| 2373 | ASSERT(space == old_space_ || space == map_space_); |
| 2374 | |
| 2375 | PageIterator it(space, PageIterator::PAGES_IN_USE); |
| 2376 | while (it.has_next()) { |
| 2377 | Page* page = it.next(); |
| 2378 | IterateRSetRange(page->ObjectAreaStart(), page->AllocationTop(), |
| 2379 | page->RSetStart(), copy_object_func); |
| 2380 | } |
| 2381 | } |
| 2382 | |
| 2383 | |
| 2384 | #ifdef DEBUG |
| 2385 | #define SYNCHRONIZE_TAG(tag) v->Synchronize(tag) |
| 2386 | #else |
| 2387 | #define SYNCHRONIZE_TAG(tag) |
| 2388 | #endif |
| 2389 | |
| 2390 | void Heap::IterateRoots(ObjectVisitor* v) { |
| 2391 | IterateStrongRoots(v); |
| 2392 | v->VisitPointer(reinterpret_cast<Object**>(&symbol_table_)); |
| 2393 | SYNCHRONIZE_TAG("symbol_table"); |
| 2394 | } |
| 2395 | |
| 2396 | |
| 2397 | void Heap::IterateStrongRoots(ObjectVisitor* v) { |
| 2398 | #define ROOT_ITERATE(type, name) \ |
| 2399 | v->VisitPointer(reinterpret_cast<Object**>(&name##_)); |
| 2400 | STRONG_ROOT_LIST(ROOT_ITERATE); |
| 2401 | #undef ROOT_ITERATE |
| 2402 | SYNCHRONIZE_TAG("strong_root_list"); |
| 2403 | |
| 2404 | #define STRUCT_MAP_ITERATE(NAME, Name, name) \ |
| 2405 | v->VisitPointer(reinterpret_cast<Object**>(&name##_map_)); |
| 2406 | STRUCT_LIST(STRUCT_MAP_ITERATE); |
| 2407 | #undef STRUCT_MAP_ITERATE |
| 2408 | SYNCHRONIZE_TAG("struct_map"); |
| 2409 | |
| 2410 | #define SYMBOL_ITERATE(name, string) \ |
| 2411 | v->VisitPointer(reinterpret_cast<Object**>(&name##_)); |
| 2412 | SYMBOL_LIST(SYMBOL_ITERATE) |
| 2413 | #undef SYMBOL_ITERATE |
| 2414 | SYNCHRONIZE_TAG("symbol"); |
| 2415 | |
| 2416 | Bootstrapper::Iterate(v); |
| 2417 | SYNCHRONIZE_TAG("bootstrapper"); |
| 2418 | Top::Iterate(v); |
| 2419 | SYNCHRONIZE_TAG("top"); |
| 2420 | Debug::Iterate(v); |
| 2421 | SYNCHRONIZE_TAG("debug"); |
| 2422 | |
| 2423 | // Iterate over local handles in handle scopes. |
| 2424 | HandleScopeImplementer::Iterate(v); |
| 2425 | SYNCHRONIZE_TAG("handlescope"); |
| 2426 | |
| 2427 | // Iterate over the builtin code objects and code stubs in the heap. Note |
| 2428 | // that it is not strictly necessary to iterate over code objects on |
| 2429 | // scavenge collections. We still do it here because this same function |
| 2430 | // is used by the mark-sweep collector and the deserializer. |
| 2431 | Builtins::IterateBuiltins(v); |
| 2432 | SYNCHRONIZE_TAG("builtins"); |
| 2433 | |
| 2434 | // Iterate over global handles. |
| 2435 | GlobalHandles::IterateRoots(v); |
| 2436 | SYNCHRONIZE_TAG("globalhandles"); |
| 2437 | |
| 2438 | // Iterate over pointers being held by inactive threads. |
| 2439 | ThreadManager::Iterate(v); |
| 2440 | SYNCHRONIZE_TAG("threadmanager"); |
| 2441 | } |
| 2442 | #undef SYNCHRONIZE_TAG |
| 2443 | |
| 2444 | |
| 2445 | // Flag is set when the heap has been configured. The heap can be repeatedly |
| 2446 | // configured through the API until it is setup. |
| 2447 | static bool heap_configured = false; |
| 2448 | |
| 2449 | // TODO(1236194): Since the heap size is configurable on the command line |
| 2450 | // and through the API, we should gracefully handle the case that the heap |
| 2451 | // size is not big enough to fit all the initial objects. |
| 2452 | bool Heap::ConfigureHeap(int semispace_size, int old_gen_size) { |
| 2453 | if (HasBeenSetup()) return false; |
| 2454 | |
| 2455 | if (semispace_size > 0) semispace_size_ = semispace_size; |
| 2456 | if (old_gen_size > 0) old_generation_size_ = old_gen_size; |
| 2457 | |
| 2458 | // The new space size must be a power of two to support single-bit testing |
| 2459 | // for containment. |
| 2460 | semispace_size_ = NextPowerOf2(semispace_size_); |
| 2461 | initial_semispace_size_ = Min(initial_semispace_size_, semispace_size_); |
| 2462 | young_generation_size_ = 2 * semispace_size_; |
| 2463 | |
| 2464 | // The old generation is paged. |
| 2465 | old_generation_size_ = RoundUp(old_generation_size_, Page::kPageSize); |
| 2466 | |
| 2467 | heap_configured = true; |
| 2468 | return true; |
| 2469 | } |
| 2470 | |
| 2471 | |
| 2472 | int Heap::PromotedSpaceSize() { |
| 2473 | return old_space_->Size() |
| 2474 | + code_space_->Size() |
| 2475 | + map_space_->Size() |
| 2476 | + lo_space_->Size(); |
| 2477 | } |
| 2478 | |
| 2479 | |
| 2480 | bool Heap::Setup(bool create_heap_objects) { |
| 2481 | // Initialize heap spaces and initial maps and objects. Whenever something |
| 2482 | // goes wrong, just return false. The caller should check the results and |
| 2483 | // call Heap::TearDown() to release allocated memory. |
| 2484 | // |
| 2485 | // If the heap is not yet configured (eg, through the API), configure it. |
| 2486 | // Configuration is based on the flags new-space-size (really the semispace |
| 2487 | // size) and old-space-size if set or the initial values of semispace_size_ |
| 2488 | // and old_generation_size_ otherwise. |
| 2489 | if (!heap_configured) { |
| 2490 | if (!ConfigureHeap(FLAG_new_space_size, FLAG_old_space_size)) return false; |
| 2491 | } |
| 2492 | |
| 2493 | // Setup memory allocator and allocate an initial chunk of memory. The |
| 2494 | // initial chunk is double the size of the new space to ensure that we can |
| 2495 | // find a pair of semispaces that are contiguous and aligned to their size. |
| 2496 | if (!MemoryAllocator::Setup(MaxCapacity())) return false; |
| 2497 | void* chunk |
| 2498 | = MemoryAllocator::ReserveInitialChunk(2 * young_generation_size_); |
| 2499 | if (chunk == NULL) return false; |
| 2500 | |
| 2501 | // Put the initial chunk of the old space at the start of the initial |
| 2502 | // chunk, then the two new space semispaces, then the initial chunk of |
| 2503 | // code space. Align the pair of semispaces to their size, which must be |
| 2504 | // a power of 2. |
| 2505 | ASSERT(IsPowerOf2(young_generation_size_)); |
| 2506 | Address old_space_start = reinterpret_cast<Address>(chunk); |
| 2507 | Address new_space_start = RoundUp(old_space_start, young_generation_size_); |
| 2508 | Address code_space_start = new_space_start + young_generation_size_; |
| 2509 | int old_space_size = new_space_start - old_space_start; |
| 2510 | int code_space_size = young_generation_size_ - old_space_size; |
| 2511 | |
| 2512 | // Initialize new space. |
| 2513 | new_space_ = new NewSpace(initial_semispace_size_, semispace_size_); |
| 2514 | if (new_space_ == NULL) return false; |
| 2515 | if (!new_space_->Setup(new_space_start, young_generation_size_)) return false; |
| 2516 | |
| 2517 | // Initialize old space, set the maximum capacity to the old generation |
| 2518 | // size. |
| 2519 | old_space_ = new OldSpace(old_generation_size_, OLD_SPACE); |
| 2520 | if (old_space_ == NULL) return false; |
| 2521 | if (!old_space_->Setup(old_space_start, old_space_size)) return false; |
| 2522 | |
| 2523 | // Initialize the code space, set its maximum capacity to the old |
| 2524 | // generation size. |
| 2525 | code_space_ = new OldSpace(old_generation_size_, CODE_SPACE); |
| 2526 | if (code_space_ == NULL) return false; |
| 2527 | if (!code_space_->Setup(code_space_start, code_space_size)) return false; |
| 2528 | |
| 2529 | // Initialize map space. |
| 2530 | map_space_ = new MapSpace(kMaxMapSpaceSize); |
| 2531 | if (map_space_ == NULL) return false; |
| 2532 | // Setting up a paged space without giving it a virtual memory range big |
| 2533 | // enough to hold at least a page will cause it to allocate. |
| 2534 | if (!map_space_->Setup(NULL, 0)) return false; |
| 2535 | |
| 2536 | lo_space_ = new LargeObjectSpace(); |
| 2537 | if (lo_space_ == NULL) return false; |
| 2538 | if (!lo_space_->Setup()) return false; |
| 2539 | |
| 2540 | if (create_heap_objects) { |
| 2541 | // Create initial maps. |
| 2542 | if (!CreateInitialMaps()) return false; |
| 2543 | if (!CreateApiObjects()) return false; |
| 2544 | |
| 2545 | // Create initial objects |
| 2546 | if (!CreateInitialObjects()) return false; |
| 2547 | } |
| 2548 | |
| 2549 | LOG(IntEvent("heap-capacity", Capacity())); |
| 2550 | LOG(IntEvent("heap-available", Available())); |
| 2551 | |
| 2552 | return true; |
| 2553 | } |
| 2554 | |
| 2555 | |
| 2556 | void Heap::TearDown() { |
| 2557 | GlobalHandles::TearDown(); |
| 2558 | |
| 2559 | if (new_space_ != NULL) { |
| 2560 | new_space_->TearDown(); |
| 2561 | delete new_space_; |
| 2562 | new_space_ = NULL; |
| 2563 | } |
| 2564 | |
| 2565 | if (old_space_ != NULL) { |
| 2566 | old_space_->TearDown(); |
| 2567 | delete old_space_; |
| 2568 | old_space_ = NULL; |
| 2569 | } |
| 2570 | |
| 2571 | if (code_space_ != NULL) { |
| 2572 | code_space_->TearDown(); |
| 2573 | delete code_space_; |
| 2574 | code_space_ = NULL; |
| 2575 | } |
| 2576 | |
| 2577 | if (map_space_ != NULL) { |
| 2578 | map_space_->TearDown(); |
| 2579 | delete map_space_; |
| 2580 | map_space_ = NULL; |
| 2581 | } |
| 2582 | |
| 2583 | if (lo_space_ != NULL) { |
| 2584 | lo_space_->TearDown(); |
| 2585 | delete lo_space_; |
| 2586 | lo_space_ = NULL; |
| 2587 | } |
| 2588 | |
| 2589 | MemoryAllocator::TearDown(); |
| 2590 | } |
| 2591 | |
| 2592 | |
| 2593 | void Heap::Shrink() { |
| 2594 | // Try to shrink map, old, and code spaces. |
| 2595 | map_space_->Shrink(); |
| 2596 | old_space_->Shrink(); |
| 2597 | code_space_->Shrink(); |
| 2598 | } |
| 2599 | |
| 2600 | |
| 2601 | #ifdef DEBUG |
| 2602 | |
| 2603 | class PrintHandleVisitor: public ObjectVisitor { |
| 2604 | public: |
| 2605 | void VisitPointers(Object** start, Object** end) { |
| 2606 | for (Object** p = start; p < end; p++) |
| 2607 | PrintF(" handle %p to %p\n", p, *p); |
| 2608 | } |
| 2609 | }; |
| 2610 | |
| 2611 | void Heap::PrintHandles() { |
| 2612 | PrintF("Handles:\n"); |
| 2613 | PrintHandleVisitor v; |
| 2614 | HandleScopeImplementer::Iterate(&v); |
| 2615 | } |
| 2616 | |
| 2617 | #endif |
| 2618 | |
| 2619 | |
| 2620 | HeapIterator::HeapIterator() { |
| 2621 | Init(); |
| 2622 | } |
| 2623 | |
| 2624 | |
| 2625 | HeapIterator::~HeapIterator() { |
| 2626 | Shutdown(); |
| 2627 | } |
| 2628 | |
| 2629 | |
| 2630 | void HeapIterator::Init() { |
| 2631 | // Start the iteration. |
| 2632 | space_iterator_ = new SpaceIterator(); |
| 2633 | object_iterator_ = space_iterator_->next(); |
| 2634 | } |
| 2635 | |
| 2636 | |
| 2637 | void HeapIterator::Shutdown() { |
| 2638 | // Make sure the last iterator is deallocated. |
| 2639 | delete space_iterator_; |
| 2640 | space_iterator_ = NULL; |
| 2641 | object_iterator_ = NULL; |
| 2642 | } |
| 2643 | |
| 2644 | |
| 2645 | bool HeapIterator::has_next() { |
| 2646 | // No iterator means we are done. |
| 2647 | if (object_iterator_ == NULL) return false; |
| 2648 | |
| 2649 | if (object_iterator_->has_next_object()) { |
| 2650 | // If the current iterator has more objects we are fine. |
| 2651 | return true; |
| 2652 | } else { |
| 2653 | // Go though the spaces looking for one that has objects. |
| 2654 | while (space_iterator_->has_next()) { |
| 2655 | object_iterator_ = space_iterator_->next(); |
| 2656 | if (object_iterator_->has_next_object()) { |
| 2657 | return true; |
| 2658 | } |
| 2659 | } |
| 2660 | } |
| 2661 | // Done with the last space. |
| 2662 | object_iterator_ = NULL; |
| 2663 | return false; |
| 2664 | } |
| 2665 | |
| 2666 | |
| 2667 | HeapObject* HeapIterator::next() { |
| 2668 | if (has_next()) { |
| 2669 | return object_iterator_->next_object(); |
| 2670 | } else { |
| 2671 | return NULL; |
| 2672 | } |
| 2673 | } |
| 2674 | |
| 2675 | |
| 2676 | void HeapIterator::reset() { |
| 2677 | // Restart the iterator. |
| 2678 | Shutdown(); |
| 2679 | Init(); |
| 2680 | } |
| 2681 | |
| 2682 | |
| 2683 | // |
| 2684 | // HeapProfiler class implementation. |
| 2685 | // |
| 2686 | #ifdef ENABLE_LOGGING_AND_PROFILING |
| 2687 | void HeapProfiler::CollectStats(HeapObject* obj, HistogramInfo* info) { |
| 2688 | InstanceType type = obj->map()->instance_type(); |
| 2689 | ASSERT(0 <= type && type <= LAST_TYPE); |
| 2690 | info[type].increment_number(1); |
| 2691 | info[type].increment_bytes(obj->Size()); |
| 2692 | } |
| 2693 | #endif |
| 2694 | |
| 2695 | |
| 2696 | #ifdef ENABLE_LOGGING_AND_PROFILING |
| 2697 | void HeapProfiler::WriteSample() { |
| 2698 | LOG(HeapSampleBeginEvent("Heap", "allocated")); |
| 2699 | |
| 2700 | HistogramInfo info[LAST_TYPE+1]; |
| 2701 | #define DEF_TYPE_NAME(name) info[name].set_name(#name); |
| 2702 | INSTANCE_TYPE_LIST(DEF_TYPE_NAME) |
| 2703 | #undef DEF_TYPE_NAME |
| 2704 | |
| 2705 | HeapIterator iterator; |
| 2706 | while (iterator.has_next()) { |
| 2707 | CollectStats(iterator.next(), info); |
| 2708 | } |
| 2709 | |
| 2710 | // Lump all the string types together. |
| 2711 | int string_number = 0; |
| 2712 | int string_bytes = 0; |
| 2713 | #define INCREMENT_SIZE(type, size, name) \ |
| 2714 | string_number += info[type].number(); \ |
| 2715 | string_bytes += info[type].bytes(); |
| 2716 | STRING_TYPE_LIST(INCREMENT_SIZE) |
| 2717 | #undef INCREMENT_SIZE |
| 2718 | if (string_bytes > 0) { |
| 2719 | LOG(HeapSampleItemEvent("STRING_TYPE", string_number, string_bytes)); |
| 2720 | } |
| 2721 | |
| 2722 | for (int i = FIRST_NONSTRING_TYPE; i <= LAST_TYPE; ++i) { |
| 2723 | if (info[i].bytes() > 0) { |
| 2724 | LOG(HeapSampleItemEvent(info[i].name(), info[i].number(), |
| 2725 | info[i].bytes())); |
| 2726 | } |
| 2727 | } |
| 2728 | |
| 2729 | LOG(HeapSampleEndEvent("Heap", "allocated")); |
| 2730 | } |
| 2731 | |
| 2732 | |
| 2733 | #endif |
| 2734 | |
| 2735 | |
| 2736 | |
| 2737 | #ifdef DEBUG |
| 2738 | |
| 2739 | static bool search_for_any_global; |
| 2740 | static Object* search_target; |
| 2741 | static bool found_target; |
| 2742 | static List<Object*> object_stack(20); |
| 2743 | |
| 2744 | |
| 2745 | // Tags 0, 1, and 3 are used. Use 2 for marking visited HeapObject. |
| 2746 | static const int kMarkTag = 2; |
| 2747 | |
| 2748 | static void MarkObjectRecursively(Object** p); |
| 2749 | class MarkObjectVisitor : public ObjectVisitor { |
| 2750 | public: |
| 2751 | void VisitPointers(Object** start, Object** end) { |
| 2752 | // Copy all HeapObject pointers in [start, end) |
| 2753 | for (Object** p = start; p < end; p++) { |
| 2754 | if ((*p)->IsHeapObject()) |
| 2755 | MarkObjectRecursively(p); |
| 2756 | } |
| 2757 | } |
| 2758 | }; |
| 2759 | |
| 2760 | static MarkObjectVisitor mark_visitor; |
| 2761 | |
| 2762 | static void MarkObjectRecursively(Object** p) { |
| 2763 | if (!(*p)->IsHeapObject()) return; |
| 2764 | |
| 2765 | HeapObject* obj = HeapObject::cast(*p); |
| 2766 | |
| 2767 | Object* map = obj->map(); |
| 2768 | |
| 2769 | if (!map->IsHeapObject()) return; // visited before |
| 2770 | |
| 2771 | if (found_target) return; // stop if target found |
| 2772 | object_stack.Add(obj); |
| 2773 | if ((search_for_any_global && obj->IsJSGlobalObject()) || |
| 2774 | (!search_for_any_global && (obj == search_target))) { |
| 2775 | found_target = true; |
| 2776 | return; |
| 2777 | } |
| 2778 | |
| 2779 | if (obj->IsCode()) { |
| 2780 | Code::cast(obj)->ConvertICTargetsFromAddressToObject(); |
| 2781 | } |
| 2782 | |
| 2783 | // not visited yet |
| 2784 | Map* map_p = reinterpret_cast<Map*>(HeapObject::cast(map)); |
| 2785 | |
| 2786 | Address map_addr = map_p->address(); |
| 2787 | |
| 2788 | obj->set_map(reinterpret_cast<Map*>(map_addr + kMarkTag)); |
| 2789 | |
| 2790 | MarkObjectRecursively(&map); |
| 2791 | |
| 2792 | obj->IterateBody(map_p->instance_type(), obj->SizeFromMap(map_p), |
| 2793 | &mark_visitor); |
| 2794 | |
| 2795 | if (!found_target) // don't pop if found the target |
| 2796 | object_stack.RemoveLast(); |
| 2797 | } |
| 2798 | |
| 2799 | |
| 2800 | static void UnmarkObjectRecursively(Object** p); |
| 2801 | class UnmarkObjectVisitor : public ObjectVisitor { |
| 2802 | public: |
| 2803 | void VisitPointers(Object** start, Object** end) { |
| 2804 | // Copy all HeapObject pointers in [start, end) |
| 2805 | for (Object** p = start; p < end; p++) { |
| 2806 | if ((*p)->IsHeapObject()) |
| 2807 | UnmarkObjectRecursively(p); |
| 2808 | } |
| 2809 | } |
| 2810 | }; |
| 2811 | |
| 2812 | static UnmarkObjectVisitor unmark_visitor; |
| 2813 | |
| 2814 | static void UnmarkObjectRecursively(Object** p) { |
| 2815 | if (!(*p)->IsHeapObject()) return; |
| 2816 | |
| 2817 | HeapObject* obj = HeapObject::cast(*p); |
| 2818 | |
| 2819 | Object* map = obj->map(); |
| 2820 | |
| 2821 | if (map->IsHeapObject()) return; // unmarked already |
| 2822 | |
| 2823 | Address map_addr = reinterpret_cast<Address>(map); |
| 2824 | |
| 2825 | map_addr -= kMarkTag; |
| 2826 | |
| 2827 | ASSERT_TAG_ALIGNED(map_addr); |
| 2828 | |
| 2829 | HeapObject* map_p = HeapObject::FromAddress(map_addr); |
| 2830 | |
| 2831 | obj->set_map(reinterpret_cast<Map*>(map_p)); |
| 2832 | |
| 2833 | UnmarkObjectRecursively(reinterpret_cast<Object**>(&map_p)); |
| 2834 | |
| 2835 | obj->IterateBody(Map::cast(map_p)->instance_type(), |
| 2836 | obj->SizeFromMap(Map::cast(map_p)), |
| 2837 | &unmark_visitor); |
| 2838 | |
| 2839 | if (obj->IsCode()) { |
| 2840 | Code::cast(obj)->ConvertICTargetsFromObjectToAddress(); |
| 2841 | } |
| 2842 | } |
| 2843 | |
| 2844 | |
| 2845 | static void MarkRootObjectRecursively(Object** root) { |
| 2846 | if (search_for_any_global) { |
| 2847 | ASSERT(search_target == NULL); |
| 2848 | } else { |
| 2849 | ASSERT(search_target->IsHeapObject()); |
| 2850 | } |
| 2851 | found_target = false; |
| 2852 | object_stack.Clear(); |
| 2853 | |
| 2854 | MarkObjectRecursively(root); |
| 2855 | UnmarkObjectRecursively(root); |
| 2856 | |
| 2857 | if (found_target) { |
| 2858 | PrintF("=====================================\n"); |
| 2859 | PrintF("==== Path to object ====\n"); |
| 2860 | PrintF("=====================================\n\n"); |
| 2861 | |
| 2862 | ASSERT(!object_stack.is_empty()); |
| 2863 | for (int i = 0; i < object_stack.length(); i++) { |
| 2864 | if (i > 0) PrintF("\n |\n |\n V\n\n"); |
| 2865 | Object* obj = object_stack[i]; |
| 2866 | obj->Print(); |
| 2867 | } |
| 2868 | PrintF("=====================================\n"); |
| 2869 | } |
| 2870 | } |
| 2871 | |
| 2872 | |
| 2873 | // Helper class for visiting HeapObjects recursively. |
| 2874 | class MarkRootVisitor: public ObjectVisitor { |
| 2875 | public: |
| 2876 | void VisitPointers(Object** start, Object** end) { |
| 2877 | // Visit all HeapObject pointers in [start, end) |
| 2878 | for (Object** p = start; p < end; p++) { |
| 2879 | if ((*p)->IsHeapObject()) |
| 2880 | MarkRootObjectRecursively(p); |
| 2881 | } |
| 2882 | } |
| 2883 | }; |
| 2884 | |
| 2885 | |
| 2886 | // Triggers a depth-first traversal of reachable objects from roots |
| 2887 | // and finds a path to a specific heap object and prints it. |
| 2888 | void Heap::TracePathToObject() { |
| 2889 | search_target = NULL; |
| 2890 | search_for_any_global = false; |
| 2891 | |
| 2892 | MarkRootVisitor root_visitor; |
| 2893 | IterateRoots(&root_visitor); |
| 2894 | } |
| 2895 | |
| 2896 | |
| 2897 | // Triggers a depth-first traversal of reachable objects from roots |
| 2898 | // and finds a path to any global object and prints it. Useful for |
| 2899 | // determining the source for leaks of global objects. |
| 2900 | void Heap::TracePathToGlobal() { |
| 2901 | search_target = NULL; |
| 2902 | search_for_any_global = true; |
| 2903 | |
| 2904 | MarkRootVisitor root_visitor; |
| 2905 | IterateRoots(&root_visitor); |
| 2906 | } |
| 2907 | #endif |
| 2908 | |
| 2909 | |
| 2910 | } } // namespace v8::internal |