includes/hlx/task.h

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/*
** Copyright 2009-2011, helixis.org
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without modification, are permitted provided
** that the following conditions are met:
**
** Redistributions of source code must retain the above copyright notice, this list of conditions and the
** following disclaimer.
**
** Redistributions in binary form must reproduce the above copyright notice, this list of conditions and
** the following disclaimer in the documentation and/or other materials provided with the distribution.
**
** Neither the name of the helixis.org nor the names of its contributors may be used to endorse or promote
** products derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
** PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
** ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
** TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
** NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
** POSSIBILITY OF SUCH DAMAGE.
*/

/*
**    #############################################################################
**    # This implementation is based on the protothreads library by Adam Dunkels. #
**    # For more information : http://www.sics.se/~adam/pt/                       #
**    #                                                                           #
**    # Thanks Adam to share your work with the community. We love you so much :) #
**    #############################################################################
*/

/*
 * Copyright (c) 2004-2005, Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * Author: Adam Dunkels <adam@sics.se>
 */

#ifndef __HLX_TASK_H__
# define __HLX_TASK_H__

#ifdef __cplusplus
extern "C"      {
#endif

/*
** TYPES
*/

typedef unsigned short hlx_ctx; /* 16 bits task context */

typedef int  (*hlx_task_func)(hlx_ctx*, hlx_group_id, void**, void *);

typedef void (*hlx_task_callback)(void *, hlx_group_id, int);

/* TASK STACK TRICKS */
struct __empty_stack
{
        unsigned short __size;
};

/*
** MACROS
*/

/* TASK STATE */
# define HLX_WAITING                    (0)
# define HLX_YIELDED                    (1)
# define HLX_EXITED                             (2)
# define HLX_ENDED                              (3)
# define HLX_MEMORY_EXHAUSTED   (4) /* Only occurs if the someone use the emulated stack */

/*
** Lc switch implementation by Adam Dunkels with Helixis Microsoft compiler bug patch :
** http://support.microsoft.com/default.aspx?scid=kb;en-us;199057
*/
#if defined(COMPILER_MSC)
# define HLX_SET(s) s = __COUNTER__ + 1; case __COUNTER__:
#else
# define HLX_SET(s) s = __LINE__; case __LINE__:
#endif

/* TASK INIT */
# define HLX_TASK_INIT()                                        *ctx = 0;

/* TASK SCOPE */
#define HLX_TASK_BEGIN() { char HLX_YIELD_FLAG = 1; switch(*ctx) { case 0:
#define HLX_TASK_END() } HLX_YIELD_FLAG = 0; HLX_TASK_INIT(); return HLX_ENDED; }

/* TASK EXIT */
#define HLX_TASK_EXIT()                         \
  do {                                          \
    HLX_TASK_INIT();                            \
    return HLX_EXITED;                  \
  } while(0)

/* TASK RESTART */
#define HLX_TASK_RESTART()                                      \
  do {                                          \
    HLX_TASK_INIT();                            \
    return HLX_WAITING;                 \
  } while(0)

/* TASK WAIT UNTIL */
#define HLX_TASK_WAIT_UNTIL(condition)          \
  do {                                          \
    HLX_SET(*ctx);                              \
    if(!(condition)) {                          \
      return HLX_WAITING;                       \
    }                                           \
  } while(0)

/* HLX TASK YIELD */
#define HLX_TASK_YIELD()                                \
  do {                                          \
    HLX_YIELD_FLAG = 0;                         \
    HLX_SET(*ctx);                              \
    if(HLX_YIELD_FLAG == 0) {                   \
      return HLX_YIELDED;                       \
    }                                           \
  } while(0)

/* TASK YIELD UNTIL */
#define HLX_TASK_YIELD_UNTIL(cond)              \
  do {                                          \
    HLX_YIELD_FLAG = 0;                         \
    HLX_SET(*ctx);                              \
    if((HLX_YIELD_FLAG == 0) || !(cond)) {      \
      return HLX_YIELDED;                       \
    }                                           \
  } while(0)

/* TASK WAIT WHILE */
#define HLX_TASK_WAIT_WHILE(cond) HLX_TASK_WAIT_UNTIL(!(cond))

/* TASK STACK */
# define HLX_STACK(VARS)        struct __local { VARS unsigned short __size; };\
                                                if (*__stack == 0 && sizeof(struct __local) > sizeof(struct __empty_stack)) \
                                                { \
                                                        *__stack = hlx_api_entries()->malloc_entry(sizeof(struct __local)); \
                                                        if (!*__stack) return (-1); \
                                                        HLX_L(__size) = sizeof(struct __local); \
                                                }
# define HLX_L(VAR)             (((struct __local* )*__stack)->VAR)

/* TASK PROTOTYPES */
# define HLX_TASK(TASKNAME, PARAMETER)  int TASKNAME(hlx_ctx* ctx, hlx_group_id self_group_id, void* *__stack, PARAMETER)
# define HLX_SIMPLE_TASK(TASKNAME)              HLX_TASK(TASKNAME, void* __unused_var__)

/* ADD TASK */
# define HLX_TASK_ADD(TASK, DATA)                                                                       hlx_core_add_task_callback(TASK, DATA, self_group_id, 0)
# define HLX_TASK_ADD_IN_GROUP(TASK, DATA, GROUP)                                       hlx_core_add_task_in_group_callback(TASK, DATA, GROUP, self_group_id, 0)
# define HLX_TASK_ADD_CALLBACK(TASK, DATA, CALLBACK)                                    hlx_core_add_task_callback(TASK, DATA, self_group_id, CALLBACK)
# define HLX_TASK_ADD_IN_GROUP_CALLBACK(TASK, DATA, GROUP, CALLBACK)    hlx_core_add_task_in_group_callback(TASK, DATA, GROUP, self_group_id, CALLBACK)

#ifdef __cplusplus
}
#endif

#endif /* !__HLX_TASK_H__ */

/*
** END OF FILE
*/