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2 | pj | 1 | /* |
2 | * Project: S.Ha.R.K. |
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3 | * |
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4 | * Coordinators: |
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5 | * Giorgio Buttazzo <giorgio@sssup.it> |
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6 | * Paolo Gai <pj@gandalf.sssup.it> |
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7 | * |
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8 | * Authors : |
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9 | * Paolo Gai <pj@gandalf.sssup.it> |
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10 | * Massimiliano Giorgi <massy@gandalf.sssup.it> |
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11 | * Luca Abeni <luca@gandalf.sssup.it> |
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12 | * (see the web pages for full authors list) |
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13 | * |
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14 | * ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy) |
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15 | * |
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16 | * http://www.sssup.it |
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17 | * http://retis.sssup.it |
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18 | * http://shark.sssup.it |
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19 | */ |
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20 | |||
21 | |||
22 | /** |
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23 | ------------ |
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24 | CVS : $Id: pc.h,v 1.1.1.1 2002-03-29 14:12:51 pj Exp $ |
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25 | |||
26 | File: $File$ |
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27 | Revision: $Revision: 1.1.1.1 $ |
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28 | Last update: $Date: 2002-03-29 14:12:51 $ |
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29 | ------------ |
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30 | |||
31 | This file contains the Priority Ceiling (PC) Protocol |
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32 | |||
33 | Title: |
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34 | PC (Priority Ceiling protocol) |
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35 | |||
36 | Resource Models Accepted: |
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37 | PC_RES_MODEL |
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38 | This model is used to tell a PC level the priority of a task. |
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39 | |||
40 | Description: |
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41 | This module implement the Priority Ceiling Protocol. |
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42 | The priority inheritance is made using the shadow field of the |
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43 | task descriptor. No difference is made upon the task model of the |
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44 | tasks that use PC mutexes. |
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45 | |||
46 | This module is directly derived from the PI one. |
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47 | |||
48 | A PC mutex is created passing the PC_mutexattr structure to mutex_init. |
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49 | |||
50 | When a task is created, a priority must be assigned to the task. This |
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51 | priority is specified using a PC_RES_MODEL resource model. |
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52 | |||
53 | Exceptions raised: |
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54 | XMUTEX_OWNER_KILLED |
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55 | This exception is raised when a task ends and it owns one or more |
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56 | mutexes |
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57 | |||
58 | Restrictions & special features: |
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59 | - This module is NOT Posix compliant |
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60 | - This module can manage any number of PC mutexes. |
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61 | - If a task ends (because it reaches the end of the body or because it |
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62 | is killed by someone) and it owns some mutex, an exception is raised. |
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63 | - if a mutex unlock is called on a mutex not previously |
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64 | locked or previously locked by another task an exception is raised |
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65 | - A PC mutex can't be statically allocated. |
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66 | |||
67 | **/ |
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68 | |||
69 | /* |
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70 | * Copyright (C) 2000 Paolo Gai |
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71 | * |
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72 | * This program is free software; you can redistribute it and/or modify |
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73 | * it under the terms of the GNU General Public License as published by |
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74 | * the Free Software Foundation; either version 2 of the License, or |
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75 | * (at your option) any later version. |
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76 | * |
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77 | * This program is distributed in the hope that it will be useful, |
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78 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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79 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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80 | * GNU General Public License for more details. |
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81 | * |
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82 | * You should have received a copy of the GNU General Public License |
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83 | * along with this program; if not, write to the Free Software |
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84 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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85 | * |
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86 | */ |
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87 | |||
88 | |||
89 | |||
90 | #ifndef __PC_H__ |
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91 | #define __PC_H__ |
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92 | |||
93 | #include <kernel/types.h> |
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94 | #include <kernel/descr.h> |
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95 | |||
96 | void PC_register_module(void); |
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97 | |||
98 | /*+ This function gets the ceiling of a PC mutex, and it have to be called |
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99 | only by a task that owns the mutex. |
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100 | Returns -1 if the mutex is not a PC mutex, 0 otherwise +*/ |
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101 | int PC_get_mutex_ceiling(const mutex_t *mutex, DWORD *ceiling); |
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102 | |||
103 | /*+ This function sets the ceiling of a PC mutex, and it have to be called |
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104 | only by a task that owns the mutex. |
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105 | Returns -1 if the mutex is not a PC mutex, 0 otherwise +*/ |
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106 | int PC_set_mutex_ceiling(mutex_t *mutex, DWORD ceiling, DWORD *old_ceiling); |
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107 | |||
108 | /*+ This function sets the ceiling of a task +*/ |
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109 | void PC_set_task_ceiling(RLEVEL r, PID p, DWORD priority); |
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110 | |||
111 | #endif |