root / trunk / code / projects / libwireless / lib / wl_token_ring.c @ 242
History | View | Annotate | Download (20.1 KB)
1 |
/**
|
---|---|
2 |
* Copyright (c) 2007 Colony Project
|
3 |
*
|
4 |
* Permission is hereby granted, free of charge, to any person
|
5 |
* obtaining a copy of this software and associated documentation
|
6 |
* files (the "Software"), to deal in the Software without
|
7 |
* restriction, including without limitation the rights to use,
|
8 |
* copy, modify, merge, publish, distribute, sublicense, and/or sell
|
9 |
* copies of the Software, and to permit persons to whom the
|
10 |
* Software is furnished to do so, subject to the following
|
11 |
* conditions:
|
12 |
*
|
13 |
* The above copyright notice and this permission notice shall be
|
14 |
* included in all copies or substantial portions of the Software.
|
15 |
*
|
16 |
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
17 |
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
|
18 |
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
19 |
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
|
20 |
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
|
21 |
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
22 |
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
|
23 |
* OTHER DEALINGS IN THE SOFTWARE.
|
24 |
**/
|
25 |
|
26 |
/**
|
27 |
* @file wl_token_ring.c
|
28 |
* @brief Token Ring Implementation
|
29 |
*
|
30 |
* Implementation of the token ring packet group.
|
31 |
*
|
32 |
* @author Brian Coltin, Colony Project, CMU Robotics Club
|
33 |
**/
|
34 |
|
35 |
#include <wl_token_ring.h> |
36 |
|
37 |
#include <stdlib.h> |
38 |
#include <stdio.h> |
39 |
|
40 |
#include <wl_defs.h> |
41 |
#include <wireless.h> |
42 |
#include <sensor_matrix.h> |
43 |
|
44 |
#ifdef ROBOT
|
45 |
#ifndef FIREFLY
|
46 |
#include <bom.h> |
47 |
#endif
|
48 |
#include <time.h> |
49 |
#endif
|
50 |
|
51 |
#define DEFAULT_SENSOR_MATRIX_SIZE 20 |
52 |
|
53 |
/*Ring States*/
|
54 |
|
55 |
#define NONMEMBER 0 |
56 |
#define MEMBER 1 |
57 |
#define JOINING 2 |
58 |
#define ACCEPTED 3 |
59 |
#define LEAVING 4 |
60 |
|
61 |
/*Frame Types*/
|
62 |
#define TOKEN_JOIN_ACCEPT_FRAME 1 |
63 |
|
64 |
/*Function Prototypes*/
|
65 |
|
66 |
/*Wireless Library Prototypes*/
|
67 |
void wl_token_ring_timeout_handler(void); |
68 |
void wl_token_ring_response_handler(int frame, int received); |
69 |
void wl_token_ring_receive_handler(char type, int source, unsigned char* packet, |
70 |
int length);
|
71 |
void wl_token_ring_cleanup(void); |
72 |
|
73 |
/*Helper Functions*/
|
74 |
void wl_token_pass_token(void); |
75 |
int get_token_distance(int robot1, int robot2); |
76 |
void wl_token_get_token(void); |
77 |
|
78 |
/*Packet Handling Routines*/
|
79 |
void wl_token_pass_receive(int source, char nextRobot, unsigned char* sensorData, int sensorDataLength); |
80 |
void wl_token_bom_on_receive(int source); |
81 |
void wl_token_join_receive(int source); |
82 |
void wl_token_join_accept_receive(int source); |
83 |
|
84 |
/*Global Variables*/
|
85 |
|
86 |
//the sensor matrix
|
87 |
SensorMatrix* sensorMatrix; |
88 |
|
89 |
//the robot we are waiting to say it has received the token. -1 if unspecified
|
90 |
int wl_token_next_robot = -1; |
91 |
|
92 |
//true if the robot should be in the token ring, 0 otherwise
|
93 |
int ringState = NONMEMBER;
|
94 |
//the id of the robot who accepted us into the token ring, only used in ACCEPTED state
|
95 |
int acceptor = -1; |
96 |
//id of the robot we are accepting
|
97 |
int accepted = -1; |
98 |
|
99 |
//the counter for when we assume a robot is dead
|
100 |
int deathDelay = -1; |
101 |
//the counter for joining, before we form our own token ring
|
102 |
int joinDelay = -1; |
103 |
|
104 |
//current robot to check in the iterator
|
105 |
int iteratorCount = 0; |
106 |
|
107 |
// the amount of time a robot has had its BOM on for
|
108 |
int bom_on_count = 0; |
109 |
|
110 |
void do_nothing(void) {} |
111 |
int get_nothing(void) {return -1;} |
112 |
|
113 |
#ifdef ROBOT
|
114 |
#ifndef FIREFLY
|
115 |
void (*bom_on_function) (void) = bom_on; |
116 |
void (*bom_off_function) (void) = bom_off; |
117 |
int (*get_max_bom_function) (void) = get_max_bom; |
118 |
#else
|
119 |
void (*bom_on_function) (void) = do_nothing; |
120 |
void (*bom_off_function) (void) = do_nothing; |
121 |
int (*get_max_bom_function) (void) = get_nothing; |
122 |
#endif
|
123 |
#else
|
124 |
void (*bom_on_function) (void) = do_nothing; |
125 |
void (*bom_off_function) (void) = do_nothing; |
126 |
int (*get_max_bom_function) (void) = get_nothing; |
127 |
#endif
|
128 |
|
129 |
PacketGroupHandler wl_token_ring_handler = |
130 |
{WL_TOKEN_RING_GROUP, wl_token_ring_timeout_handler, |
131 |
wl_token_ring_response_handler, wl_token_ring_receive_handler, |
132 |
wl_token_ring_cleanup}; |
133 |
|
134 |
/**
|
135 |
* Initialize the token ring packet group and register it with the
|
136 |
* wireless library. The robot will not join a token ring.
|
137 |
**/
|
138 |
void wl_token_ring_register()
|
139 |
{ |
140 |
if (wl_get_xbee_id() > 0xFF) |
141 |
{ |
142 |
//Note: if this becomes an issue (unlikely), we could limit sensor information
|
143 |
//to half a byte and use 12 bits for the id
|
144 |
WL_DEBUG_PRINT("XBee ID must be single byte for token ring, is ");
|
145 |
WL_DEBUG_PRINT_INT(wl_get_xbee_id()); |
146 |
WL_DEBUG_PRINT(".\r\n");
|
147 |
return;
|
148 |
} |
149 |
|
150 |
sensorMatrix = sensor_matrix_create(); |
151 |
//add ourselves to the sensor matrix
|
152 |
sensor_matrix_set_in_ring(sensorMatrix, wl_get_xbee_id(), 0);
|
153 |
|
154 |
wl_register_packet_group(&wl_token_ring_handler); |
155 |
} |
156 |
|
157 |
/**
|
158 |
* Removes the packet group from the wireless library.
|
159 |
**/
|
160 |
void wl_token_ring_unregister()
|
161 |
{ |
162 |
wl_unregister_packet_group(&wl_token_ring_handler); |
163 |
} |
164 |
|
165 |
/**
|
166 |
* Sets the functions that are called when the BOM ought to be
|
167 |
* turned on or off. This could be used for things such as
|
168 |
* charging stations, which have multiple BOMs.
|
169 |
*
|
170 |
* @param on_function the function to be called when the BOM
|
171 |
* should be turned on
|
172 |
* @param off_function the function to be called when the BOM
|
173 |
* should be turned off
|
174 |
* @param max_bom_function the function to be called when a
|
175 |
* measurement of the maximum BOM reading is needed.
|
176 |
**/
|
177 |
void wl_token_ring_set_bom_functions(void (*on_function) (void), |
178 |
void (*off_function) (void), int (*max_bom_function) (void)) |
179 |
{ |
180 |
bom_on_function = on_function; |
181 |
bom_off_function = off_function; |
182 |
get_max_bom_function = max_bom_function; |
183 |
} |
184 |
|
185 |
/**
|
186 |
* Called to cleanup the token ring packet group.
|
187 |
**/
|
188 |
void wl_token_ring_cleanup()
|
189 |
{ |
190 |
sensor_matrix_destroy(sensorMatrix); |
191 |
} |
192 |
|
193 |
/**
|
194 |
* Called approximately every quarter second by the wireless library.
|
195 |
**/
|
196 |
void wl_token_ring_timeout_handler()
|
197 |
{ |
198 |
//someone is not responding, assume they are dead
|
199 |
if (deathDelay == 0) |
200 |
{ |
201 |
//pass the token to the next robot if we think someone has died
|
202 |
//also, declare that person dead, as long as it isn't us
|
203 |
if (wl_token_next_robot != wl_get_xbee_id())
|
204 |
{ |
205 |
sensor_matrix_set_in_ring(sensorMatrix, wl_token_next_robot, 0);
|
206 |
WL_DEBUG_PRINT("Robot ");
|
207 |
WL_DEBUG_PRINT_INT(wl_token_next_robot); |
208 |
WL_DEBUG_PRINT(" has died.\r\n");
|
209 |
wl_token_next_robot = -1;
|
210 |
deathDelay = DEATH_DELAY; |
211 |
} |
212 |
|
213 |
// we may have been dropped from the ring when this is received
|
214 |
if (ringState == MEMBER)
|
215 |
wl_token_pass_token(); |
216 |
} |
217 |
|
218 |
//we must start our own token ring, no one is responding to us
|
219 |
if (joinDelay == 0) |
220 |
{ |
221 |
if (sensor_matrix_get_joined(sensorMatrix) == 0) |
222 |
{ |
223 |
WL_DEBUG_PRINT("Creating our own token ring, no robots seem to exist.\r\n");
|
224 |
sensor_matrix_set_in_ring(sensorMatrix, wl_get_xbee_id(), 1);
|
225 |
ringState = MEMBER; |
226 |
//this will make us pass the token to ourself
|
227 |
//repeatedly, and other robots when they join
|
228 |
deathDelay = DEATH_DELAY; |
229 |
wl_token_next_robot = wl_get_xbee_id(); |
230 |
} |
231 |
else
|
232 |
{ |
233 |
WL_DEBUG_PRINT("Attempting to join the token ring again.\r\n");
|
234 |
//attempt to rejoin with a random delay
|
235 |
wl_token_ring_join(); |
236 |
joinDelay = rand() / (RAND_MAX / JOIN_DELAY) + 1;
|
237 |
} |
238 |
} |
239 |
|
240 |
if (deathDelay >= 0) |
241 |
deathDelay--; |
242 |
if (joinDelay >= 0) |
243 |
joinDelay--; |
244 |
if (bom_on_count >= 0) |
245 |
bom_on_count++; |
246 |
} |
247 |
|
248 |
/**
|
249 |
* Called when the XBee tells us if a packet we sent has been received.
|
250 |
*
|
251 |
* @param frame the frame number assigned when the packet was sent
|
252 |
* @param received 1 if the packet was received, 0 otherwise
|
253 |
**/
|
254 |
void wl_token_ring_response_handler(int frame, int received) |
255 |
{ |
256 |
if (!received)
|
257 |
{ |
258 |
WL_DEBUG_PRINT("FAILED.\r\n");
|
259 |
} |
260 |
} |
261 |
|
262 |
/**
|
263 |
* Called when we recieve a token ring packet.
|
264 |
* @param type the type of the packet
|
265 |
* @param source the id of the robot who sent the packet
|
266 |
* @param packet the data in the packet
|
267 |
* @param length the length of the packet in bytes
|
268 |
**/
|
269 |
void wl_token_ring_receive_handler(char type, int source, unsigned char* packet, |
270 |
int length)
|
271 |
{ |
272 |
switch (type)
|
273 |
{ |
274 |
case WL_TOKEN_PASS:
|
275 |
if (length < 1) |
276 |
{ |
277 |
WL_DEBUG_PRINT("Malformed Token Pass packet received.\r\n");
|
278 |
return;
|
279 |
} |
280 |
wl_token_pass_receive(source, packet[0], packet + 1, length - 1); |
281 |
break;
|
282 |
case WL_TOKEN_BOM_ON:
|
283 |
//add the robot to the sensor matrix if it is not already there
|
284 |
wl_token_bom_on_receive(source); |
285 |
break;
|
286 |
case WL_TOKEN_JOIN:
|
287 |
wl_token_join_receive(source); |
288 |
break;
|
289 |
case WL_TOKEN_JOIN_ACCEPT:
|
290 |
wl_token_join_accept_receive(source); |
291 |
break;
|
292 |
default:
|
293 |
WL_DEBUG_PRINT("Unimplemented token ring packet received.\r\n");
|
294 |
break;
|
295 |
} |
296 |
} |
297 |
|
298 |
/**
|
299 |
* Causes the robot to join an existing token ring, or create one
|
300 |
* if no token ring exists. The token ring uses global and robot to robot
|
301 |
* packets, and does not rely on any PAN.
|
302 |
**/
|
303 |
void wl_token_ring_join()
|
304 |
{ |
305 |
WL_DEBUG_PRINT("Joining the token ring.\r\n");
|
306 |
ringState = JOINING; |
307 |
joinDelay = DEATH_DELAY * 2;
|
308 |
wl_send_global_packet(WL_TOKEN_RING_GROUP, WL_TOKEN_JOIN, |
309 |
NULL, 0, 0); |
310 |
} |
311 |
|
312 |
/**
|
313 |
* Causes the robot to leave the token ring. The robot stops
|
314 |
* alerting others of its location, but continues storing the
|
315 |
* locations of other robots.
|
316 |
**/
|
317 |
void wl_token_ring_leave()
|
318 |
{ |
319 |
ringState = LEAVING; |
320 |
} |
321 |
|
322 |
/**
|
323 |
* Returns the BOM reading robot source has for robot dest.
|
324 |
*
|
325 |
* @param source the robot that made the BOM reading
|
326 |
* @param dest the robot whose relative location is returned
|
327 |
*
|
328 |
* @return a BOM reading from robot source to robot dest,
|
329 |
* in the range 0-15, or -1 if it is unknown
|
330 |
**/
|
331 |
int wl_token_get_sensor_reading(int source, int dest) |
332 |
{ |
333 |
if (wl_token_is_robot_in_ring(dest) &&
|
334 |
(source == wl_get_xbee_id() || wl_token_is_robot_in_ring(source))) |
335 |
return sensor_matrix_get_reading(sensorMatrix, source, dest);
|
336 |
return -1; |
337 |
} |
338 |
|
339 |
/**
|
340 |
* Returns the BOM reading we have for robot dest.
|
341 |
*
|
342 |
* @param dest the robot whose relative location is returned
|
343 |
*
|
344 |
* @return a BOM reading from us to robot dest, in the range
|
345 |
* 0-15, or -1 if it is unkown
|
346 |
**/
|
347 |
int wl_token_get_my_sensor_reading(int dest) |
348 |
{ |
349 |
return wl_token_get_sensor_reading(wl_get_xbee_id(), dest);
|
350 |
} |
351 |
|
352 |
/**
|
353 |
* This method is called when we receive a token pass packet.
|
354 |
* @param source is the robot it came from
|
355 |
* @param nextRobot is the robot the token was passed to
|
356 |
* @param sensorData a char with an id followed by a char with the sensor
|
357 |
* reading for that robot, repeated for sensorDataLength bytes
|
358 |
* @param sensorDataLength the length in bytes of sensorData
|
359 |
*/
|
360 |
void wl_token_pass_receive(int source, char nextRobot, unsigned char* sensorData, int sensorDataLength) |
361 |
{ |
362 |
int i, j;
|
363 |
|
364 |
// this prevents two tokens from being passed around at a time (second clause is in case we are joining)
|
365 |
if (source != wl_token_next_robot && bom_on_count <= DEATH_DELAY / 2 && |
366 |
ringState != ACCEPTED) |
367 |
{ |
368 |
WL_DEBUG_PRINT("Received token pass when a robot should not have died yet.\n");
|
369 |
WL_DEBUG_PRINT("There are probably two tokens going around, packet ignored.\n");
|
370 |
return;
|
371 |
} |
372 |
|
373 |
bom_on_count = -1;
|
374 |
deathDelay = -1;
|
375 |
WL_DEBUG_PRINT("Received the token from robot");
|
376 |
WL_DEBUG_PRINT_INT(source); |
377 |
WL_DEBUG_PRINT(", next robot is ");
|
378 |
WL_DEBUG_PRINT_INT((int)nextRobot);
|
379 |
WL_DEBUG_PRINT(" \r\n");
|
380 |
sensor_matrix_set_in_ring(sensorMatrix, source, 1);
|
381 |
|
382 |
//with this packet, we are passed the id of the next robot in the ring
|
383 |
//and the sensor matrix, a list of id and sensor reading pairs (two bytes for both)
|
384 |
j = 0;
|
385 |
for (i = 0; i < sensor_matrix_get_size(sensorMatrix); i++) |
386 |
{ |
387 |
if (i == source)
|
388 |
continue;
|
389 |
|
390 |
//set the sensor information we receive
|
391 |
if (j < sensorDataLength / 2 && sensorData[2 * j] == i) |
392 |
{ |
393 |
//the robot we were going to accept has already been accepted
|
394 |
if (accepted == i)
|
395 |
{ |
396 |
accepted = -1;
|
397 |
WL_DEBUG_PRINT("Someone accepted the robot we did.\r\n");
|
398 |
} |
399 |
sensor_matrix_set_reading(sensorMatrix, source, i, |
400 |
sensorData[2 * j + 1]); |
401 |
sensor_matrix_set_in_ring(sensorMatrix, i, 1);
|
402 |
j++; |
403 |
} |
404 |
else
|
405 |
{ |
406 |
if (sensor_matrix_get_in_ring(sensorMatrix, i))
|
407 |
{ |
408 |
WL_DEBUG_PRINT("Robot ");
|
409 |
WL_DEBUG_PRINT_INT(i); |
410 |
WL_DEBUG_PRINT(" has been removed from the sensor matrix of robot ");
|
411 |
WL_DEBUG_PRINT_INT(wl_get_xbee_id()); |
412 |
WL_DEBUG_PRINT(" due to a packet from robot ");
|
413 |
WL_DEBUG_PRINT_INT(source); |
414 |
WL_DEBUG_PRINT(".\r\n");
|
415 |
sensor_matrix_set_in_ring(sensorMatrix, i, 0);
|
416 |
} |
417 |
|
418 |
if (i == wl_get_xbee_id() && ringState == MEMBER)
|
419 |
{ |
420 |
ringState = NONMEMBER; |
421 |
wl_token_ring_join(); |
422 |
|
423 |
WL_DEBUG_PRINT("We have been removed from the ring ");
|
424 |
WL_DEBUG_PRINT("and are rejoining.\r\n");
|
425 |
} |
426 |
|
427 |
//the person who accepted us is dead... let's ask again
|
428 |
if (i == acceptor)
|
429 |
{ |
430 |
sensor_matrix_set_in_ring(sensorMatrix, |
431 |
wl_get_xbee_id(), 1);
|
432 |
ringState = NONMEMBER; |
433 |
acceptor = -1;
|
434 |
wl_token_ring_join(); |
435 |
} |
436 |
} |
437 |
} |
438 |
|
439 |
wl_token_next_robot = nextRobot; |
440 |
|
441 |
deathDelay = get_token_distance(wl_get_xbee_id(), nextRobot) * DEATH_DELAY; |
442 |
|
443 |
//we have the token
|
444 |
if (wl_token_next_robot == wl_get_xbee_id())
|
445 |
wl_token_get_token(); |
446 |
} |
447 |
|
448 |
/**
|
449 |
* Gets the distance in the token ring between two robots.
|
450 |
*
|
451 |
* @param robot1 the first robot
|
452 |
* @param robot2 the second robot
|
453 |
*
|
454 |
* @return the number of passes before the token is expected
|
455 |
* to reach robot2 from robot1
|
456 |
**/
|
457 |
int get_token_distance(int robot1, int robot2) |
458 |
{ |
459 |
int curr = robot1 + 1; |
460 |
int count = 1; |
461 |
while (1) |
462 |
{ |
463 |
if (curr == sensor_matrix_get_size(sensorMatrix))
|
464 |
curr = 0;
|
465 |
if (curr == robot2)
|
466 |
break;
|
467 |
if (sensor_matrix_get_in_ring(sensorMatrix, curr))
|
468 |
count++; |
469 |
curr++; |
470 |
} |
471 |
return count;
|
472 |
} |
473 |
|
474 |
/**
|
475 |
* Passes the token to the next robot in the token ring.
|
476 |
**/
|
477 |
void wl_token_pass_token()
|
478 |
{ |
479 |
char nextRobot;
|
480 |
int i = wl_get_xbee_id() + 1; |
481 |
if (accepted == -1) |
482 |
{ |
483 |
while (1) |
484 |
{ |
485 |
if (i == sensor_matrix_get_size(sensorMatrix))
|
486 |
i = 0;
|
487 |
if (sensor_matrix_get_in_ring(sensorMatrix, i))
|
488 |
{ |
489 |
nextRobot = (char)i;
|
490 |
break;
|
491 |
} |
492 |
i++; |
493 |
} |
494 |
} |
495 |
else
|
496 |
{ |
497 |
WL_DEBUG_PRINT("Accepting new robot, sending it the token.\r\n");
|
498 |
//add a new robot to the token ring
|
499 |
sensor_matrix_set_in_ring(sensorMatrix, accepted, 1);
|
500 |
nextRobot = accepted; |
501 |
accepted = -1;
|
502 |
} |
503 |
|
504 |
//we don't include ourself
|
505 |
int packetSize = 1 + 2 * (sensor_matrix_get_joined(sensorMatrix) - 1); |
506 |
char* buf = (char*)malloc(packetSize * sizeof(char)); |
507 |
if (!buf)
|
508 |
{ |
509 |
WL_DEBUG_PRINT_INT(packetSize); |
510 |
WL_DEBUG_PRINT("Out of memory - pass token.\r\n");
|
511 |
return;
|
512 |
} |
513 |
buf[0] = nextRobot;
|
514 |
|
515 |
int j = 0; |
516 |
for (i = 0; i < sensor_matrix_get_size(sensorMatrix); i++) |
517 |
if (sensor_matrix_get_in_ring(sensorMatrix, i) && i != wl_get_xbee_id())
|
518 |
{ |
519 |
buf[2*j + 1] = i; |
520 |
buf[2*j + 2] = sensor_matrix_get_reading(sensorMatrix, wl_get_xbee_id(), i); |
521 |
j++; |
522 |
} |
523 |
|
524 |
WL_DEBUG_PRINT("Passing the token to robot ");
|
525 |
WL_DEBUG_PRINT_INT(buf[0]);
|
526 |
WL_DEBUG_PRINT(".\r\n");
|
527 |
wl_send_global_packet(WL_TOKEN_RING_GROUP, WL_TOKEN_PASS, |
528 |
buf, packetSize, 3);
|
529 |
|
530 |
wl_token_next_robot = nextRobot; |
531 |
deathDelay = DEATH_DELAY; |
532 |
free(buf); |
533 |
} |
534 |
|
535 |
/**
|
536 |
* Called when a packet is received stating that another robot has turned
|
537 |
* its BOM on. Our BOM is then read, and the data is added to the sensor
|
538 |
* matrix.
|
539 |
*
|
540 |
* @param source the robot whose BOM is on
|
541 |
**/
|
542 |
void wl_token_bom_on_receive(int source) |
543 |
{ |
544 |
WL_DEBUG_PRINT("Robot ");
|
545 |
WL_DEBUG_PRINT_INT(source); |
546 |
WL_DEBUG_PRINT(" has flashed its bom.\r\n");
|
547 |
|
548 |
bom_on_count = 0;
|
549 |
|
550 |
sensor_matrix_set_reading(sensorMatrix, wl_get_xbee_id(), |
551 |
source, get_max_bom_function()); |
552 |
} |
553 |
|
554 |
/**
|
555 |
* This method is called when we receive the token. Upon receiving
|
556 |
* the token, we must send a BOM_ON packet, flash the BOM, and send
|
557 |
* the token to the next robot.
|
558 |
*
|
559 |
* If there is a pending request for the token, this is processed first.
|
560 |
**/
|
561 |
void wl_token_get_token()
|
562 |
{ |
563 |
WL_DEBUG_PRINT("We have the token.\r\n");
|
564 |
if (ringState == ACCEPTED)
|
565 |
{ |
566 |
sensor_matrix_set_in_ring(sensorMatrix, |
567 |
wl_get_xbee_id(), 1);
|
568 |
WL_DEBUG_PRINT("Now a member of the token ring.\r\n");
|
569 |
ringState = MEMBER; |
570 |
joinDelay = -1;
|
571 |
} |
572 |
|
573 |
if (ringState == LEAVING || ringState == NONMEMBER)
|
574 |
{ |
575 |
sensor_matrix_set_in_ring(sensorMatrix, wl_get_xbee_id(), 0);
|
576 |
if (ringState == NONMEMBER)
|
577 |
{ |
578 |
WL_DEBUG_PRINT("We should have left the token ring, but didn't.\r\n");
|
579 |
} |
580 |
return;
|
581 |
} |
582 |
|
583 |
WL_DEBUG_PRINT("Our BOM has been flashed.\r\n");
|
584 |
wl_send_global_packet(WL_TOKEN_RING_GROUP, WL_TOKEN_BOM_ON, |
585 |
NULL, 0, 0); |
586 |
|
587 |
bom_on_function(); |
588 |
#ifdef ROBOT
|
589 |
delay_ms(BOM_DELAY); |
590 |
#endif
|
591 |
bom_off_function(); |
592 |
|
593 |
if (!sensor_matrix_get_in_ring(sensorMatrix, wl_get_xbee_id()))
|
594 |
{ |
595 |
WL_DEBUG_PRINT("Removed from sensor matrix while flashing BOM.\r\n");
|
596 |
return;
|
597 |
} |
598 |
|
599 |
wl_token_pass_token(); |
600 |
} |
601 |
|
602 |
/**
|
603 |
* Called when a request to join the token ring is received.
|
604 |
* If we are the robot preceding the requester in the ring,
|
605 |
* we respond with a JOIN_ACCEPT packet and pass the token to
|
606 |
* this robot when we receive the token.
|
607 |
*
|
608 |
* @param source the robot who requested to join
|
609 |
**/
|
610 |
void wl_token_join_receive(int source) |
611 |
{ |
612 |
WL_DEBUG_PRINT("Received joining request from robot ");
|
613 |
WL_DEBUG_PRINT_INT(source); |
614 |
WL_DEBUG_PRINT(".\r\n");
|
615 |
|
616 |
//we cannot accept the request if we are not a member
|
617 |
if (ringState != MEMBER)
|
618 |
return;
|
619 |
//if they didn't get our response, see if we should respond again
|
620 |
if (accepted == source)
|
621 |
accepted = -1;
|
622 |
//we can only accept one request at a time
|
623 |
if (accepted != -1) |
624 |
return;
|
625 |
|
626 |
//check if we are the preceding robot in the token ring
|
627 |
int i = source - 1; |
628 |
while (1) |
629 |
{ |
630 |
if (i < 0) |
631 |
i = sensor_matrix_get_size(sensorMatrix) - 1;
|
632 |
//we must send a join acceptance
|
633 |
if (i == wl_get_xbee_id())
|
634 |
break;
|
635 |
|
636 |
//another robot will handle it
|
637 |
if (sensor_matrix_get_in_ring(sensorMatrix, i))
|
638 |
return;
|
639 |
i--; |
640 |
} |
641 |
|
642 |
accepted = source; |
643 |
wl_send_robot_to_robot_global_packet(WL_TOKEN_RING_GROUP, WL_TOKEN_JOIN_ACCEPT, |
644 |
NULL, 0, source, TOKEN_JOIN_ACCEPT_FRAME); |
645 |
|
646 |
WL_DEBUG_PRINT("Accepting robot ");
|
647 |
WL_DEBUG_PRINT_INT(source); |
648 |
WL_DEBUG_PRINT(" into the token ring.\r\n");
|
649 |
|
650 |
// the token ring has not started yet
|
651 |
if (sensor_matrix_get_joined(sensorMatrix) == 1) |
652 |
wl_token_pass_token(); |
653 |
} |
654 |
|
655 |
/**
|
656 |
* Called when we receive a JOIN_ACCEPT packet in attempting to join
|
657 |
* the token ring.
|
658 |
* Our attempt to join the ring is stopped, and we wait for the token.
|
659 |
*
|
660 |
* @param source the robot who accepted us
|
661 |
**/
|
662 |
void wl_token_join_accept_receive(int source) |
663 |
{ |
664 |
WL_DEBUG_PRINT("Accepted into the token ring by robot ");
|
665 |
WL_DEBUG_PRINT_INT(source); |
666 |
WL_DEBUG_PRINT(".\r\n");
|
667 |
joinDelay = JOIN_DELAY; |
668 |
ringState = ACCEPTED; |
669 |
acceptor = source; |
670 |
|
671 |
//add ourselves to the token ring
|
672 |
sensor_matrix_set_in_ring(sensorMatrix, wl_get_xbee_id(), 1);
|
673 |
} |
674 |
|
675 |
/**
|
676 |
* Returns the number of robots in the token ring.
|
677 |
*
|
678 |
* @return the number of robots in the token ring
|
679 |
**/
|
680 |
int wl_token_get_robots_in_ring(void) |
681 |
{ |
682 |
return sensor_matrix_get_joined(sensorMatrix);
|
683 |
} |
684 |
|
685 |
/**
|
686 |
* Returns true if the specified robot is in the token ring, false
|
687 |
* otherwise.
|
688 |
*
|
689 |
* @param robot the robot to check for whether it is in the token ring
|
690 |
* @return nonzero if the robot is in the token ring, zero otherwise
|
691 |
**/
|
692 |
int wl_token_is_robot_in_ring(int robot) |
693 |
{ |
694 |
return sensor_matrix_get_in_ring(sensorMatrix, robot);
|
695 |
} |
696 |
|
697 |
/**
|
698 |
* Begins iterating through the robots in the token ring.
|
699 |
*
|
700 |
* @see wl_token_iterator_has_next, wl_token_iterator_next
|
701 |
**/
|
702 |
void wl_token_iterator_begin(void) |
703 |
{ |
704 |
int i = 0; |
705 |
iteratorCount = 0;
|
706 |
while (!sensor_matrix_get_in_ring(sensorMatrix, i) &&
|
707 |
i < sensor_matrix_get_size(sensorMatrix)) |
708 |
i++; |
709 |
if (i == sensor_matrix_get_size(sensorMatrix))
|
710 |
i = -1;
|
711 |
iteratorCount = i; |
712 |
} |
713 |
|
714 |
/**
|
715 |
* Returns true if there are more robots in the token ring
|
716 |
* to iterate through, and false otherwise.
|
717 |
*
|
718 |
* @return nonzero if there are more robots to iterate through,
|
719 |
* zero otherwise
|
720 |
*
|
721 |
* @see wl_token_iterator_begin, wl_token_iterator_next
|
722 |
**/
|
723 |
int wl_token_iterator_has_next(void) |
724 |
{ |
725 |
return iteratorCount != -1; |
726 |
} |
727 |
|
728 |
/**
|
729 |
* Returns the next robot ID in the token ring.
|
730 |
*
|
731 |
* @return the next robot ID in the token ring, or -1 if none exists
|
732 |
*
|
733 |
* @see wl_token_iterator_begin, wl_token_iterator_has_next
|
734 |
**/
|
735 |
int wl_token_iterator_next(void) |
736 |
{ |
737 |
int result = iteratorCount;
|
738 |
if (result < 0) |
739 |
return result;
|
740 |
|
741 |
iteratorCount++; |
742 |
while (!sensor_matrix_get_in_ring(sensorMatrix, iteratorCount) &&
|
743 |
iteratorCount < sensor_matrix_get_size(sensorMatrix)) |
744 |
iteratorCount++; |
745 |
if (iteratorCount == sensor_matrix_get_size(sensorMatrix))
|
746 |
iteratorCount = -1;
|
747 |
return result;
|
748 |
} |
749 |
|
750 |
/**
|
751 |
* Returns the number of robots currently in the token ring.
|
752 |
*
|
753 |
* @return the number of robots in the token ring
|
754 |
**/
|
755 |
int wl_token_get_num_robots(void) |
756 |
{ |
757 |
return sensor_matrix_get_joined(sensorMatrix);
|
758 |
} |
759 |
|
760 |
/**
|
761 |
* Returns the number of robots in the sensor matrix.
|
762 |
*
|
763 |
* @return the number of robots in the sensor matrix
|
764 |
**/
|
765 |
int wl_token_get_matrix_size(void) |
766 |
{ |
767 |
return sensor_matrix_get_size(sensorMatrix);
|
768 |
} |
769 |
|