Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
Comment: | Fix a performance regression: Keep two btree masks in each prepared statement; one for btrees used and another for btrees that require locks. Only try to lock the btrees identified by the second mask. |
---|---|
Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
614de91a504d2231009a9de1305e31fc |
User & Date: | drh 2011-04-06 22:05:53.025 |
Context
2011-04-07
| ||
01:14 | Fix typos in documentation comments. No changes to code. (check-in: 9c64b5a99c user: drh tags: trunk) | |
2011-04-06
| ||
22:33 | Merge in the latest changes from the trunk. (check-in: 435b57dc2b user: drh tags: sessions) | |
22:05 | Fix a performance regression: Keep two btree masks in each prepared statement; one for btrees used and another for btrees that require locks. Only try to lock the btrees identified by the second mask. (check-in: 614de91a50 user: drh tags: trunk) | |
19:15 | Fix a benign inaccuracy in the os_unix.c SQLITE_FCNTL_SIZE_HINT code. (check-in: 61a6ccbe3c user: dan tags: trunk) | |
Changes
Changes to src/btmutex.c.
︙ | ︙ | |||
198 199 200 201 202 203 204 205 206 207 208 209 210 211 | Btree *p; assert( sqlite3_mutex_held(db->mutex) ); for(i=0; i<db->nDb; i++){ p = db->aDb[i].pBt; if( p ) sqlite3BtreeLeave(p); } } #ifndef NDEBUG /* ** Return true if the current thread holds the database connection ** mutex and all required BtShared mutexes. ** ** This routine is used inside assert() statements only. | > > > > > > > > | 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 | Btree *p; assert( sqlite3_mutex_held(db->mutex) ); for(i=0; i<db->nDb; i++){ p = db->aDb[i].pBt; if( p ) sqlite3BtreeLeave(p); } } /* ** Return true if a particular Btree requires a lock. Return FALSE if ** no lock is ever required since it is not sharable. */ int sqlite3BtreeSharable(Btree *p){ return p->sharable; } #ifndef NDEBUG /* ** Return true if the current thread holds the database connection ** mutex and all required BtShared mutexes. ** ** This routine is used inside assert() statements only. |
︙ | ︙ |
Changes to src/btree.h.
︙ | ︙ | |||
208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 | void sqlite3BtreeEnterAll(sqlite3*); #else # define sqlite3BtreeEnter(X) # define sqlite3BtreeEnterAll(X) #endif #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE void sqlite3BtreeLeave(Btree*); void sqlite3BtreeEnterCursor(BtCursor*); void sqlite3BtreeLeaveCursor(BtCursor*); void sqlite3BtreeLeaveAll(sqlite3*); #ifndef NDEBUG /* These routines are used inside assert() statements only. */ int sqlite3BtreeHoldsMutex(Btree*); int sqlite3BtreeHoldsAllMutexes(sqlite3*); int sqlite3SchemaMutexHeld(sqlite3*,int,Schema*); #endif #else # define sqlite3BtreeLeave(X) # define sqlite3BtreeEnterCursor(X) # define sqlite3BtreeLeaveCursor(X) # define sqlite3BtreeLeaveAll(X) # define sqlite3BtreeHoldsMutex(X) 1 # define sqlite3BtreeHoldsAllMutexes(X) 1 | > > | 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 | void sqlite3BtreeEnterAll(sqlite3*); #else # define sqlite3BtreeEnter(X) # define sqlite3BtreeEnterAll(X) #endif #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE int sqlite3BtreeSharable(Btree*); void sqlite3BtreeLeave(Btree*); void sqlite3BtreeEnterCursor(BtCursor*); void sqlite3BtreeLeaveCursor(BtCursor*); void sqlite3BtreeLeaveAll(sqlite3*); #ifndef NDEBUG /* These routines are used inside assert() statements only. */ int sqlite3BtreeHoldsMutex(Btree*); int sqlite3BtreeHoldsAllMutexes(sqlite3*); int sqlite3SchemaMutexHeld(sqlite3*,int,Schema*); #endif #else # define sqlite3BtreeSharable(X) 0 # define sqlite3BtreeLeave(X) # define sqlite3BtreeEnterCursor(X) # define sqlite3BtreeLeaveCursor(X) # define sqlite3BtreeLeaveAll(X) # define sqlite3BtreeHoldsMutex(X) 1 # define sqlite3BtreeHoldsAllMutexes(X) 1 |
︙ | ︙ |
Changes to src/vdbe.c.
︙ | ︙ | |||
4641 4642 4643 4644 4645 4646 4647 | ** sqlite3InitCallback(). */ #ifdef SQLITE_DEBUG for(iDb=0; iDb<db->nDb; iDb++){ assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) ); } #endif | < < | 4641 4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652 4653 4654 | ** sqlite3InitCallback(). */ #ifdef SQLITE_DEBUG for(iDb=0; iDb<db->nDb; iDb++){ assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) ); } #endif iDb = pOp->p1; assert( iDb>=0 && iDb<db->nDb ); assert( DbHasProperty(db, iDb, DB_SchemaLoaded) ); /* Used to be a conditional */ { zMaster = SCHEMA_TABLE(iDb); initData.db = db; |
︙ | ︙ |
Changes to src/vdbeInt.h.
︙ | ︙ | |||
299 300 301 302 303 304 305 306 307 308 309 310 311 312 | u8 minWriteFileFormat; /* Minimum file format for writable database files */ u8 inVtabMethod; /* See comments above */ u8 usesStmtJournal; /* True if uses a statement journal */ u8 readOnly; /* True for read-only statements */ u8 isPrepareV2; /* True if prepared with prepare_v2() */ int nChange; /* Number of db changes made since last reset */ yDbMask btreeMask; /* Bitmask of db->aDb[] entries referenced */ int iStatement; /* Statement number (or 0 if has not opened stmt) */ int aCounter[3]; /* Counters used by sqlite3_stmt_status() */ #ifndef SQLITE_OMIT_TRACE i64 startTime; /* Time when query started - used for profiling */ #endif i64 nFkConstraint; /* Number of imm. FK constraints this VM */ i64 nStmtDefCons; /* Number of def. constraints when stmt started */ | > | 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 | u8 minWriteFileFormat; /* Minimum file format for writable database files */ u8 inVtabMethod; /* See comments above */ u8 usesStmtJournal; /* True if uses a statement journal */ u8 readOnly; /* True for read-only statements */ u8 isPrepareV2; /* True if prepared with prepare_v2() */ int nChange; /* Number of db changes made since last reset */ yDbMask btreeMask; /* Bitmask of db->aDb[] entries referenced */ yDbMask lockMask; /* Subset of btreeMask that requires a lock */ int iStatement; /* Statement number (or 0 if has not opened stmt) */ int aCounter[3]; /* Counters used by sqlite3_stmt_status() */ #ifndef SQLITE_OMIT_TRACE i64 startTime; /* Time when query started - used for profiling */ #endif i64 nFkConstraint; /* Number of imm. FK constraints this VM */ i64 nStmtDefCons; /* Number of def. constraints when stmt started */ |
︙ | ︙ |
Changes to src/vdbeaux.c.
︙ | ︙ | |||
156 157 158 159 160 161 162 | pOp->p3 = p3; pOp->p4.p = 0; pOp->p4type = P4_NOTUSED; p->expired = 0; if( op==OP_ParseSchema ){ /* Any program that uses the OP_ParseSchema opcode needs to lock ** all btrees. */ | | > | 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 | pOp->p3 = p3; pOp->p4.p = 0; pOp->p4type = P4_NOTUSED; p->expired = 0; if( op==OP_ParseSchema ){ /* Any program that uses the OP_ParseSchema opcode needs to lock ** all btrees. */ int j; for(j=0; j<p->db->nDb; j++) sqlite3VdbeUsesBtree(p, j); } #ifdef SQLITE_DEBUG pOp->zComment = 0; if( sqlite3VdbeAddopTrace ) sqlite3VdbePrintOp(0, i, &p->aOp[i]); #endif #ifdef VDBE_PROFILE pOp->cycles = 0; |
︙ | ︙ | |||
954 955 956 957 958 959 960 961 962 963 964 965 966 967 | ** attached databases that they will be using. A mask of these databases ** is maintained in p->btreeMask and is used for locking and other purposes. */ void sqlite3VdbeUsesBtree(Vdbe *p, int i){ assert( i>=0 && i<p->db->nDb && i<(int)sizeof(yDbMask)*8 ); assert( i<(int)sizeof(p->btreeMask)*8 ); p->btreeMask |= ((yDbMask)1)<<i; } #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0 /* ** If SQLite is compiled to support shared-cache mode and to be threadsafe, ** this routine obtains the mutex associated with each BtShared structure ** that may be accessed by the VM passed as an argument. In doing so it also | > > > | 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 | ** attached databases that they will be using. A mask of these databases ** is maintained in p->btreeMask and is used for locking and other purposes. */ void sqlite3VdbeUsesBtree(Vdbe *p, int i){ assert( i>=0 && i<p->db->nDb && i<(int)sizeof(yDbMask)*8 ); assert( i<(int)sizeof(p->btreeMask)*8 ); p->btreeMask |= ((yDbMask)1)<<i; if( i!=1 && sqlite3BtreeSharable(p->db->aDb[i].pBt) ){ p->lockMask |= ((yDbMask)1)<<i; } } #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0 /* ** If SQLite is compiled to support shared-cache mode and to be threadsafe, ** this routine obtains the mutex associated with each BtShared structure ** that may be accessed by the VM passed as an argument. In doing so it also |
︙ | ︙ | |||
981 982 983 984 985 986 987 | ** corresponding to btrees that use shared cache. Then the runtime of ** this routine is N*N. But as N is rarely more than 1, this should not ** be a problem. */ void sqlite3VdbeEnter(Vdbe *p){ int i; yDbMask mask; | | > > > > | | | | | | | > > > | | 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 | ** corresponding to btrees that use shared cache. Then the runtime of ** this routine is N*N. But as N is rarely more than 1, this should not ** be a problem. */ void sqlite3VdbeEnter(Vdbe *p){ int i; yDbMask mask; sqlite3 *db; Db *aDb; int nDb; if( p->lockMask==0 ) return; /* The common case */ db = p->db; aDb = db->aDb; nDb = db->nDb; for(i=0, mask=1; i<nDb; i++, mask += mask){ if( i!=1 && (mask & p->lockMask)!=0 && ALWAYS(aDb[i].pBt!=0) ){ sqlite3BtreeEnter(aDb[i].pBt); } } } #endif #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0 /* ** Unlock all of the btrees previously locked by a call to sqlite3VdbeEnter(). */ void sqlite3VdbeLeave(Vdbe *p){ int i; yDbMask mask; sqlite3 *db; Db *aDb; int nDb; if( p->lockMask==0 ) return; /* The common case */ db = p->db; aDb = db->aDb; nDb = db->nDb; for(i=0, mask=1; i<nDb; i++, mask += mask){ if( i!=1 && (mask & p->lockMask)!=0 && ALWAYS(aDb[i].pBt!=0) ){ sqlite3BtreeLeave(aDb[i].pBt); } } } #endif #if defined(VDBE_PROFILE) || defined(SQLITE_DEBUG) |
︙ | ︙ |