LUFA/Scheduler/Scheduler.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2010.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaim all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *
  33  *  Simple round-robbin cooperative scheduler for use in basic projects where non real-time tasks need
  34  *  to be executed. Each task is executed in sequence, and can be enabled or disabled individually or as a group.
  35  *
  36  *  \deprecated This module is deprecated and will be removed in a future library release.
  37  */
  38
  39 /** @defgroup Group_Scheduler Simple Task Scheduler - LUFA/Scheduler/Scheduler.h
  40  *
  41  *  \deprecated This module is deprecated and will be removed in a future library release.
  42  *
  43  *  \section Sec_Dependencies Module Source Dependencies
  44  *  The following files must be built with any user project that uses this module:
  45  *    - LUFA/Scheduler/Scheduler.c
  46  *
  47  *  \section Module Description
  48  *  Simple round-robbin cooperative scheduler for use in basic projects where non real-time tasks need
  49  *  to be executed. Each task is executed in sequence, and can be enabled or disabled individually or as a group.
  50  *
  51  *  For a task to yield it must return, thus each task should have persistent data marked with the static attribute.
  52  *
  53  *  Usage Example:
  54  *  \code
  55  *      #include <LUFA/Scheduler/Scheduler.h>
  56  *
  57  *      TASK(MyTask1);
  58  *      TASK(MyTask2);
  59  *
  60  *      TASK_LIST
  61  *      {
  62  *              { .Task = MyTask1, .TaskStatus = TASK_RUN, .GroupID = 1  },
  63  *              { .Task = MyTask2, .TaskStatus = TASK_RUN, .GroupID = 1  },
  64  *      }
  65  *
  66  *      int main(void)
  67  *      {
  68  *              Scheduler_Start();
  69  *      }
  70  *
  71  *      TASK(MyTask1)
  72  *      {
  73  *              // Implementation Here
  74  *      }
  75  *
  76  *      TASK(MyTask2)
  77  *      {
  78  *              // Implementation Here
  79  *      }
  80  *  \endcode
  81  *
  82  *  @{
  83  */
  84
  85 #ifndef __SCHEDULER_H__
  86 #define __SCHEDULER_H__
  87
  88         /* Includes: */
  89         #if defined(__AVR32__)
  90                 #include <avr32/io.h>
  91                 #include <stdbool.h>
  92         #else
  93                 #include <avr/io.h>
  94                 #include <util/atomic.h>
  95                 #include <stdbool.h>
  96         #endif
  97
  98         #include "../Common/Common.h"
  99
 100         /* Enable C linkage for C++ Compilers: */
 101                 #if defined(__cplusplus)
 102                         extern "C" {
 103                 #endif
 104
 105         /* Public Interface - May be used in end-application: */
 106                 /* Macros: */
 107                         /** Creates a new scheduler task body or prototype. Should be used in the form:
 108                          *  \code
 109                          *      TASK(TaskName); // Prototype
 110                          *
 111                          *      TASK(TaskName)
 112                          *      {
 113                          *           // Task body
 114                          *      }
 115                          *  \endcode
 116                          */
 117                         #define TASK(name)                        void name (void)
 118
 119                         /** Defines a task list array, containing one or more task entries of the type TaskEntry_t. Each task list
 120                          *  should be encased in curly braces and ended with a comma.
 121                          *
 122                          *  Usage Example:
 123                          *  \code
 124                          *      TASK_LIST
 125                          *      {
 126                          *           { .Task = MyTask1, .TaskStatus = TASK_RUN, .GroupID = 1 },
 127                          *           // More task entries here
 128                          *      }
 129                          *  \endcode
 130                          */
 131                         #define TASK_LIST                         TaskEntry_t Scheduler_TaskList[] =
 132
 133                         /** Constant, giving the maximum delay in scheduler ticks which can be stored in a variable of type
 134                          *  SchedulerDelayCounter_t.
 135                          */
 136                         #define TASK_MAX_DELAY                    (MAX_DELAYCTR_COUNT - 1)
 137
 138                         /** Task status mode constant, for passing to Scheduler_SetTaskMode() or Scheduler_SetGroupTaskMode(). */
 139                         #define TASK_RUN                          true
 140
 141                         /** Task status mode constant, for passing to Scheduler_SetTaskMode() or Scheduler_SetGroupTaskMode(). */
 142                         #define TASK_STOP                         false
 143
 144                 /* Pseudo-Function Macros: */
 145                         #if defined(__DOXYGEN__)
 146                                 /** Starts the scheduler in its infinite loop, executing running tasks. This should be placed at the end
 147                                  *  of the user application's main() function, as it can never return to the calling function.
 148                                  */
 149                                 void Scheduler_Start(void);
 150
 151                                 /** Initializes the scheduler so that the scheduler functions can be called before the scheduler itself
 152                                  *  is started. This must be executed before any scheduler function calls other than Scheduler_Start(),
 153                                  *  and can be omitted if no such functions could be called before the scheduler is started.
 154                                  */
 155                                 void Scheduler_Init(void);
 156                         #else
 157                                 #define Scheduler_Start()                 Scheduler_GoSchedule(TOTAL_TASKS);
 158
 159                                 #define Scheduler_Init()                  Scheduler_InitScheduler(TOTAL_TASKS);
 160                         #endif
 161
 162                 /* Type Defines: */
 163                         /** Type define for a pointer to a scheduler task. */
 164                         typedef void (*TaskPtr_t)(void);
 165
 166                         /** Type define for a variable which can hold a tick delay value for the scheduler up to the maximum delay
 167                          *  possible.
 168                          */
 169                         typedef uint16_t SchedulerDelayCounter_t;
 170
 171                         /** Structure for holding a single task's information in the scheduler task list. */
 172                         typedef struct
 173                         {
 174                                 TaskPtr_t Task;       /**< Pointer to the task to execute. */
 175                                 bool      TaskStatus; /**< Status of the task (either TASK_RUN or TASK_STOP). */
 176                                 uint8_t   GroupID;    /**< Group ID of the task so that its status can be changed as a group. */
 177                         } TaskEntry_t;
 178
 179                 /* Global Variables: */
 180                         /** Task entry list, containing the scheduler tasks, task statuses and group IDs. Each entry is of type
 181                          *  TaskEntry_t and can be manipulated as desired, although it is preferential that the proper Scheduler
 182                          *  functions should be used instead of direct manipulation.
 183                          */
 184                         extern          TaskEntry_t               Scheduler_TaskList[];
 185
 186                         /** Contains the total number of tasks in the task list, irrespective of if the task's status is set to
 187                          *  TASK_RUN or TASK_STOP.
 188                          *
 189                          *  \note This value should be treated as read-only, and never altered in user-code.
 190                          */
 191                         extern volatile uint8_t                   Scheduler_TotalTasks;
 192
 193                         /**  Contains the current scheduler tick count, for use with the delay functions. If the delay functions
 194                          *   are used in the user code, this should be incremented each tick period so that the delays can be
 195                          *   calculated.
 196                          */
 197                         extern volatile SchedulerDelayCounter_t   Scheduler_TickCounter;
 198
 199                 /* Inline Functions: */
 200                         /** Resets the delay counter value to the current tick count. This should be called to reset the period
 201                          *  for a delay in a task which is dependant on the current tick value.
 202                          *
 203                          *  \param[out] DelayCounter  Counter which is storing the starting tick count for a given delay.
 204                          */
 205                         static inline void Scheduler_ResetDelay(SchedulerDelayCounter_t* const DelayCounter)
 206                                                                 ATTR_NON_NULL_PTR_ARG(1) ATTR_ALWAYS_INLINE;
 207                         static inline void Scheduler_ResetDelay(SchedulerDelayCounter_t* const DelayCounter)
 208                         {
 209                                 ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
 210                                 {
 211                                         *DelayCounter = Scheduler_TickCounter;
 212                                 }
 213                         }
 214
 215                 /* Function Prototypes: */
 216                         /** Determines if the given tick delay has elapsed, based on the given .
 217                          *
 218                          *  \param[in] Delay         The delay to test for, measured in ticks
 219                          *  \param[in] DelayCounter  The counter which is storing the starting tick value for the delay
 220                          *
 221                          *  \return Boolean true if the delay has elapsed, false otherwise
 222                          *
 223                          *  Usage Example:
 224                          *  \code
 225                          *      static SchedulerDelayCounter_t DelayCounter = 10000; // Force immediate run on start-up
 226                          *
 227                          *      // Task runs every 10000 ticks, 10 seconds for this demo
 228                          *      if (Scheduler_HasDelayElapsed(10000, &DelayCounter))
 229                          *      {
 230                          *           // Code to execute after delay interval elapsed here
 231                          *      }
 232                          *  \endcode
 233                          */
 234                         bool Scheduler_HasDelayElapsed(const uint16_t Delay,
 235                                                        SchedulerDelayCounter_t* const DelayCounter)
 236                                                                                    ATTR_WARN_UNUSED_RESULT ATTR_NON_NULL_PTR_ARG(2);
 237
 238                         /** Sets the task mode for a given task.
 239                          *
 240                          *  \param[in] Task        Name of the task whose status is to be changed
 241                          *  \param[in] TaskStatus  New task status for the task (TASK_RUN or TASK_STOP)
 242                          */
 243                         void Scheduler_SetTaskMode(const TaskPtr_t Task, const bool TaskStatus);
 244
 245                         /** Sets the task mode for a given task group ID, allowing for an entire group of tasks to have their
 246                          *  statuses changed at once.
 247                          *
 248                          *  \param[in] GroupID     Value of the task group ID whose status is to be changed
 249                          *  \param[in] TaskStatus  New task status for tasks in the specified group (TASK_RUN or TASK_STOP)
 250                          */
 251                         void Scheduler_SetGroupTaskMode(const uint8_t GroupID, const bool TaskStatus);
 252
 253         /* Private Interface - For use in library only: */
 254         #if !defined(__DOXYGEN__)
 255                 /* Macros: */
 256                         #define TOTAL_TASKS                       (sizeof(Scheduler_TaskList) / sizeof(TaskEntry_t))
 257                         #define MAX_DELAYCTR_COUNT                0xFFFF
 258
 259                 /* Inline Functions: */
 260                         static inline void Scheduler_InitScheduler(const uint8_t TotalTasks) ATTR_ALWAYS_INLINE;
 261                         static inline void Scheduler_InitScheduler(const uint8_t TotalTasks)
 262                         {
 263                                 Scheduler_TotalTasks = TotalTasks;
 264                         }
 265
 266                         static inline void Scheduler_GoSchedule(const uint8_t TotalTasks) ATTR_NO_RETURN ATTR_ALWAYS_INLINE ATTR_DEPRECATED;
 267                         static inline void Scheduler_GoSchedule(const uint8_t TotalTasks)
 268                         {
 269                                 Scheduler_InitScheduler(TotalTasks);
 270
 271                                 for (;;)
 272                                 {
 273                                         TaskEntry_t* CurrTask = &Scheduler_TaskList[0];
 274
 275                                         while (CurrTask != &Scheduler_TaskList[TotalTasks])
 276                                         {
 277                                                 if (CurrTask->TaskStatus == TASK_RUN)
 278                                                   CurrTask->Task();
 279
 280                                                 CurrTask++;
 281                                         }
 282                                 }
 283                         }
 284         #endif
 285
 286         /* Disable C linkage for C++ Compilers: */
 287                 #if defined(__cplusplus)
 288                         }
 289                 #endif
 290
 291 #endif
 292
 293 /** @} */