125 lines
3.7 KiB
C
125 lines
3.7 KiB
C
/*
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ChibiOS/RT - Copyright (C) 2006-2007 Giovanni Di Sirio.
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This file is part of ChibiOS/RT.
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ChibiOS/RT is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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ChibiOS/RT is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/**
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* @file scheduler.h
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* @brief Scheduler macros and structures.
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* @addtogroup scheduler
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* @{
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*/
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#ifndef _SCHEDULER_H_
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#define _SCHEDULER_H_
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/** Default thread wakeup low level message. */
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#define RDY_OK 0
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/** Low level message sent to a thread awakened by a timeout. */
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#define RDY_TIMEOUT -1
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/** Low level message sent to a thread awakened by a reset operation. */
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#define RDY_RESET -2
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#define NOPRIO 0 /**< Ready list header priority.*/
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#define IDLEPRIO 1 /**< Idle thread priority.*/
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#define LOWPRIO 2 /**< Lowest user priority.*/
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#define NORMALPRIO 64 /**< Normal user priority.*/
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#define HIGHPRIO 127 /**< Highest user priority.*/
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#define ABSPRIO 255 /**< Greatest possible priority.*/
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/**
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* Zero time specification for some syscalls with a timeout
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* specification.
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* @note Not all functions accept @p TIME_IMMEDIATE as timeout parameter,
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* see the specific function documentation.
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*/
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#define TIME_IMMEDIATE ((systime_t)-1)
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/**
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* Infinite time specification for all the syscalls with a timeout
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* specification.
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*/
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#define TIME_INFINITE ((systime_t)0)
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/** The priority of the first thread on the given ready list. */
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#define firstprio(rlp) ((rlp)->p_next->p_prio)
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/**
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* @brief Ready list header.
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*
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* @extends ThreadsQueue
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*/
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typedef struct {
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ThreadsQueue r_queue; /**< Threads queue.*/
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tprio_t r_prio; /**< This field must be initialized to
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zero.*/
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/* End of the fields shared with the Thread structure.*/
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#if CH_USE_ROUNDROBIN
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cnt_t r_preempt; /**< Round robin counter.*/
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#endif
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#ifndef CH_CURRP_REGISTER_CACHE
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Thread *r_current; /**< The currently running thread.*/
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#endif
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} ReadyList;
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extern ReadyList rlist;
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#ifdef CH_CURRP_REGISTER_CACHE
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register Thread *currp asm(CH_CURRP_REGISTER_CACHE);
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#else
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#define currp rlist.r_current
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#endif
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/*
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* Scheduler APIs.
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*/
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#ifdef __cplusplus
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extern "C" {
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#endif
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void scheduler_init(void);
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Thread *chSchReadyI(Thread *tp);
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void chSchGoSleepS(tstate_t newstate);
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msg_t chSchGoSleepTimeoutS(tstate_t newstate, systime_t time);
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void chSchWakeupS(Thread *tp, msg_t msg);
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void chSchDoRescheduleI(void);
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void chSchRescheduleS(void);
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bool_t chSchIsRescRequiredExI(void);
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#if CH_USE_ROUNDROBIN
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void chSchDoYieldS(void);
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#endif
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#ifdef __cplusplus
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}
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#endif
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/**
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* @brief Determines if yielding is possible.
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* @details This function returns @p TRUE if there is a ready thread with
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* equal or higher priority.
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*/
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#define chSchCanYieldS() (firstprio(&rlist.r_queue) >= currp->p_prio)
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/**
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* @brief Determines if the current thread must reschedule.
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* @details This function returns @p TRUE if there is a ready thread with
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* higher priority.
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*/
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#define chSchIsRescRequiredI() (firstprio(&rlist.r_queue) > currp->p_prio)
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#endif /* _SCHEDULER_H_ */
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/** @} */
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