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Diffstat (limited to 'cpukit/include/rtems/score/scheduleruniimpl.h')
-rw-r--r-- | cpukit/include/rtems/score/scheduleruniimpl.h | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/cpukit/include/rtems/score/scheduleruniimpl.h b/cpukit/include/rtems/score/scheduleruniimpl.h new file mode 100644 index 0000000000..9fe9ec394c --- /dev/null +++ b/cpukit/include/rtems/score/scheduleruniimpl.h @@ -0,0 +1,221 @@ +/* SPDX-License-Identifier: BSD-2-Clause */ + +/** + * @file + * + * @ingroup RTEMSScoreScheduler + * + * @brief This header file provides interfaces of the supporting the + * implementation of uniprocessor schedulers. + */ + +/* + * Copyright (C) 2010 Gedare Bloom. + * Copyright (C) 2011 On-Line Applications Research Corporation (OAR). + * Copyright (C) 2014, 2022 embedded brains GmbH & Co. KG + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef _RTEMS_SCORE_SCHEDULERUNIIMPL_H +#define _RTEMS_SCORE_SCHEDULERUNIIMPL_H + +#include <rtems/score/schedulerimpl.h> + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * @addtogroup RTEMSScoreScheduler + * + * @{ + */ + +/** + * @brief Updates the heir thread of the processor. + * + * @param[in, out] heir is the current heir thread. + * @param[in, out] new_heir is the new heir thread. + */ +static inline void _Scheduler_uniprocessor_Update_heir( + Thread_Control *heir, + Thread_Control *new_heir +) +{ + _Assert( heir != new_heir ); +#if defined(RTEMS_SMP) + /* + * We need this state only for _Thread_Get_CPU_time_used_locked(). Cannot + * use _Scheduler_Thread_change_state() since THREAD_SCHEDULER_BLOCKED to + * THREAD_SCHEDULER_BLOCKED state changes are illegal for the real SMP + * schedulers. + */ + heir->Scheduler.state = THREAD_SCHEDULER_BLOCKED; + new_heir->Scheduler.state = THREAD_SCHEDULER_SCHEDULED; +#endif + _Thread_Update_CPU_time_used( heir, _Thread_Get_CPU( heir ) ); + _Thread_Heir = new_heir; + _Thread_Dispatch_necessary = true; +} + +/** + * @brief Updates the heir thread of the processor if the current heir is + * not equal to the new heir thread. + * + * The update takes place even if the current heir thread is not preemptible. + * + * @param[in, out] new_heir is the new heir thread. + */ +static inline void _Scheduler_uniprocessor_Update_heir_if_necessary( + Thread_Control *new_heir +) +{ + Thread_Control *heir = _Thread_Heir; + + if ( heir != new_heir ) { + _Scheduler_uniprocessor_Update_heir( heir, new_heir ); + } +} + +/** + * @brief Updates the heir thread of the processor if the current heir thread + * is preemptible. + * + * @param[in, out] heir is the current heir thread. + * @param[in, out] new_heir is the new heir thread. + */ +static inline void _Scheduler_uniprocessor_Update_heir_if_preemptible( + Thread_Control *heir, + Thread_Control *new_heir +) +{ + if ( heir != new_heir && heir->is_preemptible ) { + _Scheduler_uniprocessor_Update_heir( heir, new_heir ); + } +} + +/** + * @brief Blocks the thread. + * + * @param scheduler is the scheduler. + * @param the_thread is the thread to block. + * @param node is the scheduler node of the thread. + * @param extract is the handler to extract the thread. + * @param get_highest_ready is the handler to get the highest ready thread. + */ +static inline void _Scheduler_uniprocessor_Block( + const Scheduler_Control *scheduler, + Thread_Control *the_thread, + Scheduler_Node *node, + void ( *extract )( + const Scheduler_Control *, + Thread_Control *, + Scheduler_Node * + ), + Thread_Control *( *get_highest_ready )( const Scheduler_Control * ) +) +{ + ( *extract )( scheduler, the_thread, node ); + + /* TODO: flash critical section? */ + + if ( _Thread_Is_heir( the_thread ) ) { + Thread_Control *highest_ready; + + highest_ready = ( *get_highest_ready )( scheduler ); + _Scheduler_uniprocessor_Update_heir( _Thread_Heir, highest_ready ); + } +} + +/** + * @brief Schedule the unblocked thread if it is the highest ready thread. + * + * @param scheduler is the scheduler. + * @param the_thread is the thread. + * @param priority is the priority of the thread. + */ +static inline void _Scheduler_uniprocessor_Unblock( + const Scheduler_Control *scheduler, + Thread_Control *the_thread, + Priority_Control priority +) +{ + Thread_Control *heir; + + heir = _Thread_Heir; + + /* + * If the thread is more important than the heir, then we have a new heir. + * This may or may not result in a context switch. If the current heir + * thread is preemptible, then we need to do a context switch. + */ + if ( priority < _Thread_Get_priority( heir ) ) { + _Scheduler_uniprocessor_Update_heir_if_preemptible( heir, the_thread ); + } +} + +/** + * @brief Schedules the highest ready thread if the current heir thread of the + * processor is preemptible. + * + * @param scheduler is the scheduler. + * @param get_highest_ready is the handler to get the highest ready thread. + */ +static inline void _Scheduler_uniprocessor_Schedule( + const Scheduler_Control *scheduler, + Thread_Control *( *get_highest_ready )( const Scheduler_Control * ) +) +{ + Thread_Control *highest_ready; + + highest_ready = ( *get_highest_ready )( scheduler ); + _Scheduler_uniprocessor_Update_heir_if_preemptible( + _Thread_Heir, + highest_ready + ); +} + +/** + * @brief Yields to the highest ready thread. + * + * @param scheduler is the scheduler. + * @param get_highest_ready is the handler to get the highest ready thread. + */ +static inline void _Scheduler_uniprocessor_Yield( + const Scheduler_Control *scheduler, + Thread_Control *( *get_highest_ready )( const Scheduler_Control * ) +) +{ + Thread_Control *highest_ready; + + highest_ready = ( *get_highest_ready )( scheduler ); + _Scheduler_uniprocessor_Update_heir_if_necessary( highest_ready ); +} + +/** @} */ + +#ifdef __cplusplus +} +#endif + +#endif /* _RTEMS_SCORE_SCHEDULERUNIIMPL_H */ |