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Overview
Comment: | Faster memory allocation from lookaside by not trying to keep track of the number of outstanding allocations, and rather computing that value only when requested. |
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Timelines: | family | ancestors | descendants | both | trunk |
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SHA3-256: |
a06263f1efd2d45eac88b8d59e8fe8e4 |
User & Date: | drh 2017-08-29 20:21:12.167 |
Context
2017-08-30
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04:44 | Small performance optimization in pcache1. (check-in: ffd437da95 user: drh tags: trunk) | |
2017-08-29
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20:21 | Faster memory allocation from lookaside by not trying to keep track of the number of outstanding allocations, and rather computing that value only when requested. (check-in: a06263f1ef user: drh tags: trunk) | |
2017-08-28
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17:00 | Add the --enable-update-limit option to the ./configure script. (check-in: 64a8ae6838 user: drh tags: trunk) | |
Changes
Changes to src/build.c.
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594 595 596 597 598 599 600 | ** contains lookaside memory. (Table objects in the schema do not use ** lookaside memory, but some ephemeral Table objects do.) Or the ** db parameter can be used with db->pnBytesFreed to measure the memory ** used by the Table object. */ static void SQLITE_NOINLINE deleteTable(sqlite3 *db, Table *pTable){ Index *pIndex, *pNext; | < > > | | > > | 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 | ** contains lookaside memory. (Table objects in the schema do not use ** lookaside memory, but some ephemeral Table objects do.) Or the ** db parameter can be used with db->pnBytesFreed to measure the memory ** used by the Table object. */ static void SQLITE_NOINLINE deleteTable(sqlite3 *db, Table *pTable){ Index *pIndex, *pNext; #ifdef SQLITE_DEBUG /* Record the number of outstanding lookaside allocations in schema Tables ** prior to doing any free() operations. Since schema Tables do not use ** lookaside, this number should not change. */ int nLookaside = 0; if( db && (pTable->tabFlags & TF_Ephemeral)==0 ){ nLookaside = sqlite3LookasideUsed(db, 0); } #endif /* Delete all indices associated with this table. */ for(pIndex = pTable->pIndex; pIndex; pIndex=pNext){ pNext = pIndex->pNext; assert( pIndex->pSchema==pTable->pSchema || (IsVirtual(pTable) && pIndex->idxType!=SQLITE_IDXTYPE_APPDEF) ); if( (db==0 || db->pnBytesFreed==0) && !IsVirtual(pTable) ){ |
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634 635 636 637 638 639 640 | sqlite3ExprListDelete(db, pTable->pCheck); #ifndef SQLITE_OMIT_VIRTUALTABLE sqlite3VtabClear(db, pTable); #endif sqlite3DbFree(db, pTable); /* Verify that no lookaside memory was used by schema tables */ | | | 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 | sqlite3ExprListDelete(db, pTable->pCheck); #ifndef SQLITE_OMIT_VIRTUALTABLE sqlite3VtabClear(db, pTable); #endif sqlite3DbFree(db, pTable); /* Verify that no lookaside memory was used by schema tables */ assert( nLookaside==0 || nLookaside==sqlite3LookasideUsed(db,0) ); } void sqlite3DeleteTable(sqlite3 *db, Table *pTable){ /* Do not delete the table until the reference count reaches zero. */ if( !pTable ) return; if( ((!db || db->pnBytesFreed==0) && (--pTable->nTabRef)>0) ) return; deleteTable(db, pTable); } |
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Changes to src/main.c.
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654 655 656 657 658 659 660 | ** space for the lookaside memory is obtained from sqlite3_malloc(). ** If pStart is not NULL then it is sz*cnt bytes of memory to use for ** the lookaside memory. */ static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){ #ifndef SQLITE_OMIT_LOOKASIDE void *pStart; | | > | 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 | ** space for the lookaside memory is obtained from sqlite3_malloc(). ** If pStart is not NULL then it is sz*cnt bytes of memory to use for ** the lookaside memory. */ static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){ #ifndef SQLITE_OMIT_LOOKASIDE void *pStart; if( sqlite3LookasideUsed(db,0)>0 ){ return SQLITE_BUSY; } /* Free any existing lookaside buffer for this handle before ** allocating a new one so we don't have to have space for ** both at the same time. */ if( db->lookaside.bMalloced ){ |
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682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 | pStart = sqlite3Malloc( sz*cnt ); /* IMP: R-61949-35727 */ sqlite3EndBenignMalloc(); if( pStart ) cnt = sqlite3MallocSize(pStart)/sz; }else{ pStart = pBuf; } db->lookaside.pStart = pStart; db->lookaside.pFree = 0; db->lookaside.sz = (u16)sz; if( pStart ){ int i; LookasideSlot *p; assert( sz > (int)sizeof(LookasideSlot*) ); p = (LookasideSlot*)pStart; for(i=cnt-1; i>=0; i--){ | > > | | > | 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 | pStart = sqlite3Malloc( sz*cnt ); /* IMP: R-61949-35727 */ sqlite3EndBenignMalloc(); if( pStart ) cnt = sqlite3MallocSize(pStart)/sz; }else{ pStart = pBuf; } db->lookaside.pStart = pStart; db->lookaside.pInit = 0; db->lookaside.pFree = 0; db->lookaside.sz = (u16)sz; if( pStart ){ int i; LookasideSlot *p; assert( sz > (int)sizeof(LookasideSlot*) ); db->lookaside.nSlot = cnt; p = (LookasideSlot*)pStart; for(i=cnt-1; i>=0; i--){ p->pNext = db->lookaside.pInit; db->lookaside.pInit = p; p = (LookasideSlot*)&((u8*)p)[sz]; } db->lookaside.pEnd = p; db->lookaside.bDisable = 0; db->lookaside.bMalloced = pBuf==0 ?1:0; }else{ db->lookaside.pStart = db; db->lookaside.pEnd = db; db->lookaside.bDisable = 1; db->lookaside.bMalloced = 0; db->lookaside.nSlot = 0; } #endif /* SQLITE_OMIT_LOOKASIDE */ return SQLITE_OK; } /* ** Return the mutex associated with a database connection. |
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1221 1222 1223 1224 1225 1226 1227 | ** the same sqliteMalloc() as the one that allocates the database ** structure? */ sqlite3DbFree(db, db->aDb[1].pSchema); sqlite3_mutex_leave(db->mutex); db->magic = SQLITE_MAGIC_CLOSED; sqlite3_mutex_free(db->mutex); | | | 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 | ** the same sqliteMalloc() as the one that allocates the database ** structure? */ sqlite3DbFree(db, db->aDb[1].pSchema); sqlite3_mutex_leave(db->mutex); db->magic = SQLITE_MAGIC_CLOSED; sqlite3_mutex_free(db->mutex); assert( sqlite3LookasideUsed(db,0)==0 ); if( db->lookaside.bMalloced ){ sqlite3_free(db->lookaside.pStart); } sqlite3_free(db); } /* |
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Changes to src/malloc.c.
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350 351 352 353 354 355 356 | LookasideSlot *pBuf = (LookasideSlot*)p; #ifdef SQLITE_DEBUG /* Trash all content in the buffer being freed */ memset(p, 0xaa, db->lookaside.sz); #endif pBuf->pNext = db->lookaside.pFree; db->lookaside.pFree = pBuf; | < | 350 351 352 353 354 355 356 357 358 359 360 361 362 363 | LookasideSlot *pBuf = (LookasideSlot*)p; #ifdef SQLITE_DEBUG /* Trash all content in the buffer being freed */ memset(p, 0xaa, db->lookaside.sz); #endif pBuf->pNext = db->lookaside.pFree; db->lookaside.pFree = pBuf; return; } } assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) ); assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) ); assert( db!=0 || sqlite3MemdebugNoType(p, MEMTYPE_LOOKASIDE) ); sqlite3MemdebugSetType(p, MEMTYPE_HEAP); |
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511 512 513 514 515 516 517 | assert( db!=0 ); assert( sqlite3_mutex_held(db->mutex) ); assert( db->pnBytesFreed==0 ); if( db->lookaside.bDisable==0 ){ assert( db->mallocFailed==0 ); if( n>db->lookaside.sz ){ db->lookaside.anStat[1]++; | | < < | > | | | < > > | 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 | assert( db!=0 ); assert( sqlite3_mutex_held(db->mutex) ); assert( db->pnBytesFreed==0 ); if( db->lookaside.bDisable==0 ){ assert( db->mallocFailed==0 ); if( n>db->lookaside.sz ){ db->lookaside.anStat[1]++; }else if( (pBuf = db->lookaside.pFree)!=0 ){ db->lookaside.pFree = pBuf->pNext; db->lookaside.anStat[0]++; return (void*)pBuf; }else if( (pBuf = db->lookaside.pInit)!=0 ){ db->lookaside.pInit = pBuf->pNext; db->lookaside.anStat[0]++; return (void*)pBuf; }else{ db->lookaside.anStat[2]++; } }else if( db->mallocFailed ){ return 0; } #else assert( db!=0 ); assert( sqlite3_mutex_held(db->mutex) ); |
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Changes to src/sqliteInt.h.
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1241 1242 1243 1244 1245 1246 1247 | ** schema information, the Lookaside.bEnabled flag is cleared so that ** lookaside allocations are not used to construct the schema objects. */ struct Lookaside { u32 bDisable; /* Only operate the lookaside when zero */ u16 sz; /* Size of each buffer in bytes */ u8 bMalloced; /* True if pStart obtained from sqlite3_malloc() */ | < | | > | 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 | ** schema information, the Lookaside.bEnabled flag is cleared so that ** lookaside allocations are not used to construct the schema objects. */ struct Lookaside { u32 bDisable; /* Only operate the lookaside when zero */ u16 sz; /* Size of each buffer in bytes */ u8 bMalloced; /* True if pStart obtained from sqlite3_malloc() */ u32 nSlot; /* Number of lookaside slots allocated */ u32 anStat[3]; /* 0: hits. 1: size misses. 2: full misses */ LookasideSlot *pInit; /* List of buffers not previously used */ LookasideSlot *pFree; /* List of available buffers */ void *pStart; /* First byte of available memory space */ void *pEnd; /* First byte past end of available space */ }; struct LookasideSlot { LookasideSlot *pNext; /* Next buffer in the list of free buffers */ }; |
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3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 | # define sqlite3MemoryBarrier() #endif sqlite3_int64 sqlite3StatusValue(int); void sqlite3StatusUp(int, int); void sqlite3StatusDown(int, int); void sqlite3StatusHighwater(int, int); /* Access to mutexes used by sqlite3_status() */ sqlite3_mutex *sqlite3Pcache1Mutex(void); sqlite3_mutex *sqlite3MallocMutex(void); #ifndef SQLITE_OMIT_FLOATING_POINT int sqlite3IsNaN(double); | > | 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 | # define sqlite3MemoryBarrier() #endif sqlite3_int64 sqlite3StatusValue(int); void sqlite3StatusUp(int, int); void sqlite3StatusDown(int, int); void sqlite3StatusHighwater(int, int); int sqlite3LookasideUsed(sqlite3*,int*); /* Access to mutexes used by sqlite3_status() */ sqlite3_mutex *sqlite3Pcache1Mutex(void); sqlite3_mutex *sqlite3MallocMutex(void); #ifndef SQLITE_OMIT_FLOATING_POINT int sqlite3IsNaN(double); |
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Changes to src/status.c.
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165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 | rc = sqlite3_status64(op, &iCur, &iHwtr, resetFlag); if( rc==0 ){ *pCurrent = (int)iCur; *pHighwater = (int)iHwtr; } return rc; } /* ** Query status information for a single database connection */ int sqlite3_db_status( sqlite3 *db, /* The database connection whose status is desired */ int op, /* Status verb */ int *pCurrent, /* Write current value here */ int *pHighwater, /* Write high-water mark here */ int resetFlag /* Reset high-water mark if true */ ){ int rc = SQLITE_OK; /* Return code */ #ifdef SQLITE_ENABLE_API_ARMOR if( !sqlite3SafetyCheckOk(db) || pCurrent==0|| pHighwater==0 ){ return SQLITE_MISUSE_BKPT; } #endif sqlite3_mutex_enter(db->mutex); switch( op ){ case SQLITE_DBSTATUS_LOOKASIDE_USED: { | > > > > > > > > > > > > > > > > > > > > > > | < > > > > > | > | 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 | rc = sqlite3_status64(op, &iCur, &iHwtr, resetFlag); if( rc==0 ){ *pCurrent = (int)iCur; *pHighwater = (int)iHwtr; } return rc; } /* ** Return the number of LookasideSlot elements on the linked list */ static u32 countLookasideSlots(LookasideSlot *p){ u32 cnt = 0; while( p ){ p = p->pNext; cnt++; } return cnt; } /* ** Count the number of slots of lookaside memory that are outstanding */ int sqlite3LookasideUsed(sqlite3 *db, int *pHighwater){ u32 nInit = countLookasideSlots(db->lookaside.pInit); u32 nFree = countLookasideSlots(db->lookaside.pFree); if( pHighwater ) *pHighwater = db->lookaside.nSlot - nInit; return db->lookaside.nSlot - (nInit+nFree); } /* ** Query status information for a single database connection */ int sqlite3_db_status( sqlite3 *db, /* The database connection whose status is desired */ int op, /* Status verb */ int *pCurrent, /* Write current value here */ int *pHighwater, /* Write high-water mark here */ int resetFlag /* Reset high-water mark if true */ ){ int rc = SQLITE_OK; /* Return code */ #ifdef SQLITE_ENABLE_API_ARMOR if( !sqlite3SafetyCheckOk(db) || pCurrent==0|| pHighwater==0 ){ return SQLITE_MISUSE_BKPT; } #endif sqlite3_mutex_enter(db->mutex); switch( op ){ case SQLITE_DBSTATUS_LOOKASIDE_USED: { *pCurrent = sqlite3LookasideUsed(db, pHighwater); if( resetFlag ){ LookasideSlot *p = db->lookaside.pFree; if( p ){ while( p->pNext ) p = p->pNext; p->pNext = db->lookaside.pInit; db->lookaside.pInit = db->lookaside.pFree; db->lookaside.pFree = 0; } } break; } case SQLITE_DBSTATUS_LOOKASIDE_HIT: case SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE: case SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL: { |
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