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Overview
Comment: | A unified cache is now only used for SQLITE_ENABLE_MEMORY_MANAGEMENT, or if SQLITE_CONFIG_PAGECACHE defines a shared start-time page cache buffer and the application is single-threaded. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | pcache-bulk-local |
Files: | files | file ages | folders |
SHA1: |
d5ff1d69054d51a55eff6e1979971822 |
User & Date: | drh 2015-07-06 20:57:22.615 |
Context
2015-07-07
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14:06 | Simplify the page recycling condition in pcache1. Fix test cases to work with the latest changes. (check-in: 5b60df5503 user: drh tags: pcache-bulk-local) | |
2015-07-06
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20:57 | A unified cache is now only used for SQLITE_ENABLE_MEMORY_MANAGEMENT, or if SQLITE_CONFIG_PAGECACHE defines a shared start-time page cache buffer and the application is single-threaded. (check-in: d5ff1d6905 user: drh tags: pcache-bulk-local) | |
18:54 | Enhance separate pcache1 to allocate a block of pages from heap on startup, if possible, for a 5.2% performance improvement. (check-in: aa7341c873 user: drh tags: pcache-bulk-local) | |
Changes
Changes to src/pcache1.c.
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185 186 187 188 189 190 191 192 193 194 195 196 197 198 | /* Variables related to SQLITE_CONFIG_PAGECACHE settings. The ** szSlot, nSlot, pStart, pEnd, nReserve, and isInit values are all ** fixed at sqlite3_initialize() time and do not require mutex protection. ** The nFreeSlot and pFree values do require mutex protection. */ int isInit; /* True if initialized */ int szSlot; /* Size of each free slot */ int nSlot; /* The number of pcache slots */ int nReserve; /* Try to keep nFreeSlot above this */ void *pStart, *pEnd; /* Bounds of global page cache memory */ /* Above requires no mutex. Use mutex below for variable that follow. */ sqlite3_mutex *mutex; /* Mutex for accessing the following: */ PgFreeslot *pFree; /* Free page blocks */ | > | 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 | /* Variables related to SQLITE_CONFIG_PAGECACHE settings. The ** szSlot, nSlot, pStart, pEnd, nReserve, and isInit values are all ** fixed at sqlite3_initialize() time and do not require mutex protection. ** The nFreeSlot and pFree values do require mutex protection. */ int isInit; /* True if initialized */ int separateCache; /* Use a new PGroup for each PCache */ int szSlot; /* Size of each free slot */ int nSlot; /* The number of pcache slots */ int nReserve; /* Try to keep nFreeSlot above this */ void *pStart, *pEnd; /* Bounds of global page cache memory */ /* Above requires no mutex. Use mutex below for variable that follow. */ sqlite3_mutex *mutex; /* Mutex for accessing the following: */ PgFreeslot *pFree; /* Free page blocks */ |
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358 359 360 361 362 363 364 365 | assert( sqlite3_mutex_held(pCache->pGroup->mutex) ); if( pCache->pFree ){ p = pCache->pFree; pCache->pFree = p->pNext; p->pNext = 0; }else{ /* The group mutex must be released before pcache1Alloc() is called. This | > | > > > > > < < < < > | | | | | | | | | | | | < | 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 | assert( sqlite3_mutex_held(pCache->pGroup->mutex) ); if( pCache->pFree ){ p = pCache->pFree; pCache->pFree = p->pNext; p->pNext = 0; }else{ #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT /* The group mutex must be released before pcache1Alloc() is called. This ** is because it might call sqlite3_release_memory(), which assumes that ** this mutex is not held. */ assert( pcache1.separateCache==0 ); assert( pCache->pGroup==&pcache1.grp ); pcache1LeaveMutex(pCache->pGroup); #endif #ifdef SQLITE_PCACHE_SEPARATE_HEADER pPg = pcache1Alloc(pCache->szPage); p = sqlite3Malloc(sizeof(PgHdr1) + pCache->szExtra); if( !pPg || !p ){ pcache1Free(pPg); sqlite3_free(p); pPg = 0; } #else pPg = pcache1Alloc(pCache->szAlloc); p = (PgHdr1 *)&((u8 *)pPg)[pCache->szPage]; #endif #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT pcache1EnterMutex(pCache->pGroup); #endif if( pPg==0 ) return 0; p->page.pBuf = pPg; p->page.pExtra = &p[1]; p->isBulkLocal = 0; } if( pCache->bPurgeable ){ pCache->pGroup->nCurrentPage++; } return p; } /* ** Free a page object allocated by pcache1AllocPage(). */ static void pcache1FreePage(PgHdr1 *p){ PCache1 *pCache; assert( p!=0 ); pCache = p->pCache; assert( sqlite3_mutex_held(p->pCache->pGroup->mutex) ); if( p->isBulkLocal ){ p->pNext = pCache->pFree; pCache->pFree = p; }else{ pcache1Free(p->page.pBuf); #ifdef SQLITE_PCACHE_SEPARATE_HEADER sqlite3_free(p); #endif } if( pCache->bPurgeable ){ pCache->pGroup->nCurrentPage--; } } /* ** Malloc function used by SQLite to obtain space from the buffer configured ** using sqlite3_config(SQLITE_CONFIG_PAGECACHE) option. If no such buffer ** exists, this function falls back to sqlite3Malloc(). |
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608 609 610 611 612 613 614 615 616 617 618 619 620 621 | /* ** Implementation of the sqlite3_pcache.xInit method. */ static int pcache1Init(void *NotUsed){ UNUSED_PARAMETER(NotUsed); assert( pcache1.isInit==0 ); memset(&pcache1, 0, sizeof(pcache1)); #if SQLITE_THREADSAFE if( sqlite3GlobalConfig.bCoreMutex ){ pcache1.grp.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_LRU); pcache1.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_PMEM); } #endif pcache1.grp.mxPinned = 10; | > > > > > > > > > > > > > > > > > > > > > > > | 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 | /* ** Implementation of the sqlite3_pcache.xInit method. */ static int pcache1Init(void *NotUsed){ UNUSED_PARAMETER(NotUsed); assert( pcache1.isInit==0 ); memset(&pcache1, 0, sizeof(pcache1)); /* ** The pcache1.separateCache variable is true if each PCache has its own ** private PGroup (mode-1). pcache1.separateCache is false if the single ** PGroup in pcache1.grp is used for all page caches (mode-2). ** ** * Always use a unified cache (mode-2) if ENABLE_MEMORY_MANAGEMENT ** ** * Use a unified cache in single-threaded applications that have ** configured a start-time buffer for use as page-cache memory using ** sqlite3_config(SQLITE_CONFIG_PAGECACHE, pBuf, sz, N) with non-NULL ** pBuf argument. ** ** * Otherwise use separate caches (mode-1) */ #if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) pcache1.separateCache = 0; #else pcache1.separateCache = sqlite3GlobalConfig.pPage==0 || sqlite3GlobalConfig.bCoreMutex>0; #endif #if SQLITE_THREADSAFE if( sqlite3GlobalConfig.bCoreMutex ){ pcache1.grp.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_LRU); pcache1.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_PMEM); } #endif pcache1.grp.mxPinned = 10; |
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643 644 645 646 647 648 649 | ** Allocate a new cache. */ static sqlite3_pcache *pcache1Create(int szPage, int szExtra, int bPurgeable){ PCache1 *pCache; /* The newly created page cache */ PGroup *pGroup; /* The group the new page cache will belong to */ int sz; /* Bytes of memory required to allocate the new cache */ | < < < < < < < < < < < < < < < < < < | | > | < | < | 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 | ** Allocate a new cache. */ static sqlite3_pcache *pcache1Create(int szPage, int szExtra, int bPurgeable){ PCache1 *pCache; /* The newly created page cache */ PGroup *pGroup; /* The group the new page cache will belong to */ int sz; /* Bytes of memory required to allocate the new cache */ assert( (szPage & (szPage-1))==0 && szPage>=512 && szPage<=65536 ); assert( szExtra < 300 ); sz = sizeof(PCache1) + sizeof(PGroup)*pcache1.separateCache; pCache = (PCache1 *)sqlite3MallocZero(sz); if( pCache ){ if( pcache1.separateCache ){ pGroup = (PGroup*)&pCache[1]; pGroup->mxPinned = 10; }else{ pGroup = &pcache1.grp; } pCache->pGroup = pGroup; pCache->szPage = szPage; pCache->szExtra = szExtra; pCache->szAlloc = szPage + szExtra + ROUND8(sizeof(PgHdr1)); pCache->bPurgeable = (bPurgeable ? 1 : 0); pcache1EnterMutex(pGroup); pcache1ResizeHash(pCache); if( bPurgeable ){ pCache->nMin = 10; pGroup->nMinPage += pCache->nMin; pGroup->mxPinned = pGroup->nMaxPage + 10 - pGroup->nMinPage; } pcache1LeaveMutex(pGroup); /* Try to initialize the local bulk pagecache line allocation if using ** separate caches and if nPage!=0 */ if( pcache1.separateCache && sqlite3GlobalConfig.nPage!=0 ){ int szBulk; char *zBulk; sqlite3BeginBenignMalloc(); if( sqlite3GlobalConfig.nPage>0 ){ szBulk = pCache->szAlloc * sqlite3GlobalConfig.nPage; }else{ szBulk = -1024*sqlite3GlobalConfig.nPage; |
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