/** * @file rtems/score/scheduleredf.h * * @brief Data Related to the Manipulation of Threads for the EDF Scheduler * * This include file contains all the constants and structures associated * with the manipulation of threads for the EDF scheduler. */ /* * Copryight (c) 2011 Petr Benes. * 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_SCHEDULEREDF_H #define _RTEMS_SCORE_SCHEDULEREDF_H #include #include #include #include #ifdef __cplusplus extern "C" { #endif /** * @defgroup ScoreSchedulerEDF EDF Scheduler * * @ingroup ScoreScheduler */ /**@{*/ #define SCHEDULER_EDF_MAXIMUM_PRIORITY 0x7fffffff /** * Entry points for the Earliest Deadline First Scheduler. */ #define SCHEDULER_EDF_ENTRY_POINTS \ { \ _Scheduler_EDF_Initialize, /* initialize entry point */ \ _Scheduler_EDF_Schedule, /* schedule entry point */ \ _Scheduler_EDF_Yield, /* yield entry point */ \ _Scheduler_EDF_Block, /* block entry point */ \ _Scheduler_EDF_Unblock, /* unblock entry point */ \ _Scheduler_EDF_Update_priority, /* update priority entry point */ \ _Scheduler_EDF_Map_priority, /* map priority entry point */ \ _Scheduler_EDF_Unmap_priority, /* unmap priority entry point */ \ SCHEDULER_OPERATION_DEFAULT_ASK_FOR_HELP \ _Scheduler_EDF_Node_initialize, /* node initialize entry point */ \ _Scheduler_default_Node_destroy, /* node destroy entry point */ \ _Scheduler_EDF_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 \ } typedef struct { /** * @brief Basic scheduler context. */ Scheduler_Context Base; /** * Top of the ready queue. */ RBTree_Control Ready; } Scheduler_EDF_Context; /** * @brief Scheduler node specialization for EDF schedulers. */ typedef struct { /** * @brief Basic scheduler node. */ Scheduler_Node Base; /** * Pointer to corresponding Thread Control Block. */ Thread_Control *thread; /** * Rbtree node related to this thread. */ RBTree_Node Node; /** * @brief The thread priority used by this scheduler instance in case no job * is released. */ Priority_Control background_priority; /** * @brief The thread priority currently used by this scheduler instance. */ Priority_Control current_priority; } Scheduler_EDF_Node; /** * @brief Initialize EDF scheduler. * * This routine initializes the EDF scheduler. * * @param[in] scheduler The scheduler instance. */ void _Scheduler_EDF_Initialize( const Scheduler_Control *scheduler ); /** * @brief Removes thread from ready 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 to be blocked. */ void _Scheduler_EDF_Block( const Scheduler_Control *scheduler, Thread_Control *the_thread ); /** * @brief Sets the heir thread to be the next ready thread * in the rbtree ready queue. * * This kernel routine sets the heir thread to be the next ready thread * in the rbtree ready queue. * * @param[in] scheduler The scheduler instance. * @param[in] the_thread being scheduled. */ void _Scheduler_EDF_Schedule( const Scheduler_Control *scheduler, Thread_Control *the_thread ); /** * @brief Initializes an EDF specific scheduler node of @a the_thread. * * @param[in] scheduler The scheduler instance. * @param[in] the_thread being initialized. * @param[in] priority The thread priority. */ void _Scheduler_EDF_Node_initialize( const Scheduler_Control *scheduler, Thread_Control *the_thread, Priority_Control priority ); /** * @brief Adds @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] scheduler The scheduler instance. * @param[in] the_thread will be unblocked. */ Scheduler_Void_or_thread _Scheduler_EDF_Unblock( const Scheduler_Control *scheduler, Thread_Control *the_thread ); Scheduler_Void_or_thread _Scheduler_EDF_Update_priority( const Scheduler_Control *scheduler, Thread_Control *the_thread ); Priority_Control _Scheduler_EDF_Map_priority( const Scheduler_Control *scheduler, Priority_Control priority ); Priority_Control _Scheduler_EDF_Unmap_priority( const Scheduler_Control *scheduler, Priority_Control priority ); /** * @brief invoked when a thread wishes to voluntarily * transfer control of the processor to another thread * with equal deadline. * * This routine is invoked when a thread wishes to voluntarily * transfer control of the processor to another thread in the queue with * equal deadline. This does not have to happen very often. * * This routine will remove the specified THREAD from the ready queue * and place it back. The rbtree ready queue is responsible for FIFO ordering * in such a case. * * @param[in] scheduler The scheduler instance. * @param[in,out] the_thread The yielding thread. */ Scheduler_Void_or_thread _Scheduler_EDF_Yield( const Scheduler_Control *scheduler, Thread_Control *the_thread ); /** * @brief Called when a new job of task is released. * * This routine is called when a new job of task is released. * It is called only from Rate Monotonic manager in the beginning * of new period. * * @param[in] scheduler The scheduler instance. * @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, thus a running task * has to be suspended. */ void _Scheduler_EDF_Release_job ( const Scheduler_Control *scheduler, Thread_Control *the_thread, uint64_t deadline ); #ifdef __cplusplus } #endif /**@}*/ #endif /* end of include file */