/* SPDX-License-Identifier: BSD-2-Clause */
/**
* @file
*
* @ingroup RTEMSScoreThread
*
* @brief This source file contains the definition of
* ::_Thread_CPU_budget_reset_timeslice and the implementation of
* _Thread_CPU_budget_consume_and_yield() and
* _Thread_CPU_budget_set_to_ticks_per_timeslice().
*/
/*
* Copyright (C) 2021 embedded brains GmbH & Co. KG
* Copyright (C) 2010 Gedare Bloom <gedare@rtems.org>
*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/score/threadcpubudget.h>
#include <rtems/score/threadimpl.h>
#include <rtems/score/statesimpl.h>
#include <rtems/score/watchdogticks.h>
void _Thread_CPU_budget_consume_and_yield( Thread_Control *the_thread )
{
uint32_t budget_available;
if ( !the_thread->is_preemptible ) {
return;
}
if ( !_States_Is_ready( the_thread->current_state ) ) {
return;
}
budget_available = the_thread->CPU_budget.available;
if ( budget_available == 1 ) {
the_thread->CPU_budget.available = _Watchdog_Ticks_per_timeslice;
/*
* A yield performs the ready chain mechanics needed when
* resetting a timeslice. If no other thread's are ready
* at the priority of the currently executing thread, then the
* executing thread's timeslice is reset. Otherwise, the
* currently executing thread is placed at the rear of the
* FIFO for this priority and a new heir is selected.
*/
_Thread_Yield( the_thread );
} else {
the_thread->CPU_budget.available = budget_available - 1;
}
}
void _Thread_CPU_budget_set_to_ticks_per_timeslice(
Thread_Control *the_thread
)
{
the_thread->CPU_budget.available = _Watchdog_Ticks_per_timeslice;
}
const Thread_CPU_budget_operations _Thread_CPU_budget_reset_timeslice = {
.at_tick = _Thread_CPU_budget_consume_and_yield,
.at_context_switch = _Thread_CPU_budget_set_to_ticks_per_timeslice,
.initialize = _Thread_CPU_budget_set_to_ticks_per_timeslice
};
