source: trunk/kernel/kern/alarm.c @ 675

Last change on this file since 675 was 669, checked in by alain, 4 years ago

1) Introduce up to 4 command lines arguments in the KSH "load" command.
These arguments are transfered to the user process through the
argc/argv mechanism, using the user space "args" vseg.

2) Introduce the named and anonymous "pipes", for inter-process communication
through the pipe() and mkfifo() syscalls.

3) Introduce the "chat" application to validate the two above mechanisms.

4) Improve printk() and assert() fonctions in printk.c.

File size: 5.3 KB
Line 
1/*
2 * alarm.c - timer based kernel alarm implementation           
3 *
4 * Author     Alain Greiner (2016,2017,2018,2019,2020)
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#include <kernel_config.h>
25#include <hal_kernel_types.h>
26#include <printk.h>
27#include <list.h>
28#include <thread.h>
29#include <core.h>
30#include <alarm.h>
31
32////////////////////////////////////////////////////////////////////////////////////////////
33// This static function registers the alarm identified ny the <new_alarm> argument
34// in the list of alarms rooted in the core identified by the <core> argument.
35// When the existing list of alarms is not empty, it scan the list to insert the new
36// alarm in the right place to respect the absolute dates ordering.
37////////////////////////////////////////////////////////////////////////////////////////////
38// @ new_alarm  : local pointer on the new alarm.
39// @ core       : local pointer on the target core.
40////////////////////////////////////////////////////////////////////////////////////////////
41static void alarm_register( alarm_t * new_alarm,
42                            core_t  * core )
43{
44    list_entry_t * current;          // pointer on current list_entry in existing list
45    list_entry_t * previous;         // pointer on previous list_entry in existing list
46    alarm_t      * current_alarm;    // pointer on current alarm in existing list
47    cycle_t        current_date;     // date of current alarm in existing list
48
49    bool_t         done = false;
50
51    // get pointers on root of alarms and lock
52    list_entry_t * root = &core->alarms_root;
53    busylock_t   * lock = &core->alarms_lock;
54
55    // get pointer on new_alarm list_entry
56    list_entry_t * new_entry = &new_alarm->list;
57
58    // get new_alarm date
59    cycle_t        new_date = new_alarm->date;
60
61    // take the lock
62    busylock_acquire( lock );
63
64    // insert new alarm to respect dates order
65    if( list_is_empty( root ) )                     // list empty
66    {
67        list_add_first( root , new_entry ); 
68    }
69    else                                            // list non empty
70    {
71        for( current = root->next ;
72             (current != root) && (done == false) ;
73             current = current->next )
74        {
75            // get pointer on previous entry in existing list
76            previous = current->pred;
77
78            // get pointer on current alarm
79            current_alarm = LIST_ELEMENT( current , alarm_t , list );
80
81            // get date for current alarm
82            current_date  = current_alarm->date;
83
84            if( current_date > new_date )  // insert new alarm just before current
85            {
86                new_entry->next = current;
87                new_entry->pred = previous;
88
89                current->pred  = new_entry;
90                previous->next = new_entry;
91               
92                done = true;
93            }
94        }  // end for
95       
96        if( done == false ) // new_date is larger than all registered dates
97        {
98            list_add_last( root , new_entry );
99        }
100    }
101
102    // release the lock
103    busylock_release( lock );
104
105}  // end alarm_register()
106
107//////////////////////////////////////
108void alarm_start( cycle_t    date,
109                  void     * func_ptr,
110                  xptr_t     args_xp,
111                  thread_t * thread )
112{
113    // get pointer on alarm
114    alarm_t * alarm = &thread->alarm;
115
116    // initialize alarm descriptor
117    alarm->date     = date;
118    alarm->func_ptr = func_ptr;
119    alarm->args_xp = args_xp;
120   
121    // register alarm in core list
122    alarm_register( alarm , thread->core );
123
124}  // end alarm_start()
125
126/////////////////////////////////////
127void alarm_update( thread_t * thread,
128                   cycle_t    new_date )
129{
130    // get pointer on alarm
131    alarm_t * alarm = &thread->alarm;
132
133    // get pointer on core
134    core_t   * core = thread->core;
135
136    // get pointer on lock protecting the alarms list
137    busylock_t   * lock = &core->alarms_lock;
138
139    // unlink the alarm from the core list
140    busylock_acquire( lock );
141    list_unlink( &alarm->list );
142    busylock_release( lock );
143
144    // update the alarm date
145    alarm->date = new_date;
146
147    // register alarm in core list
148    alarm_register( alarm , core );
149   
150}  // end alarm_update()
151
152////////////////////////////////////
153void alarm_stop( thread_t * thread )
154{
155    // get pointer on alarm
156    alarm_t * alarm = &thread->alarm;
157
158    // get pointer on core
159    core_t * core = thread->core;
160
161    // get pointer on lock protecting the alarms list
162    busylock_t * lock = &core->alarms_lock;
163
164    // unlink the alarm from the list rooted in core
165    busylock_acquire( lock );
166    list_unlink( &alarm->list );
167    busylock_release( lock );
168
169}  // end alarm_stop()
170
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