From: kunst AT prl DOT philips DOT nl (Pieter Kunst)
Subject: usleep() resolution
To: djgpp AT sun DOT soe DOT clarkson DOT edu (DJGPP users list)
Date: Thu, 11 Feb 93 15:55:02 MET
Mailer: Elm [revision: 70.30]


Hello DJ (and J. Alan),

I have found the resolution of the usleep() function of 
one (whole) second a bit too long for some purposes.
A better resolution of 55 milli-seconds can be achieved by 
replacing '$DJGPP/libsrc/c/gen/usleep.c' by the following code.

PS: Why is the prototype for 'clock()' in <std.h> and not in <time.h> ?


Pieter Kunst (kunst AT prl DOT philips DOT nl)



/* This is file usleep.c */
/*
** Copyright (C) 1991 DJ Delorie, 24 Kirsten Ave, Rochester NH 03867-2954
**
** This file is distributed under the terms listed in the document
** "copying.dj", available from DJ Delorie at the address above.
** A copy of "copying.dj" should accompany this file; if not, a copy
** should be available from where this file was obtained.  This file
** may not be distributed without a verbatim copy of "copying.dj".
**
** This file is distributed WITHOUT ANY WARRANTY; without even the implied
** warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*/

#include <time.h>

usleep(unsigned int useconds)
{
  clock_t t0 = clock();

  while (clock() - t0 < useconds) ;
}