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The power-of-two first-fit memory allocator is now working. (CVS 4793)
FossilOrigin-Name: d134d29cea971eb01a0e0fd94341ab79e2d5b57a
This commit is contained in:
drh
602
src/mem5.c
602
src/mem5.c
@@ -20,7 +20,7 @@
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** This version of the memory allocation subsystem is used if
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** and only if SQLITE_POW2_MEMORY_SIZE is defined.
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**
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** $Id: mem5.c,v 1.1 2008/02/14 23:26:56 drh Exp $
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** $Id: mem5.c,v 1.2 2008/02/16 16:21:46 drh Exp $
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*/
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#include "sqliteInt.h"
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@@ -31,62 +31,60 @@
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#ifdef SQLITE_POW2_MEMORY_SIZE
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/*
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** Maximum size (in Mem3Blocks) of a "small" chunk.
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** Log2 of the minimum size of an allocation. For example, if
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** 4 then all allocations will be rounded up to at least 16 bytes.
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** If 5 then all allocations will be rounded up to at least 32 bytes.
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*/
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#define MX_SMALL 10
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#ifndef SQLITE_POW2_LOGMIN
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# define SQLITE_POW2_LOGMIN 6
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#endif
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#define POW2_MIN (1<<SQLITE_POW2_LOGMIN)
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/*
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** Number of freelist hash slots
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** Log2 of the maximum size of an allocation.
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*/
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#define N_HASH 61
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#ifndef SQLITE_POW2_LOGMAX
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# define SQLITE_POW2_LOGMAX 18
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#endif
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#define POW2_MAX (((unsigned int)1)<<SQLITE_POW2_LOGMAX)
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/*
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** A memory allocation (also called a "chunk") consists of two or
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** more blocks where each block is 8 bytes. The first 8 bytes are
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** a header that is not returned to the user.
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**
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** A chunk is two or more blocks that is either checked out or
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** free. The first block has format u.hdr. u.hdr.size4x is 4 times the
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** size of the allocation in blocks if the allocation is free.
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** The u.hdr.size4x&1 bit is true if the chunk is checked out and
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** false if the chunk is on the freelist. The u.hdr.size4x&2 bit
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** is true if the previous chunk is checked out and false if the
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** previous chunk is free. The u.hdr.prevSize field is the size of
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** the previous chunk in blocks if the previous chunk is on the
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** freelist. If the previous chunk is checked out, then
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** u.hdr.prevSize can be part of the data for that chunk and should
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** not be read or written.
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**
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** We often identify a chunk by its index in mem.aPool[]. When
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** this is done, the chunk index refers to the second block of
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** the chunk. In this way, the first chunk has an index of 1.
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** A chunk index of 0 means "no such chunk" and is the equivalent
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** of a NULL pointer.
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**
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** The second block of free chunks is of the form u.list. The
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** two fields form a double-linked list of chunks of related sizes.
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** Pointers to the head of the list are stored in mem.aiSmall[]
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** for smaller chunks and mem.aiHash[] for larger chunks.
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**
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** The second block of a chunk is user data if the chunk is checked
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** out. If a chunk is checked out, the user data may extend into
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** the u.hdr.prevSize value of the following chunk.
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** Number of distinct allocation sizes.
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*/
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typedef struct Mem3Block Mem3Block;
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struct Mem3Block {
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#define NSIZE (SQLITE_POW2_LOGMAX - SQLITE_POW2_LOGMIN + 1)
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/*
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** A minimum allocation is an instance of the following structure.
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** Larger allocations are an array of these structures where the
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** size of the array is a power of 2.
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*/
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typedef struct Mem5Block Mem5Block;
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struct Mem5Block {
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union {
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char aData[POW2_MIN];
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struct {
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u32 prevSize; /* Size of previous chunk in Mem3Block elements */
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u32 size4x; /* 4x the size of current chunk in Mem3Block elements */
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} hdr;
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struct {
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u32 next; /* Index in mem.aPool[] of next free chunk */
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u32 prev; /* Index in mem.aPool[] of previous free chunk */
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int next; /* Index in mem.aPool[] of next free chunk */
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int prev; /* Index in mem.aPool[] of previous free chunk */
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} list;
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} u;
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};
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/*
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** Number of blocks of memory available for allocation.
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*/
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#define NBLOCK (SQLITE_POW2_MEMORY_SIZE/POW2_MIN)
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/*
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** The size in blocks of an POW2_MAX allocation
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*/
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#define SZ_MAX (1<<(NSIZE-1))
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/*
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** Masks used for mem.aCtrl[] elements.
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*/
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#define CTRL_LOGSIZE 0x1f /* Log2 Size of this block relative to POW2_MIN */
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#define CTRL_FREE 0x20 /* True if not checked out */
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/*
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** All of the static variables used by this module are collected
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** into a single structure named "mem". This is to keep the
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@@ -103,112 +101,77 @@ static struct {
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** Mutex to control access to the memory allocation subsystem.
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*/
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sqlite3_mutex *mutex;
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/*
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** Performance statistics
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*/
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u64 nAlloc; /* Total number of calls to malloc */
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u64 totalAlloc; /* Total of all malloc calls - includes internal frag */
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u64 totalExcess; /* Total internal fragmentation */
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u32 currentOut; /* Current checkout, including internal fragmentation */
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u32 currentCount; /* Current number of distinct checkouts */
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u32 maxOut; /* Maximum instantaneous currentOut */
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u32 maxCount; /* Maximum instantaneous currentCount */
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u32 maxRequest; /* Largest allocation (exclusive of internal frag) */
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/*
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** The minimum amount of free space that we have seen.
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** Lists of free blocks of various sizes.
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*/
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u32 mnMaster;
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int aiFreelist[NSIZE];
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/*
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** iMaster is the index of the master chunk. Most new allocations
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** occur off of this chunk. szMaster is the size (in Mem3Blocks)
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** of the current master. iMaster is 0 if there is not master chunk.
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** The master chunk is not in either the aiHash[] or aiSmall[].
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** Space for tracking which blocks are checked out and the size
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** of each block. One byte per block.
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*/
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u32 iMaster;
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u32 szMaster;
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u64 totalAlloc;
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u64 totalExcess;
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int nAlloc;
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/*
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** Array of lists of free blocks according to the block size
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** for smaller chunks, or a hash on the block size for larger
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** chunks.
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*/
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u32 aiSmall[MX_SMALL-1]; /* For sizes 2 through MX_SMALL, inclusive */
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u32 aiHash[N_HASH]; /* For sizes MX_SMALL+1 and larger */
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u8 aCtrl[NBLOCK];
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/*
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** Memory available for allocation
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*/
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Mem3Block aPool[SQLITE_POW2_MEMORY_SIZE/sizeof(Mem3Block)+2];
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Mem5Block aPool[NBLOCK];
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} mem;
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/*
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** Unlink the chunk at mem.aPool[i] from list it is currently
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** on. *pRoot is the list that i is a member of.
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** on. It should be found on mem.aiFreelist[iLogsize].
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*/
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static void memsys3UnlinkFromList(u32 i, u32 *pRoot){
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u32 next = mem.aPool[i].u.list.next;
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u32 prev = mem.aPool[i].u.list.prev;
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static void memsys5Unlink(int i, int iLogsize){
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int next, prev;
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assert( i>=0 && i<NBLOCK );
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assert( iLogsize>=0 && iLogsize<NSIZE );
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assert( (mem.aCtrl[i] & CTRL_LOGSIZE)==iLogsize );
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assert( sqlite3_mutex_held(mem.mutex) );
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if( prev==0 ){
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*pRoot = next;
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next = mem.aPool[i].u.list.next;
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prev = mem.aPool[i].u.list.prev;
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if( prev<0 ){
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mem.aiFreelist[iLogsize] = next;
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}else{
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mem.aPool[prev].u.list.next = next;
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}
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if( next ){
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if( next>=0 ){
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mem.aPool[next].u.list.prev = prev;
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}
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mem.aPool[i].u.list.next = 0;
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mem.aPool[i].u.list.prev = 0;
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}
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/*
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** Unlink the chunk at index i from
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** whatever list is currently a member of.
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** Link the chunk at mem.aPool[i] so that is on the iLogsize
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** free list.
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*/
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static void memsys3Unlink(u32 i){
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u32 size, hash;
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static void memsys5Link(int i, int iLogsize){
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int x;
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assert( sqlite3_mutex_held(mem.mutex) );
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assert( (mem.aPool[i-1].u.hdr.size4x & 1)==0 );
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assert( i>=1 );
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size = mem.aPool[i-1].u.hdr.size4x/4;
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assert( size==mem.aPool[i+size-1].u.hdr.prevSize );
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assert( size>=2 );
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if( size <= MX_SMALL ){
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memsys3UnlinkFromList(i, &mem.aiSmall[size-2]);
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}else{
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hash = size % N_HASH;
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memsys3UnlinkFromList(i, &mem.aiHash[hash]);
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}
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}
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assert( i>=0 && i<NBLOCK );
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assert( iLogsize>=0 && iLogsize<NSIZE );
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assert( (mem.aCtrl[i] & CTRL_LOGSIZE)==iLogsize );
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/*
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** Link the chunk at mem.aPool[i] so that is on the list rooted
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** at *pRoot.
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*/
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static void memsys3LinkIntoList(u32 i, u32 *pRoot){
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assert( sqlite3_mutex_held(mem.mutex) );
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mem.aPool[i].u.list.next = *pRoot;
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mem.aPool[i].u.list.prev = 0;
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if( *pRoot ){
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mem.aPool[*pRoot].u.list.prev = i;
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}
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*pRoot = i;
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}
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/*
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** Link the chunk at index i into either the appropriate
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** small chunk list, or into the large chunk hash table.
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*/
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static void memsys3Link(u32 i){
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u32 size, hash;
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assert( sqlite3_mutex_held(mem.mutex) );
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assert( i>=1 );
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assert( (mem.aPool[i-1].u.hdr.size4x & 1)==0 );
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size = mem.aPool[i-1].u.hdr.size4x/4;
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assert( size==mem.aPool[i+size-1].u.hdr.prevSize );
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assert( size>=2 );
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if( size <= MX_SMALL ){
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memsys3LinkIntoList(i, &mem.aiSmall[size-2]);
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}else{
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hash = size % N_HASH;
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memsys3LinkIntoList(i, &mem.aiHash[hash]);
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mem.aPool[i].u.list.next = x = mem.aiFreelist[iLogsize];
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mem.aPool[i].u.list.prev = -1;
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if( x>=0 ){
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assert( x<NBLOCK );
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mem.aPool[x].u.list.prev = i;
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}
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mem.aiFreelist[iLogsize] = i;
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}
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/*
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@@ -217,28 +180,29 @@ static void memsys3Link(u32 i){
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** Also: Initialize the memory allocation subsystem the first time
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** this routine is called.
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*/
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static void memsys3Enter(void){
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static void memsys5Enter(void){
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if( mem.mutex==0 ){
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int i;
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assert( sizeof(Mem5Block)==POW2_MIN );
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assert( (SQLITE_POW2_MEMORY_SIZE % POW2_MAX)==0 );
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assert( SQLITE_POW2_MEMORY_SIZE>=POW2_MAX );
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mem.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM);
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mem.aPool[0].u.hdr.size4x = SQLITE_POW2_MEMORY_SIZE/2 + 2;
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mem.aPool[SQLITE_POW2_MEMORY_SIZE/8].u.hdr.prevSize = SQLITE_POW2_MEMORY_SIZE/8;
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mem.aPool[SQLITE_POW2_MEMORY_SIZE/8].u.hdr.size4x = 1;
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mem.iMaster = 1;
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mem.szMaster = SQLITE_POW2_MEMORY_SIZE/8;
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mem.mnMaster = mem.szMaster;
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sqlite3_mutex_enter(mem.mutex);
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for(i=0; i<NSIZE; i++) mem.aiFreelist[i] = -1;
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for(i=0; i<=NBLOCK-SZ_MAX; i += SZ_MAX){
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mem.aCtrl[i] = (NSIZE-1) | CTRL_FREE;
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memsys5Link(i, NSIZE-1);
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}
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}else{
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sqlite3_mutex_enter(mem.mutex);
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}
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sqlite3_mutex_enter(mem.mutex);
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}
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/*
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** Return the amount of memory currently checked out.
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*/
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sqlite3_int64 sqlite3_memory_used(void){
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sqlite3_int64 n;
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memsys3Enter();
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n = SQLITE_POW2_MEMORY_SIZE - mem.szMaster*8;
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sqlite3_mutex_leave(mem.mutex);
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return n;
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return mem.currentOut;
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}
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/*
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@@ -248,13 +212,11 @@ sqlite3_int64 sqlite3_memory_used(void){
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*/
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sqlite3_int64 sqlite3_memory_highwater(int resetFlag){
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sqlite3_int64 n;
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memsys3Enter();
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n = SQLITE_POW2_MEMORY_SIZE - mem.mnMaster*8;
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memsys5Enter();
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n = mem.maxOut;
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if( resetFlag ){
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mem.mnMaster = mem.szMaster;
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mem.maxOut = mem.currentOut;
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}
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printf("alloc-cnt=%d avg-size=%lld avg-excess=%lld\n",
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mem.nAlloc, mem.totalAlloc/mem.nAlloc, mem.totalExcess/mem.nAlloc);
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sqlite3_mutex_leave(mem.mutex);
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return n;
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}
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@@ -278,7 +240,7 @@ int sqlite3_memory_alarm(
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/*
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** Called when we are unable to satisfy an allocation of nBytes.
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*/
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static void memsys3OutOfMemory(int nByte){
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static void memsys5OutOfMemory(int nByte){
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if( !mem.alarmBusy ){
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mem.alarmBusy = 1;
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assert( sqlite3_mutex_held(mem.mutex) );
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@@ -297,232 +259,118 @@ static void memsys3OutOfMemory(int nByte){
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int sqlite3MallocSize(void *p){
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int iSize = 0;
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if( p ){
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Mem3Block *pBlock = (Mem3Block*)p;
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assert( (pBlock[-1].u.hdr.size4x&1)!=0 );
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iSize = (pBlock[-1].u.hdr.size4x&~3)*2 - 4;
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int i = ((Mem5Block*)p) - mem.aPool;
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assert( i>=0 && i<NBLOCK );
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iSize = 1 << ((mem.aCtrl[i]&CTRL_LOGSIZE) + SQLITE_POW2_LOGMIN);
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}
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return iSize;
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}
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/*
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** Chunk i is a free chunk that has been unlinked. Adjust its
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** size parameters for check-out and return a pointer to the
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** user portion of the chunk.
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** Find the first entry on the freelist iLogsize. Unlink that
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** entry and return its index.
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*/
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static void *memsys3Checkout(u32 i, int nBlock){
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u32 x;
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assert( sqlite3_mutex_held(mem.mutex) );
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assert( i>=1 );
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assert( mem.aPool[i-1].u.hdr.size4x/4==nBlock );
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assert( mem.aPool[i+nBlock-1].u.hdr.prevSize==nBlock );
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x = mem.aPool[i-1].u.hdr.size4x;
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mem.aPool[i-1].u.hdr.size4x = nBlock*4 | 1 | (x&2);
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mem.aPool[i+nBlock-1].u.hdr.prevSize = nBlock;
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mem.aPool[i+nBlock-1].u.hdr.size4x |= 2;
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return &mem.aPool[i];
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}
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static int memsys5UnlinkFirst(int iLogsize){
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int i;
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int iFirst;
|
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|
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/*
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** Carve a piece off of the end of the mem.iMaster free chunk.
|
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** Return a pointer to the new allocation. Or, if the master chunk
|
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** is not large enough, return 0.
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*/
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static void *memsys3FromMaster(int nBlock){
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assert( sqlite3_mutex_held(mem.mutex) );
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assert( mem.szMaster>=nBlock );
|
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if( nBlock>=mem.szMaster-1 ){
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/* Use the entire master */
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void *p = memsys3Checkout(mem.iMaster, mem.szMaster);
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mem.iMaster = 0;
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mem.szMaster = 0;
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mem.mnMaster = 0;
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return p;
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}else{
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/* Split the master block. Return the tail. */
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u32 newi, x;
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newi = mem.iMaster + mem.szMaster - nBlock;
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assert( newi > mem.iMaster+1 );
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mem.aPool[mem.iMaster+mem.szMaster-1].u.hdr.prevSize = nBlock;
|
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mem.aPool[mem.iMaster+mem.szMaster-1].u.hdr.size4x |= 2;
|
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mem.aPool[newi-1].u.hdr.size4x = nBlock*4 + 1;
|
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mem.szMaster -= nBlock;
|
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mem.aPool[newi-1].u.hdr.prevSize = mem.szMaster;
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x = mem.aPool[mem.iMaster-1].u.hdr.size4x & 2;
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mem.aPool[mem.iMaster-1].u.hdr.size4x = mem.szMaster*4 | x;
|
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if( mem.szMaster < mem.mnMaster ){
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mem.mnMaster = mem.szMaster;
|
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}
|
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return (void*)&mem.aPool[newi];
|
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}
|
||||
}
|
||||
|
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/*
|
||||
** *pRoot is the head of a list of free chunks of the same size
|
||||
** or same size hash. In other words, *pRoot is an entry in either
|
||||
** mem.aiSmall[] or mem.aiHash[].
|
||||
**
|
||||
** This routine examines all entries on the given list and tries
|
||||
** to coalesce each entries with adjacent free chunks.
|
||||
**
|
||||
** If it sees a chunk that is larger than mem.iMaster, it replaces
|
||||
** the current mem.iMaster with the new larger chunk. In order for
|
||||
** this mem.iMaster replacement to work, the master chunk must be
|
||||
** linked into the hash tables. That is not the normal state of
|
||||
** affairs, of course. The calling routine must link the master
|
||||
** chunk before invoking this routine, then must unlink the (possibly
|
||||
** changed) master chunk once this routine has finished.
|
||||
*/
|
||||
static void memsys3Merge(u32 *pRoot){
|
||||
u32 iNext, prev, size, i, x;
|
||||
|
||||
assert( sqlite3_mutex_held(mem.mutex) );
|
||||
for(i=*pRoot; i>0; i=iNext){
|
||||
iNext = mem.aPool[i].u.list.next;
|
||||
size = mem.aPool[i-1].u.hdr.size4x;
|
||||
assert( (size&1)==0 );
|
||||
if( (size&2)==0 ){
|
||||
memsys3UnlinkFromList(i, pRoot);
|
||||
assert( i > mem.aPool[i-1].u.hdr.prevSize );
|
||||
prev = i - mem.aPool[i-1].u.hdr.prevSize;
|
||||
if( prev==iNext ){
|
||||
iNext = mem.aPool[prev].u.list.next;
|
||||
}
|
||||
memsys3Unlink(prev);
|
||||
size = i + size/4 - prev;
|
||||
x = mem.aPool[prev-1].u.hdr.size4x & 2;
|
||||
mem.aPool[prev-1].u.hdr.size4x = size*4 | x;
|
||||
mem.aPool[prev+size-1].u.hdr.prevSize = size;
|
||||
memsys3Link(prev);
|
||||
i = prev;
|
||||
}else{
|
||||
size /= 4;
|
||||
}
|
||||
if( size>mem.szMaster ){
|
||||
mem.iMaster = i;
|
||||
mem.szMaster = size;
|
||||
}
|
||||
assert( iLogsize>=0 && iLogsize<NSIZE );
|
||||
i = iFirst = mem.aiFreelist[iLogsize];
|
||||
assert( iFirst>=0 );
|
||||
while( i>0 ){
|
||||
if( i<iFirst ) iFirst = i;
|
||||
i = mem.aPool[i].u.list.next;
|
||||
}
|
||||
memsys5Unlink(iFirst, iLogsize);
|
||||
return iFirst;
|
||||
}
|
||||
|
||||
/*
|
||||
** Return a block of memory of at least nBytes in size.
|
||||
** Return NULL if unable.
|
||||
*/
|
||||
static void *memsys3Malloc(int nByte){
|
||||
u32 i;
|
||||
int nBlock;
|
||||
int toFree;
|
||||
int x;
|
||||
static void *memsys5Malloc(int nByte){
|
||||
int i; /* Index of a mem.aPool[] slot */
|
||||
int iBin; /* Index into mem.aiFreelist[] */
|
||||
int iFullSz; /* Size of allocation rounded up to power of 2 */
|
||||
int iLogsize; /* Log2 of iFullSz/POW2_MIN */
|
||||
|
||||
assert( sqlite3_mutex_held(mem.mutex) );
|
||||
assert( sizeof(Mem3Block)==8 );
|
||||
for(x=256; x<nByte; x *= 2){}
|
||||
mem.nAlloc++;
|
||||
mem.totalAlloc += x;
|
||||
mem.totalExcess += x - nByte;
|
||||
nByte = x;
|
||||
nBlock = (nByte + 11)/8;
|
||||
assert( nBlock >= 2 );
|
||||
if( nByte>mem.maxRequest ) mem.maxRequest = nByte;
|
||||
if( nByte>POW2_MAX ) return 0;
|
||||
for(iFullSz=POW2_MIN, iLogsize=0; iFullSz<nByte; iFullSz *= 2, iLogsize++){}
|
||||
|
||||
/* STEP 1:
|
||||
** Look for an entry of the correct size in either the small
|
||||
** chunk table or in the large chunk hash table. This is
|
||||
** successful most of the time (about 9 times out of 10).
|
||||
*/
|
||||
if( nBlock <= MX_SMALL ){
|
||||
i = mem.aiSmall[nBlock-2];
|
||||
if( i>0 ){
|
||||
memsys3UnlinkFromList(i, &mem.aiSmall[nBlock-2]);
|
||||
return memsys3Checkout(i, nBlock);
|
||||
}
|
||||
}else{
|
||||
int hash = nBlock % N_HASH;
|
||||
for(i=mem.aiHash[hash]; i>0; i=mem.aPool[i].u.list.next){
|
||||
if( mem.aPool[i-1].u.hdr.size4x/4==nBlock ){
|
||||
memsys3UnlinkFromList(i, &mem.aiHash[hash]);
|
||||
return memsys3Checkout(i, nBlock);
|
||||
}
|
||||
}
|
||||
for(iBin=iLogsize; mem.aiFreelist[iBin]<0 && iBin<NSIZE; iBin++){}
|
||||
if( iBin>=NSIZE ) return 0;
|
||||
i = memsys5UnlinkFirst(iBin);
|
||||
while( iBin>iLogsize ){
|
||||
int newSize;
|
||||
|
||||
iBin--;
|
||||
newSize = 1 << iBin;
|
||||
mem.aCtrl[i+newSize] = CTRL_FREE | iBin;
|
||||
memsys5Link(i+newSize, iBin);
|
||||
}
|
||||
mem.aCtrl[i] = iLogsize;
|
||||
|
||||
/* STEP 2:
|
||||
** Try to satisfy the allocation by carving a piece off of the end
|
||||
** of the master chunk. This step usually works if step 1 fails.
|
||||
*/
|
||||
if( mem.szMaster>=nBlock ){
|
||||
return memsys3FromMaster(nBlock);
|
||||
}
|
||||
mem.nAlloc++;
|
||||
mem.totalAlloc += iFullSz;
|
||||
mem.totalExcess += iFullSz - nByte;
|
||||
mem.currentCount++;
|
||||
mem.currentOut += iFullSz;
|
||||
if( mem.maxCount<mem.currentCount ) mem.maxCount = mem.currentCount;
|
||||
if( mem.maxOut<mem.currentOut ) mem.maxOut = mem.currentOut;
|
||||
|
||||
|
||||
/* STEP 3:
|
||||
** Loop through the entire memory pool. Coalesce adjacent free
|
||||
** chunks. Recompute the master chunk as the largest free chunk.
|
||||
** Then try again to satisfy the allocation by carving a piece off
|
||||
** of the end of the master chunk. This step happens very
|
||||
** rarely (we hope!)
|
||||
*/
|
||||
for(toFree=nBlock*16; toFree<SQLITE_POW2_MEMORY_SIZE*2; toFree *= 2){
|
||||
memsys3OutOfMemory(toFree);
|
||||
if( mem.iMaster ){
|
||||
memsys3Link(mem.iMaster);
|
||||
mem.iMaster = 0;
|
||||
mem.szMaster = 0;
|
||||
}
|
||||
for(i=0; i<N_HASH; i++){
|
||||
memsys3Merge(&mem.aiHash[i]);
|
||||
}
|
||||
for(i=0; i<MX_SMALL-1; i++){
|
||||
memsys3Merge(&mem.aiSmall[i]);
|
||||
}
|
||||
if( mem.szMaster ){
|
||||
memsys3Unlink(mem.iMaster);
|
||||
if( mem.szMaster>=nBlock ){
|
||||
return memsys3FromMaster(nBlock);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/* If none of the above worked, then we fail. */
|
||||
return 0;
|
||||
return (void*)&mem.aPool[i];
|
||||
}
|
||||
|
||||
/*
|
||||
** Free an outstanding memory allocation.
|
||||
*/
|
||||
void memsys3Free(void *pOld){
|
||||
Mem3Block *p = (Mem3Block*)pOld;
|
||||
void memsys5Free(void *pOld){
|
||||
u32 size, iLogsize;
|
||||
int i;
|
||||
u32 size, x;
|
||||
assert( sqlite3_mutex_held(mem.mutex) );
|
||||
assert( p>mem.aPool && p<&mem.aPool[SQLITE_POW2_MEMORY_SIZE/8] );
|
||||
i = p - mem.aPool;
|
||||
assert( (mem.aPool[i-1].u.hdr.size4x&1)==1 );
|
||||
size = mem.aPool[i-1].u.hdr.size4x/4;
|
||||
assert( i+size<=SQLITE_POW2_MEMORY_SIZE/8+1 );
|
||||
mem.aPool[i-1].u.hdr.size4x &= ~1;
|
||||
mem.aPool[i+size-1].u.hdr.prevSize = size;
|
||||
mem.aPool[i+size-1].u.hdr.size4x &= ~2;
|
||||
memsys3Link(i);
|
||||
|
||||
/* Try to expand the master using the newly freed chunk */
|
||||
if( mem.iMaster ){
|
||||
while( (mem.aPool[mem.iMaster-1].u.hdr.size4x&2)==0 ){
|
||||
size = mem.aPool[mem.iMaster-1].u.hdr.prevSize;
|
||||
mem.iMaster -= size;
|
||||
mem.szMaster += size;
|
||||
memsys3Unlink(mem.iMaster);
|
||||
x = mem.aPool[mem.iMaster-1].u.hdr.size4x & 2;
|
||||
mem.aPool[mem.iMaster-1].u.hdr.size4x = mem.szMaster*4 | x;
|
||||
mem.aPool[mem.iMaster+mem.szMaster-1].u.hdr.prevSize = mem.szMaster;
|
||||
i = ((Mem5Block*)pOld) - mem.aPool;
|
||||
assert( sqlite3_mutex_held(mem.mutex) );
|
||||
assert( i>=0 && i<NBLOCK );
|
||||
assert( (mem.aCtrl[i] & CTRL_FREE)==0 );
|
||||
iLogsize = mem.aCtrl[i] & CTRL_LOGSIZE;
|
||||
size = 1<<iLogsize;
|
||||
assert( i+size-1<NBLOCK );
|
||||
mem.aCtrl[i] |= CTRL_FREE;
|
||||
mem.aCtrl[i+size-1] |= CTRL_FREE;
|
||||
assert( mem.currentCount>0 );
|
||||
assert( mem.currentOut>=0 );
|
||||
mem.currentCount--;
|
||||
mem.currentOut -= size*POW2_MIN;
|
||||
assert( mem.currentOut>0 || mem.currentCount==0 );
|
||||
assert( mem.currentCount>0 || mem.currentOut==0 );
|
||||
|
||||
mem.aCtrl[i] = CTRL_FREE | iLogsize;
|
||||
while( iLogsize<NSIZE-1 ){
|
||||
int iBuddy;
|
||||
|
||||
if( (i>>iLogsize) & 1 ){
|
||||
iBuddy = i - size;
|
||||
}else{
|
||||
iBuddy = i + size;
|
||||
}
|
||||
x = mem.aPool[mem.iMaster-1].u.hdr.size4x & 2;
|
||||
while( (mem.aPool[mem.iMaster+mem.szMaster-1].u.hdr.size4x&1)==0 ){
|
||||
memsys3Unlink(mem.iMaster+mem.szMaster);
|
||||
mem.szMaster += mem.aPool[mem.iMaster+mem.szMaster-1].u.hdr.size4x/4;
|
||||
mem.aPool[mem.iMaster-1].u.hdr.size4x = mem.szMaster*4 | x;
|
||||
mem.aPool[mem.iMaster+mem.szMaster-1].u.hdr.prevSize = mem.szMaster;
|
||||
assert( iBuddy>=0 && iBuddy<NBLOCK );
|
||||
if( mem.aCtrl[iBuddy]!=(CTRL_FREE | iLogsize) ) break;
|
||||
memsys5Unlink(iBuddy, iLogsize);
|
||||
iLogsize++;
|
||||
if( iBuddy<i ){
|
||||
mem.aCtrl[iBuddy] = CTRL_FREE | iLogsize;
|
||||
mem.aCtrl[i] = 0;
|
||||
i = iBuddy;
|
||||
}else{
|
||||
mem.aCtrl[i] = CTRL_FREE | iLogsize;
|
||||
mem.aCtrl[iBuddy] = 0;
|
||||
}
|
||||
size *= 2;
|
||||
}
|
||||
memsys5Link(i, iLogsize);
|
||||
}
|
||||
|
||||
/*
|
||||
@@ -531,8 +379,8 @@ void memsys3Free(void *pOld){
|
||||
void *sqlite3_malloc(int nBytes){
|
||||
sqlite3_int64 *p = 0;
|
||||
if( nBytes>0 ){
|
||||
memsys3Enter();
|
||||
p = memsys3Malloc(nBytes);
|
||||
memsys5Enter();
|
||||
p = memsys5Malloc(nBytes);
|
||||
sqlite3_mutex_leave(mem.mutex);
|
||||
}
|
||||
return (void*)p;
|
||||
@@ -547,7 +395,7 @@ void sqlite3_free(void *pPrior){
|
||||
}
|
||||
assert( mem.mutex!=0 );
|
||||
sqlite3_mutex_enter(mem.mutex);
|
||||
memsys3Free(pPrior);
|
||||
memsys5Free(pPrior);
|
||||
sqlite3_mutex_leave(mem.mutex);
|
||||
}
|
||||
|
||||
@@ -566,18 +414,14 @@ void *sqlite3_realloc(void *pPrior, int nBytes){
|
||||
}
|
||||
assert( mem.mutex!=0 );
|
||||
nOld = sqlite3MallocSize(pPrior);
|
||||
if( nBytes<=nOld && nBytes>=nOld-128 ){
|
||||
if( nBytes<=nOld ){
|
||||
return pPrior;
|
||||
}
|
||||
sqlite3_mutex_enter(mem.mutex);
|
||||
p = memsys3Malloc(nBytes);
|
||||
p = memsys5Malloc(nBytes);
|
||||
if( p ){
|
||||
if( nOld<nBytes ){
|
||||
memcpy(p, pPrior, nOld);
|
||||
}else{
|
||||
memcpy(p, pPrior, nBytes);
|
||||
}
|
||||
memsys3Free(pPrior);
|
||||
memcpy(p, pPrior, nOld);
|
||||
memsys5Free(pPrior);
|
||||
}
|
||||
sqlite3_mutex_leave(mem.mutex);
|
||||
return p;
|
||||
@@ -590,8 +434,8 @@ void *sqlite3_realloc(void *pPrior, int nBytes){
|
||||
void sqlite3_memdebug_dump(const char *zFilename){
|
||||
#ifdef SQLITE_DEBUG
|
||||
FILE *out;
|
||||
int i, j;
|
||||
u32 size;
|
||||
int i, j, n;
|
||||
|
||||
if( zFilename==0 || zFilename[0]==0 ){
|
||||
out = stdout;
|
||||
}else{
|
||||
@@ -602,53 +446,19 @@ void sqlite3_memdebug_dump(const char *zFilename){
|
||||
return;
|
||||
}
|
||||
}
|
||||
memsys3Enter();
|
||||
fprintf(out, "CHUNKS:\n");
|
||||
for(i=1; i<=SQLITE_POW2_MEMORY_SIZE/8; i+=size/4){
|
||||
size = mem.aPool[i-1].u.hdr.size4x;
|
||||
if( size/4<=1 ){
|
||||
fprintf(out, "%p size error\n", &mem.aPool[i]);
|
||||
assert( 0 );
|
||||
break;
|
||||
}
|
||||
if( (size&1)==0 && mem.aPool[i+size/4-1].u.hdr.prevSize!=size/4 ){
|
||||
fprintf(out, "%p tail size does not match\n", &mem.aPool[i]);
|
||||
assert( 0 );
|
||||
break;
|
||||
}
|
||||
if( ((mem.aPool[i+size/4-1].u.hdr.size4x&2)>>1)!=(size&1) ){
|
||||
fprintf(out, "%p tail checkout bit is incorrect\n", &mem.aPool[i]);
|
||||
assert( 0 );
|
||||
break;
|
||||
}
|
||||
if( size&1 ){
|
||||
fprintf(out, "%p %6d bytes checked out\n", &mem.aPool[i], (size/4)*8-8);
|
||||
}else{
|
||||
fprintf(out, "%p %6d bytes free%s\n", &mem.aPool[i], (size/4)*8-8,
|
||||
i==mem.iMaster ? " **master**" : "");
|
||||
}
|
||||
memsys5Enter();
|
||||
for(i=0; i<NSIZE; i++){
|
||||
for(n=0, j=mem.aiFreelist[i]; j>=0; j = mem.aPool[j].u.list.next, n++){}
|
||||
fprintf(out, "freelist items of size %d: %d\n", POW2_MIN << i, n);
|
||||
}
|
||||
for(i=0; i<MX_SMALL-1; i++){
|
||||
if( mem.aiSmall[i]==0 ) continue;
|
||||
fprintf(out, "small(%2d):", i);
|
||||
for(j = mem.aiSmall[i]; j>0; j=mem.aPool[j].u.list.next){
|
||||
fprintf(out, " %p(%d)", &mem.aPool[j],
|
||||
(mem.aPool[j-1].u.hdr.size4x/4)*8-8);
|
||||
}
|
||||
fprintf(out, "\n");
|
||||
}
|
||||
for(i=0; i<N_HASH; i++){
|
||||
if( mem.aiHash[i]==0 ) continue;
|
||||
fprintf(out, "hash(%2d):", i);
|
||||
for(j = mem.aiHash[i]; j>0; j=mem.aPool[j].u.list.next){
|
||||
fprintf(out, " %p(%d)", &mem.aPool[j],
|
||||
(mem.aPool[j-1].u.hdr.size4x/4)*8-8);
|
||||
}
|
||||
fprintf(out, "\n");
|
||||
}
|
||||
fprintf(out, "master=%d\n", mem.iMaster);
|
||||
fprintf(out, "nowUsed=%d\n", SQLITE_POW2_MEMORY_SIZE - mem.szMaster*8);
|
||||
fprintf(out, "mxUsed=%d\n", SQLITE_POW2_MEMORY_SIZE - mem.mnMaster*8);
|
||||
fprintf(out, "mem.nAlloc = %llu\n", mem.nAlloc);
|
||||
fprintf(out, "mem.totalAlloc = %llu\n", mem.totalAlloc);
|
||||
fprintf(out, "mem.totalExcess = %llu\n", mem.totalExcess);
|
||||
fprintf(out, "mem.currentOut = %u\n", mem.currentOut);
|
||||
fprintf(out, "mem.currentCount = %u\n", mem.currentCount);
|
||||
fprintf(out, "mem.maxOut = %u\n", mem.maxOut);
|
||||
fprintf(out, "mem.maxCount = %u\n", mem.maxCount);
|
||||
fprintf(out, "mem.maxRequest = %u\n", mem.maxRequest);
|
||||
sqlite3_mutex_leave(mem.mutex);
|
||||
if( out==stdout ){
|
||||
fflush(stdout);
|
||||
|
||||
Reference in New Issue
Block a user