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1085 | 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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1123 | pj | 24 | CVS : $Id: slsh.h,v 1.2 2003-01-07 17:10:18 pj Exp $ |
1085 | pj | 25 | |
26 | File: $File$ |
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1123 | pj | 27 | Revision: $Revision: 1.2 $ |
28 | Last update: $Date: 2003-01-07 17:10:18 $ |
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1085 | pj | 29 | ------------ |
30 | Author: Tomas Lennvall, Date: Feb 2000. |
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31 | |||
32 | This file contains the scheduling module for Slot shifting. |
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33 | |||
34 | Title: |
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35 | Slot Shifting |
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36 | |||
37 | Task Models Accepted: |
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38 | STATIC_TASK_MODEL - Periodic Hard tasks that are scheduled by |
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39 | an off-line scheduler, so that all guarantees regarding precedence, mutex |
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40 | deadline violation is taken care of. The tasks are in an executione schedule, |
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41 | that is the order in when they become ready. They have the following fields: |
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42 | est (earliest start time), wcet and absolute deadline. |
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43 | |||
44 | HARD_TASK_MODEL - Hard Tasks (Hard aperiodic requests) |
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45 | wcet field and drel field must be != 0. They are used to set the wcet |
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46 | and deadline of the tasks. |
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47 | periodicity field must be APERIODIC |
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48 | mit field is ignored. |
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49 | |||
50 | SOFT_TASK_MODEL - Soft Tasks (Unspecified tasks) |
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51 | wcet field must be != 0. periodicity filed must be APERIODIC |
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52 | period and met filed is ignored. |
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53 | |||
54 | Guest Models Accepted: |
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55 | NONE - Slot shifting handles all tasks by itself (at this moment). |
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56 | |||
57 | Description: |
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58 | This module schedules the offline scheduled tasks according to the slot- |
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59 | shifting paradigm, dividing time into slots of a fixed length and assigning |
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60 | tasks to execute in those slots. Slot-shifting also keeps track of the free |
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61 | bandwidth in the schedule by using disjoint intervals and sc (spare capacity). |
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62 | Each interval has a sc nr that represents the free bandwidth in that interval, |
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63 | the sc can be used by hard aperiodic tasks, static tasks from later interval or |
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64 | soft aperiodic tasks. Hard aperiodic tasks are guaranteed an incorporated in |
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65 | the schedule by reduction of sc before they execute. No guarantee is |
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66 | performed on the soft aperiodic tasks, they are run when no other task wants |
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67 | to execute and sc is available. |
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68 | |||
69 | Description: |
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70 | This module implements the Slot shifting algorithm, by Gerhard Fohler. Slot shifting |
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71 | schedules off-line scheduled tasks and also handles hard aperiodic requests by the |
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72 | guarantee alorithm. Slot shifting can also handle soft aperiodic tasks, |
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73 | called unspecified. That is tasks without a deadline. |
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74 | |||
75 | Exceptions raised: |
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76 | These exceptions are pclass-dependent... |
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77 | XDEADLINE_MISS |
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78 | If a task miss his deadline, the exception is raised. |
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79 | |||
80 | XWCET_VIOLATION |
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81 | If a task doesn't end the current cycle before if consume the wcet, |
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82 | an exception is raised, and the task is put in the EDF_WCET_VIOLATED |
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83 | state. To reactivate it, use EDF_task_activate via task_activate or |
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84 | manage directly the EDF data structure. Note that the exception is not |
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85 | handled properly, an XDEADLINE_MISS exeeption will also be raised at |
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86 | the period end... |
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87 | |||
88 | Restrictions & special features: |
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89 | - This level doesn't manage the main task. |
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90 | - At init time we can choose if the level have to activate |
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91 | . the wcet check |
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92 | (If a task require more time than declared, it is stopped and put in |
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93 | the state EDF_WCET_VIOLATED; a XWCET_VIOLATION exception is raised) |
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94 | . the task guarantee algorithm |
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95 | (when all task are created the system will check that the task_set |
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96 | will not use more than the available bandwidth) |
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97 | - The level use the priority and timespec_priority fields. |
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98 | - A function to return the used bandwidth of a level is provided. |
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99 | - The guest tasks don't provide the guest_endcycle function |
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100 | |||
101 | **/ |
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102 | |||
103 | /* |
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104 | * Copyright (C) 2000 Paolo Gai |
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105 | * |
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106 | * This program is free software; you can redistribute it and/or modify |
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107 | * it under the terms of the GNU General Public License as published by |
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108 | * the Free Software Foundation; either version 2 of the License, or |
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109 | * (at your option) any later version. |
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110 | * |
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111 | * This program is distributed in the hope that it will be useful, |
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112 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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113 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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114 | * GNU General Public License for more details. |
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115 | * |
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116 | * You should have received a copy of the GNU General Public License |
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117 | * along with this program; if not, write to the Free Software |
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118 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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119 | * |
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120 | */ |
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121 | |||
122 | |||
123 | #ifndef __SLSH_H__ |
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124 | #define __SLSH_H__ |
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125 | |||
126 | #include <ll/ll.h> |
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127 | #include <kernel/config.h> |
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128 | #include <sys/types.h> |
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129 | #include <kernel/types.h> |
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130 | |||
131 | #define STATIC_PCLASS 0x0500 |
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132 | |||
133 | #define SLSH_LEVELNAME "Slot Shifting" |
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134 | #define SLSH_LEVEL_CODE 5 |
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135 | #define SLSH_LEVEL_VERSION 1 |
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136 | |||
137 | |||
138 | |||
139 | /* ----------------------------------------------------------------------- |
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140 | STATIC_TASK_MODEL: offline scheduled Tasks |
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141 | ----------------------------------------------------------------------- */ |
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142 | /* Offline-scheduled tasks are hard periodic tasks that have been |
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143 | scheduled before runtime. All guarantees are made by the off- |
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144 | line scheduler so the tasks are already guaranteed. |
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145 | */ |
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146 | |||
147 | typedef struct { |
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148 | TASK_MODEL t; |
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149 | TIME est; |
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150 | TIME wcet; |
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151 | TIME dabs; |
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152 | int interval; /* used in slot shifting */ |
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153 | } STATIC_TASK_MODEL; |
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154 | |||
155 | #define static_task_default_model(m) \ |
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156 | task_default_model((m).t,STATIC_PCLASS), \ |
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157 | (m).est = -1, \ |
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158 | (m).dabs = 0, \ |
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159 | (m).wcet = 0, \ |
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160 | (m).interval = -1; |
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161 | #define static_task_def_level(m,l) task_def_level((m).t,l) |
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162 | #define static_task_def_arg(m,a) task_def_arg((m).t,a) |
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163 | #define static_task_def_stack(m,s) task_def_stack((m).t,s) |
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164 | #define static_task_def_group(m,g) task_def_group((m).t,g) |
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165 | #define static_task_def_usemath(m) task_def_usemath((m).t) |
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166 | #define static_task_def_system(m) task_def_system((m).t) |
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167 | #define static_task_def_nokill(m) task_def_nokill((m).t) |
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168 | #define static_task_def_ctrl_jet(m) task_def_ctrl_jet((m).t) |
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169 | #define static_task_def_est(m,p) (m).est = (p) |
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170 | #define static_task_def_dabs(m,d) (m).dabs = (d) |
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171 | #define static_task_def_wcet(m,w) (m).wcet = (w) |
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172 | #define static_task_def_interval(m,i) (m).interval = (i) |
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173 | #define static_task_def_trace(m) task_def_trace((m).t) |
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174 | #define static_task_def_notrace(m) task_def_notrace((m).t) |
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175 | |||
176 | |||
177 | |||
178 | |||
179 | /*#define min(a, b) ((a) < (b) ? (a) : (b))*/ |
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180 | |||
181 | #define TIME2TIMESPEC(T, TS) \ |
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182 | ( \ |
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183 | ((TS).tv_sec = ((T)/1000000)), \ |
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184 | ((TS).tv_nsec = (((T)%1000000) * 1000)), \ |
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185 | (TS) \ |
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186 | ) |
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187 | |||
188 | /* define the interval struct */ |
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189 | typedef struct { |
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190 | int start; /* start of interval */ |
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191 | int end; /* end of interval */ |
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192 | int length; /* Length of interval */ |
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193 | int maxt; /* maximum execution time in interval */ |
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194 | int sc; /* spare capacity in interval */ |
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195 | } SLSH_interval; |
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196 | |||
197 | /*+ Registration function: */ |
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1123 | pj | 198 | LEVEL SLSH_register_level(); |
1085 | pj | 199 | |
200 | void SLSH_set_interval(LEVEL l, int start, int end, int maxt); |
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201 | void SLSH_set_variables(LEVEL l, TIME length); |
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202 | |||
203 | #endif |
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204 |