root / trunk / code / projects / libwireless / lib / wl_token_ring.c @ 198
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1 | 17 | bcoltin | #include <wl_token_ring.h> |
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2 | |||
3 | #include <stdlib.h> |
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4 | #include <stdio.h> |
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5 | |||
6 | #include <wl_defs.h> |
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7 | #include <wireless.h> |
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8 | #include <sensor_matrix.h> |
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9 | |||
10 | #ifdef ROBOT
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11 | 86 | bcoltin | #ifndef FIREFLY
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12 | 17 | bcoltin | #include <bom.h> |
13 | 86 | bcoltin | #endif
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14 | 17 | bcoltin | #include <time.h> |
15 | #endif
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16 | |||
17 | #define DEFAULT_SENSOR_MATRIX_SIZE 20 |
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18 | |||
19 | /*Ring States*/
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20 | |||
21 | #define NONMEMBER 0 |
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22 | #define MEMBER 1 |
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23 | #define JOINING 2 |
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24 | #define ACCEPTED 3 |
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25 | #define LEAVING 4 |
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26 | |||
27 | /*Frame Types*/
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28 | #define TOKEN_JOIN_ACCEPT_FRAME 1 |
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29 | |||
30 | /*Function Prototypes*/
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31 | |||
32 | /*Wireless Library Prototypes*/
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33 | void wl_token_ring_timeout_handler(void); |
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34 | void wl_token_ring_response_handler(int frame, int received); |
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35 | void wl_token_ring_receive_handler(char type, int source, unsigned char* packet, |
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36 | int length);
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37 | void wl_token_ring_cleanup(void); |
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38 | |||
39 | /*Helper Functions*/
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40 | void wl_token_pass_token(void); |
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41 | int get_token_distance(int robot1, int robot2); |
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42 | void wl_token_get_token(void); |
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43 | |||
44 | /*Packet Handling Routines*/
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45 | void wl_token_pass_receive(int source, char nextRobot, unsigned char* sensorData, int sensorDataLength); |
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46 | void wl_token_bom_on_receive(int source); |
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47 | void wl_token_join_receive(int source); |
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48 | void wl_token_join_accept_receive(int source); |
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49 | |||
50 | /*Global Variables*/
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51 | |||
52 | //the sensor matrix
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53 | SensorMatrix* sensorMatrix; |
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54 | |||
55 | //the robot we are waiting to say it has received the token. -1 if unspecified
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56 | int wl_token_next_robot = -1; |
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57 | |||
58 | //true if the robot should be in the token ring, 0 otherwise
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59 | int ringState = NONMEMBER;
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60 | //the id of the robot who accepted us into the token ring, only used in ACCEPTED state
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61 | int acceptor = -1; |
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62 | //id of the robot we are accepting
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63 | int accepted = -1; |
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64 | |||
65 | //the counter for when we assume a robot is dead
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66 | int deathDelay = -1; |
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67 | //the counter for joining, before we form our own token ring
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68 | int joinDelay = -1; |
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69 | |||
70 | 52 | bcoltin | //current robot to check in the iterator
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71 | int iteratorCount = 0; |
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72 | |||
73 | 196 | bcoltin | // the amount of time a robot has had its BOM on for
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74 | int bom_on_count = 0; |
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75 | |||
76 | 86 | bcoltin | void do_nothing(void) {} |
77 | int get_nothing(void) {return -1;} |
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78 | |||
79 | 17 | bcoltin | #ifdef ROBOT
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80 | 86 | bcoltin | #ifndef FIREFLY
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81 | 17 | bcoltin | void (*bom_on_function) (void) = bom_on; |
82 | void (*bom_off_function) (void) = bom_off; |
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83 | int (*get_max_bom_function) (void) = get_max_bom; |
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84 | #else
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85 | void (*bom_on_function) (void) = do_nothing; |
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86 | void (*bom_off_function) (void) = do_nothing; |
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87 | int (*get_max_bom_function) (void) = get_nothing; |
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88 | #endif
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89 | 86 | bcoltin | #else
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90 | void (*bom_on_function) (void) = do_nothing; |
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91 | void (*bom_off_function) (void) = do_nothing; |
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92 | int (*get_max_bom_function) (void) = get_nothing; |
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93 | #endif
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94 | 17 | bcoltin | |
95 | PacketGroupHandler wl_token_ring_handler = |
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96 | {WL_TOKEN_RING_GROUP, wl_token_ring_timeout_handler, |
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97 | wl_token_ring_response_handler, wl_token_ring_receive_handler, |
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98 | wl_token_ring_cleanup}; |
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99 | |||
100 | /**
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101 | * Initialize the token ring packet group and register it with the
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102 | * wireless library. The robot will not join a token ring.
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103 | **/
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104 | void wl_token_ring_register()
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105 | { |
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106 | if (wl_get_xbee_id() > 0xFF) |
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107 | { |
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108 | //Note: if this becomes an issue (unlikely), we could limit sensor information
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109 | //to half a byte and use 12 bits for the id
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110 | WL_DEBUG_PRINT("XBee ID must be single byte for token ring, is ");
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111 | WL_DEBUG_PRINT_INT(wl_get_xbee_id()); |
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112 | WL_DEBUG_PRINT(".\r\n");
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113 | return;
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114 | } |
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115 | |||
116 | sensorMatrix = sensor_matrix_create(); |
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117 | //add ourselves to the sensor matrix
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118 | sensor_matrix_set_in_ring(sensorMatrix, wl_get_xbee_id(), 0);
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119 | |||
120 | wl_register_packet_group(&wl_token_ring_handler); |
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121 | } |
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122 | |||
123 | /**
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124 | * Removes the packet group from the wireless library.
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125 | **/
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126 | void wl_token_ring_unregister()
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127 | { |
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128 | wl_unregister_packet_group(&wl_token_ring_handler); |
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129 | } |
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130 | |||
131 | /**
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132 | * Sets the functions that are called when the BOM ought to be
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133 | * turned on or off. This could be used for things such as
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134 | * charging stations, which have multiple BOMs.
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135 | *
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136 | * @param on_function the function to be called when the BOM
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137 | * should be turned on
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138 | * @param off_function the function to be called when the BOM
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139 | * should be turned off
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140 | * @param max_bom_function the function to be called when a
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141 | * measurement of the maximum BOM reading is needed.
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142 | **/
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143 | void wl_token_ring_set_bom_functions(void (*on_function) (void), |
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144 | void (*off_function) (void), int (*max_bom_function) (void)) |
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145 | { |
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146 | bom_on_function = on_function; |
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147 | bom_off_function = off_function; |
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148 | get_max_bom_function = max_bom_function; |
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149 | } |
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150 | |||
151 | /**
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152 | * Called to cleanup the token ring packet group.
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153 | **/
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154 | void wl_token_ring_cleanup()
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155 | { |
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156 | sensor_matrix_destroy(sensorMatrix); |
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157 | } |
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158 | |||
159 | /**
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160 | * Called approximately every quarter second by the wireless library.
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161 | **/
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162 | void wl_token_ring_timeout_handler()
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163 | { |
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164 | //someone is not responding, assume they are dead
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165 | if (deathDelay == 0) |
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166 | { |
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167 | //pass the token to the next robot if we think someone has died
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168 | //also, declare that person dead, as long as it isn't us
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169 | if (wl_token_next_robot != wl_get_xbee_id())
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170 | { |
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171 | sensor_matrix_set_in_ring(sensorMatrix, wl_token_next_robot, 0);
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172 | WL_DEBUG_PRINT("Robot ");
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173 | WL_DEBUG_PRINT_INT(wl_token_next_robot); |
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174 | WL_DEBUG_PRINT(" has died.\r\n");
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175 | 183 | bcoltin | wl_token_next_robot = -1;
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176 | deathDelay = DEATH_DELAY; |
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177 | 17 | bcoltin | } |
178 | 43 | bcoltin | |
179 | // we may have been dropped from the ring when this is received
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180 | if (ringState == MEMBER)
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181 | wl_token_pass_token(); |
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182 | 17 | bcoltin | } |
183 | |||
184 | //we must start our own token ring, no one is responding to us
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185 | if (joinDelay == 0) |
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186 | { |
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187 | if (sensor_matrix_get_joined(sensorMatrix) == 0) |
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188 | { |
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189 | WL_DEBUG_PRINT("Creating our own token ring, no robots seem to exist.\r\n");
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190 | sensor_matrix_set_in_ring(sensorMatrix, wl_get_xbee_id(), 1);
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191 | ringState = MEMBER; |
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192 | //this will make us pass the token to ourself
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193 | //repeatedly, and other robots when they join
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194 | deathDelay = DEATH_DELAY; |
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195 | wl_token_next_robot = wl_get_xbee_id(); |
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196 | } |
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197 | else
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198 | { |
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199 | WL_DEBUG_PRINT("Attempting to join the token ring again.\r\n");
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200 | //attempt to rejoin with a random delay
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201 | wl_token_ring_join(); |
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202 | joinDelay = rand() / (RAND_MAX / JOIN_DELAY) + 1;
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203 | } |
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204 | } |
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205 | |||
206 | if (deathDelay >= 0) |
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207 | deathDelay--; |
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208 | if (joinDelay >= 0) |
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209 | joinDelay--; |
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210 | 196 | bcoltin | if (bom_on_count >= 0) |
211 | bom_on_count++; |
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212 | 17 | bcoltin | } |
213 | |||
214 | /**
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215 | * Called when the XBee tells us if a packet we sent has been received.
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216 | *
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217 | * @param frame the frame number assigned when the packet was sent
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218 | * @param received 1 if the packet was received, 0 otherwise
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219 | **/
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220 | void wl_token_ring_response_handler(int frame, int received) |
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221 | { |
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222 | if (!received)
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223 | { |
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224 | WL_DEBUG_PRINT("FAILED.\r\n");
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225 | } |
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226 | } |
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227 | |||
228 | /**
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229 | * Called when we recieve a token ring packet.
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230 | * @param type the type of the packet
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231 | * @param source the id of the robot who sent the packet
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232 | * @param packet the data in the packet
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233 | * @param length the length of the packet in bytes
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234 | **/
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235 | void wl_token_ring_receive_handler(char type, int source, unsigned char* packet, |
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236 | int length)
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237 | { |
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238 | switch (type)
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239 | { |
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240 | case WL_TOKEN_PASS:
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241 | if (length < 1) |
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242 | { |
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243 | WL_DEBUG_PRINT("Malformed Token Pass packet received.\r\n");
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244 | return;
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245 | } |
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246 | wl_token_pass_receive(source, packet[0], packet + 1, length - 1); |
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247 | break;
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248 | case WL_TOKEN_BOM_ON:
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249 | //add the robot to the sensor matrix if it is not already there
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250 | wl_token_bom_on_receive(source); |
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251 | break;
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252 | case WL_TOKEN_JOIN:
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253 | wl_token_join_receive(source); |
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254 | break;
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255 | case WL_TOKEN_JOIN_ACCEPT:
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256 | wl_token_join_accept_receive(source); |
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257 | break;
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258 | default:
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259 | WL_DEBUG_PRINT("Unimplemented token ring packet received.\r\n");
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260 | break;
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261 | } |
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262 | } |
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263 | |||
264 | /**
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265 | * Causes the robot to join an existing token ring, or create one
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266 | * if no token ring exists. The token ring uses global and robot to robot
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267 | * packets, and does not rely on any PAN.
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268 | **/
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269 | void wl_token_ring_join()
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270 | { |
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271 | WL_DEBUG_PRINT("Joining the token ring.\r\n");
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272 | ringState = JOINING; |
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273 | 190 | bcoltin | joinDelay = DEATH_DELAY * 2;
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274 | 17 | bcoltin | wl_send_global_packet(WL_TOKEN_RING_GROUP, WL_TOKEN_JOIN, |
275 | NULL, 0, 0); |
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276 | } |
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277 | |||
278 | /**
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279 | * Causes the robot to leave the token ring. The robot stops
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280 | * alerting others of its location, but continues storing the
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281 | * locations of other robots.
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282 | **/
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283 | void wl_token_ring_leave()
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284 | { |
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285 | ringState = LEAVING; |
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286 | } |
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287 | |||
288 | /**
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289 | * Returns the BOM reading robot source has for robot dest.
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290 | *
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291 | * @param source the robot that made the BOM reading
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292 | * @param dest the robot whose relative location is returned
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293 | *
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294 | * @return a BOM reading from robot source to robot dest,
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295 | * in the range 0-15, or -1 if it is unknown
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296 | **/
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297 | int wl_token_get_sensor_reading(int source, int dest) |
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298 | { |
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299 | return sensor_matrix_get_reading(sensorMatrix, source, dest);
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300 | } |
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301 | |||
302 | /**
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303 | * Returns the BOM reading we have for robot dest.
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304 | *
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305 | * @param dest the robot whose relative location is returned
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306 | *
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307 | * @return a BOM reading from us to robot dest, in the range
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308 | * 0-15, or -1 if it is unkown
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309 | **/
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310 | int wl_token_get_my_sensor_reading(int dest) |
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311 | { |
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312 | return wl_token_get_sensor_reading(wl_get_xbee_id(), dest);
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313 | } |
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314 | |||
315 | /**
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316 | * This method is called when we receive a token pass packet.
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317 | * @param source is the robot it came from
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318 | * @param nextRobot is the robot the token was passed to
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319 | * @param sensorData a char with an id followed by a char with the sensor
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320 | * reading for that robot, repeated for sensorDataLength bytes
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321 | * @param sensorDataLength the length in bytes of sensorData
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322 | */
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323 | void wl_token_pass_receive(int source, char nextRobot, unsigned char* sensorData, int sensorDataLength) |
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324 | { |
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325 | int i, j;
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326 | 196 | bcoltin | |
327 | 198 | bcoltin | // this prevents two tokens from being passed around at a time (second clause is in case we are joining)
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328 | if (source != wl_token_next_robot && bom_on_count <= DEATH_DELAY / 2 && |
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329 | ringState != ACCEPTED) |
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330 | 196 | bcoltin | { |
331 | WL_DEBUG_PRINT("Received token pass when a robot should not have died yet.\n");
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332 | WL_DEBUG_PRINT("There are probably two tokens going around, packet ignored.\n");
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333 | return;
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334 | } |
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335 | |||
336 | bom_on_count = -1;
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337 | 17 | bcoltin | deathDelay = -1;
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338 | 138 | bcoltin | WL_DEBUG_PRINT("Received the token from robot");
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339 | WL_DEBUG_PRINT_INT(source); |
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340 | WL_DEBUG_PRINT(", next robot is ");
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341 | 17 | bcoltin | WL_DEBUG_PRINT_INT((int)nextRobot);
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342 | WL_DEBUG_PRINT(" \r\n");
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343 | sensor_matrix_set_in_ring(sensorMatrix, source, 1);
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344 | |||
345 | //with this packet, we are passed the id of the next robot in the ring
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346 | //and the sensor matrix, a list of id and sensor reading pairs (two bytes for both)
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347 | j = 0;
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348 | for (i = 0; i < sensor_matrix_get_size(sensorMatrix); i++) |
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349 | { |
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350 | if (i == source)
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351 | continue;
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352 | |||
353 | //set the sensor information we receive
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354 | if (j < sensorDataLength / 2 && sensorData[2 * j] == i) |
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355 | { |
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356 | //the robot we were going to accept has already been accepted
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357 | if (accepted == i)
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358 | { |
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359 | accepted = -1;
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360 | WL_DEBUG_PRINT("Someone accepted the robot we did.\r\n");
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361 | } |
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362 | sensor_matrix_set_reading(sensorMatrix, source, i, |
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363 | sensorData[2 * j + 1]); |
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364 | sensor_matrix_set_in_ring(sensorMatrix, i, 1);
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365 | j++; |
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366 | } |
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367 | else
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368 | { |
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369 | if (sensor_matrix_get_in_ring(sensorMatrix, i))
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370 | { |
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371 | WL_DEBUG_PRINT("Robot ");
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372 | WL_DEBUG_PRINT_INT(i); |
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373 | WL_DEBUG_PRINT(" has been removed from the sensor matrix of robot ");
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374 | WL_DEBUG_PRINT_INT(wl_get_xbee_id()); |
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375 | WL_DEBUG_PRINT(" due to a packet from robot ");
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376 | WL_DEBUG_PRINT_INT(source); |
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377 | WL_DEBUG_PRINT(".\r\n");
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378 | sensor_matrix_set_in_ring(sensorMatrix, i, 0);
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379 | } |
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380 | |||
381 | if (i == wl_get_xbee_id() && ringState == MEMBER)
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382 | { |
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383 | ringState = NONMEMBER; |
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384 | wl_token_ring_join(); |
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385 | |||
386 | WL_DEBUG_PRINT("We have been removed from the ring ");
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387 | WL_DEBUG_PRINT("and are rejoining.\r\n");
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388 | } |
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389 | |||
390 | //the person who accepted us is dead... let's ask again
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391 | if (i == acceptor)
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392 | { |
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393 | sensor_matrix_set_in_ring(sensorMatrix, |
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394 | wl_get_xbee_id(), 1);
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395 | ringState = NONMEMBER; |
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396 | acceptor = -1;
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397 | wl_token_ring_join(); |
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398 | } |
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399 | } |
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400 | } |
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401 | |||
402 | wl_token_next_robot = nextRobot; |
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403 | |||
404 | deathDelay = get_token_distance(wl_get_xbee_id(), nextRobot) * DEATH_DELAY; |
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405 | |||
406 | //we have the token
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407 | if (wl_token_next_robot == wl_get_xbee_id())
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408 | wl_token_get_token(); |
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409 | } |
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410 | |||
411 | /**
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412 | * Gets the distance in the token ring between two robots.
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413 | *
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414 | * @param robot1 the first robot
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415 | * @param robot2 the second robot
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416 | *
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417 | * @return the number of passes before the token is expected
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418 | * to reach robot2 from robot1
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419 | **/
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420 | int get_token_distance(int robot1, int robot2) |
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421 | { |
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422 | int curr = robot1 + 1; |
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423 | int count = 1; |
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424 | while (1) |
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425 | { |
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426 | if (curr == sensor_matrix_get_size(sensorMatrix))
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427 | curr = 0;
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428 | if (curr == robot2)
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429 | break;
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430 | if (sensor_matrix_get_in_ring(sensorMatrix, curr))
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431 | count++; |
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432 | curr++; |
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433 | } |
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434 | return count;
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435 | } |
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436 | |||
437 | /**
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438 | * Passes the token to the next robot in the token ring.
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439 | **/
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440 | void wl_token_pass_token()
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441 | { |
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442 | char nextRobot;
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443 | int i = wl_get_xbee_id() + 1; |
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444 | if (accepted == -1) |
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445 | { |
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446 | while (1) |
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447 | { |
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448 | if (i == sensor_matrix_get_size(sensorMatrix))
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449 | i = 0;
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450 | if (sensor_matrix_get_in_ring(sensorMatrix, i))
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451 | { |
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452 | nextRobot = (char)i;
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453 | break;
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454 | } |
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455 | i++; |
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456 | } |
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457 | } |
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458 | else
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459 | { |
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460 | WL_DEBUG_PRINT("Accepting new robot, sending it the token.\r\n");
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461 | //add a new robot to the token ring
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462 | sensor_matrix_set_in_ring(sensorMatrix, accepted, 1);
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463 | nextRobot = accepted; |
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464 | accepted = -1;
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465 | } |
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466 | |||
467 | //we don't include ourself
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468 | int packetSize = 1 + 2 * (sensor_matrix_get_joined(sensorMatrix) - 1); |
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469 | char* buf = (char*)malloc(packetSize * sizeof(char)); |
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470 | if (!buf)
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471 | { |
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472 | WL_DEBUG_PRINT_INT(packetSize); |
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473 | WL_DEBUG_PRINT("Out of memory - pass token.\r\n");
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474 | return;
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475 | } |
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476 | buf[0] = nextRobot;
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477 | |||
478 | int j = 0; |
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479 | for (i = 0; i < sensor_matrix_get_size(sensorMatrix); i++) |
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480 | if (sensor_matrix_get_in_ring(sensorMatrix, i) && i != wl_get_xbee_id())
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481 | { |
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482 | buf[2*j + 1] = i; |
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483 | buf[2*j + 2] = sensor_matrix_get_reading(sensorMatrix, wl_get_xbee_id(), i); |
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484 | j++; |
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485 | } |
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486 | |||
487 | WL_DEBUG_PRINT("Passing the token to robot ");
|
||
488 | WL_DEBUG_PRINT_INT(buf[0]);
|
||
489 | WL_DEBUG_PRINT(".\r\n");
|
||
490 | wl_send_global_packet(WL_TOKEN_RING_GROUP, WL_TOKEN_PASS, |
||
491 | buf, packetSize, 3);
|
||
492 | |||
493 | wl_token_next_robot = nextRobot; |
||
494 | deathDelay = DEATH_DELAY; |
||
495 | free(buf); |
||
496 | } |
||
497 | |||
498 | /**
|
||
499 | * Called when a packet is received stating that another robot has turned
|
||
500 | * its BOM on. Our BOM is then read, and the data is added to the sensor
|
||
501 | * matrix.
|
||
502 | *
|
||
503 | * @param source the robot whose BOM is on
|
||
504 | **/
|
||
505 | void wl_token_bom_on_receive(int source) |
||
506 | { |
||
507 | WL_DEBUG_PRINT("Robot ");
|
||
508 | WL_DEBUG_PRINT_INT(source); |
||
509 | WL_DEBUG_PRINT(" has flashed its bom.\r\n");
|
||
510 | 196 | bcoltin | |
511 | bom_on_count = 0;
|
||
512 | 138 | bcoltin | |
513 | 17 | bcoltin | sensor_matrix_set_reading(sensorMatrix, wl_get_xbee_id(), |
514 | source, get_max_bom_function()); |
||
515 | } |
||
516 | |||
517 | /**
|
||
518 | * This method is called when we receive the token. Upon receiving
|
||
519 | * the token, we must send a BOM_ON packet, flash the BOM, and send
|
||
520 | * the token to the next robot.
|
||
521 | *
|
||
522 | * If there is a pending request for the token, this is processed first.
|
||
523 | **/
|
||
524 | void wl_token_get_token()
|
||
525 | { |
||
526 | WL_DEBUG_PRINT("We have the token.\r\n");
|
||
527 | if (ringState == ACCEPTED)
|
||
528 | { |
||
529 | sensor_matrix_set_in_ring(sensorMatrix, |
||
530 | wl_get_xbee_id(), 1);
|
||
531 | WL_DEBUG_PRINT("Now a member of the token ring.\r\n");
|
||
532 | ringState = MEMBER; |
||
533 | 190 | bcoltin | joinDelay = -1;
|
534 | 17 | bcoltin | } |
535 | |||
536 | if (ringState == LEAVING || ringState == NONMEMBER)
|
||
537 | { |
||
538 | sensor_matrix_set_in_ring(sensorMatrix, wl_get_xbee_id(), 0);
|
||
539 | if (ringState == NONMEMBER)
|
||
540 | { |
||
541 | WL_DEBUG_PRINT("We should have left the token ring, but didn't.\r\n");
|
||
542 | } |
||
543 | 43 | bcoltin | return;
|
544 | 17 | bcoltin | } |
545 | |||
546 | WL_DEBUG_PRINT("Our BOM has been flashed.\r\n");
|
||
547 | wl_send_global_packet(WL_TOKEN_RING_GROUP, WL_TOKEN_BOM_ON, |
||
548 | NULL, 0, 0); |
||
549 | |||
550 | bom_on_function(); |
||
551 | #ifdef ROBOT
|
||
552 | delay_ms(BOM_DELAY); |
||
553 | #endif
|
||
554 | bom_off_function(); |
||
555 | |||
556 | if (!sensor_matrix_get_in_ring(sensorMatrix, wl_get_xbee_id()))
|
||
557 | { |
||
558 | WL_DEBUG_PRINT("Removed from sensor matrix while flashing BOM.\r\n");
|
||
559 | 166 | bcoltin | return;
|
560 | 17 | bcoltin | } |
561 | |||
562 | wl_token_pass_token(); |
||
563 | } |
||
564 | |||
565 | /**
|
||
566 | * Called when a request to join the token ring is received.
|
||
567 | * If we are the robot preceding the requester in the ring,
|
||
568 | * we respond with a JOIN_ACCEPT packet and pass the token to
|
||
569 | * this robot when we receive the token.
|
||
570 | *
|
||
571 | * @param source the robot who requested to join
|
||
572 | **/
|
||
573 | void wl_token_join_receive(int source) |
||
574 | { |
||
575 | WL_DEBUG_PRINT("Received joining request from robot ");
|
||
576 | WL_DEBUG_PRINT_INT(source); |
||
577 | WL_DEBUG_PRINT(".\r\n");
|
||
578 | |||
579 | //we cannot accept the request if we are not a member
|
||
580 | if (ringState != MEMBER)
|
||
581 | return;
|
||
582 | //if they didn't get our response, see if we should respond again
|
||
583 | if (accepted == source)
|
||
584 | accepted = -1;
|
||
585 | //we can only accept one request at a time
|
||
586 | if (accepted != -1) |
||
587 | return;
|
||
588 | |||
589 | //check if we are the preceding robot in the token ring
|
||
590 | int i = source - 1; |
||
591 | while (1) |
||
592 | { |
||
593 | if (i < 0) |
||
594 | i = sensor_matrix_get_size(sensorMatrix) - 1;
|
||
595 | //we must send a join acceptance
|
||
596 | if (i == wl_get_xbee_id())
|
||
597 | break;
|
||
598 | |||
599 | //another robot will handle it
|
||
600 | if (sensor_matrix_get_in_ring(sensorMatrix, i))
|
||
601 | return;
|
||
602 | i--; |
||
603 | } |
||
604 | |||
605 | accepted = source; |
||
606 | wl_send_robot_to_robot_global_packet(WL_TOKEN_RING_GROUP, WL_TOKEN_JOIN_ACCEPT, |
||
607 | NULL, 0, source, TOKEN_JOIN_ACCEPT_FRAME); |
||
608 | |||
609 | WL_DEBUG_PRINT("Accepting robot ");
|
||
610 | WL_DEBUG_PRINT_INT(source); |
||
611 | WL_DEBUG_PRINT(" into the token ring.\r\n");
|
||
612 | |||
613 | // the token ring has not started yet
|
||
614 | if (sensor_matrix_get_joined(sensorMatrix) == 1) |
||
615 | wl_token_pass_token(); |
||
616 | } |
||
617 | |||
618 | /**
|
||
619 | * Called when we receive a JOIN_ACCEPT packet in attempting to join
|
||
620 | * the token ring.
|
||
621 | * Our attempt to join the ring is stopped, and we wait for the token.
|
||
622 | *
|
||
623 | * @param source the robot who accepted us
|
||
624 | **/
|
||
625 | void wl_token_join_accept_receive(int source) |
||
626 | { |
||
627 | WL_DEBUG_PRINT("Accepted into the token ring by robot ");
|
||
628 | WL_DEBUG_PRINT_INT(source); |
||
629 | WL_DEBUG_PRINT(".\r\n");
|
||
630 | 190 | bcoltin | joinDelay = JOIN_DELAY; |
631 | 17 | bcoltin | ringState = ACCEPTED; |
632 | acceptor = source; |
||
633 | |||
634 | //add ourselves to the token ring
|
||
635 | sensor_matrix_set_in_ring(sensorMatrix, wl_get_xbee_id(), 1);
|
||
636 | } |
||
637 | |||
638 | /**
|
||
639 | 52 | bcoltin | * Returns the number of robots in the token ring.
|
640 | *
|
||
641 | * @return the number of robots in the token ring
|
||
642 | **/
|
||
643 | int wl_token_get_robots_in_ring(void) |
||
644 | { |
||
645 | return sensor_matrix_get_joined(sensorMatrix);
|
||
646 | } |
||
647 | |||
648 | /**
|
||
649 | * Returns true if the specified robot is in the token ring, false
|
||
650 | * otherwise.
|
||
651 | *
|
||
652 | * @param robot the robot to check for whether it is in the token ring
|
||
653 | * @return nonzero if the robot is in the token ring, zero otherwise
|
||
654 | **/
|
||
655 | int wl_token_is_robot_in_ring(int robot) |
||
656 | { |
||
657 | return sensor_matrix_get_in_ring(sensorMatrix, robot);
|
||
658 | } |
||
659 | |||
660 | /**
|
||
661 | * Begins iterating through the robots in the token ring.
|
||
662 | *
|
||
663 | * @see wl_token_iterator_has_next, wl_token_iterator_next
|
||
664 | **/
|
||
665 | void wl_token_iterator_begin(void) |
||
666 | { |
||
667 | 86 | bcoltin | int i = 0; |
668 | 52 | bcoltin | iteratorCount = 0;
|
669 | while (!sensor_matrix_get_in_ring(sensorMatrix, i) &&
|
||
670 | i < sensor_matrix_get_size(sensorMatrix)) |
||
671 | i++; |
||
672 | if (i == sensor_matrix_get_size(sensorMatrix))
|
||
673 | i = -1;
|
||
674 | 108 | bcoltin | iteratorCount = i; |
675 | 52 | bcoltin | } |
676 | |||
677 | /**
|
||
678 | * Returns true if there are more robots in the token ring
|
||
679 | * to iterate through, and false otherwise.
|
||
680 | *
|
||
681 | * @return nonzero if there are more robots to iterate through,
|
||
682 | * zero otherwise
|
||
683 | *
|
||
684 | * @see wl_token_iterator_begin, wl_token_iterator_next
|
||
685 | **/
|
||
686 | int wl_token_iterator_has_next(void) |
||
687 | { |
||
688 | 108 | bcoltin | return iteratorCount != -1; |
689 | 52 | bcoltin | } |
690 | |||
691 | /**
|
||
692 | * Returns the next robot ID in the token ring.
|
||
693 | *
|
||
694 | * @return the next robot ID in the token ring, or -1 if none exists
|
||
695 | *
|
||
696 | * @see wl_token_iterator_begin, wl_token_iterator_has_next
|
||
697 | **/
|
||
698 | int wl_token_iterator_next(void) |
||
699 | { |
||
700 | int result = iteratorCount;
|
||
701 | if (result < 0) |
||
702 | return result;
|
||
703 | |||
704 | iteratorCount++; |
||
705 | while (!sensor_matrix_get_in_ring(sensorMatrix, iteratorCount) &&
|
||
706 | iteratorCount < sensor_matrix_get_size(sensorMatrix)) |
||
707 | iteratorCount++; |
||
708 | if (iteratorCount == sensor_matrix_get_size(sensorMatrix))
|
||
709 | iteratorCount = -1;
|
||
710 | return result;
|
||
711 | } |
||
712 | |||
713 | /**
|
||
714 | 188 | bcoltin | * Returns the number of robots currently in the token ring.
|
715 | 17 | bcoltin | *
|
716 | 188 | bcoltin | * @return the number of robots in the token ring
|
717 | 17 | bcoltin | **/
|
718 | 188 | bcoltin | int wl_token_get_num_robots(void) |
719 | 17 | bcoltin | { |
720 | 188 | bcoltin | return sensor_matrix_get_joined(sensorMatrix);
|
721 | 17 | bcoltin | } |
722 | |||
723 | 188 | bcoltin | /**
|
724 | * Returns the number of robots in the sensor matrix.
|
||
725 | *
|
||
726 | * @return the number of robots in the sensor matrix
|
||
727 | **/
|
||
728 | int wl_token_get_matrix_size(void) |
||
729 | { |
||
730 | return sensor_matrix_get_size(sensorMatrix);
|
||
731 | 48 | jscheine | } |