diff options
Diffstat (limited to 'cpukit/include/rtems/score/scheduler.h')
| -rw-r--r-- | cpukit/include/rtems/score/scheduler.h | 194 |
1 files changed, 141 insertions, 53 deletions
diff --git a/cpukit/include/rtems/score/scheduler.h b/cpukit/include/rtems/score/scheduler.h index da1e030ab8..d0fe2a8626 100644 --- a/cpukit/include/rtems/score/scheduler.h +++ b/cpukit/include/rtems/score/scheduler.h @@ -1,3 +1,5 @@ +/* SPDX-License-Identifier: BSD-2-Clause */ + /** * @file * @@ -12,9 +14,26 @@ * Copyright (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. + * 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_SCHEDULER_H @@ -135,6 +154,61 @@ typedef struct { ); /** + * @brief Makes the node sticky. + * + * This operation is used by _Thread_Priority_update_and_make_sticky(). It + * is only called for the scheduler node of the home scheduler. + * + * Uniprocessor schedulers schould provide + * _Scheduler_default_Sticky_do_nothing() for this operation. + * + * SMP schedulers should provide this operation using + * _Scheduler_SMP_Make_sticky(). + * + * The make and clean sticky operations are an optimization to simplify the + * control flow in the update priority operation. The update priority + * operation is used for all scheduler nodes and not just the scheduler node + * of home schedulers. The update priority operation is a commonly used + * operations together with block and unblock. The make and clean sticky + * operations are used only in specific scenarios. + * + * @param scheduler is the scheduler of the node. + * + * @param[in, out] the_thread is the thread owning the node. + * + * @param[in, out] node is the scheduler node to make sticky. + */ + void ( *make_sticky )( + const Scheduler_Control *scheduler, + Thread_Control *the_thread, + Scheduler_Node *node + ); + + /** + * @brief Cleans the sticky property from the node. + * + * This operation is used by _Thread_Priority_update_and_clean_sticky(). It + * is only called for the scheduler node of the home scheduler. + * + * Uniprocessor schedulers schould provide + * _Scheduler_default_Sticky_do_nothing() for this operation. + * + * SMP schedulers should provide this operation using + * _Scheduler_SMP_Clean_sticky(). + * + * @param scheduler is the scheduler of the node. + * + * @param[in, out] the_thread is the thread owning the node. + * + * @param[in, out] node is the scheduler node to clean the sticky property. + */ + void ( *clean_sticky )( + const Scheduler_Control *scheduler, + Thread_Control *the_thread, + Scheduler_Node *node + ); + + /** * @brief Pin thread operation. * * @param[in] scheduler The scheduler instance of the specified processor. @@ -217,9 +291,6 @@ typedef struct { Thread_queue_Context * ); - /** @see _Scheduler_Tick() */ - void ( *tick )( const Scheduler_Control *, Thread_Control * ); - /** @see _Scheduler_Start_idle() */ void ( *start_idle )( const Scheduler_Control *, @@ -245,12 +316,12 @@ typedef struct { * this structure at the begin of its context structure. */ typedef struct Scheduler_Context { +#if defined(RTEMS_SMP) /** * @brief Lock to protect this scheduler instance. */ - ISR_LOCK_MEMBER( Lock ) + ISR_lock_Control Lock; -#if defined(RTEMS_SMP) /** * @brief The set of processors owned by this scheduler instance. */ @@ -403,26 +474,16 @@ Priority_Control _Scheduler_default_Unmap_priority( /** * @brief Does nothing. * - * @param scheduler This parameter is unused. - * @param the_thread This parameter is unused. - * @param node This parameter is unused. + * This default implementation for the make and clean sticky operations + * should be used by uniprocessor schedulers if SMP support is enabled. * - * @return Always returns false. - */ - bool _Scheduler_default_Ask_for_help( - const Scheduler_Control *scheduler, - Thread_Control *the_thread, - Scheduler_Node *node - ); - - /** - * @brief Does nothing. + * @param scheduler is an unused parameter. * - * @param scheduler This parameter is unused. - * @param the_thread This parameter is unused. - * @param node This parameter is unused. + * @param the_thread is an unused parameter. + * + * @param node is an unused parameter. */ - void _Scheduler_default_Reconsider_help_request( + void _Scheduler_default_Sticky_do_nothing( const Scheduler_Control *scheduler, Thread_Control *the_thread, Scheduler_Node *node @@ -431,44 +492,73 @@ Priority_Control _Scheduler_default_Unmap_priority( /** * @brief Does nothing. * + * This default implementation for the thread pin or unpin operations should + * be used by uniprocessor schedulers if SMP support is enabled. + * * @param scheduler This parameter is unused. - * @param the_thread This parameter is unused.. + * @param the_thread This parameter is unused. * @param node This parameter is unused. - * @param next_state This parameter is unused. + * @param cpu This parameter is unused. */ - void _Scheduler_default_Withdraw_node( + void _Scheduler_default_Pin_or_unpin_do_nothing( const Scheduler_Control *scheduler, Thread_Control *the_thread, Scheduler_Node *node, - Thread_Scheduler_state next_state + struct Per_CPU_Control *cpu ); /** * @brief Does nothing in a single processor system, otherwise a fatal error * is issued. * + * This default implementation for the thread pin or unpin operations should + * be used by SMP schedulers which do not support thread pinning. + * * @param scheduler This parameter is unused. * @param the_thread This parameter is unused. * @param node This parameter is unused. * @param cpu This parameter is unused. */ - void _Scheduler_default_Pin_or_unpin( + void _Scheduler_default_Pin_or_unpin_not_supported( const Scheduler_Control *scheduler, Thread_Control *the_thread, Scheduler_Node *node, struct Per_CPU_Control *cpu ); +#endif - #define SCHEDULER_OPERATION_DEFAULT_ASK_FOR_HELP \ - _Scheduler_default_Ask_for_help, \ - _Scheduler_default_Reconsider_help_request, \ - _Scheduler_default_Withdraw_node, \ - _Scheduler_default_Pin_or_unpin, \ - _Scheduler_default_Pin_or_unpin, \ +/** + * @brief This define provides a set of default implementations for + * SMP-specific scheduler operations. + * + * The default implementations are intended for uniprocessor schedulers. SMP + * schedulers shall implement the operations properly. + * + * If SMP support is disabled, the define evaluates to nothing. + * + * If SMP support is enabled and the system has exactly one processor, then it + * may use an uniprocessor scheduler. The ask for help, reconsider help + * request, and withdraw node operations are NULL, since they are only used if + * a thread has at least one helping scheduler node. At least two schedulers + * are required to get a helping node and each scheduler involved must own at + * least one processor. This is not possible on a system with exactly one + * processor. The processor add operation is NULL, since there is no other + * processor to add. The processor remove operation is NULL, since the one and + * only processor cannot be removed. + */ +#if defined(RTEMS_SMP) + #define SCHEDULER_DEFAULT_SMP_OPERATIONS \ + NULL, \ + NULL, \ + NULL, \ + _Scheduler_default_Sticky_do_nothing, \ + _Scheduler_default_Sticky_do_nothing, \ + _Scheduler_default_Pin_or_unpin_do_nothing, \ + _Scheduler_default_Pin_or_unpin_do_nothing, \ NULL, \ NULL, #else - #define SCHEDULER_OPERATION_DEFAULT_ASK_FOR_HELP + #define SCHEDULER_DEFAULT_SMP_OPERATIONS #endif /** @@ -545,20 +635,6 @@ void _Scheduler_default_Cancel_job( ); /** - * @brief Performs tick operations depending on the CPU budget algorithm for - * each executing thread. - * - * This routine is invoked as part of processing each clock tick. - * - * @param scheduler The scheduler. - * @param[in, out] executing An executing thread. - */ -void _Scheduler_default_Tick( - const Scheduler_Control *scheduler, - Thread_Control *executing -); - -/** * @brief Starts an idle thread. * * @param scheduler This parameter is unused. @@ -594,11 +670,23 @@ void _Scheduler_default_Start_idle( Scheduler_Node *node, const Processor_mask *affinity ); +#endif - #define SCHEDULER_OPERATION_DEFAULT_GET_SET_AFFINITY \ +/** + * @brief This define provides the default implementation for the + * SMP-specific set affinity operation. + * + * The default implementation _Scheduler_default_Set_affinity() is intended for + * uniprocessor schedulers and SMP schedulers which only support an affinity to + * all online processors. + * + * If SMP support is disabled, the define evaluates to nothing. + */ +#if defined(RTEMS_SMP) + #define SCHEDULER_DEFAULT_SET_AFFINITY_OPERATION \ , _Scheduler_default_Set_affinity #else - #define SCHEDULER_OPERATION_DEFAULT_GET_SET_AFFINITY + #define SCHEDULER_DEFAULT_SET_AFFINITY_OPERATION #endif /** |