Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
| Comment: | Use tail recursion in pcache1Unpin() to get a small size reduction and speed improvement. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
fde70472aebc09b34a517131f676e684 |
| User & Date: | drh 2015-06-29 00:21:00 |
Context
|
2015-06-29
| ||
| 00:52 | Move an assert() and testcase() into their correct position within getAndInitPage(). (check-in: 18115164 user: drh tags: trunk) | |
| 00:21 | Use tail recursion in pcache1Unpin() to get a small size reduction and speed improvement. (check-in: fde70472 user: drh tags: trunk) | |
|
2015-06-28
| ||
| 17:33 | Comment typo fix and minor cleanup in the pager. No logic changes. (check-in: 94ef1701 user: drh tags: trunk) | |
Changes
Changes to src/pcache1.c.
458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 ... 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 ... 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 .... 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 |
return pPage;
}
/*
** Remove the page supplied as an argument from the hash table
** (PCache1.apHash structure) that it is currently stored in.
**
** The PGroup mutex must be held when this function is called.
*/
static void pcache1RemoveFromHash(PgHdr1 *pPage){
unsigned int h;
PCache1 *pCache = pPage->pCache;
PgHdr1 **pp;
assert( sqlite3_mutex_held(pCache->pGroup->mutex) );
h = pPage->iKey % pCache->nHash;
for(pp=&pCache->apHash[h]; (*pp)!=pPage; pp=&(*pp)->pNext);
*pp = (*pp)->pNext;
pCache->nPage--;
}
/*
** If there are currently more than nMaxPage pages allocated, try
** to recycle pages to reduce the number allocated to nMaxPage.
*/
static void pcache1EnforceMaxPage(PGroup *pGroup){
assert( sqlite3_mutex_held(pGroup->mutex) );
while( pGroup->nCurrentPage>pGroup->nMaxPage && pGroup->pLruTail ){
PgHdr1 *p = pGroup->pLruTail;
assert( p->pCache->pGroup==pGroup );
assert( p->isPinned==0 );
pcache1PinPage(p);
pcache1RemoveFromHash(p);
pcache1FreePage(p);
}
}
/*
** Discard all pages from cache pCache with a page number (key value)
** greater than or equal to iLimit. Any pinned pages that meet this
** criteria are unpinned before they are discarded.
................................................................................
(pCache->nPage+1>=pCache->nMax)
|| pGroup->nCurrentPage>=pGroup->nMaxPage
|| pcache1UnderMemoryPressure(pCache)
)){
PCache1 *pOther;
pPage = pGroup->pLruTail;
assert( pPage->isPinned==0 );
pcache1RemoveFromHash(pPage);
pcache1PinPage(pPage);
pOther = pPage->pCache;
/* We want to verify that szPage and szExtra are the same for pOther
** and pCache. Assert that we can verify this by comparing sums. */
assert( (pCache->szPage & (pCache->szPage-1))==0 && pCache->szPage>=512 );
assert( pCache->szExtra<512 );
................................................................................
** part of the PGroup LRU list.
*/
assert( pPage->pLruPrev==0 && pPage->pLruNext==0 );
assert( pGroup->pLruHead!=pPage && pGroup->pLruTail!=pPage );
assert( pPage->isPinned==1 );
if( reuseUnlikely || pGroup->nCurrentPage>pGroup->nMaxPage ){
pcache1RemoveFromHash(pPage);
pcache1FreePage(pPage);
}else{
/* Add the page to the PGroup LRU list. */
if( pGroup->pLruHead ){
pGroup->pLruHead->pLruPrev = pPage;
pPage->pLruNext = pGroup->pLruHead;
pGroup->pLruHead = pPage;
}else{
................................................................................
while( (nReq<0 || nFree<nReq) && ((p=pcache1.grp.pLruTail)!=0) ){
nFree += pcache1MemSize(p->page.pBuf);
#ifdef SQLITE_PCACHE_SEPARATE_HEADER
nFree += sqlite3MemSize(p);
#endif
assert( p->isPinned==0 );
pcache1PinPage(p);
pcache1RemoveFromHash(p);
pcache1FreePage(p);
}
pcache1LeaveMutex(&pcache1.grp);
}
return nFree;
}
#endif /* SQLITE_ENABLE_MEMORY_MANAGEMENT */
|
> | > | < | | < | < |
458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 ... 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 ... 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 .... 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 |
return pPage; } /* ** Remove the page supplied as an argument from the hash table ** (PCache1.apHash structure) that it is currently stored in. ** Also free the page if freePage is true. ** ** The PGroup mutex must be held when this function is called. */ static void pcache1RemoveFromHash(PgHdr1 *pPage, int freeFlag){ unsigned int h; PCache1 *pCache = pPage->pCache; PgHdr1 **pp; assert( sqlite3_mutex_held(pCache->pGroup->mutex) ); h = pPage->iKey % pCache->nHash; for(pp=&pCache->apHash[h]; (*pp)!=pPage; pp=&(*pp)->pNext); *pp = (*pp)->pNext; pCache->nPage--; if( freeFlag ) pcache1FreePage(pPage); } /* ** If there are currently more than nMaxPage pages allocated, try ** to recycle pages to reduce the number allocated to nMaxPage. */ static void pcache1EnforceMaxPage(PGroup *pGroup){ assert( sqlite3_mutex_held(pGroup->mutex) ); while( pGroup->nCurrentPage>pGroup->nMaxPage && pGroup->pLruTail ){ PgHdr1 *p = pGroup->pLruTail; assert( p->pCache->pGroup==pGroup ); assert( p->isPinned==0 ); pcache1PinPage(p); pcache1RemoveFromHash(p, 1); } } /* ** Discard all pages from cache pCache with a page number (key value) ** greater than or equal to iLimit. Any pinned pages that meet this ** criteria are unpinned before they are discarded. ................................................................................ (pCache->nPage+1>=pCache->nMax) || pGroup->nCurrentPage>=pGroup->nMaxPage || pcache1UnderMemoryPressure(pCache) )){ PCache1 *pOther; pPage = pGroup->pLruTail; assert( pPage->isPinned==0 ); pcache1RemoveFromHash(pPage, 0); pcache1PinPage(pPage); pOther = pPage->pCache; /* We want to verify that szPage and szExtra are the same for pOther ** and pCache. Assert that we can verify this by comparing sums. */ assert( (pCache->szPage & (pCache->szPage-1))==0 && pCache->szPage>=512 ); assert( pCache->szExtra<512 ); ................................................................................ ** part of the PGroup LRU list. */ assert( pPage->pLruPrev==0 && pPage->pLruNext==0 ); assert( pGroup->pLruHead!=pPage && pGroup->pLruTail!=pPage ); assert( pPage->isPinned==1 ); if( reuseUnlikely || pGroup->nCurrentPage>pGroup->nMaxPage ){ pcache1RemoveFromHash(pPage, 1); }else{ /* Add the page to the PGroup LRU list. */ if( pGroup->pLruHead ){ pGroup->pLruHead->pLruPrev = pPage; pPage->pLruNext = pGroup->pLruHead; pGroup->pLruHead = pPage; }else{ ................................................................................ while( (nReq<0 || nFree<nReq) && ((p=pcache1.grp.pLruTail)!=0) ){ nFree += pcache1MemSize(p->page.pBuf); #ifdef SQLITE_PCACHE_SEPARATE_HEADER nFree += sqlite3MemSize(p); #endif assert( p->isPinned==0 ); pcache1PinPage(p); pcache1RemoveFromHash(p, 1); } pcache1LeaveMutex(&pcache1.grp); } return nFree; } #endif /* SQLITE_ENABLE_MEMORY_MANAGEMENT */ |