view wtime.c @ 0:0ce47c784647

Initial commit
author Merten Sach <msach@mailbox.tu-berlin.de>
date Tue, 27 Sep 2011 15:08:02 +0200
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1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
2 /* File: wtime.c */
3 /* Description: a timer that reports the current wall time */
4 /* */
5 /* Author: Wei-keng Liao */
6 /* ECE Department Northwestern University */
7 /* email: wkliao@ece.northwestern.edu */
8 /* Copyright, 2005, Wei-keng Liao */
9 /* */
10 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
12 #include <sys/time.h>
13 #include <stdio.h>
14 #include <stdlib.h>
16 /*
17 * Function: wtime
18 * ---------------
19 * Provides a millisecond-resolution timer for measurement purposes.
20 */
21 double wtime(void)
22 {
23 double now_time;
24 struct timeval etstart;
25 struct timezone tzp;
27 if (gettimeofday(&etstart, &tzp) == -1) {
28 fprintf(stderr, "Timing Error: Could Not Get Current Time\n");
29 exit(EXIT_FAILURE);
30 }
32 now_time = ((double)etstart.tv_sec) + /* in seconds */
33 ((double)etstart.tv_usec) / 1000000.0; /* in microseconds */
34 return now_time;
35 }