mart/ex07/ex07a.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 3
  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         RTIME starttime;
  33         RTIME runtime;
  34         int num = *(int *)arg;
  35         RT_TASK *curtask;
  36         RT_TASK_INFO curtaskinfo;
  37
  38         rt_printf("Task : %d\n", num);
  39
  40         rt_sem_p(&mysync,TM_INFINITE);
  41
  42         // let the task run RUNTIME(=200) jiffies in steps of SPINTIME(=20) jiffies
  43         runtime = 0;
  44         while(runtime < EXECTIME) {
  45                 rt_timer_spin(SPINTIME*BASEPERIOD);  // spin cpu doing nothing
  46                 // note: rt_timer_spin function does not accept jiffies only nanoseconds
  47                 //       deviates from timing conventions throughout the Xenomai API
  48
  49                 runtime += SPINTIME;
  50
  51                 rt_printf("Running Task: %d at time: %d\n", num, runtime);
  52         }
  53         rt_printf("End Task: %d\n", num);
  54 }
  55
  56 //startup code
  57 void startup()
  58 {
  59         int i;
  60         char  str[10] ;
  61
  62         // semaphore to sync task startup on
  63         rt_sem_create(&mysync, "MySemaphore", 0, S_FIFO);
  64
  65         // change to period mode because round robin does not work
  66         // in one shot mode
  67         rt_timer_set_mode(BASEPERIOD);// set tick period
  68         for(i = 0; i < NTASKS; i++) {
  69                 rt_printf("start task: %d\n", i);
  70                 sprintf(str, "task%d", i);
  71                 rt_task_create(&demo_task[i], str, 0, 50, 0);
  72                 rt_task_start(&demo_task[i], &demo, &i);
  73         }
  74         rt_printf("wake up all tasks\n");
  75         rt_sem_broadcast(&mysync);
  76 }
  77
  78 void init_xenomai() {
  79         /* Avoids memory swapping for this program */
  80         mlockall(MCL_CURRENT | MCL_FUTURE);
  81
  82         /* Perform auto-init of rt_print buffers if the task doesn't do so */
  83         rt_print_auto_init(1);
  84 }
  85
  86 int main(int argc, char* argv[])
  87 {
  88         printf("\nType CTRL-C to end this program\n\n" );
  89
  90         // code to set things to run xenomai
  91         init_xenomai();
  92
  93         //startup code
  94         startup();
  95
  96         // wait for CTRL-c is typed to end the program
  97         pause();
  98 }