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961 | 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: pi.h,v 1.1 2005-02-25 10:55:09 pj Exp $ |
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25 | |||
26 | File: $File$ |
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27 | Revision: $Revision: 1.1 $ |
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28 | Last update: $Date: 2005-02-25 10:55:09 $ |
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29 | ------------ |
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30 | |||
31 | This file contains the Priority Inheritance (PI) Protocol |
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32 | |||
33 | Title: |
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34 | PI (Priority Inheritance protocol) |
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35 | |||
36 | Resource Models Accepted: |
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37 | None |
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38 | |||
39 | Description: |
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40 | This module implement the Priority Inheritance Protocol. |
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41 | The priority inheritance is made using the shadow field of the |
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42 | task descriptor. No difference is made upon the task model of the |
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43 | tasks that use PI mutexes. |
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44 | |||
45 | A PI mutex is created passing the PI_mutexattr structure to mutex_init. |
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46 | |||
47 | Exceptions raised: |
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48 | XMUTEX_OWNER_KILLED |
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49 | This exception is raised when a task ends and it owns one or more |
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50 | mutexes |
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51 | |||
52 | Restrictions & special features: |
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53 | - This module is NOT Posix compliant |
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54 | - This module can manage any number of PI mutexes. |
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55 | - If a task ends (because it reaches the end of the body or because it |
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56 | is killed by someone) and it owns some mutex, an exception is raised. |
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57 | - if a mutex unlock is called on a mutex not previously |
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58 | locked or previously locked by another task an exception is raised |
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59 | - A PI mutex can be statically allocated. To do this, the init function |
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60 | have to define a macro that puts this information in the mutex |
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61 | descriptor: mutexlevel = <PI resource level>; opt = NULL; |
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62 | for example, if the PI module is registered at level 1, the macro is |
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63 | like: |
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64 | #define MUTEX_INITIALIZER {1,NULL} |
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65 | |||
66 | **/ |
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67 | |||
68 | /* |
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69 | * Copyright (C) 2000 Paolo Gai |
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70 | * |
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71 | * This program is free software; you can redistribute it and/or modify |
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72 | * it under the terms of the GNU General Public License as published by |
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73 | * the Free Software Foundation; either version 2 of the License, or |
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74 | * (at your option) any later version. |
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75 | * |
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76 | * This program is distributed in the hope that it will be useful, |
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77 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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78 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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79 | * GNU General Public License for more details. |
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80 | * |
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81 | * You should have received a copy of the GNU General Public License |
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82 | * along with this program; if not, write to the Free Software |
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83 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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84 | * |
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85 | */ |
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86 | |||
87 | |||
88 | |||
89 | #ifndef __PI_H__ |
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90 | #define __PI_H__ |
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91 | |||
92 | #include <kernel/types.h> |
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1689 | fabio | 93 | #include <arch/sys/cdefs.h> |
961 | pj | 94 | |
95 | __BEGIN_DECLS |
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96 | |||
97 | RLEVEL PI_register_module(void); |
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98 | |||
99 | __END_DECLS |
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100 | #endif |