rtems/score/threadcpubudget.h

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup RTEMSScoreThread
0007  *
0008  * @brief This header file provides interfaces used to implement the CPU budget
0009  *   management of threads.
0010  */
0011
0012 /*
0013  * Copyright (C) 2021 embedded brains GmbH & Co. KG
0014  *
0015  * Redistribution and use in source and binary forms, with or without
0016  * modification, are permitted provided that the following conditions
0017  * are met:
0018  * 1. Redistributions of source code must retain the above copyright
0019  *    notice, this list of conditions and the following disclaimer.
0020  * 2. Redistributions in binary form must reproduce the above copyright
0021  *    notice, this list of conditions and the following disclaimer in the
0022  *    documentation and/or other materials provided with the distribution.
0023  *
0024  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0025  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0026  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0027  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0028  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0029  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0030  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0031  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0032  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0033  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0034  * POSSIBILITY OF SUCH DAMAGE.
0035  */
0036
0037 #ifndef _RTEMS_SCORE_THREADCPUBUDGET_H
0038 #define _RTEMS_SCORE_THREADCPUBUDGET_H
0039
0040 #include <rtems/score/thread.h>
0041
0042 #ifdef __cplusplus
0043 extern "C" {
0044 #endif
0045
0046 /**
0047  * @addtogroup RTEMSScoreThread
0048  *
0049  * @{
0050  */
0051
0052 /**
0053  * @brief Does nothing.
0054  *
0055  * @param the_thread is an unused parameter.
0056  */
0057 void _Thread_CPU_budget_do_nothing( Thread_Control *the_thread );
0058
0059 /**
0060  * @brief Sets the available CPU budget of the thread to the configured clock
0061  *   ticks per timeslice.
0062  *
0063  * @param the_thread is the thread to set the available CPU budget.
0064  */
0065 void _Thread_CPU_budget_set_to_ticks_per_timeslice(
0066   Thread_Control *the_thread
0067 );
0068
0069 /**
0070  * @brief Consumes one time quantum of the available CPU budget of the thread
0071  *   and yields the thread if the available CPU budget is fully consumed.
0072  *
0073  * While the thread enabled the non-preemptive mode or is not ready, no time
0074  * quantum is consumed.
0075  *
0076  * @param the_thread is the thread to operate on.
0077  */
0078 void _Thread_CPU_budget_consume_and_yield( Thread_Control *the_thread );
0079
0080 /**
0081  * @brief These CPU budget operations allocate timeslices to the thread.
0082  *
0083  * The timeslice is not reset at a context switch to the thread.  Once a
0084  * timeslice is consumed, the thread yields.
0085  */
0086 extern const Thread_CPU_budget_operations _Thread_CPU_budget_exhaust_timeslice;
0087
0088 /**
0089  * @brief These CPU budget operations allocate timeslices to the thread.
0090  *
0091  * The timeslice is reset at a context switch to the thread.  Once a timeslice
0092  * is consumed, the thread yields.
0093  */
0094 extern const Thread_CPU_budget_operations _Thread_CPU_budget_reset_timeslice;
0095
0096 /** @} */
0097
0098 #ifdef __cplusplus
0099 }
0100 #endif
0101
0102 #endif /* _RTEMS_SCORE_THREADCPUBUDGET_H */