SQLite

*/
#ifndef SQLITE_WIN32_IOERR_RETRY
# define SQLITE_WIN32_IOERR_RETRY 10
#endif
#ifndef SQLITE_WIN32_IOERR_RETRY_DELAY
# define SQLITE_WIN32_IOERR_RETRY_DELAY 25
#endif
static int win32IoerrRetry = SQLITE_WIN32_IOERR_RETRY;
static int win32IoerrRetryDelay = SQLITE_WIN32_IOERR_RETRY_DELAY;

/*
** If a ReadFile() or WriteFile() error occurs, invoke this routine
** to see if it should be retried.  Return TRUE to retry.  Return FALSE
** to give up with an error.
*/
static int retryIoerr(int *pnRetry){
  DWORD e;
  if( *pnRetry>=win32IoerrRetry ){
    return 0;
  }
  e = GetLastError();
  if( e==ERROR_ACCESS_DENIED ||
      e==ERROR_LOCK_VIOLATION ||
      e==ERROR_SHARING_VIOLATION ){
    Sleep(win32IoerrRetryDelay*(1+*pnRetry));
    ++*pnRetry;
    return 1;
  }
  return 0;
}

/*
** Log a I/O error retry episode.
*/
static void logIoerr(int nRetry){
  if( nRetry ){
    sqlite3_log(SQLITE_IOERR, 
      "delayed %dms for lock/sharing conflict",
      win32IoerrRetryDelay*nRetry*(nRetry+1)/2
    );
  }
}

#if SQLITE_OS_WINCE
/*************************************************************************
** This section contains code for WinCE only.

      SimulateIOErrorBenign(1);
      winTruncate(id, sz);
      SimulateIOErrorBenign(0);
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_SYNC_OMITTED: {
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_WIN32_AV_RETRY: {
      int *a = (int*)pArg;
      if( a[0]>0 ){
        win32IoerrRetry = a[0];
      }else{
        a[0] = win32IoerrRetry;
      }
      if( a[1]>0 ){
        win32IoerrRetryDelay = a[1];
      }else{
        a[1] = win32IoerrRetryDelay;
      }
      return SQLITE_OK;
    }
  }
  return SQLITE_NOTFOUND;
}

/*
** Return the sector size in bytes of the underlying block device for

** when the database connection has [PRAGMA synchronous] set to OFF.)^
** Some specialized VFSes need this signal in order to operate correctly
** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 
** VFSes do not need this signal and should silently ignore this opcode.
** Applications should not call [sqlite3_file_control()] with this
** opcode as doing so may disrupt the operation of the specialized VFSes
** that do require it.  
**
** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
** retry counts and intervals for certain disk I/O operations for the
** windows [VFS] in order to work to provide robustness against
** anti-virus programs.  By default, the windows VFS will retry file read,
** file write, and file delete opertions up to 10 times, with a delay
** of 25 milliseconds before the first retry and with the delay increasing
** by an additional 25 milliseconds with each subsequent retry.  This
** opcode allows those to values (10 retries and 25 milliseconds of delay)
** to be adjusted.  The values are changed for all database connections
** within the same process.  The argument is a pointer to an array of two
** integers where the first integer i the new retry count and the second
** integer is the delay.  If either integer is negative, then the setting
** is not changed but instead the prior value of that setting is written
** into the array entry, allowing the current retry settings to be
** interrogated.  The zDbName parameter is ignored.
** 
*/
#define SQLITE_FCNTL_LOCKSTATE        1
#define SQLITE_GET_LOCKPROXYFILE      2
#define SQLITE_SET_LOCKPROXYFILE      3
#define SQLITE_LAST_ERRNO             4
#define SQLITE_FCNTL_SIZE_HINT        5
#define SQLITE_FCNTL_CHUNK_SIZE       6
#define SQLITE_FCNTL_FILE_POINTER     7
#define SQLITE_FCNTL_SYNC_OMITTED     8
#define SQLITE_FCNTL_WIN32_AV_RETRY   9

/*
** CAPI3REF: Mutex Handle
**
** The mutex module within SQLite defines [sqlite3_mutex] to be an
** abstract type for a mutex object.  The SQLite core never looks
** at the internal representation of an [sqlite3_mutex].  It only

      return TCL_ERROR;
    }
  }
#endif
  return TCL_OK;  
}

/*
** tclcmd:   file_control_win32_av_retry DB  NRETRY  DELAY
**
** This TCL command runs the sqlite3_file_control interface with
** the SQLITE_FCNTL_WIN32_AV_RETRY opcode.
*/
static int file_control_win32_av_retry(
  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;
  int a[2];
  char z[100];

  if( objc!=4 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"",
        Tcl_GetStringFromObj(objv[0], 0), " DB NRETRY DELAY", 0);
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ){
    return TCL_ERROR;
  }
  if( Tcl_GetIntFromObj(interp, objv[2], &a[0]) ) return TCL_ERROR;
  if( Tcl_GetIntFromObj(interp, objv[3], &a[1]) ) return TCL_ERROR;
  rc = sqlite3_file_control(db, NULL, SQLITE_FCNTL_WIN32_AV_RETRY, (void*)a);
  sqlite3_snprintf(sizeof(z), z, "%d %d %d", rc, a[0], a[1]);
  Tcl_AppendResult(interp, z, (char*)0);
  return TCL_OK;  
}


/*
** tclcmd:   sqlite3_vfs_list
**
**   Return a tcl list containing the names of all registered vfs's.
*/
static int vfs_list(

  if( objc==1 ){
    char zBuf[200];
    sqlite3_snprintf(sizeof(zBuf), zBuf, "%d %d %d %d %d",
                     x.ok, x.err, x.delay1, x.delay2, x.h);
    Tcl_AppendResult(interp, zBuf, (char*)0);
    return TCL_OK;
  }
  while( x.h && retry<30 ){
    retry++;
    Sleep(100);
  }
  if( x.h ){
    Tcl_AppendResult(interp, "busy", (char*)0);
    return TCL_ERROR;
  }

    return TCL_ERROR;
  }
  _beginthread(win32_file_locker, 0, (void*)&x);
  Sleep(0);
  return TCL_OK;
}
#endif


/*
**      optimization_control DB OPT BOOLEAN
**
** Enable or disable query optimizations using the sqlite3_test_control()
** interface.  Disable if BOOLEAN is false and enable if BOOLEAN is true.
** OPT is the name of the optimization to be disabled.

     { "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   },
     { "file_control_win32_av_retry", file_control_win32_av_retry,  0   },
     { "sqlite3_vfs_list",           vfs_list,     0   },
     { "sqlite3_create_function_v2", test_create_function_v2, 0 },

     /* Functions from os.h */
#ifndef SQLITE_OMIT_UTF16
     { "add_test_collate",        test_collate, 0            },
     { "add_test_collate_needed", test_collate_needed, 0     },

        set x
      } {{delayed #ms for lock/sharing conflict}}
    }
    incr delay1 50
  }
  set ::log {}
}

do_test win32lock-2.0 {
  file_control_win32_av_retry db -1 -1
} {0 10 25}
do_test win32lock-2.1 {
  file_control_win32_av_retry db 1 1
} {0 1 1}

set delay1 50
while {1} {
  sqlite3_sleep 10
  lock_win32_file test.db 0 $::delay1
  set rc [catch {db eval {SELECT x, length(y) FROM t1 ORDER BY rowid}} msg]
  if {$rc} {
    do_test win32lock-2.2-$delay1-fin {
       set ::msg
    } {disk I/O error}
    break
  } else {
    do_test win32lock-2.2-$delay1 {
       set ::msg
    } {1 100000 2 50000 3 25000 4 12500}
    if {$::log!=""} {
      do_test win32lock-2.2-$delay1-log1 {
        regsub {\d+} $::log # x
        set x
      } {{delayed #ms for lock/sharing conflict}}
    }
    incr delay1 50
  }
  set ::log {}
}

file_control_win32_av_retry db 10 25
sqlite3_test_control_pending_byte $old_pending_byte
sqlite3_shutdown
test_sqlite3_log 
sqlite3_initialize
finish_test