git.zerfleddert.de Git - fnordlicht-mini/blob - firmware/common/pt/lc-switch.h

1 /*

4 *

5 * Redistribution and use in source and binary forms, with or without

6 * modification, are permitted provided that the following conditions

7 * are met:

8 * 1. Redistributions of source code must retain the above copyright

9 * notice, this list of conditions and the following disclaimer.

10 * 2. Redistributions in binary form must reproduce the above copyright

11 * notice, this list of conditions and the following disclaimer in the

12 * documentation and/or other materials provided with the distribution.

13 * 3. Neither the name of the Institute nor the names of its contributors

14 * may be used to endorse or promote products derived from this software

15 * without specific prior written permission.

16 *

17 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND

18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

20 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE

21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

27 * SUCH DAMAGE.

28 *

29 * This file is part of the Contiki operating system.

30 *

31 * Author: Adam Dunkels <adam@sics.se>

32 *

33 * $Id: lc-switch.h,v 1.4 2006/06/03 11:29:43 adam Exp $

34 */

36 /**

37 * \addtogroup lc

38 * @{

39 */

41 /**

42 * \file

43 * Implementation of local continuations based on switch() statment

44 * \author Adam Dunkels <adam@sics.se>

45 *

46 * This implementation of local continuations uses the C switch()

47 * statement to resume execution of a function somewhere inside the

48 * function's body. The implementation is based on the fact that

49 * switch() statements are able to jump directly into the bodies of

50 * control structures such as if() or while() statmenets.

51 *

52 * This implementation borrows heavily from Simon Tatham's coroutines

53 * implementation in C:

54 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html

55 */

57 #ifndef __LC_SWITCH_H__

58 #define __LC_SWITCH_H__

60 /* WARNING! lc implementation using switch() does not work if an

61 LC_SET() is done within another switch() statement! */

63 /** \hideinitializer */

64 typedef unsigned short lc_t;

66 #define LC_INIT(s) s = 0;

68 #define LC_RESUME(s) switch(s) { case 0:

70 #define LC_SET(s) s = __LINE__; case __LINE__:

72 #define LC_END(s) }

74 #endif /* __LC_SWITCH_H__ */

76 /** @} */