score/src/schedulercbs.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup RTEMSScoreSchedulerCBS
0007  *
0008  * @brief This source file contains the implementation of
0009  *   _Scheduler_CBS_Budget_callout() and _Scheduler_CBS_Initialize().
0010  */
0011
0012 /*
0013  *  Copyright (C) 2011 Petr Benes.
0014  *  Copyright (C) 2011 On-Line Applications Research Corporation (OAR).
0015  *
0016  * Redistribution and use in source and binary forms, with or without
0017  * modification, are permitted provided that the following conditions
0018  * are met:
0019  * 1. Redistributions of source code must retain the above copyright
0020  *    notice, this list of conditions and the following disclaimer.
0021  * 2. Redistributions in binary form must reproduce the above copyright
0022  *    notice, this list of conditions and the following disclaimer in the
0023  *    documentation and/or other materials provided with the distribution.
0024  *
0025  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0026  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0027  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0028  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0029  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0030  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0031  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0032  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0033  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0034  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0035  * POSSIBILITY OF SUCH DAMAGE.
0036  */
0037
0038 #ifdef HAVE_CONFIG_H
0039 #include "config.h"
0040 #endif
0041
0042 #include <rtems/score/schedulercbsimpl.h>
0043 #include <rtems/score/statesimpl.h>
0044 #include <rtems/score/threadcpubudget.h>
0045
0046 /**
0047  * @brief Invoked when a limited time quantum is exceeded.
0048  *
0049  * This routine is invoked when a limited time quantum is exceeded.
0050  *
0051  * @param the_thread The thread that exceeded a limited time quantum.
0052  */
0053 static void _Scheduler_CBS_Budget_callout( Thread_Control *the_thread )
0054 {
0055   Scheduler_CBS_Node      *node;
0056   Scheduler_CBS_Server_id  server_id;
0057   Thread_queue_Context     queue_context;
0058
0059   node = _Scheduler_CBS_Thread_get_node( the_thread );
0060
0061   /* Put violating task to background until the end of period. */
0062   _Thread_queue_Context_clear_priority_updates( &queue_context );
0063   _Scheduler_CBS_Cancel_job(
0064     NULL,
0065     the_thread,
0066     node->deadline_node,
0067     &queue_context
0068   );
0069   _Thread_Priority_update( &queue_context );
0070
0071   /* Invoke callback function if any. */
0072   if ( node->cbs_server->cbs_budget_overrun ) {
0073     _Scheduler_CBS_Get_server_id(
0074         node->cbs_server->task_id,
0075         &server_id
0076     );
0077     node->cbs_server->cbs_budget_overrun( server_id );
0078   }
0079 }
0080
0081 static void _Scheduler_CBS_Budget_at_tick( Thread_Control *the_thread )
0082 {
0083   uint32_t budget_available;
0084
0085   if ( !the_thread->is_preemptible ) {
0086     return;
0087   }
0088
0089   if ( !_States_Is_ready( the_thread->current_state ) ) {
0090     return;
0091   }
0092
0093   budget_available = the_thread->CPU_budget.available;
0094
0095   if ( budget_available == 1 ) {
0096     the_thread->CPU_budget.available = 0;
0097     _Scheduler_CBS_Budget_callout ( the_thread );
0098   } else {
0099     the_thread->CPU_budget.available = budget_available - 1;
0100   }
0101 }
0102
0103 const Thread_CPU_budget_operations _Scheduler_CBS_Budget = {
0104   .at_tick = _Scheduler_CBS_Budget_at_tick,
0105   .at_context_switch = _Thread_CPU_budget_do_nothing,
0106   .initialize = _Thread_CPU_budget_do_nothing
0107 };
0108
0109 int _Scheduler_CBS_Initialize(void)
0110 {
0111   return SCHEDULER_CBS_OK;
0112 }