~drizzle-trunk/drizzle/development

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2008 Sun Microsystems

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; version 2 of the License.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, write to the Free Software

 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 */

#ifndef ERROR_INJECT_SUPPORT

/**  

 * @file 

 *

 * Simple compile-time error injection module to enable easy 

 * error printing in case of a crash

 */

#ifndef DRIZZLE_SERVER_ERROR_INJECTION_H

#define DRIZZLE_SERVER_ERROR_INJECTION_H

/*

  Error injector Macros to enable easy testing of recovery after failures

  in various error cases.

*/

#define ERROR_INJECT(x) 0

#define ERROR_INJECT_ACTION(x,action) 0

#define ERROR_INJECT_CRASH(x) 0

#define ERROR_INJECT_VALUE(x) 0

#define ERROR_INJECT_VALUE_ACTION(x,action) 0

#define ERROR_INJECT_VALUE_CRASH(x) 0

#define SET_ERROR_INJECT_VALUE(x)

#else

inline bool check_and_unset_keyword(const char *dbug_str)

{

  const char *extra_str= "-d,";

  char total_str[200];

  if (_db_strict_keyword_ (dbug_str))

  {

    strxmov(total_str, extra_str, dbug_str, NullS);

    return 1;

  }

  return 0;

}

inline bool

check_and_unset_inject_value(int value)

{

  THD *thd= current_thd;

  if (thd->error_inject_value == (uint)value)

  {

    thd->error_inject_value= 0;

    return 1;

  }

  return 0;

}

/*

  ERROR INJECT MODULE:

  --------------------

  These macros are used to insert macros from the application code.

  The event that activates those error injections can be activated

  from SQL by using:

  SET SESSION dbug=+d,code;

  After the error has been injected, the macros will automatically

  remove the debug code, thus similar to using:

  SET SESSION dbug=-d,code

  from SQL.

  ERROR_INJECT_CRASH will inject a crash of the MySQL Server if code

  is set when macro is called. ERROR_INJECT_CRASH can be used in

  if-statements, it will always return false unless of course it

  crashes in which case it doesn't return at all.

  ERROR_INJECT_ACTION will inject the action specified in the action

  parameter of the macro, before performing the action the code will

  be removed such that no more events occur. ERROR_INJECT_ACTION

  can also be used in if-statements and always returns FALSE.

  ERROR_INJECT can be used in a normal if-statement, where the action

  part is performed in the if-block. The macro returns TRUE if the

  error was activated and otherwise returns FALSE. If activated the

  code is removed.

  Sometimes it is necessary to perform error inject actions as a serie

  of events. In this case one can use one variable on the THD object.

  Thus one sets this value by using e.g. SET_ERROR_INJECT_VALUE(100).

  Then one can later test for it by using ERROR_INJECT_CRASH_VALUE,

  ERROR_INJECT_ACTION_VALUE and ERROR_INJECT_VALUE. This have the same

  behaviour as the above described macros except that they use the

  error inject value instead of a code used by debug macros.

*/

#define SET_ERROR_INJECT_VALUE(x) \

  current_thd->error_inject_value= (x)

#define ERROR_INJECT_ACTION(code, action) \

  (check_and_unset_keyword(code) ? ((action), 0) : 0)

#define ERROR_INJECT(code) \

  check_and_unset_keyword(code)

#define ERROR_INJECT_VALUE(value) \

  check_and_unset_inject_value(value)

#define ERROR_INJECT_VALUE_ACTION(value,action) \

  (check_and_unset_inject_value(value) ? (action) : 0)

#define ERROR_INJECT_VALUE_CRASH(value) \

  ERROR_INJECT_VALUE_ACTION(value, (abort(), 0))

#endif /* DRIZZLE_SERVER_ERROR_INJECTION_H */

#endif /* ERROR_INJECT_SUPPORT */