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Changes In Branch faster-pcache1-fetch Excluding Merge-Ins
This is equivalent to a diff from 2e8ad2ea to dcf4fb8d
2015-06-13
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11:19 | Omit mutex calls in pcache1 when the mutex is NULL, for a significant performance improvement. (check-in: caf8f574 user: drh tags: trunk) | |
11:10 | Avoid unnecessary mutex usage in pcache1, for a significant speedup. (Closed-Leaf check-in: dcf4fb8d user: drh tags: faster-pcache1-fetch) | |
2015-06-12
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13:49 | Add a fast-path implementation of pcache1Fetch() for the common case of separate caches that do not use a mutex. (check-in: 760700ed user: drh tags: faster-pcache1-fetch) | |
13:04 | Minor performance optimization in pcache1.c. (check-in: 2e8ad2ea user: drh tags: trunk) | |
12:54 | Add the OP_ColumnsUsed opcode (when compiled with SQLITE_ENABLE_COLUMN_USED_MASK) as a hint to the b-tree layer as to which columns of a btree cursor will be used. (check-in: 711a176c user: drh tags: trunk) | |
Changes to src/pcache1.c.
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144 145 146 147 148 149 150 | ** compiling for systems that do not support real WSD. */ #define pcache1 (GLOBAL(struct PCacheGlobal, pcache1_g)) /* ** Macros to enter and leave the PCache LRU mutex. */ | > > > > > | | > > | 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 | ** compiling for systems that do not support real WSD. */ #define pcache1 (GLOBAL(struct PCacheGlobal, pcache1_g)) /* ** Macros to enter and leave the PCache LRU mutex. */ #if !defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) || SQLITE_THREADSAFE==0 # define pcache1EnterMutex(X) assert((X)->mutex==0) # define pcache1LeaveMutex(X) assert((X)->mutex==0) # define PCACHE1_MIGHT_USE_GROUP_MUTEX 0 #else # define pcache1EnterMutex(X) sqlite3_mutex_enter((X)->mutex) # define pcache1LeaveMutex(X) sqlite3_mutex_leave((X)->mutex) # define PCACHE1_MIGHT_USE_GROUP_MUTEX 1 #endif /******************************************************************************/ /******** Page Allocation/SQLITE_CONFIG_PCACHE Related Functions **************/ /* ** This function is called during initialization if a static buffer is ** supplied to use for the page-cache by passing the SQLITE_CONFIG_PAGECACHE |
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421 422 423 424 425 426 427 | /* ** This function is used internally to remove the page pPage from the ** PGroup LRU list, if is part of it. If pPage is not part of the PGroup ** LRU list, then this function is a no-op. ** ** The PGroup mutex must be held when this function is called. */ | | | 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 | /* ** This function is used internally to remove the page pPage from the ** PGroup LRU list, if is part of it. If pPage is not part of the PGroup ** LRU list, then this function is a no-op. ** ** The PGroup mutex must be held when this function is called. */ static PgHdr1 *pcache1PinPage(PgHdr1 *pPage){ PCache1 *pCache; assert( pPage!=0 ); assert( pPage->isPinned==0 ); pCache = pPage->pCache; assert( pPage->pLruNext || pPage==pCache->pGroup->pLruTail ); assert( pPage->pLruPrev || pPage==pCache->pGroup->pLruHead ); |
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444 445 446 447 448 449 450 451 452 453 454 455 456 457 | }else{ pCache->pGroup->pLruTail = pPage->pLruPrev; } pPage->pLruNext = 0; pPage->pLruPrev = 0; pPage->isPinned = 1; pCache->nRecyclable--; } /* ** Remove the page supplied as an argument from the hash table ** (PCache1.apHash structure) that it is currently stored in. ** | > | 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 | }else{ pCache->pGroup->pLruTail = pPage->pLruPrev; } pPage->pLruNext = 0; pPage->pLruPrev = 0; pPage->isPinned = 1; pCache->nRecyclable--; return pPage; } /* ** Remove the page supplied as an argument from the hash table ** (PCache1.apHash structure) that it is currently stored in. ** |
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524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 | /* ** 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( sqlite3GlobalConfig.bCoreMutex ){ pcache1.grp.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_LRU); pcache1.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_PMEM); } pcache1.grp.mxPinned = 10; pcache1.isInit = 1; return SQLITE_OK; } /* ** Implementation of the sqlite3_pcache.xShutdown method. | > > | 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 | /* ** 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; pcache1.isInit = 1; return SQLITE_OK; } /* ** Implementation of the sqlite3_pcache.xShutdown method. |
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799 800 801 802 803 804 805 806 | ** unnecessary pages cache entry allocations ** ** then attempt to recycle a page from the LRU list. If it is the right ** size, return the recycled buffer. Otherwise, free the buffer and ** proceed to step 5. ** ** 5. Otherwise, allocate and return a new page buffer. */ | > > > > > | < < < < < < < < | > > > > | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | > | 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 | ** unnecessary pages cache entry allocations ** ** then attempt to recycle a page from the LRU list. If it is the right ** size, return the recycled buffer. Otherwise, free the buffer and ** proceed to step 5. ** ** 5. Otherwise, allocate and return a new page buffer. ** ** There are two versions of this routine. pcache1FetchWithMutex() is ** the general case. pcache1FetchNoMutex() is a faster implementation for ** the common case where pGroup->mutex is NULL. The pcache1Fetch() wrapper ** invokes the appropriate routine. */ static PgHdr1 *pcache1FetchNoMutex( sqlite3_pcache *p, unsigned int iKey, int createFlag ){ PCache1 *pCache = (PCache1 *)p; PgHdr1 *pPage = 0; /* Step 1: Search the hash table for an existing entry. */ pPage = pCache->apHash[iKey % pCache->nHash]; while( pPage && pPage->iKey!=iKey ){ pPage = pPage->pNext; } /* Step 2: Abort if no existing page is found and createFlag is 0 */ if( pPage ){ if( !pPage->isPinned ){ return pcache1PinPage(pPage); }else{ return pPage; } }else if( createFlag ){ /* Steps 3, 4, and 5 implemented by this subroutine */ return pcache1FetchStage2(pCache, iKey, createFlag); }else{ return 0; } } #if PCACHE1_MIGHT_USE_GROUP_MUTEX static PgHdr1 *pcache1FetchWithMutex( sqlite3_pcache *p, unsigned int iKey, int createFlag ){ PCache1 *pCache = (PCache1 *)p; PgHdr1 *pPage; pcache1EnterMutex(pCache->pGroup); pPage = pcache1FetchNoMutex(p, iKey, createFlag); assert( pPage==0 || pCache->iMaxKey>=iKey ); pcache1LeaveMutex(pCache->pGroup); return pPage; } #endif static sqlite3_pcache_page *pcache1Fetch( sqlite3_pcache *p, unsigned int iKey, int createFlag ){ #if PCACHE1_MIGHT_USE_GROUP_MUTEX || defined(SQLITE_DEBUG) PCache1 *pCache = (PCache1 *)p; #endif assert( offsetof(PgHdr1,page)==0 ); assert( pCache->bPurgeable || createFlag!=1 ); assert( pCache->bPurgeable || pCache->nMin==0 ); assert( pCache->bPurgeable==0 || pCache->nMin==10 ); assert( pCache->nMin==0 || pCache->bPurgeable ); assert( pCache->nHash>0 ); #if PCACHE1_MIGHT_USE_GROUP_MUTEX if( pCache->pGroup->mutex ){ return (sqlite3_pcache_page*)pcache1FetchWithMutex(p, iKey, createFlag); }else #endif { return (sqlite3_pcache_page*)pcache1FetchNoMutex(p, iKey, createFlag); } } /* ** Implementation of the sqlite3_pcache.xUnpin method. ** ** Mark a page as unpinned (eligible for asynchronous recycling). |
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