mart/ex07/ex07c.c

   1 #include <stdio.h>
   2 #include <signal.h>
   3 #include <unistd.h>
   4 #include <sys/mman.h>
   5
   6 #include <native/task.h>
   7 #include <native/timer.h>
   8 #include <native/sem.h>
   9
  10 #include  <rtdk.h>
  11 #include <sys/io.h>
  12
  13 #define NTASKS 4
  14
  15 RT_TASK demo_task[NTASKS];
  16 RT_SEM mysync;
  17
  18 // set new baseperiod for the clock :
  19 // - clock only increments counter when a base period is passed
  20 // - the unit of the clock counter is called a jiffie, which in fact
  21 //   represents that a baseperiod is passed
  22 //   e.g. If 10 baseperiods are passed, the clock gives an increase
  23 //   in 10 jiffies
  24 #define BASEPERIOD 1e6   // baseperiod in ns.
  25
  26 // when base period is set, all times in the api are expressed in jiffies
  27 #define EXECTIME   200   // execution time in jiffies
  28 #define SPINTIME    10   // spin time in jiffies
  29
  30 void demo(void *arg)
  31 {
  32         rt_task_set_mode(0, T_RRB, NULL);
  33         RTIME starttime;
  34         RTIME runtime;
  35         int num = *(int *)arg;
  36         RT_TASK *curtask;
  37         RT_TASK_INFO curtaskinfo;
  38
  39         rt_printf("Task: %d\n", num);
  40
  41         rt_sem_p(&mysync, TM_INFINITE);
  42
  43         // let the task run RUNTIME(=200) jiffies in steps of SPINTIME(=20) jiffies
  44         runtime = 0;
  45         while(runtime < EXECTIME) {
  46                 rt_timer_spin(SPINTIME*BASEPERIOD);  // spin cpu doing nothing
  47                 // note: rt_timer_spin function does not accept jiffies only nanoseconds
  48                 //       deviates from timing conventions throughout the Xenomai API
  49
  50                 runtime = runtime + SPINTIME;
  51
  52                 rt_printf("Running Task: %d at time: %d\n", num, runtime);
  53         }
  54         rt_printf("End Task: %d\n", num);
  55 }
  56
  57 //startup code
  58 void startup()
  59 {
  60         int i;
  61         char str[10] ;
  62
  63         // semaphore to sync task startup on
  64         rt_sem_create(&mysync, "MySemaphore", 0, S_FIFO);
  65
  66         // change to period mode because round robin does not work
  67         // in one shot mode
  68         rt_timer_set_mode(BASEPERIOD);// set tick period
  69         for(i = 0; i < NTASKS; i++) {
  70                 rt_printf("start task: %d\n", i);
  71                 sprintf(str, "task%d", i);
  72                 rt_task_create(&demo_task[i], str, 0, i == 3 ? 80 : 50, 0);
  73                 rt_task_slice(&demo_task[i], 1);
  74                 rt_task_start(&demo_task[i], &demo, &i);
  75         }
  76         rt_printf("wake up all tasks\n");
  77         rt_sem_broadcast(&mysync);
  78 }
  79
  80 void init_xenomai() {
  81         /* Avoids memory swapping for this program */
  82         mlockall(MCL_CURRENT | MCL_FUTURE);
  83
  84         /* Perform auto-init of rt_print buffers if the task doesn't do so */
  85         rt_print_auto_init(1);
  86 }
  87
  88 int main(int argc, char* argv[])
  89 {
  90         printf("\nType CTRL-C to end this program\n\n" );
  91
  92         // code to set things to run xenomai
  93         init_xenomai();
  94
  95         //startup code
  96         startup();
  97
  98         // wait for CTRL-c is typed to end the program
  99         pause();
 100 }