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| 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 #include "net/disk_cache/rankings.h" | |
| 6 | |
| 7 #include "base/metrics/histogram.h" | |
| 8 #include "net/disk_cache/backend_impl.h" | |
| 9 #include "net/disk_cache/disk_format.h" | |
| 10 #include "net/disk_cache/entry_impl.h" | |
| 11 #include "net/disk_cache/errors.h" | |
| 12 #include "net/disk_cache/stress_support.h" | |
| 13 | |
| 14 // Define BLOCKFILE_BACKEND_IMPL_OBJ to be a disk_cache::BackendImpl* in order | |
| 15 // to use the CACHE_UMA histogram macro. | |
| 16 #define BLOCKFILE_BACKEND_IMPL_OBJ backend_ | |
| 17 #include "net/disk_cache/histogram_macros.h" | |
| 18 | |
| 19 using base::Time; | |
| 20 using base::TimeTicks; | |
| 21 | |
| 22 namespace disk_cache { | |
| 23 // This is used by crash_cache.exe to generate unit test files. | |
| 24 NET_EXPORT_PRIVATE RankCrashes g_rankings_crash = NO_CRASH; | |
| 25 } | |
| 26 | |
| 27 namespace { | |
| 28 | |
| 29 enum Operation { | |
| 30 INSERT = 1, | |
| 31 REMOVE | |
| 32 }; | |
| 33 | |
| 34 // This class provides a simple lock for the LRU list of rankings. Whenever an | |
| 35 // entry is to be inserted or removed from the list, a transaction object should | |
| 36 // be created to keep track of the operation. If the process crashes before | |
| 37 // finishing the operation, the transaction record (stored as part of the user | |
| 38 // data on the file header) can be used to finish the operation. | |
| 39 class Transaction { | |
| 40 public: | |
| 41 // addr is the cache addres of the node being inserted or removed. We want to | |
| 42 // avoid having the compiler doing optimizations on when to read or write | |
| 43 // from user_data because it is the basis of the crash detection. Maybe | |
| 44 // volatile is not enough for that, but it should be a good hint. | |
| 45 Transaction(volatile disk_cache::LruData* data, disk_cache::Addr addr, | |
| 46 Operation op, int list); | |
| 47 ~Transaction(); | |
| 48 private: | |
| 49 volatile disk_cache::LruData* data_; | |
| 50 DISALLOW_COPY_AND_ASSIGN(Transaction); | |
| 51 }; | |
| 52 | |
| 53 Transaction::Transaction(volatile disk_cache::LruData* data, | |
| 54 disk_cache::Addr addr, Operation op, int list) | |
| 55 : data_(data) { | |
| 56 DCHECK(!data_->transaction); | |
| 57 DCHECK(addr.is_initialized()); | |
| 58 data_->operation = op; | |
| 59 data_->operation_list = list; | |
| 60 data_->transaction = addr.value(); | |
| 61 } | |
| 62 | |
| 63 Transaction::~Transaction() { | |
| 64 DCHECK(data_->transaction); | |
| 65 data_->transaction = 0; | |
| 66 data_->operation = 0; | |
| 67 data_->operation_list = 0; | |
| 68 } | |
| 69 | |
| 70 // Code locations that can generate crashes. | |
| 71 enum CrashLocation { | |
| 72 ON_INSERT_1, ON_INSERT_2, ON_INSERT_3, ON_INSERT_4, ON_REMOVE_1, ON_REMOVE_2, | |
| 73 ON_REMOVE_3, ON_REMOVE_4, ON_REMOVE_5, ON_REMOVE_6, ON_REMOVE_7, ON_REMOVE_8 | |
| 74 }; | |
| 75 | |
| 76 #ifndef NDEBUG | |
| 77 void TerminateSelf() { | |
| 78 #if defined(OS_WIN) | |
| 79 // Windows does more work on _exit() than we would like, so we force exit. | |
| 80 TerminateProcess(GetCurrentProcess(), 0); | |
| 81 #elif defined(OS_POSIX) | |
| 82 // On POSIX, _exit() will terminate the process with minimal cleanup, | |
| 83 // and it is cleaner than killing. | |
| 84 _exit(0); | |
| 85 #endif | |
| 86 } | |
| 87 #endif // NDEBUG | |
| 88 | |
| 89 // Generates a crash on debug builds, acording to the value of g_rankings_crash. | |
| 90 // This used by crash_cache.exe to generate unit-test files. | |
| 91 void GenerateCrash(CrashLocation location) { | |
| 92 #ifndef NDEBUG | |
| 93 if (disk_cache::NO_CRASH == disk_cache::g_rankings_crash) | |
| 94 return; | |
| 95 switch (location) { | |
| 96 case ON_INSERT_1: | |
| 97 switch (disk_cache::g_rankings_crash) { | |
| 98 case disk_cache::INSERT_ONE_1: | |
| 99 case disk_cache::INSERT_LOAD_1: | |
| 100 TerminateSelf(); | |
| 101 default: | |
| 102 break; | |
| 103 } | |
| 104 break; | |
| 105 case ON_INSERT_2: | |
| 106 if (disk_cache::INSERT_EMPTY_1 == disk_cache::g_rankings_crash) | |
| 107 TerminateSelf(); | |
| 108 break; | |
| 109 case ON_INSERT_3: | |
| 110 switch (disk_cache::g_rankings_crash) { | |
| 111 case disk_cache::INSERT_EMPTY_2: | |
| 112 case disk_cache::INSERT_ONE_2: | |
| 113 case disk_cache::INSERT_LOAD_2: | |
| 114 TerminateSelf(); | |
| 115 default: | |
| 116 break; | |
| 117 } | |
| 118 break; | |
| 119 case ON_INSERT_4: | |
| 120 switch (disk_cache::g_rankings_crash) { | |
| 121 case disk_cache::INSERT_EMPTY_3: | |
| 122 case disk_cache::INSERT_ONE_3: | |
| 123 TerminateSelf(); | |
| 124 default: | |
| 125 break; | |
| 126 } | |
| 127 break; | |
| 128 case ON_REMOVE_1: | |
| 129 switch (disk_cache::g_rankings_crash) { | |
| 130 case disk_cache::REMOVE_ONE_1: | |
| 131 case disk_cache::REMOVE_HEAD_1: | |
| 132 case disk_cache::REMOVE_TAIL_1: | |
| 133 case disk_cache::REMOVE_LOAD_1: | |
| 134 TerminateSelf(); | |
| 135 default: | |
| 136 break; | |
| 137 } | |
| 138 break; | |
| 139 case ON_REMOVE_2: | |
| 140 if (disk_cache::REMOVE_ONE_2 == disk_cache::g_rankings_crash) | |
| 141 TerminateSelf(); | |
| 142 break; | |
| 143 case ON_REMOVE_3: | |
| 144 if (disk_cache::REMOVE_ONE_3 == disk_cache::g_rankings_crash) | |
| 145 TerminateSelf(); | |
| 146 break; | |
| 147 case ON_REMOVE_4: | |
| 148 if (disk_cache::REMOVE_HEAD_2 == disk_cache::g_rankings_crash) | |
| 149 TerminateSelf(); | |
| 150 break; | |
| 151 case ON_REMOVE_5: | |
| 152 if (disk_cache::REMOVE_TAIL_2 == disk_cache::g_rankings_crash) | |
| 153 TerminateSelf(); | |
| 154 break; | |
| 155 case ON_REMOVE_6: | |
| 156 if (disk_cache::REMOVE_TAIL_3 == disk_cache::g_rankings_crash) | |
| 157 TerminateSelf(); | |
| 158 break; | |
| 159 case ON_REMOVE_7: | |
| 160 switch (disk_cache::g_rankings_crash) { | |
| 161 case disk_cache::REMOVE_ONE_4: | |
| 162 case disk_cache::REMOVE_LOAD_2: | |
| 163 case disk_cache::REMOVE_HEAD_3: | |
| 164 TerminateSelf(); | |
| 165 default: | |
| 166 break; | |
| 167 } | |
| 168 break; | |
| 169 case ON_REMOVE_8: | |
| 170 switch (disk_cache::g_rankings_crash) { | |
| 171 case disk_cache::REMOVE_HEAD_4: | |
| 172 case disk_cache::REMOVE_LOAD_3: | |
| 173 TerminateSelf(); | |
| 174 default: | |
| 175 break; | |
| 176 } | |
| 177 break; | |
| 178 default: | |
| 179 NOTREACHED(); | |
| 180 return; | |
| 181 } | |
| 182 #endif // NDEBUG | |
| 183 } | |
| 184 | |
| 185 // Update the timestamp fields of |node|. | |
| 186 void UpdateTimes(disk_cache::CacheRankingsBlock* node, bool modified) { | |
| 187 base::Time now = base::Time::Now(); | |
| 188 node->Data()->last_used = now.ToInternalValue(); | |
| 189 if (modified) | |
| 190 node->Data()->last_modified = now.ToInternalValue(); | |
| 191 } | |
| 192 | |
| 193 } // namespace | |
| 194 | |
| 195 namespace disk_cache { | |
| 196 | |
| 197 Rankings::ScopedRankingsBlock::ScopedRankingsBlock() : rankings_(NULL) {} | |
| 198 | |
| 199 Rankings::ScopedRankingsBlock::ScopedRankingsBlock(Rankings* rankings) | |
| 200 : rankings_(rankings) {} | |
| 201 | |
| 202 Rankings::ScopedRankingsBlock::ScopedRankingsBlock( | |
| 203 Rankings* rankings, CacheRankingsBlock* node) | |
| 204 : scoped_ptr<CacheRankingsBlock>(node), rankings_(rankings) {} | |
| 205 | |
| 206 Rankings::Iterator::Iterator(Rankings* rankings) { | |
| 207 memset(this, 0, sizeof(Iterator)); | |
| 208 my_rankings = rankings; | |
| 209 } | |
| 210 | |
| 211 Rankings::Iterator::~Iterator() { | |
| 212 for (int i = 0; i < 3; i++) | |
| 213 ScopedRankingsBlock(my_rankings, nodes[i]); | |
| 214 } | |
| 215 | |
| 216 Rankings::Rankings() : init_(false) {} | |
| 217 | |
| 218 Rankings::~Rankings() {} | |
| 219 | |
| 220 bool Rankings::Init(BackendImpl* backend, bool count_lists) { | |
| 221 DCHECK(!init_); | |
| 222 if (init_) | |
| 223 return false; | |
| 224 | |
| 225 backend_ = backend; | |
| 226 control_data_ = backend_->GetLruData(); | |
| 227 count_lists_ = count_lists; | |
| 228 | |
| 229 ReadHeads(); | |
| 230 ReadTails(); | |
| 231 | |
| 232 if (control_data_->transaction) | |
| 233 CompleteTransaction(); | |
| 234 | |
| 235 init_ = true; | |
| 236 return true; | |
| 237 } | |
| 238 | |
| 239 void Rankings::Reset() { | |
| 240 init_ = false; | |
| 241 for (int i = 0; i < LAST_ELEMENT; i++) { | |
| 242 heads_[i].set_value(0); | |
| 243 tails_[i].set_value(0); | |
| 244 } | |
| 245 control_data_ = NULL; | |
| 246 } | |
| 247 | |
| 248 void Rankings::Insert(CacheRankingsBlock* node, bool modified, List list) { | |
| 249 Trace("Insert 0x%x l %d", node->address().value(), list); | |
| 250 DCHECK(node->HasData()); | |
| 251 Addr& my_head = heads_[list]; | |
| 252 Addr& my_tail = tails_[list]; | |
| 253 Transaction lock(control_data_, node->address(), INSERT, list); | |
| 254 CacheRankingsBlock head(backend_->File(my_head), my_head); | |
| 255 if (my_head.is_initialized()) { | |
| 256 if (!GetRanking(&head)) | |
| 257 return; | |
| 258 | |
| 259 if (head.Data()->prev != my_head.value() && // Normal path. | |
| 260 head.Data()->prev != node->address().value()) { // FinishInsert(). | |
| 261 backend_->CriticalError(ERR_INVALID_LINKS); | |
| 262 return; | |
| 263 } | |
| 264 | |
| 265 head.Data()->prev = node->address().value(); | |
| 266 head.Store(); | |
| 267 GenerateCrash(ON_INSERT_1); | |
| 268 UpdateIterators(&head); | |
| 269 } | |
| 270 | |
| 271 node->Data()->next = my_head.value(); | |
| 272 node->Data()->prev = node->address().value(); | |
| 273 my_head.set_value(node->address().value()); | |
| 274 | |
| 275 if (!my_tail.is_initialized() || my_tail.value() == node->address().value()) { | |
| 276 my_tail.set_value(node->address().value()); | |
| 277 node->Data()->next = my_tail.value(); | |
| 278 WriteTail(list); | |
| 279 GenerateCrash(ON_INSERT_2); | |
| 280 } | |
| 281 | |
| 282 UpdateTimes(node, modified); | |
| 283 node->Store(); | |
| 284 GenerateCrash(ON_INSERT_3); | |
| 285 | |
| 286 // The last thing to do is move our head to point to a node already stored. | |
| 287 WriteHead(list); | |
| 288 IncrementCounter(list); | |
| 289 GenerateCrash(ON_INSERT_4); | |
| 290 backend_->FlushIndex(); | |
| 291 } | |
| 292 | |
| 293 // If a, b and r are elements on the list, and we want to remove r, the possible | |
| 294 // states for the objects if a crash happens are (where y(x, z) means for object | |
| 295 // y, prev is x and next is z): | |
| 296 // A. One element: | |
| 297 // 1. r(r, r), head(r), tail(r) initial state | |
| 298 // 2. r(r, r), head(0), tail(r) WriteHead() | |
| 299 // 3. r(r, r), head(0), tail(0) WriteTail() | |
| 300 // 4. r(0, 0), head(0), tail(0) next.Store() | |
| 301 // | |
| 302 // B. Remove a random element: | |
| 303 // 1. a(x, r), r(a, b), b(r, y), head(x), tail(y) initial state | |
| 304 // 2. a(x, r), r(a, b), b(a, y), head(x), tail(y) next.Store() | |
| 305 // 3. a(x, b), r(a, b), b(a, y), head(x), tail(y) prev.Store() | |
| 306 // 4. a(x, b), r(0, 0), b(a, y), head(x), tail(y) node.Store() | |
| 307 // | |
| 308 // C. Remove head: | |
| 309 // 1. r(r, b), b(r, y), head(r), tail(y) initial state | |
| 310 // 2. r(r, b), b(r, y), head(b), tail(y) WriteHead() | |
| 311 // 3. r(r, b), b(b, y), head(b), tail(y) next.Store() | |
| 312 // 4. r(0, 0), b(b, y), head(b), tail(y) prev.Store() | |
| 313 // | |
| 314 // D. Remove tail: | |
| 315 // 1. a(x, r), r(a, r), head(x), tail(r) initial state | |
| 316 // 2. a(x, r), r(a, r), head(x), tail(a) WriteTail() | |
| 317 // 3. a(x, a), r(a, r), head(x), tail(a) prev.Store() | |
| 318 // 4. a(x, a), r(0, 0), head(x), tail(a) next.Store() | |
| 319 void Rankings::Remove(CacheRankingsBlock* node, List list, bool strict) { | |
| 320 Trace("Remove 0x%x (0x%x 0x%x) l %d", node->address().value(), | |
| 321 node->Data()->next, node->Data()->prev, list); | |
| 322 DCHECK(node->HasData()); | |
| 323 if (strict) | |
| 324 InvalidateIterators(node); | |
| 325 | |
| 326 Addr next_addr(node->Data()->next); | |
| 327 Addr prev_addr(node->Data()->prev); | |
| 328 if (!next_addr.is_initialized() || next_addr.is_separate_file() || | |
| 329 !prev_addr.is_initialized() || prev_addr.is_separate_file()) { | |
| 330 if (next_addr.is_initialized() || prev_addr.is_initialized()) { | |
| 331 LOG(ERROR) << "Invalid rankings info."; | |
| 332 STRESS_NOTREACHED(); | |
| 333 } | |
| 334 return; | |
| 335 } | |
| 336 | |
| 337 CacheRankingsBlock next(backend_->File(next_addr), next_addr); | |
| 338 CacheRankingsBlock prev(backend_->File(prev_addr), prev_addr); | |
| 339 if (!GetRanking(&next) || !GetRanking(&prev)) { | |
| 340 STRESS_NOTREACHED(); | |
| 341 return; | |
| 342 } | |
| 343 | |
| 344 if (!CheckLinks(node, &prev, &next, &list)) | |
| 345 return; | |
| 346 | |
| 347 Transaction lock(control_data_, node->address(), REMOVE, list); | |
| 348 prev.Data()->next = next.address().value(); | |
| 349 next.Data()->prev = prev.address().value(); | |
| 350 GenerateCrash(ON_REMOVE_1); | |
| 351 | |
| 352 CacheAddr node_value = node->address().value(); | |
| 353 Addr& my_head = heads_[list]; | |
| 354 Addr& my_tail = tails_[list]; | |
| 355 if (node_value == my_head.value() || node_value == my_tail.value()) { | |
| 356 if (my_head.value() == my_tail.value()) { | |
| 357 my_head.set_value(0); | |
| 358 my_tail.set_value(0); | |
| 359 | |
| 360 WriteHead(list); | |
| 361 GenerateCrash(ON_REMOVE_2); | |
| 362 WriteTail(list); | |
| 363 GenerateCrash(ON_REMOVE_3); | |
| 364 } else if (node_value == my_head.value()) { | |
| 365 my_head.set_value(next.address().value()); | |
| 366 next.Data()->prev = next.address().value(); | |
| 367 | |
| 368 WriteHead(list); | |
| 369 GenerateCrash(ON_REMOVE_4); | |
| 370 } else if (node_value == my_tail.value()) { | |
| 371 my_tail.set_value(prev.address().value()); | |
| 372 prev.Data()->next = prev.address().value(); | |
| 373 | |
| 374 WriteTail(list); | |
| 375 GenerateCrash(ON_REMOVE_5); | |
| 376 | |
| 377 // Store the new tail to make sure we can undo the operation if we crash. | |
| 378 prev.Store(); | |
| 379 GenerateCrash(ON_REMOVE_6); | |
| 380 } | |
| 381 } | |
| 382 | |
| 383 // Nodes out of the list can be identified by invalid pointers. | |
| 384 node->Data()->next = 0; | |
| 385 node->Data()->prev = 0; | |
| 386 | |
| 387 // The last thing to get to disk is the node itself, so before that there is | |
| 388 // enough info to recover. | |
| 389 next.Store(); | |
| 390 GenerateCrash(ON_REMOVE_7); | |
| 391 prev.Store(); | |
| 392 GenerateCrash(ON_REMOVE_8); | |
| 393 node->Store(); | |
| 394 DecrementCounter(list); | |
| 395 UpdateIterators(&next); | |
| 396 UpdateIterators(&prev); | |
| 397 backend_->FlushIndex(); | |
| 398 } | |
| 399 | |
| 400 // A crash in between Remove and Insert will lead to a dirty entry not on the | |
| 401 // list. We want to avoid that case as much as we can (as while waiting for IO), | |
| 402 // but the net effect is just an assert on debug when attempting to remove the | |
| 403 // entry. Otherwise we'll need reentrant transactions, which is an overkill. | |
| 404 void Rankings::UpdateRank(CacheRankingsBlock* node, bool modified, List list) { | |
| 405 Addr& my_head = heads_[list]; | |
| 406 if (my_head.value() == node->address().value()) { | |
| 407 UpdateTimes(node, modified); | |
| 408 node->set_modified(); | |
| 409 return; | |
| 410 } | |
| 411 | |
| 412 TimeTicks start = TimeTicks::Now(); | |
| 413 Remove(node, list, true); | |
| 414 Insert(node, modified, list); | |
| 415 CACHE_UMA(AGE_MS, "UpdateRank", 0, start); | |
| 416 } | |
| 417 | |
| 418 CacheRankingsBlock* Rankings::GetNext(CacheRankingsBlock* node, List list) { | |
| 419 ScopedRankingsBlock next(this); | |
| 420 if (!node) { | |
| 421 Addr& my_head = heads_[list]; | |
| 422 if (!my_head.is_initialized()) | |
| 423 return NULL; | |
| 424 next.reset(new CacheRankingsBlock(backend_->File(my_head), my_head)); | |
| 425 } else { | |
| 426 if (!node->HasData()) | |
| 427 node->Load(); | |
| 428 Addr& my_tail = tails_[list]; | |
| 429 if (!my_tail.is_initialized()) | |
| 430 return NULL; | |
| 431 if (my_tail.value() == node->address().value()) | |
| 432 return NULL; | |
| 433 Addr address(node->Data()->next); | |
| 434 if (address.value() == node->address().value()) | |
| 435 return NULL; // Another tail? fail it. | |
| 436 next.reset(new CacheRankingsBlock(backend_->File(address), address)); | |
| 437 } | |
| 438 | |
| 439 TrackRankingsBlock(next.get(), true); | |
| 440 | |
| 441 if (!GetRanking(next.get())) | |
| 442 return NULL; | |
| 443 | |
| 444 ConvertToLongLived(next.get()); | |
| 445 if (node && !CheckSingleLink(node, next.get())) | |
| 446 return NULL; | |
| 447 | |
| 448 return next.release(); | |
| 449 } | |
| 450 | |
| 451 CacheRankingsBlock* Rankings::GetPrev(CacheRankingsBlock* node, List list) { | |
| 452 ScopedRankingsBlock prev(this); | |
| 453 if (!node) { | |
| 454 Addr& my_tail = tails_[list]; | |
| 455 if (!my_tail.is_initialized()) | |
| 456 return NULL; | |
| 457 prev.reset(new CacheRankingsBlock(backend_->File(my_tail), my_tail)); | |
| 458 } else { | |
| 459 if (!node->HasData()) | |
| 460 node->Load(); | |
| 461 Addr& my_head = heads_[list]; | |
| 462 if (!my_head.is_initialized()) | |
| 463 return NULL; | |
| 464 if (my_head.value() == node->address().value()) | |
| 465 return NULL; | |
| 466 Addr address(node->Data()->prev); | |
| 467 if (address.value() == node->address().value()) | |
| 468 return NULL; // Another head? fail it. | |
| 469 prev.reset(new CacheRankingsBlock(backend_->File(address), address)); | |
| 470 } | |
| 471 | |
| 472 TrackRankingsBlock(prev.get(), true); | |
| 473 | |
| 474 if (!GetRanking(prev.get())) | |
| 475 return NULL; | |
| 476 | |
| 477 ConvertToLongLived(prev.get()); | |
| 478 if (node && !CheckSingleLink(prev.get(), node)) | |
| 479 return NULL; | |
| 480 | |
| 481 return prev.release(); | |
| 482 } | |
| 483 | |
| 484 void Rankings::FreeRankingsBlock(CacheRankingsBlock* node) { | |
| 485 TrackRankingsBlock(node, false); | |
| 486 } | |
| 487 | |
| 488 void Rankings::TrackRankingsBlock(CacheRankingsBlock* node, | |
| 489 bool start_tracking) { | |
| 490 if (!node) | |
| 491 return; | |
| 492 | |
| 493 IteratorPair current(node->address().value(), node); | |
| 494 | |
| 495 if (start_tracking) | |
| 496 iterators_.push_back(current); | |
| 497 else | |
| 498 iterators_.remove(current); | |
| 499 } | |
| 500 | |
| 501 int Rankings::SelfCheck() { | |
| 502 int total = 0; | |
| 503 int error = 0; | |
| 504 for (int i = 0; i < LAST_ELEMENT; i++) { | |
| 505 int partial = CheckList(static_cast<List>(i)); | |
| 506 if (partial < 0 && !error) | |
| 507 error = partial; | |
| 508 else if (partial > 0) | |
| 509 total += partial; | |
| 510 } | |
| 511 | |
| 512 return error ? error : total; | |
| 513 } | |
| 514 | |
| 515 bool Rankings::SanityCheck(CacheRankingsBlock* node, bool from_list) const { | |
| 516 if (!node->VerifyHash()) | |
| 517 return false; | |
| 518 | |
| 519 const RankingsNode* data = node->Data(); | |
| 520 | |
| 521 if ((!data->next && data->prev) || (data->next && !data->prev)) | |
| 522 return false; | |
| 523 | |
| 524 // Both pointers on zero is a node out of the list. | |
| 525 if (!data->next && !data->prev && from_list) | |
| 526 return false; | |
| 527 | |
| 528 List list = NO_USE; // Initialize it to something. | |
| 529 if ((node->address().value() == data->prev) && !IsHead(data->prev, &list)) | |
| 530 return false; | |
| 531 | |
| 532 if ((node->address().value() == data->next) && !IsTail(data->next, &list)) | |
| 533 return false; | |
| 534 | |
| 535 if (!data->next && !data->prev) | |
| 536 return true; | |
| 537 | |
| 538 Addr next_addr(data->next); | |
| 539 Addr prev_addr(data->prev); | |
| 540 if (!next_addr.SanityCheckV2() || next_addr.file_type() != RANKINGS || | |
| 541 !prev_addr.SanityCheckV2() || prev_addr.file_type() != RANKINGS) | |
| 542 return false; | |
| 543 | |
| 544 return true; | |
| 545 } | |
| 546 | |
| 547 bool Rankings::DataSanityCheck(CacheRankingsBlock* node, bool from_list) const { | |
| 548 const RankingsNode* data = node->Data(); | |
| 549 if (!data->contents) | |
| 550 return false; | |
| 551 | |
| 552 // It may have never been inserted. | |
| 553 if (from_list && (!data->last_used || !data->last_modified)) | |
| 554 return false; | |
| 555 | |
| 556 return true; | |
| 557 } | |
| 558 | |
| 559 void Rankings::SetContents(CacheRankingsBlock* node, CacheAddr address) { | |
| 560 node->Data()->contents = address; | |
| 561 node->Store(); | |
| 562 } | |
| 563 | |
| 564 void Rankings::ReadHeads() { | |
| 565 for (int i = 0; i < LAST_ELEMENT; i++) | |
| 566 heads_[i] = Addr(control_data_->heads[i]); | |
| 567 } | |
| 568 | |
| 569 void Rankings::ReadTails() { | |
| 570 for (int i = 0; i < LAST_ELEMENT; i++) | |
| 571 tails_[i] = Addr(control_data_->tails[i]); | |
| 572 } | |
| 573 | |
| 574 void Rankings::WriteHead(List list) { | |
| 575 control_data_->heads[list] = heads_[list].value(); | |
| 576 } | |
| 577 | |
| 578 void Rankings::WriteTail(List list) { | |
| 579 control_data_->tails[list] = tails_[list].value(); | |
| 580 } | |
| 581 | |
| 582 bool Rankings::GetRanking(CacheRankingsBlock* rankings) { | |
| 583 if (!rankings->address().is_initialized()) | |
| 584 return false; | |
| 585 | |
| 586 TimeTicks start = TimeTicks::Now(); | |
| 587 if (!rankings->Load()) | |
| 588 return false; | |
| 589 | |
| 590 if (!SanityCheck(rankings, true)) { | |
| 591 backend_->CriticalError(ERR_INVALID_LINKS); | |
| 592 return false; | |
| 593 } | |
| 594 | |
| 595 backend_->OnEvent(Stats::OPEN_RANKINGS); | |
| 596 | |
| 597 // Note that if the cache is in read_only mode, open entries are not marked | |
| 598 // as dirty, except when an entry is doomed. We have to look for open entries. | |
| 599 if (!backend_->read_only() && !rankings->Data()->dirty) | |
| 600 return true; | |
| 601 | |
| 602 EntryImpl* entry = backend_->GetOpenEntry(rankings); | |
| 603 if (!entry) { | |
| 604 if (backend_->read_only()) | |
| 605 return true; | |
| 606 | |
| 607 // We cannot trust this entry, but we cannot initiate a cleanup from this | |
| 608 // point (we may be in the middle of a cleanup already). The entry will be | |
| 609 // deleted when detected from a regular open/create path. | |
| 610 rankings->Data()->dirty = backend_->GetCurrentEntryId() - 1; | |
| 611 if (!rankings->Data()->dirty) | |
| 612 rankings->Data()->dirty--; | |
| 613 return true; | |
| 614 } | |
| 615 | |
| 616 // Note that we should not leave this module without deleting rankings first. | |
| 617 rankings->SetData(entry->rankings()->Data()); | |
| 618 | |
| 619 CACHE_UMA(AGE_MS, "GetRankings", 0, start); | |
| 620 return true; | |
| 621 } | |
| 622 | |
| 623 void Rankings::ConvertToLongLived(CacheRankingsBlock* rankings) { | |
| 624 if (rankings->own_data()) | |
| 625 return; | |
| 626 | |
| 627 // We cannot return a shared node because we are not keeping a reference | |
| 628 // to the entry that owns the buffer. Make this node a copy of the one that | |
| 629 // we have, and let the iterator logic update it when the entry changes. | |
| 630 CacheRankingsBlock temp(NULL, Addr(0)); | |
| 631 *temp.Data() = *rankings->Data(); | |
| 632 rankings->StopSharingData(); | |
| 633 *rankings->Data() = *temp.Data(); | |
| 634 } | |
| 635 | |
| 636 void Rankings::CompleteTransaction() { | |
| 637 Addr node_addr(static_cast<CacheAddr>(control_data_->transaction)); | |
| 638 if (!node_addr.is_initialized() || node_addr.is_separate_file()) { | |
| 639 NOTREACHED(); | |
| 640 LOG(ERROR) << "Invalid rankings info."; | |
| 641 return; | |
| 642 } | |
| 643 | |
| 644 Trace("CompleteTransaction 0x%x", node_addr.value()); | |
| 645 | |
| 646 CacheRankingsBlock node(backend_->File(node_addr), node_addr); | |
| 647 if (!node.Load()) | |
| 648 return; | |
| 649 | |
| 650 node.Store(); | |
| 651 | |
| 652 Addr& my_head = heads_[control_data_->operation_list]; | |
| 653 Addr& my_tail = tails_[control_data_->operation_list]; | |
| 654 | |
| 655 // We want to leave the node inside the list. The entry must me marked as | |
| 656 // dirty, and will be removed later. Otherwise, we'll get assertions when | |
| 657 // attempting to remove the dirty entry. | |
| 658 if (INSERT == control_data_->operation) { | |
| 659 Trace("FinishInsert h:0x%x t:0x%x", my_head.value(), my_tail.value()); | |
| 660 FinishInsert(&node); | |
| 661 } else if (REMOVE == control_data_->operation) { | |
| 662 Trace("RevertRemove h:0x%x t:0x%x", my_head.value(), my_tail.value()); | |
| 663 RevertRemove(&node); | |
| 664 } else { | |
| 665 NOTREACHED(); | |
| 666 LOG(ERROR) << "Invalid operation to recover."; | |
| 667 } | |
| 668 } | |
| 669 | |
| 670 void Rankings::FinishInsert(CacheRankingsBlock* node) { | |
| 671 control_data_->transaction = 0; | |
| 672 control_data_->operation = 0; | |
| 673 Addr& my_head = heads_[control_data_->operation_list]; | |
| 674 Addr& my_tail = tails_[control_data_->operation_list]; | |
| 675 if (my_head.value() != node->address().value()) { | |
| 676 if (my_tail.value() == node->address().value()) { | |
| 677 // This part will be skipped by the logic of Insert. | |
| 678 node->Data()->next = my_tail.value(); | |
| 679 } | |
| 680 | |
| 681 Insert(node, true, static_cast<List>(control_data_->operation_list)); | |
| 682 } | |
| 683 | |
| 684 // Tell the backend about this entry. | |
| 685 backend_->RecoveredEntry(node); | |
| 686 } | |
| 687 | |
| 688 void Rankings::RevertRemove(CacheRankingsBlock* node) { | |
| 689 Addr next_addr(node->Data()->next); | |
| 690 Addr prev_addr(node->Data()->prev); | |
| 691 if (!next_addr.is_initialized() || !prev_addr.is_initialized()) { | |
| 692 // The operation actually finished. Nothing to do. | |
| 693 control_data_->transaction = 0; | |
| 694 return; | |
| 695 } | |
| 696 if (next_addr.is_separate_file() || prev_addr.is_separate_file()) { | |
| 697 NOTREACHED(); | |
| 698 LOG(WARNING) << "Invalid rankings info."; | |
| 699 control_data_->transaction = 0; | |
| 700 return; | |
| 701 } | |
| 702 | |
| 703 CacheRankingsBlock next(backend_->File(next_addr), next_addr); | |
| 704 CacheRankingsBlock prev(backend_->File(prev_addr), prev_addr); | |
| 705 if (!next.Load() || !prev.Load()) | |
| 706 return; | |
| 707 | |
| 708 CacheAddr node_value = node->address().value(); | |
| 709 DCHECK(prev.Data()->next == node_value || | |
| 710 prev.Data()->next == prev_addr.value() || | |
| 711 prev.Data()->next == next.address().value()); | |
| 712 DCHECK(next.Data()->prev == node_value || | |
| 713 next.Data()->prev == next_addr.value() || | |
| 714 next.Data()->prev == prev.address().value()); | |
| 715 | |
| 716 if (node_value != prev_addr.value()) | |
| 717 prev.Data()->next = node_value; | |
| 718 if (node_value != next_addr.value()) | |
| 719 next.Data()->prev = node_value; | |
| 720 | |
| 721 List my_list = static_cast<List>(control_data_->operation_list); | |
| 722 Addr& my_head = heads_[my_list]; | |
| 723 Addr& my_tail = tails_[my_list]; | |
| 724 if (!my_head.is_initialized() || !my_tail.is_initialized()) { | |
| 725 my_head.set_value(node_value); | |
| 726 my_tail.set_value(node_value); | |
| 727 WriteHead(my_list); | |
| 728 WriteTail(my_list); | |
| 729 } else if (my_head.value() == next.address().value()) { | |
| 730 my_head.set_value(node_value); | |
| 731 prev.Data()->next = next.address().value(); | |
| 732 WriteHead(my_list); | |
| 733 } else if (my_tail.value() == prev.address().value()) { | |
| 734 my_tail.set_value(node_value); | |
| 735 next.Data()->prev = prev.address().value(); | |
| 736 WriteTail(my_list); | |
| 737 } | |
| 738 | |
| 739 next.Store(); | |
| 740 prev.Store(); | |
| 741 control_data_->transaction = 0; | |
| 742 control_data_->operation = 0; | |
| 743 backend_->FlushIndex(); | |
| 744 } | |
| 745 | |
| 746 bool Rankings::CheckLinks(CacheRankingsBlock* node, CacheRankingsBlock* prev, | |
| 747 CacheRankingsBlock* next, List* list) { | |
| 748 CacheAddr node_addr = node->address().value(); | |
| 749 if (prev->Data()->next == node_addr && | |
| 750 next->Data()->prev == node_addr) { | |
| 751 // A regular linked node. | |
| 752 return true; | |
| 753 } | |
| 754 | |
| 755 Trace("CheckLinks 0x%x (0x%x 0x%x)", node_addr, | |
| 756 prev->Data()->next, next->Data()->prev); | |
| 757 | |
| 758 if (node_addr != prev->address().value() && | |
| 759 node_addr != next->address().value() && | |
| 760 prev->Data()->next == next->address().value() && | |
| 761 next->Data()->prev == prev->address().value()) { | |
| 762 // The list is actually ok, node is wrong. | |
| 763 Trace("node 0x%x out of list %d", node_addr, list); | |
| 764 node->Data()->next = 0; | |
| 765 node->Data()->prev = 0; | |
| 766 node->Store(); | |
| 767 return false; | |
| 768 } | |
| 769 | |
| 770 if (prev->Data()->next == node_addr || | |
| 771 next->Data()->prev == node_addr) { | |
| 772 // Only one link is weird, lets double check. | |
| 773 if (prev->Data()->next != node_addr && IsHead(node_addr, list)) | |
| 774 return true; | |
| 775 | |
| 776 if (next->Data()->prev != node_addr && IsTail(node_addr, list)) | |
| 777 return true; | |
| 778 } | |
| 779 | |
| 780 LOG(ERROR) << "Inconsistent LRU."; | |
| 781 STRESS_NOTREACHED(); | |
| 782 | |
| 783 backend_->CriticalError(ERR_INVALID_LINKS); | |
| 784 return false; | |
| 785 } | |
| 786 | |
| 787 bool Rankings::CheckSingleLink(CacheRankingsBlock* prev, | |
| 788 CacheRankingsBlock* next) { | |
| 789 if (prev->Data()->next != next->address().value() || | |
| 790 next->Data()->prev != prev->address().value()) { | |
| 791 LOG(ERROR) << "Inconsistent LRU."; | |
| 792 | |
| 793 backend_->CriticalError(ERR_INVALID_LINKS); | |
| 794 return false; | |
| 795 } | |
| 796 | |
| 797 return true; | |
| 798 } | |
| 799 | |
| 800 int Rankings::CheckList(List list) { | |
| 801 Addr last1, last2; | |
| 802 int head_items; | |
| 803 int rv = CheckListSection(list, last1, last2, true, // Head to tail. | |
| 804 &last1, &last2, &head_items); | |
| 805 if (rv == ERR_NO_ERROR) | |
| 806 return head_items; | |
| 807 | |
| 808 return rv; | |
| 809 } | |
| 810 | |
| 811 // Note that the returned error codes assume a forward walk (from head to tail) | |
| 812 // so they have to be adjusted accordingly by the caller. We use two stop values | |
| 813 // to be able to detect a corrupt node at the end that is not linked going back. | |
| 814 int Rankings::CheckListSection(List list, Addr end1, Addr end2, bool forward, | |
| 815 Addr* last, Addr* second_last, int* num_items) { | |
| 816 Addr current = forward ? heads_[list] : tails_[list]; | |
| 817 *last = *second_last = current; | |
| 818 *num_items = 0; | |
| 819 if (!current.is_initialized()) | |
| 820 return ERR_NO_ERROR; | |
| 821 | |
| 822 if (!current.SanityCheckForRankings()) | |
| 823 return ERR_INVALID_HEAD; | |
| 824 | |
| 825 scoped_ptr<CacheRankingsBlock> node; | |
| 826 Addr prev_addr(current); | |
| 827 do { | |
| 828 node.reset(new CacheRankingsBlock(backend_->File(current), current)); | |
| 829 node->Load(); | |
| 830 if (!SanityCheck(node.get(), true)) | |
| 831 return ERR_INVALID_ENTRY; | |
| 832 | |
| 833 CacheAddr next = forward ? node->Data()->next : node->Data()->prev; | |
| 834 CacheAddr prev = forward ? node->Data()->prev : node->Data()->next; | |
| 835 | |
| 836 if (prev != prev_addr.value()) | |
| 837 return ERR_INVALID_PREV; | |
| 838 | |
| 839 Addr next_addr(next); | |
| 840 if (!next_addr.SanityCheckForRankings()) | |
| 841 return ERR_INVALID_NEXT; | |
| 842 | |
| 843 prev_addr = current; | |
| 844 current = next_addr; | |
| 845 *second_last = *last; | |
| 846 *last = current; | |
| 847 (*num_items)++; | |
| 848 | |
| 849 if (next_addr == prev_addr) { | |
| 850 Addr last = forward ? tails_[list] : heads_[list]; | |
| 851 if (next_addr == last) | |
| 852 return ERR_NO_ERROR; | |
| 853 return ERR_INVALID_TAIL; | |
| 854 } | |
| 855 } while (current != end1 && current != end2); | |
| 856 return ERR_NO_ERROR; | |
| 857 } | |
| 858 | |
| 859 bool Rankings::IsHead(CacheAddr addr, List* list) const { | |
| 860 for (int i = 0; i < LAST_ELEMENT; i++) { | |
| 861 if (addr == heads_[i].value()) { | |
| 862 if (*list != i) | |
| 863 Trace("Changing list %d to %d", *list, i); | |
| 864 *list = static_cast<List>(i); | |
| 865 return true; | |
| 866 } | |
| 867 } | |
| 868 return false; | |
| 869 } | |
| 870 | |
| 871 bool Rankings::IsTail(CacheAddr addr, List* list) const { | |
| 872 for (int i = 0; i < LAST_ELEMENT; i++) { | |
| 873 if (addr == tails_[i].value()) { | |
| 874 if (*list != i) | |
| 875 Trace("Changing list %d to %d", *list, i); | |
| 876 *list = static_cast<List>(i); | |
| 877 return true; | |
| 878 } | |
| 879 } | |
| 880 return false; | |
| 881 } | |
| 882 | |
| 883 // We expect to have just a few iterators at any given time, maybe two or three, | |
| 884 // But we could have more than one pointing at the same mode. We walk the list | |
| 885 // of cache iterators and update all that are pointing to the given node. | |
| 886 void Rankings::UpdateIterators(CacheRankingsBlock* node) { | |
| 887 CacheAddr address = node->address().value(); | |
| 888 for (IteratorList::iterator it = iterators_.begin(); it != iterators_.end(); | |
| 889 ++it) { | |
| 890 if (it->first == address && it->second->HasData()) { | |
| 891 CacheRankingsBlock* other = it->second; | |
| 892 *other->Data() = *node->Data(); | |
| 893 } | |
| 894 } | |
| 895 } | |
| 896 | |
| 897 void Rankings::InvalidateIterators(CacheRankingsBlock* node) { | |
| 898 CacheAddr address = node->address().value(); | |
| 899 for (IteratorList::iterator it = iterators_.begin(); it != iterators_.end(); | |
| 900 ++it) { | |
| 901 if (it->first == address) { | |
| 902 DLOG(INFO) << "Invalidating iterator at 0x" << std::hex << address; | |
| 903 it->second->Discard(); | |
| 904 } | |
| 905 } | |
| 906 } | |
| 907 | |
| 908 void Rankings::IncrementCounter(List list) { | |
| 909 if (!count_lists_) | |
| 910 return; | |
| 911 | |
| 912 DCHECK(control_data_->sizes[list] < kint32max); | |
| 913 if (control_data_->sizes[list] < kint32max) | |
| 914 control_data_->sizes[list]++; | |
| 915 } | |
| 916 | |
| 917 void Rankings::DecrementCounter(List list) { | |
| 918 if (!count_lists_) | |
| 919 return; | |
| 920 | |
| 921 DCHECK(control_data_->sizes[list] > 0); | |
| 922 if (control_data_->sizes[list] > 0) | |
| 923 control_data_->sizes[list]--; | |
| 924 } | |
| 925 | |
| 926 } // namespace disk_cache | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 121643003:
Reorganize net/disk_cache into backend specific directories. (Closed)
Base URL: svn://svn.chromium.org/chrome/trunk/src