private static PgHdr pcache1Alloc(int nByte)
{
PgHdr p = null;
Debug.Assert(MutexEx.NotHeld(pcache1.grp.mutex));
StatusEx.sqlite3StatusSet(StatusEx.STATUS.PAGECACHE_SIZE, nByte);
if (nByte <= pcache1.szSlot)
{
MutexEx.Enter(pcache1.mutex);
p = pcache1.pFree._PgHdr;
if (p != null)
{
pcache1.pFree = pcache1.pFree.pNext;
pcache1.nFreeSlot--;
pcache1.bUnderPressure = pcache1.nFreeSlot < pcache1.nReserve;
Debug.Assert(pcache1.nFreeSlot >= 0);
StatusEx.sqlite3StatusAdd(StatusEx.STATUS.PAGECACHE_USED, 1);
}
MutexEx.Leave(pcache1.mutex);
}
if (p == null)
{
// Memory is not available in the SQLITE_CONFIG_PAGECACHE pool. Get it from sqlite3Malloc instead.
p = new PgHdr();
{
var sz = nByte;
MutexEx.Enter(pcache1.mutex);
StatusEx.sqlite3StatusAdd(StatusEx.STATUS.PAGECACHE_OVERFLOW, sz);
MutexEx.Leave(pcache1.mutex);
}
SysEx.sqlite3MemdebugSetType(p, SysEx.MEMTYPE.PCACHE);
}
return(p);
}
internal bool removeFromSharingList()
{
#if !SQLITE_OMIT_SHARED_CACHE
MutexEx pMaster;
BtShared list;
bool removed = false;
Debug.Assert(MutexEx.NotHeld(Mutex));
pMaster = MutexEx.Alloc(MUTEX.STATIC_MASTER);
MutexEx.Enter(pMaster);
nRef--;
if (nRef <= 0)
{
if (SysEx.getGLOBAL <BtShared>(Btree.s_sqlite3SharedCacheList) == this)
{
SysEx.setGLOBAL <BtShared>(Btree.s_sqlite3SharedCacheList, Next);
}
else
{
list = SysEx.getGLOBAL <BtShared>(Btree.s_sqlite3SharedCacheList);
while (Check.ALWAYS(list) != null && list.Next != this)
{
list = list.Next;
}
if (Check.ALWAYS(list) != null)
{
list.Next = Next;
}
}
if (MutexEx.SQLITE_THREADSAFE)
{
MutexEx.Free(Mutex);
}
removed = true;
}
MutexEx.Leave(pMaster);
return(removed);
#else
return(true);
#endif
}
