/**
* @file rtems/score/schedulerpriority.h
*
* @brief Thread Manipulation with the Priority-Based Scheduler
*
* This include file contains all the constants and structures associated
* with the manipulation of threads for the priority-based scheduler.
*/
/*
* Copryight (c) 2010 Gedare Bloom.
* Copyright (C) 2011 On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*/
#ifndef _RTEMS_SCORE_SCHEDULERPRIORITY_H
#define _RTEMS_SCORE_SCHEDULERPRIORITY_H
#include <rtems/score/chain.h>
#include <rtems/score/priority.h>
#include <rtems/score/scheduler.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @defgroup ScoreSchedulerDPS Deterministic Priority-based Scheduler
*
* @ingroup ScoreScheduler
*/
/**@{*/
/**
* Entry points for the Deterministic Priority Based Scheduler.
*/
#define SCHEDULER_PRIORITY_ENTRY_POINTS \
{ \
_Scheduler_priority_Initialize, /* initialize entry point */ \
_Scheduler_priority_Schedule, /* schedule entry point */ \
_Scheduler_priority_Yield, /* yield entry point */ \
_Scheduler_priority_Block, /* block entry point */ \
_Scheduler_priority_Unblock, /* unblock entry point */ \
_Scheduler_priority_Allocate, /* allocate entry point */ \
_Scheduler_priority_Free, /* free entry point */ \
_Scheduler_priority_Update, /* update entry point */ \
_Scheduler_priority_Enqueue, /* enqueue entry point */ \
_Scheduler_priority_Enqueue_first, /* enqueue_first entry point */ \
_Scheduler_priority_Extract, /* extract entry point */ \
_Scheduler_priority_Priority_compare, /* compares two priorities */ \
_Scheduler_priority_Release_job, /* new period of task */ \
_Scheduler_default_Tick, /* tick entry point */ \
_Scheduler_default_Start_idle /* start idle entry point */ \
}
/**
* Per-thread data related to the _Scheduler_PRIORITY scheduling policy.
*/
typedef struct {
/** This field points to the Ready FIFO for this thread's priority. */
Chain_Control *ready_chain;
/** This field contains precalculated priority map indices. */
Priority_bit_map_Information Priority_map;
} Scheduler_priority_Per_thread;
/**
* @brief Initializes the priority scheduler.
* This routine initializes the priority scheduler.
*/
void _Scheduler_priority_Initialize(void);
/**
* @brief Removes @a the_thread from the scheduling decision.
*
* This routine removes @a the_thread from the scheduling decision,
* that is, removes it from the ready queue. It performs
* any necessary scheduling operations including the selection of
* a new heir thread.
*
* @param[in] the_thread is the thread to be blocked
*/
void _Scheduler_priority_Block(
Thread_Control *the_thread
);
/**
* @brief Sets the heir thread to be the next ready thread.
*
* This kernel routine sets the heir thread to be the next ready thread
* by invoking the_scheduler->ready_queue->operations->first().
*/
void _Scheduler_priority_Schedule(void);
/**
* @brief Allocates @a the_thread->scheduler.
*
* This routine allocates @a the_thread->scheduler.
*
* @param[in] the_thread is the thread the scheduler is allocating
* management memory for
*/
void * _Scheduler_priority_Allocate(
Thread_Control *the_thread
);
/**
* @brief Frees @a the_thread->scheduler.
*
* This routine frees @a the_thread->scheduler.
*
* @param[in] the_thread is the thread whose scheduler specific information
* will be deallocated.
*/
void _Scheduler_priority_Free(
Thread_Control *the_thread
);
/**
* @brief Update the scheduler priority.
* This routine updates @a the_thread->scheduler based on @a the_scheduler
* structures and thread state.
*
* @param[in] the_thread will have its scheduler specific information
* structure updated.
*/
void _Scheduler_priority_Update(
Thread_Control *the_thread
);
/**
* @brief Add @a the_thread to the scheduling decision.
*
* This routine adds @a the_thread to the scheduling decision,
* that is, adds it to the ready queue and
* updates any appropriate scheduling variables, for example the heir thread.
*
* @param[in] the_thread will be unblocked
*/
void _Scheduler_priority_Unblock(
Thread_Control *the_thread
);
/**
* @brief The specified THREAD yields.
*
* This routine is invoked when a thread wishes to voluntarily
* transfer control of the processor to another thread in the queue.
*
* This routine will remove the specified THREAD from the ready queue
* and place it immediately at the rear of this chain. Reset timeslice
* and yield the processor functions both use this routine, therefore if
* reset is true and this is the only thread on the queue then the
* timeslice counter is reset. The heir THREAD will be updated if the
* running is also the currently the heir.
*
* - INTERRUPT LATENCY:
* + ready chain
* + select heir
*
* @param[in,out] thread The yielding thread.
*/
void _Scheduler_priority_Yield( Thread_Control *thread );
/**
* @brief Puts @a the_thread on to the priority-based ready queue.
*
* This routine puts @a the_thread on to the priority-based ready queue.
*
* @param[in] the_thread will be enqueued at the TAIL of its priority.
*/
void _Scheduler_priority_Enqueue(
Thread_Control *the_thread
);
/**
* @brief Puts @a the_thread to the head of the ready queue.
*
* This routine puts @a the_thread to the head of the ready queue.
* For priority-based ready queues, the thread will be the first thread
* at its priority level.
*
* @param[in] the_thread will be enqueued at the HEAD of its priority.
*/
void _Scheduler_priority_Enqueue_first(
Thread_Control *the_thread
);
/**
* @brief Remove a specific thread from scheduler.
*
* This routine removes a specific thread from the scheduler's set
* of ready threads.
*
* @param[in] the_thread will be extracted from the ready set.
*/
void _Scheduler_priority_Extract(
Thread_Control *the_thread
);
/**
* @brief Compare two priorities.
*
* This routine compares two priorities.
*/
int _Scheduler_priority_Priority_compare(
Priority_Control p1,
Priority_Control p2
);
/**
* @brief Called when a new job of task is released.
*
* This routine is called when a new job of task is released.
*
* @param[in] the_thread is the owner of the job.
* @param[in] deadline of the new job from now. If equal to 0,
* the job was cancelled or deleted.
*/
void _Scheduler_priority_Release_job (
Thread_Control *the_thread,
uint32_t deadline
);
/**
* This is the major bit map.
*/
extern volatile Priority_bit_map_Control _Priority_Major_bit_map;
/**
* This is the minor bit map.
*/
extern Priority_bit_map_Control _Priority_Bit_map[16] CPU_STRUCTURE_ALIGNMENT;
#ifndef __RTEMS_APPLICATION__
#include <rtems/score/schedulerpriority.inl>
#endif
#ifdef __cplusplus
}
#endif
/**@}*/
#endif
/* end of include file */
