[1] | 1 | /* |
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| 2 | * scheduler.h - Core scheduler definition. |
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| 3 | * |
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| 4 | * Author Alain Greiner (2016) |
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| 5 | * |
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| 6 | * Copyright (c) UPMC Sorbonne Universites |
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| 7 | * |
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| 8 | * This file is part of ALMOS-MKH. |
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| 9 | * |
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| 10 | * ALMOS-MKH is free software; you can redistribute it and/or modify it |
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| 11 | * under the terms of the GNU General Public License as published by |
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| 12 | * the Free Software Foundation; version 2.0 of the License. |
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| 13 | * |
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| 14 | * ALMOS-MKH is distributed in the hope that it will be useful, but |
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| 15 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 17 | * General Public License for more details. |
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| 18 | * |
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| 19 | * You should have received a copy of the GNU General Public License |
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| 20 | * along with ALMOS-MKH; if not, write to the Free Software Foundation, |
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| 21 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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| 22 | */ |
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| 23 | |
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| 24 | #ifndef _SCHEDULER_H_ |
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| 25 | #define _SCHEDULER_H_ |
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| 26 | |
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| 27 | #include <hal_types.h> |
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| 28 | #include <list.h> |
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| 29 | #include <spinlock.h> |
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| 30 | |
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| 31 | /**** Forward declarations ****/ |
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| 32 | |
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| 33 | struct core_s; |
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| 34 | struct thread_s; |
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| 35 | |
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[279] | 36 | /********************************************************************************************* |
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[1] | 37 | * This structure define the scheduler associated to a given core. |
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[279] | 38 | ********************************************************************************************/ |
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[1] | 39 | |
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| 40 | typedef struct scheduler_s |
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| 41 | { |
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[279] | 42 | spinlock_t lock; /*! readlock protecting lists of threads */ |
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| 43 | uint16_t u_threads_nr; /*! total numbre of attached user threads */ |
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| 44 | uint16_t k_threads_nr; /*! total number of attached kernel threads */ |
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| 45 | list_entry_t u_root; /*! root of list of user threads for this scheduler */ |
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| 46 | list_entry_t k_root; /*! root of list of kernel threads for this scheduler */ |
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| 47 | list_entry_t * u_last; /*! pointer on list_entry for last executed k_thread */ |
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| 48 | list_entry_t * k_last; /*! pointer on list entry for last executed u_thread */ |
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| 49 | struct thread_s * idle; /*! pointer on idle thread */ |
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| 50 | struct thread_s * current; /*! pointer on current running thread */ |
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[409] | 51 | bool_t sig_pending; /*! signal_handller must be called when true */ |
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[1] | 52 | } |
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| 53 | scheduler_t; |
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| 54 | |
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[279] | 55 | /********************************************************************************************* |
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[14] | 56 | * This function initialises the scheduler for a given core. |
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[279] | 57 | ********************************************************************************************/ |
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[1] | 58 | void sched_init( struct core_s * core ); |
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| 59 | |
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[279] | 60 | /********************************************************************************************* |
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[1] | 61 | * This function register a new thread in a given core scheduler. |
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[279] | 62 | ********************************************************************************************* |
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[1] | 63 | * @ core : local pointer on the core descriptor. |
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| 64 | * @ thread : local pointer on the thread descriptor. |
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[279] | 65 | ********************************************************************************************/ |
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[1] | 66 | void sched_register_thread( struct core_s * core, |
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| 67 | struct thread_s * thread ); |
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| 68 | |
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[409] | 69 | /********************************************************************************************* |
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| 70 | * This function remove a thread from its scheduler.re scheduler. |
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[279] | 71 | ********************************************************************************************* |
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[1] | 72 | * @ thread : local pointer on the thread descriptor. |
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[279] | 73 | ********************************************************************************************/ |
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[1] | 74 | void sched_remove_thread( struct thread_s * thread ); |
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| 75 | |
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[279] | 76 | /********************************************************************************************* |
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[408] | 77 | * This function is the only method to make a context switch. It is called in cas of TICK, |
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| 78 | * or when when a thread explicitely requires a scheduling. |
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| 79 | * It handles the pending signals for all threads attached to the core running the calling |
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| 80 | * thread, and calls the sched_select() function to select a new thread. |
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| 81 | * The cause argument is only used for debug by the sched_display() function, and |
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| 82 | * indicates the scheduling cause. |
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| 83 | ********************************************************************************************* |
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| 84 | * @ cause : character string defining the scheduling cause. |
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[279] | 85 | ********************************************************************************************/ |
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[408] | 86 | void sched_yield( char * cause ); |
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[1] | 87 | |
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[279] | 88 | /********************************************************************************************* |
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[1] | 89 | * This function scan all threads attached to a given core scheduler, and executes |
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[409] | 90 | * the relevant actions for pending KILL or EXIT signals. |
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| 91 | * It is called in by the sched_yield() function, with IRQ disabled. |
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[279] | 92 | ********************************************************************************************* |
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[1] | 93 | * @ core : local pointer on the core descriptor. |
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[279] | 94 | ********************************************************************************************/ |
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[1] | 95 | void sched_handle_signals( struct core_s * core ); |
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| 96 | |
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[279] | 97 | /********************************************************************************************* |
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[1] | 98 | * This function does NOT modify the scheduler state. |
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[408] | 99 | * It just select a thread in the list of attached threads, implementing the following |
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| 100 | * three steps policy: |
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| 101 | * 1) It scan the list of kernel threads, from the next thread after the last executed one, |
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| 102 | * and returns the first runnable found : not IDLE, not blocked, client queue not empty. |
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| 103 | * It can be the current thread. |
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| 104 | * 2) If no kernel thread found, it scan the list of user thread, from the next thread after |
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| 105 | * the last executed one, and returns the first runable found : not blocked. |
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| 106 | * It can be the current thread. |
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| 107 | * 3) If no runable thread found, it returns the idle thread. |
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[279] | 108 | ********************************************************************************************* |
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[408] | 109 | * @ core : local pointer on scheduler. |
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[1] | 110 | * @ returns pointer on selected thread descriptor |
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[279] | 111 | ********************************************************************************************/ |
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[408] | 112 | struct thread_s * sched_select( struct scheduler_s * sched ); |
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[1] | 113 | |
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[279] | 114 | /********************************************************************************************* |
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[409] | 115 | * This function unlink a thread identified by the <thread> pointer from its process. |
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| 116 | * It is called by the sched_handle_signals() function when one EXIT or KILL signal is set, |
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| 117 | * and it implement the first step of a thread destructionebut can also be directly called by a local killer thread signal. |
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| 118 | * - It detach the thread from the scheduler. |
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| 119 | * - It detach the thread from the process. |
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| 120 | * - It detach the thread from the parent thread when the thread is attached. |
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| 121 | * - It destroys the thread descriptor. |
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| 122 | * - It acknowledge the killer thread if it's a kill signal |
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| 123 | ********************************************************************************************* |
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| 124 | * @ thread : pointer on thread to be killed. |
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| 125 | ********************************************************************************************/ |
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| 126 | void sched_kill_thread( struct thread_s * thread ); |
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| 127 | |
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| 128 | /********************************************************************************************* |
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[407] | 129 | * This function display the internal state of the local core identified by its <lid>. |
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| 130 | ********************************************************************************************* |
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| 131 | * @ lid : local index of target core. |
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[279] | 132 | ********************************************************************************************/ |
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[407] | 133 | void sched_display( lid_t lid ); |
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[1] | 134 | |
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| 135 | |
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| 136 | #endif /* _SCHEDULER_H_ */ |
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