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Diffstat (limited to '')
| -rw-r--r-- | src/malloc.c | 900 |
1 files changed, 900 insertions, 0 deletions
diff --git a/src/malloc.c b/src/malloc.c new file mode 100644 index 0000000..3567506 --- /dev/null +++ b/src/malloc.c @@ -0,0 +1,900 @@ +/* +** 2001 September 15 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +************************************************************************* +** +** Memory allocation functions used throughout sqlite. +*/ +#include "sqliteInt.h" +#include <stdarg.h> + +/* +** Attempt to release up to n bytes of non-essential memory currently +** held by SQLite. An example of non-essential memory is memory used to +** cache database pages that are not currently in use. +*/ +int sqlite3_release_memory(int n){ +#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT + return sqlite3PcacheReleaseMemory(n); +#else + /* IMPLEMENTATION-OF: R-34391-24921 The sqlite3_release_memory() routine + ** is a no-op returning zero if SQLite is not compiled with + ** SQLITE_ENABLE_MEMORY_MANAGEMENT. */ + UNUSED_PARAMETER(n); + return 0; +#endif +} + +/* +** Default value of the hard heap limit. 0 means "no limit". +*/ +#ifndef SQLITE_MAX_MEMORY +# define SQLITE_MAX_MEMORY 0 +#endif + +/* +** State information local to the memory allocation subsystem. +*/ +static SQLITE_WSD struct Mem0Global { + sqlite3_mutex *mutex; /* Mutex to serialize access */ + sqlite3_int64 alarmThreshold; /* The soft heap limit */ + sqlite3_int64 hardLimit; /* The hard upper bound on memory */ + + /* + ** True if heap is nearly "full" where "full" is defined by the + ** sqlite3_soft_heap_limit() setting. + */ + int nearlyFull; +} mem0 = { 0, SQLITE_MAX_MEMORY, SQLITE_MAX_MEMORY, 0 }; + +#define mem0 GLOBAL(struct Mem0Global, mem0) + +/* +** Return the memory allocator mutex. sqlite3_status() needs it. +*/ +sqlite3_mutex *sqlite3MallocMutex(void){ + return mem0.mutex; +} + +#ifndef SQLITE_OMIT_DEPRECATED +/* +** Deprecated external interface. It used to set an alarm callback +** that was invoked when memory usage grew too large. Now it is a +** no-op. +*/ +int sqlite3_memory_alarm( + void(*xCallback)(void *pArg, sqlite3_int64 used,int N), + void *pArg, + sqlite3_int64 iThreshold +){ + (void)xCallback; + (void)pArg; + (void)iThreshold; + return SQLITE_OK; +} +#endif + +/* +** Set the soft heap-size limit for the library. An argument of +** zero disables the limit. A negative argument is a no-op used to +** obtain the return value. +** +** The return value is the value of the heap limit just before this +** interface was called. +** +** If the hard heap limit is enabled, then the soft heap limit cannot +** be disabled nor raised above the hard heap limit. +*/ +sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 n){ + sqlite3_int64 priorLimit; + sqlite3_int64 excess; + sqlite3_int64 nUsed; +#ifndef SQLITE_OMIT_AUTOINIT + int rc = sqlite3_initialize(); + if( rc ) return -1; +#endif + sqlite3_mutex_enter(mem0.mutex); + priorLimit = mem0.alarmThreshold; + if( n<0 ){ + sqlite3_mutex_leave(mem0.mutex); + return priorLimit; + } + if( mem0.hardLimit>0 && (n>mem0.hardLimit || n==0) ){ + n = mem0.hardLimit; + } + mem0.alarmThreshold = n; + nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED); + AtomicStore(&mem0.nearlyFull, n>0 && n<=nUsed); + sqlite3_mutex_leave(mem0.mutex); + excess = sqlite3_memory_used() - n; + if( excess>0 ) sqlite3_release_memory((int)(excess & 0x7fffffff)); + return priorLimit; +} +void sqlite3_soft_heap_limit(int n){ + if( n<0 ) n = 0; + sqlite3_soft_heap_limit64(n); +} + +/* +** Set the hard heap-size limit for the library. An argument of zero +** disables the hard heap limit. A negative argument is a no-op used +** to obtain the return value without affecting the hard heap limit. +** +** The return value is the value of the hard heap limit just prior to +** calling this interface. +** +** Setting the hard heap limit will also activate the soft heap limit +** and constrain the soft heap limit to be no more than the hard heap +** limit. +*/ +sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 n){ + sqlite3_int64 priorLimit; +#ifndef SQLITE_OMIT_AUTOINIT + int rc = sqlite3_initialize(); + if( rc ) return -1; +#endif + sqlite3_mutex_enter(mem0.mutex); + priorLimit = mem0.hardLimit; + if( n>=0 ){ + mem0.hardLimit = n; + if( n<mem0.alarmThreshold || mem0.alarmThreshold==0 ){ + mem0.alarmThreshold = n; + } + } + sqlite3_mutex_leave(mem0.mutex); + return priorLimit; +} + + +/* +** Initialize the memory allocation subsystem. +*/ +int sqlite3MallocInit(void){ + int rc; + if( sqlite3GlobalConfig.m.xMalloc==0 ){ + sqlite3MemSetDefault(); + } + mem0.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM); + if( sqlite3GlobalConfig.pPage==0 || sqlite3GlobalConfig.szPage<512 + || sqlite3GlobalConfig.nPage<=0 ){ + sqlite3GlobalConfig.pPage = 0; + sqlite3GlobalConfig.szPage = 0; + } + rc = sqlite3GlobalConfig.m.xInit(sqlite3GlobalConfig.m.pAppData); + if( rc!=SQLITE_OK ) memset(&mem0, 0, sizeof(mem0)); + return rc; +} + +/* +** Return true if the heap is currently under memory pressure - in other +** words if the amount of heap used is close to the limit set by +** sqlite3_soft_heap_limit(). +*/ +int sqlite3HeapNearlyFull(void){ + return AtomicLoad(&mem0.nearlyFull); +} + +/* +** Deinitialize the memory allocation subsystem. +*/ +void sqlite3MallocEnd(void){ + if( sqlite3GlobalConfig.m.xShutdown ){ + sqlite3GlobalConfig.m.xShutdown(sqlite3GlobalConfig.m.pAppData); + } + memset(&mem0, 0, sizeof(mem0)); +} + +/* +** Return the amount of memory currently checked out. +*/ +sqlite3_int64 sqlite3_memory_used(void){ + sqlite3_int64 res, mx; + sqlite3_status64(SQLITE_STATUS_MEMORY_USED, &res, &mx, 0); + return res; +} + +/* +** 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 res, mx; + sqlite3_status64(SQLITE_STATUS_MEMORY_USED, &res, &mx, resetFlag); + return mx; +} + +/* +** Trigger the alarm +*/ +static void sqlite3MallocAlarm(int nByte){ + if( mem0.alarmThreshold<=0 ) return; + sqlite3_mutex_leave(mem0.mutex); + sqlite3_release_memory(nByte); + sqlite3_mutex_enter(mem0.mutex); +} + +/* +** Do a memory allocation with statistics and alarms. Assume the +** lock is already held. +*/ +static void mallocWithAlarm(int n, void **pp){ + void *p; + int nFull; + assert( sqlite3_mutex_held(mem0.mutex) ); + assert( n>0 ); + + /* In Firefox (circa 2017-02-08), xRoundup() is remapped to an internal + ** implementation of malloc_good_size(), which must be called in debug + ** mode and specifically when the DMD "Dark Matter Detector" is enabled + ** or else a crash results. Hence, do not attempt to optimize out the + ** following xRoundup() call. */ + nFull = sqlite3GlobalConfig.m.xRoundup(n); + + sqlite3StatusHighwater(SQLITE_STATUS_MALLOC_SIZE, n); + if( mem0.alarmThreshold>0 ){ + sqlite3_int64 nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED); + if( nUsed >= mem0.alarmThreshold - nFull ){ + AtomicStore(&mem0.nearlyFull, 1); + sqlite3MallocAlarm(nFull); + if( mem0.hardLimit ){ + nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED); + if( nUsed >= mem0.hardLimit - nFull ){ + *pp = 0; + return; + } + } + }else{ + AtomicStore(&mem0.nearlyFull, 0); + } + } + p = sqlite3GlobalConfig.m.xMalloc(nFull); +#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT + if( p==0 && mem0.alarmThreshold>0 ){ + sqlite3MallocAlarm(nFull); + p = sqlite3GlobalConfig.m.xMalloc(nFull); + } +#endif + if( p ){ + nFull = sqlite3MallocSize(p); + sqlite3StatusUp(SQLITE_STATUS_MEMORY_USED, nFull); + sqlite3StatusUp(SQLITE_STATUS_MALLOC_COUNT, 1); + } + *pp = p; +} + +/* +** Maximum size of any single memory allocation. +** +** This is not a limit on the total amount of memory used. This is +** a limit on the size parameter to sqlite3_malloc() and sqlite3_realloc(). +** +** The upper bound is slightly less than 2GiB: 0x7ffffeff == 2,147,483,391 +** This provides a 256-byte safety margin for defense against 32-bit +** signed integer overflow bugs when computing memory allocation sizes. +** Paranoid applications might want to reduce the maximum allocation size +** further for an even larger safety margin. 0x3fffffff or 0x0fffffff +** or even smaller would be reasonable upper bounds on the size of a memory +** allocations for most applications. +*/ +#ifndef SQLITE_MAX_ALLOCATION_SIZE +# define SQLITE_MAX_ALLOCATION_SIZE 2147483391 +#endif +#if SQLITE_MAX_ALLOCATION_SIZE>2147483391 +# error Maximum size for SQLITE_MAX_ALLOCATION_SIZE is 2147483391 +#endif + +/* +** Allocate memory. This routine is like sqlite3_malloc() except that it +** assumes the memory subsystem has already been initialized. +*/ +void *sqlite3Malloc(u64 n){ + void *p; + if( n==0 || n>SQLITE_MAX_ALLOCATION_SIZE ){ + p = 0; + }else if( sqlite3GlobalConfig.bMemstat ){ + sqlite3_mutex_enter(mem0.mutex); + mallocWithAlarm((int)n, &p); + sqlite3_mutex_leave(mem0.mutex); + }else{ + p = sqlite3GlobalConfig.m.xMalloc((int)n); + } + assert( EIGHT_BYTE_ALIGNMENT(p) ); /* IMP: R-11148-40995 */ + return p; +} + +/* +** This version of the memory allocation is for use by the application. +** First make sure the memory subsystem is initialized, then do the +** allocation. +*/ +void *sqlite3_malloc(int n){ +#ifndef SQLITE_OMIT_AUTOINIT + if( sqlite3_initialize() ) return 0; +#endif + return n<=0 ? 0 : sqlite3Malloc(n); +} +void *sqlite3_malloc64(sqlite3_uint64 n){ +#ifndef SQLITE_OMIT_AUTOINIT + if( sqlite3_initialize() ) return 0; +#endif + return sqlite3Malloc(n); +} + +/* +** TRUE if p is a lookaside memory allocation from db +*/ +#ifndef SQLITE_OMIT_LOOKASIDE +static int isLookaside(sqlite3 *db, const void *p){ + return SQLITE_WITHIN(p, db->lookaside.pStart, db->lookaside.pTrueEnd); +} +#else +#define isLookaside(A,B) 0 +#endif + +/* +** Return the size of a memory allocation previously obtained from +** sqlite3Malloc() or sqlite3_malloc(). +*/ +int sqlite3MallocSize(const void *p){ + assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) ); + return sqlite3GlobalConfig.m.xSize((void*)p); +} +static int lookasideMallocSize(sqlite3 *db, const void *p){ +#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE + return p<db->lookaside.pMiddle ? db->lookaside.szTrue : LOOKASIDE_SMALL; +#else + return db->lookaside.szTrue; +#endif +} +int sqlite3DbMallocSize(sqlite3 *db, const void *p){ + assert( p!=0 ); +#ifdef SQLITE_DEBUG + if( db==0 ){ + assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) ); + assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) ); + }else if( !isLookaside(db,p) ){ + assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) ); + assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) ); + } +#endif + if( db ){ + if( ((uptr)p)<(uptr)(db->lookaside.pTrueEnd) ){ +#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE + if( ((uptr)p)>=(uptr)(db->lookaside.pMiddle) ){ + assert( sqlite3_mutex_held(db->mutex) ); + return LOOKASIDE_SMALL; + } +#endif + if( ((uptr)p)>=(uptr)(db->lookaside.pStart) ){ + assert( sqlite3_mutex_held(db->mutex) ); + return db->lookaside.szTrue; + } + } + } + return sqlite3GlobalConfig.m.xSize((void*)p); +} +sqlite3_uint64 sqlite3_msize(void *p){ + assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) ); + assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) ); + return p ? sqlite3GlobalConfig.m.xSize(p) : 0; +} + +/* +** Free memory previously obtained from sqlite3Malloc(). +*/ +void sqlite3_free(void *p){ + if( p==0 ) return; /* IMP: R-49053-54554 */ + assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) ); + assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) ); + if( sqlite3GlobalConfig.bMemstat ){ + sqlite3_mutex_enter(mem0.mutex); + sqlite3StatusDown(SQLITE_STATUS_MEMORY_USED, sqlite3MallocSize(p)); + sqlite3StatusDown(SQLITE_STATUS_MALLOC_COUNT, 1); + sqlite3GlobalConfig.m.xFree(p); + sqlite3_mutex_leave(mem0.mutex); + }else{ + sqlite3GlobalConfig.m.xFree(p); + } +} + +/* +** Add the size of memory allocation "p" to the count in +** *db->pnBytesFreed. +*/ +static SQLITE_NOINLINE void measureAllocationSize(sqlite3 *db, void *p){ + *db->pnBytesFreed += sqlite3DbMallocSize(db,p); +} + +/* +** Free memory that might be associated with a particular database +** connection. Calling sqlite3DbFree(D,X) for X==0 is a harmless no-op. +** The sqlite3DbFreeNN(D,X) version requires that X be non-NULL. +*/ +void sqlite3DbFreeNN(sqlite3 *db, void *p){ + assert( db==0 || sqlite3_mutex_held(db->mutex) ); + assert( p!=0 ); + if( db ){ + if( ((uptr)p)<(uptr)(db->lookaside.pEnd) ){ +#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE + if( ((uptr)p)>=(uptr)(db->lookaside.pMiddle) ){ + LookasideSlot *pBuf = (LookasideSlot*)p; + assert( db->pnBytesFreed==0 ); +#ifdef SQLITE_DEBUG + memset(p, 0xaa, LOOKASIDE_SMALL); /* Trash freed content */ +#endif + pBuf->pNext = db->lookaside.pSmallFree; + db->lookaside.pSmallFree = pBuf; + return; + } +#endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */ + if( ((uptr)p)>=(uptr)(db->lookaside.pStart) ){ + LookasideSlot *pBuf = (LookasideSlot*)p; + assert( db->pnBytesFreed==0 ); +#ifdef SQLITE_DEBUG + memset(p, 0xaa, db->lookaside.szTrue); /* Trash freed content */ +#endif + pBuf->pNext = db->lookaside.pFree; + db->lookaside.pFree = pBuf; + return; + } + } + if( db->pnBytesFreed ){ + measureAllocationSize(db, p); + return; + } + } + assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) ); + assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) ); + assert( db!=0 || sqlite3MemdebugNoType(p, MEMTYPE_LOOKASIDE) ); + sqlite3MemdebugSetType(p, MEMTYPE_HEAP); + sqlite3_free(p); +} +void sqlite3DbNNFreeNN(sqlite3 *db, void *p){ + assert( db!=0 ); + assert( sqlite3_mutex_held(db->mutex) ); + assert( p!=0 ); + if( ((uptr)p)<(uptr)(db->lookaside.pEnd) ){ +#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE + if( ((uptr)p)>=(uptr)(db->lookaside.pMiddle) ){ + LookasideSlot *pBuf = (LookasideSlot*)p; + assert( db->pnBytesFreed==0 ); +#ifdef SQLITE_DEBUG + memset(p, 0xaa, LOOKASIDE_SMALL); /* Trash freed content */ +#endif + pBuf->pNext = db->lookaside.pSmallFree; + db->lookaside.pSmallFree = pBuf; + return; + } +#endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */ + if( ((uptr)p)>=(uptr)(db->lookaside.pStart) ){ + LookasideSlot *pBuf = (LookasideSlot*)p; + assert( db->pnBytesFreed==0 ); +#ifdef SQLITE_DEBUG + memset(p, 0xaa, db->lookaside.szTrue); /* Trash freed content */ +#endif + pBuf->pNext = db->lookaside.pFree; + db->lookaside.pFree = pBuf; + return; + } + } + if( db->pnBytesFreed ){ + measureAllocationSize(db, p); + return; + } + assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) ); + assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) ); + sqlite3MemdebugSetType(p, MEMTYPE_HEAP); + sqlite3_free(p); +} +void sqlite3DbFree(sqlite3 *db, void *p){ + assert( db==0 || sqlite3_mutex_held(db->mutex) ); + if( p ) sqlite3DbFreeNN(db, p); +} + +/* +** Change the size of an existing memory allocation +*/ +void *sqlite3Realloc(void *pOld, u64 nBytes){ + int nOld, nNew, nDiff; + void *pNew; + assert( sqlite3MemdebugHasType(pOld, MEMTYPE_HEAP) ); + assert( sqlite3MemdebugNoType(pOld, (u8)~MEMTYPE_HEAP) ); + if( pOld==0 ){ + return sqlite3Malloc(nBytes); /* IMP: R-04300-56712 */ + } + if( nBytes==0 ){ + sqlite3_free(pOld); /* IMP: R-26507-47431 */ + return 0; + } + if( nBytes>=0x7fffff00 ){ + /* The 0x7ffff00 limit term is explained in comments on sqlite3Malloc() */ + return 0; + } + nOld = sqlite3MallocSize(pOld); + /* IMPLEMENTATION-OF: R-46199-30249 SQLite guarantees that the second + ** argument to xRealloc is always a value returned by a prior call to + ** xRoundup. */ + nNew = sqlite3GlobalConfig.m.xRoundup((int)nBytes); + if( nOld==nNew ){ + pNew = pOld; + }else if( sqlite3GlobalConfig.bMemstat ){ + sqlite3_int64 nUsed; + sqlite3_mutex_enter(mem0.mutex); + sqlite3StatusHighwater(SQLITE_STATUS_MALLOC_SIZE, (int)nBytes); + nDiff = nNew - nOld; + if( nDiff>0 && (nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED)) >= + mem0.alarmThreshold-nDiff ){ + sqlite3MallocAlarm(nDiff); + if( mem0.hardLimit>0 && nUsed >= mem0.hardLimit - nDiff ){ + sqlite3_mutex_leave(mem0.mutex); + return 0; + } + } + pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew); +#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT + if( pNew==0 && mem0.alarmThreshold>0 ){ + sqlite3MallocAlarm((int)nBytes); + pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew); + } +#endif + if( pNew ){ + nNew = sqlite3MallocSize(pNew); + sqlite3StatusUp(SQLITE_STATUS_MEMORY_USED, nNew-nOld); + } + sqlite3_mutex_leave(mem0.mutex); + }else{ + pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew); + } + assert( EIGHT_BYTE_ALIGNMENT(pNew) ); /* IMP: R-11148-40995 */ + return pNew; +} + +/* +** The public interface to sqlite3Realloc. Make sure that the memory +** subsystem is initialized prior to invoking sqliteRealloc. +*/ +void *sqlite3_realloc(void *pOld, int n){ +#ifndef SQLITE_OMIT_AUTOINIT + if( sqlite3_initialize() ) return 0; +#endif + if( n<0 ) n = 0; /* IMP: R-26507-47431 */ + return sqlite3Realloc(pOld, n); +} +void *sqlite3_realloc64(void *pOld, sqlite3_uint64 n){ +#ifndef SQLITE_OMIT_AUTOINIT + if( sqlite3_initialize() ) return 0; +#endif + return sqlite3Realloc(pOld, n); +} + + +/* +** Allocate and zero memory. +*/ +void *sqlite3MallocZero(u64 n){ + void *p = sqlite3Malloc(n); + if( p ){ + memset(p, 0, (size_t)n); + } + return p; +} + +/* +** Allocate and zero memory. If the allocation fails, make +** the mallocFailed flag in the connection pointer. +*/ +void *sqlite3DbMallocZero(sqlite3 *db, u64 n){ + void *p; + testcase( db==0 ); + p = sqlite3DbMallocRaw(db, n); + if( p ) memset(p, 0, (size_t)n); + return p; +} + + +/* Finish the work of sqlite3DbMallocRawNN for the unusual and +** slower case when the allocation cannot be fulfilled using lookaside. +*/ +static SQLITE_NOINLINE void *dbMallocRawFinish(sqlite3 *db, u64 n){ + void *p; + assert( db!=0 ); + p = sqlite3Malloc(n); + if( !p ) sqlite3OomFault(db); + sqlite3MemdebugSetType(p, + (db->lookaside.bDisable==0) ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP); + return p; +} + +/* +** Allocate memory, either lookaside (if possible) or heap. +** If the allocation fails, set the mallocFailed flag in +** the connection pointer. +** +** If db!=0 and db->mallocFailed is true (indicating a prior malloc +** failure on the same database connection) then always return 0. +** Hence for a particular database connection, once malloc starts +** failing, it fails consistently until mallocFailed is reset. +** This is an important assumption. There are many places in the +** code that do things like this: +** +** int *a = (int*)sqlite3DbMallocRaw(db, 100); +** int *b = (int*)sqlite3DbMallocRaw(db, 200); +** if( b ) a[10] = 9; +** +** In other words, if a subsequent malloc (ex: "b") worked, it is assumed +** that all prior mallocs (ex: "a") worked too. +** +** The sqlite3MallocRawNN() variant guarantees that the "db" parameter is +** not a NULL pointer. +*/ +void *sqlite3DbMallocRaw(sqlite3 *db, u64 n){ + void *p; + if( db ) return sqlite3DbMallocRawNN(db, n); + p = sqlite3Malloc(n); + sqlite3MemdebugSetType(p, MEMTYPE_HEAP); + return p; +} +void *sqlite3DbMallocRawNN(sqlite3 *db, u64 n){ +#ifndef SQLITE_OMIT_LOOKASIDE + LookasideSlot *pBuf; + assert( db!=0 ); + assert( sqlite3_mutex_held(db->mutex) ); + assert( db->pnBytesFreed==0 ); + if( n>db->lookaside.sz ){ + if( !db->lookaside.bDisable ){ + db->lookaside.anStat[1]++; + }else if( db->mallocFailed ){ + return 0; + } + return dbMallocRawFinish(db, n); + } +#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE + if( n<=LOOKASIDE_SMALL ){ + if( (pBuf = db->lookaside.pSmallFree)!=0 ){ + db->lookaside.pSmallFree = pBuf->pNext; + db->lookaside.anStat[0]++; + return (void*)pBuf; + }else if( (pBuf = db->lookaside.pSmallInit)!=0 ){ + db->lookaside.pSmallInit = pBuf->pNext; + db->lookaside.anStat[0]++; + return (void*)pBuf; + } + } +#endif + if( (pBuf = db->lookaside.pFree)!=0 ){ + db->lookaside.pFree = pBuf->pNext; + db->lookaside.anStat[0]++; + return (void*)pBuf; + }else if( (pBuf = db->lookaside.pInit)!=0 ){ + db->lookaside.pInit = pBuf->pNext; + db->lookaside.anStat[0]++; + return (void*)pBuf; + }else{ + db->lookaside.anStat[2]++; + } +#else + assert( db!=0 ); + assert( sqlite3_mutex_held(db->mutex) ); + assert( db->pnBytesFreed==0 ); + if( db->mallocFailed ){ + return 0; + } +#endif + return dbMallocRawFinish(db, n); +} + +/* Forward declaration */ +static SQLITE_NOINLINE void *dbReallocFinish(sqlite3 *db, void *p, u64 n); + +/* +** Resize the block of memory pointed to by p to n bytes. If the +** resize fails, set the mallocFailed flag in the connection object. +*/ +void *sqlite3DbRealloc(sqlite3 *db, void *p, u64 n){ + assert( db!=0 ); + if( p==0 ) return sqlite3DbMallocRawNN(db, n); + assert( sqlite3_mutex_held(db->mutex) ); + if( ((uptr)p)<(uptr)db->lookaside.pEnd ){ +#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE + if( ((uptr)p)>=(uptr)db->lookaside.pMiddle ){ + if( n<=LOOKASIDE_SMALL ) return p; + }else +#endif + if( ((uptr)p)>=(uptr)db->lookaside.pStart ){ + if( n<=db->lookaside.szTrue ) return p; + } + } + return dbReallocFinish(db, p, n); +} +static SQLITE_NOINLINE void *dbReallocFinish(sqlite3 *db, void *p, u64 n){ + void *pNew = 0; + assert( db!=0 ); + assert( p!=0 ); + if( db->mallocFailed==0 ){ + if( isLookaside(db, p) ){ + pNew = sqlite3DbMallocRawNN(db, n); + if( pNew ){ + memcpy(pNew, p, lookasideMallocSize(db, p)); + sqlite3DbFree(db, p); + } + }else{ + assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) ); + assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) ); + sqlite3MemdebugSetType(p, MEMTYPE_HEAP); + pNew = sqlite3Realloc(p, n); + if( !pNew ){ + sqlite3OomFault(db); + } + sqlite3MemdebugSetType(pNew, + (db->lookaside.bDisable==0 ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP)); + } + } + return pNew; +} + +/* +** Attempt to reallocate p. If the reallocation fails, then free p +** and set the mallocFailed flag in the database connection. +*/ +void *sqlite3DbReallocOrFree(sqlite3 *db, void *p, u64 n){ + void *pNew; + pNew = sqlite3DbRealloc(db, p, n); + if( !pNew ){ + sqlite3DbFree(db, p); + } + return pNew; +} + +/* +** Make a copy of a string in memory obtained from sqliteMalloc(). These +** functions call sqlite3MallocRaw() directly instead of sqliteMalloc(). This +** is because when memory debugging is turned on, these two functions are +** called via macros that record the current file and line number in the +** ThreadData structure. +*/ +char *sqlite3DbStrDup(sqlite3 *db, const char *z){ + char *zNew; + size_t n; + if( z==0 ){ + return 0; + } + n = strlen(z) + 1; + zNew = sqlite3DbMallocRaw(db, n); + if( zNew ){ + memcpy(zNew, z, n); + } + return zNew; +} +char *sqlite3DbStrNDup(sqlite3 *db, const char *z, u64 n){ + char *zNew; + assert( db!=0 ); + assert( z!=0 || n==0 ); + assert( (n&0x7fffffff)==n ); + zNew = z ? sqlite3DbMallocRawNN(db, n+1) : 0; + if( zNew ){ + memcpy(zNew, z, (size_t)n); + zNew[n] = 0; + } + return zNew; +} + +/* +** The text between zStart and zEnd represents a phrase within a larger +** SQL statement. Make a copy of this phrase in space obtained form +** sqlite3DbMalloc(). Omit leading and trailing whitespace. +*/ +char *sqlite3DbSpanDup(sqlite3 *db, const char *zStart, const char *zEnd){ + int n; +#ifdef SQLITE_DEBUG + /* Because of the way the parser works, the span is guaranteed to contain + ** at least one non-space character */ + for(n=0; sqlite3Isspace(zStart[n]); n++){ assert( &zStart[n]<zEnd ); } +#endif + while( sqlite3Isspace(zStart[0]) ) zStart++; + n = (int)(zEnd - zStart); + while( sqlite3Isspace(zStart[n-1]) ) n--; + return sqlite3DbStrNDup(db, zStart, n); +} + +/* +** Free any prior content in *pz and replace it with a copy of zNew. +*/ +void sqlite3SetString(char **pz, sqlite3 *db, const char *zNew){ + char *z = sqlite3DbStrDup(db, zNew); + sqlite3DbFree(db, *pz); + *pz = z; +} + +/* +** Call this routine to record the fact that an OOM (out-of-memory) error +** has happened. This routine will set db->mallocFailed, and also +** temporarily disable the lookaside memory allocator and interrupt +** any running VDBEs. +** +** Always return a NULL pointer so that this routine can be invoked using +** +** return sqlite3OomFault(db); +** +** and thereby avoid unnecessary stack frame allocations for the overwhelmingly +** common case where no OOM occurs. +*/ +void *sqlite3OomFault(sqlite3 *db){ + if( db->mallocFailed==0 && db->bBenignMalloc==0 ){ + db->mallocFailed = 1; + if( db->nVdbeExec>0 ){ + AtomicStore(&db->u1.isInterrupted, 1); + } + DisableLookaside; + if( db->pParse ){ + Parse *pParse; + sqlite3ErrorMsg(db->pParse, "out of memory"); + db->pParse->rc = SQLITE_NOMEM_BKPT; + for(pParse=db->pParse->pOuterParse; pParse; pParse = pParse->pOuterParse){ + pParse->nErr++; + pParse->rc = SQLITE_NOMEM; + } + } + } + return 0; +} + +/* +** This routine reactivates the memory allocator and clears the +** db->mallocFailed flag as necessary. +** +** The memory allocator is not restarted if there are running +** VDBEs. +*/ +void sqlite3OomClear(sqlite3 *db){ + if( db->mallocFailed && db->nVdbeExec==0 ){ + db->mallocFailed = 0; + AtomicStore(&db->u1.isInterrupted, 0); + assert( db->lookaside.bDisable>0 ); + EnableLookaside; + } +} + +/* +** Take actions at the end of an API call to deal with error codes. +*/ +static SQLITE_NOINLINE int apiHandleError(sqlite3 *db, int rc){ + if( db->mallocFailed || rc==SQLITE_IOERR_NOMEM ){ + sqlite3OomClear(db); + sqlite3Error(db, SQLITE_NOMEM); + return SQLITE_NOMEM_BKPT; + } + return rc & db->errMask; +} + +/* +** This function must be called before exiting any API function (i.e. +** returning control to the user) that has called sqlite3_malloc or +** sqlite3_realloc. +** +** The returned value is normally a copy of the second argument to this +** function. However, if a malloc() failure has occurred since the previous +** invocation SQLITE_NOMEM is returned instead. +** +** If an OOM as occurred, then the connection error-code (the value +** returned by sqlite3_errcode()) is set to SQLITE_NOMEM. +*/ +int sqlite3ApiExit(sqlite3* db, int rc){ + /* If the db handle must hold the connection handle mutex here. + ** Otherwise the read (and possible write) of db->mallocFailed + ** is unsafe, as is the call to sqlite3Error(). + */ + assert( db!=0 ); + assert( sqlite3_mutex_held(db->mutex) ); + if( db->mallocFailed || rc ){ + return apiHandleError(db, rc); + } + return 0; +} |