SQLite

/*
** Register a statically linked extension that is automatically
** loaded by every new database connection.
*/
int sqlite3_auto_extension(void *xInit){
  int i;
  int rc = SQLITE_OK;
  sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_GLOBAL);
  sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
  sqlite3_mutex_enter(mutex);
  for(i=0; i<nAutoExtension; i++){
    if( aAutoExtension[i]==xInit ) break;
  }
  if( i==nAutoExtension ){
    int nByte = (++nAutoExtension)*sizeof(aAutoExtension[0]);
    aAutoExtension = sqlite3_realloc(aAutoExtension, nByte);

  return rc;
}

/*
** Reset the automatic extension loading mechanism.
*/
void sqlite3_reset_auto_extension(void){
  sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_GLOBAL);
  sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
  sqlite3_mutex_enter(mutex);
  sqlite3_free(aAutoExtension);
  aAutoExtension = 0;
  nAutoExtension = 0;
  sqlite3_mutex_leave(mutex);
}

  if( nAutoExtension==0 ){
    /* Common case: early out without every having to acquire a mutex */
    return SQLITE_OK;
  }
  for(i=0; go; i++){
    char *zErrmsg = 0;
    sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_GLOBAL);
    sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
    sqlite3_mutex_enter(mutex);
    if( i>=nAutoExtension ){
      xInit = 0;
      go = 0;
    }else{
      xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*))
              aAutoExtension[i];

} sqlite3LockingStyle;
#endif /* SQLITE_ENABLE_LOCKING_STYLE */

/*
** Helper functions to obtain and relinquish the global mutex.
*/
static void enterMutex(){
  sqlite3_mutex_enter(sqlite3_mutex_alloc(SQLITE_MUTEX_GLOBAL));
  sqlite3_mutex_enter(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER));
}
static void leaveMutex(){
  sqlite3_mutex_leave(sqlite3_mutex_alloc(SQLITE_MUTEX_GLOBAL));
  sqlite3_mutex_leave(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER));
}

#if SQLITE_THREADSAFE
/*
** This variable records whether or not threads can override each others
** locks.
**

*************************************************************************
** This file contains code to implement a pseudo-random number
** generator (PRNG) for SQLite.
**
** Random numbers are used by some of the database backends in order
** to generate random integer keys for tables or random filenames.
**
** $Id: random.c,v 1.19 2007/08/21 10:44:16 drh Exp $
** $Id: random.c,v 1.20 2007/08/21 13:51:23 drh Exp $
*/
#include "sqliteInt.h"


/*
** Get a single 8-bit random value from the RC4 PRNG.  The Mutex
** must be held while executing this routine.

}

/*
** Return N random bytes.
*/
void sqlite3Randomness(int N, void *pBuf){
  unsigned char *zBuf = pBuf;
  static sqlite3_mutex *mutex = 0;
  if( mutex==0 ){
    mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_PRNG);
  }
  sqlite3_mutex_enter(sqlite3_mutex_alloc(SQLITE_MUTEX_PRNG));
  sqlite3_mutex_enter(mutex);
  while( N-- ){
    *(zBuf++) = randomByte();
  }
  sqlite3_mutex_leave(sqlite3_mutex_alloc(SQLITE_MUTEX_PRNG));
  sqlite3_mutex_leave(mutex);
}

/*
** 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 1.593 2007/08/20 22:48:43 drh Exp $
** @(#) $Id: sqliteInt.h,v 1.594 2007/08/21 13:51:23 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_
#include "sqliteLimit.h"


#if defined(SQLITE_TCL) || defined(TCLSH)

typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
typedef INT16_TYPE i16;            /* 2-byte signed integer */
typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
typedef UINT8_TYPE i8;             /* 1-byte signed integer */

/*
** The mutex subsystem provides a handfull of static mutexes
** that are identified by small positive integers.  The following
** macros give symbolic names to those integers.
*/
#define SQLITE_MUTEX_MEM      1    /* Used by the memory allocator */
#define SQLITE_MUTEX_PRNG     2    /* Used by pseudorandom generator */
#define SQLITE_MUTEX_GLOBAL   3    /* Used by global variables */
#define SQLITE_MUTEX_STATIC_MAX 3

/*
** Macros to determine whether the machine is big or little endian,
** evaluated at runtime.
*/
extern const int sqlite3one;
#if defined(i386) || defined(__i386__) || defined(_M_IX86)
# define SQLITE_BIGENDIAN    0