/** * @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.org/license/LICENSE. */ #ifndef _RTEMS_SCORE_SCHEDULERPRIORITY_H #define _RTEMS_SCORE_SCHEDULERPRIORITY_H #include #include #include #ifdef __cplusplus extern "C" { #endif /** * @defgroup ScoreSchedulerDPS Deterministic Priority Scheduler * * @ingroup ScoreScheduler */ /**@{*/ #if defined(__RTEMS_HAVE_SYS_CPUSET_H__) && defined(RTEMS_SMP) #define SCHEDULER_PRIORITY_ADDITIONAL_SMP_ENTRY_POINTS \ _Scheduler_default_Get_affinity, /* get affinity entry point */ \ _Scheduler_default_Set_affinity /* set affinity entry point */ #else #define SCHEDULER_PRIORITY_ADDITIONAL_SMP_ENTRY_POINTS #endif /** * 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_default_Allocate, /* allocate entry point */ \ _Scheduler_default_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_default_Release_job, /* new period of task */ \ _Scheduler_default_Tick, /* tick entry point */ \ _Scheduler_default_Start_idle, /* start idle entry point */ \ SCHEDULER_PRIORITY_ADDITIONAL_SMP_ENTRY_POINTS \ } typedef struct { /** * @brief Basic scheduler context. */ Scheduler_Context Base; /** * @brief Bit map to indicate non-empty ready queues. */ Priority_bit_map_Control Bit_map; /** * @brief One ready queue per priority level. */ Chain_Control Ready[ 0 ]; } Scheduler_priority_Context; /** * 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( const Scheduler_Control *scheduler ); /** * @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( const Scheduler_Control *scheduler, 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( const Scheduler_Control *scheduler, 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( const Scheduler_Control *scheduler, 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( const Scheduler_Control *scheduler, 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( const Scheduler_Control *scheduler, Thread_Control *the_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( const Scheduler_Control *scheduler, 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( const Scheduler_Control *scheduler, 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( const Scheduler_Control *scheduler, Thread_Control *the_thread ); /** * @brief Compare two priorities. * * This routine compares two priorities. */ int _Scheduler_priority_Priority_compare( Priority_Control p1, Priority_Control p2 ); /**@}*/ #ifdef __cplusplus } #endif #endif /* end of include file */