** Enable or disable the shared pager and schema features.
**
** This routine has no effect on existing database connections.
** The shared cache setting effects only future calls to
** sqlite3_open(), sqlite3_open16(), or sqlite3_open_v2().
*/
int sqlite3_enable_shared_cache(int enable){





  sqlite3GlobalConfig.sharedCacheEnabled = enable;
  return SQLITE_OK;

}
#endif



#ifdef SQLITE_OMIT_SHARED_CACHE
  /*
................................................................................
    */
    if( page1[19]==2 && pBt->doNotUseWAL==0 ){
      int isOpen = 0;
      rc = sqlite3PagerOpenWal(pBt->pPager, &isOpen);
      if( rc!=SQLITE_OK ){
        goto page1_init_failed;
      }else if( isOpen==0 ){












        releasePage(pPage1);
        return SQLITE_OK;
      }
      rc = SQLITE_NOTADB;
    }
#endif

** Enable or disable the shared pager and schema features.
**
** This routine has no effect on existing database connections.
** The shared cache setting effects only future calls to
** sqlite3_open(), sqlite3_open16(), or sqlite3_open_v2().
*/
int sqlite3_enable_shared_cache(int enable){
#if defined(__APPLE__) && !defined(SQLITE_TEST) && !defined(TH3_COMPATIBILITY)
  /* Enable global shared cache function for debugging and unit tests, 
  ** but not for release */
  return SQLITE_MISUSE;
#else
  sqlite3GlobalConfig.sharedCacheEnabled = enable;
  return SQLITE_OK;
#endif
}
#endif



#ifdef SQLITE_OMIT_SHARED_CACHE
  /*
................................................................................
    */
    if( page1[19]==2 && pBt->doNotUseWAL==0 ){
      int isOpen = 0;
      rc = sqlite3PagerOpenWal(pBt->pPager, &isOpen);
      if( rc!=SQLITE_OK ){
        goto page1_init_failed;
      }else if( isOpen==0 ){
#ifdef SQLITE_DEFAULT_WAL_SAFETYLEVEL
        /* Default to specified safety_level for WAL mode */
        if( pBt->db!=0 && pBt->db->aDb!=0 ){
          sqlite3 *db = pBt->db;
          if( db->aDb[0].safety_level != SQLITE_DEFAULT_WAL_SAFETYLEVEL) {
            db->aDb[0].safety_level = SQLITE_DEFAULT_WAL_SAFETYLEVEL;
            sqlite3PagerSetSafetyLevel(pBt->pPager, SQLITE_DEFAULT_WAL_SAFETYLEVEL, 
                                       (db->flags&SQLITE_FullFSync)!=0,
                                       (db->flags&SQLITE_CkptFullFSync)!=0);
          }
        }
#endif
        releasePage(pPage1);
        return SQLITE_OK;
      }
      rc = SQLITE_NOTADB;
    }
#endif

      newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
    }
    db->aLimit[limitId] = newLimit;
  }
  return oldLimit;                     /* IMP: R-53341-35419 */
}
#if defined(SQLITE_ENABLE_AUTO_PROFILE)


static void profile_sql(void *aux, const char *sql, u64 ns) {
#pragma unused(aux)
	fprintf(stderr, "Query: %s\n Execution Time: %llu ms\n", sql, ns / 1000000);



}
#endif

/*
** This function is used to parse both URIs and non-URI filenames passed by the
** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
** URIs specified as part of ATTACH statements.
................................................................................

  assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
  memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
  db->autoCommit = 1;
  db->nextAutovac = -1;
  db->nextPagesize = 0;
  db->flags |= SQLITE_ShortColNames | SQLITE_AutoIndex | SQLITE_EnableTrigger



#if SQLITE_DEFAULT_FILE_FORMAT<4
                 | SQLITE_LegacyFileFmt
#endif
#ifdef SQLITE_ENABLE_LOAD_EXTENSION
                 | SQLITE_LoadExtension
#endif
#if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
................................................................................
    db = 0;
  }else if( rc!=SQLITE_OK ){
    db->magic = SQLITE_MAGIC_SICK;
  }
#if defined(SQLITE_ENABLE_AUTO_PROFILE)
  if( db && !rc ){
    char *envprofile = getenv("SQLITE_AUTO_PROFILE");

    
    if( envprofile!=NULL ){
      sqlite3_profile(db, profile_sql, NULL);



    }
  }
#endif
  *ppDb = db;
#ifdef SQLITE_ENABLE_SQLRR
  SRRecOpen(db, zFilename, flags);
#endif
................................................................................
    int x = strcmp(zFilename, zParam);
    zFilename += sqlite3Strlen30(zFilename) + 1;
    if( x==0 ) return zFilename;
    zFilename += sqlite3Strlen30(zFilename) + 1;
  }
  return 0;
}

      newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
    }
    db->aLimit[limitId] = newLimit;
  }
  return oldLimit;                     /* IMP: R-53341-35419 */
}
#if defined(SQLITE_ENABLE_AUTO_PROFILE)
void _sqlite_auto_profile(void *aux, const char *sql, u64 ns);
void _sqlite_auto_trace(void *aux, const char *sql);
void _sqlite_auto_profile(void *aux, const char *sql, u64 ns) {
#pragma unused(aux)
	fprintf(stderr, "Query: %s\n Execution Time: %llu ms\n", sql, ns / 1000000);
}
void _sqlite_auto_trace(void *aux, const char *sql) {
	fprintf(stderr, "TraceSQL(%p): %s\n", aux, sql);
}
#endif

/*
** This function is used to parse both URIs and non-URI filenames passed by the
** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
** URIs specified as part of ATTACH statements.
................................................................................

  assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
  memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
  db->autoCommit = 1;
  db->nextAutovac = -1;
  db->nextPagesize = 0;
  db->flags |= SQLITE_ShortColNames | SQLITE_AutoIndex | SQLITE_EnableTrigger
#if SQLITE_DEFAULT_CKPTFULLFSYNC
                 | SQLITE_CkptFullFSync
#endif
#if SQLITE_DEFAULT_FILE_FORMAT<4
                 | SQLITE_LegacyFileFmt
#endif
#ifdef SQLITE_ENABLE_LOAD_EXTENSION
                 | SQLITE_LoadExtension
#endif
#if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
................................................................................
    db = 0;
  }else if( rc!=SQLITE_OK ){
    db->magic = SQLITE_MAGIC_SICK;
  }
#if defined(SQLITE_ENABLE_AUTO_PROFILE)
  if( db && !rc ){
    char *envprofile = getenv("SQLITE_AUTO_PROFILE");
    char *envtrace = getenv("SQLITE_AUTO_TRACE");
    
    if( envprofile!=NULL ){
      sqlite3_profile(db, _sqlite_auto_profile, db);
    }
    if( envtrace!=NULL ){
      sqlite3_trace(db, _sqlite_auto_trace, db);
    }
  }
#endif
  *ppDb = db;
#ifdef SQLITE_ENABLE_SQLRR
  SRRecOpen(db, zFilename, flags);
#endif
................................................................................
    int x = strcmp(zFilename, zParam);
    zFilename += sqlite3Strlen30(zFilename) + 1;
    if( x==0 ) return zFilename;
    zFilename += sqlite3Strlen30(zFilename) + 1;
  }
  return 0;
}

#if (SQLITE_ENABLE_APPLE_SPI>0)
#define SQLITE_FILE_HEADER_LEN 16
#include <fcntl.h>
#include "sqlite3_private.h"
#include "btreeInt.h"
#include <errno.h>
#include <sys/param.h>

/* Check for a conflicting lock.  If one is found, print an this
 ** on standard output using the format string given and return 1.
 ** If there are no conflicting locks, return 0.
 */
static int isLocked(
  pid_t pid,            /* PID to test for lock owner */
  int h,                /* File descriptor to check */
  int type,             /* F_RDLCK or F_WRLCK */
  unsigned int iOfst,   /* First byte of the lock */
  unsigned int iCnt,    /* Number of bytes in the lock range */
  const char *zType     /* Type of lock */
){
  struct flock lk;
  int err;
  
  memset(&lk, 0, sizeof(lk));
  lk.l_type = type;
  lk.l_whence = SEEK_SET;
  lk.l_start = iOfst;
  lk.l_len = iCnt;

  if( pid!=SQLITE_LOCKSTATE_ANYPID ){
#ifndef F_GETLKPID
# warning F_GETLKPID undefined, _sqlite3_lockstate falling back to F_GETLK
    err = fcntl(h, F_GETLK, &lk);
#else
    lk.l_pid = pid;
    err = fcntl(h, F_GETLKPID, &lk);
#endif
  }else{
    err = fcntl(h, F_GETLK, &lk);
  }

  if( err==(-1) ){
    fprintf(stderr, "fcntl(%d) failed: errno=%d\n", h, errno);
    return -1;
  }
  
  if( lk.l_type!=F_UNLCK && (pid==SQLITE_LOCKSTATE_ANYPID || lk.l_pid==pid) ){
#ifdef SQLITE_DEBUG
    fprintf(stderr, "%s lock held by %d\n", zType, (int)lk.l_pid);
#endif
    return 1;
  } 
  return 0;
}

/*
 ** Location of locking bytes in the database file
 */
#ifndef PENDING_BYTE
# define PENDING_BYTE      (0x40000000)
# define RESERVED_BYTE     (PENDING_BYTE+1)
# define SHARED_FIRST      (PENDING_BYTE+2)
# define SHARED_SIZE       510
#endif /* PENDING_BYTE */

/*
 ** Lock locations for shared-memory locks used by WAL mode.
 */
#ifndef SHM_BASE
# define SHM_BASE          120
# define SHM_WRITE         SHM_BASE
# define SHM_CHECKPOINT    (SHM_BASE+1)
# define SHM_RECOVER       (SHM_BASE+2)
# define SHM_READ_FIRST    (SHM_BASE+3)
# define SHM_READ_SIZE     5
#endif /* SHM_BASE */

/* 
** Testing a file path for sqlite locks held by a process ID. 
** Returns SQLITE_LOCKSTATE_ON if locks are present on path
** that would prevent writing to the database.
**
** This test only works for lock testing on unix/posix VFS.
** Adapted from tool/getlock.c f4c39b651370156cae979501a7b156bdba50e7ce
*/
int _sqlite3_lockstate(const char *path, pid_t pid){
  int hDb;        /* File descriptor for the open database file */
  int hShm;       /* File descriptor for WAL shared-memory file */
  ssize_t got;    /* Bytes read from header */
  int isWal;                 /* True if in WAL mode */
  int nLock = 0;             /* Number of locks held */
  unsigned char aHdr[100];   /* Database header */
  
  /* Open the file at path and make sure we are dealing with a database file */
  hDb = open(path, O_RDONLY | O_NOCTTY);
  if( hDb<0 ){
    return SQLITE_LOCKSTATE_ERROR;
  }
  assert( (strlen(SQLITE_FILE_HEADER)+1)==SQLITE_FILE_HEADER_LEN );
  got = pread(hDb, aHdr, 100, 0);
  if( got<0 ){
    close(hDb);
    return SQLITE_LOCKSTATE_ERROR;
  }
  if( got!=100 || memcmp(aHdr, SQLITE_FILE_HEADER, SQLITE_FILE_HEADER_LEN)!=0 ){
    close(hDb);
    return SQLITE_LOCKSTATE_NOTADB;
  }
  
  /* First check for an exclusive lock */
  nLock += isLocked(pid, hDb, F_RDLCK, SHARED_FIRST, SHARED_SIZE, "EXCLUSIVE");
  isWal = aHdr[18]==2;
  if( nLock==0 && isWal==0 ){
    /* Rollback mode */
    nLock += isLocked(pid, hDb, F_WRLCK, PENDING_BYTE, SHARED_SIZE+2, "PENDING|RESERVED|SHARED");
  }
  close(hDb);
  if( nLock==0 && isWal!=0 ){
    char zShm[MAXPATHLEN];
    
    close(hDb);
    /* WAL mode */
    strlcpy(zShm, path, MAXPATHLEN);
    strlcat(zShm, "-shm", MAXPATHLEN);
    hShm = open(zShm, O_RDONLY, 0);
    if( hShm<0 ){
      return SQLITE_LOCKSTATE_OFF;
    }
    if( isLocked(pid, hShm, F_RDLCK, SHM_RECOVER, 1, "WAL-RECOVERY") ||
       isLocked(pid, hShm, F_RDLCK, SHM_WRITE, 1, "WAL-WRITE") ){
      nLock = 1;
    }
    close(hShm);
  }
  if( nLock>0 ){
    return SQLITE_LOCKSTATE_ON;
  }
  return SQLITE_LOCKSTATE_OFF;
}

#endif /* SQLITE_ENABLE_APPLE_SPI */

  sqlite3_vfs *pVfs, 
  const char *zPath, 
  sqlite3_file *pFile, 
  int flags, 
  int *pFlagsOut
){
  int rc;

  DO_OS_MALLOC_TEST(0);
  /* 0x87f3f is a mask of SQLITE_OPEN_ flags that are valid to be passed
  ** down into the VFS layer.  Some SQLITE_OPEN_ flags (for example,
  ** SQLITE_OPEN_FULLMUTEX or SQLITE_OPEN_SHAREDCACHE) are blocked before
  ** reaching the VFS. */





  rc = pVfs->xOpen(pVfs, zPath, pFile, flags & 0x87f3f, pFlagsOut);
  assert( rc==SQLITE_OK || pFile->pMethods==0 );
  return rc;
}
int sqlite3OsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  return pVfs->xDelete(pVfs, zPath, dirSync);
}
int sqlite3OsAccess(

  sqlite3_vfs *pVfs, 
  const char *zPath, 
  sqlite3_file *pFile, 
  int flags, 
  int *pFlagsOut
){
  int rc;
  int openFlags;
  DO_OS_MALLOC_TEST(0);
  /* 0x87f3f is a mask of SQLITE_OPEN_ flags that are valid to be passed
  ** down into the VFS layer.  Some SQLITE_OPEN_ flags (for example,
  ** SQLITE_OPEN_FULLMUTEX or SQLITE_OPEN_SHAREDCACHE) are blocked before
  ** reaching the VFS. */
#if SQLITE_ENABLE_DATA_PROTECTION
  openFlags = flags & (0x87f3f | SQLITE_OPEN_FILEPROTECTION_MASK);
#else
  openFlags = flags & 0x87f3f;
#endif
  rc = pVfs->xOpen(pVfs, zPath, pFile, openFlags, pFlagsOut);
  assert( rc==SQLITE_OK || pFile->pMethods==0 );
  return rc;
}
int sqlite3OsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  return pVfs->xDelete(pVfs, zPath, dirSync);
}
int sqlite3OsAccess(

#include <errno.h>
#ifndef SQLITE_OMIT_WAL
#include <sys/mman.h>
#endif

#if SQLITE_ENABLE_LOCKING_STYLE
# include <sys/ioctl.h>





# if OS_VXWORKS
#  include <semaphore.h>
#  include <limits.h>
# else
#  include <sys/file.h>
#  include <sys/param.h>
# endif
................................................................................
  UnixUnusedFd *pUnused;              /* Pre-allocated UnixUnusedFd */
  const char *zPath;                  /* Name of the file */
  unixShm *pShm;                      /* Shared memory segment information */
  int szChunk;                        /* Configured by FCNTL_CHUNK_SIZE */
#if SQLITE_ENABLE_LOCKING_STYLE
  int openFlags;                      /* The flags specified at open() */
#endif



#if SQLITE_ENABLE_LOCKING_STYLE || defined(__APPLE__)
  unsigned fsFlags;                   /* cached details from statfs() */
#endif
#if OS_VXWORKS
  int isDelete;                       /* Delete on close if true */
  struct vxworksFileId *pId;          /* Unique file ID */
#endif
................................................................................
** testing and debugging only.
*/
#if SQLITE_THREADSAFE
#define threadid pthread_self()
#else
#define threadid 0
#endif
























































































































































































































































































/*
** Different Unix systems declare open() in different ways.  Same use
** open(const char*,int,mode_t).  Others use open(const char*,int,...).
** The difference is important when using a pointer to the function.
**
** The safest way to deal with the problem is to always use this wrapper
................................................................................
*/ 
static void closePendingFds(unixFile *pFile){
  unixInodeInfo *pInode = pFile->pInode;
  UnixUnusedFd *p;
  UnixUnusedFd *pNext;
  for(p=pInode->pUnused; p; p=pNext){
    pNext = p->pNext;










    robust_close(pFile, p->fd, __LINE__);
    sqlite3_free(p);

  }
  pInode->pUnused = 0;
}

/*
** Release a unixInodeInfo structure previously allocated by findInodeInfo().
**
................................................................................
  if( !reserved && !pFile->pInode->bProcessLock ){
    struct flock lock;
    lock.l_whence = SEEK_SET;
    lock.l_start = RESERVED_BYTE;
    lock.l_len = 1;
    lock.l_type = F_WRLCK;
    if( osFcntl(pFile->h, F_GETLK, &lock) ){





      rc = SQLITE_IOERR_CHECKRESERVEDLOCK;
      pFile->lastErrno = errno;

    } else if( lock.l_type!=F_UNLCK ){
      reserved = 1;
    }
  }
#endif
  
  unixLeaveMutex();
................................................................................
      || (eFileLock==EXCLUSIVE_LOCK && pFile->eFileLock<PENDING_LOCK)
  ){
    lock.l_type = (eFileLock==SHARED_LOCK?F_RDLCK:F_WRLCK);
    lock.l_start = PENDING_BYTE;
    if( unixFileLock(pFile, &lock) ){
      tErrno = errno;
      rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
      if( rc!=SQLITE_BUSY ){
        pFile->lastErrno = tErrno;
      }
      goto end_lock;
    }
  }


................................................................................
    /* Drop the temporary PENDING lock */
    lock.l_start = PENDING_BYTE;
    lock.l_len = 1L;
    lock.l_type = F_UNLCK;
    if( unixFileLock(pFile, &lock) && rc==SQLITE_OK ){
      /* This could happen with a network mount */
      tErrno = errno;



      rc = SQLITE_IOERR_UNLOCK; 

    }

    if( rc ){
      if( rc!=SQLITE_BUSY ){
        pFile->lastErrno = tErrno;
      }
      goto end_lock;
    }else{
      pFile->eFileLock = SHARED_LOCK;
      pInode->nLock++;
      pInode->nShared = 1;
................................................................................
        
        lock.l_type = F_UNLCK;
        lock.l_whence = SEEK_SET;
        lock.l_start = SHARED_FIRST;
        lock.l_len = divSize;
        if( unixFileLock(pFile, &lock)==(-1) ){
          tErrno = errno;



          rc = SQLITE_IOERR_UNLOCK;

          if( IS_LOCK_ERROR(rc) ){
            pFile->lastErrno = tErrno;
          }
          goto end_unlock;
        }
        lock.l_type = F_RDLCK;
        lock.l_whence = SEEK_SET;
................................................................................
        }
        lock.l_type = F_UNLCK;
        lock.l_whence = SEEK_SET;
        lock.l_start = SHARED_FIRST+divSize;
        lock.l_len = SHARED_SIZE-divSize;
        if( unixFileLock(pFile, &lock)==(-1) ){
          tErrno = errno;



          rc = SQLITE_IOERR_UNLOCK;

          if( IS_LOCK_ERROR(rc) ){
            pFile->lastErrno = tErrno;
          }
          goto end_unlock;
        }
      }else
#endif /* defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE */
      {
        lock.l_type = F_RDLCK;
        lock.l_whence = SEEK_SET;
        lock.l_start = SHARED_FIRST;
        lock.l_len = SHARED_SIZE;
        if( unixFileLock(pFile, &lock) ){







          /* In theory, the call to unixFileLock() cannot fail because another
          ** process is holding an incompatible lock. If it does, this 
          ** indicates that the other process is not following the locking
          ** protocol. If this happens, return SQLITE_IOERR_RDLOCK. Returning
          ** SQLITE_BUSY would confuse the upper layer (in practice it causes 
          ** an assert to fail). */ 
          rc = SQLITE_IOERR_RDLOCK;
          pFile->lastErrno = errno;

          goto end_unlock;
        }
      }
    }
    lock.l_type = F_UNLCK;
    lock.l_whence = SEEK_SET;
    lock.l_start = PENDING_BYTE;
    lock.l_len = 2L;  assert( PENDING_BYTE+1==RESERVED_BYTE );
    if( unixFileLock(pFile, &lock)==0 ){
      pInode->eFileLock = SHARED_LOCK;
    }else{







      rc = SQLITE_IOERR_UNLOCK;
      pFile->lastErrno = errno;

      goto end_unlock;
    }
  }
  if( eFileLock==NO_LOCK ){
    /* Decrement the shared lock counter.  Release the lock using an
    ** OS call only when all threads in this same process have released
    ** the lock.
................................................................................
      lock.l_start = lock.l_len = 0L;
      SimulateIOErrorBenign(1);
      SimulateIOError( h=(-1) )
      SimulateIOErrorBenign(0);
      if( unixFileLock(pFile, &lock)==0 ){
        pInode->eFileLock = NO_LOCK;
      }else{







        rc = SQLITE_IOERR_UNLOCK;
	pFile->lastErrno = errno;

        pInode->eFileLock = NO_LOCK;
        pFile->eFileLock = NO_LOCK;
      }
    }

    /* Decrement the count of locks against this same file.  When the
    ** count reaches zero, close any other file descriptors whose close
................................................................................
**
** It is *not* necessary to hold the mutex when this routine is called,
** even on VxWorks.  A mutex will be acquired on VxWorks by the
** vxworksReleaseFileId() routine.
*/
static int closeUnixFile(sqlite3_file *id){
  unixFile *pFile = (unixFile*)id;




















  if( pFile->dirfd>=0 ){
    robust_close(pFile, pFile->dirfd, __LINE__);
    pFile->dirfd=-1;
  }
  if( pFile->h>=0 ){
    robust_close(pFile, pFile->h, __LINE__);
    pFile->h = -1;
  }

#if OS_VXWORKS
  if( pFile->pId ){
    if( pFile->isDelete ){
      unlink(pFile->pId->zCanonicalName);
    }
    vxworksReleaseFileId(pFile->pId);
    pFile->pId = 0;
................................................................................
      rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
      if( IS_LOCK_ERROR(rc) ){
        pFile->lastErrno = tErrno;
      }
    }
    return rc;
  } 






  robust_close(pFile, fd, __LINE__);

  
  /* got it, set the type and return ok */
  pFile->eFileLock = eFileLock;
  return rc;
}

/*
................................................................................
  
  /* To fully unlock the database, delete the lock file */
  assert( eFileLock==NO_LOCK );
  if( unlink(zLockFile) ){
    int rc = 0;
    int tErrno = errno;
    if( ENOENT != tErrno ){



      rc = SQLITE_IOERR_UNLOCK;

    }
    if( IS_LOCK_ERROR(rc) ){
      pFile->lastErrno = tErrno;
    }
    return rc; 
  }
  pFile->eFileLock = NO_LOCK;
................................................................................
    int lrc = robust_flock(pFile->h, LOCK_EX | LOCK_NB);
    if( !lrc ){
      /* got the lock, unlock it */
      lrc = robust_flock(pFile->h, LOCK_UN);
      if ( lrc ) {
        int tErrno = errno;
        /* unlock failed with an error */



        lrc = SQLITE_IOERR_UNLOCK; 

        if( IS_LOCK_ERROR(lrc) ){
          pFile->lastErrno = tErrno;
          rc = lrc;
        }
      }
    } else {
      int tErrno = errno;
................................................................................
       ** A failed directory sync is not a big deal.  So it seems
       ** better to ignore the error.  Ticket #1657
       */
       /* pFile->lastErrno = errno; */
       /* return SQLITE_IOERR; */
    }
#endif
    /* Only need to sync once, so close the  directory when we are done */








    robust_close(pFile, pFile->dirfd, __LINE__);
    pFile->dirfd = -1;

  }
  return rc;
}

/*
** Truncate an open file to a specified size
*/
................................................................................
}

#if (SQLITE_ENABLE_APPLE_SPI>0) && defined(__APPLE__)
#include "sqlite3_private.h"
#include <copyfile.h>
static int getDbPathForUnixFile(unixFile *pFile, char *dbPath);
#endif


/*
** Information and control of an open file handle.
*/
static int unixFileControl(sqlite3_file *id, int op, void *pArg){
  switch( op ){
    case SQLITE_FCNTL_LOCKSTATE: {
................................................................................
    case SQLITE_GET_LOCKPROXYFILE: {
      return proxyFileControl(id,op,pArg);
    }
#endif /* SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__) */
#if (SQLITE_ENABLE_APPLE_SPI>0) && defined(__APPLE__)
    case SQLITE_TRUNCATE_DATABASE: {
      unixFile *pFile = (unixFile*)id;
      int trc = SQLITE_OK;
      int eFileLock = pFile->eFileLock;
      int rc = SQLITE_OK;
      char jPath[MAXPATHLEN+9];
      size_t jLen;
      
      if( eFileLock<SQLITE_LOCK_SHARED ){
        rc = pFile->pMethod->xLock(id, SQLITE_LOCK_SHARED);




      }
      if( !rc && eFileLock<SQLITE_LOCK_EXCLUSIVE ){
        rc = pFile->pMethod->xLock(id, SQLITE_LOCK_EXCLUSIVE);

      }

      if( rc ){
        if( pFile->eFileLock > eFileLock ){
          pFile->pMethod->xUnlock(id, eFileLock);



        }

        return rc;
      }

      rc = pFile->pMethod->xTruncate(id, ((pFile->fsFlags & SQLITE_FSFLAGS_IS_MSDOS) != 0) ? 1L : 0L);
      if( !rc && (SQLITE_OK==getDbPathForUnixFile(pFile, jPath)) ){
        jLen = strlcat(jPath, "-journal", MAXPATHLEN+9);










        if( jLen < MAXPATHLEN+9 ){
          int jfd = open(jPath, O_TRUNC);
          if( (jfd == -1) ){

            if ( errno!=ENOENT ){
              perror(jPath);
            }
          } else {
            fsync(jfd);
            close(jfd);
          }
        }
      }else{
        trc=rc;
      }
      if( !trc ){
        trc = pFile->pMethod->xSync(id, SQLITE_SYNC_FULL);
      }
      if( pFile->eFileLock > eFileLock ){
        int unlockRC = pFile->pMethod->xUnlock(id, SQLITE_LOCK_SHARED);
        if (!rc) rc = unlockRC;

      }
      if( pFile->eFileLock > eFileLock ){
        int unlockRC = pFile->pMethod->xUnlock(id, SQLITE_LOCK_NONE);
        if (!rc) rc = unlockRC;
      }
      if( trc ){
        return trc;




      }
      return rc;
    }
      
    case SQLITE_REPLACE_DATABASE: {
      unixFile *pFile = (unixFile*)id;
      int trc = SQLITE_OK;
      int eFileLock = pFile->eFileLock;
      int rc = SQLITE_OK;
      char jPath[MAXPATHLEN+9];
      size_t jLen;
      sqlite3 *srcdb = (sqlite3 *)pArg;
      Btree *pSrcBtree = NULL;
      int eSrcFileLock = SQLITE_LOCK_NONE;
      int srcLockRC = -1;
      sqlite3_file *src_file = NULL;
      unixFile *pSrcFile = NULL;











      
      if( !sqlite3SafetyCheckOk(srcdb) ){
        return SQLITE_MISUSE;
      }
      if( eFileLock<SQLITE_LOCK_SHARED ){
        rc = pFile->pMethod->xLock(id, SQLITE_LOCK_SHARED);
      }
      if( !rc && eFileLock<SQLITE_LOCK_EXCLUSIVE ){













        rc = pFile->pMethod->xLock(id, SQLITE_LOCK_EXCLUSIVE);
      }
      if( !rc ){



        /* get the src file descriptor adhering to the db struct access rules 
         ** this code is modeled after sqlite3_file_control() in main.c
         */ 
        sqlite3_mutex_enter(srcdb->mutex);
        if( srcdb->nDb>0 ){
          pSrcBtree = srcdb->aDb[0].pBt;
        }
        if( pSrcBtree ){
          Pager *pSrcPager;
          sqlite3BtreeEnter(pSrcBtree);
          pSrcPager = sqlite3BtreePager(pSrcBtree);
          assert( pSrcPager!=0 );
          src_file = sqlite3PagerFile(pSrcPager);
          assert( src_file!=0 );
          if( src_file->pMethods ){

            pSrcFile = (unixFile *)src_file;
            eSrcFileLock = pSrcFile->eFileLock;
            if( eSrcFileLock<SQLITE_LOCK_SHARED ){
              rc = pSrcFile->pMethod->xLock(src_file, SQLITE_LOCK_SHARED);
              srcLockRC = rc; /* SQLITE_OK means we need to unlock later */
            } else if( eSrcFileLock==SQLITE_LOCK_EXCLUSIVE ){
              /* if the src database has an exclusive lock, verify that the
               ** it doesn't have a journal file with open transactions 
               */
              if( getDbPathForUnixFile(pSrcFile, jPath) ){


                rc = SQLITE_INTERNAL;
              }else{
                jLen = strlcat(jPath, "-journal", MAXPATHLEN+9);
                if( jLen < MAXPATHLEN+9 ){
                  int jfd = open(jPath, O_RDONLY);
                  if( jfd==-1 ){
                    if( errno!=ENOENT ){
                      pFile->lastErrno = errno;
                      rc = SQLITE_IOERR;
                    }
                  }else{
                    /* if the journal exists ensure there's no pending 
                     ** transaction by checking the journal header */
                    char magic[8];
                    ssize_t rlen = pread(jfd, magic, 8, 0);
                    if( rlen<0 ){
                      pFile->lastErrno = errno;
                      rc = SQLITE_IOERR;

                    }else if( rlen==8 ){
                      char test[8] = {'\0','\0','\0','\0','\0','\0','\0','\0'};
                      if( memcmp(magic,test,8) ){
                        rc = SQLITE_LOCKED;
                      }

                    }else if( rlen!=0 ){
                      rc = SQLITE_INTERNAL;
                    }

                    close(jfd);



                  }
                }
              }
            }
          }else{

            rc = SQLITE_MISUSE;
          }
          if( rc ){
            if( srcLockRC==SQLITE_OK ){
              pSrcFile->pMethod->xUnlock(src_file, eSrcFileLock);

            }
            sqlite3BtreeLeave(pSrcBtree);

























          }
        }
        if( pSrcFile==NULL || (pSrcFile->h<0) ){
          rc = SQLITE_INTERNAL;
          sqlite3_mutex_leave(srcdb->mutex);


        }

      }
      if( rc ){
        /* unroll state changes and return error code */
        if( pFile->eFileLock > eFileLock ){
          pFile->pMethod->xUnlock(id, eFileLock);





        }
        return rc;
      }else{
        /* both databases are locked appropriately, copy file data
         ** and then unroll the locks we added. 
         */
        copyfile_state_t s;
        

        s = copyfile_state_alloc();


        if( fcopyfile(pSrcFile->h, pFile->h, s, COPYFILE_ALL) ){

          switch(errno) {
            case ENOMEM:
              rc = SQLITE_NOMEM;
              break;
            default:

              rc = SQLITE_INTERNAL;
          }
        }
        copyfile_state_free(s);
        if( srcLockRC==SQLITE_OK ){
          pSrcFile->pMethod->xUnlock(src_file, eSrcFileLock);
        }

        sqlite3BtreeLeave(pSrcBtree);
        sqlite3_mutex_leave(srcdb->mutex);

      }
      
      if( !rc && (SQLITE_OK==getDbPathForUnixFile(pFile, jPath)) ){
        jLen = strlcat(jPath, "-journal", MAXPATHLEN+9);















        if( jLen < MAXPATHLEN+9 ){
          int jfd = open(jPath, O_TRUNC);
          if( (jfd == -1) ){

            if ( errno!=ENOENT ){
              perror(jPath);
            }
          } else {
            fsync(jfd);
            close(jfd);
          }
        }
      }else{
        trc=rc;
      }
      if( !trc ){

        trc = pFile->pMethod->xSync(id, SQLITE_SYNC_FULL);
      }
      if( pFile->eFileLock > eFileLock ){
        int unlockRC = pFile->pMethod->xUnlock(id, SQLITE_LOCK_SHARED);
        if (!rc) rc = unlockRC;
      }
      if( pFile->eFileLock > eFileLock ){
        int unlockRC = pFile->pMethod->xUnlock(id, SQLITE_LOCK_NONE);
        if (!rc) rc = unlockRC;




      }
      if( trc ){
        return trc;





      }
      return rc;
    }
#endif /* (SQLITE_ENABLE_APPLE_SPI>0) && defined(__APPLE__) */
    case SQLITE_FCNTL_SYNC_OMITTED: {
      return SQLITE_OK;  /* A no-op */
    }
................................................................................
      p->h = -1;
    }
    p->pInode->pShmNode = 0;
    sqlite3_free(p);
  }
}

static int isProxyLockingMode(unixFile *);
static const char *proxySharedMemoryBasePath(unixFile *);

/*
** Open a shared-memory area associated with open database file pDbFd.  
** This particular implementation uses mmapped files.
**
** The file used to implement shared-memory is in the same directory
................................................................................
      /* Check to see if another process is holding the dead-man switch.
      ** If not, truncate the file to zero length. 
      */
      rc = SQLITE_OK;
      if( unixShmSystemLock(pShmNode, F_WRLCK, UNIX_SHM_DMS, 1)==SQLITE_OK ){
        if( robust_ftruncate(pShmNode->h, 0) ){
          rc = unixLogError(SQLITE_IOERR_SHMOPEN, "ftruncate", zShmFilename);








        }
      }
      if( rc==SQLITE_OK ){
        rc = unixShmSystemLock(pShmNode, F_RDLCK, UNIX_SHM_DMS, 1);
      }
      if( rc ) goto shm_open_err;
    }
................................................................................
** original filename is unavailable.  But 8_3_NAMES is only used for
** FAT filesystems and permissions do not matter there, so just use
** the default permissions.
*/
static int findCreateFileMode(
  const char *zPath,              /* Path of file (possibly) being created */
  int flags,                      /* Flags passed as 4th argument to xOpen() */
  mode_t *pMode                   /* OUT: Permissions to open file with */


){
  int rc = SQLITE_OK;             /* Return Code */
  *pMode = SQLITE_DEFAULT_FILE_PERMISSIONS;
  if( flags & (SQLITE_OPEN_WAL|SQLITE_OPEN_MAIN_JOURNAL) ){
    char zDb[MAX_PATHNAME+1];     /* Database file path */
    int nDb;                      /* Number of valid bytes in zDb */
    struct stat sStat;            /* Output of stat() on database file */
................................................................................
    while( nDb>0 && zPath[nDb]!='-' ) nDb--;
    if( nDb==0 ) return SQLITE_OK;
    memcpy(zDb, zPath, nDb);
    zDb[nDb] = '\0';

    if( 0==stat(zDb, &sStat) ){
      *pMode = sStat.st_mode & 0777;


    }else{
      rc = SQLITE_IOERR_FSTAT;
    }
  }else if( flags & SQLITE_OPEN_DELETEONCLOSE ){
    *pMode = 0600;
  }
  return rc;
................................................................................
  int flags,                   /* Input flags to control the opening */
  int *pOutFlags               /* Output flags returned to SQLite core */
){
  unixFile *p = (unixFile *)pFile;
  int fd = -1;                   /* File descriptor returned by open() */
  int dirfd = -1;                /* Directory file descriptor */
  int openFlags = 0;             /* Flags to pass to open() */



  int eType = flags&0xFFFFFF00;  /* Type of file to open */

  int noLock;                    /* True to omit locking primitives */
  int rc = SQLITE_OK;            /* Function Return Code */

  int isExclusive  = (flags & SQLITE_OPEN_EXCLUSIVE);
  int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);
  int isCreate     = (flags & SQLITE_OPEN_CREATE);
  int isReadonly   = (flags & SQLITE_OPEN_READONLY);
................................................................................
  ** 'conch file' locking functions later on.  */
  if( isReadonly )  openFlags |= O_RDONLY;
  if( isReadWrite ) openFlags |= O_RDWR;
  if( isCreate )    openFlags |= O_CREAT;
  if( isExclusive ) openFlags |= (O_EXCL|O_NOFOLLOW);
  openFlags |= (O_LARGEFILE|O_BINARY);





  if( fd<0 ){
    mode_t openMode;              /* Permissions to create file with */


    rc = findCreateFileMode(zName, flags, &openMode);
    if( rc!=SQLITE_OK ){
      assert( !p->pUnused );
      assert( eType==SQLITE_OPEN_WAL || eType==SQLITE_OPEN_MAIN_JOURNAL );
      return rc;
    }
    fd = robust_open(zName, openFlags, openMode);
    OSTRACE(("OPENX   %-3d %s 0%o\n", fd, zName, openFlags));
................................................................................
      openFlags |= O_RDONLY;
      isReadonly = 1;
      fd = robust_open(zName, openFlags, openMode);
    }
    if( fd<0 ){
      rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zName);
      goto open_finished;










    }
  }
  assert( fd>=0 );
  if( pOutFlags ){
    *pOutFlags = flags;
  }

................................................................................
    int useProxy = 0;

    /* SQLITE_FORCE_PROXY_LOCKING==1 means force always use proxy, 0 means 
    ** never use proxy, NULL means use proxy for non-local files only.  */
    if( envforce!=NULL ){
      useProxy = atoi(envforce)>0;
    }else{
      struct statfs fsInfo;
      if( statfs(zPath, &fsInfo) == -1 ){
        /* In theory, the close(fd) call is sub-optimal. If the file opened
        ** with fd is a database file, and there are other connections open
        ** on that file that are currently holding advisory locks on it,
        ** then the call to close() will cancel those locks. In practice,
        ** we're assuming that statfs() doesn't fail very often. At least
        ** not while other file descriptors opened by the same process on
        ** the same file are working.  */
        p->lastErrno = errno;
        if( dirfd>=0 ){
          robust_close(p, dirfd, __LINE__);
        }
        robust_close(p, fd, __LINE__);
        rc = SQLITE_IOERR_ACCESS;
        goto open_finished;
      }
      useProxy = !(fsInfo.f_flags&MNT_LOCAL);
    }
    if( useProxy ){
      rc = fillInUnixFile(pVfs, fd, dirfd, pFile, zPath, noLock,
                          isDelete, isReadonly);
      if( rc==SQLITE_OK ){
        /* cache the pMethod in case the transform fails */
................................................................................
      if( fsync(fd)==-1 )
#else
      if( fsync(fd) )
#endif
      {
        rc = unixLogError(SQLITE_IOERR_DIR_FSYNC, "fsync", zPath);
      }





      robust_close(0, fd, __LINE__);

    }
  }
#endif
  return rc;
}

/*
................................................................................
struct proxyLockingContext {
  unixFile *conchFile;         /* Open conch file */
  char *conchFilePath;         /* Name of the conch file */
  unixFile *lockProxy;         /* Open proxy lock file */
  char *lockProxyPath;         /* Name of the proxy lock file */
  char *dbPath;                /* Name of the open file */
  int conchHeld;               /* 1 if the conch is held, -1 if lockless */

  void *oldLockingContext;     /* Original lockingcontext to restore on close */
  sqlite3_io_methods const *pOldMethod;     /* Original I/O methods for close */
};

/* 
** The proxy lock file path for the database at dbPath is written into lPath, 
** which must point to valid, writable memory large enough for a maxLen length
................................................................................

/* get the host ID via gethostuuid(), pHostID must point to PROXY_HOSTIDLEN 
** bytes of writable memory.
*/
static int proxyGetHostID(unsigned char *pHostID, int *pError){
  assert(PROXY_HOSTIDLEN == sizeof(uuid_t));
  memset(pHostID, 0, PROXY_HOSTIDLEN);
#if defined(__MAX_OS_X_VERSION_MIN_REQUIRED)\
               && __MAC_OS_X_VERSION_MIN_REQUIRED<1050
  {
    static const struct timespec timeout = {1, 0}; /* 1 sec timeout */

    if( gethostuuid(pHostID, &timeout) ){
      int err = errno;
      if( pError ){
        *pError = err;
      }
      return SQLITE_IOERR;
    }
................................................................................
/* Take the requested lock on the conch file and break a stale lock if the 
** host id matches.
*/
static int proxyConchLock(unixFile *pFile, uuid_t myHostID, int lockType){
  proxyLockingContext *pCtx = (proxyLockingContext *)pFile->lockingContext; 
  unixFile *conchFile = pCtx->conchFile;
  int rc = SQLITE_OK;
  int nTries = 0;
  struct timespec conchModTime;
  
  do {
    rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, lockType);
    nTries ++;
    if( rc==SQLITE_BUSY ){

      /* If the lock failed (busy):
       * 1st try: get the mod time of the conch, wait 0.5s and try again. 
       * 2nd try: fail if the mod time changed or host id is different, wait 
       *           10 sec and try again
       * 3rd try: break the lock unless the mod time has changed.
       */
      struct stat buf;
      if( osFstat(conchFile->h, &buf) ){
        pFile->lastErrno = errno;
        return SQLITE_IOERR_LOCK;
      }
      
      if( nTries==1 ){
        conchModTime = buf.st_mtimespec;
        usleep(500000); /* wait 0.5 sec and try the lock again*/
        continue;  
      }

      assert( nTries>1 );
      if( conchModTime.tv_sec != buf.st_mtimespec.tv_sec || 
         conchModTime.tv_nsec != buf.st_mtimespec.tv_nsec ){
        return SQLITE_BUSY;
      }
      
      if( nTries==2 ){  
        char tBuf[PROXY_MAXCONCHLEN];
        int len = osPread(conchFile->h, tBuf, PROXY_MAXCONCHLEN, 0);
        if( len<0 ){
          pFile->lastErrno = errno;
          return SQLITE_IOERR_LOCK;
        }
        if( len>PROXY_PATHINDEX && tBuf[0]==(char)PROXY_CONCHVERSION){
          /* don't break the lock if the host id doesn't match */



          if( 0!=memcmp(&tBuf[PROXY_HEADERLEN], myHostID, PROXY_HOSTIDLEN) ){












            return SQLITE_BUSY;
          }
        }else{
          /* don't break the lock on short read or a version mismatch */
          return SQLITE_BUSY;
        }
        usleep(10000000); /* wait 10 sec and try the lock again */
        continue; 
      }
      
      assert( nTries==3 );
      if( 0==proxyBreakConchLock(pFile, myHostID) ){
        rc = SQLITE_OK;
        if( lockType==EXCLUSIVE_LOCK ){
          rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, SHARED_LOCK);          
        }
        if( !rc ){
          rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, lockType);
        }
      }
    }
  } while( rc==SQLITE_BUSY && nTries<3 );
  
  return rc;
}

/* Takes the conch by taking a shared lock and read the contents conch, if 
** lockPath is non-NULL, the host ID and lock file path must match.  A NULL 
** lockPath means that the lockPath in the conch file will be used if the 
................................................................................
          /* We are trying for an exclusive lock but another thread in this
           ** same process is still holding a shared lock. */
          rc = SQLITE_BUSY;
        } else {          
          rc = proxyConchLock(pFile, myHostID, EXCLUSIVE_LOCK);
        }
      }else{
        rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, EXCLUSIVE_LOCK);
      }
      if( rc==SQLITE_OK ){
        char writeBuffer[PROXY_MAXCONCHLEN];
        int writeSize = 0;
        
        writeBuffer[0] = (char)PROXY_CONCHVERSION;
        memcpy(&writeBuffer[PROXY_HEADERLEN], myHostID, PROXY_HOSTIDLEN);
................................................................................
      }
      conchFile->pMethod->xUnlock((sqlite3_file*)conchFile, SHARED_LOCK);
      
    end_takeconch:
      OSTRACE(("TRANSPROXY: CLOSE  %d\n", pFile->h));
      if( rc==SQLITE_OK && pFile->openFlags ){
        if( pFile->h>=0 ){






          robust_close(pFile, pFile->h, __LINE__);

        }
        pFile->h = -1;
        int fd = robust_open(pCtx->dbPath, pFile->openFlags,
                      SQLITE_DEFAULT_FILE_PERMISSIONS);
        OSTRACE(("TRANSPROXY: OPEN  %d\n", fd));
        if( fd>=0 ){
          pFile->h = fd;

#include <errno.h>
#ifndef SQLITE_OMIT_WAL
#include <sys/mman.h>
#endif

#if SQLITE_ENABLE_LOCKING_STYLE
# include <sys/ioctl.h>
# include <uuid/uuid.h>
# if defined(__APPLE__) && ((__MAC_OS_X_VERSION_MIN_REQUIRED > 1050) || \
                            (__IPHONE_OS_VERSION_MIN_REQUIRED > 2000))
#  define HAVE_GETHOSTUUID 1
# endif
# if OS_VXWORKS
#  include <semaphore.h>
#  include <limits.h>
# else
#  include <sys/file.h>
#  include <sys/param.h>
# endif
................................................................................
  UnixUnusedFd *pUnused;              /* Pre-allocated UnixUnusedFd */
  const char *zPath;                  /* Name of the file */
  unixShm *pShm;                      /* Shared memory segment information */
  int szChunk;                        /* Configured by FCNTL_CHUNK_SIZE */
#if SQLITE_ENABLE_LOCKING_STYLE
  int openFlags;                      /* The flags specified at open() */
#endif
#if SQLITE_ENABLE_DATA_PROTECTION
  int protFlags;                      /* Data protection flags from unixOpen */
#endif
#if SQLITE_ENABLE_LOCKING_STYLE || defined(__APPLE__)
  unsigned fsFlags;                   /* cached details from statfs() */
#endif
#if OS_VXWORKS
  int isDelete;                       /* Delete on close if true */
  struct vxworksFileId *pId;          /* Unique file ID */
#endif
................................................................................
** testing and debugging only.
*/
#if SQLITE_THREADSAFE
#define threadid pthread_self()
#else
#define threadid 0
#endif

#ifdef __APPLE__
#define SQLITE_ENABLE_SUPERLOCK 1
#endif

#if SQLITE_ENABLE_SUPERLOCK
#include "sqlite3.h"
#include <string.h>               /* memset(), strlen() */
#include <assert.h>               /* assert() */

/*
** A structure to collect a busy-handler callback and argument and a count
** of the number of times it has been invoked.
*/
struct SuperlockBusy {
  int (*xBusy)(void*,int);        /* Pointer to busy-handler function */
  void *pBusyArg;                 /* First arg to pass to xBusy */
  int nBusy;                      /* Number of times xBusy has been invoked */
};
typedef struct SuperlockBusy SuperlockBusy;

/*
** An instance of the following structure is allocated for each active
** superlock. The opaque handle returned by sqlite3demo_superlock() is
** actually a pointer to an instance of this structure.
*/
struct Superlock {
  sqlite3 *db;                    /* Database handle used to lock db */
  int bWal;                       /* True if db is a WAL database */
};
typedef struct Superlock Superlock;

/*
** The pCtx pointer passed to this function is actually a pointer to a
** SuperlockBusy structure. Invoke the busy-handler function encapsulated
** by the structure and return the result.
*/
static int superlockBusyHandler(void *pCtx, int UNUSED){
  SuperlockBusy *pBusy = (SuperlockBusy *)pCtx;
  if( pBusy->xBusy==0 ) return 0;
  return pBusy->xBusy(pBusy->pBusyArg, pBusy->nBusy++);
}

/*
** This function is used to determine if the main database file for 
** connection db is open in WAL mode or not. If no error occurs and the
** database file is in WAL mode, set *pbWal to true and return SQLITE_OK.
** If it is not in WAL mode, set *pbWal to false.
**
** If an error occurs, return an SQLite error code. The value of *pbWal
** is undefined in this case.
*/
static int superlockIsWal(Superlock *pLock){
  int rc;                         /* Return Code */
  sqlite3_stmt *pStmt;            /* Compiled PRAGMA journal_mode statement */

  rc = sqlite3_prepare(pLock->db, "PRAGMA main.journal_mode", -1, &pStmt, 0);
  if( rc!=SQLITE_OK ) return rc;

  pLock->bWal = 0;
  if( SQLITE_ROW==sqlite3_step(pStmt) ){
    const char *zMode = (const char *)sqlite3_column_text(pStmt, 0);
    if( zMode && strlen(zMode)==3 && sqlite3_strnicmp("wal", zMode, 3)==0 ){
      pLock->bWal = 1;
    }
  }

  return sqlite3_finalize(pStmt);
}

/*
** Obtain an exclusive shm-lock on nByte bytes starting at offset idx
** of the file fd. If the lock cannot be obtained immediately, invoke
** the busy-handler until either it is obtained or the busy-handler
** callback returns 0.
*/
static int superlockShmLock(
  sqlite3_file *fd,               /* Database file handle */
  int idx,                        /* Offset of shm-lock to obtain */
  int nByte,                      /* Number of consective bytes to lock */
  SuperlockBusy *pBusy            /* Busy-handler wrapper object */
){
  int rc;
  int (*xShmLock)(sqlite3_file*, int, int, int) = fd->pMethods->xShmLock;
  do {
    rc = xShmLock(fd, idx, nByte, SQLITE_SHM_LOCK|SQLITE_SHM_EXCLUSIVE);
  }while( rc==SQLITE_BUSY && superlockBusyHandler((void *)pBusy, 0) );
  return rc;
}

/*
** Obtain the extra locks on the database file required for WAL databases.
** Invoke the supplied busy-handler as required.
*/
static int superlockWalLock(
  sqlite3 *db,                    /* Database handle open on WAL database */
  SuperlockBusy *pBusy            /* Busy handler wrapper object */
){
  int rc;                         /* Return code */
  sqlite3_file *fd = 0;           /* Main database file handle */
  void volatile *p = 0;           /* Pointer to first page of shared memory */

  /* Obtain a pointer to the sqlite3_file object open on the main db file. */
  rc = sqlite3_file_control(db, "main", SQLITE_FCNTL_FILE_POINTER, (void *)&fd);
  if( rc!=SQLITE_OK ) return rc;

  /* Obtain the "recovery" lock. Normally, this lock is only obtained by
  ** clients running database recovery.  
  */
  rc = superlockShmLock(fd, 2, 1, pBusy);
  if( rc!=SQLITE_OK ) return rc;

  /* Zero the start of the first shared-memory page. This means that any
  ** clients that open read or write transactions from this point on will
  ** have to run recovery before proceeding. Since they need the "recovery"
  ** lock that this process is holding to do that, no new read or write
  ** transactions may now be opened. Nor can a checkpoint be run, for the
  ** same reason.
  */
  rc = fd->pMethods->xShmMap(fd, 0, 32*1024, 1, &p);
  if( rc!=SQLITE_OK ) return rc;
  memset((void *)p, 0, 32);

  /* Obtain exclusive locks on all the "read-lock" slots. Once these locks
  ** are held, it is guaranteed that there are no active reader, writer or 
  ** checkpointer clients.
  */
  rc = superlockShmLock(fd, 3, SQLITE_SHM_NLOCK-3, pBusy);
  return rc;
}

/*
** Release a superlock held on a database file. The argument passed to 
** this function must have been obtained from a successful call to
** sqlite3demo_superlock().
*/
static void sqlite3demo_superunlock(void *pLock){
  Superlock *p = (Superlock *)pLock;
  if( p->bWal ){
    int rc;                         /* Return code */
    int flags = SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE;
    sqlite3_file *fd = 0;
    rc = sqlite3_file_control(p->db, "main", SQLITE_FCNTL_FILE_POINTER, (void *)&fd);
    if( rc==SQLITE_OK ){
      fd->pMethods->xShmLock(fd, 2, 1, flags);
      fd->pMethods->xShmLock(fd, 3, SQLITE_SHM_NLOCK-3, flags);
    }
  }
  sqlite3_close(p->db);
  sqlite3_free(p);
}

/*
** Obtain a superlock on the database file identified by zPath, using the
** locking primitives provided by VFS zVfs. If successful, SQLITE_OK is
** returned and output variable *ppLock is populated with an opaque handle
** that may be used with sqlite3demo_superunlock() to release the lock.
**
** If an error occurs, *ppLock is set to 0 and an SQLite error code 
** (e.g. SQLITE_BUSY) is returned.
**
** If a required lock cannot be obtained immediately and the xBusy parameter
** to this function is not NULL, then xBusy is invoked in the same way
** as a busy-handler registered with SQLite (using sqlite3_busy_handler())
** until either the lock can be obtained or the busy-handler function returns
** 0 (indicating "give up").
*/
static int sqlite3demo_superlock(
  const char *zPath,              /* Path to database file to lock */
  const char *zVfs,               /* VFS to use to access database file */
  int flags,                      /* Additional flags to pass to sqlite3_open_v2 */
  int (*xBusy)(void*,int),        /* Busy handler callback */
  void *pBusyArg,                 /* Context arg for busy handler */
  void **ppLock                   /* OUT: Context to pass to superunlock() */
){
  SuperlockBusy busy = {0, 0, 0}; /* Busy handler wrapper object */
  int rc;                         /* Return code */
  Superlock *pLock;

  pLock = sqlite3_malloc(sizeof(Superlock));
  if( !pLock ) return SQLITE_NOMEM;
  memset(pLock, 0, sizeof(Superlock));

  /* Open a database handle on the file to superlock. */
  rc = sqlite3_open_v2(
      zPath, &pLock->db, SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|flags, zVfs
  );

  /* Install a busy-handler and execute a BEGIN EXCLUSIVE. If this is not
  ** a WAL database, this is all we need to do.  
  **
  ** A wrapper function is used to invoke the busy-handler instead of
  ** registering the busy-handler function supplied by the user directly
  ** with SQLite. This is because the same busy-handler function may be
  ** invoked directly later on when attempting to obtain the extra locks
  ** required in WAL mode. By using the wrapper, we are able to guarantee
  ** that the "nBusy" integer parameter passed to the users busy-handler
  ** represents the total number of busy-handler invocations made within
  ** this call to sqlite3demo_superlock(), including any made during the
  ** "BEGIN EXCLUSIVE".
  */
  if( rc==SQLITE_OK ){
    busy.xBusy = xBusy;
    busy.pBusyArg = pBusyArg;
    sqlite3_busy_handler(pLock->db, superlockBusyHandler, (void *)&busy);
    rc = sqlite3_exec(pLock->db, "BEGIN EXCLUSIVE", 0, 0, 0);
  }

  /* If the BEGIN EXCLUSIVE was executed successfully and this is a WAL
  ** database, call superlockWalLock() to obtain the extra locks required
  ** to prevent readers, writers and/or checkpointers from accessing the
  ** db while this process is holding the superlock.
  **
  ** Before attempting any WAL locks, commit the transaction started above
  ** to drop the WAL read and write locks currently held. Otherwise, the
  ** new WAL locks may conflict with the old.
  */
  if( rc==SQLITE_OK ){
    if( SQLITE_OK==(rc = superlockIsWal(pLock)) && pLock->bWal ){
      rc = sqlite3_exec(pLock->db, "COMMIT", 0, 0, 0);
      if( rc==SQLITE_OK ){
        rc = superlockWalLock(pLock->db, &busy);
      }
    }
  }

  if( rc!=SQLITE_OK ){
    sqlite3demo_superunlock(pLock);
    *ppLock = 0;
  }else{
    *ppLock = pLock;
  }

  return rc;
}

/* A corrupt DB won't work with the sql-based locking attempt, grab an 
** exclusive lock and return SQLITE_OK or SQLITE_BUSY if the lock fails 
** returns the current lock level held on sqlite3_file
*/
static int sqlite3demo_superlock_corrupt(sqlite3_file *id, int eTargetFileLock, int *pFileLock) {
  unixFile *pFile = (unixFile*)id;
  int eFileLock = pFile->eFileLock;
  int rc = SQLITE_OK;
  
  if( eFileLock<eTargetFileLock ){
    rc = pFile->pMethod->xLock(id, SQLITE_LOCK_SHARED);
  }
  if( !rc && eFileLock<eTargetFileLock ){
    rc = pFile->pMethod->xLock(id, SQLITE_LOCK_EXCLUSIVE);
  }
  if( rc ){
    if( pFile->eFileLock > eFileLock ){
      pFile->pMethod->xUnlock(id, eFileLock);
    }
    return rc;
  }
  if (pFileLock) {
    *pFileLock = eFileLock;
  }
  return SQLITE_OK;
}

static int sqlite3demo_superunlock_corrupt(sqlite3_file *id, int eFileLock) {
  unixFile *pFile = (unixFile*)id;
  int rc = SQLITE_OK;
  
  if( pFile->eFileLock > eFileLock ){
    rc = pFile->pMethod->xUnlock(id, SQLITE_LOCK_SHARED);
  }
  if( pFile->eFileLock > eFileLock ){
    int unlockRC = pFile->pMethod->xUnlock(id, SQLITE_LOCK_NONE);
    if (!rc) rc = unlockRC;
  }
  return rc;
}

#endif /* SQLITE_ENABLE_SUPERLOCK */


/*
** Different Unix systems declare open() in different ways.  Same use
** open(const char*,int,mode_t).  Others use open(const char*,int,...).
** The difference is important when using a pointer to the function.
**
** The safest way to deal with the problem is to always use this wrapper
................................................................................
*/ 
static void closePendingFds(unixFile *pFile){
  unixInodeInfo *pInode = pFile->pInode;
  UnixUnusedFd *p;
  UnixUnusedFd *pNext;
  for(p=pInode->pUnused; p; p=pNext){
    pNext = p->pNext;
#if OSCLOSE_CHECK_CLOSE_IOERR
    if( close(p->fd) ){
      pFile->lastErrno = errno;
      rc = SQLITE_IOERR_CLOSE;
      p->pNext = pError;
      pError = p;
    }else{
      sqlite3_free(p);
    }
#else
    robust_close(pFile, p->fd, __LINE__);
    sqlite3_free(p);
#endif
  }
  pInode->pUnused = 0;
}

/*
** Release a unixInodeInfo structure previously allocated by findInodeInfo().
**
................................................................................
  if( !reserved && !pFile->pInode->bProcessLock ){
    struct flock lock;
    lock.l_whence = SEEK_SET;
    lock.l_start = RESERVED_BYTE;
    lock.l_len = 1;
    lock.l_type = F_WRLCK;
    if( osFcntl(pFile->h, F_GETLK, &lock) ){
#if OSLOCKING_CHECK_BUSY_IOERR
      int tErrno = errno;
      rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_CHECKRESERVEDLOCK);
      pFile->lastErrno = tErrno;
#else
      rc = SQLITE_IOERR_CHECKRESERVEDLOCK;
      pFile->lastErrno = errno;
#endif
    } else if( lock.l_type!=F_UNLCK ){
      reserved = 1;
    }
  }
#endif
  
  unixLeaveMutex();
................................................................................
      || (eFileLock==EXCLUSIVE_LOCK && pFile->eFileLock<PENDING_LOCK)
  ){
    lock.l_type = (eFileLock==SHARED_LOCK?F_RDLCK:F_WRLCK);
    lock.l_start = PENDING_BYTE;
    if( unixFileLock(pFile, &lock) ){
      tErrno = errno;
      rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
      if( IS_LOCK_ERROR(rc) ){
        pFile->lastErrno = tErrno;
      }
      goto end_lock;
    }
  }


................................................................................
    /* Drop the temporary PENDING lock */
    lock.l_start = PENDING_BYTE;
    lock.l_len = 1L;
    lock.l_type = F_UNLCK;
    if( unixFileLock(pFile, &lock) && rc==SQLITE_OK ){
      /* This could happen with a network mount */
      tErrno = errno;
#if OSLOCKING_CHECK_BUSY_IOERR
      rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_UNLOCK); 
#else
      rc = SQLITE_IOERR_UNLOCK; 
#endif
    }

    if( rc ){
      if( IS_LOCK_ERROR(rc) ){
        pFile->lastErrno = tErrno;
      }
      goto end_lock;
    }else{
      pFile->eFileLock = SHARED_LOCK;
      pInode->nLock++;
      pInode->nShared = 1;
................................................................................
        
        lock.l_type = F_UNLCK;
        lock.l_whence = SEEK_SET;
        lock.l_start = SHARED_FIRST;
        lock.l_len = divSize;
        if( unixFileLock(pFile, &lock)==(-1) ){
          tErrno = errno;
#if OSLOCKING_CHECK_BUSY_IOERR
          rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_UNLOCK);
#else
          rc = SQLITE_IOERR_UNLOCK;
#endif
          if( IS_LOCK_ERROR(rc) ){
            pFile->lastErrno = tErrno;
          }
          goto end_unlock;
        }
        lock.l_type = F_RDLCK;
        lock.l_whence = SEEK_SET;
................................................................................
        }
        lock.l_type = F_UNLCK;
        lock.l_whence = SEEK_SET;
        lock.l_start = SHARED_FIRST+divSize;
        lock.l_len = SHARED_SIZE-divSize;
        if( unixFileLock(pFile, &lock)==(-1) ){
          tErrno = errno;
#if OSLOCKING_CHECK_BUSY_IOERR
          rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_UNLOCK);
#else
          rc = SQLITE_IOERR_UNLOCK;
#endif
          if( IS_LOCK_ERROR(rc) ){
            pFile->lastErrno = tErrno;
          }
          goto end_unlock;
        }
      }else
#endif /* defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE */
      {
        lock.l_type = F_RDLCK;
        lock.l_whence = SEEK_SET;
        lock.l_start = SHARED_FIRST;
        lock.l_len = SHARED_SIZE;
        if( unixFileLock(pFile, &lock) ){
#if OSLOCKING_CHECK_BUSY_IOERR
          tErrno = errno;
          rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_RDLOCK);
          if( IS_LOCK_ERROR(rc) ){
            pFile->lastErrno = tErrno;
          }
#else
          /* In theory, the call to unixFileLock() cannot fail because another
          ** process is holding an incompatible lock. If it does, this 
          ** indicates that the other process is not following the locking
          ** protocol. If this happens, return SQLITE_IOERR_RDLOCK. Returning
          ** SQLITE_BUSY would confuse the upper layer (in practice it causes 
          ** an assert to fail). */ 
          rc = SQLITE_IOERR_RDLOCK;
          pFile->lastErrno = errno;
#endif
          goto end_unlock;
        }
      }
    }
    lock.l_type = F_UNLCK;
    lock.l_whence = SEEK_SET;
    lock.l_start = PENDING_BYTE;
    lock.l_len = 2L;  assert( PENDING_BYTE+1==RESERVED_BYTE );
    if( unixFileLock(pFile, &lock)==0 ){
      pInode->eFileLock = SHARED_LOCK;
    }else{
#if OSLOCKING_CHECK_BUSY_IOERR
      tErrno = errno;
      rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_UNLOCK);
      if( IS_LOCK_ERROR(rc) ){
        pFile->lastErrno = tErrno;
      }
#else
      rc = SQLITE_IOERR_UNLOCK;
      pFile->lastErrno = errno;
#endif
      goto end_unlock;
    }
  }
  if( eFileLock==NO_LOCK ){
    /* Decrement the shared lock counter.  Release the lock using an
    ** OS call only when all threads in this same process have released
    ** the lock.
................................................................................
      lock.l_start = lock.l_len = 0L;
      SimulateIOErrorBenign(1);
      SimulateIOError( h=(-1) )
      SimulateIOErrorBenign(0);
      if( unixFileLock(pFile, &lock)==0 ){
        pInode->eFileLock = NO_LOCK;
      }else{
#if OSLOCKING_CHECK_BUSY_IOERR
        tErrno = errno;
        rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_UNLOCK);
        if( IS_LOCK_ERROR(rc) ){
          pFile->lastErrno = tErrno;
        }
#else
        rc = SQLITE_IOERR_UNLOCK;
	    pFile->lastErrno = errno;
#endif
        pInode->eFileLock = NO_LOCK;
        pFile->eFileLock = NO_LOCK;
      }
    }

    /* Decrement the count of locks against this same file.  When the
    ** count reaches zero, close any other file descriptors whose close
................................................................................
**
** It is *not* necessary to hold the mutex when this routine is called,
** even on VxWorks.  A mutex will be acquired on VxWorks by the
** vxworksReleaseFileId() routine.
*/
static int closeUnixFile(sqlite3_file *id){
  unixFile *pFile = (unixFile*)id;
#if OSCLOSE_CHECK_CLOSE_IOERR
  if( pFile->dirfd>=0 ){
    int err = close(pFile->dirfd);
    if( err ){
      pFile->lastErrno = errno;
      return SQLITE_IOERR_DIR_CLOSE;
    }else{
      pFile->dirfd=-1;
    }
  }
  if( pFile->h>=0 ){
    int err = close(pFile->h);
    if( err ){
      pFile->lastErrno = errno;
      return SQLITE_IOERR_CLOSE;
    }else{
      pFile->h=-1;
    }
  }
#else
  if( pFile->dirfd>=0 ){
    robust_close(pFile, pFile->dirfd, __LINE__);
    pFile->dirfd=-1;
  }
  if( pFile->h>=0 ){
    robust_close(pFile, pFile->h, __LINE__);
    pFile->h = -1;
  }
#endif
#if OS_VXWORKS
  if( pFile->pId ){
    if( pFile->isDelete ){
      unlink(pFile->pId->zCanonicalName);
    }
    vxworksReleaseFileId(pFile->pId);
    pFile->pId = 0;
................................................................................
      rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
      if( IS_LOCK_ERROR(rc) ){
        pFile->lastErrno = tErrno;
      }
    }
    return rc;
  } 
#if OSCLOSE_CHECK_CLOSE_IOERR
  if( close(fd) ){
    pFile->lastErrno = errno;
    rc = SQLITE_IOERR_CLOSE;
  }
#else
  robust_close(pFile, fd, __LINE__);
#endif
  
  /* got it, set the type and return ok */
  pFile->eFileLock = eFileLock;
  return rc;
}

/*
................................................................................
  
  /* To fully unlock the database, delete the lock file */
  assert( eFileLock==NO_LOCK );
  if( unlink(zLockFile) ){
    int rc = 0;
    int tErrno = errno;
    if( ENOENT != tErrno ){
#if OSLOCKING_CHECK_BUSY_IOERR
      rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_UNLOCK);
#else
      rc = SQLITE_IOERR_UNLOCK;
#endif
    }
    if( IS_LOCK_ERROR(rc) ){
      pFile->lastErrno = tErrno;
    }
    return rc; 
  }
  pFile->eFileLock = NO_LOCK;
................................................................................
    int lrc = robust_flock(pFile->h, LOCK_EX | LOCK_NB);
    if( !lrc ){
      /* got the lock, unlock it */
      lrc = robust_flock(pFile->h, LOCK_UN);
      if ( lrc ) {
        int tErrno = errno;
        /* unlock failed with an error */
#if OSLOCKING_CHECK_BUSY_IOERR
        lrc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_UNLOCK);
#else 
        lrc = SQLITE_IOERR_UNLOCK; 
#endif
        if( IS_LOCK_ERROR(lrc) ){
          pFile->lastErrno = tErrno;
          rc = lrc;
        }
      }
    } else {
      int tErrno = errno;
................................................................................
       ** A failed directory sync is not a big deal.  So it seems
       ** better to ignore the error.  Ticket #1657
       */
       /* pFile->lastErrno = errno; */
       /* return SQLITE_IOERR; */
    }
#endif
  /* Only need to sync once, so close the  directory when we are done */
#if OSCLOSE_CHECK_CLOSE_IOERR
    if( close(pFile->dirfd)==0 ){
      pFile->dirfd = -1;
    }else{
      pFile->lastErrno = errno;
      rc = SQLITE_IOERR_DIR_CLOSE;
    }
#else
    robust_close(pFile, pFile->dirfd, __LINE__);
    pFile->dirfd = -1;
#endif
  }
  return rc;
}

/*
** Truncate an open file to a specified size
*/
................................................................................
}

#if (SQLITE_ENABLE_APPLE_SPI>0) && defined(__APPLE__)
#include "sqlite3_private.h"
#include <copyfile.h>
static int getDbPathForUnixFile(unixFile *pFile, char *dbPath);
#endif
static int isProxyLockingMode(unixFile *);

/*
** Information and control of an open file handle.
*/
static int unixFileControl(sqlite3_file *id, int op, void *pArg){
  switch( op ){
    case SQLITE_FCNTL_LOCKSTATE: {
................................................................................
    case SQLITE_GET_LOCKPROXYFILE: {
      return proxyFileControl(id,op,pArg);
    }
#endif /* SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__) */
#if (SQLITE_ENABLE_APPLE_SPI>0) && defined(__APPLE__)
    case SQLITE_TRUNCATE_DATABASE: {
      unixFile *pFile = (unixFile*)id;
      int rc = SQLITE_OK;
      void *pLock = NULL;
      int flags = 0;
      int corruptFileLock = 0;
      int isCorrupt = 0;

#if SQLITE_ENABLE_DATA_PROTECTION
      flags |= pFile->protFlags;
#endif
#if SQLITE_ENABLE_LOCKING_STYLE
      if( isProxyLockingMode(pFile) ){
        flags |= SQLITE_OPEN_AUTOPROXY;
      }


#endif
      
      rc = sqlite3demo_superlock(pFile->zPath, 0, flags, 0, 0, &pLock);
      if( rc ){


        if( rc==SQLITE_CORRUPT || rc==SQLITE_NOTADB ){
          isCorrupt = 1;
          rc = sqlite3demo_superlock_corrupt(id, SQLITE_LOCK_EXCLUSIVE, &corruptFileLock);
        }
        if( rc ){
          return rc;
        }
      }
      rc = pFile->pMethod->xTruncate(id, ((pFile->fsFlags & SQLITE_FSFLAGS_IS_MSDOS) != 0) ? 1L : 0L);



      if( rc==SQLITE_OK ){
        char jPath[MAXPATHLEN+9];
        int zLen = strlcpy(jPath, pFile->zPath, MAXPATHLEN+9);
        if( zLen<MAXPATHLEN ){
          size_t jLen;
          const char extensions[2][9] = { "-wal", "-journal" /*, "-shm" */ };
          int j = 0;
          for( j=0; j<2; j++ ){
            jLen = strlcpy(&jPath[zLen], extensions[j], 9);
            if( jLen < 9 ){
              int jfd = open(jPath, O_TRUNC);

              if( jfd==(-1) ){
                if ( errno!=ENOENT ){
                  perror(jPath);
                }
              } else {
                fsync(jfd);
                close(jfd);
              }
            }


          }


        }



        pFile->pMethod->xSync(id, SQLITE_SYNC_FULL);
      }






      if( isCorrupt ){
        sqlite3demo_superunlock_corrupt(id, corruptFileLock);
      }else{
        sqlite3demo_superunlock(pLock);
      }
      return rc;
    }
      
    case SQLITE_REPLACE_DATABASE: {
      unixFile *pFile = (unixFile*)id;





      sqlite3 *srcdb = (sqlite3 *)pArg;
      Btree *pSrcBtree = NULL;


      sqlite3_file *src_file = NULL;
      unixFile *pSrcFile = NULL;
      char srcWalPath[MAXPATHLEN+5];
      int srcWalFD = -1;
      int rc = SQLITE_OK;
      void *pLock = NULL;
      int flags = 0;
      sqlite3 *srcdb2 = NULL;
      copyfile_state_t s;
      int corruptSrcFileLock = 0;
      int corruptDstFileLock = 0;
      int isSrcCorrupt = 0;
      int isDstCorrupt = 0;

      if( !sqlite3SafetyCheckOk(srcdb) ){
        return SQLITE_MISUSE;
      }


      

#if SQLITE_ENABLE_DATA_PROTECTION
      flags |= pFile->protFlags;
#endif
#if SQLITE_ENABLE_LOCKING_STYLE
      if( isProxyLockingMode(pFile) ){
        flags |= SQLITE_OPEN_AUTOPROXY;
      }
#endif
      
      rc = sqlite3demo_superlock(pFile->zPath, 0, flags, 0, 0, &pLock);
      if( rc ){
        if( rc==SQLITE_CORRUPT || rc==SQLITE_NOTADB ){
          isDstCorrupt = 1;
          rc = sqlite3demo_superlock_corrupt(id, SQLITE_LOCK_EXCLUSIVE, &corruptDstFileLock);
        }
        if( rc ){
          return rc;
        }
      }
      /* get the src file descriptor adhering to the db struct access rules 
       ** this code is modeled after sqlite3_file_control() in main.c
       */ 
      sqlite3_mutex_enter(srcdb->mutex);
      if( srcdb->nDb>0 ){
        pSrcBtree = srcdb->aDb[0].pBt;
      }
      if( pSrcBtree ){
        Pager *pSrcPager;
        sqlite3BtreeEnter(pSrcBtree);
        pSrcPager = sqlite3BtreePager(pSrcBtree);
        assert( pSrcPager!=0 );
        src_file = sqlite3PagerFile(pSrcPager);
        assert( src_file!=0 );
        if( src_file->pMethods ){
          int srcFlags = 0;
          pSrcFile = (unixFile *)src_file;









          /* wal mode db cannot be opened readonly */
          if ((pSrcFile->openFlags & O_RDWR) == O_RDWR) {
            srcFlags = SQLITE_OPEN_READWRITE;
          } else {






            srcFlags = SQLITE_OPEN_READONLY;
          }





#if SQLITE_ENABLE_DATA_PROTECTION
          srcFlags |= pSrcFile->protFlags;

#endif
#if SQLITE_ENABLE_LOCKING_STYLE
          if( isProxyLockingMode(pSrcFile) ){
            srcFlags |= SQLITE_OPEN_AUTOPROXY;

          }
#endif
          rc = sqlite3_open_v2(pSrcFile->zPath, &srcdb2, srcFlags, 0);
          if( rc==SQLITE_OK ){

            /* start a deferred transaction and read to establish a read lock */
            rc = sqlite3_exec(srcdb2, "BEGIN DEFERRED; PRAGMA schema_version", 0, 0, 0);
            if( rc==SQLITE_CORRUPT || rc==SQLITE_NOTADB ){
              isSrcCorrupt = 1;
              rc = sqlite3demo_superlock_corrupt(src_file, SQLITE_LOCK_SHARED, &corruptSrcFileLock);
            }
          }
        }
      }

      if( !srcdb2 || pSrcFile==NULL || pSrcFile->h<0){
        rc = SQLITE_INTERNAL;
      }

      if( rc!=SQLITE_OK ){

        goto end_replace_database;
      }

      /* both databases are locked appropriately, copy the src wal journal if 
      ** one exists and then the actual database file
      */
      strlcpy(srcWalPath, pSrcFile->zPath, MAXPATHLEN+5);
      strlcat(srcWalPath, "-wal", MAXPATHLEN+5);
      srcWalFD = open(srcWalPath, O_RDONLY);
      if( !(srcWalFD<0) ){
        char dstWalPath[MAXPATHLEN+5];
        int dstWalFD = -1;
        strlcpy(dstWalPath, pFile->zPath, MAXPATHLEN+5);
        strlcat(dstWalPath, "-wal", MAXPATHLEN+5);
        dstWalFD = open(dstWalPath, O_RDWR|O_CREAT, SQLITE_DEFAULT_FILE_PERMISSIONS);
        if( !(dstWalFD<0) ){
          s = copyfile_state_alloc();
          lseek(srcWalFD, 0, SEEK_SET);
          lseek(dstWalFD, 0, SEEK_SET);
          if( fcopyfile(srcWalFD, dstWalFD, s, COPYFILE_ALL) ){
            int err=errno;
            switch(err) {
              case ENOMEM:
                rc = SQLITE_NOMEM;
                break;
              default:
                pFile->lastErrno = err;
                rc = SQLITE_IOERR;
            }
          }



          copyfile_state_free(s);
          close(dstWalFD);
        }
        close(srcWalFD);
      }
      if( rc==SQLITE_OK ){



        /* before we copy, ensure that the file change counter will be modified */
        uint32_t srcChange = 0;
        uint32_t dstChange = 0;
        pread(pSrcFile->h, &srcChange, 4, 24);
        pread(pFile->h, &dstChange, 4, 24);
        







        /* copy the actual database */
        s = copyfile_state_alloc();
        lseek(pSrcFile->h, 0, SEEK_SET);
        lseek(pFile->h, 0, SEEK_SET);
        if( fcopyfile(pSrcFile->h, pFile->h, s, COPYFILE_ALL) ){
          int err=errno;
          switch(err) {
            case ENOMEM:
              rc = SQLITE_NOMEM;
              break;
            default:
              pFile->lastErrno = err;
              rc = SQLITE_IOERR;
          }
        }
        copyfile_state_free(s);


        
        if (srcChange == dstChange) {
          /* modify the change counter to force page zero to be reloaded */
          dstChange ++;
          pwrite(pFile->h, &dstChange, 4, 24);
        }
      }

      if( isSrcCorrupt ){
        sqlite3demo_superunlock_corrupt(src_file, corruptSrcFileLock);
      }else{
        /* done with the source db so end the transaction */
        sqlite3_exec(srcdb2, "COMMIT", 0, 0, 0);
      }
      /* zero out any old journal clutter */
      if( rc==SQLITE_OK ){
        char jPath[MAXPATHLEN+9];
        int zLen = strlcpy(jPath, pFile->zPath, MAXPATHLEN+9);
        if( zLen<MAXPATHLEN ){
          size_t jLen;
          const char extensions[2][9] = { "-wal", "-journal" /* "-shm" */ };
          int j = (srcWalFD<0)?0:1; /* skip the wal if we replaced it */
          for( ; j<2; j++ ){
            jLen = strlcpy(&jPath[zLen], extensions[j], 9);
            if( jLen < 9 ){
              int jfd = open(jPath, O_TRUNC);

              if( jfd==(-1) ){
                if ( errno!=ENOENT ){
                  perror(jPath);
                }
              } else {
                fsync(jfd);
                close(jfd);
              }
            }


          }

        }
        pFile->pMethod->xSync(id, SQLITE_SYNC_FULL);
      }



      



    end_replace_database:
      if( pSrcBtree ){
        sqlite3_close(srcdb2);
        sqlite3BtreeLeave(pSrcBtree);
      }


      sqlite3_mutex_leave(srcdb->mutex);
      if( isDstCorrupt ){
        sqlite3demo_superunlock_corrupt(id, corruptDstFileLock);
      }else{
        sqlite3demo_superunlock(pLock);
      }
      return rc;
    }
#endif /* (SQLITE_ENABLE_APPLE_SPI>0) && defined(__APPLE__) */
    case SQLITE_FCNTL_SYNC_OMITTED: {
      return SQLITE_OK;  /* A no-op */
    }
................................................................................
      p->h = -1;
    }
    p->pInode->pShmNode = 0;
    sqlite3_free(p);
  }
}


static const char *proxySharedMemoryBasePath(unixFile *);

/*
** Open a shared-memory area associated with open database file pDbFd.  
** This particular implementation uses mmapped files.
**
** The file used to implement shared-memory is in the same directory
................................................................................
      /* Check to see if another process is holding the dead-man switch.
      ** If not, truncate the file to zero length. 
      */
      rc = SQLITE_OK;
      if( unixShmSystemLock(pShmNode, F_WRLCK, UNIX_SHM_DMS, 1)==SQLITE_OK ){
        if( robust_ftruncate(pShmNode->h, 0) ){
          rc = unixLogError(SQLITE_IOERR_SHMOPEN, "ftruncate", zShmFilename);
        }else{
          /* If running as root set the uid/gid of the shm file to match the database */
          uid_t euid = geteuid();
          if( euid==0 && (euid!=sStat.st_uid || getegid()!=sStat.st_gid) ){
            if( fchown(pShmNode->h, sStat.st_uid, sStat.st_gid) ){
              rc = SQLITE_IOERR_SHMOPEN;
            }
          }
        }
      }
      if( rc==SQLITE_OK ){
        rc = unixShmSystemLock(pShmNode, F_RDLCK, UNIX_SHM_DMS, 1);
      }
      if( rc ) goto shm_open_err;
    }
................................................................................
** original filename is unavailable.  But 8_3_NAMES is only used for
** FAT filesystems and permissions do not matter there, so just use
** the default permissions.
*/
static int findCreateFileMode(
  const char *zPath,              /* Path of file (possibly) being created */
  int flags,                      /* Flags passed as 4th argument to xOpen() */
  mode_t *pMode,                  /* OUT: Permissions to open file with */
  uid_t *pUid,                    /* OUT: uid to set on the file */
  gid_t *pGid                     /* OUT: gid to set on the file */
){
  int rc = SQLITE_OK;             /* Return Code */
  *pMode = SQLITE_DEFAULT_FILE_PERMISSIONS;
  if( flags & (SQLITE_OPEN_WAL|SQLITE_OPEN_MAIN_JOURNAL) ){
    char zDb[MAX_PATHNAME+1];     /* Database file path */
    int nDb;                      /* Number of valid bytes in zDb */
    struct stat sStat;            /* Output of stat() on database file */
................................................................................
    while( nDb>0 && zPath[nDb]!='-' ) nDb--;
    if( nDb==0 ) return SQLITE_OK;
    memcpy(zDb, zPath, nDb);
    zDb[nDb] = '\0';

    if( 0==stat(zDb, &sStat) ){
      *pMode = sStat.st_mode & 0777;
      *pUid = sStat.st_uid;
      *pGid = sStat.st_gid;
    }else{
      rc = SQLITE_IOERR_FSTAT;
    }
  }else if( flags & SQLITE_OPEN_DELETEONCLOSE ){
    *pMode = 0600;
  }
  return rc;
................................................................................
  int flags,                   /* Input flags to control the opening */
  int *pOutFlags               /* Output flags returned to SQLite core */
){
  unixFile *p = (unixFile *)pFile;
  int fd = -1;                   /* File descriptor returned by open() */
  int dirfd = -1;                /* Directory file descriptor */
  int openFlags = 0;             /* Flags to pass to open() */
#if SQLITE_ENABLE_DATA_PROTECTION
  int eType = flags&0xFF0FFF00;  /* Type of file to open */
#else
  int eType = flags&0xFFFFFF00;  /* Type of file to open */
#endif
  int noLock;                    /* True to omit locking primitives */
  int rc = SQLITE_OK;            /* Function Return Code */

  int isExclusive  = (flags & SQLITE_OPEN_EXCLUSIVE);
  int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);
  int isCreate     = (flags & SQLITE_OPEN_CREATE);
  int isReadonly   = (flags & SQLITE_OPEN_READONLY);
................................................................................
  ** 'conch file' locking functions later on.  */
  if( isReadonly )  openFlags |= O_RDONLY;
  if( isReadWrite ) openFlags |= O_RDWR;
  if( isCreate )    openFlags |= O_CREAT;
  if( isExclusive ) openFlags |= (O_EXCL|O_NOFOLLOW);
  openFlags |= (O_LARGEFILE|O_BINARY);

#if SQLITE_ENABLE_DATA_PROTECTION
  p->protFlags = (flags & SQLITE_OPEN_FILEPROTECTION_MASK);
#endif
    
  if( fd<0 ){
    mode_t openMode;              /* Permissions to create file with */
    uid_t uid;
    gid_t gid;
    rc = findCreateFileMode(zName, flags, &openMode, &uid, &gid);
    if( rc!=SQLITE_OK ){
      assert( !p->pUnused );
      assert( eType==SQLITE_OPEN_WAL || eType==SQLITE_OPEN_MAIN_JOURNAL );
      return rc;
    }
    fd = robust_open(zName, openFlags, openMode);
    OSTRACE(("OPENX   %-3d %s 0%o\n", fd, zName, openFlags));
................................................................................
      openFlags |= O_RDONLY;
      isReadonly = 1;
      fd = robust_open(zName, openFlags, openMode);
    }
    if( fd<0 ){
      rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zName);
      goto open_finished;
    }
    /* if we're opening the wal or journal and running as root, set the journal uid/gid */
    if( !isReadonly && (flags & (SQLITE_OPEN_WAL|SQLITE_OPEN_MAIN_JOURNAL)) ){
      uid_t euid = geteuid();
      if( euid==0 && (euid!=uid || getegid()!=gid) ){
        if( fchown(fd, uid, gid) ){
          rc = SQLITE_CANTOPEN_BKPT;
          goto open_finished;
        }
      }
    }
  }
  assert( fd>=0 );
  if( pOutFlags ){
    *pOutFlags = flags;
  }

................................................................................
    int useProxy = 0;

    /* SQLITE_FORCE_PROXY_LOCKING==1 means force always use proxy, 0 means 
    ** never use proxy, NULL means use proxy for non-local files only.  */
    if( envforce!=NULL ){
      useProxy = atoi(envforce)>0;
    }else{

















      useProxy = !(fsInfo.f_flags&MNT_LOCAL);
    }
    if( useProxy ){
      rc = fillInUnixFile(pVfs, fd, dirfd, pFile, zPath, noLock,
                          isDelete, isReadonly);
      if( rc==SQLITE_OK ){
        /* cache the pMethod in case the transform fails */
................................................................................
      if( fsync(fd)==-1 )
#else
      if( fsync(fd) )
#endif
      {
        rc = unixLogError(SQLITE_IOERR_DIR_FSYNC, "fsync", zPath);
      }
#if OSCLOSE_CHECK_CLOSE_IOERR
      if( close(fd)&&!rc ){
        rc = SQLITE_IOERR_DIR_CLOSE;
      }
#else
      robust_close(0, fd, __LINE__);
#endif
    }
  }
#endif
  return rc;
}

/*
................................................................................
struct proxyLockingContext {
  unixFile *conchFile;         /* Open conch file */
  char *conchFilePath;         /* Name of the conch file */
  unixFile *lockProxy;         /* Open proxy lock file */
  char *lockProxyPath;         /* Name of the proxy lock file */
  char *dbPath;                /* Name of the open file */
  int conchHeld;               /* 1 if the conch is held, -1 if lockless */
  int nFails;                  /* Number of conch taking failures */
  void *oldLockingContext;     /* Original lockingcontext to restore on close */
  sqlite3_io_methods const *pOldMethod;     /* Original I/O methods for close */
};

/* 
** The proxy lock file path for the database at dbPath is written into lPath, 
** which must point to valid, writable memory large enough for a maxLen length
................................................................................

/* get the host ID via gethostuuid(), pHostID must point to PROXY_HOSTIDLEN 
** bytes of writable memory.
*/
static int proxyGetHostID(unsigned char *pHostID, int *pError){
  assert(PROXY_HOSTIDLEN == sizeof(uuid_t));
  memset(pHostID, 0, PROXY_HOSTIDLEN);
#if HAVE_GETHOSTUUID

  {
    struct timespec timeout = {1, 0}; /* 1 sec timeout */
    
    if( gethostuuid(pHostID, &timeout) ){
      int err = errno;
      if( pError ){
        *pError = err;
      }
      return SQLITE_IOERR;
    }
................................................................................
/* Take the requested lock on the conch file and break a stale lock if the 
** host id matches.
*/
static int proxyConchLock(unixFile *pFile, uuid_t myHostID, int lockType){
  proxyLockingContext *pCtx = (proxyLockingContext *)pFile->lockingContext; 
  unixFile *conchFile = pCtx->conchFile;
  int rc = SQLITE_OK;

  struct timespec conchModTime;
  
  do {
    rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, lockType);

    if( rc==SQLITE_BUSY ){
      pCtx->nFails ++;
      /* If the lock failed (busy):
       * 1st try: get the mod time of the conch, wait 0.5s and try again. 
       * 2nd try: fail if the mod time changed or host id is different, wait 
       *           10 sec and try again
       * 3rd try: break the lock unless the mod time has changed.
       */
      struct stat buf;
      if( osFstat(conchFile->h, &buf) ){
        pFile->lastErrno = errno;
        return SQLITE_IOERR_LOCK;
      }
      
      if( pCtx->nFails==1 ){
        conchModTime = buf.st_mtimespec;
        usleep(500000); /* wait 0.5 sec and try the lock again*/
        continue;  
      }

      assert( pCtx->nFails>1 );
      if( conchModTime.tv_sec != buf.st_mtimespec.tv_sec || 
         conchModTime.tv_nsec != buf.st_mtimespec.tv_nsec ){
        return SQLITE_BUSY;
      }
      
      if( pCtx->nFails==2 ){  
        char tBuf[PROXY_MAXCONCHLEN];
        int len = osPread(conchFile->h, tBuf, PROXY_MAXCONCHLEN, 0);
        if( len<0 ){
          pFile->lastErrno = errno;
          return SQLITE_IOERR_LOCK;
        }
        if( len>PROXY_PATHINDEX && tBuf[0]==(char)PROXY_CONCHVERSION){
          /* don't break the lock if the host id doesn't match, but do log
           * an error to console so users can diagnose stale NFS locks more 
           * easily 
           */
          if( 0!=memcmp(&tBuf[PROXY_HEADERLEN], myHostID, PROXY_HOSTIDLEN) ){
            uuid_t conchUUID;
            uuid_string_t conchUUIDString;
            uuid_string_t myUUIDString;
            assert(PROXY_HOSTIDLEN == sizeof(uuid_t));
            memcpy(conchUUID, &tBuf[PROXY_HEADERLEN], PROXY_HOSTIDLEN);
            uuid_unparse(conchUUID, conchUUIDString);
            uuid_unparse(myHostID, myUUIDString);
            fprintf(stderr, "ERROR: sqlite database is locked because it is in use "
                    "by another host that holds a host-exclusive lock on %s; "
                    "this host (UUID %s) cannot override the host-exclusive lock "
                    "until the other host (UUID %s) releases its locks on %s\n", 
                    pFile->zPath, myUUIDString, conchUUIDString, conchFile->zPath);
            return SQLITE_BUSY;
          }
        }else{
          /* don't break the lock on short read or a version mismatch */
          return SQLITE_BUSY;
        }
        usleep(10000000); /* wait 10 sec and try the lock again */
        continue; 
      }
      
      assert( pCtx->nFails>=3 );
      if( (pCtx->nFails==3)&&(0==proxyBreakConchLock(pFile, myHostID)) ){
        rc = SQLITE_OK;
        if( lockType==EXCLUSIVE_LOCK ){
          rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, SHARED_LOCK);          
        }
        if( !rc ){
          rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, lockType);
        }
      }
    }
  } while( rc==SQLITE_BUSY && pCtx->nFails<3 );
  
  return rc;
}

/* Takes the conch by taking a shared lock and read the contents conch, if 
** lockPath is non-NULL, the host ID and lock file path must match.  A NULL 
** lockPath means that the lockPath in the conch file will be used if the 
................................................................................
          /* We are trying for an exclusive lock but another thread in this
           ** same process is still holding a shared lock. */
          rc = SQLITE_BUSY;
        } else {          
          rc = proxyConchLock(pFile, myHostID, EXCLUSIVE_LOCK);
        }
      }else{
        rc = proxyConchLock(pFile, myHostID, EXCLUSIVE_LOCK);
      }
      if( rc==SQLITE_OK ){
        char writeBuffer[PROXY_MAXCONCHLEN];
        int writeSize = 0;
        
        writeBuffer[0] = (char)PROXY_CONCHVERSION;
        memcpy(&writeBuffer[PROXY_HEADERLEN], myHostID, PROXY_HOSTIDLEN);
................................................................................
      }
      conchFile->pMethod->xUnlock((sqlite3_file*)conchFile, SHARED_LOCK);
      
    end_takeconch:
      OSTRACE(("TRANSPROXY: CLOSE  %d\n", pFile->h));
      if( rc==SQLITE_OK && pFile->openFlags ){
        if( pFile->h>=0 ){
#if defined(STRICT_CLOSE_ERROR) && OSCLOSE_CHECK_CLOSE_IOERR
          if( close(pFile->h) ){
            pFile->lastErrno = errno;
            return SQLITE_IOERR_CLOSE;
          }
#else
          robust_close(pFile, pFile->h, __LINE__);
#endif
        }
        pFile->h = -1;
        int fd = robust_open(pCtx->dbPath, pFile->openFlags,
                      SQLITE_DEFAULT_FILE_PERMISSIONS);
        OSTRACE(("TRANSPROXY: OPEN  %d\n", fd));
        if( fd>=0 ){
          pFile->h = fd;

  ** If successful, open the master journal file for reading.
  */
  pMaster = (sqlite3_file *)sqlite3MallocZero(pVfs->szOsFile * 2);
  pJournal = (sqlite3_file *)(((u8 *)pMaster) + pVfs->szOsFile);
  if( !pMaster ){
    rc = SQLITE_NOMEM;
  }else{




    const int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_MASTER_JOURNAL);
    rc = sqlite3OsOpen(pVfs, zMaster, pMaster, flags, 0);
  }
  if( rc!=SQLITE_OK ) goto delmaster_out;

  /* Load the entire master journal file into space obtained from
  ** sqlite3_malloc() and pointed to by zMasterJournal.   Also obtain
  ** sufficient space (in zMasterPtr) to hold the names of master
................................................................................
    }
    if( exists ){
      /* One of the journals pointed to by the master journal exists.
      ** Open it and check if it points at the master journal. If
      ** so, return without deleting the master journal file.
      */
      int c;




      int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_MAIN_JOURNAL);
      rc = sqlite3OsOpen(pVfs, zJournal, pJournal, flags, 0);
      if( rc!=SQLITE_OK ){
        goto delmaster_out;
      }

      rc = readMasterJournal(pJournal, zMasterPtr, nMasterPtr);
      sqlite3OsClose(pJournal);
................................................................................
){
  int rc;               /* Return code */

#ifdef SQLITE_TEST
  sqlite3_opentemp_count++;  /* Used for testing and analysis only */
#endif





  vfsFlags |=  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE |
            SQLITE_OPEN_EXCLUSIVE | SQLITE_OPEN_DELETEONCLOSE;
  rc = sqlite3OsOpen(pPager->pVfs, 0, pFile, vfsFlags, 0);
  assert( rc!=SQLITE_OK || isOpen(pFile) );
  return rc;
}

/*
................................................................................
  pPager->changeCountDone = pPager->tempFile;
  pPager->memDb = (u8)memDb;
  pPager->readOnly = (u8)readOnly;
  assert( useJournal || pPager->tempFile );
  pPager->noSync = pPager->tempFile;
  pPager->fullSync = pPager->noSync ?0:1;
  pPager->syncFlags = pPager->noSync ? 0 : SQLITE_SYNC_NORMAL;



  pPager->ckptSyncFlags = pPager->syncFlags;

  /* pPager->pFirst = 0; */
  /* pPager->pFirstSynced = 0; */
  /* pPager->pLast = 0; */
  pPager->nExtra = (u16)nExtra;
  pPager->journalSizeLimit = SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT;
  assert( isOpen(pPager->fd) || tempFile );
  setSectorSize(pPager);
................................................................................
          /* The journal file exists and no other connection has a reserved
          ** or greater lock on the database file. Now check that there is
          ** at least one non-zero bytes at the start of the journal file.
          ** If there is, then we consider this journal to be hot. If not, 
          ** it can be ignored.
          */
          if( !jrnlOpen ){




            int f = SQLITE_OPEN_READONLY|SQLITE_OPEN_MAIN_JOURNAL;
            rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, f, &f);
          }
          if( rc==SQLITE_OK ){
            u8 first = 0;
            rc = sqlite3OsRead(pPager->jfd, (void *)&first, 1, 0);
            if( rc==SQLITE_IOERR_SHORT_READ ){
              rc = SQLITE_OK;
................................................................................
      if( !isOpen(pPager->jfd) ){
        sqlite3_vfs * const pVfs = pPager->pVfs;
        int bExists;              /* True if journal file exists */
        rc = sqlite3OsAccess(
            pVfs, pPager->zJournal, SQLITE_ACCESS_EXISTS, &bExists);
        if( rc==SQLITE_OK && bExists ){
          int fout = 0;




          int f = SQLITE_OPEN_READWRITE|SQLITE_OPEN_MAIN_JOURNAL;
          assert( !pPager->tempFile );
          rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, f, &fout);
          assert( rc!=SQLITE_OK || isOpen(pPager->jfd) );
          if( rc==SQLITE_OK && fout&SQLITE_OPEN_READONLY ){
            rc = SQLITE_CANTOPEN_BKPT;
            sqlite3OsClose(pPager->jfd);
          }
................................................................................
  
    /* Open the journal file if it is not already open. */
    if( !isOpen(pPager->jfd) ){
      if( pPager->journalMode==PAGER_JOURNALMODE_MEMORY ){
        sqlite3MemJournalOpen(pPager->jfd);
      }else{
        const int flags =                   /* VFS flags to open journal file */



          SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|
          (pPager->tempFile ? 
            (SQLITE_OPEN_DELETEONCLOSE|SQLITE_OPEN_TEMP_JOURNAL):
            (SQLITE_OPEN_MAIN_JOURNAL)
          );
  #ifdef SQLITE_ENABLE_ATOMIC_WRITE
        rc = sqlite3JournalOpen(
................................................................................
    rc = pagerExclusiveLock(pPager);
  }

  /* Open the connection to the log file. If this operation fails, 
  ** (e.g. due to malloc() failure), return an error code.
  */
  if( rc==SQLITE_OK ){

    rc = sqlite3WalOpen(pPager->pVfs, 



        pPager->fd, pPager->zWal, pPager->exclusiveMode,
        pPager->journalSizeLimit, &pPager->pWal
    );

  }

  return rc;
}


/*

  ** If successful, open the master journal file for reading.
  */
  pMaster = (sqlite3_file *)sqlite3MallocZero(pVfs->szOsFile * 2);
  pJournal = (sqlite3_file *)(((u8 *)pMaster) + pVfs->szOsFile);
  if( !pMaster ){
    rc = SQLITE_NOMEM;
  }else{
    const int flags = 
#if SQLITE_ENABLE_DATA_PROTECTION
      (pPager->vfsFlags&SQLITE_OPEN_FILEPROTECTION_MASK)|
#endif
      (SQLITE_OPEN_READONLY|SQLITE_OPEN_MASTER_JOURNAL);
    rc = sqlite3OsOpen(pVfs, zMaster, pMaster, flags, 0);
  }
  if( rc!=SQLITE_OK ) goto delmaster_out;

  /* Load the entire master journal file into space obtained from
  ** sqlite3_malloc() and pointed to by zMasterJournal.   Also obtain
  ** sufficient space (in zMasterPtr) to hold the names of master
................................................................................
    }
    if( exists ){
      /* One of the journals pointed to by the master journal exists.
      ** Open it and check if it points at the master journal. If
      ** so, return without deleting the master journal file.
      */
      int c;
      int flags = 
#if SQLITE_ENABLE_DATA_PROTECTION
        (pPager->vfsFlags&SQLITE_OPEN_FILEPROTECTION_MASK)|
#endif
        (SQLITE_OPEN_READONLY|SQLITE_OPEN_MAIN_JOURNAL);
      rc = sqlite3OsOpen(pVfs, zJournal, pJournal, flags, 0);
      if( rc!=SQLITE_OK ){
        goto delmaster_out;
      }

      rc = readMasterJournal(pJournal, zMasterPtr, nMasterPtr);
      sqlite3OsClose(pJournal);
................................................................................
){
  int rc;               /* Return code */

#ifdef SQLITE_TEST
  sqlite3_opentemp_count++;  /* Used for testing and analysis only */
#endif

  vfsFlags |=  
#if SQLITE_ENABLE_DATA_PROTECTION
            (pPager->vfsFlags&SQLITE_OPEN_FILEPROTECTION_MASK)|
#endif
            SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE |
            SQLITE_OPEN_EXCLUSIVE | SQLITE_OPEN_DELETEONCLOSE;
  rc = sqlite3OsOpen(pPager->pVfs, 0, pFile, vfsFlags, 0);
  assert( rc!=SQLITE_OK || isOpen(pFile) );
  return rc;
}

/*
................................................................................
  pPager->changeCountDone = pPager->tempFile;
  pPager->memDb = (u8)memDb;
  pPager->readOnly = (u8)readOnly;
  assert( useJournal || pPager->tempFile );
  pPager->noSync = pPager->tempFile;
  pPager->fullSync = pPager->noSync ?0:1;
  pPager->syncFlags = pPager->noSync ? 0 : SQLITE_SYNC_NORMAL;
#if SQLITE_DEFAULT_CKPTFULLFSYNC
  pPager->ckptSyncFlags = pPager->noSync ? 0 : SQLITE_SYNC_FULL;
#else
  pPager->ckptSyncFlags = pPager->syncFlags;
#endif
  /* pPager->pFirst = 0; */
  /* pPager->pFirstSynced = 0; */
  /* pPager->pLast = 0; */
  pPager->nExtra = (u16)nExtra;
  pPager->journalSizeLimit = SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT;
  assert( isOpen(pPager->fd) || tempFile );
  setSectorSize(pPager);
................................................................................
          /* The journal file exists and no other connection has a reserved
          ** or greater lock on the database file. Now check that there is
          ** at least one non-zero bytes at the start of the journal file.
          ** If there is, then we consider this journal to be hot. If not, 
          ** it can be ignored.
          */
          if( !jrnlOpen ){
            int f = 
#if SQLITE_ENABLE_DATA_PROTECTION
              (pPager->vfsFlags&SQLITE_OPEN_FILEPROTECTION_MASK)|
#endif
              SQLITE_OPEN_READONLY|SQLITE_OPEN_MAIN_JOURNAL;
            rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, f, &f);
          }
          if( rc==SQLITE_OK ){
            u8 first = 0;
            rc = sqlite3OsRead(pPager->jfd, (void *)&first, 1, 0);
            if( rc==SQLITE_IOERR_SHORT_READ ){
              rc = SQLITE_OK;
................................................................................
      if( !isOpen(pPager->jfd) ){
        sqlite3_vfs * const pVfs = pPager->pVfs;
        int bExists;              /* True if journal file exists */
        rc = sqlite3OsAccess(
            pVfs, pPager->zJournal, SQLITE_ACCESS_EXISTS, &bExists);
        if( rc==SQLITE_OK && bExists ){
          int fout = 0;
          int f = 
#if SQLITE_ENABLE_DATA_PROTECTION
            (pPager->vfsFlags&SQLITE_OPEN_FILEPROTECTION_MASK)|
#endif
            SQLITE_OPEN_READWRITE|SQLITE_OPEN_MAIN_JOURNAL;
          assert( !pPager->tempFile );
          rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, f, &fout);
          assert( rc!=SQLITE_OK || isOpen(pPager->jfd) );
          if( rc==SQLITE_OK && fout&SQLITE_OPEN_READONLY ){
            rc = SQLITE_CANTOPEN_BKPT;
            sqlite3OsClose(pPager->jfd);
          }
................................................................................
  
    /* Open the journal file if it is not already open. */
    if( !isOpen(pPager->jfd) ){
      if( pPager->journalMode==PAGER_JOURNALMODE_MEMORY ){
        sqlite3MemJournalOpen(pPager->jfd);
      }else{
        const int flags =                   /* VFS flags to open journal file */
#if SQLITE_ENABLE_DATA_PROTECTION
          (pPager->vfsFlags&SQLITE_OPEN_FILEPROTECTION_MASK)|
#endif
          SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|
          (pPager->tempFile ? 
            (SQLITE_OPEN_DELETEONCLOSE|SQLITE_OPEN_TEMP_JOURNAL):
            (SQLITE_OPEN_MAIN_JOURNAL)
          );
  #ifdef SQLITE_ENABLE_ATOMIC_WRITE
        rc = sqlite3JournalOpen(
................................................................................
    rc = pagerExclusiveLock(pPager);
  }

  /* Open the connection to the log file. If this operation fails, 
  ** (e.g. due to malloc() failure), return an error code.
  */
  if( rc==SQLITE_OK ){
#if SQLITE_ENABLE_DATA_PROTECTION
    rc = sqlite3WalOpen(pPager->pVfs, pPager->fd, pPager->zWal, pPager->exclusiveMode,
        pPager->journalSizeLimit, (pPager->vfsFlags & SQLITE_OPEN_FILEPROTECTION_MASK), 
        &pPager->pWal);
#else
    rc = sqlite3WalOpen(pPager->pVfs, pPager->fd, pPager->zWal, pPager->exclusiveMode,
        pPager->journalSizeLimit, 0, &pPager->pWal);

#endif
  }

  return rc;
}


/*

    assert( pBt!=0 );
    if( zRight ){
      b = sqlite3GetBoolean(zRight);
    }
    if( pId2->n==0 && b>=0 ){
      int ii;
      for(ii=0; ii<db->nDb; ii++){
        sqlite3BtreeSecureDelete(db->aDb[ii].pBt, b);
      }
    }
    b = sqlite3BtreeSecureDelete(pBt, b);
    returnSingleInt(pParse, "secure_delete", &b);
  }else

  /*
  **  PRAGMA [database.]max_page_count
  **  PRAGMA [database.]max_page_count=N
  **
................................................................................
      }
    }
    if( eMode==PAGER_JOURNALMODE_QUERY && pId2->n==0 ){
      /* Convert "PRAGMA journal_mode" into "PRAGMA main.journal_mode" */
      iDb = 0;
      pId2->n = 1;
    }








    for(ii=db->nDb-1; ii>=0; ii--){
      if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){
        sqlite3VdbeUsesBtree(v, ii);
        sqlite3VdbeAddOp3(v, OP_JournalMode, ii, 1, eMode);
      }
    }
    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);

    assert( pBt!=0 );
    if( zRight ){
      b = sqlite3GetBoolean(zRight);
    }
    if( pId2->n==0 && b>=0 ){
      int ii;
      for(ii=0; ii<db->nDb; ii++){
        sqlite3BtreeSecureDelete(db->aDb[ii].pBt, (int)b);
      }
    }
    b = (int)sqlite3BtreeSecureDelete(pBt, (int)b);
    returnSingleInt(pParse, "secure_delete", &b);
  }else

  /*
  **  PRAGMA [database.]max_page_count
  **  PRAGMA [database.]max_page_count=N
  **
................................................................................
      }
    }
    if( eMode==PAGER_JOURNALMODE_QUERY && pId2->n==0 ){
      /* Convert "PRAGMA journal_mode" into "PRAGMA main.journal_mode" */
      iDb = 0;
      pId2->n = 1;
    }
#ifdef SQLITE_DEFAULT_WAL_SAFETYLEVEL
    if (eMode == PAGER_JOURNALMODE_WAL) {
      /* when entering wal mode, immediately switch the safety_level
       * so that a query to pragma synchronous returns the correct value
       */
      pDb->safety_level = SQLITE_DEFAULT_WAL_SAFETYLEVEL;
    }
#endif /* SQLITE_DEFAULT_WAL_SAFETYLEVEL */
    for(ii=db->nDb-1; ii>=0; ii--){
      if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){
        sqlite3VdbeUsesBtree(v, ii);
        sqlite3VdbeAddOp3(v, OP_JournalMode, ii, 1, eMode);
      }
    }
    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);

  sqlite3DbFree(db, sAggInfo.aCol);
  sqlite3DbFree(db, sAggInfo.aFunc);
  return rc;
}

#if defined(SQLITE_DEBUG)



/*
*******************************************************************************
** The following code is used for testing and debugging only.  The code
** that follows does not appear in normal builds.
**
** These routines are used to print out the content of all or part of a 
** parse structures such as Select or Expr.  Such printouts are useful

  sqlite3DbFree(db, sAggInfo.aCol);
  sqlite3DbFree(db, sAggInfo.aFunc);
  return rc;
}

#if defined(SQLITE_DEBUG)
void sqlite3PrintExpr(Expr *p);
void sqlite3PrintExprList(ExprList *pList);
void sqlite3PrintSelect(Select *p, int indent);
/*
*******************************************************************************
** The following code is used for testing and debugging only.  The code
** that follows does not appear in normal builds.
**
** These routines are used to print out the content of all or part of a 
** parse structures such as Select or Expr.  Such printouts are useful

** would generate warning messages when they were used.  But that
** compiler magic ended up generating such a flurry of bug reports
** that we have taken it all out and gone back to using simple
** noop macros.
*/
#define SQLITE_DEPRECATED
#define SQLITE_EXPERIMENTAL




/*
** Ensure these symbols were not defined by some previous header file.
*/
#ifdef SQLITE_VERSION
# undef SQLITE_VERSION
#endif
................................................................................
#define SQLITE_OPEN_SUBJOURNAL       0x00002000  /* VFS only */
#define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */
#define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_WAL              0x00080000  /* VFS only */


/* Reserved:                         0x00F00000 */

/*
** CAPI3REF: Device Characteristics
**
** The xDeviceCharacteristics method of the [sqlite3_io_methods]
................................................................................
** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
** successfully.  An [error code] is returned otherwise.)^
**
** ^Shared cache is disabled by default. But this might change in
** future releases of SQLite.  Applications that care about shared
** cache setting should set it explicitly.
**





** See Also:  [SQLite Shared-Cache Mode]
*/
int sqlite3_enable_shared_cache(int);

/*
** CAPI3REF: Attempt To Free Heap Memory
**
** ^The sqlite3_release_memory() interface attempts to free N bytes
** of heap memory by deallocating non-essential memory allocations
** held by the database library.   Memory used to cache database

** would generate warning messages when they were used.  But that
** compiler magic ended up generating such a flurry of bug reports
** that we have taken it all out and gone back to using simple
** noop macros.
*/
#define SQLITE_DEPRECATED
#define SQLITE_EXPERIMENTAL
#ifndef __OSX_AVAILABLE_BUT_DEPRECATED
#define __OSX_AVAILABLE_BUT_DEPRECATED(MacOSAvailable, MacOSDeprecated, iPhoneOSAvailable, iPhoneOSDeprecated)
#endif

/*
** Ensure these symbols were not defined by some previous header file.
*/
#ifdef SQLITE_VERSION
# undef SQLITE_VERSION
#endif
................................................................................
#define SQLITE_OPEN_SUBJOURNAL       0x00002000  /* VFS only */
#define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */
#define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_WAL              0x00080000  /* VFS only */
#define SQLITE_OPEN_FILEPROTECTION_MASK                                 0x00700000

/* Reserved:                         0x00F00000 */

/*
** CAPI3REF: Device Characteristics
**
** The xDeviceCharacteristics method of the [sqlite3_io_methods]
................................................................................
** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
** successfully.  An [error code] is returned otherwise.)^
**
** ^Shared cache is disabled by default. But this might change in
** future releases of SQLite.  Applications that care about shared
** cache setting should set it explicitly.
**
** ^Note: This method is deprecated on MacOS X 10.7 and iOS version 5.0
** and will always return SQLITE_MISUSE, instead of calling this function
** shared cache mode should be enabled per-database connection via 
** sqlite3_open_v2 with SQLITE_OPEN_SHAREDCACHE instead.
**
** See Also:  [SQLite Shared-Cache Mode]
*/
int sqlite3_enable_shared_cache(int) __OSX_AVAILABLE_BUT_DEPRECATED(__MAC_10_0, __MAC_10_7, __IPHONE_2_0, __IPHONE_5_0);

/*
** CAPI3REF: Attempt To Free Heap Memory
**
** ^The sqlite3_release_memory() interface attempts to free N bytes
** of heap memory by deallocating non-essential memory allocations
** held by the database library.   Memory used to cache database

/*
 *  sqlite3_private.h
 */

#ifndef _SQLITE3_PRIVATE_H
#define _SQLITE3_PRIVATE_H























/*
** Pass the SQLITE_TRUNCATE_DATABASE operation code to sqlite3_file_control() 
** to truncate a database and its associated journal file to zero length.
*/
#define SQLITE_TRUNCATE_DATABASE      101

/*

/*
 *  sqlite3_private.h
 */

#ifndef _SQLITE3_PRIVATE_H
#define _SQLITE3_PRIVATE_H

#define SQLITE_LOCKSTATE_OFF    0
#define SQLITE_LOCKSTATE_ON     1
#define SQLITE_LOCKSTATE_NOTADB 2
#define SQLITE_LOCKSTATE_ERROR  -1

#define SQLITE_LOCKSTATE_ANYPID -1

/* 
** Test a file path for sqlite locks held by a process ID (-1 = any PID). 
** Returns one of the following integer codes:
** 
**   SQLITE_LOCKSTATE_OFF    no active sqlite file locks match the specified pid
**   SQLITE_LOCKSTATE_ON     active sqlite file locks match the specified pid
**   SQLITE_LOCKSTATE_NOTADB path points to a file that is not an sqlite db file
**   SQLITE_LOCKSTATE_ERROR  path was not vaild or was unreadable
**
** There is no support for identifying db files encrypted via SEE encryption
** currently.  Zero byte files are tested for sqlite locks, but if no sqlite 
** locks are present then SQLITE_LOCKSTATE_NOTADB is returned.
*/
extern int _sqlite3_lockstate(const char *path, pid_t pid);

/*
** Pass the SQLITE_TRUNCATE_DATABASE operation code to sqlite3_file_control() 
** to truncate a database and its associated journal file to zero length.
*/
#define SQLITE_TRUNCATE_DATABASE      101

/*

    Tcl_AppendResult(interp, "Unexpected non-zero errno: ",
                     Tcl_GetStringFromObj(Tcl_NewIntObj(iArg), 0), " ", 0);
    return TCL_ERROR;
  }
  return TCL_OK;  
}














































































/*
** tclcmd:   file_control_chunksize_test DB DBNAME SIZE
**
** This TCL command runs the sqlite3_file_control interface and
** verifies correct operation of the SQLITE_GET_LOCKPROXYFILE and
** SQLITE_SET_LOCKPROXYFILE verbs.
*/
................................................................................
     { "vfs_unlink_test",            vfs_unlink_test,     0   },
     { "vfs_initfail_test",          vfs_initfail_test,   0   },
     { "vfs_unregister_all",         vfs_unregister_all,  0   },
     { "vfs_reregister_all",         vfs_reregister_all,  0   },
     { "file_control_test",          file_control_test,   0   },
     { "file_control_lasterrno_test", file_control_lasterrno_test,  0   },
     { "file_control_lockproxy_test", file_control_lockproxy_test,  0   },




     { "file_control_chunksize_test", file_control_chunksize_test,  0   },
     { "file_control_sizehint_test", file_control_sizehint_test,  0   },
     { "sqlite3_vfs_list",           vfs_list,     0   },
     { "sqlite3_create_function_v2", test_create_function_v2, 0 },
     { "path_is_local",              path_is_local,  0   },
     { "path_is_dos",                path_is_dos,  0   },

    Tcl_AppendResult(interp, "Unexpected non-zero errno: ",
                     Tcl_GetStringFromObj(Tcl_NewIntObj(iArg), 0), " ", 0);
    return TCL_ERROR;
  }
  return TCL_OK;  
}

#ifdef __APPLE__
/* From sqlite3_priavet.h */
# ifndef SQLITE_TRUNCATE_DATABASE
# define SQLITE_TRUNCATE_DATABASE      101
# endif
# ifndef SQLITE_REPLACE_DATABASE
# define SQLITE_REPLACE_DATABASE       102
# endif

/*
** tclcmd:   file_control_truncate_test DB
**
** This TCL command runs the sqlite3_file_control interface and
** verifies correct operation of the SQLITE_TRUNCATE_DATABASE verb.
*/
static int file_control_truncate_test(
  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  sqlite3 *db;
  int rc;
  
  if( objc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"",
                     Tcl_GetStringFromObj(objv[0], 0), " DB", 0);
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ){
    return TCL_ERROR;
  }
  rc = sqlite3_file_control(db, NULL, SQLITE_TRUNCATE_DATABASE, 0);
  if( rc ){ 
    Tcl_SetObjResult(interp, Tcl_NewIntObj(rc)); 
    return TCL_ERROR; 
  }
  return TCL_OK;  
}

/*
** tclcmd:   file_control_replace_test DB
**
** This TCL command runs the sqlite3_file_control interface and
** verifies correct operation of the SQLITE_REPLACE_DATABASE verb.
*/
static int file_control_replace_test(
  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  int iArg = 0;
  sqlite3 *src_db;
  sqlite3 *dst_db;
  int rc;
  
  if( objc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"",
                     Tcl_GetStringFromObj(objv[0], 0), " DST_DB SRC_DB", 0);
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &dst_db) ){
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[2]), &src_db) ){
    return TCL_ERROR;
  }
  rc = sqlite3_file_control(dst_db, NULL, SQLITE_REPLACE_DATABASE, src_db);
  if( rc ){ 
    Tcl_SetObjResult(interp, Tcl_NewIntObj(rc)); 
    return TCL_ERROR; 
  }
  return TCL_OK;  
}
#endif /* __APPLE__ */

/*
** tclcmd:   file_control_chunksize_test DB DBNAME SIZE
**
** This TCL command runs the sqlite3_file_control interface and
** verifies correct operation of the SQLITE_GET_LOCKPROXYFILE and
** SQLITE_SET_LOCKPROXYFILE verbs.
*/
................................................................................
     { "vfs_unlink_test",            vfs_unlink_test,     0   },
     { "vfs_initfail_test",          vfs_initfail_test,   0   },
     { "vfs_unregister_all",         vfs_unregister_all,  0   },
     { "vfs_reregister_all",         vfs_reregister_all,  0   },
     { "file_control_test",          file_control_test,   0   },
     { "file_control_lasterrno_test", file_control_lasterrno_test,  0   },
     { "file_control_lockproxy_test", file_control_lockproxy_test,  0   },
#ifdef __APPLE__
     { "file_control_truncate_test", file_control_truncate_test,  0   },
     { "file_control_replace_test", file_control_replace_test,  0   },
#endif 
     { "file_control_chunksize_test", file_control_chunksize_test,  0   },
     { "file_control_sizehint_test", file_control_sizehint_test,  0   },
     { "sqlite3_vfs_list",           vfs_list,     0   },
     { "sqlite3_create_function_v2", test_create_function_v2, 0 },
     { "path_is_local",              path_is_local,  0   },
     { "path_is_dos",                path_is_dos,  0   },

  Tcl_SetVar2(interp,"sqlite_options","lock_proxy_pragmas","0",TCL_GLOBAL_ONLY);
#endif
#if defined(SQLITE_PREFER_PROXY_LOCKING) && defined(__APPLE__)
  Tcl_SetVar2(interp,"sqlite_options","prefer_proxy_locking","1",TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp,"sqlite_options","prefer_proxy_locking","0",TCL_GLOBAL_ONLY);
#endif
    











    
#ifdef SQLITE_OMIT_SHARED_CACHE
  Tcl_SetVar2(interp, "sqlite_options", "shared_cache", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "shared_cache", "1", TCL_GLOBAL_ONLY);
#endif

  Tcl_SetVar2(interp,"sqlite_options","lock_proxy_pragmas","0",TCL_GLOBAL_ONLY);
#endif
#if defined(SQLITE_PREFER_PROXY_LOCKING) && defined(__APPLE__)
  Tcl_SetVar2(interp,"sqlite_options","prefer_proxy_locking","1",TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp,"sqlite_options","prefer_proxy_locking","0",TCL_GLOBAL_ONLY);
#endif

#if SQLITE_DEFAULT_CKPTFULLFSYNC
  Tcl_SetVar2(interp,"sqlite_options","default_ckptfullfsync","1",TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp,"sqlite_options","default_ckptfullfsync","0",TCL_GLOBAL_ONLY);
#endif
#if SQLITE_DEFAULT_WAL_SAFETYLEVEL
  Tcl_SetVar2(interp,"sqlite_options","default_wal_safetylevel",
              STRINGVALUE(SQLITE_DEFAULT_WAL_SAFETYLEVEL),TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp,"sqlite_options","default_wal_safetylevel","0",TCL_GLOBAL_ONLY);
#endif
    
#ifdef SQLITE_OMIT_SHARED_CACHE
  Tcl_SetVar2(interp, "sqlite_options", "shared_cache", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "shared_cache", "1", TCL_GLOBAL_ONLY);
#endif

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing all sorts of SQLite interfaces. This code
** is not included in the SQLite library. 
*/

#include <sqlite3.h>

/* Solely for the UNUSED_PARAMETER() macro. */
#include "sqliteInt.h"

/* 
** Type used to cache parameter information for the "circle" r-tree geometry
** callback.

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing all sorts of SQLite interfaces. This code
** is not included in the SQLite library. 
*/

#include "sqlite3.h"

/* Solely for the UNUSED_PARAMETER() macro. */
#include "sqliteInt.h"

/* 
** Type used to cache parameter information for the "circle" r-tree geometry
** callback.

** mode database files. The interface to the example code in this file 
** consists of the following two functions:
**
**   sqlite3demo_superlock()
**   sqlite3demo_superunlock()
*/

#include <sqlite3.h>
#include <string.h>               /* memset(), strlen() */
#include <assert.h>               /* assert() */

/*
** A structure to collect a busy-handler callback and argument and a count
** of the number of times it has been invoked.
*/
................................................................................
}

/*
** Release a superlock held on a database file. The argument passed to 
** this function must have been obtained from a successful call to
** sqlite3demo_superlock().
*/
void sqlite3demo_superunlock(void *pLock){
  Superlock *p = (Superlock *)pLock;
  if( p->bWal ){
    int rc;                         /* Return code */
    int flags = SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE;
    sqlite3_file *fd = 0;
    rc = sqlite3_file_control(p->db, "main", SQLITE_FCNTL_FILE_POINTER, (void *)&fd);
    if( rc==SQLITE_OK ){
................................................................................
**
** If a required lock cannot be obtained immediately and the xBusy parameter
** to this function is not NULL, then xBusy is invoked in the same way
** as a busy-handler registered with SQLite (using sqlite3_busy_handler())
** until either the lock can be obtained or the busy-handler function returns
** 0 (indicating "give up").
*/
int sqlite3demo_superlock(
  const char *zPath,              /* Path to database file to lock */
  const char *zVfs,               /* VFS to use to access database file */

  int (*xBusy)(void*,int),        /* Busy handler callback */
  void *pBusyArg,                 /* Context arg for busy handler */
  void **ppLock                   /* OUT: Context to pass to superunlock() */
){
  SuperlockBusy busy = {0, 0, 0}; /* Busy handler wrapper object */
  int rc;                         /* Return code */
  Superlock *pLock;
................................................................................

  pLock = sqlite3_malloc(sizeof(Superlock));
  if( !pLock ) return SQLITE_NOMEM;
  memset(pLock, 0, sizeof(Superlock));

  /* Open a database handle on the file to superlock. */
  rc = sqlite3_open_v2(
      zPath, &pLock->db, SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE, zVfs
  );

  /* Install a busy-handler and execute a BEGIN EXCLUSIVE. If this is not
  ** a WAL database, this is all we need to do.  
  **
  ** A wrapper function is used to invoke the busy-handler instead of
  ** registering the busy-handler function supplied by the user directly
................................................................................
  }
  if( objc>4 ){
    busy.interp = interp;
    busy.pScript = objv[4];
    xBusy = superlock_busy;
  }

  rc = sqlite3demo_superlock(zPath, zVfs, xBusy, &busy, &pLock);
  assert( rc==SQLITE_OK || pLock==0 );
  assert( rc!=SQLITE_OK || pLock!=0 );

  if( rc!=SQLITE_OK ){
    extern const char *sqlite3ErrStr(int);
    Tcl_ResetResult(interp);
    Tcl_AppendResult(interp, sqlite3ErrStr(rc), 0);

** mode database files. The interface to the example code in this file 
** consists of the following two functions:
**
**   sqlite3demo_superlock()
**   sqlite3demo_superunlock()
*/

#include "sqlite3.h"
#include <string.h>               /* memset(), strlen() */
#include <assert.h>               /* assert() */

/*
** A structure to collect a busy-handler callback and argument and a count
** of the number of times it has been invoked.
*/
................................................................................
}

/*
** Release a superlock held on a database file. The argument passed to 
** this function must have been obtained from a successful call to
** sqlite3demo_superlock().
*/
static void sqlite3demo_superunlock(void *pLock){
  Superlock *p = (Superlock *)pLock;
  if( p->bWal ){
    int rc;                         /* Return code */
    int flags = SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE;
    sqlite3_file *fd = 0;
    rc = sqlite3_file_control(p->db, "main", SQLITE_FCNTL_FILE_POINTER, (void *)&fd);
    if( rc==SQLITE_OK ){
................................................................................
**
** If a required lock cannot be obtained immediately and the xBusy parameter
** to this function is not NULL, then xBusy is invoked in the same way
** as a busy-handler registered with SQLite (using sqlite3_busy_handler())
** until either the lock can be obtained or the busy-handler function returns
** 0 (indicating "give up").
*/
static int sqlite3demo_superlock(
  const char *zPath,              /* Path to database file to lock */
  const char *zVfs,               /* VFS to use to access database file */
  int flags,                      /* Additional flags to pass to sqlite3_open_v2 */
  int (*xBusy)(void*,int),        /* Busy handler callback */
  void *pBusyArg,                 /* Context arg for busy handler */
  void **ppLock                   /* OUT: Context to pass to superunlock() */
){
  SuperlockBusy busy = {0, 0, 0}; /* Busy handler wrapper object */
  int rc;                         /* Return code */
  Superlock *pLock;
................................................................................

  pLock = sqlite3_malloc(sizeof(Superlock));
  if( !pLock ) return SQLITE_NOMEM;
  memset(pLock, 0, sizeof(Superlock));

  /* Open a database handle on the file to superlock. */
  rc = sqlite3_open_v2(
    zPath, &pLock->db, SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|flags, zVfs
  );

  /* Install a busy-handler and execute a BEGIN EXCLUSIVE. If this is not
  ** a WAL database, this is all we need to do.  
  **
  ** A wrapper function is used to invoke the busy-handler instead of
  ** registering the busy-handler function supplied by the user directly
................................................................................
  }
  if( objc>4 ){
    busy.interp = interp;
    busy.pScript = objv[4];
    xBusy = superlock_busy;
  }

  rc = sqlite3demo_superlock(zPath, zVfs, 0, xBusy, &busy, &pLock);
  assert( rc==SQLITE_OK || pLock==0 );
  assert( rc!=SQLITE_OK || pLock!=0 );

  if( rc!=SQLITE_OK ){
    extern const char *sqlite3ErrStr(int);
    Tcl_ResetResult(interp);
    Tcl_AppendResult(interp, sqlite3ErrStr(rc), 0);

  db = p->db;
  sqlite3StrAccumInit(&out, zBase, sizeof(zBase), 
                      db->aLimit[SQLITE_LIMIT_LENGTH]);
  out.db = db;
  if( db->vdbeExecCnt>1 ){
    while( *zRawSql ){
      const char *zStart = zRawSql;


      while( *(zRawSql++)!='\n' && *zRawSql );
      sqlite3StrAccumAppend(&out, "-- ", 3);

      sqlite3StrAccumAppend(&out, zStart, (int)(zRawSql-zStart));
    }
  }else{
    while( zRawSql[0] ){
      n = findNextHostParameter(zRawSql, &nToken);
      assert( n>0 );
      sqlite3StrAccumAppend(&out, zRawSql, n);
      zRawSql += n;

  db = p->db;
  sqlite3StrAccumInit(&out, zBase, sizeof(zBase), 
                      db->aLimit[SQLITE_LIMIT_LENGTH]);
  out.db = db;
  if( db->vdbeExecCnt>1 ){
    while( *zRawSql ){
      const char *zStart = zRawSql;
      sqlite_int64 iStart = SQLITE_PTR_TO_INT(zRawSql);
      sqlite_int64 iCurrent;
      while( *(zRawSql++)!='\n' && *zRawSql );
      sqlite3StrAccumAppend(&out, "-- ", 3);
      iCurrent = SQLITE_PTR_TO_INT(zRawSql);
      sqlite3StrAccumAppend(&out, zStart, (int)(iCurrent-iStart));
    }
  }else{
    while( zRawSql[0] ){
      n = findNextHostParameter(zRawSql, &nToken);
      assert( n>0 );
      sqlite3StrAccumAppend(&out, zRawSql, n);
      zRawSql += n;

*/
int sqlite3WalOpen(
  sqlite3_vfs *pVfs,              /* vfs module to open wal and wal-index */
  sqlite3_file *pDbFd,            /* The open database file */
  const char *zWalName,           /* Name of the WAL file */
  int bNoShm,                     /* True to run in heap-memory mode */
  i64 mxWalSize,                  /* Truncate WAL to this size on reset */

  Wal **ppWal                     /* OUT: Allocated Wal handle */
){
  int rc;                         /* Return Code */
  Wal *pRet;                      /* Object to allocate and return */
  int flags;                      /* Flags passed to OsOpen() */

  assert( zWalName && zWalName[0] );
  assert( pDbFd );

  /* In the amalgamation, the os_unix.c and os_win.c source files come before
  ** this source file.  Verify that the #defines of the locking byte offsets
  ** in os_unix.c and os_win.c agree with the WALINDEX_LOCK_OFFSET value.
................................................................................
  pRet->pDbFd = pDbFd;
  pRet->readLock = -1;
  pRet->mxWalSize = mxWalSize;
  pRet->zWalName = zWalName;
  pRet->exclusiveMode = (bNoShm ? WAL_HEAPMEMORY_MODE: WAL_NORMAL_MODE);

  /* Open file handle on the write-ahead log file. */
  flags = (SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|SQLITE_OPEN_WAL);
  rc = sqlite3OsOpen(pVfs, zWalName, pRet->pWalFd, flags, &flags);
  if( rc==SQLITE_OK && flags&SQLITE_OPEN_READONLY ){
    pRet->readOnly = WAL_RDONLY;
  }

  if( rc!=SQLITE_OK ){
    walIndexClose(pRet, 0);
    sqlite3OsClose(pRet->pWalFd);
    sqlite3_free(pRet);

*/
int sqlite3WalOpen(
  sqlite3_vfs *pVfs,              /* vfs module to open wal and wal-index */
  sqlite3_file *pDbFd,            /* The open database file */
  const char *zWalName,           /* Name of the WAL file */
  int bNoShm,                     /* True to run in heap-memory mode */
  i64 mxWalSize,                  /* Truncate WAL to this size on reset */
  int flags,                      /* VFS file protection flags */
  Wal **ppWal                     /* OUT: Allocated Wal handle */
){
  int rc;                         /* Return Code */
  Wal *pRet;                      /* Object to allocate and return */
  int vfsFlags;                   /* Flags passed to OsOpen() */

  assert( zWalName && zWalName[0] );
  assert( pDbFd );

  /* In the amalgamation, the os_unix.c and os_win.c source files come before
  ** this source file.  Verify that the #defines of the locking byte offsets
  ** in os_unix.c and os_win.c agree with the WALINDEX_LOCK_OFFSET value.
................................................................................
  pRet->pDbFd = pDbFd;
  pRet->readLock = -1;
  pRet->mxWalSize = mxWalSize;
  pRet->zWalName = zWalName;
  pRet->exclusiveMode = (bNoShm ? WAL_HEAPMEMORY_MODE: WAL_NORMAL_MODE);

  /* Open file handle on the write-ahead log file. */
  vfsFlags = flags | (SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|SQLITE_OPEN_WAL);
  rc = sqlite3OsOpen(pVfs, zWalName, pRet->pWalFd, vfsFlags, &vfsFlags);
  if( rc==SQLITE_OK && vfsFlags&SQLITE_OPEN_READONLY ){
    pRet->readOnly = WAL_RDONLY;
  }

  if( rc!=SQLITE_OK ){
    walIndexClose(pRet, 0);
    sqlite3OsClose(pRet->pWalFd);
    sqlite3_free(pRet);

/* Connection to a write-ahead log (WAL) file. 
** There is one object of this type for each pager. 
*/
typedef struct Wal Wal;

/* Open and close a connection to a write-ahead log. */
int sqlite3WalOpen(sqlite3_vfs*, sqlite3_file*, const char *, int, i64, Wal**);
int sqlite3WalClose(Wal *pWal, int sync_flags, int, u8 *);

/* Set the limiting size of a WAL file. */
void sqlite3WalLimit(Wal*, i64);

/* Used by readers to open (lock) and close (unlock) a snapshot.  A 
** snapshot is like a read-transaction.  It is the state of the database

/* Connection to a write-ahead log (WAL) file. 
** There is one object of this type for each pager. 
*/
typedef struct Wal Wal;

/* Open and close a connection to a write-ahead log. */
int sqlite3WalOpen(sqlite3_vfs*, sqlite3_file*, const char *, int, i64, int, Wal**);
int sqlite3WalClose(Wal *pWal, int sync_flags, int, u8 *);

/* Set the limiting size of a WAL file. */
void sqlite3WalLimit(Wal*, i64);

/* Used by readers to open (lock) and close (unlock) a snapshot.  A 
** snapshot is like a read-transaction.  It is the state of the database

}]
ifcapable !wal { set skipwaltests 1 }
if {![wal_is_ok]} { set skipwaltests 1 }

if {!$skipwaltests} {
  db close
  file delete -force test.db

  sqlite3 db test.db
  file_control_chunksize_test db main [expr 32*1024]
  
  do_test fallocate-2.1 {
    execsql {
      PRAGMA page_size = 1024;
      PRAGMA journal_mode = WAL;

}]
ifcapable !wal { set skipwaltests 1 }
if {![wal_is_ok]} { set skipwaltests 1 }

if {!$skipwaltests} {
  db close
  file delete -force test.db
  if {[forced_proxy_locking]} { file delete -force .test.db-conch }
  sqlite3 db test.db
  file_control_chunksize_test db main [expr 32*1024]
  
  do_test fallocate-2.1 {
    execsql {
      PRAGMA page_size = 1024;
      PRAGMA journal_mode = WAL;

  set dbversion [hexio_get_int [hexio_read test.db 24 4]]
  incr dbversion
  hexio_write test.db 24 [hexio_render_int32 $dbversion]

  return ""
}





do_test incrblob3-7.2 {
  sqlite3 db test.db 
  sqlite3_db_config_lookaside db 0 0 0
  list [catch {db incrblob blobs v 1} msg] $msg
} {1 {database schema has changed}}
db close

tvfs delete

finish_test

  set dbversion [hexio_get_int [hexio_read test.db 24 4]]
  incr dbversion
  hexio_write test.db 24 [hexio_render_int32 $dbversion]

  return ""
}

#set sqlite_os_trace 1
# AFP asserts because the "db incrblob blobs v 1" clears the file locks and the unlock fails (HFS doesn't care about a failed unlock)
if {[path_is_local "."]} {

  do_test incrblob3-7.2 {
    sqlite3 db test.db 
    sqlite3_db_config_lookaside db 0 0 0
    list [catch {db incrblob blobs v 1} msg] $msg
  } {1 {database schema has changed}}
  db close
}
tvfs delete

finish_test

#
#***********************************************************************
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/malloc_common.tcl







set g_chunk_size [ expr ($::SQLITE_MAX_PAGE_SIZE*16384) ]
set g_max_chunks 32

# This handles appending the chunk number
# to the end of the filename.  if 
# SQLITE_MULTIPLEX_EXT_OVWR is defined, then

#
#***********************************************************************
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/malloc_common.tcl

# AFP doesn't like multiplex db tests
if { ![path_is_local "."] } {
  finish_test 
  return 
}

set g_chunk_size [ expr ($::SQLITE_MAX_PAGE_SIZE*16384) ]
set g_max_chunks 32

# This handles appending the chunk number
# to the end of the filename.  if 
# SQLITE_MULTIPLEX_EXT_OVWR is defined, then

    set ::mj_filename_length [string length $filename]
    faultsim_save 
  }
  return SQLITE_OK
}

set pwd [pwd]


foreach {tn1 tcl} {
  1 { set prefix "test.db" }
  2 { 
    # This test depends on the underlying VFS being able to open paths
    # 512 bytes in length. The idea is to create a hot-journal file that
    # contains a master-journal pointer so large that it could contain
    # a valid page record (if the file page-size is 512 bytes). So as to
................................................................................
  }

  cd $pwd
}
db close
tv delete
file delete -force $dirname



# Set up a VFS to make a copy of the file-system just before deleting a
# journal file to commit a transaction. The transaction modifies exactly
# two database pages (and page 1 - the change counter).
#
testvfs tv -default 1
................................................................................
  testvfs tv -default 1
  tv filter xSync
  tv script xSyncCb
  proc xSyncCb {args} {incr ::synccount}
  set ::synccount 0
  sqlite3 db test.db
  execsql {
    PRAGMA synchronous = off;
    PRAGMA journal_mode = WAL;

    INSERT INTO ko DEFAULT VALUES;
  }
  execsql { PRAGMA wal_checkpoint }
  set synccount
} {0}
db close
tv delete

    set ::mj_filename_length [string length $filename]
    faultsim_save 
  }
  return SQLITE_OK
}

set pwd [pwd]
if {![forced_proxy_locking]} {
  # proxy locking uses can't deal with auto proxy file paths longer than MAXPATHLEN
foreach {tn1 tcl} {
  1 { set prefix "test.db" }
  2 { 
    # This test depends on the underlying VFS being able to open paths
    # 512 bytes in length. The idea is to create a hot-journal file that
    # contains a master-journal pointer so large that it could contain
    # a valid page record (if the file page-size is 512 bytes). So as to
................................................................................
  }

  cd $pwd
}
db close
tv delete
file delete -force $dirname
}


# Set up a VFS to make a copy of the file-system just before deleting a
# journal file to commit a transaction. The transaction modifies exactly
# two database pages (and page 1 - the change counter).
#
testvfs tv -default 1
................................................................................
  testvfs tv -default 1
  tv filter xSync
  tv script xSyncCb
  proc xSyncCb {args} {incr ::synccount}
  set ::synccount 0
  sqlite3 db test.db
  execsql {

    PRAGMA journal_mode = WAL;
    PRAGMA synchronous = off;
    INSERT INTO ko DEFAULT VALUES;
  }
  execsql { PRAGMA wal_checkpoint }
  set synccount
} {0}
db close
tv delete

    sqlite3 db2 test.db
    execsql "PRAGMA lock_proxy_file='$lpp2'" db2
    catchsql {
      select * from sqlite_master;
    } db2
  } {1 {database is locked}}

  set lpp3 [exec mktemp -t 'proxy3']

  # lock proxy file can be renamed if no other connections are active
  do_test pragma-16.4 {
    db2 close
    db close
    sqlite3 db2 test.db
    execsql "PRAGMA lock_proxy_file='$lpp3'" db2
................................................................................
    list [catch {
      sqlite3 db test2.db
      execsql { select * from sqlite_master } 
    } msg] $msg
  } {1 {database is locked}}

  db2 close
  set lpp4 [exec mktemp -t 'proxy4']

  # check that db is unlocked after first host connection closes 
  do_test pragma-16.8.1 {
    execsql "PRAGMA lock_proxy_file='$lpp4'" 
    execsql "select * from sqlite_master"
    execsql "PRAGMA lock_proxy_file"
  } $lpp4
................................................................................
      PRAGMA lock_proxy_file=":auto:";
      PRAGMA lock_proxy_file;
    } db]
    string match "*proxytest.db:auto:" $lockpath2
  } {1}

  # ensure creating directories for a lock proxy file works
  set lpp5 [exec mktemp -d -t "proxy5"]/sub/dir/lock
  db close
  file delete -force proxytest
  do_test pragma-16.10.1 {
    sqlite3 db proxytest.db
    execsql "PRAGMA lock_proxy_file='$lpp5'" 
    set lockpath2 [execsql {
      PRAGMA lock_proxy_file;
    } db]
    string match "*sub/dir/lock" $lockpath2
  } {1}

  # ensure that after deleting the path, setting ":auto:" works correctly
  db close
  file delete -force proxytest
  do_test pragma-16.10.2 {
    sqlite3 db proxytest.db
    set lockpath3 [execsql {
      PRAGMA lock_proxy_file=":auto:";
      create table if not exists pt(y);
      PRAGMA lock_proxy_file;
    } db]
    string match "*sub/dir/lock" $lockpath3
  } {1}

  # ensure that if the path can not be created (file instead of dir)
  # setting :auto: deals with it by creating a new autonamed lock file
  db close
  file delete -force proxytest
  close [open "proxytest" a]
  do_test pragma-16.10.3 {
    sqlite3 db proxytest.db
    set lockpath2 [execsql {
      PRAGMA lock_proxy_file=":auto:";
      create table if not exists zz(y);
      PRAGMA lock_proxy_file;
    } db]
    string match "*proxytest.db:auto:" $lockpath2
  } {1}

  # make sure we can deal with ugly file paths correctly
  set lpp6 [exec mktemp -d -t "proxy6"]/./././////./proxytest/../proxytest/sub/dir/lock
  db close
  file delete -force proxytest

  do_test pragma-16.10.4 {
    sqlite3 db proxytest.db
    execsql "PRAGMA lock_proxy_file='$lpp6'" 
    set lockpath4 [execsql {
      create table if not exists aa(bb);
      PRAGMA lock_proxy_file;
    } db]
    string match "*proxytest/sub/dir/lock" $lockpath4
  } {1}

  # ensure that if the path can not be created (perm), setting :auto: deals
  db close
  file delete -force proxytest
  do_test pragma-16.10.5 {
    sqlite3 db proxytest.db
    execsql "PRAGMA lock_proxy_file='$lpp5'" 
    execsql {
      create table if not exists bb(bb);
    }
    db close
    file delete -force proxytest
    file mkdir proxytest
    file attributes proxytest -permission 0000
    sqlite3 db proxytest.db
    set lockpath5 [execsql {
      PRAGMA lock_proxy_file=":auto:";
      create table if not exists cc(bb);
      PRAGMA lock_proxy_file;
    } db]
    string match "*proxytest.db:auto:" $lockpath5
................................................................................
    catchsql {
      create table if not exists faily(y);
      PRAGMA lock_proxy_file;
    } db
  } {1 {database is locked}}
  db close

  file attributes proxytest -permission 0777
  file delete -force proxytest

  set env(SQLITE_FORCE_PROXY_LOCKING) $using_proxy
  set sqlite_hostid_num 0
}

# Parsing of auto_vacuum settings.
#

    sqlite3 db2 test.db
    execsql "PRAGMA lock_proxy_file='$lpp2'" db2
    catchsql {
      select * from sqlite_master;
    } db2
  } {1 {database is locked}}

  set lpp3 [exec mktemp -t "proxy3"]

  # lock proxy file can be renamed if no other connections are active
  do_test pragma-16.4 {
    db2 close
    db close
    sqlite3 db2 test.db
    execsql "PRAGMA lock_proxy_file='$lpp3'" db2
................................................................................
    list [catch {
      sqlite3 db test2.db
      execsql { select * from sqlite_master } 
    } msg] $msg
  } {1 {database is locked}}

  db2 close
  set lpp4 [exec mktemp -t "proxy4"]

  # check that db is unlocked after first host connection closes 
  do_test pragma-16.8.1 {
    execsql "PRAGMA lock_proxy_file='$lpp4'" 
    execsql "select * from sqlite_master"
    execsql "PRAGMA lock_proxy_file"
  } $lpp4
................................................................................
      PRAGMA lock_proxy_file=":auto:";
      PRAGMA lock_proxy_file;
    } db]
    string match "*proxytest.db:auto:" $lockpath2
  } {1}

  # ensure creating directories for a lock proxy file works
  set lpp5d [exec mktemp -d -t "proxy5"]
  set lpp5 $lpp5d/sub/dir/lock
  db close
  do_test pragma-16.10.1 {
    sqlite3 db proxytest.db
    execsql "PRAGMA lock_proxy_file='$lpp5'" 
    set lockpath2 [execsql {
      PRAGMA lock_proxy_file;
    } db]
    string match "*sub/dir/lock" $lockpath2
  } {1}

  # ensure that after deleting the path, setting ":auto:" works correctly
  db close
  file delete -force $lpp5d
  do_test pragma-16.10.2 {
    sqlite3 db proxytest.db
    set lockpath3 [execsql {
      PRAGMA lock_proxy_file=":auto:";
      create table if not exists pt(y);
      PRAGMA lock_proxy_file;
    } db]
    string match "*sub/dir/lock" $lockpath3
  } {1}

  # ensure that if the path can not be created (file instead of dir)
  # setting :auto: deals with it by creating a new autonamed lock file
  db close
  file delete -force $lpp5d
  close [open "$lpp5d" a]
  do_test pragma-16.10.3 {
    sqlite3 db proxytest.db
    set lockpath2 [execsql {
      PRAGMA lock_proxy_file=":auto:";
      create table if not exists zz(y);
      PRAGMA lock_proxy_file;
    } db]
    string match "*proxytest.db:auto:" $lockpath2
  } {1}

  # make sure we can deal with ugly file paths correctly

  db close
  file delete -force $lpp5d
  set lpp6 [exec mktemp -d -t "proxy6"]/./././////./proxytest/../proxytest/sub/dir/lock
  do_test pragma-16.10.4 {
    sqlite3 db proxytest.db
    execsql "PRAGMA lock_proxy_file='$lpp6'" 
    set lockpath4 [execsql {
      create table if not exists aa(bb);
      PRAGMA lock_proxy_file;
    } db]
    string match "*proxytest/sub/dir/lock" $lockpath4
  } {1}

  # ensure that if the path can not be created (perm), setting :auto: deals
  db close
  file delete -force $lpp5d
  do_test pragma-16.10.5 {
    sqlite3 db proxytest.db
    execsql "PRAGMA lock_proxy_file='$lpp5'" 
    execsql {
      create table if not exists bb(bb);
    }
    db close
    file delete -force $lpp5d
    file mkdir $lpp5d
    file attributes $lpp5d -permission 0000
    sqlite3 db proxytest.db
    set lockpath5 [execsql {
      PRAGMA lock_proxy_file=":auto:";
      create table if not exists cc(bb);
      PRAGMA lock_proxy_file;
    } db]
    string match "*proxytest.db:auto:" $lockpath5
................................................................................
    catchsql {
      create table if not exists faily(y);
      PRAGMA lock_proxy_file;
    } db
  } {1 {database is locked}}
  db close

  file attributes $lpp5d -permission 0777
  file delete -force $lpp5d

  set env(SQLITE_FORCE_PROXY_LOCKING) $using_proxy
  set sqlite_hostid_num 0
}

# Parsing of auto_vacuum settings.
#

  INSERT INTO t1 VALUES(1, 2);
  PRAGMA journal_mode = DELETE;
} {delete}

do_test 1.2 { sqlite3demo_superlock unlock test.db } {unlock}
do_catchsql_test 1.3 { SELECT * FROM t1 } {1 {database is locked}}
do_test 1.4 { unlock } {}







do_execsql_test 2.1 { 
  INSERT INTO t1 VALUES(3, 4);
  PRAGMA journal_mode = WAL;
} {wal}

do_test 2.2 { sqlite3demo_superlock unlock test.db } {unlock}

  INSERT INTO t1 VALUES(1, 2);
  PRAGMA journal_mode = DELETE;
} {delete}

do_test 1.2 { sqlite3demo_superlock unlock test.db } {unlock}
do_catchsql_test 1.3 { SELECT * FROM t1 } {1 {database is locked}}
do_test 1.4 { unlock } {}

ifcapable !wal {finish_test ; return }
if { ![wal_is_ok] } {
  finish_test 
  return 
}

do_execsql_test 2.1 { 
  INSERT INTO t1 VALUES(3, 4);
  PRAGMA journal_mode = WAL;
} {wal}

do_test 2.2 { sqlite3demo_superlock unlock test.db } {unlock}

}

# Update the soft-heap-limit each time this script is run. In that
# way if an individual test file changes the soft-heap-limit, it
# will be reset at the start of the next test file.
#
sqlite3_soft_heap_limit $cmdlinearg(soft-heap-limit)


















# Create a test database
#
proc reset_db {} {
  catch {db close}
  file delete -force test.db
  file delete -force test.db-journal
  file delete -force test.db-wal








  sqlite3 db ./test.db
  set ::DB [sqlite3_connection_pointer db]
  if {[info exists ::SETUP_SQL]} {
    db eval $::SETUP_SQL
  }
}
reset_db
................................................................................
}
proc presql {} {
  set presql ""
  catch {set presql $::G(perm:presql)}
  set presql
}

proc forced_proxy_locking {} {
  ifcapable lock_proxy_pragmas&&prefer_proxy_locking {
    set force_proxy_value 0
    set force_key "SQLITE_FORCE_PROXY_LOCKING="
    foreach {env_pair} [exec env] { 
      if { [string first $force_key $env_pair] == 0} {
        set force_proxy_value [string range $env_pair [string length $force_key] end]
      }
    }
    if { "$force_proxy_value " == "1 " } {
      return 1
    } 
  }
  return 0
}

proc wal_is_ok {} {
  if { [forced_proxy_locking] } {
    return 1
  }
  if { ![path_is_local "."] } {
    return 0
  }

}

# Update the soft-heap-limit each time this script is run. In that
# way if an individual test file changes the soft-heap-limit, it
# will be reset at the start of the next test file.
#
sqlite3_soft_heap_limit $cmdlinearg(soft-heap-limit)

proc forced_proxy_locking {} {
  if $::sqlite_options(lock_proxy_pragmas)&&$::sqlite_options(prefer_proxy_locking) {
    set force_proxy_value 0
    set force_key "SQLITE_FORCE_PROXY_LOCKING="
    foreach {env_pair} [exec env] { 
      if { [string first $force_key $env_pair] == 0} {
        set force_proxy_value [string range $env_pair [string length $force_key] end]
      }
    }
    if { "$force_proxy_value " == "1 " } {
      return 1
    } 
  }
  return 0
}


# Create a test database
#
proc reset_db {} {
  catch {db close}
  file delete -force test.db
  file delete -force test.db-journal
  file delete -force test.db-wal
  if {[forced_proxy_locking]} {
    sqlite3 db ./test.db
    set lock_proxy_path [db eval "PRAGMA lock_proxy_file;"] 
    catch {db close}
    # puts "deleting $lock_proxy_path"
    file delete -force $lock_proxy_path    
    file delete -force test.db
  }
  sqlite3 db ./test.db
  set ::DB [sqlite3_connection_pointer db]
  if {[info exists ::SETUP_SQL]} {
    db eval $::SETUP_SQL
  }
}
reset_db
................................................................................
}
proc presql {} {
  set presql ""
  catch {set presql $::G(perm:presql)}
  set presql
}

















proc wal_is_ok {} {
  if { [forced_proxy_locking] } {
    return 1
  }
  if { ![path_is_local "."] } {
    return 0
  }

# Test that "PRAGMA checkpoint_fullsync" appears to be working.
#
foreach {tn sql reslist} {
  1 { }                                 {8 0 3 0 5 0}
  2 { PRAGMA checkpoint_fullfsync = 1 } {8 4 3 2 5 2}
  3 { PRAGMA checkpoint_fullfsync = 0 } {8 0 3 0 5 0}
} {





  faultsim_delete_and_reopen

  execsql {PRAGMA auto_vacuum = 0}
  execsql $sql
  do_execsql_test wal2-14.$tn.1 { PRAGMA journal_mode = WAL } {wal}

  set sqlite_sync_count 0

# Test that "PRAGMA checkpoint_fullsync" appears to be working.
#
foreach {tn sql reslist} {
  1 { }                                 {8 0 3 0 5 0}
  2 { PRAGMA checkpoint_fullfsync = 1 } {8 4 3 2 5 2}
  3 { PRAGMA checkpoint_fullfsync = 0 } {8 0 3 0 5 0}
} {
  if { $::sqlite_options(default_ckptfullfsync) && $tn == 1} {
    # checkpoint_fullfsync on by default
    set reslist {8 4 3 2 5 2}
  }

  faultsim_delete_and_reopen

  execsql {PRAGMA auto_vacuum = 0}
  execsql $sql
  do_execsql_test wal2-14.$tn.1 { PRAGMA journal_mode = WAL } {wal}

  set sqlite_sync_count 0

  1 off     
    {}
  2 normal  
    {test.db-wal normal test.db normal}
  3 full    
    {test.db-wal normal test.db-wal normal test.db-wal normal test.db normal}
} {











  proc sync_counter {args} { 
    foreach {method filename id flags} $args break
    lappend ::syncs [file tail $filename] $flags
  }
  do_test wal3-3.$tn {
    file delete -force test.db test.db-wal test.db-journal

  1 off     
    {}
  2 normal  
    {test.db-wal normal test.db normal}
  3 full    
    {test.db-wal normal test.db-wal normal test.db-wal normal test.db normal}
} {

  if { $::sqlite_options(default_ckptfullfsync) } {
    # checkpoint_fullfsync on by default
    if { $tn == 2} {
      set synccount {test.db-wal full test.db full}
    }
    if { $tn == 3} {
      set synccount {test.db-wal normal test.db-wal normal test.db-wal full test.db full}
    }
  }

  proc sync_counter {args} { 
    foreach {method filename id flags} $args break
    lappend ::syncs [file tail $filename] $flags
  }
  do_test wal3-3.$tn {
    file delete -force test.db test.db-wal test.db-journal

set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/lock_common.tcl
source $testdir/wal_common.tcl
source $testdir/malloc_common.tcl
ifcapable !wal {finish_test ; return }



#-------------------------------------------------------------------------
# Changing to WAL mode in one connection forces the change in others.
#
db close
forcedelete test.db

set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/lock_common.tcl
source $testdir/wal_common.tcl
source $testdir/malloc_common.tcl
ifcapable !wal {finish_test ; return }

if { ![wal_is_ok] } {finish_test ; return }

#-------------------------------------------------------------------------
# Changing to WAL mode in one connection forces the change in others.
#
db close
forcedelete test.db

set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/lock_common.tcl
source $testdir/wal_common.tcl
ifcapable !wal {finish_test ; return }
if { ![wal_is_ok] } {
  finish_test 
  return 
}


#-------------------------------------------------------------------------
# This test case demonstrates a flaw in the wal-index manipulation that
# existed at one point: If a process crashes mid-transaction, it may have
# already added some entries to one of the hash-tables in the wal-index.
# If the transaction were to be explicitly rolled back at this point, the

set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/lock_common.tcl
source $testdir/wal_common.tcl
ifcapable !wal {finish_test ; return }
if { ![wal_is_ok] } { finish_test ; return }





#-------------------------------------------------------------------------
# This test case demonstrates a flaw in the wal-index manipulation that
# existed at one point: If a process crashes mid-transaction, it may have
# already added some entries to one of the hash-tables in the wal-index.
# If the transaction were to be explicitly rolled back at this point, the

# These tests are only going to work on unix.
#
if {$::tcl_platform(platform) != "unix"} {
  finish_test
  return
}








do_multiclient_test tn {
  # Do not run tests with the connections in the same process.
  #
  if {$tn==2} continue
  
  # Close all connections and delete the database.

# These tests are only going to work on unix.
#
if {$::tcl_platform(platform) != "unix"} {
  finish_test
  return
}

# these tests can't deal with the location of the -shm file under proxy locking
#
if {[forced_proxy_locking]} {
  finish_test
  return
}

do_multiclient_test tn {
  # Do not run tests with the connections in the same process.
  #
  if {$tn==2} continue
  
  # Close all connections and delete the database.