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Diffstat (limited to 'LUFA/Scheduler/Scheduler.h')
| -rw-r--r-- | LUFA/Scheduler/Scheduler.h | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/LUFA/Scheduler/Scheduler.h b/LUFA/Scheduler/Scheduler.h new file mode 100644 index 0000000..a6f8ddd --- /dev/null +++ b/LUFA/Scheduler/Scheduler.h @@ -0,0 +1,313 @@ +/*
+ LUFA Library
+ Copyright (C) Dean Camera, 2010.
+
+ dean [at] fourwalledcubicle [dot] com
+ www.lufa-lib.org
+*/
+
+/*
+ Copyright 2010 Dean Camera (dean [at] fourwalledcubicle [dot] com)
+
+ Permission to use, copy, modify, distribute, and sell this
+ software and its documentation for any purpose is hereby granted
+ without fee, provided that the above copyright notice appear in
+ all copies and that both that the copyright notice and this
+ permission notice and warranty disclaimer appear in supporting
+ documentation, and that the name of the author not be used in
+ advertising or publicity pertaining to distribution of the
+ software without specific, written prior permission.
+
+ The author disclaim all warranties with regard to this
+ software, including all implied warranties of merchantability
+ and fitness. In no event shall the author be liable for any
+ special, indirect or consequential damages or any damages
+ whatsoever resulting from loss of use, data or profits, whether
+ in an action of contract, negligence or other tortious action,
+ arising out of or in connection with the use or performance of
+ this software.
+*/
+
+/** \file
+ * \brief Simple round-robbin pseudo-task scheduler.
+ *
+ * Simple round-robbin cooperative scheduler for use in basic projects where non real-time tasks need
+ * to be executed. Each task is executed in sequence, and can be enabled or disabled individually or as a group.
+ *
+ * \deprecated This module is deprecated and will be removed in a future library release.
+ */
+
+/** @defgroup Group_Scheduler Simple Task Scheduler - LUFA/Scheduler/Scheduler.h
+ *
+ * \deprecated This module is deprecated and will be removed in a future library release.
+ *
+ * \section Sec_Dependencies Module Source Dependencies
+ * The following files must be built with any user project that uses this module:
+ * - LUFA/Scheduler/Scheduler.c <i>(Makefile source module name: LUFA_SRC_SCHEDULER)</i>
+ *
+ * \section Module Description
+ * Simple round-robbin cooperative scheduler for use in basic projects where non real-time tasks need
+ * to be executed. Each task is executed in sequence, and can be enabled or disabled individually or as a group.
+ *
+ * For a task to yield it must return, thus each task should have persistent data marked with the static attribute.
+ *
+ * Each LUFA scheduler task should be written similar to an ISR; it should execute quickly (so that no one task
+ * hogs the processor, preventing another from running before some sort of timeout is exceeded). Unlike normal RTOS
+ * tasks, each LUFA scheduler task is a regular function, and thus must be designed to be called, and designed to
+ * return to the calling scheduler function repeatedly. Data which must be preserved between task calls should be
+ * declared as global or (preferably) as a static local variable inside the task.
+ *
+ * The scheduler consists of a task list, listing all the tasks which can be executed by the scheduler. Once started,
+ * each task is then called one after another, unless the task is stopped by another running task or interrupt.
+ *
+ * Usage Example:
+ * \code
+ * #include <LUFA/Scheduler/Scheduler.h>
+ *
+ * TASK(MyTask1); // Task prototype
+ * TASK(MyTask2); // Task prototype
+ *
+ * TASK_LIST
+ * {
+ * { .Task = MyTask1, .TaskStatus = TASK_RUN, .GroupID = 1 },
+ * { .Task = MyTask2, .TaskStatus = TASK_RUN, .GroupID = 1 },
+ * }
+ *
+ * int main(void)
+ * {
+ * Scheduler_Init();
+ *
+ * // Other initialisation here
+ *
+ * Scheduler_Start();
+ * }
+ *
+ * TASK(MyTask1)
+ * {
+ * // Task implementation here
+ * }
+ *
+ * TASK(MyTask2)
+ * {
+ * // Task implementation here
+ * }
+ * \endcode
+ *
+ * If desired, the LUFA scheduler <b>does not need to be used</b> in a LUFA powered application. A more conventional
+ * approach to application design can be used, or a proper scheduling RTOS inserted in the place of the LUFA scheduler.
+ * In the case of the former the USB task must be run manually repeatedly to maintain USB communications, and in the
+ * case of the latter a proper RTOS task must be set up to do the same.
+ *
+ * @{
+ */
+
+#ifndef __SCHEDULER_H__
+#define __SCHEDULER_H__
+
+ /* Includes: */
+ #include <stdint.h>
+ #include <stdbool.h>
+
+ #include <util/atomic.h>
+
+ #include "../Common/Common.h"
+
+ /* Enable C linkage for C++ Compilers: */
+ #if defined(__cplusplus)
+ extern "C" {
+ #endif
+
+ /* Public Interface - May be used in end-application: */
+ /* Macros: */
+ /** Creates a new scheduler task body or prototype. Should be used in the form:
+ * \code
+ * TASK(TaskName); // Prototype
+ *
+ * TASK(TaskName)
+ * {
+ * // Task body
+ * }
+ * \endcode
+ */
+ #define TASK(name) void name (void)
+
+ /** Defines a task list array, containing one or more task entries of the type TaskEntry_t. Each task list
+ * should be encased in curly braces and ended with a comma.
+ *
+ * Usage Example:
+ * \code
+ * TASK_LIST
+ * {
+ * { .Task = MyTask1, .TaskStatus = TASK_RUN, .GroupID = 1 },
+ * // More task entries here
+ * }
+ * \endcode
+ */
+ #define TASK_LIST TaskEntry_t Scheduler_TaskList[] =
+
+ /** Constant, giving the maximum delay in scheduler ticks which can be stored in a variable of type
+ * \ref SchedulerDelayCounter_t.
+ */
+ #define TASK_MAX_DELAY (MAX_DELAYCTR_COUNT - 1)
+
+ /** Task status mode constant, for passing to \ref Scheduler_SetTaskMode() or \ref Scheduler_SetGroupTaskMode(). */
+ #define TASK_RUN true
+
+ /** Task status mode constant, for passing to \ref Scheduler_SetTaskMode() or \ref Scheduler_SetGroupTaskMode(). */
+ #define TASK_STOP false
+
+ /* Pseudo-Function Macros: */
+ #if defined(__DOXYGEN__)
+ /** Starts the scheduler in its infinite loop, executing running tasks. This should be placed at the end
+ * of the user application's main() function, as it can never return to the calling function.
+ */
+ void Scheduler_Start(void);
+
+ /** Initialises the scheduler so that the scheduler functions can be called before the scheduler itself
+ * is started. This must be executed before any scheduler function calls other than Scheduler_Start(),
+ * and can be omitted if no such functions could be called before the scheduler is started.
+ */
+ void Scheduler_Init(void);
+ #else
+ #define Scheduler_Start() Scheduler_GoSchedule(TOTAL_TASKS);
+ #define Scheduler_Init() Scheduler_InitScheduler(TOTAL_TASKS);
+ #endif
+
+ /* Type Defines: */
+ /** Type define for a pointer to a scheduler task. */
+ typedef void (*TaskPtr_t)(void);
+
+ /** Type define for a variable which can hold a tick delay value for the scheduler up to the maximum delay
+ * possible.
+ */
+ typedef uint16_t SchedulerDelayCounter_t;
+
+ /** \brief Scheduler Task List Entry Structure.
+ *
+ * Structure for holding a single task's information in the scheduler task list.
+ */
+ typedef struct
+ {
+ TaskPtr_t Task; /**< Pointer to the task to execute. */
+ bool TaskStatus; /**< Status of the task (either TASK_RUN or TASK_STOP). */
+ uint8_t GroupID; /**< Group ID of the task so that its status can be changed as a group. */
+ } TaskEntry_t;
+
+ /* Global Variables: */
+ /** Task entry list, containing the scheduler tasks, task statuses and group IDs. Each entry is of type
+ * TaskEntry_t and can be manipulated as desired, although it is preferential that the proper Scheduler
+ * functions should be used instead of direct manipulation.
+ */
+ exter TaskEntry_t Scheduler_TaskList[];
+
+ /** Contains the total number of tasks in the task list, irrespective of if the task's status is set to
+ * \ref TASK_RUN or \ref TASK_STOP.
+ *
+ * \note This value should be treated as read-only, and never altered in user-code.
+ */
+ extern volatile uint8_t Scheduler_TotalTasks;
+
+ /** Contains the current scheduler tick count, for use with the delay functions. If the delay functions
+ * are used in the user code, this should be incremented each tick period so that the delays can be
+ * calculated.
+ */
+ extern volatile SchedulerDelayCounter_t Scheduler_TickCounter;
+
+ /* Inline Functions: */
+ /** Resets the delay counter value to the current tick count. This should be called to reset the period
+ * for a delay in a task which is dependant on the current tick value.
+ *
+ * \param[out] DelayCounter Counter which is storing the starting tick count for a given delay.
+ */
+ static inline void Scheduler_ResetDelay(SchedulerDelayCounter_t* const DelayCounter)
+ ATTR_NON_NULL_PTR_ARG(1) ATTR_ALWAYS_INLINE;
+ static inline void Scheduler_ResetDelay(SchedulerDelayCounter_t* const DelayCounter)
+ {
+ ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
+ {
+ *DelayCounter = Scheduler_TickCounter;
+ }
+ }
+
+ /* Function Prototypes: */
+ /** Determines if the given tick delay has elapsed, based on the given delay period and tick counter value.
+ *
+ * \param[in] Delay The delay to test for, measured in ticks.
+ * \param[in] DelayCounter The counter which is storing the starting tick value for the delay.
+ *
+ * \return Boolean true if the delay has elapsed, false otherwise.
+ *
+ * Usage Example:
+ * \code
+ * static SchedulerDelayCounter_t DelayCounter = 10000; // Force immediate run on start-up
+ *
+ * // Task runs every 10000 ticks, 10 seconds for this demo
+ * if (Scheduler_HasDelayElapsed(10000, &DelayCounter))
+ * {
+ * // Code to execute after delay interval elapsed here
+ * }
+ * \endcode
+ */
+ bool Scheduler_HasDelayElapsed(const uint16_t Delay,
+ SchedulerDelayCounter_t* const DelayCounter)
+ ATTR_WARN_UNUSED_RESULT ATTR_NON_NULL_PTR_ARG(2);
+
+ /** Sets the task mode for a given task.
+ *
+ * \param[in] Task Name of the task whose status is to be changed.
+ * \param[in] TaskStatus New task status for the task (\ref TASK_RUN or \ref TASK_STOP).
+ */
+ void Scheduler_SetTaskMode(const TaskPtr_t Task,
+ const bool TaskStatus);
+
+ /** Sets the task mode for a given task group ID, allowing for an entire group of tasks to have their
+ * statuses changed at once.
+ *
+ * \param[in] GroupID Value of the task group ID whose status is to be changed.
+ * \param[in] TaskStatus New task status for tasks in the specified group (\ref TASK_RUN or \ref TASK_STOP).
+ */
+ void Scheduler_SetGroupTaskMode(const uint8_t GroupID,
+ const bool TaskStatus);
+
+ /* Private Interface - For use in library only: */
+ #if !defined(__DOXYGEN__)
+ /* Macros: */
+ #define TOTAL_TASKS (sizeof(Scheduler_TaskList) / sizeof(TaskEntry_t))
+ #define MAX_DELAYCTR_COUNT 0xFFFF
+
+ /* Inline Functions: */
+ static inline void Scheduler_InitScheduler(const uint8_t TotalTasks) ATTR_ALWAYS_INLINE;
+ static inline void Scheduler_InitScheduler(const uint8_t TotalTasks)
+ {
+ Scheduler_TotalTasks = TotalTasks;
+ }
+
+ static inline void Scheduler_GoSchedule(const uint8_t TotalTasks) ATTR_NO_RETURN ATTR_ALWAYS_INLINE ATTR_DEPRECATED;
+ static inline void Scheduler_GoSchedule(const uint8_t TotalTasks)
+ {
+ Scheduler_InitScheduler(TotalTasks);
+
+ for (;;)
+ {
+ TaskEntry_t* CurrTask = &Scheduler_TaskList[0];
+
+ while (CurrTask != &Scheduler_TaskList[TotalTasks])
+ {
+ if (CurrTask->TaskStatus == TASK_RUN)
+ CurrTask->Task();
+
+ CurrTask++;
+ }
+ }
+ }
+ #endif
+
+ /* Disable C linkage for C++ Compilers: */
+ #if defined(__cplusplus)
+ }
+ #endif
+
+#endif
+
+/** @} */
+
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