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
/* 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 */
** 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;
/*
#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 **************/
** 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 ){
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;
** 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<pcache1.nReserve;
+ assert( 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);
** 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 && p<pcache1.pEnd ){
PgFreeslot *pSlot;
+ sqlite3_mutex_enter(pcache1.mutex);
sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_USED, -1);
pSlot = (PgFreeslot*)p;
pSlot->pNext = pcache1.pFree;
pcache1.pFree = pSlot;
pcache1.nFreeSlot++;
+ pcache1.bUnderPressure = pcache1.nFreeSlot<pcache1.nReserve;
assert( pcache1.nFreeSlot<=pcache1.nSlot );
+ sqlite3_mutex_leave(pcache1.mutex);
}else{
int iSize;
assert( sqlite3MemdebugHasType(p, MEMTYPE_PCACHE) );
** Return the size of a pcache allocation
*/
static int pcache1MemSize(void *p){
- assert( sqlite3_mutex_held(pcache1.mutex) );
if( p>=pcache1.pStart && p<pcache1.pEnd ){
return pcache1.szSlot;
}else{
if( pPg ){
p = PAGE_TO_PGHDR1(pCache, pPg);
if( pCache->bPurgeable ){
- pcache1.nCurrentPage++;
+ pCache->pGroup->nCurrentPage++;
}
}else{
p = 0;
*/
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));
}
** 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();
}
** the heap even further.
*/
static int pcache1UnderMemoryPressure(PCache1 *pCache){
- assert( sqlite3_mutex_held(pcache1.mutex) );
if( pcache1.nSlot && pCache->szPage<=pcache1.szSlot ){
- return pcache1.nFreeSlot<pcache1.nReserve;
+ return pcache1.bUnderPressure;
}else{
return sqlite3HeapNearlyFull();
}
** This function is used to resize the hash table used by the cache passed
** as the first argument.
**
-** The global mutex must be held when this function is called.
+** The PCache mutex must be held when this function is called.
*/
static int pcache1ResizeHash(PCache1 *p){
PgHdr1 **apNew;
unsigned int nNew;
unsigned int i;
- assert( sqlite3_mutex_held(pcache1.mutex) );
+ assert( sqlite3_mutex_held(p->pGroup->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; i<p->nHash; i++){
/*
** 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;
** 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;
}
/*
-** 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);
** 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; h<pCache->nHash; h++){
PgHdr1 **pp = &pCache->apHash[h];
PgHdr1 *pPage;
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_MEM2);
}
pcache1.isInit = 1;
return SQLITE_OK;
** 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;
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);
}
}
*/
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;
}
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. */
/* 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)
)){
}
/* 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);
}
}
** attempt to allocate a new one.
*/
if( !pPage ){
+ pcache1LeaveMutex(pGroup);
pPage = pcache1AllocPage(pCache);
+ pcache1EnterMutex(pGroup);
}
if( pPage ){
pCache->iMaxKey = iKey;
}
if( createFlag==1 ) sqlite3EndBenignMalloc();
- pcache1LeaveMutex();
+ pcache1LeaveMutex(pGroup);
return (pPage ? PGHDR1_TO_PAGE(pPage) : 0);
}
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);
}
/*
assert( pPage->iKey==iOld );
assert( pPage->pCache==pCache );
- pcache1EnterMutex();
+ pcache1EnterMutex(pCache->pGroup);
h = iOld%pCache->nHash;
pp = &pCache->apHash[h];
pCache->iMaxKey = iNew;
}
- pcache1LeaveMutex();
+ pcache1LeaveMutex(pCache->pGroup);
}
/*
*/
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);
}
/*
*/
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);
}
*/
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 || nFree<nReq) && ((p=pcache1.pLruTail)!=0) ){
+ pcache1EnterMutex(&pcache1.grp);
+ while( (nReq<0 || nFree<nReq) && ((p=pcache1.grp.pLruTail)!=0) ){
nFree += pcache1MemSize(PGHDR1_TO_PAGE(p));
pcache1PinPage(p);
pcache1RemoveFromHash(p);
pcache1FreePage(p);
}
- pcache1LeaveMutex();
+ pcache1LeaveMutex(&pcache1.grp);
}
return nFree;
}
){
PgHdr1 *p;
int nRecyclable = 0;
- for(p=pcache1.pLruHead; p; p=p->pLruNext){
+ 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
projects / thirdparty / sqlite.git / commitdiff
