Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
| Comment: | Avoid unnecessary mutex usage in pcache1, for a significant speedup. |
|---|---|
| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | faster-pcache1-fetch |
| Files: | files | file ages | folders |
| SHA1: |
dcf4fb8d764611de60afea27cda0a854 |
| User & Date: | drh 2015-06-13 11:10:55.570 |
Context
|
2015-06-13
| ||
| 11:19 | Omit mutex calls in pcache1 when the mutex is NULL, for a significant performance improvement. (check-in: caf8f574e5 user: drh tags: trunk) | |
| 11:10 | Avoid unnecessary mutex usage in pcache1, for a significant speedup. (Closed-Leaf check-in: dcf4fb8d76 user: drh tags: faster-pcache1-fetch) | |
|
2015-06-12
| ||
| 13:49 | Add a fast-path implementation of pcache1Fetch() for the common case of separate caches that do not use a mutex. (check-in: 760700edb3 user: drh tags: faster-pcache1-fetch) | |
Changes
Changes to src/pcache1.c.
| ︙ | ︙ | |||
144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 | ** 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. */ #define pcache1EnterMutex(X) sqlite3_mutex_enter((X)->mutex) #define pcache1LeaveMutex(X) sqlite3_mutex_leave((X)->mutex) /******************************************************************************/ /******** 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 | > > > > > > > | 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 |
| ︙ | ︙ | |||
525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 |
/*
** 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.
|
| ︙ | ︙ | |||
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 |
}else if( createFlag ){
/* Steps 3, 4, and 5 implemented by this subroutine */
return pcache1FetchStage2(pCache, iKey, createFlag);
}else{
return 0;
}
}
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;
}
static sqlite3_pcache_page *pcache1Fetch(
sqlite3_pcache *p,
unsigned int iKey,
int createFlag
){
PCache1 *pCache = (PCache1 *)p;
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( pCache->pGroup->mutex ){
return (sqlite3_pcache_page*)pcache1FetchWithMutex(p, iKey, createFlag);
| > > > > > | > > | 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 |
}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.
|
| ︙ | ︙ |