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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: pc.h,v 1.1 2005-02-25 10:40:58 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 10:40:58 $ |
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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 | #include "ll/sys/cdefs.h" |
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| 96 | |||
| 97 | __BEGIN_DECLS |
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| 98 | |||
| 99 | RLEVEL PC_register_module(void); |
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| 100 | |||
| 101 | /*+ This function gets the ceiling of a PC mutex, and it have to be called |
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| 102 | only by a task that owns the mutex. |
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| 103 | Returns -1 if the mutex is not a PC mutex, 0 otherwise +*/ |
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| 104 | int PC_get_mutex_ceiling(const mutex_t *mutex, DWORD *ceiling); |
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| 105 | |||
| 106 | /*+ This function sets the ceiling of a PC mutex, and it have to be called |
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| 107 | only by a task that owns the mutex. |
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| 108 | Returns -1 if the mutex is not a PC mutex, 0 otherwise +*/ |
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| 109 | int PC_set_mutex_ceiling(mutex_t *mutex, DWORD ceiling, DWORD *old_ceiling); |
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| 110 | |||
| 111 | /*+ This function sets the ceiling of a task +*/ |
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| 112 | void PC_set_task_ceiling(RLEVEL r, PID p, DWORD priority); |
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| 113 | |||
| 114 | __END_DECLS |
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| 115 | #endif |