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mirror of https://github.com/sqlite/sqlite.git synced 2025-07-24 22:22:08 +03:00

Refactor the implementation of the scratch memory allocator. Add the

SQLITE_TESTCTRL_SCRATCHMALLOC interface to facilitate testing.

FossilOrigin-Name: a3475ddfbe4526e6e0b334fd1376ee7c31508b80
This commit is contained in:
drh
2010-08-27 17:16:44 +00:00
parent 50d1b5f363
commit badc980afa
6 changed files with 115 additions and 102 deletions

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@ -1,8 +1,8 @@
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
C Remove\sunnecessary\scode\sfrom\smalloc.c.\s\sEnhance\spcache1.c\sso\sthat\sis\stries\nto\sreuse\sexisting\spages,\srather\sthan\screate\snew\spages,\swhen\sSQLite\sis\sunder\nmemory\spressure.\s\s"Memory\spressure"\smeans\sthat\sSQLITE_CONFIG_PAGECACHE\smemory\nis\snearly\sexhausted\sor\ssqlite3_soft_heap_limit()\shas\sbeen\sreached.
D 2010-08-27T12:21:06
C Refactor\sthe\simplementation\sof\sthe\sscratch\smemory\sallocator.\s\sAdd\sthe\nSQLITE_TESTCTRL_SCRATCHMALLOC\sinterface\sto\sfacilitate\stesting.
D 2010-08-27T17:16:45
F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
F Makefile.in 543f91f24cd7fee774ecc0a61c19704c0c3e78fd
F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@ -139,8 +139,8 @@ F src/journal.c 552839e54d1bf76fb8f7abe51868b66acacf6a0e
F src/legacy.c a199d7683d60cef73089e892409113e69c23a99f
F src/lempar.c 7f026423f4d71d989e719a743f98a1cbd4e6d99e
F src/loadext.c 6d422ea91cf3d2d00408c5a8f2391cd458da85f8
F src/main.c 13c874909c9e2eeb75fe3c7bf021d52a5888acb1
F src/malloc.c e81193f1b5ac8ff744477253f1a04e0ac579c597
F src/main.c bdd23be253843d3f34faa8f5bd3f92ebbf05b94b
F src/malloc.c f34c9253326fcd2dad0041801992ccf18ddd6ab5
F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
F src/mem1.c 89d4ea8d5cdd55635cbaa48ad53132af6294cbb2
F src/mem2.c 9e5f72e38573db9598fe60d3fa530d473cc8714e
@ -174,7 +174,7 @@ F src/resolve.c 1c0f32b64f8e3f555fe1f732f9d6f501a7f05706
F src/rowset.c 69afa95a97c524ba6faf3805e717b5b7ae85a697
F src/select.c 8add6cab889fc02e1492eda8dba462ccf11f51dd
F src/shell.c 8517fc1f9c59ae4007e6cc8b9af91ab231ea2056
F src/sqlite.h.in 76e41cea494cc3b2397f02ad702be0bee0559bb6
F src/sqlite.h.in 60a40abb36376b4cdf6a9ac7604ed5d3ea2d0bf8
F src/sqlite3ext.h 69dfb8116af51b84a029cddb3b35062354270c89
F src/sqliteInt.h 78ed6bd32777ad06a8b9910d17307aeeae555485
F src/sqliteLimit.h a17dcd3fb775d63b64a43a55c54cb282f9726f44
@ -522,7 +522,7 @@ F test/malloc_common.tcl f4a04b7a733eb114a3da16eb39035cde2c851220
F test/manydb.test b3d3bc4c25657e7f68d157f031eb4db7b3df0d3c
F test/memdb.test 0825155b2290e900264daaaf0334b6dfe69ea498
F test/memleak.test 10b9c6c57e19fc68c32941495e9ba1c50123f6e2
F test/memsubsys1.test 5cdd6aa68f17dafe38549f3c2e62bae1afbd96fd
F test/memsubsys1.test ef3d2af85bd55b8136e7fffd3b66e38e7864f32c
F test/memsubsys2.test 72a731225997ad5e8df89fdbeae9224616b6aecc
F test/minmax.test 722d80816f7e096bf2c04f4111f1a6c1ba65453d
F test/minmax2.test 33504c01a03bd99226144e4b03f7631a274d66e0
@ -850,14 +850,14 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
P 9616df8c47ababc2d148f0ab6286efa84bd990fb
R 0d182eef4d36dd7c8dd068fdaf1d817b
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R 9667b04fa2c6e7e750d5c74a6bbee707
U drh
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Z c2de87f687a677d94fa81a950a4c025c
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@ -1 +1 @@
51049479a8577e03cc353f71f6e13a10c8323d91
a3475ddfbe4526e6e0b334fd1376ee7c31508b80

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@ -2513,6 +2513,22 @@ int sqlite3_test_control(int op, ...){
break;
}
/* sqlite3_test_control(SQLITE_TESTCTRL_SCRATCHMALLOC, sz, &pNew, pFree);
**
** Pass pFree into sqlite3ScratchFree().
** If sz>0 then allocate a scratch buffer into pNew.
*/
case SQLITE_TESTCTRL_SCRATCHMALLOC: {
void *pFree, **ppNew;
int sz;
sz = va_arg(ap, int);
ppNew = va_arg(ap, void**);
pFree = va_arg(ap, void*);
if( sz ) *ppNew = sqlite3ScratchMalloc(sz);
sqlite3ScratchFree(pFree);
break;
}
}
va_end(ap);
#endif /* SQLITE_OMIT_BUILTIN_TEST */

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@ -71,14 +71,18 @@ int sqlite3_release_memory(int n){
#endif
}
/*
** An instance of the following object records the location of
** each unused scratch buffer.
*/
typedef struct ScratchFreeslot {
struct ScratchFreeslot *pNext; /* Next unused scratch buffer */
} ScratchFreeslot;
/*
** State information local to the memory allocation subsystem.
*/
static SQLITE_WSD struct Mem0Global {
/* Number of free pages for scratch and page-cache memory */
u32 nScratchFree;
u32 nPageFree;
sqlite3_mutex *mutex; /* Mutex to serialize access */
/*
@ -92,18 +96,21 @@ static SQLITE_WSD struct Mem0Global {
void *alarmArg;
/*
** Pointers to the end of sqlite3GlobalConfig.pScratch and
** sqlite3GlobalConfig.pPage to a block of memory that records
** which pages are available.
** Pointers to the end of sqlite3GlobalConfig.pScratch memory
** (so that a range test can be used to determine if an allocation
** being freed came from pScratch) and a pointer to the list of
** unused scratch allocations.
*/
u32 *aScratchFree;
void *pScratchEnd;
ScratchFreeslot *pScratchFree;
u32 nScratchFree;
/*
** True if heap is nearly "full" where "full" is defined by the
** sqlite3_soft_heap_limit() setting.
*/
int nearlyFull;
} mem0 = { 0, 0, 0, 0, 0, 0, 0, 0 };
} mem0 = { 0, 0, 0, 0, 0, 0, 0 };
#define mem0 GLOBAL(struct Mem0Global, mem0)
@ -120,15 +127,25 @@ int sqlite3MallocInit(void){
}
if( sqlite3GlobalConfig.pScratch && sqlite3GlobalConfig.szScratch>=100
&& sqlite3GlobalConfig.nScratch>=0 ){
int i;
sqlite3GlobalConfig.szScratch = ROUNDDOWN8(sqlite3GlobalConfig.szScratch-4);
mem0.aScratchFree = (u32*)&((char*)sqlite3GlobalConfig.pScratch)
[sqlite3GlobalConfig.szScratch*sqlite3GlobalConfig.nScratch];
for(i=0; i<sqlite3GlobalConfig.nScratch; i++){ mem0.aScratchFree[i] = i; }
mem0.nScratchFree = sqlite3GlobalConfig.nScratch;
int i, n, sz;
ScratchFreeslot *pSlot;
sz = ROUNDDOWN8(sqlite3GlobalConfig.szScratch);
sqlite3GlobalConfig.szScratch = sz;
pSlot = (ScratchFreeslot*)sqlite3GlobalConfig.pScratch;
n = sqlite3GlobalConfig.nScratch;
mem0.pScratchFree = pSlot;
mem0.nScratchFree = n;
for(i=0; i<n-1; i++){
pSlot->pNext = (ScratchFreeslot*)(sz+(char*)pSlot);
pSlot = pSlot->pNext;
}
pSlot->pNext = 0;
mem0.pScratchEnd = (void*)&pSlot[1];
}else{
mem0.pScratchEnd = 0;
sqlite3GlobalConfig.pScratch = 0;
sqlite3GlobalConfig.szScratch = 0;
sqlite3GlobalConfig.nScratch = 0;
}
if( sqlite3GlobalConfig.pPage==0 || sqlite3GlobalConfig.szPage<512
|| sqlite3GlobalConfig.nPage<1 ){
@ -327,59 +344,61 @@ void *sqlite3ScratchMalloc(int n){
void *p;
assert( n>0 );
sqlite3_mutex_enter(mem0.mutex);
if( mem0.nScratchFree && sqlite3GlobalConfig.szScratch>=n ){
p = mem0.pScratchFree;
mem0.pScratchFree = mem0.pScratchFree->pNext;
mem0.nScratchFree--;
sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_USED, 1);
sqlite3StatusSet(SQLITE_STATUS_SCRATCH_SIZE, n);
}else{
if( sqlite3GlobalConfig.bMemstat ){
sqlite3StatusSet(SQLITE_STATUS_SCRATCH_SIZE, n);
n = mallocWithAlarm(n, &p);
if( p ) sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_OVERFLOW, n);
}else{
p = sqlite3GlobalConfig.m.xMalloc(n);
}
sqlite3MemdebugSetType(p, MEMTYPE_SCRATCH);
}
sqlite3_mutex_leave(mem0.mutex);
#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
/* Verify that no more than two scratch allocation per thread
** is outstanding at one time. (This is only checked in the
/* Verify that no more than two scratch allocations per thread
** are outstanding at one time. (This is only checked in the
** single-threaded case since checking in the multi-threaded case
** would be much more complicated.) */
assert( scratchAllocOut<=1 );
#endif
if( sqlite3GlobalConfig.szScratch<n ){
goto scratch_overflow;
}else{
sqlite3_mutex_enter(mem0.mutex);
if( mem0.nScratchFree==0 ){
sqlite3_mutex_leave(mem0.mutex);
goto scratch_overflow;
}else{
int i;
i = mem0.aScratchFree[--mem0.nScratchFree];
i *= sqlite3GlobalConfig.szScratch;
sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_USED, 1);
sqlite3StatusSet(SQLITE_STATUS_SCRATCH_SIZE, n);
sqlite3_mutex_leave(mem0.mutex);
p = (void*)&((char*)sqlite3GlobalConfig.pScratch)[i];
assert( (((u8*)p - (u8*)0) & 7)==0 );
}
}
#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
scratchAllocOut = p!=0;
if( p ) scratchAllocOut++;
#endif
return p;
scratch_overflow:
if( sqlite3GlobalConfig.bMemstat ){
sqlite3_mutex_enter(mem0.mutex);
sqlite3StatusSet(SQLITE_STATUS_SCRATCH_SIZE, n);
n = mallocWithAlarm(n, &p);
if( p ) sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_OVERFLOW, n);
sqlite3_mutex_leave(mem0.mutex);
}else{
p = sqlite3GlobalConfig.m.xMalloc(n);
}
sqlite3MemdebugSetType(p, MEMTYPE_SCRATCH);
#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
scratchAllocOut = p!=0;
#endif
return p;
}
void sqlite3ScratchFree(void *p){
if( p ){
if( sqlite3GlobalConfig.pScratch==0
|| p<sqlite3GlobalConfig.pScratch
|| p>=(void*)mem0.aScratchFree ){
#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
/* Verify that no more than two scratch allocation per thread
** is outstanding at one time. (This is only checked in the
** single-threaded case since checking in the multi-threaded case
** would be much more complicated.) */
assert( scratchAllocOut>=1 && scratchAllocOut<=2 );
scratchAllocOut--;
#endif
if( p>=sqlite3GlobalConfig.pScratch && p<mem0.pScratchEnd ){
/* Release memory from the SQLITE_CONFIG_SCRATCH allocation */
ScratchFreeslot *pSlot;
pSlot = (ScratchFreeslot*)p;
sqlite3_mutex_enter(mem0.mutex);
pSlot->pNext = mem0.pScratchFree;
mem0.pScratchFree = pSlot;
mem0.nScratchFree++;
assert( mem0.nScratchFree<=sqlite3GlobalConfig.nScratch );
sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_USED, -1);
sqlite3_mutex_leave(mem0.mutex);
}else{
/* Release memory back to the heap */
assert( sqlite3MemdebugHasType(p, MEMTYPE_SCRATCH) );
assert( sqlite3MemdebugNoType(p, ~MEMTYPE_SCRATCH) );
sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
@ -394,26 +413,6 @@ void sqlite3ScratchFree(void *p){
}else{
sqlite3GlobalConfig.m.xFree(p);
}
}else{
int i;
i = (int)((u8*)p - (u8*)sqlite3GlobalConfig.pScratch);
i /= sqlite3GlobalConfig.szScratch;
assert( i>=0 && i<sqlite3GlobalConfig.nScratch );
sqlite3_mutex_enter(mem0.mutex);
assert( mem0.nScratchFree<(u32)sqlite3GlobalConfig.nScratch );
mem0.aScratchFree[mem0.nScratchFree++] = i;
sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_USED, -1);
sqlite3_mutex_leave(mem0.mutex);
#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
/* Verify that no more than two scratch allocation per thread
** is outstanding at one time. (This is only checked in the
** single-threaded case since checking in the multi-threaded case
** would be much more complicated.) */
assert( scratchAllocOut>=1 && scratchAllocOut<=2 );
scratchAllocOut = 0;
#endif
}
}
}

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@ -1257,15 +1257,14 @@ struct sqlite3_mem_methods {
** aligned memory buffer from which the scrach allocations will be
** drawn, the size of each scratch allocation (sz),
** and the maximum number of scratch allocations (N). The sz
** argument must be a multiple of 16. The sz parameter should be a few bytes
** larger than the actual scratch space required due to internal overhead.
** argument must be a multiple of 16.
** The first argument must be a pointer to an 8-byte aligned buffer
** of at least sz*N bytes of memory.
** ^SQLite will use no more than one scratch buffer per thread. So
** N should be set to the expected maximum number of threads. ^SQLite will
** never require a scratch buffer that is more than 6 times the database
** page size. ^If SQLite needs needs additional scratch memory beyond
** what is provided by this configuration option, then
** ^SQLite will use no more than two scratch buffers per thread. So
** N should be set to twice the expected maximum number of threads.
** ^SQLite will never require a scratch buffer that is more than 6
** times the database page size. ^If SQLite needs needs additional
** scratch memory beyond what is provided by this configuration option, then
** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>
**
** <dt>SQLITE_CONFIG_PAGECACHE</dt>
@ -1285,8 +1284,7 @@ struct sqlite3_mem_methods {
** memory needs for the first N pages that it adds to cache. ^If additional
** page cache memory is needed beyond what is provided by this option, then
** SQLite goes to [sqlite3_malloc()] for the additional storage space.
** ^The implementation might use one or more of the N buffers to hold
** memory accounting information. The pointer in the first argument must
** The pointer in the first argument must
** be aligned to an 8-byte boundary or subsequent behavior of SQLite
** will be undefined.</dd>
**
@ -5100,7 +5098,8 @@ int sqlite3_test_control(int op, ...);
#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
#define SQLITE_TESTCTRL_ISKEYWORD 16
#define SQLITE_TESTCTRL_PGHDRSZ 17
#define SQLITE_TESTCTRL_LAST 17
#define SQLITE_TESTCTRL_SCRATCHMALLOC 18
#define SQLITE_TESTCTRL_LAST 18
/*
** CAPI3REF: SQLite Runtime Status

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@ -11,7 +11,6 @@
#
# This file contains tests of the memory allocation subsystem
#
# $Id: memsubsys1.test,v 1.17 2009/07/18 14:36:24 danielk1977 Exp $
set testdir [file dirname $argv0]
source $testdir/tester.tcl