**
** This version of the memory allocation subsystem omits all
** use of malloc(). All dynamically allocatable memory is
-** contained in a static array, mem.aPool[]. The size of this
+** contained in a static array, mem3.aPool[]. The size of this
** fixed memory pool is SQLITE_MEMORY_SIZE bytes.
**
** This version of the memory allocation subsystem is used if
** and only if SQLITE_MEMORY_SIZE is defined.
**
-** $Id: mem3.c,v 1.14 2008/06/18 17:09:10 danielk1977 Exp $
+** $Id: mem3.c,v 1.15 2008/06/24 19:02:55 danielk1977 Exp $
*/
#include "sqliteInt.h"
/*
-** This version of the memory allocator is used only when
-** SQLITE_MEMORY_SIZE is defined.
+** This version of the memory allocator is only built into the library
+** SQLITE_ENABLE_MEMPOOL is defined. Defining this symbol does not
+** mean that the library will use a memory-pool by default, just that
+** it is available. The mempool allocator is activated by calling
+** sqlite3_config().
*/
-#ifdef SQLITE_MEMORY_SIZE
+#ifdef SQLITE_ENABLE_MEMPOOL
/*
** Maximum size (in Mem3Blocks) of a "small" chunk.
** u.hdr.prevSize can be part of the data for that chunk and should
** not be read or written.
**
-** We often identify a chunk by its index in mem.aPool[]. When
+** We often identify a chunk by its index in mem3.aPool[]. When
** this is done, the chunk index refers to the second block of
** the chunk. In this way, the first chunk has an index of 1.
** A chunk index of 0 means "no such chunk" and is the equivalent
**
** The second block of free chunks is of the form u.list. The
** two fields form a double-linked list of chunks of related sizes.
-** Pointers to the head of the list are stored in mem.aiSmall[]
-** for smaller chunks and mem.aiHash[] for larger chunks.
+** Pointers to the head of the list are stored in mem3.aiSmall[]
+** for smaller chunks and mem3.aiHash[] for larger chunks.
**
** The second block of a chunk is user data if the chunk is checked
** out. If a chunk is checked out, the user data may extend into
u32 size4x; /* 4x the size of current chunk in Mem3Block elements */
} hdr;
struct {
- u32 next; /* Index in mem.aPool[] of next free chunk */
- u32 prev; /* Index in mem.aPool[] of previous free chunk */
+ u32 next; /* Index in mem3.aPool[] of next free chunk */
+ u32 prev; /* Index in mem3.aPool[] of previous free chunk */
} list;
} u;
};
/*
** All of the static variables used by this module are collected
-** into a single structure named "mem". This is to keep the
+** into a single structure named "mem3". This is to keep the
** static variables organized and to reduce namespace pollution
** when this module is combined with other in the amalgamation.
*/
u32 aiHash[N_HASH]; /* For sizes MX_SMALL+1 and larger */
/*
- ** Memory available for allocation
+ ** Memory available for allocation. nPool is the size of the array
+ ** (in Mem3Blocks) pointed to by aPool less 2.
*/
- Mem3Block aPool[SQLITE_MEMORY_SIZE/sizeof(Mem3Block)+2];
-} mem;
+ u32 nPool;
+ Mem3Block *aPool;
+ /* Mem3Block aPool[SQLITE_MEMORY_SIZE/sizeof(Mem3Block)+2]; */
+} mem3;
/*
-** Unlink the chunk at mem.aPool[i] from list it is currently
+** Unlink the chunk at mem3.aPool[i] from list it is currently
** on. *pRoot is the list that i is a member of.
*/
static void memsys3UnlinkFromList(u32 i, u32 *pRoot){
- u32 next = mem.aPool[i].u.list.next;
- u32 prev = mem.aPool[i].u.list.prev;
- assert( sqlite3_mutex_held(mem.mutex) );
+ u32 next = mem3.aPool[i].u.list.next;
+ u32 prev = mem3.aPool[i].u.list.prev;
+ assert( sqlite3_mutex_held(mem3.mutex) );
if( prev==0 ){
*pRoot = next;
}else{
- mem.aPool[prev].u.list.next = next;
+ mem3.aPool[prev].u.list.next = next;
}
if( next ){
- mem.aPool[next].u.list.prev = prev;
+ mem3.aPool[next].u.list.prev = prev;
}
- mem.aPool[i].u.list.next = 0;
- mem.aPool[i].u.list.prev = 0;
+ mem3.aPool[i].u.list.next = 0;
+ mem3.aPool[i].u.list.prev = 0;
}
/*
*/
static void memsys3Unlink(u32 i){
u32 size, hash;
- assert( sqlite3_mutex_held(mem.mutex) );
- assert( (mem.aPool[i-1].u.hdr.size4x & 1)==0 );
+ assert( sqlite3_mutex_held(mem3.mutex) );
+ assert( (mem3.aPool[i-1].u.hdr.size4x & 1)==0 );
assert( i>=1 );
- size = mem.aPool[i-1].u.hdr.size4x/4;
- assert( size==mem.aPool[i+size-1].u.hdr.prevSize );
+ size = mem3.aPool[i-1].u.hdr.size4x/4;
+ assert( size==mem3.aPool[i+size-1].u.hdr.prevSize );
assert( size>=2 );
if( size <= MX_SMALL ){
- memsys3UnlinkFromList(i, &mem.aiSmall[size-2]);
+ memsys3UnlinkFromList(i, &mem3.aiSmall[size-2]);
}else{
hash = size % N_HASH;
- memsys3UnlinkFromList(i, &mem.aiHash[hash]);
+ memsys3UnlinkFromList(i, &mem3.aiHash[hash]);
}
}
/*
-** Link the chunk at mem.aPool[i] so that is on the list rooted
+** Link the chunk at mem3.aPool[i] so that is on the list rooted
** at *pRoot.
*/
static void memsys3LinkIntoList(u32 i, u32 *pRoot){
- assert( sqlite3_mutex_held(mem.mutex) );
- mem.aPool[i].u.list.next = *pRoot;
- mem.aPool[i].u.list.prev = 0;
+ assert( sqlite3_mutex_held(mem3.mutex) );
+ mem3.aPool[i].u.list.next = *pRoot;
+ mem3.aPool[i].u.list.prev = 0;
if( *pRoot ){
- mem.aPool[*pRoot].u.list.prev = i;
+ mem3.aPool[*pRoot].u.list.prev = i;
}
*pRoot = i;
}
*/
static void memsys3Link(u32 i){
u32 size, hash;
- assert( sqlite3_mutex_held(mem.mutex) );
+ assert( sqlite3_mutex_held(mem3.mutex) );
assert( i>=1 );
- assert( (mem.aPool[i-1].u.hdr.size4x & 1)==0 );
- size = mem.aPool[i-1].u.hdr.size4x/4;
- assert( size==mem.aPool[i+size-1].u.hdr.prevSize );
+ assert( (mem3.aPool[i-1].u.hdr.size4x & 1)==0 );
+ size = mem3.aPool[i-1].u.hdr.size4x/4;
+ assert( size==mem3.aPool[i+size-1].u.hdr.prevSize );
assert( size>=2 );
if( size <= MX_SMALL ){
- memsys3LinkIntoList(i, &mem.aiSmall[size-2]);
+ memsys3LinkIntoList(i, &mem3.aiSmall[size-2]);
}else{
hash = size % N_HASH;
- memsys3LinkIntoList(i, &mem.aiHash[hash]);
+ memsys3LinkIntoList(i, &mem3.aiHash[hash]);
}
}
/*
-** Enter the mutex mem.mutex. Allocate it if it is not already allocated.
+** Enter the mutex mem3.mutex. Allocate it if it is not already allocated.
**
** Also: Initialize the memory allocation subsystem the first time
** this routine is called.
*/
static void memsys3Enter(void){
- if( mem.mutex==0 ){
- mem.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
- mem.aPool[0].u.hdr.size4x = SQLITE_MEMORY_SIZE/2 + 2;
- mem.aPool[SQLITE_MEMORY_SIZE/8].u.hdr.prevSize = SQLITE_MEMORY_SIZE/8;
- mem.aPool[SQLITE_MEMORY_SIZE/8].u.hdr.size4x = 1;
- mem.iMaster = 1;
- mem.szMaster = SQLITE_MEMORY_SIZE/8;
- mem.mnMaster = mem.szMaster;
+#if 0
+ if( mem3.mutex==0 ){
+ mem3.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
}
- sqlite3_mutex_enter(mem.mutex);
-}
-
-/*
-** Return the amount of memory currently checked out.
-*/
-sqlite3_int64 sqlite3_memory_used(void){
- sqlite3_int64 n;
- memsys3Enter();
- n = SQLITE_MEMORY_SIZE - mem.szMaster*8;
- sqlite3_mutex_leave(mem.mutex);
- return n;
+ sqlite3_mutex_enter(mem3.mutex);
+#endif
}
-
-/*
-** Return the maximum amount of memory that has ever been
-** checked out since either the beginning of this process
-** or since the most recent reset.
-*/
-sqlite3_int64 sqlite3_memory_highwater(int resetFlag){
- sqlite3_int64 n;
- memsys3Enter();
- n = SQLITE_MEMORY_SIZE - mem.mnMaster*8;
- if( resetFlag ){
- mem.mnMaster = mem.szMaster;
- }
- sqlite3_mutex_leave(mem.mutex);
- return n;
-}
-
-/*
-** Change the alarm callback.
-**
-** This is a no-op for the static memory allocator. The purpose
-** of the memory alarm is to support sqlite3_soft_heap_limit().
-** But with this memory allocator, the soft_heap_limit is really
-** a hard limit that is fixed at SQLITE_MEMORY_SIZE.
-*/
-int sqlite3_memory_alarm(
- void(*xCallback)(void *pArg, sqlite3_int64 used,int N),
- void *pArg,
- sqlite3_int64 iThreshold
-){
- return SQLITE_OK;
+static void memsys3Leave(void){
}
/*
** Called when we are unable to satisfy an allocation of nBytes.
*/
static void memsys3OutOfMemory(int nByte){
- if( !mem.alarmBusy ){
- mem.alarmBusy = 1;
- assert( sqlite3_mutex_held(mem.mutex) );
- sqlite3_mutex_leave(mem.mutex);
+ if( !mem3.alarmBusy ){
+ mem3.alarmBusy = 1;
+ assert( sqlite3_mutex_held(mem3.mutex) );
+ sqlite3_mutex_leave(mem3.mutex);
sqlite3_release_memory(nByte);
- sqlite3_mutex_enter(mem.mutex);
- mem.alarmBusy = 0;
+ sqlite3_mutex_enter(mem3.mutex);
+ mem3.alarmBusy = 0;
}
}
-/*
-** Return the size of an outstanding allocation, in bytes. The
-** size returned omits the 8-byte header overhead. This only
-** works for chunks that are currently checked out.
-*/
-int sqlite3MallocSize(void *p){
- int iSize = 0;
- if( p ){
- Mem3Block *pBlock = (Mem3Block*)p;
- assert( (pBlock[-1].u.hdr.size4x&1)!=0 );
- iSize = (pBlock[-1].u.hdr.size4x&~3)*2 - 4;
- }
- return iSize;
-}
-
-/*
-** Initialize the memmory allocation subsystem.
-*/
-int sqlite3MallocInit(void){
- return SQLITE_OK;
-}
/*
** Chunk i is a free chunk that has been unlinked. Adjust its
*/
static void *memsys3Checkout(u32 i, int nBlock){
u32 x;
- assert( sqlite3_mutex_held(mem.mutex) );
+ assert( sqlite3_mutex_held(mem3.mutex) );
assert( i>=1 );
- assert( mem.aPool[i-1].u.hdr.size4x/4==nBlock );
- assert( mem.aPool[i+nBlock-1].u.hdr.prevSize==nBlock );
- x = mem.aPool[i-1].u.hdr.size4x;
- mem.aPool[i-1].u.hdr.size4x = nBlock*4 | 1 | (x&2);
- mem.aPool[i+nBlock-1].u.hdr.prevSize = nBlock;
- mem.aPool[i+nBlock-1].u.hdr.size4x |= 2;
- return &mem.aPool[i];
+ assert( mem3.aPool[i-1].u.hdr.size4x/4==nBlock );
+ assert( mem3.aPool[i+nBlock-1].u.hdr.prevSize==nBlock );
+ x = mem3.aPool[i-1].u.hdr.size4x;
+ mem3.aPool[i-1].u.hdr.size4x = nBlock*4 | 1 | (x&2);
+ mem3.aPool[i+nBlock-1].u.hdr.prevSize = nBlock;
+ mem3.aPool[i+nBlock-1].u.hdr.size4x |= 2;
+ return &mem3.aPool[i];
}
/*
-** Carve a piece off of the end of the mem.iMaster free chunk.
+** Carve a piece off of the end of the mem3.iMaster free chunk.
** Return a pointer to the new allocation. Or, if the master chunk
** is not large enough, return 0.
*/
static void *memsys3FromMaster(int nBlock){
- assert( sqlite3_mutex_held(mem.mutex) );
- assert( mem.szMaster>=nBlock );
- if( nBlock>=mem.szMaster-1 ){
+ assert( sqlite3_mutex_held(mem3.mutex) );
+ assert( mem3.szMaster>=nBlock );
+ if( nBlock>=mem3.szMaster-1 ){
/* Use the entire master */
- void *p = memsys3Checkout(mem.iMaster, mem.szMaster);
- mem.iMaster = 0;
- mem.szMaster = 0;
- mem.mnMaster = 0;
+ void *p = memsys3Checkout(mem3.iMaster, mem3.szMaster);
+ mem3.iMaster = 0;
+ mem3.szMaster = 0;
+ mem3.mnMaster = 0;
return p;
}else{
/* Split the master block. Return the tail. */
u32 newi, x;
- newi = mem.iMaster + mem.szMaster - nBlock;
- assert( newi > mem.iMaster+1 );
- mem.aPool[mem.iMaster+mem.szMaster-1].u.hdr.prevSize = nBlock;
- mem.aPool[mem.iMaster+mem.szMaster-1].u.hdr.size4x |= 2;
- mem.aPool[newi-1].u.hdr.size4x = nBlock*4 + 1;
- mem.szMaster -= nBlock;
- mem.aPool[newi-1].u.hdr.prevSize = mem.szMaster;
- x = mem.aPool[mem.iMaster-1].u.hdr.size4x & 2;
- mem.aPool[mem.iMaster-1].u.hdr.size4x = mem.szMaster*4 | x;
- if( mem.szMaster < mem.mnMaster ){
- mem.mnMaster = mem.szMaster;
+ newi = mem3.iMaster + mem3.szMaster - nBlock;
+ assert( newi > mem3.iMaster+1 );
+ mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.prevSize = nBlock;
+ mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.size4x |= 2;
+ mem3.aPool[newi-1].u.hdr.size4x = nBlock*4 + 1;
+ mem3.szMaster -= nBlock;
+ mem3.aPool[newi-1].u.hdr.prevSize = mem3.szMaster;
+ x = mem3.aPool[mem3.iMaster-1].u.hdr.size4x & 2;
+ mem3.aPool[mem3.iMaster-1].u.hdr.size4x = mem3.szMaster*4 | x;
+ if( mem3.szMaster < mem3.mnMaster ){
+ mem3.mnMaster = mem3.szMaster;
}
- return (void*)&mem.aPool[newi];
+ return (void*)&mem3.aPool[newi];
}
}
/*
** *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[].
+** mem3.aiSmall[] or mem3.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
+** If it sees a chunk that is larger than mem3.iMaster, it replaces
+** the current mem3.iMaster with the new larger chunk. In order for
+** this mem3.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
static void memsys3Merge(u32 *pRoot){
u32 iNext, prev, size, i, x;
- assert( sqlite3_mutex_held(mem.mutex) );
+ assert( sqlite3_mutex_held(mem3.mutex) );
for(i=*pRoot; i>0; i=iNext){
- iNext = mem.aPool[i].u.list.next;
- size = mem.aPool[i-1].u.hdr.size4x;
+ iNext = mem3.aPool[i].u.list.next;
+ size = mem3.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;
+ assert( i > mem3.aPool[i-1].u.hdr.prevSize );
+ prev = i - mem3.aPool[i-1].u.hdr.prevSize;
if( prev==iNext ){
- iNext = mem.aPool[prev].u.list.next;
+ iNext = mem3.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;
+ x = mem3.aPool[prev-1].u.hdr.size4x & 2;
+ mem3.aPool[prev-1].u.hdr.size4x = size*4 | x;
+ mem3.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;
+ if( size>mem3.szMaster ){
+ mem3.iMaster = i;
+ mem3.szMaster = size;
}
}
}
int nBlock;
int toFree;
- assert( sqlite3_mutex_held(mem.mutex) );
+ assert( sqlite3_mutex_held(mem3.mutex) );
assert( sizeof(Mem3Block)==8 );
if( nByte<=12 ){
nBlock = 2;
}else{
nBlock = (nByte + 11)/8;
}
- assert( nBlock >= 2 );
+ assert( nBlock>=2 );
/* STEP 1:
** Look for an entry of the correct size in either the small
** successful most of the time (about 9 times out of 10).
*/
if( nBlock <= MX_SMALL ){
- i = mem.aiSmall[nBlock-2];
+ i = mem3.aiSmall[nBlock-2];
if( i>0 ){
- memsys3UnlinkFromList(i, &mem.aiSmall[nBlock-2]);
+ memsys3UnlinkFromList(i, &mem3.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]);
+ for(i=mem3.aiHash[hash]; i>0; i=mem3.aPool[i].u.list.next){
+ if( mem3.aPool[i-1].u.hdr.size4x/4==nBlock ){
+ memsys3UnlinkFromList(i, &mem3.aiHash[hash]);
return memsys3Checkout(i, nBlock);
}
}
** 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 ){
+ if( mem3.szMaster>=nBlock ){
return memsys3FromMaster(nBlock);
}
** of the end of the master chunk. This step happens very
** rarely (we hope!)
*/
- for(toFree=nBlock*16; toFree<SQLITE_MEMORY_SIZE*2; toFree *= 2){
+ for(toFree=nBlock*16; toFree<(mem3.nPool*16); toFree *= 2){
memsys3OutOfMemory(toFree);
- if( mem.iMaster ){
- memsys3Link(mem.iMaster);
- mem.iMaster = 0;
- mem.szMaster = 0;
+ if( mem3.iMaster ){
+ memsys3Link(mem3.iMaster);
+ mem3.iMaster = 0;
+ mem3.szMaster = 0;
}
for(i=0; i<N_HASH; i++){
- memsys3Merge(&mem.aiHash[i]);
+ memsys3Merge(&mem3.aiHash[i]);
}
for(i=0; i<MX_SMALL-1; i++){
- memsys3Merge(&mem.aiSmall[i]);
+ memsys3Merge(&mem3.aiSmall[i]);
}
- if( mem.szMaster ){
- memsys3Unlink(mem.iMaster);
- if( mem.szMaster>=nBlock ){
+ if( mem3.szMaster ){
+ memsys3Unlink(mem3.iMaster);
+ if( mem3.szMaster>=nBlock ){
return memsys3FromMaster(nBlock);
}
}
Mem3Block *p = (Mem3Block*)pOld;
int i;
u32 size, x;
- assert( sqlite3_mutex_held(mem.mutex) );
- assert( p>mem.aPool && p<&mem.aPool[SQLITE_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_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;
+ assert( sqlite3_mutex_held(mem3.mutex) );
+ assert( p>mem3.aPool && p<&mem3.aPool[mem3.nPool] );
+ i = p - mem3.aPool;
+ assert( (mem3.aPool[i-1].u.hdr.size4x&1)==1 );
+ size = mem3.aPool[i-1].u.hdr.size4x/4;
+ assert( i+size<=mem3.nPool+1 );
+ mem3.aPool[i-1].u.hdr.size4x &= ~1;
+ mem3.aPool[i+size-1].u.hdr.prevSize = size;
+ mem3.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;
+ if( mem3.iMaster ){
+ while( (mem3.aPool[mem3.iMaster-1].u.hdr.size4x&2)==0 ){
+ size = mem3.aPool[mem3.iMaster-1].u.hdr.prevSize;
+ mem3.iMaster -= size;
+ mem3.szMaster += size;
+ memsys3Unlink(mem3.iMaster);
+ x = mem3.aPool[mem3.iMaster-1].u.hdr.size4x & 2;
+ mem3.aPool[mem3.iMaster-1].u.hdr.size4x = mem3.szMaster*4 | x;
+ mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.prevSize = mem3.szMaster;
}
- 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;
+ x = mem3.aPool[mem3.iMaster-1].u.hdr.size4x & 2;
+ while( (mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.size4x&1)==0 ){
+ memsys3Unlink(mem3.iMaster+mem3.szMaster);
+ mem3.szMaster += mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.size4x/4;
+ mem3.aPool[mem3.iMaster-1].u.hdr.size4x = mem3.szMaster*4 | x;
+ mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.prevSize = mem3.szMaster;
}
}
}
/*
-** Allocate nBytes of memory
+** Allocate nBytes of memory.
*/
-void *sqlite3_malloc(int nBytes){
- sqlite3_int64 *p = 0;
- if( nBytes>0 ){
- memsys3Enter();
- p = memsys3Malloc(nBytes);
- sqlite3_mutex_leave(mem.mutex);
- }
+static void *mempoolMalloc(int nBytes){
+ sqlite3_int64 *p;
+ assert( nBytes>0 ); /* malloc.c filters out 0 byte requests */
+ memsys3Enter();
+ p = memsys3Malloc(nBytes);
+ memsys3Leave();
return (void*)p;
}
/*
** Free memory.
*/
-void sqlite3_free(void *pPrior){
- if( pPrior==0 ){
- return;
- }
- assert( mem.mutex!=0 );
- sqlite3_mutex_enter(mem.mutex);
+void mempoolFree(void *pPrior){
+ assert( pPrior );
+ memsys3Enter();
memsys3Free(pPrior);
- sqlite3_mutex_leave(mem.mutex);
+ memsys3Leave();
+}
+
+/*
+** Return the size of an outstanding allocation, in bytes. The
+** size returned omits the 8-byte header overhead. This only
+** works for chunks that are currently checked out.
+*/
+static int mempoolSize(void *p){
+ Mem3Block *pBlock = (Mem3Block*)p;
+ assert( pBlock );
+ assert( (pBlock[-1].u.hdr.size4x&1)!=0 );
+ return (pBlock[-1].u.hdr.size4x&~3)*2 - 4;
}
/*
** Change the size of an existing memory allocation
*/
-void *sqlite3_realloc(void *pPrior, int nBytes){
+void *mempoolRealloc(void *pPrior, int nBytes){
int nOld;
void *p;
if( pPrior==0 ){
sqlite3_free(pPrior);
return 0;
}
- assert( mem.mutex!=0 );
- nOld = sqlite3MallocSize(pPrior);
+ nOld = mempoolSize(pPrior);
if( nBytes<=nOld && nBytes>=nOld-128 ){
return pPrior;
}
- sqlite3_mutex_enter(mem.mutex);
- p = memsys3Malloc(nBytes);
+ memsys3Enter();
+ p = mempoolMalloc(nBytes);
if( p ){
if( nOld<nBytes ){
memcpy(p, pPrior, nOld);
}else{
memcpy(p, pPrior, nBytes);
}
- memsys3Free(pPrior);
+ mempoolFree(pPrior);
}
- sqlite3_mutex_leave(mem.mutex);
+ memsys3Leave();
return p;
}
+/*
+** Round up a request size to the next valid allocation size.
+*/
+static int mempoolRoundup(int n){
+ /* TODO: Fix me */
+ return n;
+}
+
+/*
+** Initialize this module.
+*/
+static int mempoolInit(void *NotUsed){
+ return SQLITE_OK;
+}
+
+/*
+** Deinitialize this module.
+*/
+static void mempoolShutdown(void *NotUsed){
+ return;
+}
+
+
+
/*
** Open the file indicated and write a log of all unfreed memory
** allocations into that log.
*/
+#if 0
void sqlite3MemdebugDump(const char *zFilename){
#ifdef SQLITE_DEBUG
FILE *out;
memsys3Enter();
fprintf(out, "CHUNKS:\n");
for(i=1; i<=SQLITE_MEMORY_SIZE/8; i+=size/4){
- size = mem.aPool[i-1].u.hdr.size4x;
+ size = mem3.aPool[i-1].u.hdr.size4x;
if( size/4<=1 ){
- fprintf(out, "%p size error\n", &mem.aPool[i]);
+ fprintf(out, "%p size error\n", &mem3.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]);
+ if( (size&1)==0 && mem3.aPool[i+size/4-1].u.hdr.prevSize!=size/4 ){
+ fprintf(out, "%p tail size does not match\n", &mem3.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]);
+ if( ((mem3.aPool[i+size/4-1].u.hdr.size4x&2)>>1)!=(size&1) ){
+ fprintf(out, "%p tail checkout bit is incorrect\n", &mem3.aPool[i]);
assert( 0 );
break;
}
if( size&1 ){
- fprintf(out, "%p %6d bytes checked out\n", &mem.aPool[i], (size/4)*8-8);
+ fprintf(out, "%p %6d bytes checked out\n", &mem3.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**" : "");
+ fprintf(out, "%p %6d bytes free%s\n", &mem3.aPool[i], (size/4)*8-8,
+ i==mem3.iMaster ? " **master**" : "");
}
}
for(i=0; i<MX_SMALL-1; i++){
- if( mem.aiSmall[i]==0 ) continue;
+ if( mem3.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);
+ for(j = mem3.aiSmall[i]; j>0; j=mem3.aPool[j].u.list.next){
+ fprintf(out, " %p(%d)", &mem3.aPool[j],
+ (mem3.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;
+ if( mem3.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);
+ for(j = mem3.aiHash[i]; j>0; j=mem3.aPool[j].u.list.next){
+ fprintf(out, " %p(%d)", &mem3.aPool[j],
+ (mem3.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_MEMORY_SIZE - mem.szMaster*8);
- fprintf(out, "mxUsed=%d\n", SQLITE_MEMORY_SIZE - mem.mnMaster*8);
- sqlite3_mutex_leave(mem.mutex);
+ fprintf(out, "master=%d\n", mem3.iMaster);
+ fprintf(out, "nowUsed=%d\n", SQLITE_MEMORY_SIZE - mem3.szMaster*8);
+ fprintf(out, "mxUsed=%d\n", SQLITE_MEMORY_SIZE - mem3.mnMaster*8);
+ sqlite3_mutex_leave(mem3.mutex);
if( out==stdout ){
fflush(stdout);
}else{
}
#endif
}
+#endif
+/*
+** This routine is the only routine in this file with external
+** linkage.
+**
+** Populate the low-level memory allocation function pointers in
+** sqlite3Config.m with pointers to the routines in this file. The
+** arguments specify the block of memory to manage.
+**
+** This routine is only called by sqlite3_config(), and therefore
+** is not required to be threadsafe (it is not).
+*/
+void sqlite3MemSetMempool(u8 *pBlock, int nBlock){
+ static const sqlite3_mem_methods mempoolMethods = {
+ mempoolMalloc,
+ mempoolFree,
+ mempoolRealloc,
+ mempoolSize,
+ mempoolRoundup,
+ mempoolInit,
+ mempoolShutdown,
+ 0
+ };
+
+ /* Configure the functions to call to allocate memory. */
+ sqlite3_config(SQLITE_CONFIG_MALLOC, &mempoolMethods);
+
+ /* Store a pointer to the memory block in global structure mem3. */
+ assert( sizeof(Mem3Block)==8 );
+ mem3.aPool = (Mem3Block *)pBlock;
+ mem3.nPool = (nBlock / sizeof(Mem3Block)) - 2;
+
+ /* Initialize the master block. */
+ mem3.szMaster = mem3.nPool;
+ mem3.mnMaster = mem3.szMaster;
+ mem3.iMaster = 1;
+ mem3.aPool[0].u.hdr.size4x = (mem3.szMaster<<2) + 2;
+ mem3.aPool[mem3.nPool].u.hdr.prevSize = mem3.nPool;
+ mem3.aPool[mem3.nPool].u.hdr.size4x = 1;
+}
-#endif /* !SQLITE_MEMORY_SIZE */
+#endif /* SQLITE_MEMPOOL_MALLOC */
projects / thirdparty / sqlite.git / commitdiff
