root / branches / simulator / projects / simulator / simulator / core / robot.c @ 1010
History | View | Annotate | Download (5.06 KB)
1 |
/**
|
---|---|
2 |
* @file robot.c
|
3 |
* @author Colony Project
|
4 |
* @brief Simulator Robot Management
|
5 |
*
|
6 |
* Contains implementations of functions managing robots
|
7 |
* in the simulator, including process control and memory
|
8 |
* management.
|
9 |
**/
|
10 |
|
11 |
#include <stdlib.h> |
12 |
#include <stdio.h> |
13 |
#include <string.h> |
14 |
|
15 |
#include <unistd.h> |
16 |
#include <signal.h> |
17 |
#include <sys/wait.h> |
18 |
#include <robot_shared.h> |
19 |
#include <sys/ipc.h> |
20 |
#include <sys/types.h> |
21 |
#include <sys/shm.h> |
22 |
#include <errno.h> |
23 |
#include <pthread.h> |
24 |
|
25 |
#include "robot.h" |
26 |
#include "motion.h" |
27 |
#include "gtk_gui.h" |
28 |
|
29 |
void sig_chld_handler(int sig); |
30 |
void robot_update(int i); |
31 |
|
32 |
// global variables
|
33 |
int first_available_id = 0; |
34 |
// an expanding array of robots
|
35 |
Robot* robots = NULL;
|
36 |
int robots_size = 0; |
37 |
int num_robots = 0; |
38 |
|
39 |
int iterator_pos = 0; |
40 |
|
41 |
// signalled when all robots have run for a bit
|
42 |
pthread_mutex_t all_finished_mutex; |
43 |
pthread_cond_t all_finished_cond; |
44 |
int finished = 0; |
45 |
|
46 |
int robots_initialize(void) |
47 |
{ |
48 |
int i;
|
49 |
if (signal(SIGCHLD, sig_chld_handler) == SIG_ERR)
|
50 |
return -1; |
51 |
|
52 |
robots_size = 10;
|
53 |
robots = (Robot*)malloc(sizeof(Robot) * robots_size);
|
54 |
if (!robots)
|
55 |
return -1; |
56 |
memset(robots, 0, sizeof(Robot) * robots_size); |
57 |
for (i = 0; i < robots_size; i++) |
58 |
robots[i].id = -1;
|
59 |
|
60 |
finished = 0;
|
61 |
pthread_mutex_init(&all_finished_mutex, NULL);
|
62 |
pthread_cond_init(&all_finished_cond, NULL);
|
63 |
|
64 |
return 0; |
65 |
} |
66 |
|
67 |
/**
|
68 |
* Creates a new robot. Returns its id on
|
69 |
* success, or a negative integer on failure.
|
70 |
**/
|
71 |
int robot_create(char *execname) |
72 |
{ |
73 |
int pid;
|
74 |
int id = first_available_id;
|
75 |
Robot* r = &robots[id]; |
76 |
printf("ID: %d\n", id);
|
77 |
// do shared memory stuff here
|
78 |
key_t key = IPC_PRIVATE; |
79 |
//Memory accessible only to children with r/w privileges
|
80 |
r->sharedMemID = shmget(key, sizeof(RobotShared), IPC_CREAT | 0666); |
81 |
|
82 |
if(r->sharedMemID < 0) |
83 |
{ |
84 |
fprintf(stderr, "Failed to get shared memory.\n");
|
85 |
return -1; |
86 |
} |
87 |
|
88 |
r->shared = (RobotShared*)shmat(r->sharedMemID, NULL, 0); |
89 |
|
90 |
if(!(r->shared))
|
91 |
{ |
92 |
//Free shared memory region
|
93 |
if (!shmctl(r->sharedMemID, IPC_RMID, NULL)) |
94 |
fprintf(stderr, "Failed to free shared memory.\n");
|
95 |
|
96 |
fprintf(stderr, "Error attaching memory to parent.\n");
|
97 |
return -1; |
98 |
} |
99 |
|
100 |
// Initialize robot structure here
|
101 |
r->shared->motor1 = 0;
|
102 |
r->shared->motor2 = 0;
|
103 |
r->id = id; |
104 |
|
105 |
if((pid = fork()) < 0) |
106 |
{ |
107 |
//Free Shared Memory Region
|
108 |
if (!shmdt(r->shared))
|
109 |
fprintf(stderr, "Failed to free shared memory.\n");
|
110 |
|
111 |
if (!shmctl(r->sharedMemID, IPC_RMID, NULL)) |
112 |
fprintf(stderr, "Failed to free shared memory.\n");
|
113 |
|
114 |
r->id = -1;
|
115 |
fprintf(stderr, "Failed to fork robot process.\n");
|
116 |
return -1; |
117 |
} |
118 |
|
119 |
|
120 |
if(!pid)
|
121 |
{ |
122 |
char var[21]; |
123 |
/* restore default sigchld handler */
|
124 |
signal(SIGCHLD, SIG_DFL); |
125 |
sprintf(var, "memory_id=%d", r->sharedMemID);
|
126 |
putenv(var); |
127 |
//TODO: keep the other env. stuff around
|
128 |
execv(execname, NULL);
|
129 |
fprintf(stderr, "exec failed to run child process.\n");
|
130 |
exit(-1);
|
131 |
} |
132 |
else
|
133 |
{ |
134 |
r->pid = pid; |
135 |
do {
|
136 |
first_available_id++; |
137 |
} while (first_available_id < robots_size &&
|
138 |
robots[first_available_id].id != -1);
|
139 |
// resize the array if necessary
|
140 |
if (first_available_id >= robots_size)
|
141 |
{ |
142 |
robots_size *= 2;
|
143 |
robots = realloc(robots, sizeof(Robot) * robots_size);
|
144 |
if (!robots)
|
145 |
{ |
146 |
fprintf(stderr, "Out of memory.\n");
|
147 |
return -1; |
148 |
} |
149 |
} |
150 |
} |
151 |
|
152 |
num_robots++; |
153 |
|
154 |
return id;
|
155 |
} |
156 |
|
157 |
/**
|
158 |
* Frees all resources associated with a robot, including
|
159 |
* killing its process if necessary.
|
160 |
*
|
161 |
* @return zero on success, nonzero on failure
|
162 |
**/
|
163 |
int robot_destroy(int id) |
164 |
{ |
165 |
Robot* r; |
166 |
|
167 |
if (id < 0 || id >= robots_size) |
168 |
return -1; |
169 |
r = &robots[id]; |
170 |
if (r->id == 0) |
171 |
return -1; |
172 |
|
173 |
if (!shmdt(r->shared))
|
174 |
{ |
175 |
fprintf(stderr, "Failed to free shared memory.\n");
|
176 |
return -1; |
177 |
} |
178 |
if (!shmctl(r->sharedMemID, IPC_RMID, NULL)) |
179 |
{ |
180 |
fprintf(stderr, "Failed to free shared memory.\n");
|
181 |
return -1; |
182 |
} |
183 |
|
184 |
memset(r, 0, sizeof(Robot)); |
185 |
r->id = -1;
|
186 |
|
187 |
if (id < first_available_id)
|
188 |
first_available_id = 0;
|
189 |
|
190 |
return 0; |
191 |
} |
192 |
|
193 |
void robot_iterator_reset(void) |
194 |
{ |
195 |
iterator_pos = -1;
|
196 |
} |
197 |
|
198 |
// note: addresses may change, replace with
|
199 |
// allocated memory
|
200 |
Robot* robot_iterator_next(void)
|
201 |
{ |
202 |
if (iterator_pos >= robots_size)
|
203 |
return NULL; |
204 |
do iterator_pos++;
|
205 |
while (iterator_pos < robots_size &&
|
206 |
robots[iterator_pos].id == -1);
|
207 |
|
208 |
if (iterator_pos >= robots_size)
|
209 |
return NULL; |
210 |
|
211 |
return &(robots[iterator_pos]);
|
212 |
} |
213 |
|
214 |
void sig_chld_handler(int sig) |
215 |
{ |
216 |
pthread_mutex_lock(&all_finished_mutex); |
217 |
finished++; |
218 |
if (finished >= num_robots)
|
219 |
{ |
220 |
pthread_cond_signal(&all_finished_cond); |
221 |
} |
222 |
pthread_mutex_unlock(&all_finished_mutex); |
223 |
} |
224 |
|
225 |
void* robot_event_loop(void* arg) |
226 |
{ |
227 |
int i;
|
228 |
//TODO: errors
|
229 |
|
230 |
while (1) |
231 |
{ |
232 |
pthread_mutex_lock(&all_finished_mutex); |
233 |
// TODO: race condition for adding robots?
|
234 |
if (finished < num_robots)
|
235 |
{ |
236 |
pthread_cond_wait(&all_finished_cond, &all_finished_mutex); |
237 |
} |
238 |
finished = 0;
|
239 |
pthread_mutex_unlock(&all_finished_mutex); |
240 |
for (i = 0; i < robots_size; i++) |
241 |
if (robots[i].id != -1) |
242 |
robot_update(i); |
243 |
for (i = 0; i < robots_size; i++) |
244 |
{ |
245 |
if (robots[i].id == -1) |
246 |
continue;
|
247 |
kill(robots[i].pid, SIGCONT); |
248 |
} |
249 |
|
250 |
gui_refresh(); |
251 |
} |
252 |
} |
253 |
|
254 |
void robot_update(int i) |
255 |
{ |
256 |
Robot* r = &(robots[i]); |
257 |
if (r->id == -1) |
258 |
return;
|
259 |
move_robot(r); |
260 |
} |
261 |
|