1 /* 2 * Copyright (C) 2013 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "rosalloc.h" 18 19 #include "base/memory_tool.h" 20 #include "base/mutex-inl.h" 21 #include "gc/space/memory_tool_settings.h" 22 #include "mem_map.h" 23 #include "mirror/class-inl.h" 24 #include "mirror/object.h" 25 #include "mirror/object-inl.h" 26 #include "thread-inl.h" 27 #include "thread_list.h" 28 29 #include <map> 30 #include <list> 31 #include <sstream> 32 #include <vector> 33 34 namespace art { 35 namespace gc { 36 namespace allocator { 37 38 static constexpr bool kUsePrefetchDuringAllocRun = false; 39 static constexpr bool kPrefetchNewRunDataByZeroing = false; 40 static constexpr size_t kPrefetchStride = 64; 41 42 size_t RosAlloc::bracketSizes[kNumOfSizeBrackets]; 43 size_t RosAlloc::numOfPages[kNumOfSizeBrackets]; 44 size_t RosAlloc::numOfSlots[kNumOfSizeBrackets]; 45 size_t RosAlloc::headerSizes[kNumOfSizeBrackets]; 46 bool RosAlloc::initialized_ = false; 47 size_t RosAlloc::dedicated_full_run_storage_[kPageSize / sizeof(size_t)] = { 0 }; 48 RosAlloc::Run* RosAlloc::dedicated_full_run_ = 49 reinterpret_cast<RosAlloc::Run*>(dedicated_full_run_storage_); 50 51 RosAlloc::RosAlloc(void* base, size_t capacity, size_t max_capacity, 52 PageReleaseMode page_release_mode, bool running_on_memory_tool, 53 size_t page_release_size_threshold) 54 : base_(reinterpret_cast<uint8_t*>(base)), footprint_(capacity), 55 capacity_(capacity), max_capacity_(max_capacity), 56 lock_("rosalloc global lock", kRosAllocGlobalLock), 57 bulk_free_lock_("rosalloc bulk free lock", kRosAllocBulkFreeLock), 58 page_release_mode_(page_release_mode), 59 page_release_size_threshold_(page_release_size_threshold), 60 is_running_on_memory_tool_(running_on_memory_tool) { 61 DCHECK_ALIGNED(base, kPageSize); 62 DCHECK_EQ(RoundUp(capacity, kPageSize), capacity); 63 DCHECK_EQ(RoundUp(max_capacity, kPageSize), max_capacity); 64 CHECK_LE(capacity, max_capacity); 65 CHECK_ALIGNED(page_release_size_threshold_, kPageSize); 66 // Zero the memory explicitly (don't rely on that the mem map is zero-initialized). 67 if (!kMadviseZeroes) { 68 memset(base_, 0, max_capacity); 69 } 70 CHECK_EQ(madvise(base_, max_capacity, MADV_DONTNEED), 0); 71 if (!initialized_) { 72 Initialize(); 73 } 74 VLOG(heap) << "RosAlloc base=" 75 << std::hex << (intptr_t)base_ << ", end=" 76 << std::hex << (intptr_t)(base_ + capacity_) 77 << ", capacity=" << std::dec << capacity_ 78 << ", max_capacity=" << std::dec << max_capacity_; 79 for (size_t i = 0; i < kNumOfSizeBrackets; i++) { 80 size_bracket_lock_names_[i] = 81 StringPrintf("an rosalloc size bracket %d lock", static_cast<int>(i)); 82 size_bracket_locks_[i] = new Mutex(size_bracket_lock_names_[i].c_str(), kRosAllocBracketLock); 83 current_runs_[i] = dedicated_full_run_; 84 } 85 DCHECK_EQ(footprint_, capacity_); 86 size_t num_of_pages = footprint_ / kPageSize; 87 size_t max_num_of_pages = max_capacity_ / kPageSize; 88 std::string error_msg; 89 page_map_mem_map_.reset(MemMap::MapAnonymous("rosalloc page map", nullptr, 90 RoundUp(max_num_of_pages, kPageSize), 91 PROT_READ | PROT_WRITE, false, false, &error_msg)); 92 CHECK(page_map_mem_map_.get() != nullptr) << "Couldn't allocate the page map : " << error_msg; 93 page_map_ = page_map_mem_map_->Begin(); 94 page_map_size_ = num_of_pages; 95 max_page_map_size_ = max_num_of_pages; 96 free_page_run_size_map_.resize(num_of_pages); 97 FreePageRun* free_pages = reinterpret_cast<FreePageRun*>(base_); 98 if (kIsDebugBuild) { 99 free_pages->magic_num_ = kMagicNumFree; 100 } 101 free_pages->SetByteSize(this, capacity_); 102 DCHECK_EQ(capacity_ % kPageSize, static_cast<size_t>(0)); 103 DCHECK(free_pages->IsFree()); 104 free_pages->ReleasePages(this); 105 DCHECK(free_pages->IsFree()); 106 free_page_runs_.insert(free_pages); 107 if (kTraceRosAlloc) { 108 LOG(INFO) << "RosAlloc::RosAlloc() : Inserted run 0x" << std::hex 109 << reinterpret_cast<intptr_t>(free_pages) 110 << " into free_page_runs_"; 111 } 112 } 113 114 RosAlloc::~RosAlloc() { 115 for (size_t i = 0; i < kNumOfSizeBrackets; i++) { 116 delete size_bracket_locks_[i]; 117 } 118 if (is_running_on_memory_tool_) { 119 MEMORY_TOOL_MAKE_DEFINED(base_, capacity_); 120 } 121 } 122 123 void* RosAlloc::AllocPages(Thread* self, size_t num_pages, uint8_t page_map_type) { 124 lock_.AssertHeld(self); 125 DCHECK(page_map_type == kPageMapRun || page_map_type == kPageMapLargeObject); 126 FreePageRun* res = nullptr; 127 const size_t req_byte_size = num_pages * kPageSize; 128 // Find the lowest address free page run that's large enough. 129 for (auto it = free_page_runs_.begin(); it != free_page_runs_.end(); ) { 130 FreePageRun* fpr = *it; 131 DCHECK(fpr->IsFree()); 132 size_t fpr_byte_size = fpr->ByteSize(this); 133 DCHECK_EQ(fpr_byte_size % kPageSize, static_cast<size_t>(0)); 134 if (req_byte_size <= fpr_byte_size) { 135 // Found one. 136 free_page_runs_.erase(it++); 137 if (kTraceRosAlloc) { 138 LOG(INFO) << "RosAlloc::AllocPages() : Erased run 0x" 139 << std::hex << reinterpret_cast<intptr_t>(fpr) 140 << " from free_page_runs_"; 141 } 142 if (req_byte_size < fpr_byte_size) { 143 // Split. 144 FreePageRun* remainder = reinterpret_cast<FreePageRun*>(reinterpret_cast<uint8_t*>(fpr) + req_byte_size); 145 if (kIsDebugBuild) { 146 remainder->magic_num_ = kMagicNumFree; 147 } 148 remainder->SetByteSize(this, fpr_byte_size - req_byte_size); 149 DCHECK_EQ(remainder->ByteSize(this) % kPageSize, static_cast<size_t>(0)); 150 // Don't need to call madvise on remainder here. 151 free_page_runs_.insert(remainder); 152 if (kTraceRosAlloc) { 153 LOG(INFO) << "RosAlloc::AllocPages() : Inserted run 0x" << std::hex 154 << reinterpret_cast<intptr_t>(remainder) 155 << " into free_page_runs_"; 156 } 157 fpr->SetByteSize(this, req_byte_size); 158 DCHECK_EQ(fpr->ByteSize(this) % kPageSize, static_cast<size_t>(0)); 159 } 160 res = fpr; 161 break; 162 } else { 163 ++it; 164 } 165 } 166 167 // Failed to allocate pages. Grow the footprint, if possible. 168 if (UNLIKELY(res == nullptr && capacity_ > footprint_)) { 169 FreePageRun* last_free_page_run = nullptr; 170 size_t last_free_page_run_size; 171 auto it = free_page_runs_.rbegin(); 172 if (it != free_page_runs_.rend() && (last_free_page_run = *it)->End(this) == base_ + footprint_) { 173 // There is a free page run at the end. 174 DCHECK(last_free_page_run->IsFree()); 175 DCHECK(IsFreePage(ToPageMapIndex(last_free_page_run))); 176 last_free_page_run_size = last_free_page_run->ByteSize(this); 177 } else { 178 // There is no free page run at the end. 179 last_free_page_run_size = 0; 180 } 181 DCHECK_LT(last_free_page_run_size, req_byte_size); 182 if (capacity_ - footprint_ + last_free_page_run_size >= req_byte_size) { 183 // If we grow the heap, we can allocate it. 184 size_t increment = std::min(std::max(2 * MB, req_byte_size - last_free_page_run_size), 185 capacity_ - footprint_); 186 DCHECK_EQ(increment % kPageSize, static_cast<size_t>(0)); 187 size_t new_footprint = footprint_ + increment; 188 size_t new_num_of_pages = new_footprint / kPageSize; 189 DCHECK_LT(page_map_size_, new_num_of_pages); 190 DCHECK_LT(free_page_run_size_map_.size(), new_num_of_pages); 191 page_map_size_ = new_num_of_pages; 192 DCHECK_LE(page_map_size_, max_page_map_size_); 193 free_page_run_size_map_.resize(new_num_of_pages); 194 ArtRosAllocMoreCore(this, increment); 195 if (last_free_page_run_size > 0) { 196 // There was a free page run at the end. Expand its size. 197 DCHECK_EQ(last_free_page_run_size, last_free_page_run->ByteSize(this)); 198 last_free_page_run->SetByteSize(this, last_free_page_run_size + increment); 199 DCHECK_EQ(last_free_page_run->ByteSize(this) % kPageSize, static_cast<size_t>(0)); 200 DCHECK_EQ(last_free_page_run->End(this), base_ + new_footprint); 201 } else { 202 // Otherwise, insert a new free page run at the end. 203 FreePageRun* new_free_page_run = reinterpret_cast<FreePageRun*>(base_ + footprint_); 204 if (kIsDebugBuild) { 205 new_free_page_run->magic_num_ = kMagicNumFree; 206 } 207 new_free_page_run->SetByteSize(this, increment); 208 DCHECK_EQ(new_free_page_run->ByteSize(this) % kPageSize, static_cast<size_t>(0)); 209 free_page_runs_.insert(new_free_page_run); 210 DCHECK_EQ(*free_page_runs_.rbegin(), new_free_page_run); 211 if (kTraceRosAlloc) { 212 LOG(INFO) << "RosAlloc::AlloPages() : Grew the heap by inserting run 0x" 213 << std::hex << reinterpret_cast<intptr_t>(new_free_page_run) 214 << " into free_page_runs_"; 215 } 216 } 217 DCHECK_LE(footprint_ + increment, capacity_); 218 if (kTraceRosAlloc) { 219 LOG(INFO) << "RosAlloc::AllocPages() : increased the footprint from " 220 << footprint_ << " to " << new_footprint; 221 } 222 footprint_ = new_footprint; 223 224 // And retry the last free page run. 225 it = free_page_runs_.rbegin(); 226 DCHECK(it != free_page_runs_.rend()); 227 FreePageRun* fpr = *it; 228 if (kIsDebugBuild && last_free_page_run_size > 0) { 229 DCHECK(last_free_page_run != nullptr); 230 DCHECK_EQ(last_free_page_run, fpr); 231 } 232 size_t fpr_byte_size = fpr->ByteSize(this); 233 DCHECK_EQ(fpr_byte_size % kPageSize, static_cast<size_t>(0)); 234 DCHECK_LE(req_byte_size, fpr_byte_size); 235 free_page_runs_.erase(fpr); 236 if (kTraceRosAlloc) { 237 LOG(INFO) << "RosAlloc::AllocPages() : Erased run 0x" << std::hex << reinterpret_cast<intptr_t>(fpr) 238 << " from free_page_runs_"; 239 } 240 if (req_byte_size < fpr_byte_size) { 241 // Split if there's a remainder. 242 FreePageRun* remainder = reinterpret_cast<FreePageRun*>(reinterpret_cast<uint8_t*>(fpr) + req_byte_size); 243 if (kIsDebugBuild) { 244 remainder->magic_num_ = kMagicNumFree; 245 } 246 remainder->SetByteSize(this, fpr_byte_size - req_byte_size); 247 DCHECK_EQ(remainder->ByteSize(this) % kPageSize, static_cast<size_t>(0)); 248 free_page_runs_.insert(remainder); 249 if (kTraceRosAlloc) { 250 LOG(INFO) << "RosAlloc::AllocPages() : Inserted run 0x" << std::hex 251 << reinterpret_cast<intptr_t>(remainder) 252 << " into free_page_runs_"; 253 } 254 fpr->SetByteSize(this, req_byte_size); 255 DCHECK_EQ(fpr->ByteSize(this) % kPageSize, static_cast<size_t>(0)); 256 } 257 res = fpr; 258 } 259 } 260 if (LIKELY(res != nullptr)) { 261 // Update the page map. 262 size_t page_map_idx = ToPageMapIndex(res); 263 for (size_t i = 0; i < num_pages; i++) { 264 DCHECK(IsFreePage(page_map_idx + i)); 265 } 266 switch (page_map_type) { 267 case kPageMapRun: 268 page_map_[page_map_idx] = kPageMapRun; 269 for (size_t i = 1; i < num_pages; i++) { 270 page_map_[page_map_idx + i] = kPageMapRunPart; 271 } 272 break; 273 case kPageMapLargeObject: 274 page_map_[page_map_idx] = kPageMapLargeObject; 275 for (size_t i = 1; i < num_pages; i++) { 276 page_map_[page_map_idx + i] = kPageMapLargeObjectPart; 277 } 278 break; 279 default: 280 LOG(FATAL) << "Unreachable - page map type: " << static_cast<int>(page_map_type); 281 break; 282 } 283 if (kIsDebugBuild) { 284 // Clear the first page since it is not madvised due to the magic number. 285 memset(res, 0, kPageSize); 286 } 287 if (kTraceRosAlloc) { 288 LOG(INFO) << "RosAlloc::AllocPages() : 0x" << std::hex << reinterpret_cast<intptr_t>(res) 289 << "-0x" << (reinterpret_cast<intptr_t>(res) + num_pages * kPageSize) 290 << "(" << std::dec << (num_pages * kPageSize) << ")"; 291 } 292 return res; 293 } 294 295 // Fail. 296 if (kTraceRosAlloc) { 297 LOG(INFO) << "RosAlloc::AllocPages() : nullptr"; 298 } 299 return nullptr; 300 } 301 302 size_t RosAlloc::FreePages(Thread* self, void* ptr, bool already_zero) { 303 lock_.AssertHeld(self); 304 size_t pm_idx = ToPageMapIndex(ptr); 305 DCHECK_LT(pm_idx, page_map_size_); 306 uint8_t pm_type = page_map_[pm_idx]; 307 DCHECK(pm_type == kPageMapRun || pm_type == kPageMapLargeObject); 308 uint8_t pm_part_type; 309 switch (pm_type) { 310 case kPageMapRun: 311 pm_part_type = kPageMapRunPart; 312 break; 313 case kPageMapLargeObject: 314 pm_part_type = kPageMapLargeObjectPart; 315 break; 316 default: 317 LOG(FATAL) << "Unreachable - " << __PRETTY_FUNCTION__ << " : " << "pm_idx=" << pm_idx << ", pm_type=" 318 << static_cast<int>(pm_type) << ", ptr=" << std::hex 319 << reinterpret_cast<intptr_t>(ptr); 320 return 0; 321 } 322 // Update the page map and count the number of pages. 323 size_t num_pages = 1; 324 page_map_[pm_idx] = kPageMapEmpty; 325 size_t idx = pm_idx + 1; 326 size_t end = page_map_size_; 327 while (idx < end && page_map_[idx] == pm_part_type) { 328 page_map_[idx] = kPageMapEmpty; 329 num_pages++; 330 idx++; 331 } 332 const size_t byte_size = num_pages * kPageSize; 333 if (already_zero) { 334 if (ShouldCheckZeroMemory()) { 335 const uintptr_t* word_ptr = reinterpret_cast<uintptr_t*>(ptr); 336 for (size_t i = 0; i < byte_size / sizeof(uintptr_t); ++i) { 337 CHECK_EQ(word_ptr[i], 0U) << "words don't match at index " << i; 338 } 339 } 340 } else if (!DoesReleaseAllPages()) { 341 memset(ptr, 0, byte_size); 342 } 343 344 if (kTraceRosAlloc) { 345 LOG(INFO) << __PRETTY_FUNCTION__ << " : 0x" << std::hex << reinterpret_cast<intptr_t>(ptr) 346 << "-0x" << (reinterpret_cast<intptr_t>(ptr) + byte_size) 347 << "(" << std::dec << (num_pages * kPageSize) << ")"; 348 } 349 350 // Turn it into a free run. 351 FreePageRun* fpr = reinterpret_cast<FreePageRun*>(ptr); 352 if (kIsDebugBuild) { 353 fpr->magic_num_ = kMagicNumFree; 354 } 355 fpr->SetByteSize(this, byte_size); 356 DCHECK_ALIGNED(fpr->ByteSize(this), kPageSize); 357 358 DCHECK(free_page_runs_.find(fpr) == free_page_runs_.end()); 359 if (!free_page_runs_.empty()) { 360 // Try to coalesce in the higher address direction. 361 if (kTraceRosAlloc) { 362 LOG(INFO) << __PRETTY_FUNCTION__ << "RosAlloc::FreePages() : trying to coalesce a free page run 0x" 363 << std::hex << reinterpret_cast<uintptr_t>(fpr) << " [" << std::dec << pm_idx << "] -0x" 364 << std::hex << reinterpret_cast<uintptr_t>(fpr->End(this)) << " [" << std::dec 365 << (fpr->End(this) == End() ? page_map_size_ : ToPageMapIndex(fpr->End(this))) << "]"; 366 } 367 auto higher_it = free_page_runs_.upper_bound(fpr); 368 if (higher_it != free_page_runs_.end()) { 369 for (auto it = higher_it; it != free_page_runs_.end(); ) { 370 FreePageRun* h = *it; 371 DCHECK_EQ(h->ByteSize(this) % kPageSize, static_cast<size_t>(0)); 372 if (kTraceRosAlloc) { 373 LOG(INFO) << "RosAlloc::FreePages() : trying to coalesce with a higher free page run 0x" 374 << std::hex << reinterpret_cast<uintptr_t>(h) << " [" << std::dec << ToPageMapIndex(h) << "] -0x" 375 << std::hex << reinterpret_cast<uintptr_t>(h->End(this)) << " [" << std::dec 376 << (h->End(this) == End() ? page_map_size_ : ToPageMapIndex(h->End(this))) << "]"; 377 } 378 if (fpr->End(this) == h->Begin()) { 379 if (kTraceRosAlloc) { 380 LOG(INFO) << "Success"; 381 } 382 // Clear magic num since this is no longer the start of a free page run. 383 if (kIsDebugBuild) { 384 h->magic_num_ = 0; 385 } 386 free_page_runs_.erase(it++); 387 if (kTraceRosAlloc) { 388 LOG(INFO) << "RosAlloc::FreePages() : (coalesce) Erased run 0x" << std::hex 389 << reinterpret_cast<intptr_t>(h) 390 << " from free_page_runs_"; 391 } 392 fpr->SetByteSize(this, fpr->ByteSize(this) + h->ByteSize(this)); 393 DCHECK_EQ(fpr->ByteSize(this) % kPageSize, static_cast<size_t>(0)); 394 } else { 395 // Not adjacent. Stop. 396 if (kTraceRosAlloc) { 397 LOG(INFO) << "Fail"; 398 } 399 break; 400 } 401 } 402 } 403 // Try to coalesce in the lower address direction. 404 auto lower_it = free_page_runs_.upper_bound(fpr); 405 if (lower_it != free_page_runs_.begin()) { 406 --lower_it; 407 for (auto it = lower_it; ; ) { 408 // We want to try to coalesce with the first element but 409 // there's no "<=" operator for the iterator. 410 bool to_exit_loop = it == free_page_runs_.begin(); 411 412 FreePageRun* l = *it; 413 DCHECK_EQ(l->ByteSize(this) % kPageSize, static_cast<size_t>(0)); 414 if (kTraceRosAlloc) { 415 LOG(INFO) << "RosAlloc::FreePages() : trying to coalesce with a lower free page run 0x" 416 << std::hex << reinterpret_cast<uintptr_t>(l) << " [" << std::dec << ToPageMapIndex(l) << "] -0x" 417 << std::hex << reinterpret_cast<uintptr_t>(l->End(this)) << " [" << std::dec 418 << (l->End(this) == End() ? page_map_size_ : ToPageMapIndex(l->End(this))) << "]"; 419 } 420 if (l->End(this) == fpr->Begin()) { 421 if (kTraceRosAlloc) { 422 LOG(INFO) << "Success"; 423 } 424 free_page_runs_.erase(it--); 425 if (kTraceRosAlloc) { 426 LOG(INFO) << "RosAlloc::FreePages() : (coalesce) Erased run 0x" << std::hex 427 << reinterpret_cast<intptr_t>(l) 428 << " from free_page_runs_"; 429 } 430 l->SetByteSize(this, l->ByteSize(this) + fpr->ByteSize(this)); 431 DCHECK_EQ(l->ByteSize(this) % kPageSize, static_cast<size_t>(0)); 432 // Clear magic num since this is no longer the start of a free page run. 433 if (kIsDebugBuild) { 434 fpr->magic_num_ = 0; 435 } 436 fpr = l; 437 } else { 438 // Not adjacent. Stop. 439 if (kTraceRosAlloc) { 440 LOG(INFO) << "Fail"; 441 } 442 break; 443 } 444 if (to_exit_loop) { 445 break; 446 } 447 } 448 } 449 } 450 451 // Insert it. 452 DCHECK_EQ(fpr->ByteSize(this) % kPageSize, static_cast<size_t>(0)); 453 DCHECK(free_page_runs_.find(fpr) == free_page_runs_.end()); 454 DCHECK(fpr->IsFree()); 455 fpr->ReleasePages(this); 456 DCHECK(fpr->IsFree()); 457 free_page_runs_.insert(fpr); 458 DCHECK(free_page_runs_.find(fpr) != free_page_runs_.end()); 459 if (kTraceRosAlloc) { 460 LOG(INFO) << "RosAlloc::FreePages() : Inserted run 0x" << std::hex << reinterpret_cast<intptr_t>(fpr) 461 << " into free_page_runs_"; 462 } 463 return byte_size; 464 } 465 466 void* RosAlloc::AllocLargeObject(Thread* self, size_t size, size_t* bytes_allocated, 467 size_t* usable_size, size_t* bytes_tl_bulk_allocated) { 468 DCHECK(bytes_allocated != nullptr); 469 DCHECK(usable_size != nullptr); 470 DCHECK_GT(size, kLargeSizeThreshold); 471 size_t num_pages = RoundUp(size, kPageSize) / kPageSize; 472 void* r; 473 { 474 MutexLock mu(self, lock_); 475 r = AllocPages(self, num_pages, kPageMapLargeObject); 476 } 477 if (UNLIKELY(r == nullptr)) { 478 if (kTraceRosAlloc) { 479 LOG(INFO) << "RosAlloc::AllocLargeObject() : nullptr"; 480 } 481 return nullptr; 482 } 483 const size_t total_bytes = num_pages * kPageSize; 484 *bytes_allocated = total_bytes; 485 *usable_size = total_bytes; 486 *bytes_tl_bulk_allocated = total_bytes; 487 if (kTraceRosAlloc) { 488 LOG(INFO) << "RosAlloc::AllocLargeObject() : 0x" << std::hex << reinterpret_cast<intptr_t>(r) 489 << "-0x" << (reinterpret_cast<intptr_t>(r) + num_pages * kPageSize) 490 << "(" << std::dec << (num_pages * kPageSize) << ")"; 491 } 492 // Check if the returned memory is really all zero. 493 if (ShouldCheckZeroMemory()) { 494 CHECK_EQ(total_bytes % sizeof(uintptr_t), 0U); 495 const uintptr_t* words = reinterpret_cast<uintptr_t*>(r); 496 for (size_t i = 0; i < total_bytes / sizeof(uintptr_t); ++i) { 497 CHECK_EQ(words[i], 0U); 498 } 499 } 500 return r; 501 } 502 503 size_t RosAlloc::FreeInternal(Thread* self, void* ptr) { 504 DCHECK_LE(base_, ptr); 505 DCHECK_LT(ptr, base_ + footprint_); 506 size_t pm_idx = RoundDownToPageMapIndex(ptr); 507 Run* run = nullptr; 508 { 509 MutexLock mu(self, lock_); 510 DCHECK_LT(pm_idx, page_map_size_); 511 uint8_t page_map_entry = page_map_[pm_idx]; 512 if (kTraceRosAlloc) { 513 LOG(INFO) << "RosAlloc::FreeInternal() : " << std::hex << ptr << ", pm_idx=" << std::dec << pm_idx 514 << ", page_map_entry=" << static_cast<int>(page_map_entry); 515 } 516 switch (page_map_[pm_idx]) { 517 case kPageMapLargeObject: 518 return FreePages(self, ptr, false); 519 case kPageMapLargeObjectPart: 520 LOG(FATAL) << "Unreachable - page map type: " << static_cast<int>(page_map_[pm_idx]); 521 return 0; 522 case kPageMapRunPart: { 523 // Find the beginning of the run. 524 do { 525 --pm_idx; 526 DCHECK_LT(pm_idx, capacity_ / kPageSize); 527 } while (page_map_[pm_idx] != kPageMapRun); 528 FALLTHROUGH_INTENDED; 529 case kPageMapRun: 530 run = reinterpret_cast<Run*>(base_ + pm_idx * kPageSize); 531 DCHECK_EQ(run->magic_num_, kMagicNum); 532 break; 533 case kPageMapReleased: 534 case kPageMapEmpty: 535 LOG(FATAL) << "Unreachable - page map type: " << static_cast<int>(page_map_[pm_idx]); 536 return 0; 537 } 538 default: 539 LOG(FATAL) << "Unreachable - page map type: " << static_cast<int>(page_map_[pm_idx]); 540 return 0; 541 } 542 } 543 DCHECK(run != nullptr); 544 return FreeFromRun(self, ptr, run); 545 } 546 547 size_t RosAlloc::Free(Thread* self, void* ptr) { 548 ReaderMutexLock rmu(self, bulk_free_lock_); 549 return FreeInternal(self, ptr); 550 } 551 552 RosAlloc::Run* RosAlloc::AllocRun(Thread* self, size_t idx) { 553 RosAlloc::Run* new_run = nullptr; 554 { 555 MutexLock mu(self, lock_); 556 new_run = reinterpret_cast<Run*>(AllocPages(self, numOfPages[idx], kPageMapRun)); 557 } 558 if (LIKELY(new_run != nullptr)) { 559 if (kIsDebugBuild) { 560 new_run->magic_num_ = kMagicNum; 561 } 562 new_run->size_bracket_idx_ = idx; 563 DCHECK(!new_run->IsThreadLocal()); 564 DCHECK(!new_run->to_be_bulk_freed_); 565 if (kUsePrefetchDuringAllocRun && idx < kNumThreadLocalSizeBrackets) { 566 // Take ownership of the cache lines if we are likely to be thread local run. 567 if (kPrefetchNewRunDataByZeroing) { 568 // Zeroing the data is sometimes faster than prefetching but it increases memory usage 569 // since we end up dirtying zero pages which may have been madvised. 570 new_run->ZeroData(); 571 } else { 572 const size_t num_of_slots = numOfSlots[idx]; 573 const size_t bracket_size = bracketSizes[idx]; 574 const size_t num_of_bytes = num_of_slots * bracket_size; 575 uint8_t* begin = reinterpret_cast<uint8_t*>(new_run) + headerSizes[idx]; 576 for (size_t i = 0; i < num_of_bytes; i += kPrefetchStride) { 577 __builtin_prefetch(begin + i); 578 } 579 } 580 } 581 new_run->InitFreeList(); 582 } 583 return new_run; 584 } 585 586 RosAlloc::Run* RosAlloc::RefillRun(Thread* self, size_t idx) { 587 // Get the lowest address non-full run from the binary tree. 588 auto* const bt = &non_full_runs_[idx]; 589 if (!bt->empty()) { 590 // If there's one, use it as the current run. 591 auto it = bt->begin(); 592 Run* non_full_run = *it; 593 DCHECK(non_full_run != nullptr); 594 DCHECK(!non_full_run->IsThreadLocal()); 595 bt->erase(it); 596 return non_full_run; 597 } 598 // If there's none, allocate a new run and use it as the current run. 599 return AllocRun(self, idx); 600 } 601 602 inline void* RosAlloc::AllocFromCurrentRunUnlocked(Thread* self, size_t idx) { 603 Run* current_run = current_runs_[idx]; 604 DCHECK(current_run != nullptr); 605 void* slot_addr = current_run->AllocSlot(); 606 if (UNLIKELY(slot_addr == nullptr)) { 607 // The current run got full. Try to refill it. 608 DCHECK(current_run->IsFull()); 609 if (kIsDebugBuild && current_run != dedicated_full_run_) { 610 full_runs_[idx].insert(current_run); 611 if (kTraceRosAlloc) { 612 LOG(INFO) << __PRETTY_FUNCTION__ << " : Inserted run 0x" << std::hex 613 << reinterpret_cast<intptr_t>(current_run) 614 << " into full_runs_[" << std::dec << idx << "]"; 615 } 616 DCHECK(non_full_runs_[idx].find(current_run) == non_full_runs_[idx].end()); 617 DCHECK(full_runs_[idx].find(current_run) != full_runs_[idx].end()); 618 } 619 current_run = RefillRun(self, idx); 620 if (UNLIKELY(current_run == nullptr)) { 621 // Failed to allocate a new run, make sure that it is the dedicated full run. 622 current_runs_[idx] = dedicated_full_run_; 623 return nullptr; 624 } 625 DCHECK(current_run != nullptr); 626 DCHECK(non_full_runs_[idx].find(current_run) == non_full_runs_[idx].end()); 627 DCHECK(full_runs_[idx].find(current_run) == full_runs_[idx].end()); 628 current_run->SetIsThreadLocal(false); 629 current_runs_[idx] = current_run; 630 DCHECK(!current_run->IsFull()); 631 slot_addr = current_run->AllocSlot(); 632 // Must succeed now with a new run. 633 DCHECK(slot_addr != nullptr); 634 } 635 return slot_addr; 636 } 637 638 void* RosAlloc::AllocFromRunThreadUnsafe(Thread* self, size_t size, size_t* bytes_allocated, 639 size_t* usable_size, 640 size_t* bytes_tl_bulk_allocated) { 641 DCHECK(bytes_allocated != nullptr); 642 DCHECK(usable_size != nullptr); 643 DCHECK(bytes_tl_bulk_allocated != nullptr); 644 DCHECK_LE(size, kLargeSizeThreshold); 645 size_t bracket_size; 646 size_t idx = SizeToIndexAndBracketSize(size, &bracket_size); 647 Locks::mutator_lock_->AssertExclusiveHeld(self); 648 void* slot_addr = AllocFromCurrentRunUnlocked(self, idx); 649 if (LIKELY(slot_addr != nullptr)) { 650 *bytes_allocated = bracket_size; 651 *usable_size = bracket_size; 652 *bytes_tl_bulk_allocated = bracket_size; 653 } 654 // Caller verifies that it is all 0. 655 return slot_addr; 656 } 657 658 void* RosAlloc::AllocFromRun(Thread* self, size_t size, size_t* bytes_allocated, 659 size_t* usable_size, size_t* bytes_tl_bulk_allocated) { 660 DCHECK(bytes_allocated != nullptr); 661 DCHECK(usable_size != nullptr); 662 DCHECK(bytes_tl_bulk_allocated != nullptr); 663 DCHECK_LE(size, kLargeSizeThreshold); 664 size_t bracket_size; 665 size_t idx = SizeToIndexAndBracketSize(size, &bracket_size); 666 void* slot_addr; 667 if (LIKELY(idx < kNumThreadLocalSizeBrackets)) { 668 // Use a thread-local run. 669 Run* thread_local_run = reinterpret_cast<Run*>(self->GetRosAllocRun(idx)); 670 // Allow invalid since this will always fail the allocation. 671 if (kIsDebugBuild) { 672 // Need the lock to prevent race conditions. 673 MutexLock mu(self, *size_bracket_locks_[idx]); 674 CHECK(non_full_runs_[idx].find(thread_local_run) == non_full_runs_[idx].end()); 675 CHECK(full_runs_[idx].find(thread_local_run) == full_runs_[idx].end()); 676 } 677 DCHECK(thread_local_run != nullptr); 678 DCHECK(thread_local_run->IsThreadLocal() || thread_local_run == dedicated_full_run_); 679 slot_addr = thread_local_run->AllocSlot(); 680 // The allocation must fail if the run is invalid. 681 DCHECK(thread_local_run != dedicated_full_run_ || slot_addr == nullptr) 682 << "allocated from an invalid run"; 683 if (UNLIKELY(slot_addr == nullptr)) { 684 // The run got full. Try to free slots. 685 DCHECK(thread_local_run->IsFull()); 686 MutexLock mu(self, *size_bracket_locks_[idx]); 687 bool is_all_free_after_merge; 688 // This is safe to do for the dedicated_full_run_ since the bitmaps are empty. 689 if (thread_local_run->MergeThreadLocalFreeListToFreeList(&is_all_free_after_merge)) { 690 DCHECK_NE(thread_local_run, dedicated_full_run_); 691 // Some slot got freed. Keep it. 692 DCHECK(!thread_local_run->IsFull()); 693 DCHECK_EQ(is_all_free_after_merge, thread_local_run->IsAllFree()); 694 } else { 695 // No slots got freed. Try to refill the thread-local run. 696 DCHECK(thread_local_run->IsFull()); 697 if (thread_local_run != dedicated_full_run_) { 698 thread_local_run->SetIsThreadLocal(false); 699 if (kIsDebugBuild) { 700 full_runs_[idx].insert(thread_local_run); 701 if (kTraceRosAlloc) { 702 LOG(INFO) << "RosAlloc::AllocFromRun() : Inserted run 0x" << std::hex 703 << reinterpret_cast<intptr_t>(thread_local_run) 704 << " into full_runs_[" << std::dec << idx << "]"; 705 } 706 } 707 DCHECK(non_full_runs_[idx].find(thread_local_run) == non_full_runs_[idx].end()); 708 DCHECK(full_runs_[idx].find(thread_local_run) != full_runs_[idx].end()); 709 } 710 711 thread_local_run = RefillRun(self, idx); 712 if (UNLIKELY(thread_local_run == nullptr)) { 713 self->SetRosAllocRun(idx, dedicated_full_run_); 714 return nullptr; 715 } 716 DCHECK(non_full_runs_[idx].find(thread_local_run) == non_full_runs_[idx].end()); 717 DCHECK(full_runs_[idx].find(thread_local_run) == full_runs_[idx].end()); 718 thread_local_run->SetIsThreadLocal(true); 719 self->SetRosAllocRun(idx, thread_local_run); 720 DCHECK(!thread_local_run->IsFull()); 721 } 722 DCHECK(thread_local_run != nullptr); 723 DCHECK(!thread_local_run->IsFull()); 724 DCHECK(thread_local_run->IsThreadLocal()); 725 // Account for all the free slots in the new or refreshed thread local run. 726 *bytes_tl_bulk_allocated = thread_local_run->NumberOfFreeSlots() * bracket_size; 727 slot_addr = thread_local_run->AllocSlot(); 728 // Must succeed now with a new run. 729 DCHECK(slot_addr != nullptr); 730 } else { 731 // The slot is already counted. Leave it as is. 732 *bytes_tl_bulk_allocated = 0; 733 } 734 DCHECK(slot_addr != nullptr); 735 if (kTraceRosAlloc) { 736 LOG(INFO) << "RosAlloc::AllocFromRun() thread-local : 0x" << std::hex 737 << reinterpret_cast<intptr_t>(slot_addr) 738 << "-0x" << (reinterpret_cast<intptr_t>(slot_addr) + bracket_size) 739 << "(" << std::dec << (bracket_size) << ")"; 740 } 741 *bytes_allocated = bracket_size; 742 *usable_size = bracket_size; 743 } else { 744 // Use the (shared) current run. 745 MutexLock mu(self, *size_bracket_locks_[idx]); 746 slot_addr = AllocFromCurrentRunUnlocked(self, idx); 747 if (kTraceRosAlloc) { 748 LOG(INFO) << "RosAlloc::AllocFromRun() : 0x" << std::hex 749 << reinterpret_cast<intptr_t>(slot_addr) 750 << "-0x" << (reinterpret_cast<intptr_t>(slot_addr) + bracket_size) 751 << "(" << std::dec << (bracket_size) << ")"; 752 } 753 if (LIKELY(slot_addr != nullptr)) { 754 *bytes_allocated = bracket_size; 755 *usable_size = bracket_size; 756 *bytes_tl_bulk_allocated = bracket_size; 757 } 758 } 759 // Caller verifies that it is all 0. 760 return slot_addr; 761 } 762 763 size_t RosAlloc::FreeFromRun(Thread* self, void* ptr, Run* run) { 764 DCHECK_EQ(run->magic_num_, kMagicNum); 765 DCHECK_LT(run, ptr); 766 DCHECK_LT(ptr, run->End()); 767 const size_t idx = run->size_bracket_idx_; 768 const size_t bracket_size = bracketSizes[idx]; 769 bool run_was_full = false; 770 MutexLock brackets_mu(self, *size_bracket_locks_[idx]); 771 if (kIsDebugBuild) { 772 run_was_full = run->IsFull(); 773 } 774 if (kTraceRosAlloc) { 775 LOG(INFO) << "RosAlloc::FreeFromRun() : 0x" << std::hex << reinterpret_cast<intptr_t>(ptr); 776 } 777 if (LIKELY(run->IsThreadLocal())) { 778 // It's a thread-local run. Just mark the thread-local free bit map and return. 779 DCHECK_LT(run->size_bracket_idx_, kNumThreadLocalSizeBrackets); 780 DCHECK(non_full_runs_[idx].find(run) == non_full_runs_[idx].end()); 781 DCHECK(full_runs_[idx].find(run) == full_runs_[idx].end()); 782 run->AddToThreadLocalFreeList(ptr); 783 if (kTraceRosAlloc) { 784 LOG(INFO) << "RosAlloc::FreeFromRun() : Freed a slot in a thread local run 0x" << std::hex 785 << reinterpret_cast<intptr_t>(run); 786 } 787 // A thread local run will be kept as a thread local even if it's become all free. 788 return bracket_size; 789 } 790 // Free the slot in the run. 791 run->FreeSlot(ptr); 792 auto* non_full_runs = &non_full_runs_[idx]; 793 if (run->IsAllFree()) { 794 // It has just become completely free. Free the pages of this run. 795 std::set<Run*>::iterator pos = non_full_runs->find(run); 796 if (pos != non_full_runs->end()) { 797 non_full_runs->erase(pos); 798 if (kTraceRosAlloc) { 799 LOG(INFO) << "RosAlloc::FreeFromRun() : Erased run 0x" << std::hex 800 << reinterpret_cast<intptr_t>(run) << " from non_full_runs_"; 801 } 802 } 803 if (run == current_runs_[idx]) { 804 current_runs_[idx] = dedicated_full_run_; 805 } 806 DCHECK(non_full_runs_[idx].find(run) == non_full_runs_[idx].end()); 807 DCHECK(full_runs_[idx].find(run) == full_runs_[idx].end()); 808 run->ZeroHeaderAndSlotHeaders(); 809 { 810 MutexLock lock_mu(self, lock_); 811 FreePages(self, run, true); 812 } 813 } else { 814 // It is not completely free. If it wasn't the current run or 815 // already in the non-full run set (i.e., it was full) insert it 816 // into the non-full run set. 817 if (run != current_runs_[idx]) { 818 auto* full_runs = kIsDebugBuild ? &full_runs_[idx] : nullptr; 819 auto pos = non_full_runs->find(run); 820 if (pos == non_full_runs->end()) { 821 DCHECK(run_was_full); 822 DCHECK(full_runs->find(run) != full_runs->end()); 823 if (kIsDebugBuild) { 824 full_runs->erase(run); 825 if (kTraceRosAlloc) { 826 LOG(INFO) << "RosAlloc::FreeFromRun() : Erased run 0x" << std::hex 827 << reinterpret_cast<intptr_t>(run) << " from full_runs_"; 828 } 829 } 830 non_full_runs->insert(run); 831 DCHECK(!run->IsFull()); 832 if (kTraceRosAlloc) { 833 LOG(INFO) << "RosAlloc::FreeFromRun() : Inserted run 0x" << std::hex 834 << reinterpret_cast<intptr_t>(run) 835 << " into non_full_runs_[" << std::dec << idx << "]"; 836 } 837 } 838 } 839 } 840 return bracket_size; 841 } 842 843 template<bool kUseTail> 844 std::string RosAlloc::Run::FreeListToStr(SlotFreeList<kUseTail>* free_list) { 845 std::string free_list_str; 846 const uint8_t idx = size_bracket_idx_; 847 const size_t bracket_size = bracketSizes[idx]; 848 for (Slot* slot = free_list->Head(); slot != nullptr; slot = slot->Next()) { 849 bool is_last = slot->Next() == nullptr; 850 uintptr_t slot_offset = reinterpret_cast<uintptr_t>(slot) - 851 reinterpret_cast<uintptr_t>(FirstSlot()); 852 DCHECK_EQ(slot_offset % bracket_size, 0U); 853 uintptr_t slot_idx = slot_offset / bracket_size; 854 if (!is_last) { 855 free_list_str.append(StringPrintf("%u-", static_cast<uint32_t>(slot_idx))); 856 } else { 857 free_list_str.append(StringPrintf("%u", static_cast<uint32_t>(slot_idx))); 858 } 859 } 860 return free_list_str; 861 } 862 863 std::string RosAlloc::Run::Dump() { 864 size_t idx = size_bracket_idx_; 865 std::ostringstream stream; 866 stream << "RosAlloc Run = " << reinterpret_cast<void*>(this) 867 << "{ magic_num=" << static_cast<int>(magic_num_) 868 << " size_bracket_idx=" << idx 869 << " is_thread_local=" << static_cast<int>(is_thread_local_) 870 << " to_be_bulk_freed=" << static_cast<int>(to_be_bulk_freed_) 871 << " free_list=" << FreeListToStr(&free_list_) 872 << " bulk_free_list=" << FreeListToStr(&bulk_free_list_) 873 << " thread_local_list=" << FreeListToStr(&thread_local_free_list_) 874 << " }" << std::endl; 875 return stream.str(); 876 } 877 878 void RosAlloc::Run::FreeSlot(void* ptr) { 879 DCHECK(!IsThreadLocal()); 880 const uint8_t idx = size_bracket_idx_; 881 const size_t bracket_size = bracketSizes[idx]; 882 Slot* slot = ToSlot(ptr); 883 // Zero out the memory. 884 // TODO: Investigate alternate memset since ptr is guaranteed to be aligned to 16. 885 memset(slot, 0, bracket_size); 886 free_list_.Add(slot); 887 if (kTraceRosAlloc) { 888 LOG(INFO) << "RosAlloc::Run::FreeSlot() : " << slot 889 << ", bracket_size=" << std::dec << bracket_size << ", slot_idx=" << SlotIndex(slot); 890 } 891 } 892 893 inline bool RosAlloc::Run::MergeThreadLocalFreeListToFreeList(bool* is_all_free_after_out) { 894 DCHECK(IsThreadLocal()); 895 // Merge the thread local free list into the free list and clear the thread local free list. 896 const uint8_t idx = size_bracket_idx_; 897 bool thread_local_free_list_size = thread_local_free_list_.Size(); 898 const size_t size_before = free_list_.Size(); 899 free_list_.Merge(&thread_local_free_list_); 900 const size_t size_after = free_list_.Size(); 901 DCHECK_EQ(size_before < size_after, thread_local_free_list_size > 0); 902 DCHECK_LE(size_before, size_after); 903 *is_all_free_after_out = free_list_.Size() == numOfSlots[idx]; 904 // Return true at least one slot was added to the free list. 905 return size_before < size_after; 906 } 907 908 inline void RosAlloc::Run::MergeBulkFreeListToFreeList() { 909 DCHECK(!IsThreadLocal()); 910 // Merge the bulk free list into the free list and clear the bulk free list. 911 free_list_.Merge(&bulk_free_list_); 912 } 913 914 inline void RosAlloc::Run::MergeBulkFreeListToThreadLocalFreeList() { 915 DCHECK(IsThreadLocal()); 916 // Merge the bulk free list into the thread local free list and clear the bulk free list. 917 thread_local_free_list_.Merge(&bulk_free_list_); 918 } 919 920 inline void RosAlloc::Run::AddToThreadLocalFreeList(void* ptr) { 921 DCHECK(IsThreadLocal()); 922 AddToFreeListShared(ptr, &thread_local_free_list_, __FUNCTION__); 923 } 924 925 inline size_t RosAlloc::Run::AddToBulkFreeList(void* ptr) { 926 return AddToFreeListShared(ptr, &bulk_free_list_, __FUNCTION__); 927 } 928 929 inline size_t RosAlloc::Run::AddToFreeListShared(void* ptr, 930 SlotFreeList<true>* free_list, 931 const char* caller_name) { 932 const uint8_t idx = size_bracket_idx_; 933 const size_t bracket_size = bracketSizes[idx]; 934 Slot* slot = ToSlot(ptr); 935 memset(slot, 0, bracket_size); 936 free_list->Add(slot); 937 if (kTraceRosAlloc) { 938 LOG(INFO) << "RosAlloc::Run::" << caller_name << "() : " << ptr 939 << ", bracket_size=" << std::dec << bracket_size << ", slot_idx=" << SlotIndex(slot); 940 } 941 return bracket_size; 942 } 943 944 inline void RosAlloc::Run::ZeroHeaderAndSlotHeaders() { 945 DCHECK(IsAllFree()); 946 const uint8_t idx = size_bracket_idx_; 947 // Zero the slot header (next pointers). 948 for (Slot* slot = free_list_.Head(); slot != nullptr; ) { 949 Slot* next_slot = slot->Next(); 950 slot->Clear(); 951 slot = next_slot; 952 } 953 // Zero the header. 954 memset(this, 0, headerSizes[idx]); 955 // Check that the entire run is all zero. 956 if (kIsDebugBuild) { 957 const size_t size = numOfPages[idx] * kPageSize; 958 const uintptr_t* word_ptr = reinterpret_cast<uintptr_t*>(this); 959 for (size_t i = 0; i < size / sizeof(uintptr_t); ++i) { 960 CHECK_EQ(word_ptr[i], 0U) << "words don't match at index " << i; 961 } 962 } 963 } 964 965 inline void RosAlloc::Run::ZeroData() { 966 const uint8_t idx = size_bracket_idx_; 967 uint8_t* slot_begin = reinterpret_cast<uint8_t*>(FirstSlot()); 968 memset(slot_begin, 0, numOfSlots[idx] * bracketSizes[idx]); 969 } 970 971 void RosAlloc::Run::InspectAllSlots(void (*handler)(void* start, void* end, size_t used_bytes, void* callback_arg), 972 void* arg) { 973 size_t idx = size_bracket_idx_; 974 uint8_t* slot_base = reinterpret_cast<uint8_t*>(this) + headerSizes[idx]; 975 size_t num_slots = numOfSlots[idx]; 976 size_t bracket_size = IndexToBracketSize(idx); 977 DCHECK_EQ(slot_base + num_slots * bracket_size, 978 reinterpret_cast<uint8_t*>(this) + numOfPages[idx] * kPageSize); 979 // Free slots are on the free list and the allocated/used slots are not. We traverse the free list 980 // to find out and record which slots are free in the is_free array. 981 std::unique_ptr<bool[]> is_free(new bool[num_slots]()); // zero initialized 982 for (Slot* slot = free_list_.Head(); slot != nullptr; slot = slot->Next()) { 983 size_t slot_idx = SlotIndex(slot); 984 DCHECK_LT(slot_idx, num_slots); 985 is_free[slot_idx] = true; 986 } 987 if (IsThreadLocal()) { 988 for (Slot* slot = thread_local_free_list_.Head(); slot != nullptr; slot = slot->Next()) { 989 size_t slot_idx = SlotIndex(slot); 990 DCHECK_LT(slot_idx, num_slots); 991 is_free[slot_idx] = true; 992 } 993 } 994 for (size_t slot_idx = 0; slot_idx < num_slots; ++slot_idx) { 995 uint8_t* slot_addr = slot_base + slot_idx * bracket_size; 996 if (!is_free[slot_idx]) { 997 handler(slot_addr, slot_addr + bracket_size, bracket_size, arg); 998 } else { 999 handler(slot_addr, slot_addr + bracket_size, 0, arg); 1000 } 1001 } 1002 } 1003 1004 // If true, read the page map entries in BulkFree() without using the 1005 // lock for better performance, assuming that the existence of an 1006 // allocated chunk/pointer being freed in BulkFree() guarantees that 1007 // the page map entry won't change. Disabled for now. 1008 static constexpr bool kReadPageMapEntryWithoutLockInBulkFree = true; 1009 1010 size_t RosAlloc::BulkFree(Thread* self, void** ptrs, size_t num_ptrs) { 1011 size_t freed_bytes = 0; 1012 if ((false)) { 1013 // Used only to test Free() as GC uses only BulkFree(). 1014 for (size_t i = 0; i < num_ptrs; ++i) { 1015 freed_bytes += FreeInternal(self, ptrs[i]); 1016 } 1017 return freed_bytes; 1018 } 1019 1020 WriterMutexLock wmu(self, bulk_free_lock_); 1021 1022 // First mark slots to free in the bulk free bit map without locking the 1023 // size bracket locks. On host, unordered_set is faster than vector + flag. 1024 #ifdef __ANDROID__ 1025 std::vector<Run*> runs; 1026 #else 1027 std::unordered_set<Run*, hash_run, eq_run> runs; 1028 #endif 1029 for (size_t i = 0; i < num_ptrs; i++) { 1030 void* ptr = ptrs[i]; 1031 DCHECK_LE(base_, ptr); 1032 DCHECK_LT(ptr, base_ + footprint_); 1033 size_t pm_idx = RoundDownToPageMapIndex(ptr); 1034 Run* run = nullptr; 1035 if (kReadPageMapEntryWithoutLockInBulkFree) { 1036 // Read the page map entries without locking the lock. 1037 uint8_t page_map_entry = page_map_[pm_idx]; 1038 if (kTraceRosAlloc) { 1039 LOG(INFO) << "RosAlloc::BulkFree() : " << std::hex << ptr << ", pm_idx=" 1040 << std::dec << pm_idx 1041 << ", page_map_entry=" << static_cast<int>(page_map_entry); 1042 } 1043 if (LIKELY(page_map_entry == kPageMapRun)) { 1044 run = reinterpret_cast<Run*>(base_ + pm_idx * kPageSize); 1045 } else if (LIKELY(page_map_entry == kPageMapRunPart)) { 1046 size_t pi = pm_idx; 1047 // Find the beginning of the run. 1048 do { 1049 --pi; 1050 DCHECK_LT(pi, capacity_ / kPageSize); 1051 } while (page_map_[pi] != kPageMapRun); 1052 run = reinterpret_cast<Run*>(base_ + pi * kPageSize); 1053 } else if (page_map_entry == kPageMapLargeObject) { 1054 MutexLock mu(self, lock_); 1055 freed_bytes += FreePages(self, ptr, false); 1056 continue; 1057 } else { 1058 LOG(FATAL) << "Unreachable - page map type: " << static_cast<int>(page_map_entry); 1059 } 1060 } else { 1061 // Read the page map entries with a lock. 1062 MutexLock mu(self, lock_); 1063 DCHECK_LT(pm_idx, page_map_size_); 1064 uint8_t page_map_entry = page_map_[pm_idx]; 1065 if (kTraceRosAlloc) { 1066 LOG(INFO) << "RosAlloc::BulkFree() : " << std::hex << ptr << ", pm_idx=" 1067 << std::dec << pm_idx 1068 << ", page_map_entry=" << static_cast<int>(page_map_entry); 1069 } 1070 if (LIKELY(page_map_entry == kPageMapRun)) { 1071 run = reinterpret_cast<Run*>(base_ + pm_idx * kPageSize); 1072 } else if (LIKELY(page_map_entry == kPageMapRunPart)) { 1073 size_t pi = pm_idx; 1074 // Find the beginning of the run. 1075 do { 1076 --pi; 1077 DCHECK_LT(pi, capacity_ / kPageSize); 1078 } while (page_map_[pi] != kPageMapRun); 1079 run = reinterpret_cast<Run*>(base_ + pi * kPageSize); 1080 } else if (page_map_entry == kPageMapLargeObject) { 1081 freed_bytes += FreePages(self, ptr, false); 1082 continue; 1083 } else { 1084 LOG(FATAL) << "Unreachable - page map type: " << static_cast<int>(page_map_entry); 1085 } 1086 } 1087 DCHECK(run != nullptr); 1088 DCHECK_EQ(run->magic_num_, kMagicNum); 1089 // Set the bit in the bulk free bit map. 1090 freed_bytes += run->AddToBulkFreeList(ptr); 1091 #ifdef __ANDROID__ 1092 if (!run->to_be_bulk_freed_) { 1093 run->to_be_bulk_freed_ = true; 1094 runs.push_back(run); 1095 } 1096 #else 1097 runs.insert(run); 1098 #endif 1099 } 1100 1101 // Now, iterate over the affected runs and update the alloc bit map 1102 // based on the bulk free bit map (for non-thread-local runs) and 1103 // union the bulk free bit map into the thread-local free bit map 1104 // (for thread-local runs.) 1105 for (Run* run : runs) { 1106 #ifdef __ANDROID__ 1107 DCHECK(run->to_be_bulk_freed_); 1108 run->to_be_bulk_freed_ = false; 1109 #endif 1110 size_t idx = run->size_bracket_idx_; 1111 MutexLock brackets_mu(self, *size_bracket_locks_[idx]); 1112 if (run->IsThreadLocal()) { 1113 DCHECK_LT(run->size_bracket_idx_, kNumThreadLocalSizeBrackets); 1114 DCHECK(non_full_runs_[idx].find(run) == non_full_runs_[idx].end()); 1115 DCHECK(full_runs_[idx].find(run) == full_runs_[idx].end()); 1116 run->MergeBulkFreeListToThreadLocalFreeList(); 1117 if (kTraceRosAlloc) { 1118 LOG(INFO) << "RosAlloc::BulkFree() : Freed slot(s) in a thread local run 0x" 1119 << std::hex << reinterpret_cast<intptr_t>(run); 1120 } 1121 DCHECK(run->IsThreadLocal()); 1122 // A thread local run will be kept as a thread local even if 1123 // it's become all free. 1124 } else { 1125 bool run_was_full = run->IsFull(); 1126 run->MergeBulkFreeListToFreeList(); 1127 if (kTraceRosAlloc) { 1128 LOG(INFO) << "RosAlloc::BulkFree() : Freed slot(s) in a run 0x" << std::hex 1129 << reinterpret_cast<intptr_t>(run); 1130 } 1131 // Check if the run should be moved to non_full_runs_ or 1132 // free_page_runs_. 1133 auto* non_full_runs = &non_full_runs_[idx]; 1134 auto* full_runs = kIsDebugBuild ? &full_runs_[idx] : nullptr; 1135 if (run->IsAllFree()) { 1136 // It has just become completely free. Free the pages of the 1137 // run. 1138 bool run_was_current = run == current_runs_[idx]; 1139 if (run_was_current) { 1140 DCHECK(full_runs->find(run) == full_runs->end()); 1141 DCHECK(non_full_runs->find(run) == non_full_runs->end()); 1142 // If it was a current run, reuse it. 1143 } else if (run_was_full) { 1144 // If it was full, remove it from the full run set (debug 1145 // only.) 1146 if (kIsDebugBuild) { 1147 std::unordered_set<Run*, hash_run, eq_run>::iterator pos = full_runs->find(run); 1148 DCHECK(pos != full_runs->end()); 1149 full_runs->erase(pos); 1150 if (kTraceRosAlloc) { 1151 LOG(INFO) << "RosAlloc::BulkFree() : Erased run 0x" << std::hex 1152 << reinterpret_cast<intptr_t>(run) 1153 << " from full_runs_"; 1154 } 1155 DCHECK(full_runs->find(run) == full_runs->end()); 1156 } 1157 } else { 1158 // If it was in a non full run set, remove it from the set. 1159 DCHECK(full_runs->find(run) == full_runs->end()); 1160 DCHECK(non_full_runs->find(run) != non_full_runs->end()); 1161 non_full_runs->erase(run); 1162 if (kTraceRosAlloc) { 1163 LOG(INFO) << "RosAlloc::BulkFree() : Erased run 0x" << std::hex 1164 << reinterpret_cast<intptr_t>(run) 1165 << " from non_full_runs_"; 1166 } 1167 DCHECK(non_full_runs->find(run) == non_full_runs->end()); 1168 } 1169 if (!run_was_current) { 1170 run->ZeroHeaderAndSlotHeaders(); 1171 MutexLock lock_mu(self, lock_); 1172 FreePages(self, run, true); 1173 } 1174 } else { 1175 // It is not completely free. If it wasn't the current run or 1176 // already in the non-full run set (i.e., it was full) insert 1177 // it into the non-full run set. 1178 if (run == current_runs_[idx]) { 1179 DCHECK(non_full_runs->find(run) == non_full_runs->end()); 1180 DCHECK(full_runs->find(run) == full_runs->end()); 1181 // If it was a current run, keep it. 1182 } else if (run_was_full) { 1183 // If it was full, remove it from the full run set (debug 1184 // only) and insert into the non-full run set. 1185 DCHECK(full_runs->find(run) != full_runs->end()); 1186 DCHECK(non_full_runs->find(run) == non_full_runs->end()); 1187 if (kIsDebugBuild) { 1188 full_runs->erase(run); 1189 if (kTraceRosAlloc) { 1190 LOG(INFO) << "RosAlloc::BulkFree() : Erased run 0x" << std::hex 1191 << reinterpret_cast<intptr_t>(run) 1192 << " from full_runs_"; 1193 } 1194 } 1195 non_full_runs->insert(run); 1196 if (kTraceRosAlloc) { 1197 LOG(INFO) << "RosAlloc::BulkFree() : Inserted run 0x" << std::hex 1198 << reinterpret_cast<intptr_t>(run) 1199 << " into non_full_runs_[" << std::dec << idx; 1200 } 1201 } else { 1202 // If it was not full, so leave it in the non full run set. 1203 DCHECK(full_runs->find(run) == full_runs->end()); 1204 DCHECK(non_full_runs->find(run) != non_full_runs->end()); 1205 } 1206 } 1207 } 1208 } 1209 return freed_bytes; 1210 } 1211 1212 std::string RosAlloc::DumpPageMap() { 1213 std::ostringstream stream; 1214 stream << "RosAlloc PageMap: " << std::endl; 1215 lock_.AssertHeld(Thread::Current()); 1216 size_t end = page_map_size_; 1217 FreePageRun* curr_fpr = nullptr; 1218 size_t curr_fpr_size = 0; 1219 size_t remaining_curr_fpr_size = 0; 1220 size_t num_running_empty_pages = 0; 1221 for (size_t i = 0; i < end; ++i) { 1222 uint8_t pm = page_map_[i]; 1223 switch (pm) { 1224 case kPageMapReleased: 1225 // Fall-through. 1226 case kPageMapEmpty: { 1227 FreePageRun* fpr = reinterpret_cast<FreePageRun*>(base_ + i * kPageSize); 1228 if (free_page_runs_.find(fpr) != free_page_runs_.end()) { 1229 // Encountered a fresh free page run. 1230 DCHECK_EQ(remaining_curr_fpr_size, static_cast<size_t>(0)); 1231 DCHECK(fpr->IsFree()); 1232 DCHECK(curr_fpr == nullptr); 1233 DCHECK_EQ(curr_fpr_size, static_cast<size_t>(0)); 1234 curr_fpr = fpr; 1235 curr_fpr_size = fpr->ByteSize(this); 1236 DCHECK_EQ(curr_fpr_size % kPageSize, static_cast<size_t>(0)); 1237 remaining_curr_fpr_size = curr_fpr_size - kPageSize; 1238 stream << "[" << i << "]=" << (pm == kPageMapReleased ? "Released" : "Empty") 1239 << " (FPR start) fpr_size=" << curr_fpr_size 1240 << " remaining_fpr_size=" << remaining_curr_fpr_size << std::endl; 1241 if (remaining_curr_fpr_size == 0) { 1242 // Reset at the end of the current free page run. 1243 curr_fpr = nullptr; 1244 curr_fpr_size = 0; 1245 } 1246 stream << "curr_fpr=0x" << std::hex << reinterpret_cast<intptr_t>(curr_fpr) << std::endl; 1247 DCHECK_EQ(num_running_empty_pages, static_cast<size_t>(0)); 1248 } else { 1249 // Still part of the current free page run. 1250 DCHECK_NE(num_running_empty_pages, static_cast<size_t>(0)); 1251 DCHECK(curr_fpr != nullptr && curr_fpr_size > 0 && remaining_curr_fpr_size > 0); 1252 DCHECK_EQ(remaining_curr_fpr_size % kPageSize, static_cast<size_t>(0)); 1253 DCHECK_GE(remaining_curr_fpr_size, static_cast<size_t>(kPageSize)); 1254 remaining_curr_fpr_size -= kPageSize; 1255 stream << "[" << i << "]=Empty (FPR part)" 1256 << " remaining_fpr_size=" << remaining_curr_fpr_size << std::endl; 1257 if (remaining_curr_fpr_size == 0) { 1258 // Reset at the end of the current free page run. 1259 curr_fpr = nullptr; 1260 curr_fpr_size = 0; 1261 } 1262 } 1263 num_running_empty_pages++; 1264 break; 1265 } 1266 case kPageMapLargeObject: { 1267 DCHECK_EQ(remaining_curr_fpr_size, static_cast<size_t>(0)); 1268 num_running_empty_pages = 0; 1269 stream << "[" << i << "]=Large (start)" << std::endl; 1270 break; 1271 } 1272 case kPageMapLargeObjectPart: 1273 DCHECK_EQ(remaining_curr_fpr_size, static_cast<size_t>(0)); 1274 num_running_empty_pages = 0; 1275 stream << "[" << i << "]=Large (part)" << std::endl; 1276 break; 1277 case kPageMapRun: { 1278 DCHECK_EQ(remaining_curr_fpr_size, static_cast<size_t>(0)); 1279 num_running_empty_pages = 0; 1280 Run* run = reinterpret_cast<Run*>(base_ + i * kPageSize); 1281 size_t idx = run->size_bracket_idx_; 1282 stream << "[" << i << "]=Run (start)" 1283 << " idx=" << idx 1284 << " numOfPages=" << numOfPages[idx] 1285 << " is_thread_local=" << run->is_thread_local_ 1286 << " is_all_free=" << (run->IsAllFree() ? 1 : 0) 1287 << std::endl; 1288 break; 1289 } 1290 case kPageMapRunPart: 1291 DCHECK_EQ(remaining_curr_fpr_size, static_cast<size_t>(0)); 1292 num_running_empty_pages = 0; 1293 stream << "[" << i << "]=Run (part)" << std::endl; 1294 break; 1295 default: 1296 stream << "[" << i << "]=Unrecognizable page map type: " << pm; 1297 break; 1298 } 1299 } 1300 return stream.str(); 1301 } 1302 1303 size_t RosAlloc::UsableSize(const void* ptr) { 1304 DCHECK_LE(base_, ptr); 1305 DCHECK_LT(ptr, base_ + footprint_); 1306 size_t pm_idx = RoundDownToPageMapIndex(ptr); 1307 MutexLock mu(Thread::Current(), lock_); 1308 switch (page_map_[pm_idx]) { 1309 case kPageMapReleased: 1310 // Fall-through. 1311 case kPageMapEmpty: 1312 LOG(FATAL) << "Unreachable - " << __PRETTY_FUNCTION__ << ": pm_idx=" << pm_idx << ", ptr=" 1313 << std::hex << reinterpret_cast<intptr_t>(ptr); 1314 break; 1315 case kPageMapLargeObject: { 1316 size_t num_pages = 1; 1317 size_t idx = pm_idx + 1; 1318 size_t end = page_map_size_; 1319 while (idx < end && page_map_[idx] == kPageMapLargeObjectPart) { 1320 num_pages++; 1321 idx++; 1322 } 1323 return num_pages * kPageSize; 1324 } 1325 case kPageMapLargeObjectPart: 1326 LOG(FATAL) << "Unreachable - " << __PRETTY_FUNCTION__ << ": pm_idx=" << pm_idx << ", ptr=" 1327 << std::hex << reinterpret_cast<intptr_t>(ptr); 1328 break; 1329 case kPageMapRun: 1330 case kPageMapRunPart: { 1331 // Find the beginning of the run. 1332 while (page_map_[pm_idx] != kPageMapRun) { 1333 pm_idx--; 1334 DCHECK_LT(pm_idx, capacity_ / kPageSize); 1335 } 1336 DCHECK_EQ(page_map_[pm_idx], kPageMapRun); 1337 Run* run = reinterpret_cast<Run*>(base_ + pm_idx * kPageSize); 1338 DCHECK_EQ(run->magic_num_, kMagicNum); 1339 size_t idx = run->size_bracket_idx_; 1340 size_t offset_from_slot_base = reinterpret_cast<const uint8_t*>(ptr) 1341 - (reinterpret_cast<uint8_t*>(run) + headerSizes[idx]); 1342 DCHECK_EQ(offset_from_slot_base % bracketSizes[idx], static_cast<size_t>(0)); 1343 return IndexToBracketSize(idx); 1344 } 1345 default: { 1346 LOG(FATAL) << "Unreachable - page map type: " << static_cast<int>(page_map_[pm_idx]); 1347 break; 1348 } 1349 } 1350 return 0; 1351 } 1352 1353 bool RosAlloc::Trim() { 1354 MutexLock mu(Thread::Current(), lock_); 1355 FreePageRun* last_free_page_run; 1356 DCHECK_EQ(footprint_ % kPageSize, static_cast<size_t>(0)); 1357 auto it = free_page_runs_.rbegin(); 1358 if (it != free_page_runs_.rend() && (last_free_page_run = *it)->End(this) == base_ + footprint_) { 1359 // Remove the last free page run, if any. 1360 DCHECK(last_free_page_run->IsFree()); 1361 DCHECK(IsFreePage(ToPageMapIndex(last_free_page_run))); 1362 DCHECK_EQ(last_free_page_run->ByteSize(this) % kPageSize, static_cast<size_t>(0)); 1363 DCHECK_EQ(last_free_page_run->End(this), base_ + footprint_); 1364 free_page_runs_.erase(last_free_page_run); 1365 size_t decrement = last_free_page_run->ByteSize(this); 1366 size_t new_footprint = footprint_ - decrement; 1367 DCHECK_EQ(new_footprint % kPageSize, static_cast<size_t>(0)); 1368 size_t new_num_of_pages = new_footprint / kPageSize; 1369 DCHECK_GE(page_map_size_, new_num_of_pages); 1370 // Zero out the tail of the page map. 1371 uint8_t* zero_begin = const_cast<uint8_t*>(page_map_) + new_num_of_pages; 1372 uint8_t* madvise_begin = AlignUp(zero_begin, kPageSize); 1373 DCHECK_LE(madvise_begin, page_map_mem_map_->End()); 1374 size_t madvise_size = page_map_mem_map_->End() - madvise_begin; 1375 if (madvise_size > 0) { 1376 DCHECK_ALIGNED(madvise_begin, kPageSize); 1377 DCHECK_EQ(RoundUp(madvise_size, kPageSize), madvise_size); 1378 if (!kMadviseZeroes) { 1379 memset(madvise_begin, 0, madvise_size); 1380 } 1381 CHECK_EQ(madvise(madvise_begin, madvise_size, MADV_DONTNEED), 0); 1382 } 1383 if (madvise_begin - zero_begin) { 1384 memset(zero_begin, 0, madvise_begin - zero_begin); 1385 } 1386 page_map_size_ = new_num_of_pages; 1387 free_page_run_size_map_.resize(new_num_of_pages); 1388 DCHECK_EQ(free_page_run_size_map_.size(), new_num_of_pages); 1389 ArtRosAllocMoreCore(this, -(static_cast<intptr_t>(decrement))); 1390 if (kTraceRosAlloc) { 1391 LOG(INFO) << "RosAlloc::Trim() : decreased the footprint from " 1392 << footprint_ << " to " << new_footprint; 1393 } 1394 DCHECK_LT(new_footprint, footprint_); 1395 DCHECK_LT(new_footprint, capacity_); 1396 footprint_ = new_footprint; 1397 return true; 1398 } 1399 return false; 1400 } 1401 1402 void RosAlloc::InspectAll(void (*handler)(void* start, void* end, size_t used_bytes, void* callback_arg), 1403 void* arg) { 1404 // Note: no need to use this to release pages as we already do so in FreePages(). 1405 if (handler == nullptr) { 1406 return; 1407 } 1408 MutexLock mu(Thread::Current(), lock_); 1409 size_t pm_end = page_map_size_; 1410 size_t i = 0; 1411 while (i < pm_end) { 1412 uint8_t pm = page_map_[i]; 1413 switch (pm) { 1414 case kPageMapReleased: 1415 // Fall-through. 1416 case kPageMapEmpty: { 1417 // The start of a free page run. 1418 FreePageRun* fpr = reinterpret_cast<FreePageRun*>(base_ + i * kPageSize); 1419 DCHECK(free_page_runs_.find(fpr) != free_page_runs_.end()); 1420 size_t fpr_size = fpr->ByteSize(this); 1421 DCHECK_ALIGNED(fpr_size, kPageSize); 1422 void* start = fpr; 1423 if (kIsDebugBuild) { 1424 // In the debug build, the first page of a free page run 1425 // contains a magic number for debugging. Exclude it. 1426 start = reinterpret_cast<uint8_t*>(fpr) + kPageSize; 1427 } 1428 void* end = reinterpret_cast<uint8_t*>(fpr) + fpr_size; 1429 handler(start, end, 0, arg); 1430 size_t num_pages = fpr_size / kPageSize; 1431 if (kIsDebugBuild) { 1432 for (size_t j = i + 1; j < i + num_pages; ++j) { 1433 DCHECK(IsFreePage(j)); 1434 } 1435 } 1436 i += fpr_size / kPageSize; 1437 DCHECK_LE(i, pm_end); 1438 break; 1439 } 1440 case kPageMapLargeObject: { 1441 // The start of a large object. 1442 size_t num_pages = 1; 1443 size_t idx = i + 1; 1444 while (idx < pm_end && page_map_[idx] == kPageMapLargeObjectPart) { 1445 num_pages++; 1446 idx++; 1447 } 1448 void* start = base_ + i * kPageSize; 1449 void* end = base_ + (i + num_pages) * kPageSize; 1450 size_t used_bytes = num_pages * kPageSize; 1451 handler(start, end, used_bytes, arg); 1452 if (kIsDebugBuild) { 1453 for (size_t j = i + 1; j < i + num_pages; ++j) { 1454 DCHECK_EQ(page_map_[j], kPageMapLargeObjectPart); 1455 } 1456 } 1457 i += num_pages; 1458 DCHECK_LE(i, pm_end); 1459 break; 1460 } 1461 case kPageMapLargeObjectPart: 1462 LOG(FATAL) << "Unreachable - page map type: " << static_cast<int>(pm); 1463 break; 1464 case kPageMapRun: { 1465 // The start of a run. 1466 Run* run = reinterpret_cast<Run*>(base_ + i * kPageSize); 1467 DCHECK_EQ(run->magic_num_, kMagicNum); 1468 // The dedicated full run doesn't contain any real allocations, don't visit the slots in 1469 // there. 1470 run->InspectAllSlots(handler, arg); 1471 size_t num_pages = numOfPages[run->size_bracket_idx_]; 1472 if (kIsDebugBuild) { 1473 for (size_t j = i + 1; j < i + num_pages; ++j) { 1474 DCHECK_EQ(page_map_[j], kPageMapRunPart); 1475 } 1476 } 1477 i += num_pages; 1478 DCHECK_LE(i, pm_end); 1479 break; 1480 } 1481 case kPageMapRunPart: 1482 LOG(FATAL) << "Unreachable - page map type: " << static_cast<int>(pm); 1483 break; 1484 default: 1485 LOG(FATAL) << "Unreachable - page map type: " << static_cast<int>(pm); 1486 break; 1487 } 1488 } 1489 } 1490 1491 size_t RosAlloc::Footprint() { 1492 MutexLock mu(Thread::Current(), lock_); 1493 return footprint_; 1494 } 1495 1496 size_t RosAlloc::FootprintLimit() { 1497 MutexLock mu(Thread::Current(), lock_); 1498 return capacity_; 1499 } 1500 1501 void RosAlloc::SetFootprintLimit(size_t new_capacity) { 1502 MutexLock mu(Thread::Current(), lock_); 1503 DCHECK_EQ(RoundUp(new_capacity, kPageSize), new_capacity); 1504 // Only growing is supported here. But Trim() is supported. 1505 if (capacity_ < new_capacity) { 1506 CHECK_LE(new_capacity, max_capacity_); 1507 capacity_ = new_capacity; 1508 VLOG(heap) << "new capacity=" << capacity_; 1509 } 1510 } 1511 1512 // Below may be called by mutator itself just before thread termination. 1513 size_t RosAlloc::RevokeThreadLocalRuns(Thread* thread) { 1514 Thread* self = Thread::Current(); 1515 size_t free_bytes = 0U; 1516 for (size_t idx = 0; idx < kNumThreadLocalSizeBrackets; idx++) { 1517 MutexLock mu(self, *size_bracket_locks_[idx]); 1518 Run* thread_local_run = reinterpret_cast<Run*>(thread->GetRosAllocRun(idx)); 1519 CHECK(thread_local_run != nullptr); 1520 // Invalid means already revoked. 1521 DCHECK(thread_local_run->IsThreadLocal()); 1522 if (thread_local_run != dedicated_full_run_) { 1523 // Note the thread local run may not be full here. 1524 thread->SetRosAllocRun(idx, dedicated_full_run_); 1525 DCHECK_EQ(thread_local_run->magic_num_, kMagicNum); 1526 // Count the number of free slots left. 1527 size_t num_free_slots = thread_local_run->NumberOfFreeSlots(); 1528 free_bytes += num_free_slots * bracketSizes[idx]; 1529 // The above bracket index lock guards thread local free list to avoid race condition 1530 // with unioning bulk free list to thread local free list by GC thread in BulkFree. 1531 // If thread local run is true, GC thread will help update thread local free list 1532 // in BulkFree. And the latest thread local free list will be merged to free list 1533 // either when this thread local run is full or when revoking this run here. In this 1534 // case the free list wll be updated. If thread local run is false, GC thread will help 1535 // merge bulk free list in next BulkFree. 1536 // Thus no need to merge bulk free list to free list again here. 1537 bool dont_care; 1538 thread_local_run->MergeThreadLocalFreeListToFreeList(&dont_care); 1539 thread_local_run->SetIsThreadLocal(false); 1540 DCHECK(non_full_runs_[idx].find(thread_local_run) == non_full_runs_[idx].end()); 1541 DCHECK(full_runs_[idx].find(thread_local_run) == full_runs_[idx].end()); 1542 RevokeRun(self, idx, thread_local_run); 1543 } 1544 } 1545 return free_bytes; 1546 } 1547 1548 void RosAlloc::RevokeRun(Thread* self, size_t idx, Run* run) { 1549 size_bracket_locks_[idx]->AssertHeld(self); 1550 DCHECK(run != dedicated_full_run_); 1551 if (run->IsFull()) { 1552 if (kIsDebugBuild) { 1553 full_runs_[idx].insert(run); 1554 DCHECK(full_runs_[idx].find(run) != full_runs_[idx].end()); 1555 if (kTraceRosAlloc) { 1556 LOG(INFO) << __PRETTY_FUNCTION__ << " : Inserted run 0x" << std::hex 1557 << reinterpret_cast<intptr_t>(run) 1558 << " into full_runs_[" << std::dec << idx << "]"; 1559 } 1560 } 1561 } else if (run->IsAllFree()) { 1562 run->ZeroHeaderAndSlotHeaders(); 1563 MutexLock mu(self, lock_); 1564 FreePages(self, run, true); 1565 } else { 1566 non_full_runs_[idx].insert(run); 1567 DCHECK(non_full_runs_[idx].find(run) != non_full_runs_[idx].end()); 1568 if (kTraceRosAlloc) { 1569 LOG(INFO) << __PRETTY_FUNCTION__ << " : Inserted run 0x" << std::hex 1570 << reinterpret_cast<intptr_t>(run) 1571 << " into non_full_runs_[" << std::dec << idx << "]"; 1572 } 1573 } 1574 } 1575 1576 void RosAlloc::RevokeThreadUnsafeCurrentRuns() { 1577 // Revoke the current runs which share the same idx as thread local runs. 1578 Thread* self = Thread::Current(); 1579 for (size_t idx = 0; idx < kNumThreadLocalSizeBrackets; ++idx) { 1580 MutexLock mu(self, *size_bracket_locks_[idx]); 1581 if (current_runs_[idx] != dedicated_full_run_) { 1582 RevokeRun(self, idx, current_runs_[idx]); 1583 current_runs_[idx] = dedicated_full_run_; 1584 } 1585 } 1586 } 1587 1588 size_t RosAlloc::RevokeAllThreadLocalRuns() { 1589 // This is called when a mutator thread won't allocate such as at 1590 // the Zygote creation time or during the GC pause. 1591 MutexLock mu(Thread::Current(), *Locks::runtime_shutdown_lock_); 1592 MutexLock mu2(Thread::Current(), *Locks::thread_list_lock_); 1593 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 1594 size_t free_bytes = 0U; 1595 for (Thread* thread : thread_list) { 1596 free_bytes += RevokeThreadLocalRuns(thread); 1597 } 1598 RevokeThreadUnsafeCurrentRuns(); 1599 return free_bytes; 1600 } 1601 1602 void RosAlloc::AssertThreadLocalRunsAreRevoked(Thread* thread) { 1603 if (kIsDebugBuild) { 1604 Thread* self = Thread::Current(); 1605 // Avoid race conditions on the bulk free bit maps with BulkFree() (GC). 1606 ReaderMutexLock wmu(self, bulk_free_lock_); 1607 for (size_t idx = 0; idx < kNumThreadLocalSizeBrackets; idx++) { 1608 MutexLock mu(self, *size_bracket_locks_[idx]); 1609 Run* thread_local_run = reinterpret_cast<Run*>(thread->GetRosAllocRun(idx)); 1610 DCHECK(thread_local_run == nullptr || thread_local_run == dedicated_full_run_); 1611 } 1612 } 1613 } 1614 1615 void RosAlloc::AssertAllThreadLocalRunsAreRevoked() { 1616 if (kIsDebugBuild) { 1617 Thread* self = Thread::Current(); 1618 MutexLock shutdown_mu(self, *Locks::runtime_shutdown_lock_); 1619 MutexLock thread_list_mu(self, *Locks::thread_list_lock_); 1620 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 1621 for (Thread* t : thread_list) { 1622 AssertThreadLocalRunsAreRevoked(t); 1623 } 1624 for (size_t idx = 0; idx < kNumThreadLocalSizeBrackets; ++idx) { 1625 MutexLock brackets_mu(self, *size_bracket_locks_[idx]); 1626 CHECK_EQ(current_runs_[idx], dedicated_full_run_); 1627 } 1628 } 1629 } 1630 1631 void RosAlloc::Initialize() { 1632 // bracketSizes. 1633 static_assert(kNumRegularSizeBrackets == kNumOfSizeBrackets - 2, 1634 "There should be two non-regular brackets"); 1635 for (size_t i = 0; i < kNumOfSizeBrackets; i++) { 1636 if (i < kNumThreadLocalSizeBrackets) { 1637 bracketSizes[i] = kThreadLocalBracketQuantumSize * (i + 1); 1638 } else if (i < kNumRegularSizeBrackets) { 1639 bracketSizes[i] = kBracketQuantumSize * (i - kNumThreadLocalSizeBrackets + 1) + 1640 (kThreadLocalBracketQuantumSize * kNumThreadLocalSizeBrackets); 1641 } else if (i == kNumOfSizeBrackets - 2) { 1642 bracketSizes[i] = 1 * KB; 1643 } else { 1644 DCHECK_EQ(i, kNumOfSizeBrackets - 1); 1645 bracketSizes[i] = 2 * KB; 1646 } 1647 if (kTraceRosAlloc) { 1648 LOG(INFO) << "bracketSizes[" << i << "]=" << bracketSizes[i]; 1649 } 1650 } 1651 // numOfPages. 1652 for (size_t i = 0; i < kNumOfSizeBrackets; i++) { 1653 if (i < kNumThreadLocalSizeBrackets) { 1654 numOfPages[i] = 1; 1655 } else if (i < (kNumThreadLocalSizeBrackets + kNumRegularSizeBrackets) / 2) { 1656 numOfPages[i] = 1; 1657 } else if (i < kNumRegularSizeBrackets) { 1658 numOfPages[i] = 1; 1659 } else if (i == kNumOfSizeBrackets - 2) { 1660 numOfPages[i] = 2; 1661 } else { 1662 DCHECK_EQ(i, kNumOfSizeBrackets - 1); 1663 numOfPages[i] = 4; 1664 } 1665 if (kTraceRosAlloc) { 1666 LOG(INFO) << "numOfPages[" << i << "]=" << numOfPages[i]; 1667 } 1668 } 1669 // Compute numOfSlots and slotOffsets. 1670 for (size_t i = 0; i < kNumOfSizeBrackets; i++) { 1671 size_t bracket_size = bracketSizes[i]; 1672 size_t run_size = kPageSize * numOfPages[i]; 1673 size_t max_num_of_slots = run_size / bracket_size; 1674 // Compute the actual number of slots by taking the header and 1675 // alignment into account. 1676 size_t fixed_header_size = RoundUp(Run::fixed_header_size(), sizeof(uint64_t)); 1677 DCHECK_EQ(fixed_header_size, 80U); 1678 size_t header_size = 0; 1679 size_t num_of_slots = 0; 1680 // Search for the maximum number of slots that allows enough space 1681 // for the header. 1682 for (int s = max_num_of_slots; s >= 0; s--) { 1683 size_t tmp_slots_size = bracket_size * s; 1684 size_t tmp_unaligned_header_size = fixed_header_size; 1685 // Align up the unaligned header size. bracket_size may not be a power of two. 1686 size_t tmp_header_size = (tmp_unaligned_header_size % bracket_size == 0) ? 1687 tmp_unaligned_header_size : 1688 tmp_unaligned_header_size + (bracket_size - tmp_unaligned_header_size % bracket_size); 1689 DCHECK_EQ(tmp_header_size % bracket_size, 0U); 1690 DCHECK_EQ(tmp_header_size % sizeof(uint64_t), 0U); 1691 if (tmp_slots_size + tmp_header_size <= run_size) { 1692 // Found the right number of slots, that is, there was enough 1693 // space for the header (including the bit maps.) 1694 num_of_slots = s; 1695 header_size = tmp_header_size; 1696 break; 1697 } 1698 } 1699 DCHECK_GT(num_of_slots, 0U) << i; 1700 DCHECK_GT(header_size, 0U) << i; 1701 // Add the padding for the alignment remainder. 1702 header_size += run_size % bracket_size; 1703 DCHECK_EQ(header_size + num_of_slots * bracket_size, run_size); 1704 numOfSlots[i] = num_of_slots; 1705 headerSizes[i] = header_size; 1706 if (kTraceRosAlloc) { 1707 LOG(INFO) << "numOfSlots[" << i << "]=" << numOfSlots[i] 1708 << ", headerSizes[" << i << "]=" << headerSizes[i]; 1709 } 1710 } 1711 // Set up the dedicated full run so that nobody can successfully allocate from it. 1712 if (kIsDebugBuild) { 1713 dedicated_full_run_->magic_num_ = kMagicNum; 1714 } 1715 // It doesn't matter which size bracket we use since the main goal is to have the allocation 1716 // fail 100% of the time you attempt to allocate into the dedicated full run. 1717 dedicated_full_run_->size_bracket_idx_ = 0; 1718 DCHECK_EQ(dedicated_full_run_->FreeList()->Size(), 0U); // It looks full. 1719 dedicated_full_run_->SetIsThreadLocal(true); 1720 1721 // The smallest bracket size must be at least as large as the sizeof(Slot). 1722 DCHECK_LE(sizeof(Slot), bracketSizes[0]) << "sizeof(Slot) <= the smallest bracket size"; 1723 // Check the invariants between the max bracket sizes and the number of brackets. 1724 DCHECK_EQ(kMaxThreadLocalBracketSize, bracketSizes[kNumThreadLocalSizeBrackets - 1]); 1725 DCHECK_EQ(kMaxRegularBracketSize, bracketSizes[kNumRegularSizeBrackets - 1]); 1726 } 1727 1728 void RosAlloc::BytesAllocatedCallback(void* start ATTRIBUTE_UNUSED, void* end ATTRIBUTE_UNUSED, 1729 size_t used_bytes, void* arg) { 1730 if (used_bytes == 0) { 1731 return; 1732 } 1733 size_t* bytes_allocated = reinterpret_cast<size_t*>(arg); 1734 *bytes_allocated += used_bytes; 1735 } 1736 1737 void RosAlloc::ObjectsAllocatedCallback(void* start ATTRIBUTE_UNUSED, void* end ATTRIBUTE_UNUSED, 1738 size_t used_bytes, void* arg) { 1739 if (used_bytes == 0) { 1740 return; 1741 } 1742 size_t* objects_allocated = reinterpret_cast<size_t*>(arg); 1743 ++(*objects_allocated); 1744 } 1745 1746 void RosAlloc::Verify() { 1747 Thread* self = Thread::Current(); 1748 CHECK(Locks::mutator_lock_->IsExclusiveHeld(self)) 1749 << "The mutator locks isn't exclusively locked at " << __PRETTY_FUNCTION__; 1750 MutexLock thread_list_mu(self, *Locks::thread_list_lock_); 1751 ReaderMutexLock wmu(self, bulk_free_lock_); 1752 std::vector<Run*> runs; 1753 { 1754 MutexLock lock_mu(self, lock_); 1755 size_t pm_end = page_map_size_; 1756 size_t i = 0; 1757 size_t memory_tool_modifier = is_running_on_memory_tool_ ? 1758 2 * ::art::gc::space::kDefaultMemoryToolRedZoneBytes : // Redzones before and after. 1759 0; 1760 while (i < pm_end) { 1761 uint8_t pm = page_map_[i]; 1762 switch (pm) { 1763 case kPageMapReleased: 1764 // Fall-through. 1765 case kPageMapEmpty: { 1766 // The start of a free page run. 1767 FreePageRun* fpr = reinterpret_cast<FreePageRun*>(base_ + i * kPageSize); 1768 DCHECK_EQ(fpr->magic_num_, kMagicNumFree); 1769 CHECK(free_page_runs_.find(fpr) != free_page_runs_.end()) 1770 << "An empty page must belong to the free page run set"; 1771 size_t fpr_size = fpr->ByteSize(this); 1772 CHECK_ALIGNED(fpr_size, kPageSize) 1773 << "A free page run size isn't page-aligned : " << fpr_size; 1774 size_t num_pages = fpr_size / kPageSize; 1775 CHECK_GT(num_pages, static_cast<uintptr_t>(0)) 1776 << "A free page run size must be > 0 : " << fpr_size; 1777 for (size_t j = i + 1; j < i + num_pages; ++j) { 1778 CHECK(IsFreePage(j)) 1779 << "A mismatch between the page map table for kPageMapEmpty " 1780 << " at page index " << j 1781 << " and the free page run size : page index range : " 1782 << i << " to " << (i + num_pages) << std::endl << DumpPageMap(); 1783 } 1784 i += num_pages; 1785 CHECK_LE(i, pm_end) << "Page map index " << i << " out of range < " << pm_end 1786 << std::endl << DumpPageMap(); 1787 break; 1788 } 1789 case kPageMapLargeObject: { 1790 // The start of a large object. 1791 size_t num_pages = 1; 1792 size_t idx = i + 1; 1793 while (idx < pm_end && page_map_[idx] == kPageMapLargeObjectPart) { 1794 num_pages++; 1795 idx++; 1796 } 1797 uint8_t* start = base_ + i * kPageSize; 1798 if (is_running_on_memory_tool_) { 1799 start += ::art::gc::space::kDefaultMemoryToolRedZoneBytes; 1800 } 1801 mirror::Object* obj = reinterpret_cast<mirror::Object*>(start); 1802 size_t obj_size = obj->SizeOf(); 1803 CHECK_GT(obj_size + memory_tool_modifier, kLargeSizeThreshold) 1804 << "A rosalloc large object size must be > " << kLargeSizeThreshold; 1805 CHECK_EQ(num_pages, RoundUp(obj_size + memory_tool_modifier, kPageSize) / kPageSize) 1806 << "A rosalloc large object size " << obj_size + memory_tool_modifier 1807 << " does not match the page map table " << (num_pages * kPageSize) 1808 << std::endl << DumpPageMap(); 1809 i += num_pages; 1810 CHECK_LE(i, pm_end) << "Page map index " << i << " out of range < " << pm_end 1811 << std::endl << DumpPageMap(); 1812 break; 1813 } 1814 case kPageMapLargeObjectPart: 1815 LOG(FATAL) << "Unreachable - page map type: " << static_cast<int>(pm) << std::endl << DumpPageMap(); 1816 break; 1817 case kPageMapRun: { 1818 // The start of a run. 1819 Run* run = reinterpret_cast<Run*>(base_ + i * kPageSize); 1820 DCHECK_EQ(run->magic_num_, kMagicNum); 1821 size_t idx = run->size_bracket_idx_; 1822 CHECK_LT(idx, kNumOfSizeBrackets) << "Out of range size bracket index : " << idx; 1823 size_t num_pages = numOfPages[idx]; 1824 CHECK_GT(num_pages, static_cast<uintptr_t>(0)) 1825 << "Run size must be > 0 : " << num_pages; 1826 for (size_t j = i + 1; j < i + num_pages; ++j) { 1827 CHECK_EQ(page_map_[j], kPageMapRunPart) 1828 << "A mismatch between the page map table for kPageMapRunPart " 1829 << " at page index " << j 1830 << " and the run size : page index range " << i << " to " << (i + num_pages) 1831 << std::endl << DumpPageMap(); 1832 } 1833 // Don't verify the dedicated_full_run_ since it doesn't have any real allocations. 1834 runs.push_back(run); 1835 i += num_pages; 1836 CHECK_LE(i, pm_end) << "Page map index " << i << " out of range < " << pm_end 1837 << std::endl << DumpPageMap(); 1838 break; 1839 } 1840 case kPageMapRunPart: 1841 // Fall-through. 1842 default: 1843 LOG(FATAL) << "Unreachable - page map type: " << static_cast<int>(pm) << std::endl << DumpPageMap(); 1844 break; 1845 } 1846 } 1847 } 1848 std::list<Thread*> threads = Runtime::Current()->GetThreadList()->GetList(); 1849 for (Thread* thread : threads) { 1850 for (size_t i = 0; i < kNumThreadLocalSizeBrackets; ++i) { 1851 MutexLock brackets_mu(self, *size_bracket_locks_[i]); 1852 Run* thread_local_run = reinterpret_cast<Run*>(thread->GetRosAllocRun(i)); 1853 CHECK(thread_local_run != nullptr); 1854 CHECK(thread_local_run->IsThreadLocal()); 1855 CHECK(thread_local_run == dedicated_full_run_ || 1856 thread_local_run->size_bracket_idx_ == i); 1857 } 1858 } 1859 for (size_t i = 0; i < kNumOfSizeBrackets; i++) { 1860 MutexLock brackets_mu(self, *size_bracket_locks_[i]); 1861 Run* current_run = current_runs_[i]; 1862 CHECK(current_run != nullptr); 1863 if (current_run != dedicated_full_run_) { 1864 // The dedicated full run is currently marked as thread local. 1865 CHECK(!current_run->IsThreadLocal()); 1866 CHECK_EQ(current_run->size_bracket_idx_, i); 1867 } 1868 } 1869 // Call Verify() here for the lock order. 1870 for (auto& run : runs) { 1871 run->Verify(self, this, is_running_on_memory_tool_); 1872 } 1873 } 1874 1875 void RosAlloc::Run::Verify(Thread* self, RosAlloc* rosalloc, bool running_on_memory_tool) { 1876 DCHECK_EQ(magic_num_, kMagicNum) << "Bad magic number : " << Dump(); 1877 const size_t idx = size_bracket_idx_; 1878 CHECK_LT(idx, kNumOfSizeBrackets) << "Out of range size bracket index : " << Dump(); 1879 uint8_t* slot_base = reinterpret_cast<uint8_t*>(this) + headerSizes[idx]; 1880 const size_t num_slots = numOfSlots[idx]; 1881 size_t bracket_size = IndexToBracketSize(idx); 1882 CHECK_EQ(slot_base + num_slots * bracket_size, 1883 reinterpret_cast<uint8_t*>(this) + numOfPages[idx] * kPageSize) 1884 << "Mismatch in the end address of the run " << Dump(); 1885 // Check that the bulk free list is empty. It's only used during BulkFree(). 1886 CHECK(IsBulkFreeListEmpty()) << "The bulk free isn't empty " << Dump(); 1887 // Check the thread local runs, the current runs, and the run sets. 1888 if (IsThreadLocal()) { 1889 // If it's a thread local run, then it must be pointed to by an owner thread. 1890 bool owner_found = false; 1891 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 1892 for (auto it = thread_list.begin(); it != thread_list.end(); ++it) { 1893 Thread* thread = *it; 1894 for (size_t i = 0; i < kNumThreadLocalSizeBrackets; i++) { 1895 MutexLock mu(self, *rosalloc->size_bracket_locks_[i]); 1896 Run* thread_local_run = reinterpret_cast<Run*>(thread->GetRosAllocRun(i)); 1897 if (thread_local_run == this) { 1898 CHECK(!owner_found) 1899 << "A thread local run has more than one owner thread " << Dump(); 1900 CHECK_EQ(i, idx) 1901 << "A mismatching size bracket index in a thread local run " << Dump(); 1902 owner_found = true; 1903 } 1904 } 1905 } 1906 CHECK(owner_found) << "A thread local run has no owner thread " << Dump(); 1907 } else { 1908 // If it's not thread local, check that the thread local free list is empty. 1909 CHECK(IsThreadLocalFreeListEmpty()) 1910 << "A non-thread-local run's thread local free list isn't empty " 1911 << Dump(); 1912 // Check if it's a current run for the size bracket. 1913 bool is_current_run = false; 1914 for (size_t i = 0; i < kNumOfSizeBrackets; i++) { 1915 MutexLock mu(self, *rosalloc->size_bracket_locks_[i]); 1916 Run* current_run = rosalloc->current_runs_[i]; 1917 if (idx == i) { 1918 if (this == current_run) { 1919 is_current_run = true; 1920 } 1921 } else { 1922 // If the size bucket index does not match, then it must not 1923 // be a current run. 1924 CHECK_NE(this, current_run) 1925 << "A current run points to a run with a wrong size bracket index " << Dump(); 1926 } 1927 } 1928 // If it's neither a thread local or current run, then it must be 1929 // in a run set. 1930 if (!is_current_run) { 1931 MutexLock mu(self, rosalloc->lock_); 1932 auto& non_full_runs = rosalloc->non_full_runs_[idx]; 1933 // If it's all free, it must be a free page run rather than a run. 1934 CHECK(!IsAllFree()) << "A free run must be in a free page run set " << Dump(); 1935 if (!IsFull()) { 1936 // If it's not full, it must in the non-full run set. 1937 CHECK(non_full_runs.find(this) != non_full_runs.end()) 1938 << "A non-full run isn't in the non-full run set " << Dump(); 1939 } else { 1940 // If it's full, it must in the full run set (debug build only.) 1941 if (kIsDebugBuild) { 1942 auto& full_runs = rosalloc->full_runs_[idx]; 1943 CHECK(full_runs.find(this) != full_runs.end()) 1944 << " A full run isn't in the full run set " << Dump(); 1945 } 1946 } 1947 } 1948 } 1949 // Check each slot. 1950 size_t memory_tool_modifier = running_on_memory_tool ? 1951 2 * ::art::gc::space::kDefaultMemoryToolRedZoneBytes : 1952 0U; 1953 // TODO: reuse InspectAllSlots(). 1954 std::unique_ptr<bool[]> is_free(new bool[num_slots]()); // zero initialized 1955 // Mark the free slots and the remaining ones are allocated. 1956 for (Slot* slot = free_list_.Head(); slot != nullptr; slot = slot->Next()) { 1957 size_t slot_idx = SlotIndex(slot); 1958 DCHECK_LT(slot_idx, num_slots); 1959 is_free[slot_idx] = true; 1960 } 1961 if (IsThreadLocal()) { 1962 for (Slot* slot = thread_local_free_list_.Head(); slot != nullptr; slot = slot->Next()) { 1963 size_t slot_idx = SlotIndex(slot); 1964 DCHECK_LT(slot_idx, num_slots); 1965 is_free[slot_idx] = true; 1966 } 1967 } 1968 for (size_t slot_idx = 0; slot_idx < num_slots; ++slot_idx) { 1969 uint8_t* slot_addr = slot_base + slot_idx * bracket_size; 1970 if (running_on_memory_tool) { 1971 slot_addr += ::art::gc::space::kDefaultMemoryToolRedZoneBytes; 1972 } 1973 if (!is_free[slot_idx]) { 1974 // The slot is allocated 1975 mirror::Object* obj = reinterpret_cast<mirror::Object*>(slot_addr); 1976 size_t obj_size = obj->SizeOf(); 1977 CHECK_LE(obj_size + memory_tool_modifier, kLargeSizeThreshold) 1978 << "A run slot contains a large object " << Dump(); 1979 CHECK_EQ(SizeToIndex(obj_size + memory_tool_modifier), idx) 1980 << PrettyTypeOf(obj) << " " 1981 << "obj_size=" << obj_size << "(" << obj_size + memory_tool_modifier << "), idx=" << idx 1982 << " A run slot contains an object with wrong size " << Dump(); 1983 } 1984 } 1985 } 1986 1987 size_t RosAlloc::ReleasePages() { 1988 VLOG(heap) << "RosAlloc::ReleasePages()"; 1989 DCHECK(!DoesReleaseAllPages()); 1990 Thread* self = Thread::Current(); 1991 size_t reclaimed_bytes = 0; 1992 size_t i = 0; 1993 // Check the page map size which might have changed due to grow/shrink. 1994 while (i < page_map_size_) { 1995 // Reading the page map without a lock is racy but the race is benign since it should only 1996 // result in occasionally not releasing pages which we could release. 1997 uint8_t pm = page_map_[i]; 1998 switch (pm) { 1999 case kPageMapReleased: 2000 // Fall through. 2001 case kPageMapEmpty: { 2002 // This is currently the start of a free page run. 2003 // Acquire the lock to prevent other threads racing in and modifying the page map. 2004 MutexLock mu(self, lock_); 2005 // Check that it's still empty after we acquired the lock since another thread could have 2006 // raced in and placed an allocation here. 2007 if (IsFreePage(i)) { 2008 // Free page runs can start with a released page if we coalesced a released page free 2009 // page run with an empty page run. 2010 FreePageRun* fpr = reinterpret_cast<FreePageRun*>(base_ + i * kPageSize); 2011 // There is a race condition where FreePage can coalesce fpr with the previous 2012 // free page run before we acquire lock_. In that case free_page_runs_.find will not find 2013 // a run starting at fpr. To handle this race, we skip reclaiming the page range and go 2014 // to the next page. 2015 if (free_page_runs_.find(fpr) != free_page_runs_.end()) { 2016 size_t fpr_size = fpr->ByteSize(this); 2017 DCHECK_ALIGNED(fpr_size, kPageSize); 2018 uint8_t* start = reinterpret_cast<uint8_t*>(fpr); 2019 reclaimed_bytes += ReleasePageRange(start, start + fpr_size); 2020 size_t pages = fpr_size / kPageSize; 2021 CHECK_GT(pages, 0U) << "Infinite loop probable"; 2022 i += pages; 2023 DCHECK_LE(i, page_map_size_); 2024 break; 2025 } 2026 } 2027 FALLTHROUGH_INTENDED; 2028 } 2029 case kPageMapLargeObject: // Fall through. 2030 case kPageMapLargeObjectPart: // Fall through. 2031 case kPageMapRun: // Fall through. 2032 case kPageMapRunPart: // Fall through. 2033 ++i; 2034 break; // Skip. 2035 default: 2036 LOG(FATAL) << "Unreachable - page map type: " << static_cast<int>(pm); 2037 break; 2038 } 2039 } 2040 return reclaimed_bytes; 2041 } 2042 2043 size_t RosAlloc::ReleasePageRange(uint8_t* start, uint8_t* end) { 2044 DCHECK_ALIGNED(start, kPageSize); 2045 DCHECK_ALIGNED(end, kPageSize); 2046 DCHECK_LT(start, end); 2047 if (kIsDebugBuild) { 2048 // In the debug build, the first page of a free page run 2049 // contains a magic number for debugging. Exclude it. 2050 start += kPageSize; 2051 2052 // Single pages won't be released. 2053 if (start == end) { 2054 return 0; 2055 } 2056 } 2057 if (!kMadviseZeroes) { 2058 // TODO: Do this when we resurrect the page instead. 2059 memset(start, 0, end - start); 2060 } 2061 CHECK_EQ(madvise(start, end - start, MADV_DONTNEED), 0); 2062 size_t pm_idx = ToPageMapIndex(start); 2063 size_t reclaimed_bytes = 0; 2064 // Calculate reclaimed bytes and upate page map. 2065 const size_t max_idx = pm_idx + (end - start) / kPageSize; 2066 for (; pm_idx < max_idx; ++pm_idx) { 2067 DCHECK(IsFreePage(pm_idx)); 2068 if (page_map_[pm_idx] == kPageMapEmpty) { 2069 // Mark the page as released and update how many bytes we released. 2070 reclaimed_bytes += kPageSize; 2071 page_map_[pm_idx] = kPageMapReleased; 2072 } 2073 } 2074 return reclaimed_bytes; 2075 } 2076 2077 void RosAlloc::LogFragmentationAllocFailure(std::ostream& os, size_t failed_alloc_bytes) { 2078 Thread* self = Thread::Current(); 2079 size_t largest_continuous_free_pages = 0; 2080 WriterMutexLock wmu(self, bulk_free_lock_); 2081 MutexLock mu(self, lock_); 2082 for (FreePageRun* fpr : free_page_runs_) { 2083 largest_continuous_free_pages = std::max(largest_continuous_free_pages, 2084 fpr->ByteSize(this)); 2085 } 2086 if (failed_alloc_bytes > kLargeSizeThreshold) { 2087 // Large allocation. 2088 size_t required_bytes = RoundUp(failed_alloc_bytes, kPageSize); 2089 if (required_bytes > largest_continuous_free_pages) { 2090 os << "; failed due to fragmentation (required continguous free " 2091 << required_bytes << " bytes where largest contiguous free " 2092 << largest_continuous_free_pages << " bytes)"; 2093 } 2094 } else { 2095 // Non-large allocation. 2096 size_t required_bytes = numOfPages[SizeToIndex(failed_alloc_bytes)] * kPageSize; 2097 if (required_bytes > largest_continuous_free_pages) { 2098 os << "; failed due to fragmentation (required continguous free " 2099 << required_bytes << " bytes for a new buffer where largest contiguous free " 2100 << largest_continuous_free_pages << " bytes)"; 2101 } 2102 } 2103 } 2104 2105 void RosAlloc::DumpStats(std::ostream& os) { 2106 Thread* self = Thread::Current(); 2107 CHECK(Locks::mutator_lock_->IsExclusiveHeld(self)) 2108 << "The mutator locks isn't exclusively locked at " << __PRETTY_FUNCTION__; 2109 size_t num_large_objects = 0; 2110 size_t num_pages_large_objects = 0; 2111 // These arrays are zero initialized. 2112 std::unique_ptr<size_t[]> num_runs(new size_t[kNumOfSizeBrackets]()); 2113 std::unique_ptr<size_t[]> num_pages_runs(new size_t[kNumOfSizeBrackets]()); 2114 std::unique_ptr<size_t[]> num_slots(new size_t[kNumOfSizeBrackets]()); 2115 std::unique_ptr<size_t[]> num_used_slots(new size_t[kNumOfSizeBrackets]()); 2116 std::unique_ptr<size_t[]> num_metadata_bytes(new size_t[kNumOfSizeBrackets]()); 2117 ReaderMutexLock rmu(self, bulk_free_lock_); 2118 MutexLock lock_mu(self, lock_); 2119 for (size_t i = 0; i < page_map_size_; ) { 2120 uint8_t pm = page_map_[i]; 2121 switch (pm) { 2122 case kPageMapReleased: 2123 case kPageMapEmpty: 2124 ++i; 2125 break; 2126 case kPageMapLargeObject: { 2127 size_t num_pages = 1; 2128 size_t idx = i + 1; 2129 while (idx < page_map_size_ && page_map_[idx] == kPageMapLargeObjectPart) { 2130 num_pages++; 2131 idx++; 2132 } 2133 num_large_objects++; 2134 num_pages_large_objects += num_pages; 2135 i += num_pages; 2136 break; 2137 } 2138 case kPageMapLargeObjectPart: 2139 LOG(FATAL) << "Unreachable - page map type: " << static_cast<int>(pm) << std::endl 2140 << DumpPageMap(); 2141 break; 2142 case kPageMapRun: { 2143 Run* run = reinterpret_cast<Run*>(base_ + i * kPageSize); 2144 size_t idx = run->size_bracket_idx_; 2145 size_t num_pages = numOfPages[idx]; 2146 num_runs[idx]++; 2147 num_pages_runs[idx] += num_pages; 2148 num_slots[idx] += numOfSlots[idx]; 2149 size_t num_free_slots = run->NumberOfFreeSlots(); 2150 num_used_slots[idx] += numOfSlots[idx] - num_free_slots; 2151 num_metadata_bytes[idx] += headerSizes[idx]; 2152 i += num_pages; 2153 break; 2154 } 2155 case kPageMapRunPart: 2156 // Fall-through. 2157 default: 2158 LOG(FATAL) << "Unreachable - page map type: " << static_cast<int>(pm) << std::endl 2159 << DumpPageMap(); 2160 break; 2161 } 2162 } 2163 os << "RosAlloc stats:\n"; 2164 for (size_t i = 0; i < kNumOfSizeBrackets; ++i) { 2165 os << "Bracket " << i << " (" << bracketSizes[i] << "):" 2166 << " #runs=" << num_runs[i] 2167 << " #pages=" << num_pages_runs[i] 2168 << " (" << PrettySize(num_pages_runs[i] * kPageSize) << ")" 2169 << " #metadata_bytes=" << PrettySize(num_metadata_bytes[i]) 2170 << " #slots=" << num_slots[i] << " (" << PrettySize(num_slots[i] * bracketSizes[i]) << ")" 2171 << " #used_slots=" << num_used_slots[i] 2172 << " (" << PrettySize(num_used_slots[i] * bracketSizes[i]) << ")\n"; 2173 } 2174 os << "Large #allocations=" << num_large_objects 2175 << " #pages=" << num_pages_large_objects 2176 << " (" << PrettySize(num_pages_large_objects * kPageSize) << ")\n"; 2177 size_t total_num_pages = 0; 2178 size_t total_metadata_bytes = 0; 2179 size_t total_allocated_bytes = 0; 2180 for (size_t i = 0; i < kNumOfSizeBrackets; ++i) { 2181 total_num_pages += num_pages_runs[i]; 2182 total_metadata_bytes += num_metadata_bytes[i]; 2183 total_allocated_bytes += num_used_slots[i] * bracketSizes[i]; 2184 } 2185 total_num_pages += num_pages_large_objects; 2186 total_allocated_bytes += num_pages_large_objects * kPageSize; 2187 os << "Total #total_bytes=" << PrettySize(total_num_pages * kPageSize) 2188 << " #metadata_bytes=" << PrettySize(total_metadata_bytes) 2189 << " #used_bytes=" << PrettySize(total_allocated_bytes) << "\n"; 2190 os << "\n"; 2191 } 2192 2193 } // namespace allocator 2194 } // namespace gc 2195 } // namespace art 2196