/**
* @file rtems/score/schedulersimple.h
*
* @brief Manipulation of Threads Simple-Priority-Based Ready Queue
*
* This include file contains all the constants and structures associated
* with the manipulation of threads on a simple-priority-based ready queue.
*/
/*
* 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.org/license/LICENSE.
*/
#ifndef _RTEMS_SCORE_SCHEDULERSIMPLE_H
#define _RTEMS_SCORE_SCHEDULERSIMPLE_H
#include <rtems/score/scheduler.h>
#include <rtems/score/schedulerpriority.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @defgroup ScoreSchedulerSimple Simple Priority Scheduler
*
* @ingroup ScoreScheduler
*/
/**@{*/
#define SCHEDULER_SIMPLE_MAXIMUM_PRIORITY 255
/**
* Entry points for Scheduler Simple
*/
#define SCHEDULER_SIMPLE_ENTRY_POINTS \
{ \
_Scheduler_simple_Initialize, /* initialize entry point */ \
_Scheduler_simple_Schedule, /* schedule entry point */ \
_Scheduler_simple_Yield, /* yield entry point */ \
_Scheduler_simple_Block, /* block entry point */ \
_Scheduler_simple_Unblock, /* unblock entry point */ \
_Scheduler_simple_Change_priority, /* change priority entry point */ \
_Scheduler_default_Map_priority, /* map priority entry point */ \
_Scheduler_default_Unmap_priority, /* unmap priority entry point */ \
SCHEDULER_OPERATION_DEFAULT_ASK_FOR_HELP \
_Scheduler_default_Node_initialize, /* node initialize entry point */ \
_Scheduler_default_Node_destroy, /* node destroy entry point */ \
_Scheduler_default_Update_priority, /* update priority entry point */ \
_Scheduler_default_Release_job, /* new period of task */ \
_Scheduler_default_Tick, /* tick entry point */ \
_Scheduler_default_Start_idle /* start idle entry point */ \
SCHEDULER_OPERATION_DEFAULT_GET_SET_AFFINITY \
}
/**
* @brief Simple scheduler context.
*/
typedef struct {
/**
* @brief Basic scheduler context.
*/
Scheduler_Context Base;
/**
* @brief One ready queue for all ready threads.
*/
Chain_Control Ready;
} Scheduler_simple_Context;
/**
* @brief Initialize simple scheduler.
*
* This routine initializes the simple scheduler.
*/
void _Scheduler_simple_Initialize( const Scheduler_Control *scheduler );
/**
* This routine sets the heir thread to be the next ready thread
* on the ready queue by getting the first node in the scheduler
* information.
*
* @param[in] scheduler The scheduler instance.
* @param[in] the_thread causing the scheduling operation.
*/
void _Scheduler_simple_Schedule(
const Scheduler_Control *scheduler,
Thread_Control *the_thread
);
/**
* @brief Invoked when a thread wishes to voluntarily
* transfer control of the processor to another thread in the queue.
*
* This routine is invoked when a thread wishes to voluntarily
* transfer control of the processor to another thread in the queue.
* It will remove the specified THREAD from the scheduler.informaiton
* (where the ready queue is stored) and place it immediately at the
* between the last entry of its priority and the next priority thread.
* 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.
*
* @param[in] scheduler The scheduler instance.
* @param[in,out] the_thread The yielding thread.
*/
Scheduler_Void_or_thread _Scheduler_simple_Yield(
const Scheduler_Control *scheduler,
Thread_Control *the_thread
);
/**
* @brief Remove a simple-priority-based thread from the queue.
*
* 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] scheduler The scheduler instance.
* @param[in] the_thread is the thread that is to be blocked
*/
void _Scheduler_simple_Block(
const Scheduler_Control *scheduler,
Thread_Control *the_thread
);
/**
* @brief Unblock a simple-priority-based thread.
*
* 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] scheduler The scheduler instance.
* @param[in] the_thread is the thread that is to be unblocked
*/
Scheduler_Void_or_thread _Scheduler_simple_Unblock(
const Scheduler_Control *scheduler,
Thread_Control *the_thread
);
Scheduler_Void_or_thread _Scheduler_simple_Change_priority(
const Scheduler_Control *scheduler,
Thread_Control *the_thread,
Priority_Control new_priority,
bool prepend_it
);
/**@}*/
#ifdef __cplusplus
}
#endif
#endif
/* end of include file */
