Linux平台多线程下的计时

[C/C++]代码

01 /*************************************************************************
02  * File     :   gettimeofday.c
03  * Author   :   Saurabh Gupta
04  * Desc     :   gettimeofday example c
05  *              gettimeofday example linux
06  *              gettimeofday example
07  *              gettimeofday c
08  *              gettimeofday example code
09  * Source   :   http://saurabhgupta0527.blogspot.com/p/c.html
10  * Created  :   PM 12:12 2 November 2011
11  *************************************************************************/
12
13
14  #include <sys/time.h>
15  #include <stdio.h>
16
17  int main () {
18     struct timeval tim;
19     gettimeofday(&tim, NULL);
20     double t1=tim.tv_sec+(tim.tv_usec/1000000.0);
21     dosomething......
22     gettimeofday(&tim, NULL);
23     double t2=tim.tv_sec+(tim.tv_usec/1000000.0);
24     printf("%.6lf seconds elapsed\n", t2-t1);
25  return 0;
26  }
27
28
29
30 /*
31  * OUTPUT
32  *
33 [sgupta@rhel55x86 time]$ gcc gettimeofday.c -o gettimeofday
34 [sgupta@rhel55x86 time]$ ./gettimeofday
35 0.000000 seconds elapsed
36 [sgupta@rhel55x86 time]$
37  */