SQLite

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains definitions of global variables and contants.
**
** $Id: global.c,v 1.2 2008/06/14 16:56:22 drh Exp $
*/
#include "sqliteInt.h"


/* An array to map all upper-case characters into their corresponding
** lower-case character. 
**

#endif
};

/*
** The following singleton contains the global configuration for
** the SQLite library.
*/
struct Sqlite3Config sqlite3Config = { 1, 1, 1, };

**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.444 2008/06/14 16:56:22 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

#ifdef SQLITE_ENABLE_FTS3
# include "fts3.h"
#endif

** Undo the effects of sqlite3_initialize().  Must not be called while
** there are outstanding database connections or memory allocations or
** while any part of SQLite is otherwise in use in any thread.  This
** routine is not threadsafe.  Not by a long shot.
*/
int sqlite3_shutdown(void){
  sqlite3_os_end();
  sqlite3MallocEnd();
  sqlite3_mutex_end();
  sqlite3FullInit = 0;
  sqlite3IsInit = 0;
  return SQLITE_OK;
}

/*

      /* Enable all mutexing */
      sqlite3Config.bCoreMutex = 1;
      sqlite3Config.bFullMutex = 1;
      break;
    }
    case SQLITE_CONFIG_MALLOC: {
      /* Specify an alternative malloc implementation */
      sqlite3Config.m = *va_arg(ap, sqlite3_mem_methods*);




      break;
    }
    case SQLITE_CONFIG_MEMSTATUS: {
      /* Enable or disable the malloc status collection */
      sqlite3Config.bMemstat = va_arg(ap, int);
      break;
    }
    default: {
      rc = SQLITE_ERROR;
      break;

/*
** 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.
**

** $Id: malloc.c,v 1.16 2008/06/14 16:56:22 drh Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>

/*
** This routine runs when the memory allocator sees that the

  nRet += sqlite3PagerReleaseMemory(n-nRet);
  return nRet;
#else
  return SQLITE_OK;
#endif
}

/*
** State information local to the memory allocation subsystem.
*/
static struct {
  sqlite3_mutex *mutex;         /* Mutex to serialize access */

  /*
  ** The alarm callback and its arguments.  The mem0.mutex lock will
  ** be held while the callback is running.  Recursive calls into
  ** the memory subsystem are allowed, but no new callbacks will be
  ** issued.  The alarmBusy variable is set to prevent recursive
  ** callbacks.
  */
  sqlite3_int64 alarmThreshold;
  void (*alarmCallback)(void*, sqlite3_int64,int);
  void *alarmArg;
  int alarmBusy;

  /*
  ** Performance statistics
  */
  sqlite3_int64 nowUsed;  /* Main memory currently in use */
  sqlite3_int64 mxUsed;   /* Highwater mark for nowUsed */
  int mxReq;              /* maximum request size for main or page-cache mem */
} mem0;

/*
** Initialize the memory allocation subsystem.
*/
int sqlite3MallocInit(void){
  if( sqlite3Config.m.xMalloc==0 ){
    sqlite3MemSetDefault();
  }
  memset(&mem0, 0, sizeof(mem0));
  if( sqlite3Config.bMemstat && sqlite3Config.bCoreMutex ){
    mem0.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM);
  }
  return sqlite3Config.m.xInit(sqlite3Config.m.pAppData);
}

/*
** Deinitialize the memory allocation subsystem.
*/
void sqlite3MallocEnd(void){
   sqlite3Config.m.xShutdown(sqlite3Config.m.pAppData);
}

/*
** Return the amount of memory currently checked out.
*/
sqlite3_int64 sqlite3_memory_used(void){
  sqlite3_int64 n;
  sqlite3_mutex_enter(mem0.mutex);
  n = mem0.nowUsed;
  sqlite3_mutex_leave(mem0.mutex);  
  return n;
}

/*
** 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;
  sqlite3_mutex_enter(mem0.mutex);
  n = mem0.mxUsed;
  if( resetFlag ){
    mem0.mxUsed = mem0.nowUsed;
  }
  sqlite3_mutex_leave(mem0.mutex);  
  return n;
}

/*
** Change the alarm callback
*/
int sqlite3_memory_alarm(
  void(*xCallback)(void *pArg, sqlite3_int64 used,int N),
  void *pArg,
  sqlite3_int64 iThreshold
){
  sqlite3_mutex_enter(mem0.mutex);
  mem0.alarmCallback = xCallback;
  mem0.alarmArg = pArg;
  mem0.alarmThreshold = iThreshold;
  sqlite3_mutex_leave(mem0.mutex);
  return SQLITE_OK;
}

/*
** Trigger the alarm 
*/
static void sqlite3MallocAlarm(int nByte){
  void (*xCallback)(void*,sqlite3_int64,int);
  sqlite3_int64 nowUsed;
  void *pArg;
  if( mem0.alarmCallback==0 || mem0.alarmBusy  ) return;
  mem0.alarmBusy = 1;
  xCallback = mem0.alarmCallback;
  nowUsed = mem0.nowUsed;
  pArg = mem0.alarmArg;
  sqlite3_mutex_leave(mem0.mutex);
  xCallback(pArg, nowUsed, nByte);
  sqlite3_mutex_enter(mem0.mutex);
  mem0.alarmBusy = 0;
}


/*
** Allocate memory.  This routine is like sqlite3_malloc() except that it
** assumes the memory subsystem has already been initialized.
*/
void *sqlite3Malloc(int n){
  void *p;
  int nFull;
  if( n<=0 ){
    return 0;
  }else if( sqlite3Config.bMemstat ){
    nFull = sqlite3Config.m.xRoundup(n);
    sqlite3_mutex_enter(mem0.mutex);
    if( n>mem0.mxReq ) mem0.mxReq = n;
    if( mem0.alarmCallback!=0 && mem0.nowUsed+nFull>=mem0.alarmThreshold ){
      sqlite3MallocAlarm(nFull);
    }
    if( sqlite3FaultStep(SQLITE_FAULTINJECTOR_MALLOC) ){
      p = 0;
    }else{
      p = sqlite3Config.m.xMalloc(nFull);
      if( p==0 ){
        sqlite3MallocAlarm(nFull);
        p = malloc(nFull);
      }
    }
    if( p ){
      mem0.nowUsed += nFull;
      if( mem0.nowUsed>mem0.mxUsed ){
        mem0.mxUsed = mem0.nowUsed;
      }
    }
    sqlite3_mutex_leave(mem0.mutex);
  }else{
    p = sqlite3Config.m.xMalloc(n);
  }
  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 sqlite3Malloc(n);
}

/*
** Return the size of a memory allocation previously obtained from
** sqlite3Malloc() or sqlite3_malloc().
*/
int sqlite3MallocSize(void *p){
  return sqlite3Config.m.xSize(p);
}

/*
** Free memory previously obtained from sqlite3Malloc().
*/
void sqlite3_free(void *p){
  if( p==0 ) return;
  if( sqlite3Config.bMemstat ){
    sqlite3_mutex_enter(mem0.mutex);
    mem0.nowUsed -= sqlite3MallocSize(p);
    sqlite3Config.m.xFree(p);
    sqlite3_mutex_leave(mem0.mutex);
  }else{
    sqlite3Config.m.xFree(p);
  }
}

/*
** Change the size of an existing memory allocation
*/
void *sqlite3Realloc(void *pOld, int nBytes){
  int nOld, nNew;
  void *pNew;
  if( pOld==0 ){
    return sqlite3Malloc(nBytes);
  }
  if( nBytes<=0 ){
    sqlite3_free(pOld);
    return 0;
  }
  nOld = sqlite3MallocSize(pOld);
  if( sqlite3Config.bMemstat ){
    sqlite3_mutex_enter(mem0.mutex);
    if( nBytes>mem0.mxReq ) mem0.mxReq = nBytes;
    nNew = sqlite3Config.m.xRoundup(nBytes);
    if( nOld==nNew ){
      pNew = pOld;
    }else{
      if( mem0.nowUsed+nNew-nOld>=mem0.alarmThreshold ){
        sqlite3MallocAlarm(nNew-nOld);
      }
      if( sqlite3FaultStep(SQLITE_FAULTINJECTOR_MALLOC) ){
        pNew = 0;
      }else{
        pNew = sqlite3Config.m.xRealloc(pOld, nNew);
        if( pNew==0 ){
          sqlite3MallocAlarm(nBytes);
          pNew = sqlite3Config.m.xRealloc(pOld, nNew);
        }
      }
      if( pNew ){
        mem0.nowUsed += nNew-nOld;
        if( mem0.nowUsed>mem0.mxUsed ){
          mem0.mxUsed = mem0.nowUsed;
        }
      }
    }
    sqlite3_mutex_leave(mem0.mutex);
  }else{
    pNew = sqlite3Config.m.xRealloc(pOld, nBytes);
  }
  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
  return sqlite3Realloc(pOld, n);
}


/*
** Allocate and zero memory.
*/ 
void *sqlite3MallocZero(int n){
  void *p = sqlite3Malloc(n);
  if( p ){
    memset(p, 0, n);
  }
  return p;
}

/*
** Allocate and zero memory.  If the allocation fails, make
** the mallocFailed flag in the connection pointer.
*/
void *sqlite3DbMallocZero(sqlite3 *db, int n){
  void *p = sqlite3DbMallocRaw(db, n);
  if( p ){
    memset(p, 0, n);
  }
  return p;
}

/*
** Allocate and zero memory.  If the allocation fails, make
** the mallocFailed flag in the connection pointer.
*/
void *sqlite3DbMallocRaw(sqlite3 *db, int n){
  void *p = 0;
  if( !db || db->mallocFailed==0 ){
    p = sqlite3Malloc(n);
    if( !p && db ){
      db->mallocFailed = 1;
    }
  }
  return p;
}

/*
** 2007 August 14
**
** 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.
**
*************************************************************************
**
** This file contains low-level memory allocation drivers for when
** SQLite will use the standard C-library malloc/realloc/free interface
** to obtain the memory it needs.
**
** This file contains implementations of the low-level memory allocation
** routines specified in the sqlite3_mem_methods object.
**
** $Id: mem1.c,v 1.19 2008/06/14 16:56:22 drh Exp $
*/
#include "sqliteInt.h"

/*
** This version of the memory allocator is the default.  It is
** used when no other memory allocator is specified using compile-time
** macros.
*/
#ifdef SQLITE_SYSTEM_MALLOC

/*
** Like malloc(), but remember the size of the allocation
** so that we can find it later using sqlite3MemSize().


**




** For this low-level routine, we are guaranteed that nByte>0 because
** cases of nByte<=0 will be intercepted and dealt with by higher level

** routines.
*/
static void *sqlite3MemMalloc(int nByte){
  sqlite3_int64 *p;



  assert( nByte>0 );




  nByte = (nByte+7)&~7;

  p = malloc( nByte+8 );

  p[0] = nByte;

  return (void*)&p[1];
}


/*
** Like free() but works for allocations obtained from sqlite3MemMalloc()
** or sqlite3MemRealloc().
**

** For this low-level routine, we already know that pPrior!=0 since
** cases where pPrior==0 will have been intecepted and dealt with



** by higher-level routines.


*/

static void sqlite3MemFree(void *pPrior){





  assert( pPrior!=0 );






  sqlite3_int64 *p = (sqlite3_int64*)pPrior;


  p--;
  free(p);

}






































/*
** Like realloc().  Resize an allocation previously obtained from
** sqlite3MemMalloc().
**
** For this low-level interface, we know that pPrior!=0.  Cases where
** pPrior==0 while have been intercepted by higher-level routine and
** redirected to xMalloc.  Similarly, we know that nByte>0 becauses
** cases where nByte<=0 will have been intercepted by higher-level
** routines and redirected to xFree.
*/
static void *sqlite3MemRealloc(void *pPrior, int nByte){
  sqlite3_int64 *p = (sqlite3_int64*)pPrior;
  assert( pPrior!=0 && nByte>0 );


  nByte = (nByte+7)&~7;


  p = (sqlite3_int64*)pPrior;


  p--;

  p = realloc(p, nByte+8 );


  if( p ){
    p[0] = nByte;
    p++;






  }
  return (void*)p;
}

/*
** Report the allocated size of a prior return from xMalloc()
** or xRealloc().
*/
static int sqlite3MemSize(void *pPrior){
  sqlite3_int64 *p;

  if( pPrior==0 ) return 0;



  p = (sqlite3_int64*)pPrior;
  p--;



  return p[0];

}

/*

** Round up a request size to the next valid allocation size.
*/
static int sqlite3MemRoundup(int n){



  return (n+7) & ~7;
}

/*
** Initialize this module.
*/
static int sqlite3MemInit(void *NotUsed){
  return SQLITE_OK;
}











/*
** Deinitialize this module.
*/
static void sqlite3MemShutdown(void *NotUsed){
  return;
}








/*
** 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.
*/
void sqlite3MemSetDefault(void){
  static const sqlite3_mem_methods defaultMethods = {

     sqlite3MemMalloc,

     sqlite3MemFree,


     sqlite3MemRealloc,



     sqlite3MemSize,



     sqlite3MemRoundup,
     sqlite3MemInit,
     sqlite3MemShutdown,
     0
  };

  sqlite3_config(SQLITE_CONFIG_MALLOC, &defaultMethods);

}

#endif /* SQLITE_SYSTEM_MALLOC */

/*
** 2007 August 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.
**
*************************************************************************
**
** This file contains low-level memory allocation drivers for when
** SQLite will use the standard C-library malloc/realloc/free interface
** to obtain the memory it needs while adding lots of additional debugging
** information to each allocation in order to help detect and fix memory
** leaks and memory usage errors.
**
** This file contains implementations of the low-level memory allocation
** routines specified in the sqlite3_mem_methods object.
**
** $Id: mem2.c,v 1.28 2008/06/14 16:56:22 drh Exp $
*/
#include "sqliteInt.h"

/*
** This version of the memory allocator is used only if the
** SQLITE_MEMDEBUG macro is defined
*/

/*
** All of the static variables used by this module are collected
** into a single structure named "mem".  This is to keep the
** static variables organized and to reduce namespace pollution
** when this module is combined with other in the amalgamation.
*/
static struct {











  
  /*
  ** Mutex to control access to the memory allocation subsystem.
  */
  sqlite3_mutex *mutex;







  /*
  ** Head and tail of a linked list of all outstanding allocations
  */
  struct MemBlockHdr *pFirst;
  struct MemBlockHdr *pLast;
  
  /*

  ** bytes.  i==NCSIZE is the number of allocation attempts for
  ** sizes more than NCSIZE*8 bytes.
  */
  int sizeCnt[NCSIZE];

} mem;









































































/*
** Given an allocation, find the MemBlockHdr for that allocation.
**
** This routine checks the guards at either end of the allocation and
** if they are incorrect it asserts.
*/
static struct MemBlockHdr *sqlite3MemsysGetHeader(void *pAllocation){

  assert( (nReserve-2)<=p->iSize || pU8[nReserve-3]==0x65 );
  return p;
}

/*
** Return the number of bytes currently allocated at address p.
*/
static int sqlite3MemSize(void *p){
  struct MemBlockHdr *pHdr;
  if( !p ){
    return 0;
  }
  pHdr = sqlite3MemsysGetHeader(p);
  return pHdr->iSize;
}

/*
** Initialize the memory allocation subsystem.
*/
static int sqlite3MemInit(void *NotUsed){
  mem.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
  return SQLITE_OK;
}

/*
** Deinitialize the memory allocation subsystem.
*/
static void sqlite3MemShutdown(void *NotUsed){
  sqlite3_mutex_free(mem.mutex);
  mem.mutex = 0;
}

/*
** Round up a request size to the next valid allocation size.
*/
static int sqlite3MemRoundup(int n){
  return (n+7) & ~7;
}

/*
** Allocate nByte bytes of memory.
*/
static void *sqlite3MemMalloc(int nByte){
  struct MemBlockHdr *pHdr;
  void **pBt;
  char *z;
  int *pInt;
  void *p = 0;
  int totalSize;


  int nReserve;
  sqlite3_mutex_enter(mem.mutex);
  assert( mem.disallow==0 );



  nReserve = (nByte+7)&~7;
  if( nReserve/8>NCSIZE-1 ){
    mem.sizeCnt[NCSIZE-1]++;
  }else{
    mem.sizeCnt[nReserve/8]++;
  }
  totalSize = nReserve + sizeof(*pHdr) + sizeof(int) +
               mem.nBacktrace*sizeof(void*) + mem.nTitle;



  p = malloc(totalSize);





  if( p ){
    z = p;
    pBt = (void**)&z[mem.nTitle];
    pHdr = (struct MemBlockHdr*)&pBt[mem.nBacktrace];
    pHdr->pNext = 0;
    pHdr->pPrev = mem.pLast;
    if( mem.pLast ){
      mem.pLast->pNext = pHdr;
    }else{
      mem.pFirst = pHdr;
    }
    mem.pLast = pHdr;
    pHdr->iForeGuard = FOREGUARD;
    pHdr->nBacktraceSlots = mem.nBacktrace;
    pHdr->nTitle = mem.nTitle;
    if( mem.nBacktrace ){
      void *aAddr[40];
      pHdr->nBacktrace = backtrace(aAddr, mem.nBacktrace+1)-1;
      memcpy(pBt, &aAddr[1], pHdr->nBacktrace*sizeof(void*));
      if( mem.xBacktrace ){
        mem.xBacktrace(nByte, pHdr->nBacktrace-1, &aAddr[1]);
      }
    }else{
      pHdr->nBacktrace = 0;
    }
    if( mem.nTitle ){
      memcpy(z, mem.zTitle, mem.nTitle);
    }
    pHdr->iSize = nByte;
    pInt = (int*)&pHdr[1];
    pInt[nReserve/sizeof(int)] = REARGUARD;
    memset(pInt, 0x65, nReserve);




    p = (void*)pInt;
  }
  sqlite3_mutex_leave(mem.mutex);

  return p; 
}

/*
** Free memory.
*/
static void sqlite3MemFree(void *pPrior){
  struct MemBlockHdr *pHdr;
  void **pBt;
  char *z;



  assert( mem.mutex!=0 );
  pHdr = sqlite3MemsysGetHeader(pPrior);
  pBt = (void**)pHdr;
  pBt -= pHdr->nBacktraceSlots;
  sqlite3_mutex_enter(mem.mutex);

  if( pHdr->pPrev ){
    assert( pHdr->pPrev->pNext==pHdr );
    pHdr->pPrev->pNext = pHdr->pNext;
  }else{
    assert( mem.pFirst==pHdr );
    mem.pFirst = pHdr->pNext;
  }

**
** For this debugging implementation, we *always* make a copy of the
** allocation into a new place in memory.  In this way, if the 
** higher level code is using pointer to the old allocation, it is 
** much more likely to break and we are much more liking to find
** the error.
*/
static void *sqlite3MemRealloc(void *pPrior, int nByte){
  struct MemBlockHdr *pOldHdr;
  void *pNew;







  assert( mem.disallow==0 );
  pOldHdr = sqlite3MemsysGetHeader(pPrior);
  pNew = sqlite3MemMalloc(nByte);
  if( pNew ){
    memcpy(pNew, pPrior, nByte<pOldHdr->iSize ? nByte : pOldHdr->iSize);
    if( nByte>pOldHdr->iSize ){
      memset(&((char*)pNew)[pOldHdr->iSize], 0x2b, nByte - pOldHdr->iSize);
    }
    sqlite3MemFree(pPrior);
  }
  return pNew;
}


/*
** Populate the low-level memory allocation function pointers in
** sqlite3Config.m with pointers to the routines in this file.
*/
void sqlite3MemSetDefault(void){
  static const sqlite3_mem_methods defaultMethods = {
     sqlite3MemMalloc,
     sqlite3MemFree,
     sqlite3MemRealloc,
     sqlite3MemSize,
     sqlite3MemRoundup,
     sqlite3MemInit,
     sqlite3MemShutdown,
     0
  };
  sqlite3_config(SQLITE_CONFIG_MALLOC, &defaultMethods);
}

/*
** Set the number of backtrace levels kept for each allocation.
** A value of zero turns of backtracing.  The number is always rounded
** up to a multiple of 2.
*/
void sqlite3MemdebugBacktrace(int depth){
  if( depth<0 ){ depth = 0; }

}

/*
** Set the title string for subsequent allocations.
*/
void sqlite3MemdebugSettitle(const char *zTitle){
  int n = strlen(zTitle) + 1;
  sqlite3_mutex_enter(mem.mutex);
  if( n>=sizeof(mem.zTitle) ) n = sizeof(mem.zTitle)-1;
  memcpy(mem.zTitle, zTitle, n);
  mem.zTitle[n] = 0;
  mem.nTitle = (n+7)&~7;
  sqlite3_mutex_leave(mem.mutex);
}

  if( mem.sizeCnt[NCSIZE-1] ){
    fprintf(out, "  >%3d: %d\n", NCSIZE*8, mem.sizeCnt[NCSIZE-1]);
  }
  fclose(out);
}

/*
** Return the number of times sqlite3MemMalloc() has been called.
*/
int sqlite3MemdebugMallocCount(){
  int i;
  int nTotal = 0;
  for(i=0; i<NCSIZE; i++){
    nTotal += mem.sizeCnt[i];
  }
  return nTotal;
}


#endif /* SQLITE_MEMDEBUG */

** exclusion and is thus suitable for use only in applications
** that use SQLite in a single thread.  But this implementation
** does do a lot of error checking on mutexes to make sure they
** are called correctly and at appropriate times.  Hence, this
** implementation is suitable for testing.
** debugging purposes
**
** $Id: mutex.c,v 1.19 2008/06/14 16:56:23 drh Exp $
*/
#include "sqliteInt.h"

#ifdef SQLITE_MUTEX_NOOP_DEBUG
/*
** In this implementation, mutexes do not provide any mutual exclusion.
** But the error checking is provided.  This implementation is useful

  return pNew;
}

/*
** This routine deallocates a previously allocated mutex.
*/
void sqlite3_mutex_free(sqlite3_mutex *p){
  if( p==0 ) return;
  assert( p->cnt==0 );
  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
  sqlite3_free(p);
}

/*
** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
** to enter a mutex.  If another thread is already within the mutex,
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK
** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can
** be entered multiple times by the same thread.  In such cases the,
** mutex must be exited an equal number of times before another thread
** can enter.  If the same thread tries to enter any other kind of mutex
** more than once, the behavior is undefined.
*/
void sqlite3_mutex_enter(sqlite3_mutex *p){
  if( p ){
    assert( p->id==SQLITE_MUTEX_RECURSIVE || sqlite3_mutex_notheld(p) );
    p->cnt++;
  }
}
int sqlite3_mutex_try(sqlite3_mutex *p){
  if( p ){
    assert( p->id==SQLITE_MUTEX_RECURSIVE || sqlite3_mutex_notheld(p) );
    p->cnt++;
  }
  return SQLITE_OK;
}

/*
** The sqlite3_mutex_leave() routine exits a mutex that was
** previously entered by the same thread.  The behavior
** is undefined if the mutex is not currently entered or
** is not currently allocated.  SQLite will never do either.
*/
void sqlite3_mutex_leave(sqlite3_mutex *p){
  if( p ){
    assert( sqlite3_mutex_held(p) );
    p->cnt--;
    assert( p->id==SQLITE_MUTEX_RECURSIVE || sqlite3_mutex_notheld(p) );
  }
}

/*
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
** intended for use inside assert() statements.
*/
int sqlite3_mutex_held(sqlite3_mutex *p){
  return p==0 || p->cnt>0;
}
int sqlite3_mutex_notheld(sqlite3_mutex *p){
  return p==0 || p->cnt==0;
}
#endif /* SQLITE_MUTEX_NOOP_DEBUG */

** on how SQLite interfaces are suppose to operate.
**
** The name of this file under configuration management is "sqlite.h.in".
** The makefile makes some minor changes to this file (such as inserting
** the version number) and changes its name to "sqlite3.h" as
** part of the build process.
**
** @(#) $Id: sqlite.h.in,v 1.327 2008/06/14 16:56:23 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.

**
** When a configuration option is set, sqlite3_config() returns SQLITE_OK.
** If the option is unknown or SQLite is unable to set the option 
** then this routine returns a non-zero [error code].
*/
int sqlite3_config(int, ...);

/*
** CAPI3REF: Memory Allocation Routines {F10155}
**
** An instance of this object defines the interface between SQLite
** and low-level memory allocation routines.  
**
** This object is used in only one place in the SQLite interface.
** A pointer to an instance of this object is the argument to
** [sqlite3_config] when the configuration option is
** [SQLITE_CONFIG_MALLOC].  By creating an instance of this object
** and passing it to [sqlite3_config] during configuration, an
** application can specify an alternative memory allocation subsystem
** for SQLite to use for all of its dynamic memory needs.
**
** Note that SQLite comes with a built-in memory allocator that is
** perfectly adequate for the overwhelming majority of applications
** and that this object is only useful to a tiny minority of applications
** with specialized memory allocation requirements.  This object is
** also used during testing of SQLite in order to specify an alternative
** memory allocator that simulates memory out-of-memory conditions in
** order to verify that SQLite recovers gracefully from such
** conditions.
**
** The xMalloc, xFree, and xRealloc methods should work like the
** malloc(), free(), and realloc() functions from the standard library.
**
** xSize should return the allocated size of a memory allocation
** previously obtained from xMalloc or xRealloc.  The allocated size
** is always at least as big as the requested size but may be larger.
**
** The xRoundup method returns what would be the allocated size of
** a memory allocation given a particular requested size.  Most memory
** allocators round up memory allocations at least to the next multiple
** of 8.  Some round up to a larger multiple or to a power of 2. 
**
** The xInit method initializes the memory allocator.  (For example,
** it might allocate any require mutexes or initialize internal data
** structures.  The xShutdown method is invoked (indirectly) by
** [sqlite3_shutdown()] and should deallocate any resources acquired
** by xInit.  The pAppData pointer is used as the only parameter to
** xInit and xShutdown.
*/
typedef struct sqlite3_mem_methods sqlite3_mem_methods;
struct sqlite3_mem_methods {
  void *(*xMalloc)(int);         /* Memory allocation function */
  void (*xFree)(void*);          /* Free a prior allocation */
  void *(*xRealloc)(void*,int);  /* Resize an allocation */
  int (*xSize)(void*);           /* Return the size of an allocation */
  int (*xRoundup)(int);          /* Round up request size to allocation size */
  int (*xInit)(void*);           /* Initialize the memory allocator */
  void (*xShutdown)(void*);      /* Deinitialize the memory allocator */
  void *pAppData;                /* Argument to xInit() and xShutdown() */
};

/*
** CAPI3REF: Configuration Options {F10160}
**
** These constants are the available integer configuration options that
** can be passed as the first argument to the [sqlite3_config()] interface.
** 
** <dl>

** In this mode (which is the default when SQLite is compiled with
** SQLITE_THREADSAFE=1) the SQLite library will itself serialize access
** to [database connections] and [prepared statements] so that the
** application is free to use the same [database connection] or the
** same [prepared statement] in different threads at the same time.</dd>
**
** <dt>SQLITE_CONFIG_MALLOC</dt>
** <dd>This option takes a single argument which is a pointer to an



** instance of the [sqlite3_mem_methods] structure.  The argument specifics
** alternative low-level memory allocation routines to be used in place

** the memory allocation routines built into SQLite.</dd>
**
** <dt>SQLITE_CONFIG_MEMSTATUS</dt>
** <dd>This option takes single boolean argument which enables or disables
** the collection of memory allocation statistics.  When disabled, the
** following SQLite interfaces become non-operational:
**   <ul>
**   <li> [sqlite3_memory_used()]
**   <li> [sqlite3_memory_highwater()]
**   <li> [sqlite3_soft_heap_limit()]
**   <li> sqlite3_memory_status()
**   </ul>
** </dd>
** </dl>
*/ 
#define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
#define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
#define SQLITE_CONFIG_SERIALIZED    3  /* nil */
#define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */
#define SQLITE_CONFIG_MEMSTATUS     5  /* boolean */

/* These options are to be added later.  Currently unused and undocumented. */
#define SQLITE_CONFIG_HEAP          6  /* void*, int64, min, max, tmp */


/*
** CAPI3REF: Enable Or Disable Extended Result Codes {F12200}

/*
** 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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.709 2008/06/14 16:56:23 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Include the configuration header output by 'configure' if we're using the
** autoconf-based build

  int rc;             /* Result code stored here */
} InitData;

/*
** Structure containing global configuration data for the SQLite library.
*/
struct Sqlite3Config {
  int bMemstat;                     /* True to enable memory status */

  int bCoreMutex;                   /* True to enable core mutexing */
  int bFullMutex;                   /* True to enable full mutexing */
  sqlite3_mem_methods m;            /* Low-level memory allocation interface */
  void *pHeap;                      /* Heap storage space */
  sqlite3_int64 nHeap;              /* Size of pHeap[] */
  int mnReq, mxReq;                 /* Min and max memory request sizes */
  int nTemp;                        /* Part of pHeap for temporary allos */



};

/*
** Assuming zIn points to the first byte of a UTF-8 character,
** advance zIn to point to the first byte of the next UTF-8 character.
*/
#define SQLITE_SKIP_UTF8(zIn) {                        \

** Internal function prototypes
*/
int sqlite3StrICmp(const char *, const char *);
int sqlite3StrNICmp(const char *, const char *, int);
int sqlite3IsNumber(const char*, int*, u8);

int sqlite3MallocInit(void);
void sqlite3MallocEnd(void);
void *sqlite3Malloc(int);
void *sqlite3MallocZero(int);
void *sqlite3DbMallocZero(sqlite3*, int);
void *sqlite3DbMallocRaw(sqlite3*, int);
char *sqlite3StrDup(const char*);
char *sqlite3StrNDup(const char*, int);
char *sqlite3DbStrDup(sqlite3*,const char*);
char *sqlite3DbStrNDup(sqlite3*,const char*, int);
void *sqlite3Realloc(void*, int);
void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
void *sqlite3DbRealloc(sqlite3 *, void *, int);
int sqlite3MallocSize(void *);
void sqlite3MemSetDefault(void);

int sqlite3IsNaN(double);

char *sqlite3MPrintf(sqlite3*,const char*, ...);
char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
  void sqlite3DebugPrintf(const char*, ...);