source: trunk/kernel/kern/scheduler.h @ 401

Last change on this file since 401 was 296, checked in by alain, 7 years ago

Several modifs in the generic scheduler and in the hal_context to
fix the context switch mechanism.

File size: 7.0 KB
RevLine 
[1]1/*
2 * scheduler.h - Core scheduler definition.
3 *
4 * Author    Alain Greiner (2016)
5 *
6 * Copyright (c) UPMC Sorbonne Universites
7 *
8 * This file is part of ALMOS-MKH.
9 *
10 * ALMOS-MKH is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; version 2.0 of the License.
13 *
14 * ALMOS-MKH is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24#ifndef _SCHEDULER_H_
25#define _SCHEDULER_H_
26
27#include <hal_types.h>
28#include <list.h>
29#include <spinlock.h>
30
31/****  Forward declarations  ****/
32
33struct core_s;
34struct thread_s;
35
[279]36/*********************************************************************************************
[1]37 * This structure define the scheduler associated to a given core.
[279]38 ********************************************************************************************/
[1]39
40typedef struct scheduler_s
41{
[279]42    spinlock_t        lock;         /*! readlock protecting lists of threads                */
43    uint16_t          u_threads_nr; /*! total numbre of attached user threads               */
44    uint16_t          k_threads_nr; /*! total number of attached kernel threads             */
45    list_entry_t      u_root;       /*! root of list of user threads for this scheduler     */
46    list_entry_t      k_root;       /*! root of list of kernel threads for this scheduler   */
47    list_entry_t    * u_last;       /*! pointer on list_entry for last executed k_thread    */
48    list_entry_t    * k_last;       /*! pointer on list entry for last executed u_thread    */
49    struct thread_s * idle;         /*! pointer on idle thread                              */
50    struct thread_s * current;      /*! pointer on current running thread                   */
[1]51}
52scheduler_t;
53
[279]54/*********************************************************************************************
[14]55 *  This function initialises the scheduler for a given core.
[279]56 ********************************************************************************************/ 
[1]57void sched_init( struct core_s * core );
58
[279]59/*********************************************************************************************
[1]60 * This function register a new thread in a given core scheduler.
[279]61 *********************************************************************************************
[1]62 * @ core    : local pointer on the core descriptor.
63 * @ thread  : local pointer on the thread descriptor.
[279]64 ********************************************************************************************/ 
[1]65void sched_register_thread( struct core_s   * core,
66                            struct thread_s * thread );
67
[279]68/*********************************************************************************************
[1]69 *  This function removes a thread from the set of threads attached to a given core.
[279]70 *********************************************************************************************
[1]71 * @ thread  : local pointer on the thread descriptor.
[279]72 ********************************************************************************************/ 
[1]73void sched_remove_thread( struct thread_s * thread );
74
[279]75/*********************************************************************************************
[1]76 * This function handles pending signals for all registered threads, and tries to make
77 * a context switch for the core running the calling thread.
[296]78 * - If the <next> argument is not NULL, this next thread starts execution.
79 * - If <next> is NULL, it calls the sched_select() function. If there is a runable thread
80 *   (other than current thread or idle thread), this selected thread starts execution.
[1]81 * - If there is no other runable thread, the calling thread continues execution.
82 * - If there is no runable thread, the idle thread is executed.
[279]83 *********************************************************************************************
[296]84 * @ next  : local pointer on next thread to run / call sched_select() if NULL.
[279]85 ********************************************************************************************/
[296]86void sched_yield( struct thread_s * next );
[1]87
[279]88/*********************************************************************************************
[1]89 * This function scan all threads attached to a given core scheduler, and executes
90 * the relevant actions for pending signals, such as the THREAD_SIG_KILL signal.
[279]91 *********************************************************************************************
[1]92 * @ core    : local pointer on the core descriptor.
[279]93 ********************************************************************************************/
[1]94void sched_handle_signals( struct core_s * core );
95
[279]96/*********************************************************************************************
[1]97 * This function is used by the scheduler of a given core to actually kill a thread that has
98 * the SIG_KILL signal set (following a thread_exit() or a thread_kill() event).
99 * - It checks that the thread has released all locks => panic otherwise...
100 * - It detach the thread from the local process descriptor.
101 * - It removes the thread from the scheduler.
102 * - It release physical memory allocated for thread descriptor.
[279]103 *********************************************************************************************
[1]104 * @ thread  : local pointer on the thread descriptor.
[279]105 ********************************************************************************************/
[1]106void sched_kill_thread( struct thread_s * thread );
107
[279]108/*********************************************************************************************
[1]109 * This function does NOT modify the scheduler state.
110 * It just select a thread in the list of attached threads, implementing the following policy:
111 * 1) it scan the list of kernel threads, from the next thread after the last executed one,
112 *    and returns the first runnable found (can be the current thread).
113 * 2) if no kernel thread found, it scan the list of user thread, from the next thread after
114 *    the last executed one, and returns the first runable found (can be the current thread).
115 * 3) if no runable thread found, it returns the idle thread.
[279]116 *********************************************************************************************
[1]117 * @ core    : local pointer on the core descriptor.
118 * @ returns pointer on selected thread descriptor
[279]119 ********************************************************************************************/
[1]120struct thread_s * sched_select( struct core_s * core );
121
[279]122/*********************************************************************************************
[296]123 * This function display the internal state of the calling core scheduler.
[279]124 ********************************************************************************************/
[296]125void sched_display();
[1]126
127
128#endif  /* _SCHEDULER_H_ */
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