int/main.c

   1 #include <netdb.h>
   2 #include <netinet/in.h>
   3 #include <signal.h>
   4 #include <stdbool.h>
   5 #include <stdint.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <sys/socket.h>
  10 #include <sys/types.h>
  11 #include <sys/time.h>
  12 #include <unistd.h>
  13
  14 #include "interpret.h"
  15 #include "mTaskSymbols.h"
  16 #include "sds.h"
  17 #include "task.h"
  18 #include "misc.h"
  19
  20 #define MAXSDS 50
  21
  22 #define MSG_GET_TASK 't'
  23 #define MSG_DEL_TASK 'd'
  24 #define MSG_SDS_SPEC 's'
  25 #define MSG_SDS_UPD 'u'
  26
  27 struct timeval tv1;
  28 int sock_fd = -1;
  29 int fd = -1;
  30 int port = 8123;
  31
  32 void killHandler(int i)
  33 {
  34         printf("%s caught, Bye...\n", strsignal(i));
  35         exit(1);
  36 }
  37
  38 bool input_available(int fd){
  39         struct timeval tv;
  40         fd_set fds;
  41         tv.tv_sec = 0;
  42         tv.tv_usec = 0;
  43         FD_ZERO(&fds);
  44         FD_SET(fd, &fds);
  45         if (select(fd+1, &fds, NULL, NULL, &tv) == -1)
  46                 pdie("select");
  47         return FD_ISSET(fd, &fds);
  48 }
  49
  50 long millis() {
  51         if (gettimeofday(&tv1, NULL) == -1)
  52                 pdie("gettimeofday");
  53         return tv1.tv_sec*1000 + tv1.tv_usec/1000;
  54 }
  55
  56 void read_message(int fd_in, int fd_out)
  57 {
  58         uint8_t c;
  59         //Find next task
  60
  61         read(fd_in, &c, 1);
  62         debug("Receiving input: %c\n", c);
  63         switch(c){
  64         case MSG_SDS_SPEC:
  65                 debug("Receiving an sds\n");
  66                 sds_register(fd_in);
  67                 break;
  68         case MSG_SDS_UPD:
  69                 debug("Receiving an sds\n");
  70                 //TODO do something with the return value
  71                 sds_update(fd_in);
  72                 break;
  73         case MSG_DEL_TASK:
  74                 debug("Receiving a delete task request\n");
  75                 task_delete(fd);
  76                 break;
  77         case MSG_GET_TASK:
  78                 debug("Receiving a task\n");
  79                 c = task_register(fd_in);
  80                 write(fd_out, &c, 1);
  81                 break;
  82         default:
  83                 debug("Unknown message: %X?\n", c);
  84         }
  85 }
  86
  87 void open_filedescriptors()
  88 {
  89         struct sockaddr_in sa;
  90
  91         bzero((char *) &sa, sizeof(sa));
  92         sa.sin_family = AF_INET;
  93         sa.sin_addr.s_addr = INADDR_ANY;
  94         sa.sin_port = htons(port);
  95
  96         if((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
  97                 pdie("socket");
  98         if(bind(sock_fd, (struct sockaddr*)&sa, sizeof(sa)) == -1)
  99                 pdie("bind\n");
 100         if(listen(sock_fd, 10) == -1)
 101                 pdie("bind\n");
 102
 103         printf("Listening on %d\n", port);
 104         fflush(stdout);
 105         if((fd = accept(sock_fd, (struct sockaddr*)NULL, NULL)) == -1)
 106                 pdie("accept");
 107 }
 108
 109 void usage(FILE *o, char *arg0){
 110         fprintf(o,
 111                 "Usage: %s [opts]\n"
 112                 "\n"
 113                 "Options\n"
 114                 "-p PORT  Custom port number, default: 8123\n"
 115                 , arg0);
 116 }
 117
 118 int main(int argc, char *argv[])
 119 {
 120         int ct;
 121
 122         //Register signal handler
 123         if(signal(SIGINT, killHandler) == SIG_ERR){
 124                 die("Couldn't register signal handler...\n");
 125         }
 126         if(signal(SIGTERM, killHandler) == SIG_ERR){
 127                 die("Couldn't register signal handler...\n");
 128         }
 129
 130         //Command line arguments
 131         int opt;
 132         while((opt = getopt(argc, argv, "hp:")) != -1){
 133                 switch(opt){
 134                         case 'p':
 135                                 port = atoi(optarg);
 136                                 if(port < 1)
 137                                         die("Port numbers are > 1\n");
 138                                 break;
 139                         case 'h':
 140                                 usage(stdout, argv[0]);
 141                                 exit(EXIT_SUCCESS);
 142                         default:
 143                                 usage(stderr, argv[0]);
 144                                 exit(EXIT_FAILURE);
 145                 }
 146
 147         }
 148
 149         open_filedescriptors();
 150
 151         long cyclestart;
 152         struct task *curtask;
 153         while(true){
 154                 //Check for new tasks
 155                 if(input_available(fd))
 156                         read_message(fd, fd);
 157                 //Run tasks
 158                 cyclestart = millis();
 159                 for(ct = 0; ct<MAXTASKS; ct++){
 160                         //See whether the task is even in use
 161                         if((curtask = task_get(ct)) == NULL){
 162                                 debug("Task %d not implemented\n", ct);
 163                                 continue;
 164                         }
 165                         //See whether the task interval has passed
 166                         if(cyclestart-curtask->lastrun < curtask->interval){
 167                                 debug("Task %d not scheduled\n", ct);
 168                                 continue;
 169                         }
 170 #ifdef DEBUG
 171                         printf("Current task to run: %d\n", ct);
 172                         getchar();
 173 #endif
 174                         run_task(curtask);
 175                 }
 176                 usleep(10);
 177         }
 178         return 0;
 179 }