Navigation
- Accueil
- Présentation :
- FAQ
- Bugs et errata
- Contributions de lecteurs
- Téléchargements
- LXR (référencement des sources)
- Mailing-list
- Liens et Projets reliés
Site hébergé par :
Site hébergé par :
|
[ source navigation ] [ diff markup ] [ identifier search ] [ general search ] |
|||
|
||||
001 /* Copyright (C) 2004 David Decotigny 001 /* Copyright (C) 2004 David Decotigny 002 002 003 This program is free software; you can redi 003 This program is free software; you can redistribute it and/or 004 modify it under the terms of the GNU Genera 004 modify it under the terms of the GNU General Public License 005 as published by the Free Software Foundatio 005 as published by the Free Software Foundation; either version 2 006 of the License, or (at your option) any lat 006 of the License, or (at your option) any later version. 007 007 008 This program is distributed in the hope tha 008 This program is distributed in the hope that it will be useful, 009 but WITHOUT ANY WARRANTY; without even the 009 but WITHOUT ANY WARRANTY; without even the implied warranty of 010 MERCHANTABILITY or FITNESS FOR A PARTICULAR 010 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 011 GNU General Public License for more details 011 GNU General Public License for more details. 012 012 013 You should have received a copy of the GNU 013 You should have received a copy of the GNU General Public License 014 along with this program; if not, write to t 014 along with this program; if not, write to the Free Software 015 Foundation, Inc., 59 Temple Place - Suite 3 015 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 016 USA. 016 USA. 017 */ 017 */ 018 #ifndef _SOS_SCHED_H_ 018 #ifndef _SOS_SCHED_H_ 019 #define _SOS_SCHED_H_ 019 #define _SOS_SCHED_H_ 020 020 021 021 022 /** 022 /** 023 * @file sched.h 023 * @file sched.h 024 * 024 * 025 * A basic scheduler with simple FIFO threads' !! 025 * A basic scheduler inspired from the O(1) Linux scheduler. Supports >> 026 * 2 classes of thread priorities: >> 027 * - so-called 'real-time' threads scheduled according to a simple >> 028 * traditional static priority real-time scheduler. "Real-time" round >> 029 * robin scheduling is not supported. >> 030 * - "fair" time-sharing scheduling for non real-time threads. "fair" >> 031 * because no starvation among the non real-time threads is >> 032 * possible. Contrary to the original O(1) Linux scheduler, the >> 033 * on-line adjustment of the scheduling priorities to cope with >> 034 * interactive/non interactive threads discrimination is not >> 035 * supported: threads keep having the same priority as long as the >> 036 * user does not change it. 026 * 037 * 027 * The functions below manage CPU queues, and 038 * The functions below manage CPU queues, and are NEVER responsible 028 * for context switches (see thread.h for that 039 * for context switches (see thread.h for that) or synchronizations 029 * (see kwaitq.h or the higher levels primitiv 040 * (see kwaitq.h or the higher levels primitives [mutex, semaphore, 030 * ...] for that). 041 * ...] for that). 031 * 042 * 032 * @note IMPORTANT: all the functions below ar 043 * @note IMPORTANT: all the functions below are meant to be called 033 * ONLY by the thread/timer/kwaitq subsystems. 044 * ONLY by the thread/timer/kwaitq subsystems. DO NOT use them 034 * directly from anywhere else: use ONLY the t 045 * directly from anywhere else: use ONLY the thread/kwaitq functions! 035 * If you still want to call them directly des 046 * If you still want to call them directly despite this disclaimer, 036 * simply disable interrupts before clling the 047 * simply disable interrupts before clling them. 037 */ 048 */ 038 049 039 #include <sos/errno.h> 050 #include <sos/errno.h> >> 051 #include <sos/time.h> >> 052 >> 053 >> 054 /** >> 055 * The definition of a priority >> 056 */ >> 057 typedef unsigned char sos_sched_priority_t; 040 058 041 059 042 #include <sos/thread.h> 060 #include <sos/thread.h> 043 061 044 062 045 /** 063 /** >> 064 * Valid priority interval ("real-time" and non real-time threads altogether) >> 065 */ >> 066 #define SOS_SCHED_PRIO_HIGHEST 0 >> 067 #define SOS_SCHED_PRIO_LOWEST 63 >> 068 #define SOS_SCHED_NUM_PRIO 64 >> 069 >> 070 >> 071 /** >> 072 * Class-specific priorities >> 073 */ >> 074 #define SOS_SCHED_PRIO_RT_HIGHEST 0 /**< Highest 'real-time' static prio. */ >> 075 #define SOS_SCHED_PRIO_RT_LOWEST 15 /**< Lowest 'real-time' static priority */ >> 076 #define SOS_SCHED_PRIO_TS_HIGHEST 16 /**< Highest time-sharing priority */ >> 077 #define SOS_SCHED_PRIO_TS_LOWEST 63 /**< Lowest time-sharing priority */ >> 078 >> 079 #define SOS_SCHED_PRIO_DEFAULT 40 /**< Default priority */ >> 080 >> 081 >> 082 /** >> 083 * Helper macros (Yes, priorities ordered in decreasing numerical value) >> 084 * >> 085 * @note: The use of this function is RESERVED >> 086 */ >> 087 #define SOS_SCHED_PRIO_CMP(prio1,prio2) ((prio1) - (prio2)) >> 088 >> 089 #define SOS_SCHED_PRIO_IS_VALID(prio) \ >> 090 ({ int __prio = (int)(prio); \ >> 091 ((__prio) <= SOS_SCHED_PRIO_LOWEST) \ >> 092 && \ >> 093 ((__prio) >= SOS_SCHED_PRIO_HIGHEST); }) >> 094 >> 095 #define SOS_SCHED_PRIO_IS_RT(prio) \ >> 096 ({ int __prio = (int)(prio); \ >> 097 ((__prio) <= SOS_SCHED_PRIO_RT_LOWEST) \ >> 098 && \ >> 099 ((__prio) >= SOS_SCHED_PRIO_RT_HIGHEST); }) >> 100 >> 101 >> 102 /** >> 103 * The time slices for 'time-sharing' user threads, in ms >> 104 */ >> 105 #define SOS_TIME_SLICE_MIN 10 /* for SOS_SCHED_PRIO_TS_HIGHEST */ >> 106 #define SOS_TIME_SLICE_MAX 200 /* for SOS_SCHED_PRIO_TS_LOWEST */ >> 107 >> 108 >> 109 /** 046 * Initialize the scheduler 110 * Initialize the scheduler 047 * 111 * 048 * @note: The use of this function is RESERVED 112 * @note: The use of this function is RESERVED 049 */ 113 */ 050 sos_ret_t sos_sched_subsystem_setup(); 114 sos_ret_t sos_sched_subsystem_setup(); 051 115 052 116 053 /** 117 /** 054 * Mark the given thread as ready 118 * Mark the given thread as ready 055 * 119 * 056 * @note: The use of this function is RESERVED 120 * @note: The use of this function is RESERVED 057 */ 121 */ 058 sos_ret_t sos_sched_set_ready(struct sos_threa 122 sos_ret_t sos_sched_set_ready(struct sos_thread * thr); 059 123 060 124 061 /** 125 /** 062 * Return the identifier of the next thread to 126 * Return the identifier of the next thread to run. Also removes it 063 * from the ready list, but does NOT set is as 127 * from the ready list, but does NOT set is as current_thread ! 064 * 128 * 065 * @param current_thread TCB of the thread cal 129 * @param current_thread TCB of the thread calling the function 066 * 130 * 067 * @param do_yield When TRUE, put the current 131 * @param do_yield When TRUE, put the current executing thread at the 068 * end of the ready list. Otherwise it is kept 132 * end of the ready list. Otherwise it is kept at the head of it. 069 * 133 * 070 * @note: The use of this function is RESERVED 134 * @note: The use of this function is RESERVED 071 */ 135 */ 072 struct sos_thread * sos_reschedule(struct sos_ 136 struct sos_thread * sos_reschedule(struct sos_thread * current_thread, 073 sos_bool_t 137 sos_bool_t do_yield); >> 138 >> 139 /** >> 140 * Called by thread subsystem each time a READY thread's priority is >> 141 * changed >> 142 * >> 143 * @note: The use of this function is RESERVED (to thread.c) >> 144 */ >> 145 sos_ret_t sos_sched_change_priority(struct sos_thread * thr, >> 146 sos_sched_priority_t priority); >> 147 >> 148 >> 149 /** >> 150 * Account for the execution of a time tick. Should be called >> 151 * immediately before the timer ISR calls sos_reschedule() before >> 152 * returning to thread context. >> 153 * >> 154 * @note The use of this function is RESERVED (to timer IRQ) >> 155 */ >> 156 sos_ret_t sos_sched_do_timer_tick(); 074 157 075 #endif /* _SOS_WAITQUEUE_H_ */ 158 #endif /* _SOS_WAITQUEUE_H_ */
| [ source navigation ] | [ diff markup ] | [ identifier search ] | [ general search ] |