Index: src/pcache1.c ================================================================== --- src/pcache1.c +++ src/pcache1.c @@ -20,10 +20,41 @@ #include "sqliteInt.h" typedef struct PCache1 PCache1; typedef struct PgHdr1 PgHdr1; typedef struct PgFreeslot PgFreeslot; +typedef struct PGroup PGroup; + +/* Each page cache (or PCache) belongs to a PGroup. A PGroup is a set +** of one or more PCaches that are able to recycle each others unpinned +** pages when they are under memory pressure. A PGroup is an instance of +** the following object. +** +** This page cache implementation works in one of two modes: +** +** (1) Every PCache is the sole member of its own PGroup. There is +** one PGroup per PCache. +** +** (2) There is a single global PGroup that all PCaches are a member +** of. +** +** Mode 1 uses more memory (since PCache instances are not able to rob +** unused pages from other PCaches) but it also operates without a mutex, +** and is therefore often faster. Mode 2 requires a mutex in order to be +** threadsafe, but is able recycle pages more efficient. +** +** For mode (1), PGroup.mutex is NULL. For mode (2) there is only a single +** PGroup which is the pcache1.grp global variable and its mutex is +** SQLITE_MUTEX_STATIC_LRU. +*/ +struct PGroup { + sqlite3_mutex *mutex; /* MUTEX_STATIC_LRU or NULL */ + int nMaxPage; /* Sum of nMax for purgeable caches */ + int nMinPage; /* Sum of nMin for purgeable caches */ + int nCurrentPage; /* Number of purgeable pages allocated */ + PgHdr1 *pLruHead, *pLruTail; /* LRU list of unpinned pages */ +}; /* Each page cache is an instance of the following object. Every ** open database file (including each in-memory database and each ** temporary or transient database) has a single page cache which ** is an instance of this object. @@ -33,20 +64,20 @@ */ struct PCache1 { /* Cache configuration parameters. Page size (szPage) and the purgeable ** flag (bPurgeable) are set when the cache is created. nMax may be ** modified at any time by a call to the pcache1CacheSize() method. - ** The global mutex must be held when accessing nMax. + ** The PGroup mutex must be held when accessing nMax. */ + PGroup *pGroup; /* PGroup this cache belongs to */ int szPage; /* Size of allocated pages in bytes */ int bPurgeable; /* True if cache is purgeable */ unsigned int nMin; /* Minimum number of pages reserved */ unsigned int nMax; /* Configured "cache_size" value */ /* Hash table of all pages. The following variables may only be accessed - ** when the accessor is holding the global mutex (see pcache1EnterMutex() - ** and pcache1LeaveMutex()). + ** when the accessor is holding the PGroup mutex. */ unsigned int nRecyclable; /* Number of pages in the LRU list */ unsigned int nPage; /* Total number of pages in apHash */ unsigned int nHash; /* Number of slots in apHash[] */ PgHdr1 **apHash; /* Hash table for fast lookup by key */ @@ -78,25 +109,31 @@ /* ** Global data used by this cache. */ static SQLITE_WSD struct PCacheGlobal { - sqlite3_mutex *mutex; /* static mutex MUTEX_STATIC_LRU */ - - int nMaxPage; /* Sum of nMaxPage for purgeable caches */ - int nMinPage; /* Sum of nMinPage for purgeable caches */ - int nCurrentPage; /* Number of purgeable pages allocated */ - PgHdr1 *pLruHead, *pLruTail; /* LRU list of unpinned pages */ - - /* Variables related to SQLITE_CONFIG_PAGECACHE settings. */ - int szSlot; /* Size of each free slot */ - int nSlot; /* The number of pcache slots */ - int nFreeSlot; /* Number of unused pcache slots */ - int nReserve; /* Try to keep nFreeSlot above this */ - void *pStart, *pEnd; /* Bounds of pagecache malloc range */ - PgFreeslot *pFree; /* Free page blocks */ - int isInit; /* True if initialized */ + PGroup grp; /* The global PGroup for mode (2) */ + + /* Variables related to SQLITE_CONFIG_PAGECACHE settings. The + ** szSlot, nSlot, pStart, pEnd, nReserve, and isInit values are all + ** fixed at sqlite3_initialize() time and do not require mutex protection. + ** The nFreeSlot and pFree values do require mutex protection. + */ + int isInit; /* True if initialized */ + int szSlot; /* Size of each free slot */ + int nSlot; /* The number of pcache slots */ + int nReserve; /* Try to keep nFreeSlot above this */ + void *pStart, *pEnd; /* Bounds of pagecache malloc range */ + /* Above requires no mutex. Use mutex below for variable that follow. */ + sqlite3_mutex *mutex; /* Mutex for accessing the following: */ + int nFreeSlot; /* Number of unused pcache slots */ + PgFreeslot *pFree; /* Free page blocks */ + /* The following value requires a mutex to change. We skip the mutex on + ** reading because (1) most platforms read a 32-bit integer atomically and + ** (2) even if an incorrect value is read, no great harm is done since this + ** is really just an optimization. */ + int bUnderPressure; /* True if low on PAGECACHE memory */ } pcache1_g; /* ** All code in this file should access the global structure above via the ** alias "pcache1". This ensures that the WSD emulation is used when @@ -118,23 +155,26 @@ */ #define PGHDR1_TO_PAGE(p) (void*)(((char*)p) - p->pCache->szPage) #define PAGE_TO_PGHDR1(c, p) (PgHdr1*)(((char*)p) + c->szPage) /* -** Macros to enter and leave the global LRU mutex. +** Macros to enter and leave the PCache LRU mutex. */ -#define pcache1EnterMutex() sqlite3_mutex_enter(pcache1.mutex) -#define pcache1LeaveMutex() sqlite3_mutex_leave(pcache1.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 ** verb to sqlite3_config(). Parameter pBuf points to an allocation large ** enough to contain 'n' buffers of 'sz' bytes each. +** +** This routine is called from sqlite3_initialize() and so it is guaranteed +** to be serialized already. There is no need for further mutexing. */ void sqlite3PCacheBufferSetup(void *pBuf, int sz, int n){ if( pcache1.isInit ){ PgFreeslot *p; sz = ROUNDDOWN8(sz); @@ -141,10 +181,11 @@ pcache1.szSlot = sz; pcache1.nSlot = pcache1.nFreeSlot = n; pcache1.nReserve = n>90 ? 10 : (n/10 + 1); pcache1.pStart = pBuf; pcache1.pFree = 0; + pcache1.bUnderPressure = 0; while( n-- ){ p = (PgFreeslot*)pBuf; p->pNext = pcache1.pFree; pcache1.pFree = p; pBuf = (void*)&((char*)pBuf)[sz]; @@ -156,33 +197,35 @@ /* ** Malloc function used within this file to allocate space from the buffer ** configured using sqlite3_config(SQLITE_CONFIG_PAGECACHE) option. If no ** such buffer exists or there is no space left in it, this function falls ** back to sqlite3Malloc(). +** +** Multiple threads can run this routine at the same time. Global variables +** in pcache1 need to be protected via mutex. */ static void *pcache1Alloc(int nByte){ - void *p; - assert( sqlite3_mutex_held(pcache1.mutex) ); + void *p = 0; + assert( sqlite3_mutex_notheld(pcache1.grp.mutex) ); sqlite3StatusSet(SQLITE_STATUS_PAGECACHE_SIZE, nByte); - if( nByte<=pcache1.szSlot && pcache1.pFree ){ - assert( pcache1.isInit ); + if( nByte<=pcache1.szSlot ){ + sqlite3_mutex_enter(pcache1.mutex); p = (PgHdr1 *)pcache1.pFree; - pcache1.pFree = pcache1.pFree->pNext; - pcache1.nFreeSlot--; - assert( pcache1.nFreeSlot>=0 ); - sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_USED, 1); - }else{ - - /* Allocate a new buffer using sqlite3Malloc. Before doing so, exit the - ** global pcache mutex and unlock the pager-cache object pCache. This is - ** so that if the attempt to allocate a new buffer causes the the - ** configured soft-heap-limit to be breached, it will be possible to - ** reclaim memory from this pager-cache. + if( p ){ + pcache1.pFree = pcache1.pFree->pNext; + pcache1.nFreeSlot--; + pcache1.bUnderPressure = pcache1.nFreeSlot=0 ); + sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_USED, 1); + } + sqlite3_mutex_leave(pcache1.mutex); + } + if( p==0 ){ + /* Memory is not available in the SQLITE_CONFIG_PAGECACHE pool. Get + ** it from sqlite3Malloc instead. */ - pcache1LeaveMutex(); p = sqlite3Malloc(nByte); - pcache1EnterMutex(); if( p ){ int sz = sqlite3MallocSize(p); sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_OVERFLOW, sz); } sqlite3MemdebugSetType(p, MEMTYPE_PCACHE); @@ -192,20 +235,22 @@ /* ** Free an allocated buffer obtained from pcache1Alloc(). */ static void pcache1Free(void *p){ - assert( sqlite3_mutex_held(pcache1.mutex) ); if( p==0 ) return; if( p>=pcache1.pStart && ppNext = pcache1.pFree; pcache1.pFree = pSlot; pcache1.nFreeSlot++; + pcache1.bUnderPressure = pcache1.nFreeSlot=pcache1.pStart && pbPurgeable ){ - pcache1.nCurrentPage++; + pCache->pGroup->nCurrentPage++; } }else{ p = 0; } return p; @@ -258,12 +302,13 @@ ** that the current implementation happens to never call this routine ** with a NULL pointer, so we mark the NULL test with ALWAYS(). */ static void pcache1FreePage(PgHdr1 *p){ if( ALWAYS(p) ){ - if( p->pCache->bPurgeable ){ - pcache1.nCurrentPage--; + PCache1 *pCache = p->pCache; + if( pCache->bPurgeable ){ + pCache->pGroup->nCurrentPage--; } pcache1Free(PGHDR1_TO_PAGE(p)); } } @@ -271,24 +316,18 @@ ** Malloc function used by SQLite to obtain space from the buffer configured ** using sqlite3_config(SQLITE_CONFIG_PAGECACHE) option. If no such buffer ** exists, this function falls back to sqlite3Malloc(). */ void *sqlite3PageMalloc(int sz){ - void *p; - pcache1EnterMutex(); - p = pcache1Alloc(sz); - pcache1LeaveMutex(); - return p; + return pcache1Alloc(sz); } /* ** Free an allocated buffer obtained from sqlite3PageMalloc(). */ void sqlite3PageFree(void *p){ - pcache1EnterMutex(); pcache1Free(p); - pcache1LeaveMutex(); } /* ** Return true if it desirable to avoid allocating a new page cache @@ -305,13 +344,12 @@ ** under memory pressure, then again it is desirable to avoid ** allocating a new page cache entry in order to avoid stressing ** the heap even further. */ static int pcache1UnderMemoryPressure(PCache1 *pCache){ - assert( sqlite3_mutex_held(pcache1.mutex) ); if( pcache1.nSlot && pCache->szPage<=pcache1.szSlot ){ - return pcache1.nFreeSlotpGroup->mutex) ); nNew = p->nHash*2; if( nNew<256 ){ nNew = 256; } - pcache1LeaveMutex(); + pcache1LeaveMutex(p->pGroup); if( p->nHash ){ sqlite3BeginBenignMalloc(); } apNew = (PgHdr1 **)sqlite3_malloc(sizeof(PgHdr1 *)*nNew); if( p->nHash ){ sqlite3EndBenignMalloc(); } - pcache1EnterMutex(); + pcache1EnterMutex(p->pGroup); if( apNew ){ memset(apNew, 0, sizeof(PgHdr1 *)*nNew); for(i=0; inHash; i++){ PgHdr1 *pPage; PgHdr1 *pNext = p->apHash[i]; @@ -361,29 +399,37 @@ return (p->apHash ? SQLITE_OK : SQLITE_NOMEM); } /* ** This function is used internally to remove the page pPage from the -** global LRU list, if is part of it. If pPage is not part of the global +** 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 global mutex must be held when this function is called. +** The PGroup mutex must be held when this function is called. +** +** If pPage is NULL then this routine is a no-op. */ static void pcache1PinPage(PgHdr1 *pPage){ - assert( sqlite3_mutex_held(pcache1.mutex) ); - if( pPage && (pPage->pLruNext || pPage==pcache1.pLruTail) ){ + PCache1 *pCache; + PGroup *pGroup; + + if( pPage==0 ) return; + pCache = pPage->pCache; + pGroup = pCache->pGroup; + assert( sqlite3_mutex_held(pGroup->mutex) ); + if( pPage->pLruNext || pPage==pGroup->pLruTail ){ if( pPage->pLruPrev ){ pPage->pLruPrev->pLruNext = pPage->pLruNext; } if( pPage->pLruNext ){ pPage->pLruNext->pLruPrev = pPage->pLruPrev; } - if( pcache1.pLruHead==pPage ){ - pcache1.pLruHead = pPage->pLruNext; + if( pGroup->pLruHead==pPage ){ + pGroup->pLruHead = pPage->pLruNext; } - if( pcache1.pLruTail==pPage ){ - pcache1.pLruTail = pPage->pLruPrev; + if( pGroup->pLruTail==pPage ){ + pGroup->pLruTail = pPage->pLruPrev; } pPage->pLruNext = 0; pPage->pLruPrev = 0; pPage->pCache->nRecyclable--; } @@ -392,32 +438,34 @@ /* ** Remove the page supplied as an argument from the hash table ** (PCache1.apHash structure) that it is currently stored in. ** -** The global mutex must be held when this function is called. +** 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 pcache.nMaxPage pages allocated, try -** to recycle pages to reduce the number allocated to pcache.nMaxPage. +** If there are currently more than nMaxPage pages allocated, try +** to recycle pages to reduce the number allocated to nMaxPage. */ -static void pcache1EnforceMaxPage(void){ - assert( sqlite3_mutex_held(pcache1.mutex) ); - while( pcache1.nCurrentPage>pcache1.nMaxPage && pcache1.pLruTail ){ - PgHdr1 *p = pcache1.pLruTail; +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 ); pcache1PinPage(p); pcache1RemoveFromHash(p); pcache1FreePage(p); } } @@ -425,19 +473,19 @@ /* ** 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. ** -** The global mutex must be held when this function is called. +** The PCache mutex must be held when this function is called. */ static void pcache1TruncateUnsafe( - PCache1 *pCache, - unsigned int iLimit + PCache1 *pCache, /* The cache to truncate */ + unsigned int iLimit /* Drop pages with this pgno or larger */ ){ - TESTONLY( unsigned int nPage = 0; ) /* Used to assert pCache->nPage is correct */ + TESTONLY( unsigned int nPage = 0; ) /* To assert pCache->nPage is correct */ unsigned int h; - assert( sqlite3_mutex_held(pcache1.mutex) ); + assert( sqlite3_mutex_held(pCache->pGroup->mutex) ); for(h=0; hnHash; h++){ PgHdr1 **pp = &pCache->apHash[h]; PgHdr1 *pPage; while( (pPage = *pp)!=0 ){ if( pPage->iKey>=iLimit ){ @@ -463,11 +511,12 @@ static int pcache1Init(void *NotUsed){ UNUSED_PARAMETER(NotUsed); assert( pcache1.isInit==0 ); memset(&pcache1, 0, sizeof(pcache1)); if( sqlite3GlobalConfig.bCoreMutex ){ - pcache1.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_LRU); + pcache1.grp.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_LRU); + pcache1.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_PMEM); } pcache1.isInit = 1; return SQLITE_OK; } @@ -486,22 +535,49 @@ ** Implementation of the sqlite3_pcache.xCreate method. ** ** Allocate a new cache. */ static sqlite3_pcache *pcache1Create(int szPage, int bPurgeable){ - PCache1 *pCache; + PCache1 *pCache; /* The newly created page cache */ + PGroup *pGroup; /* The group the new page cache will belong to */ + int sz; /* Bytes of memory required to allocate the new cache */ + + /* + ** The seperateCache variable is true if each PCache has its own private + ** PGroup. In other words, separateCache is true for mode (1) where no + ** mutexing is required. + ** + ** * Always use a unified cache (mode-2) if ENABLE_MEMORY_MANAGEMENT + ** + ** * Always use a unified cache in single-threaded applications + ** + ** * Otherwise (if multi-threaded and ENABLE_MEMORY_MANAGEMENT is off) + ** use separate caches (mode-1) + */ +#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) || SQLITE_THREADSAFE==0 + const int separateCache = 0; +#else + int separateCache = sqlite3GlobalConfig.bCoreMutex>0; +#endif - pCache = (PCache1 *)sqlite3_malloc(sizeof(PCache1)); + sz = sizeof(PCache1) + sizeof(PGroup)*separateCache; + pCache = (PCache1 *)sqlite3_malloc(sz); if( pCache ){ - memset(pCache, 0, sizeof(PCache1)); + memset(pCache, 0, sz); + if( separateCache ){ + pGroup = (PGroup*)&pCache[1]; + }else{ + pGroup = &pcache1_g.grp; + } + pCache->pGroup = pGroup; pCache->szPage = szPage; pCache->bPurgeable = (bPurgeable ? 1 : 0); if( bPurgeable ){ pCache->nMin = 10; - pcache1EnterMutex(); - pcache1.nMinPage += pCache->nMin; - pcache1LeaveMutex(); + pcache1EnterMutex(pGroup); + pGroup->nMinPage += pCache->nMin; + pcache1LeaveMutex(pGroup); } } return (sqlite3_pcache *)pCache; } @@ -511,26 +587,28 @@ ** Configure the cache_size limit for a cache. */ static void pcache1Cachesize(sqlite3_pcache *p, int nMax){ PCache1 *pCache = (PCache1 *)p; if( pCache->bPurgeable ){ - pcache1EnterMutex(); - pcache1.nMaxPage += (nMax - pCache->nMax); + PGroup *pGroup = pCache->pGroup; + pcache1EnterMutex(pGroup); + pGroup->nMaxPage += (nMax - pCache->nMax); pCache->nMax = nMax; - pcache1EnforceMaxPage(); - pcache1LeaveMutex(); + pcache1EnforceMaxPage(pGroup); + pcache1LeaveMutex(pGroup); } } /* ** Implementation of the sqlite3_pcache.xPagecount method. */ static int pcache1Pagecount(sqlite3_pcache *p){ int n; - pcache1EnterMutex(); - n = ((PCache1 *)p)->nPage; - pcache1LeaveMutex(); + PCache1 *pCache = (PCache1*)p; + pcache1EnterMutex(pCache->pGroup); + n = pCache->nPage; + pcache1LeaveMutex(pCache->pGroup); return n; } /* ** Implementation of the sqlite3_pcache.xFetch method. @@ -587,14 +665,15 @@ ** 5. Otherwise, allocate and return a new page buffer. */ static void *pcache1Fetch(sqlite3_pcache *p, unsigned int iKey, int createFlag){ unsigned int nPinned; PCache1 *pCache = (PCache1 *)p; + PGroup *pGroup = pCache->pGroup; PgHdr1 *pPage = 0; assert( pCache->bPurgeable || createFlag!=1 ); - pcache1EnterMutex(); + pcache1EnterMutex(pGroup); if( createFlag==1 ) sqlite3BeginBenignMalloc(); /* Search the hash table for an existing entry. */ if( pCache->nHash>0 ){ unsigned int h = iKey % pCache->nHash; @@ -607,11 +686,11 @@ } /* Step 3 of header comment. */ nPinned = pCache->nPage - pCache->nRecyclable; if( createFlag==1 && ( - nPinned>=(pcache1.nMaxPage+pCache->nMin-pcache1.nMinPage) + nPinned>=(pGroup->nMaxPage+pCache->nMin-pGroup->nMinPage) || nPinned>=(pCache->nMax * 9 / 10) || pcache1UnderMemoryPressure(pCache) )){ goto fetch_out; } @@ -619,31 +698,34 @@ if( pCache->nPage>=pCache->nHash && pcache1ResizeHash(pCache) ){ goto fetch_out; } /* Step 4. Try to recycle a page buffer if appropriate. */ - if( pCache->bPurgeable && pcache1.pLruTail && ( + if( pCache->bPurgeable && pGroup->pLruTail && ( (pCache->nPage+1>=pCache->nMax) - || pcache1.nCurrentPage>=pcache1.nMaxPage + || pGroup->nCurrentPage>=pGroup->nMaxPage || pcache1UnderMemoryPressure(pCache) )){ - pPage = pcache1.pLruTail; + pPage = pGroup->pLruTail; pcache1RemoveFromHash(pPage); pcache1PinPage(pPage); if( pPage->pCache->szPage!=pCache->szPage ){ pcache1FreePage(pPage); pPage = 0; }else{ - pcache1.nCurrentPage -= (pPage->pCache->bPurgeable - pCache->bPurgeable); + pGroup->nCurrentPage -= + (pPage->pCache->bPurgeable - pCache->bPurgeable); } } /* Step 5. If a usable page buffer has still not been found, ** attempt to allocate a new one. */ if( !pPage ){ + pcache1LeaveMutex(pGroup); pPage = pcache1AllocPage(pCache); + pcache1EnterMutex(pGroup); } if( pPage ){ unsigned int h = iKey % pCache->nHash; pCache->nPage++; @@ -659,11 +741,11 @@ fetch_out: if( pPage && iKey>pCache->iMaxKey ){ pCache->iMaxKey = iKey; } if( createFlag==1 ) sqlite3EndBenignMalloc(); - pcache1LeaveMutex(); + pcache1LeaveMutex(pGroup); return (pPage ? PGHDR1_TO_PAGE(pPage) : 0); } /* @@ -672,37 +754,38 @@ ** Mark a page as unpinned (eligible for asynchronous recycling). */ static void pcache1Unpin(sqlite3_pcache *p, void *pPg, int reuseUnlikely){ PCache1 *pCache = (PCache1 *)p; PgHdr1 *pPage = PAGE_TO_PGHDR1(pCache, pPg); + PGroup *pGroup = pCache->pGroup; assert( pPage->pCache==pCache ); - pcache1EnterMutex(); + pcache1EnterMutex(pGroup); /* It is an error to call this function if the page is already - ** part of the global LRU list. + ** part of the PGroup LRU list. */ assert( pPage->pLruPrev==0 && pPage->pLruNext==0 ); - assert( pcache1.pLruHead!=pPage && pcache1.pLruTail!=pPage ); + assert( pGroup->pLruHead!=pPage && pGroup->pLruTail!=pPage ); - if( reuseUnlikely || pcache1.nCurrentPage>pcache1.nMaxPage ){ + if( reuseUnlikely || pGroup->nCurrentPage>pGroup->nMaxPage ){ pcache1RemoveFromHash(pPage); pcache1FreePage(pPage); }else{ - /* Add the page to the global LRU list. */ - if( pcache1.pLruHead ){ - pcache1.pLruHead->pLruPrev = pPage; - pPage->pLruNext = pcache1.pLruHead; - pcache1.pLruHead = pPage; + /* Add the page to the PGroup LRU list. */ + if( pGroup->pLruHead ){ + pGroup->pLruHead->pLruPrev = pPage; + pPage->pLruNext = pGroup->pLruHead; + pGroup->pLruHead = pPage; }else{ - pcache1.pLruTail = pPage; - pcache1.pLruHead = pPage; + pGroup->pLruTail = pPage; + pGroup->pLruHead = pPage; } pCache->nRecyclable++; } - pcache1LeaveMutex(); + pcache1LeaveMutex(pCache->pGroup); } /* ** Implementation of the sqlite3_pcache.xRekey method. */ @@ -717,11 +800,11 @@ PgHdr1 **pp; unsigned int h; assert( pPage->iKey==iOld ); assert( pPage->pCache==pCache ); - pcache1EnterMutex(); + pcache1EnterMutex(pCache->pGroup); h = iOld%pCache->nHash; pp = &pCache->apHash[h]; while( (*pp)!=pPage ){ pp = &(*pp)->pNext; @@ -734,11 +817,11 @@ pCache->apHash[h] = pPage; if( iNew>pCache->iMaxKey ){ pCache->iMaxKey = iNew; } - pcache1LeaveMutex(); + pcache1LeaveMutex(pCache->pGroup); } /* ** Implementation of the sqlite3_pcache.xTruncate method. ** @@ -746,32 +829,33 @@ ** or greater than parameter iLimit. Any pinned pages with a page number ** equal to or greater than iLimit are implicitly unpinned. */ static void pcache1Truncate(sqlite3_pcache *p, unsigned int iLimit){ PCache1 *pCache = (PCache1 *)p; - pcache1EnterMutex(); + pcache1EnterMutex(pCache->pGroup); if( iLimit<=pCache->iMaxKey ){ pcache1TruncateUnsafe(pCache, iLimit); pCache->iMaxKey = iLimit-1; } - pcache1LeaveMutex(); + pcache1LeaveMutex(pCache->pGroup); } /* ** Implementation of the sqlite3_pcache.xDestroy method. ** ** Destroy a cache allocated using pcache1Create(). */ static void pcache1Destroy(sqlite3_pcache *p){ PCache1 *pCache = (PCache1 *)p; + PGroup *pGroup = pCache->pGroup; assert( pCache->bPurgeable || (pCache->nMax==0 && pCache->nMin==0) ); - pcache1EnterMutex(); + pcache1EnterMutex(pGroup); pcache1TruncateUnsafe(pCache, 0); - pcache1.nMaxPage -= pCache->nMax; - pcache1.nMinPage -= pCache->nMin; - pcache1EnforceMaxPage(); - pcache1LeaveMutex(); + pGroup->nMaxPage -= pCache->nMax; + pGroup->nMinPage -= pCache->nMin; + pcache1EnforceMaxPage(pGroup); + pcache1LeaveMutex(pGroup); sqlite3_free(pCache->apHash); sqlite3_free(pCache); } /* @@ -806,20 +890,22 @@ ** been released, the function returns. The return value is the total number ** of bytes of memory released. */ int sqlite3PcacheReleaseMemory(int nReq){ int nFree = 0; + assert( sqlite3_mutex_notheld(pcache1.grp.mutex) ); + assert( sqlite3_mutex_notheld(pcache1.mutex) ); if( pcache1.pStart==0 ){ PgHdr1 *p; - pcache1EnterMutex(); - while( (nReq<0 || nFreepLruNext){ + for(p=pcache1.grp.pLruHead; p; p=p->pLruNext){ nRecyclable++; } - *pnCurrent = pcache1.nCurrentPage; - *pnMax = pcache1.nMaxPage; - *pnMin = pcache1.nMinPage; + *pnCurrent = pcache1.grp.nCurrentPage; + *pnMax = pcache1.grp.nMaxPage; + *pnMin = pcache1.grp.nMinPage; *pnRecyclable = nRecyclable; } #endif Index: src/sqlite.h.in ================================================================== --- src/sqlite.h.in +++ src/sqlite.h.in @@ -5264,11 +5264,12 @@ #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ -#define SQLITE_MUTEX_STATIC_LRU2 7 /* lru page list */ +#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ +#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ /* ** CAPI3REF: Retrieve the mutex for a database connection ** ** ^This interface returns a pointer the [sqlite3_mutex] object that Index: test/memsubsys1.test ================================================================== --- test/memsubsys1.test +++ test/memsubsys1.test @@ -94,13 +94,14 @@ sqlite3_config_pagecache [expr 1024+$xtra_size] 20 sqlite3_initialize reset_highwater_marks build_test_db memsubsys1-2 {PRAGMA page_size=1024} #show_memstats +set MEMORY_MANAGEMENT $sqlite_options(memorymanage) do_test memsubsys1-2.3 { set pg_ovfl [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_OVERFLOW 0] 2] -} [expr ($AUTOVACUUM+$TEMP_STORE>=2)*1024] +} [expr ($AUTOVACUUM+$TEMP_STORE+$MEMORY_MANAGEMENT>=3)*1024] do_test memsubsys1-2.4 { set pg_used [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 2] } 20 do_test memsubsys1-2.5 { set s_used [lindex [sqlite3_status SQLITE_STATUS_SCRATCH_USED 0] 2] Index: test/mutex1.test ================================================================== --- test/mutex1.test +++ test/mutex1.test @@ -118,11 +118,13 @@ catchsql { CREATE TABLE abc(a, b, c) } db eval { INSERT INTO abc VALUES(1, 2, 3); } } {} - + ifcapable !memorymanage { + regsub { static_lru} $mutexes {} mutexes + } do_test mutex1.2.$mode.3 { mutex_counters counters set res [list] foreach {key value} [array get counters] { Index: test/pcache.test ================================================================== --- test/pcache.test +++ test/pcache.test @@ -18,10 +18,18 @@ # Do not use a codec for tests in this file, as the database file is # manipulated directly using tcl scripts (using the [hexio_write] command). # do_not_use_codec + +# Only works with a mode-2 pcache where all pcaches share a single set +# of pages. +# +ifcapable {!memorymanage && threadsafe} { + finish_test + return +} # The pcache module limits the number of pages available to purgeable # caches to the sum of the 'cache_size' values for the set of open # caches. This block of tests, pcache-1.*, test that the library behaves # corrctly when it is forced to exceed this limit.