util.c

   1 /*
   2   Parallel Programming - 2026/2027
   3
   4   Utility functions
   5 */
   6
   7 #include <stdio.h>
   8 #include <stdarg.h>
   9 #include <stdlib.h>
  10 #include <time.h>
  11
  12 // controls the output of debugging messages, set to 1 to have no
  13 // messages
  14 int QUIET = 0;
  15
  16
  17 // returns a random integer in [A,B]
  18 int rand_ab(int a, int b)
  19 {
  20   return a + rand() % (b - a + 1);
  21 }
  22
  23 // sleep between MIN and MAX ms
  24 void rand_sleep(int min, int max)
  25 {
  26   int ms = rand_ab(min, max);
  27   struct timespec ts = { ms / 1000, (ms % 1000) * 1000 };
  28
  29   nanosleep(&ts, NULL);
  30 }
  31
  32 // output a debugging message to stderr
  33 void trace(char *format, ...)
  34 {
  35   va_list args;
  36
  37   if (QUIET)
  38     return;
  39
  40   va_start (args, format);
  41   vfprintf(stderr, format, args);
  42   va_end (args);
  43 }
  44
  45 // unconditionally output a message to stderr
  46 void warn(char *format, ...)
  47 {
  48   va_list args;
  49
  50   va_start (args, format);
  51   vfprintf(stderr, format, args);
  52   va_end (args);
  53 }