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1624 | giacomo | 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 | * (see the web pages for full authors list) |
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11 | * |
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12 | * ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy) |
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13 | * |
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14 | * http://www.sssup.it |
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15 | * http://retis.sssup.it |
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16 | * http://shark.sssup.it |
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17 | */ |
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18 | |||
19 | /* |
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20 | ------------ |
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21 | CVS : $Id: iqueue.h,v 1.1.1.1 2004-05-24 17:54:51 giacomo Exp $ |
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22 | |||
23 | File: $File$ |
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24 | Revision: $Revision: 1.1.1.1 $ |
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25 | Last update: $Date: 2004-05-24 17:54:51 $ |
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26 | ------------ |
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27 | |||
28 | */ |
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29 | |||
30 | /* |
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31 | * Copyright (C) 2002 Paolo Gai |
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32 | * |
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33 | * This program is free software; you can redistribute it and/or modify |
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34 | * it under the terms of the GNU General Public License as published by |
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35 | * the Free Software Foundation; either version 2 of the License, or |
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36 | * (at your option) any later version. |
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37 | * |
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38 | * This program is distributed in the hope that it will be useful, |
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39 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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40 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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41 | * GNU General Public License for more details. |
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42 | * |
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43 | * You should have received a copy of the GNU General Public License |
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44 | * along with this program; if not, write to the Free Software |
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45 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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46 | * |
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47 | */ |
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48 | |||
49 | |||
50 | /* |
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51 | IQUEUEs |
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52 | |||
53 | This file contains functions that helps to manage task queues. |
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54 | |||
55 | These functions are different from the functions that manages the |
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56 | QUEUE and QQUEUE types. In particular, these functions no more relies |
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57 | on the prev & next fields of the task descriptor. In that way, tasks |
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58 | can be inserted in more than one queue at a time. |
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59 | |||
60 | Basically, an IQUEUE has an "I"nternal prev/next structure, that may |
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61 | be shared between one or more queue. Of course, the user MUST |
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62 | guarantee that the same task will not be inserted in two IQUEUEs that |
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63 | share the same prev/next buffer. |
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64 | |||
65 | The queue insertion is made by the following functions: |
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66 | iq_insert -> insertion based on the priority field. |
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67 | iq_timespec_insert -> same as above but use the timespec_priority field |
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68 | iq_insertfirst -> insert in the first position of the queue |
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69 | */ |
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70 | |||
71 | #include <kernel/const.h> |
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72 | #include <kernel/types.h> |
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73 | #include <sys/types.h> |
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74 | |||
75 | #define IQUEUE_NO_PRIORITY 1 |
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76 | #define IQUEUE_NO_TIMESPEC 2 |
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77 | |||
78 | struct IQUEUE_shared { |
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79 | PID prev[MAX_PROC]; |
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80 | PID next[MAX_PROC]; |
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81 | struct timespec *timespec_priority; |
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82 | DWORD *priority; |
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83 | }; |
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84 | |||
85 | typedef struct { |
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86 | PID first; |
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87 | PID last; |
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88 | struct IQUEUE_shared *s; |
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89 | } IQUEUE; |
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90 | |||
91 | |||
92 | |||
93 | /* Internal queue initialization: |
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94 | |||
95 | share = &x -> the internal data structure of the IQUEUE x is used |
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96 | to enqueue the tasks. |
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97 | |||
98 | share = NULL -> an internal data structure to handle prev/next |
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99 | pairs is dynamically allocated (The amount of |
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100 | memory that is allocated can be reduced using the |
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101 | flags). |
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102 | |||
103 | flags can be used to reduce the memory usage of an IQUEUE when share=NULL: |
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104 | IQUEUE_NO_PRIORITY -> the iqueue do not provide internally a priority field |
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105 | IQUEUE_NO_TIMESPEC -> the iqueue do not provide internally a timespec field |
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106 | |||
107 | - note that, if these flags are used, the corresponding insert |
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108 | functions will not work! |
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109 | - the default value for the flags is, of course, 0 |
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110 | */ |
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111 | void iq_init (IQUEUE *q, IQUEUE *share, int flags); |
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112 | |||
113 | /* Queue insert functions: |
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114 | |||
115 | - inserts a p into the q. p must not be already inserted into q. |
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116 | - four versions of the function; |
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117 | - iq_priority_insert -> ordered insertion using the priority field |
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118 | - iq_timespec_insert -> ordered insertion using the timespec field |
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119 | - iq_insertfirst -> insert at the first position of the queue |
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120 | - iq_insertlast -> insert at the last position of the queue |
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121 | */ |
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122 | void iq_priority_insert (PID p, IQUEUE *q); |
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123 | void iq_timespec_insert (PID p, IQUEUE *q); |
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124 | void iq_insertfirst (PID p, IQUEUE *q); |
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125 | void iq_insertlast (PID p, IQUEUE *q); |
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126 | |||
127 | /* Queue extract functions: |
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128 | |||
129 | - extracts a task p from the queue q. |
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130 | - three versions of the function; |
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131 | - iq_extract -> extracts given a task p |
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132 | (that must be inserted in the queue) |
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133 | |||
134 | - iq_getfirst -> extracts the first task in the queue, |
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135 | NIL if the queue is empty |
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136 | |||
137 | - iq_getlast -> extracts the last task in the queue, |
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138 | NIL if the queue is empty |
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139 | |||
140 | */ |
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141 | void iq_extract (PID p, IQUEUE *q); |
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142 | PID iq_getfirst ( IQUEUE *q); |
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143 | PID iq_getlast ( IQUEUE *q); |
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144 | |||
145 | |||
146 | /* Queue query functions: |
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147 | |||
148 | The first two functions return the first and the last task in the queue, |
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149 | NIL if the queue is empty. |
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150 | |||
151 | The second two functions can be used to get/set the priority or the |
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152 | timespec field used when queuing. |
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153 | */ |
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154 | static __inline__ PID iq_queryfirst(IQUEUE *q) |
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155 | { |
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156 | return q->first; |
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157 | } |
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158 | |||
159 | static __inline__ PID iq_querylast(IQUEUE *q) |
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160 | { |
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161 | return q->last; |
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162 | } |
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163 | |||
164 | static __inline__ struct timespec *iq_query_timespec(PID p, IQUEUE *q) |
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165 | { |
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166 | return &q->s->timespec_priority[p]; |
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167 | } |
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168 | |||
169 | static __inline__ DWORD *iq_query_priority (PID p, IQUEUE *q) |
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170 | { |
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171 | return &q->s->priority[p]; |
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172 | } |