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Overview
Comment: | Fix a race condition in the locking code that would sometimes cause SQLITE_PROTOCOL or SQLITE_CORRUPT to be returned when SQLITE_BUSY should have been returned. (CVS 326) |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
b0d218876442187af08161d989e6887b |
User & Date: | drh 2001-12-14 15:09:56.000 |
Context
2001-12-14
| ||
15:15 | Version 2.1.6 (CVS 455) (check-in: 6ecd90b6c3 user: drh tags: trunk) | |
15:09 | Fix a race condition in the locking code that would sometimes cause SQLITE_PROTOCOL or SQLITE_CORRUPT to be returned when SQLITE_BUSY should have been returned. (CVS 326) (check-in: b0d2188764 user: drh tags: trunk) | |
2001-12-06
| ||
13:30 | Version 2.1.5 (CVS 456) (check-in: 8e90ad552f user: drh tags: trunk) | |
Changes
Changes to VERSION.
|
| | | 1 | 2.1.6 |
Changes to src/btree.c.
1 2 3 4 5 6 7 8 9 10 11 | /* ** 2001 September 15 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* | | | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | /* ** 2001 September 15 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** $Id: btree.c,v 1.43 2001/12/14 15:09:57 drh Exp $ ** ** This file implements a external (disk-based) database using BTrees. ** For a detailed discussion of BTrees, refer to ** ** Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3: ** "Sorting And Searching", pages 473-480. Addison-Wesley ** Publishing Company, Reading, Massachusetts. |
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986 987 988 989 990 991 992 | amt -= a; zBuf += a; }else{ offset -= OVERFLOW_SIZE; } sqlitepager_unref(pOvfl); } | > | > > | 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 | amt -= a; zBuf += a; }else{ offset -= OVERFLOW_SIZE; } sqlitepager_unref(pOvfl); } if( amt>0 ){ return SQLITE_CORRUPT; } return SQLITE_OK; } /* ** Read part of the key associated with cursor pCur. A maximum ** of "amt" bytes will be transfered into zBuf[]. The transfer ** begins at "offset". The number of bytes actually read is ** returned. The amount returned will be smaller than the |
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Changes to src/os.c.
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104 105 106 107 108 109 110 | ** An instance of the following structure is allocated for each inode. ** A single inode can have multiple file descriptors, so each OsFile ** structure contains a pointer to an instance of this object and this ** object keeps a count of the number of OsFiles pointing to it. */ struct lockInfo { struct inodeKey key; /* The lookup key */ | | | 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 | ** An instance of the following structure is allocated for each inode. ** A single inode can have multiple file descriptors, so each OsFile ** structure contains a pointer to an instance of this object and this ** object keeps a count of the number of OsFiles pointing to it. */ struct lockInfo { struct inodeKey key; /* The lookup key */ int cnt; /* 0: unlocked. -1: write lock. 1...: read lock. */ int nRef; /* Number of pointers to this structure */ }; /* ** This hash table maps inodes (in the form of inodeKey structures) into ** pointers to lockInfo structures. */ |
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223 224 225 226 227 228 229 | /* ** Attempt to open a file for both reading and writing. If that ** fails, try opening it read-only. If the file does not exist, ** try to create it. ** | | | < | | | | | | | | | 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 | /* ** Attempt to open a file for both reading and writing. If that ** fails, try opening it read-only. If the file does not exist, ** try to create it. ** ** On success, a handle for the open file is written to *id ** and *pReadonly is set to 0 if the file was opened for reading and ** writing or 1 if the file was opened read-only. The function returns ** SQLITE_OK. ** ** On failure, the function returns SQLITE_CANTOPEN and leaves ** *pResulst and *pReadonly unchanged. */ int sqliteOsOpenReadWrite( const char *zFilename, OsFile *id, int *pReadonly ){ #if OS_UNIX id->fd = open(zFilename, O_RDWR|O_CREAT, 0644); if( id->fd<0 ){ id->fd = open(zFilename, O_RDONLY); if( id->fd<0 ){ return SQLITE_CANTOPEN; } *pReadonly = 1; }else{ *pReadonly = 0; } sqliteOsEnterMutex(); id->pLock = findLockInfo(id->fd); sqliteOsLeaveMutex(); if( id->pLock==0 ){ close(id->fd); return SQLITE_NOMEM; } id->locked = 0; return SQLITE_OK; #endif #if OS_WIN HANDLE h = CreateFile(zFilename, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, |
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283 284 285 286 287 288 289 | if( h==INVALID_HANDLE_VALUE ){ return SQLITE_CANTOPEN; } *pReadonly = 1; }else{ *pReadonly = 0; } | | > | | < | | | | | | | > | | < | | | | | | | > | 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 | if( h==INVALID_HANDLE_VALUE ){ return SQLITE_CANTOPEN; } *pReadonly = 1; }else{ *pReadonly = 0; } id->h = h; id->locked = 0; return SQLITE_OK; #endif } /* ** Attempt to open a new file for exclusive access by this process. ** The file will be opened for both reading and writing. To avoid ** a potential security problem, we do not allow the file to have ** previously existed. Nor do we allow the file to be a symbolic ** link. ** ** On success, write the file handle into *id and return SQLITE_OK. ** ** On failure, return SQLITE_CANTOPEN. */ int sqliteOsOpenExclusive(const char *zFilename, OsFile *id){ #if OS_UNIX if( access(zFilename, 0)==0 ){ return SQLITE_CANTOPEN; } #ifndef O_NOFOLLOW # define O_NOFOLLOW 0 #endif id->fd = open(zFilename, O_RDWR|O_CREAT|O_EXCL|O_NOFOLLOW, 0600); if( id->fd<0 ){ return SQLITE_CANTOPEN; } sqliteOsEnterMutex(); id->pLock = findLockInfo(id->fd); sqliteOsLeaveMutex(); if( id->pLock==0 ){ close(id->fd); unlink(zFilename); return SQLITE_NOMEM; } id->locked = 0; return SQLITE_OK; #endif #if OS_WIN HANDLE h = CreateFile(zFilename, GENERIC_READ | GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS, NULL ); if( h==INVALID_HANDLE_VALUE ){ return SQLITE_CANTOPEN; } id->h = h; id->locked = 0; return SQLITE_OK; #endif } /* ** Attempt to open a new file for read-only access. ** ** On success, write the file handle into *id and return SQLITE_OK. ** ** On failure, return SQLITE_CANTOPEN. */ int sqliteOsOpenReadOnly(const char *zFilename, OsFile *id){ #if OS_UNIX id->fd = open(zFilename, O_RDONLY); if( id->fd<0 ){ return SQLITE_CANTOPEN; } sqliteOsEnterMutex(); id->pLock = findLockInfo(id->fd); sqliteOsLeaveMutex(); if( id->pLock==0 ){ close(id->fd); return SQLITE_NOMEM; } id->locked = 0; return SQLITE_OK; #endif #if OS_WIN HANDLE h = CreateFile(zFilename, GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS, NULL ); if( h==INVALID_HANDLE_VALUE ){ return SQLITE_CANTOPEN; } id->h = h; id->locked = 0; return SQLITE_OK; #endif } /* ** Create a temporary file name in zBuf. zBuf must be big enough to ** hold at least SQLITE_TEMPNAME_SIZE characters. |
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443 444 445 446 447 448 449 | #endif return SQLITE_OK; } /* ** Close a file */ | | | | | | | | | | | | | | | | | | | | | | | | > | > > > | > > > > > > > > > > > > > > > > > > > > > > > > > > > < < < | | | | < | < < | < > | < < > | | > > | > > > > > > | | > > | | > > > | > > > | > > > | | | > | < | | < | < | < < < | < | > > > > | > > > > > | > > > > > > | 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 | #endif return SQLITE_OK; } /* ** Close a file */ int sqliteOsClose(OsFile *id){ #if OS_UNIX close(id->fd); sqliteOsEnterMutex(); releaseLockInfo(id->pLock); sqliteOsLeaveMutex(); return SQLITE_OK; #endif #if OS_WIN CloseHandle(id->h); return SQLITE_OK; #endif } /* ** Read data from a file into a buffer. Return SQLITE_OK if all ** bytes were read successfully and SQLITE_IOERR if anything goes ** wrong. */ int sqliteOsRead(OsFile *id, void *pBuf, int amt){ #if OS_UNIX int got; SimulateIOError(SQLITE_IOERR); got = read(id->fd, pBuf, amt); if( got<0 ) got = 0; return got==amt ? SQLITE_OK : SQLITE_IOERR; #endif #if OS_WIN DWORD got; SimulateIOError(SQLITE_IOERR); if( !ReadFile(id->h, pBuf, amt, &got, 0) ){ got = 0; } return got==amt ? SQLITE_OK : SQLITE_IOERR; #endif } /* ** Write data from a buffer into a file. Return SQLITE_OK on success ** or some other error code on failure. */ int sqliteOsWrite(OsFile *id, const void *pBuf, int amt){ #if OS_UNIX int wrote; SimulateIOError(SQLITE_IOERR); wrote = write(id->fd, pBuf, amt); if( wrote<amt ) return SQLITE_FULL; return SQLITE_OK; #endif #if OS_WIN DWORD wrote; SimulateIOError(SQLITE_IOERR); if( !WriteFile(id->h, pBuf, amt, &wrote, 0) || wrote<amt ){ return SQLITE_FULL; } return SQLITE_OK; #endif } /* ** Move the read/write pointer in a file. */ int sqliteOsSeek(OsFile *id, int offset){ #if OS_UNIX lseek(id->fd, offset, SEEK_SET); return SQLITE_OK; #endif #if OS_WIN SetFilePointer(id->h, offset, 0, FILE_BEGIN); return SQLITE_OK; #endif } /* ** Make sure all writes to a particular file are committed to disk. */ int sqliteOsSync(OsFile *id){ SimulateIOError(SQLITE_IOERR); #if OS_UNIX return fsync(id->fd)==0 ? SQLITE_OK : SQLITE_IOERR; #endif #if OS_WIN return FlushFileBuffers(id->h) ? SQLITE_OK : SQLITE_IOERR; #endif } /* ** Truncate an open file to a specified size */ int sqliteOsTruncate(OsFile *id, int nByte){ SimulateIOError(SQLITE_IOERR); #if OS_UNIX return ftruncate(id->fd, nByte)==0 ? SQLITE_OK : SQLITE_IOERR; #endif #if OS_WIN SetFilePointer(id->h, nByte, 0, FILE_BEGIN); SetEndOfFile(id->h); return SQLITE_OK; #endif } /* ** Determine the current size of a file in bytes */ int sqliteOsFileSize(OsFile *id, int *pSize){ #if OS_UNIX struct stat buf; SimulateIOError(SQLITE_IOERR); if( fstat(id->fd, &buf)!=0 ){ return SQLITE_IOERR; } *pSize = buf.st_size; return SQLITE_OK; #endif #if OS_WIN SimulateIOError(SQLITE_IOERR); *pSize = GetFileSize(id->h, 0); return SQLITE_OK; #endif } /* ** Change the status of the lock on the file "id" to be a readlock. ** If the file was write locked, then this reduces the lock to a read. ** If the file was read locked, then this acquires a new read lock. ** ** Return SQLITE_OK on success and SQLITE_BUSY on failure. */ int sqliteOsReadLock(OsFile *id){ #if OS_UNIX int rc; sqliteOsEnterMutex(); if( id->pLock->cnt>0 ){ if( !id->locked ){ id->pLock->cnt++; id->locked = 1; } rc = SQLITE_OK; }else if( id->locked || id->pLock->cnt==0 ){ struct flock lock; lock.l_type = F_RDLCK; lock.l_whence = SEEK_SET; lock.l_start = lock.l_len = 0L; if( fcntl(id->fd, F_SETLK, &lock)!=0 ){ rc = SQLITE_BUSY; }else{ rc = SQLITE_OK; id->pLock->cnt = 1; id->locked = 1; } }else{ rc = SQLITE_BUSY; } sqliteOsLeaveMutex(); return rc; #endif #if OS_WIN int rc; if( id->locked ){ rc = SQLITE_OK; }else if( LockFile(id->h, 0, 0, 1024, 0) ){ rc = SQLITE_OK; id->locked = 1; }else{ rc = SQLITE_BUSY; } return rc; #endif } /* ** Change the lock status to be an exclusive or write lock. Return ** SQLITE_OK on success and SQLITE_BUSY on a failure. */ int sqliteOsWriteLock(OsFile *id){ #if OS_UNIX int rc; sqliteOsEnterMutex(); if( id->pLock->cnt==0 || (id->pLock->cnt==1 && id->locked==1) ){ struct flock lock; lock.l_type = F_WRLCK; lock.l_whence = SEEK_SET; lock.l_start = lock.l_len = 0L; if( fcntl(id->fd, F_SETLK, &lock)!=0 ){ rc = SQLITE_BUSY; }else{ rc = SQLITE_OK; id->pLock->cnt = -1; id->locked = 1; } }else{ rc = SQLITE_BUSY; } sqliteOsLeaveMutex(); return rc; #endif #if OS_WIN int rc; if( id->locked ){ rc = SQLITE_OK; }else if( LockFile(id->h, 0, 0, 1024, 0) ){ rc = SQLITE_OK; id->locked = 1; }else{ rc = SQLITE_BUSY; } return rc; #endif } /* ** Unlock the given file descriptor. If the file descriptor was ** not previously locked, then this routine is a no-op. */ int sqliteOsUnlock(OsFile *id){ #if OS_UNIX int rc; if( !id->locked ) return SQLITE_OK; sqliteOsEnterMutex(); assert( id->pLock->cnt!=0 ); if( id->pLock->cnt>1 ){ id->pLock->cnt--; rc = SQLITE_OK; }else{ struct flock lock; lock.l_type = F_UNLCK; lock.l_whence = SEEK_SET; lock.l_start = lock.l_len = 0L; if( fcntl(id->fd, F_SETLK, &lock)!=0 ){ rc = SQLITE_BUSY; }else{ rc = SQLITE_OK; id->pLock->cnt = 0; } } sqliteOsLeaveMutex(); id->locked = 0; return rc; #endif #if OS_WIN int rc; if( !id->locked ){ rc = SQLITE_OK; }else if( UnlockFile(id->h, 0, 0, 1024, 0) ){ rc = SQLITE_OK; id->locked = 0; }else{ rc = SQLITE_BUSY; } return rc; #endif } /* ** Get information to seed the random number generator. */ int sqliteOsRandomSeed(char *zBuf){ |
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Changes to src/os.h.
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21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 | ** A handle for an open file is stored in an OsFile object. */ #if OS_UNIX typedef struct OsFile OsFile; struct OsFile { struct lockInfo *pLock; /* Information about locks on this inode */ int fd; /* The file descriptor */ }; # define SQLITE_TEMPNAME_SIZE 200 # if defined(HAVE_USLEEP) && HAVE_USLEEP # define SQLITE_MIN_SLEEP_MS 1 # else # define SQLITE_MIN_SLEEP_MS 1000 # endif #endif #if OS_WIN #include <windows.h> #include <winbase.h> | > > > | > > | | | | | | | | > | | 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 | ** A handle for an open file is stored in an OsFile object. */ #if OS_UNIX typedef struct OsFile OsFile; struct OsFile { struct lockInfo *pLock; /* Information about locks on this inode */ int fd; /* The file descriptor */ int locked; /* True if this user holds the lock */ }; # define SQLITE_TEMPNAME_SIZE 200 # if defined(HAVE_USLEEP) && HAVE_USLEEP # define SQLITE_MIN_SLEEP_MS 1 # else # define SQLITE_MIN_SLEEP_MS 1000 # endif #endif #if OS_WIN #include <windows.h> #include <winbase.h> typedef struct OsFile OsFile; struct OsFile { HANDLE h; int locked; }; # define SQLITE_TEMPNAME_SIZE (MAX_PATH+50) # define SQLITE_MIN_SLEEP_MS 1 #endif int sqliteOsDelete(const char*); int sqliteOsFileExists(const char*); int sqliteOsOpenReadWrite(const char*, OsFile*, int*); int sqliteOsOpenExclusive(const char*, OsFile*); int sqliteOsOpenReadOnly(const char*, OsFile*); int sqliteOsTempFileName(char*); int sqliteOsClose(OsFile*); int sqliteOsRead(OsFile*, void*, int amt); int sqliteOsWrite(OsFile*, const void*, int amt); int sqliteOsSeek(OsFile*, int offset); int sqliteOsSync(OsFile*); int sqliteOsTruncate(OsFile*, int size); int sqliteOsFileSize(OsFile*, int *pSize); int sqliteOsReadLock(OsFile*); int sqliteOsWriteLock(OsFile*); int sqliteOsUnlock(OsFile*); int sqliteOsRandomSeed(char*); int sqliteOsSleep(int ms); void sqliteOsEnterMutex(void); void sqliteOsLeaveMutex(void); |
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Changes to src/pager.c.
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14 15 16 17 18 19 20 | ** The pager is used to access a database disk file. It implements ** atomic commit and rollback through the use of a journal file that ** is separate from the database file. The pager also implements file ** locking to prevent two processes from writing the same database ** file simultaneously, or one process from reading the database while ** another is writing. ** | | | 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 | ** The pager is used to access a database disk file. It implements ** atomic commit and rollback through the use of a journal file that ** is separate from the database file. The pager also implements file ** locking to prevent two processes from writing the same database ** file simultaneously, or one process from reading the database while ** another is writing. ** ** @(#) $Id: pager.c,v 1.33 2001/12/14 15:09:57 drh Exp $ */ #include "sqliteInt.h" #include "pager.h" #include "os.h" #include <assert.h> #include <string.h> |
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214 215 216 217 218 219 220 | pPager->pLast = 0; pPager->pAll = 0; memset(pPager->aHash, 0, sizeof(pPager->aHash)); pPager->nPage = 0; if( pPager->state==SQLITE_WRITELOCK ){ sqlitepager_rollback(pPager); } | | | 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 | pPager->pLast = 0; pPager->pAll = 0; memset(pPager->aHash, 0, sizeof(pPager->aHash)); pPager->nPage = 0; if( pPager->state==SQLITE_WRITELOCK ){ sqlitepager_rollback(pPager); } sqliteOsUnlock(&pPager->fd); pPager->state = SQLITE_UNLOCK; pPager->dbSize = -1; pPager->nRef = 0; assert( pPager->journalOpen==0 ); } /* |
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242 243 244 245 246 247 248 | ** is set in pPager->errMask, and this routine returns SQLITE_PROTOCOL. ** SQLITE_OK is returned on success. */ static int pager_unwritelock(Pager *pPager){ int rc; PgHdr *pPg; if( pPager->state!=SQLITE_WRITELOCK ) return SQLITE_OK; | < < | > > < < < < < < | < | 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 | ** is set in pPager->errMask, and this routine returns SQLITE_PROTOCOL. ** SQLITE_OK is returned on success. */ static int pager_unwritelock(Pager *pPager){ int rc; PgHdr *pPg; if( pPager->state!=SQLITE_WRITELOCK ) return SQLITE_OK; sqliteOsClose(&pPager->jfd); pPager->journalOpen = 0; sqliteOsDelete(pPager->zJournal); rc = sqliteOsReadLock(&pPager->fd); assert( rc==SQLITE_OK ); sqliteFree( pPager->aInJournal ); pPager->aInJournal = 0; for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){ pPg->inJournal = 0; pPg->dirty = 0; } pPager->state = SQLITE_READLOCK; return rc; } /* ** Playback the journal and thus restore the database file to ** the state it was in before we started making changes. ** |
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300 301 302 303 304 305 306 | unsigned char aMagic[sizeof(aJournalMagic)]; int rc; /* Figure out how many records are in the journal. Abort early if ** the journal is empty. */ assert( pPager->journalOpen ); | | | | | | | | | | | 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 | unsigned char aMagic[sizeof(aJournalMagic)]; int rc; /* Figure out how many records are in the journal. Abort early if ** the journal is empty. */ assert( pPager->journalOpen ); sqliteOsSeek(&pPager->jfd, 0); rc = sqliteOsFileSize(&pPager->jfd, &nRec); if( rc!=SQLITE_OK ){ goto end_playback; } nRec = (nRec - (sizeof(aMagic)+sizeof(Pgno))) / sizeof(PageRecord); if( nRec<=0 ){ goto end_playback; } /* Read the beginning of the journal and truncate the ** database file back to its original size. */ rc = sqliteOsRead(&pPager->jfd, aMagic, sizeof(aMagic)); if( rc!=SQLITE_OK || memcmp(aMagic,aJournalMagic,sizeof(aMagic))!=0 ){ rc = SQLITE_PROTOCOL; goto end_playback; } rc = sqliteOsRead(&pPager->jfd, &mxPg, sizeof(mxPg)); if( rc!=SQLITE_OK ){ goto end_playback; } rc = sqliteOsTruncate(&pPager->fd, mxPg*SQLITE_PAGE_SIZE); if( rc!=SQLITE_OK ){ goto end_playback; } pPager->dbSize = mxPg; /* Process segments beginning with the last and working backwards ** to the first. */ for(i=nRec-1; i>=0; i--){ /* Seek to the beginning of the segment */ int ofst; ofst = i*sizeof(PageRecord) + sizeof(aMagic) + sizeof(Pgno); rc = sqliteOsSeek(&pPager->jfd, ofst); if( rc!=SQLITE_OK ) break; rc = sqliteOsRead(&pPager->jfd, &pgRec, sizeof(pgRec)); if( rc!=SQLITE_OK ) break; /* Sanity checking on the page */ if( pgRec.pgno>mxPg || pgRec.pgno==0 ){ rc = SQLITE_CORRUPT; break; } /* Playback the page. Update the in-memory copy of the page ** at the same time, if there is one. */ pPg = pager_lookup(pPager, pgRec.pgno); if( pPg ){ memcpy(PGHDR_TO_DATA(pPg), pgRec.aData, SQLITE_PAGE_SIZE); memset(PGHDR_TO_EXTRA(pPg), 0, pPager->nExtra); } rc = sqliteOsSeek(&pPager->fd, (pgRec.pgno-1)*SQLITE_PAGE_SIZE); if( rc!=SQLITE_OK ) break; rc = sqliteOsWrite(&pPager->fd, pgRec.aData, SQLITE_PAGE_SIZE); if( rc!=SQLITE_OK ) break; } end_playback: if( rc!=SQLITE_OK ){ pager_unwritelock(pPager); pPager->errMask |= PAGER_ERR_CORRUPT; |
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428 429 430 431 432 433 434 | } if( rc!=SQLITE_OK ){ return SQLITE_CANTOPEN; } nameLen = strlen(zFilename); pPager = sqliteMalloc( sizeof(*pPager) + nameLen*2 + 30 ); if( pPager==0 ){ | | | 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 | } if( rc!=SQLITE_OK ){ return SQLITE_CANTOPEN; } nameLen = strlen(zFilename); pPager = sqliteMalloc( sizeof(*pPager) + nameLen*2 + 30 ); if( pPager==0 ){ sqliteOsClose(&fd); return SQLITE_NOMEM; } pPager->zFilename = (char*)&pPager[1]; pPager->zJournal = &pPager->zFilename[nameLen+1]; strcpy(pPager->zFilename, zFilename); strcpy(pPager->zJournal, zFilename); strcpy(&pPager->zJournal[nameLen], "-journal"); |
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477 478 479 480 481 482 483 | */ int sqlitepager_pagecount(Pager *pPager){ int n; assert( pPager!=0 ); if( pPager->dbSize>=0 ){ return pPager->dbSize; } | | | 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 | */ int sqlitepager_pagecount(Pager *pPager){ int n; assert( pPager!=0 ); if( pPager->dbSize>=0 ){ return pPager->dbSize; } if( sqliteOsFileSize(&pPager->fd, &n)!=SQLITE_OK ){ pPager->errMask |= PAGER_ERR_DISK; return 0; } n /= SQLITE_PAGE_SIZE; if( pPager->state!=SQLITE_UNLOCK ){ pPager->dbSize = n; } |
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502 503 504 505 506 507 508 | ** result in a coredump. */ int sqlitepager_close(Pager *pPager){ PgHdr *pPg, *pNext; switch( pPager->state ){ case SQLITE_WRITELOCK: { sqlitepager_rollback(pPager); | | | | | 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 | ** result in a coredump. */ int sqlitepager_close(Pager *pPager){ PgHdr *pPg, *pNext; switch( pPager->state ){ case SQLITE_WRITELOCK: { sqlitepager_rollback(pPager); sqliteOsUnlock(&pPager->fd); assert( pPager->journalOpen==0 ); break; } case SQLITE_READLOCK: { sqliteOsUnlock(&pPager->fd); break; } default: { /* Do nothing */ break; } } for(pPg=pPager->pAll; pPg; pPg=pNext){ pNext = pPg->pNextAll; sqliteFree(pPg); } sqliteOsClose(&pPager->fd); assert( pPager->journalOpen==0 ); if( pPager->tempFile ){ sqliteOsDelete(pPager->zFilename); } sqliteFree(pPager); return SQLITE_OK; } |
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586 587 588 589 590 591 592 | ** of having to do another fsync() later on. Writing dirty free pages ** in this way make database operations go up to 10 times faster. */ static int syncAllPages(Pager *pPager){ PgHdr *pPg; int rc = SQLITE_OK; if( pPager->needSync ){ | | | | | 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 | ** of having to do another fsync() later on. Writing dirty free pages ** in this way make database operations go up to 10 times faster. */ static int syncAllPages(Pager *pPager){ PgHdr *pPg; int rc = SQLITE_OK; if( pPager->needSync ){ rc = sqliteOsSync(&pPager->jfd); if( rc!=0 ) return rc; pPager->needSync = 0; } for(pPg=pPager->pFirst; pPg; pPg=pPg->pNextFree){ if( pPg->dirty ){ sqliteOsSeek(&pPager->fd, (pPg->pgno-1)*SQLITE_PAGE_SIZE); rc = sqliteOsWrite(&pPager->fd, PGHDR_TO_DATA(pPg), SQLITE_PAGE_SIZE); if( rc!=SQLITE_OK ) break; pPg->dirty = 0; } } return rc; } |
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640 641 642 643 644 645 646 | return pager_errcode(pPager); } /* If this is the first page accessed, then get a read lock ** on the database file. */ if( pPager->nRef==0 ){ | | > > > > > > > > > > > | | < | < < < < < < < < < < | < < < < | 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 | return pager_errcode(pPager); } /* If this is the first page accessed, then get a read lock ** on the database file. */ if( pPager->nRef==0 ){ if( sqliteOsReadLock(&pPager->fd)!=SQLITE_OK ){ *ppPage = 0; return SQLITE_BUSY; } pPager->state = SQLITE_READLOCK; /* If a journal file exists, try to play it back. */ if( sqliteOsFileExists(pPager->zJournal) ){ int rc, dummy; /* Get a write lock on the database */ rc = sqliteOsWriteLock(&pPager->fd); if( rc!=SQLITE_OK ){ rc = sqliteOsReadLock(&pPager->fd); assert( rc==SQLITE_OK ); *ppPage = 0; return SQLITE_BUSY; } pPager->state = SQLITE_WRITELOCK; /* Open the journal for exclusive access. Return SQLITE_BUSY if ** we cannot get exclusive access to the journal file. ** ** Even though we will only be reading from the journal, not writing, ** we have to open the journal for writing in order to obtain an ** exclusive access lock. */ rc = sqliteOsOpenReadWrite(pPager->zJournal, &pPager->jfd, &dummy); if( rc!=SQLITE_OK ){ rc = sqliteOsUnlock(&pPager->fd); assert( rc==SQLITE_OK ); *ppPage = 0; return SQLITE_BUSY; } pPager->journalOpen = 1; /* Playback and delete the journal. Drop the database write ** lock and reacquire the read lock. */ rc = pager_playback(pPager); if( rc!=SQLITE_OK ){ return rc; |
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800 801 802 803 804 805 806 | pPg->pNextHash->pPrevHash = pPg; } if( pPager->dbSize<0 ) sqlitepager_pagecount(pPager); if( pPager->dbSize<pgno ){ memset(PGHDR_TO_DATA(pPg), 0, SQLITE_PAGE_SIZE); }else{ int rc; | | | | 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 | pPg->pNextHash->pPrevHash = pPg; } if( pPager->dbSize<0 ) sqlitepager_pagecount(pPager); if( pPager->dbSize<pgno ){ memset(PGHDR_TO_DATA(pPg), 0, SQLITE_PAGE_SIZE); }else{ int rc; sqliteOsSeek(&pPager->fd, (pgno-1)*SQLITE_PAGE_SIZE); rc = sqliteOsRead(&pPager->fd, PGHDR_TO_DATA(pPg), SQLITE_PAGE_SIZE); if( rc!=SQLITE_OK ){ return rc; } } if( pPager->nExtra>0 ){ memset(PGHDR_TO_EXTRA(pPg), 0, pPager->nExtra); } |
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930 931 932 933 934 935 936 937 938 | return SQLITE_PERM; } pPg->dirty = 1; if( pPg->inJournal ){ return SQLITE_OK; } assert( pPager->state!=SQLITE_UNLOCK ); if( pPager->state==SQLITE_READLOCK ){ assert( pPager->aInJournal==0 ); pPager->aInJournal = sqliteMalloc( pPager->dbSize/8 + 1 ); if( pPager->aInJournal==0 ){ | > > > > | > > < < < < < < < < < < < < < < < < < < < < < < < < | | | | | 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 | return SQLITE_PERM; } pPg->dirty = 1; if( pPg->inJournal ){ return SQLITE_OK; } assert( pPager->state!=SQLITE_UNLOCK ); if( pPager->state==SQLITE_READLOCK ){ assert( pPager->aInJournal==0 ); rc = sqliteOsWriteLock(&pPager->fd); if( rc!=SQLITE_OK ){ return rc; } pPager->aInJournal = sqliteMalloc( pPager->dbSize/8 + 1 ); if( pPager->aInJournal==0 ){ sqliteOsReadLock(&pPager->fd); return SQLITE_NOMEM; } rc = sqliteOsOpenExclusive(pPager->zJournal, &pPager->jfd); if( rc!=SQLITE_OK ){ sqliteFree(pPager->aInJournal); pPager->aInJournal = 0; sqliteOsReadLock(&pPager->fd); return SQLITE_CANTOPEN; } pPager->journalOpen = 1; pPager->needSync = 0; pPager->state = SQLITE_WRITELOCK; sqlitepager_pagecount(pPager); pPager->origDbSize = pPager->dbSize; rc = sqliteOsWrite(&pPager->jfd, aJournalMagic, sizeof(aJournalMagic)); if( rc==SQLITE_OK ){ rc = sqliteOsWrite(&pPager->jfd, &pPager->dbSize, sizeof(Pgno)); } if( rc!=SQLITE_OK ){ rc = pager_unwritelock(pPager); if( rc==SQLITE_OK ) rc = SQLITE_FULL; return rc; } } assert( pPager->state==SQLITE_WRITELOCK ); assert( pPager->journalOpen ); if( pPg->pgno <= pPager->origDbSize ){ rc = sqliteOsWrite(&pPager->jfd, &pPg->pgno, sizeof(Pgno)); if( rc==SQLITE_OK ){ rc = sqliteOsWrite(&pPager->jfd, pData, SQLITE_PAGE_SIZE); } if( rc!=SQLITE_OK ){ sqlitepager_rollback(pPager); pPager->errMask |= PAGER_ERR_FULL; return rc; } assert( pPager->aInJournal!=0 ); |
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1036 1037 1038 1039 1040 1041 1042 | rc = pager_errcode(pPager); return rc; } if( pPager->state!=SQLITE_WRITELOCK ){ return SQLITE_ERROR; } assert( pPager->journalOpen ); | | | | | | 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 | rc = pager_errcode(pPager); return rc; } if( pPager->state!=SQLITE_WRITELOCK ){ return SQLITE_ERROR; } assert( pPager->journalOpen ); if( pPager->needSync && sqliteOsSync(&pPager->jfd)!=SQLITE_OK ){ goto commit_abort; } for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){ if( pPg->dirty==0 ) continue; rc = sqliteOsSeek(&pPager->fd, (pPg->pgno-1)*SQLITE_PAGE_SIZE); if( rc!=SQLITE_OK ) goto commit_abort; rc = sqliteOsWrite(&pPager->fd, PGHDR_TO_DATA(pPg), SQLITE_PAGE_SIZE); if( rc!=SQLITE_OK ) goto commit_abort; } if( sqliteOsSync(&pPager->fd)!=SQLITE_OK ) goto commit_abort; rc = pager_unwritelock(pPager); pPager->dbSize = -1; return rc; /* Jump here if anything goes wrong during the commit process. */ commit_abort: |
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Changes to www/changes.tcl.
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12 13 14 15 16 17 18 19 20 21 22 23 24 25 | } proc chng {date desc} { puts "<DT><B>$date</B></DT>" puts "<DD><P><UL>$desc</UL></P></DD>" } chng {2001 Dec 6 (2.1.5)} { <li>Fix for another problem (unrelated to the one fixed in 2.1.4) that sometimes causes <b>sqlite_exec()</b> to return SQLITE_PROTOCOL unnecessarily. This time the bug was in the POSIX locking code and should not effect windows users.</li> } | > > > > > > > | 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 | } proc chng {date desc} { puts "<DT><B>$date</B></DT>" puts "<DD><P><UL>$desc</UL></P></DD>" } chng {2001 Dec 14 (2.1.6)} { <li>Fix the locking mechanism yet again to prevent <b>sqlite_exec()</b> from returning SQLITE_PROTOCOL unnecessarily. This time the bug was a race condition in the locking code. This change effects both POSIX and Windows users.</li> } chng {2001 Dec 6 (2.1.5)} { <li>Fix for another problem (unrelated to the one fixed in 2.1.4) that sometimes causes <b>sqlite_exec()</b> to return SQLITE_PROTOCOL unnecessarily. This time the bug was in the POSIX locking code and should not effect windows users.</li> } |
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