src/tests/kits/net/sock/sleepus.c

   1 /* -*- c-basic-offset: 8; -*- */
   2 #include        <sys/types.h>
   3 #include        <sys/time.h>
   4 #include        <errno.h>
   5 #include        <stddef.h>
   6 #include        "ourhdr.h"
   7
   8 void
   9 sleep_us(unsigned int nusecs)
  10 {
  11         struct timeval  tval;
  12
  13         for ( ; ; ) {
  14                 tval.tv_sec = nusecs / 1000000;
  15                 tval.tv_usec = nusecs % 1000000;
  16                 if (select(0, NULL, NULL, NULL, &tval) == 0)
  17                         break;          /* all OK */
  18                 /*
  19                  * Note than on an interrupted system call (i.e, SIGIO) there's not
  20                  * much we can do, since the timeval{} isn't updated with the time
  21                  * remaining.  We could obtain the clock time before the call, and
  22                  * then obtain the clock time here, subtracting them to determine
  23                  * how long select() blocked before it was interrupted, but that
  24                  * seems like too much work :-)
  25                  */
  26                 if (errno == EINTR)
  27                         continue;
  28                 err_sys("sleep_us: select error");
  29         }
  30 }