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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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80 | pj | 24 | CVS : $Id: ss.h,v 1.3 2003-03-13 13:39:05 pj Exp $ |
2 | pj | 25 | |
26 | File: $File$ |
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80 | pj | 27 | Revision: $Revision: 1.3 $ |
28 | Last update: $Date: 2003-03-13 13:39:05 $ |
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2 | pj | 29 | ------------ |
30 | |||
31 | This file contains the aperiodic server SS (Sporadic Server) |
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32 | |||
33 | Title: |
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34 | SS (Sporadic Server) |
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35 | |||
36 | Task Models Accepted: |
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37 | SOFT_TASK_MODEL - Soft Tasks |
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38 | wcet field is ignored |
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39 | met field is ignored |
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40 | period field is ignored |
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41 | periodicity field can be only APERIODIC |
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42 | arrivals field can be either SAVE or SKIP |
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43 | |||
44 | Description: |
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45 | This module schedule his tasks following the Sporadic Server scheme. |
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46 | The scheme is slightly modified respect to classic SS. The server |
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47 | becomes active at arrival time of a task must be served. |
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48 | |||
49 | All the tasks are put in a FIFO (FCFS) queue and at a time only the first |
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50 | task in the queue is put in the upper level. |
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51 | |||
52 | The module remembers pending activations when calling task_sleep... |
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53 | |||
54 | Exceptions raised: |
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55 | XUNVALID_GUEST |
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56 | This level doesn't support guests. When a guest operation |
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57 | is called, the exception is raised. |
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58 | XUNVALID_SS_REPLENISH |
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59 | Indicates an anomalous replenishment situation: |
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60 | . replenish time fires and no amounts are set |
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61 | . replenish amount posted when server is not active |
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62 | . no more space to post a replenish amount |
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63 | |||
64 | Restrictions & special features: |
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65 | - This level doesn't manage the main task. |
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66 | - At init time we have to specify: |
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67 | . The Capacity and the period used by the server |
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68 | - The level don't use the priority field. |
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69 | - if an aperiodic task calls a task_delay when owning a mutex implemented |
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70 | with shadows, the delay may have no effect, so don't use delay when |
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71 | using a mutex!!! |
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72 | - On calling task_delay and task_sleep the replenish amount is posted. |
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73 | This because replenish time may fires when task is sleeping (server |
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74 | is not active). |
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75 | - A function to return the used bandwidth of the level is provided. |
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76 | - A function to return the avail server capacity is provided. |
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77 | |||
78 | **/ |
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79 | |||
80 | /* |
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81 | * Copyright (C) 2000 Paolo Gai |
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82 | * |
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83 | * This program is free software; you can redistribute it and/or modify |
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84 | * it under the terms of the GNU General Public License as published by |
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85 | * the Free Software Foundation; either version 2 of the License, or |
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86 | * (at your option) any later version. |
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87 | * |
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88 | * This program is distributed in the hope that it will be useful, |
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89 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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90 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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91 | * GNU General Public License for more details. |
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92 | * |
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93 | * You should have received a copy of the GNU General Public License |
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94 | * along with this program; if not, write to the Free Software |
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95 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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96 | * |
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97 | */ |
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98 | |||
99 | |||
100 | #ifndef __SS_H__ |
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101 | #define __SS_H__ |
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102 | |||
103 | #include <kernel/config.h> |
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104 | #include <kernel/types.h> |
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105 | #include <sys/types.h> |
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80 | pj | 106 | #include "ll/sys/cdefs.h" |
2 | pj | 107 | |
80 | pj | 108 | __BEGIN_DECLS |
109 | |||
2 | pj | 110 | /*+ 1 - ln(2) +*/ |
111 | #ifndef RM_MINFREEBANDWIDTH |
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112 | #define RM_MINFREEBANDWIDTH 1317922825 |
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113 | #endif |
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114 | |||
115 | /*+ Max size of replenish queue +*/ |
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116 | #define SS_MAX_REPLENISH MAX_EVENT |
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117 | |||
118 | /*+ flags... +*/ |
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119 | #define SS_DISABLE_ALL 0 |
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120 | #define SS_ENABLE_BACKGROUND 1 /*+ Background scheduling enabled +*/ |
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121 | #define SS_ENABLE_GUARANTEE_EDF 2 /*+ Task Guarantee enabled +*/ |
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122 | #define SS_ENABLE_ALL_EDF 3 /*+ guarantee+background enabled +*/ |
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123 | |||
124 | #define SS_ENABLE_GUARANTEE_RM 4 /*+ Task Guarantee enabled +*/ |
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125 | #define SS_ENABLE_ALL_RM 5 /*+ guarantee+background enabled +*/ |
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126 | |||
127 | /*+ internal flags +*/ |
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128 | #define SS_BACKGROUND 8 /*+ this flag is set when scheduling |
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129 | in background +*/ |
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130 | #define SS_BACKGROUND_BLOCK 16 /*+ this flag is set when we want to |
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131 | blocks the background scheduling +*/ |
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132 | |||
133 | /*+ internal switches +*/ |
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134 | typedef enum { |
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135 | SS_SERVER_NOTACTIVE, /*+ SS is not active +*/ |
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136 | SS_SERVER_ACTIVE /*+ SS is active +*/ |
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137 | } ss_status; |
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138 | |||
139 | /*+ internal functions +*/ |
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140 | |||
141 | /*+ Used to store replenishment events +*/ |
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142 | /* Now we use static allocated array. In this way, no more then |
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143 | SS_MAX_REPLENISH replenishments can be posted. |
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144 | typedef struct { |
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145 | struct timespec rtime; |
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146 | int ramount; |
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147 | replenishq *next; |
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148 | } replenishq; |
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149 | */ |
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150 | |||
151 | /*+ Registration function: |
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152 | bandwidth_t b Max bandwidth used by the SS |
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153 | int flags Options to be used in this level instance... |
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154 | LEVEL master The level that must be used as master level |
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155 | int Cs Server capacity |
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38 | pj | 156 | int per Server period |
2 | pj | 157 | |
38 | pj | 158 | returns the level number at which the module has been registered. |
159 | +*/ |
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160 | LEVEL SS_register_level(int flags, LEVEL master, int Cs, int per); |
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161 | |||
2 | pj | 162 | /*+ Returns the used bandwidth of a level +*/ |
163 | bandwidth_t SS_usedbandwidth(LEVEL l); |
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164 | |||
165 | /*+ Returns tha available capacity +*/ |
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166 | int SS_availCs(LEVEL l); |
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167 | |||
80 | pj | 168 | __END_DECLS |
2 | pj | 169 | #endif |