source: trunk/kernel/kern/scheduler.h @ 615

Last change on this file since 615 was 564, checked in by alain, 6 years ago

Complete restructuration of kernel locks.

File size: 5.9 KB
RevLine 
[1]1/*
2 * scheduler.h - Core scheduler definition.
3 *
[564]4 * Author    Alain Greiner (2016,2017,2018)
[1]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
[457]27#include <hal_kernel_types.h>
[1]28#include <list.h>
[564]29#include <busylock.h>
[1]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{
[564]42    busylock_t        lock;            /*! lock protecting scheduler state                  */
[416]43    uint16_t          u_threads_nr;    /*! total number 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                     */
46    list_entry_t      k_root;          /*! root of list of kernel threads                   */
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                */
[436]51    volatile bool_t   req_ack_pending; /*! sequencialize ack requests when true             */
[443]52    bool_t            trace;           /*! context switches trace activated if true         */
[1]53}
54scheduler_t;
55
[279]56/*********************************************************************************************
[14]57 *  This function initialises the scheduler for a given core.
[279]58 ********************************************************************************************/ 
[1]59void sched_init( struct core_s * core );
60
[279]61/*********************************************************************************************
[428]62 * This function atomically register a new thread in a given core scheduler.
[564]63 * Note: There is no specific sched_remove_thread(), as a thread is always deleted
64 * by the ched_handle_signals() function, called by the sched_yield() function.
[279]65 *********************************************************************************************
[1]66 * @ core    : local pointer on the core descriptor.
67 * @ thread  : local pointer on the thread descriptor.
[279]68 ********************************************************************************************/ 
[1]69void sched_register_thread( struct core_s   * core,
70                            struct thread_s * thread );
71
[279]72/*********************************************************************************************
[408]73 * This function is the only method to make a context switch. It is called in cas of TICK,
[564]74 * or when a thread explicitely requires to be descheduled.
75 * It takes the scheduler busylock to atomically update the scheduled state.
76 * It calls the sched_select() private function to select a new thread. After switch, it
77 * calls the sched_handle_signals() private function to handle the pending REQ_ACK and
78 * REQ_DELETE flagss for all threads attached to the scheduler: it deletes all threads
79 * marked for delete (and the process descriptor when the deleted thread is the main thread).
80 * As the REQ_DELETE flag can be asynchronously set (between the select and the handle),
81 * the sched_handle-signals() function check that the thread to delete is not the new thread,
82 * because a thread cannot delete itself.
83 * The cause argument is only used for debug by the sched_display() functions, and indicates
84 * the scheduling cause.
[408]85 *********************************************************************************************
86 * @ cause    : character string defining the scheduling cause.
[279]87 ********************************************************************************************/
[470]88void sched_yield( const char * cause );
[1]89
[279]90/*********************************************************************************************
[450]91 * This debug function displays on TXT0 the internal state of a local scheduler,
[564]92 * identified by the core local index <lid>. It must be called by a local thread.
[407]93 *********************************************************************************************
94 * @ lid      : local index of target core.
[279]95 ********************************************************************************************/
[407]96void sched_display( lid_t lid );
[1]97
[450]98/*********************************************************************************************
99 * This debug function displays on TXT0 the internal state of a scheduler,
100 * identified by the target cluster identifier <cxy> and the core local index <lid>.
101 * It can be called by a thread running in any cluster, as it uses remote accesses,
[564]102 * to scan the scheduler lists of threads.
[450]103 *********************************************************************************************
104 * @ cxy      : target cluster identifier
105 * @ lid      : local index of target core.
106 ********************************************************************************************/
107void sched_remote_display( cxy_t  cxy,
108                           lid_t  lid );
[1]109
110#endif  /* _SCHEDULER_H_ */
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