计算程序的运行时间,在线等待

[aiwang]

我用VC++做了一个程序,想计算一下他的运行时间,用微秒计算,应该怎么办?

[sevencat]

有个最快的方法是用奔腾的一个指令，好像是
rdtfc(?记不清楚了)，就可以得到开机以来的时间，最精确无比。

[aiwang]

好象有一个涵数可以计算是那一个,我是计算一个程序的运行时间

[JacksonFox]

/* CLOCK.C: This example prompts for how long
* the program is to run and then continuously
* displays the elapsed time for that period.
*/

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

void sleep( clock_t wait );

void main( void )
{
long i = 600000L;
clock_t start, finish;
double duration;

/* Delay for a specified time. */
printf( "Delay for three seconds\n" );
sleep( (clock_t)3 * CLOCKS_PER_SEC );
printf( "Done!\n" );

/* Measure the duration of an event. */
printf( "Time to do %ld empty loops is ", i );
start = clock();
while( i-- )
;
finish = clock();
//下面计算时间
duration = (double)(finish - start) / CLOCKS_PER_SEC;
printf( "%2.1f seconds\n", duration );
}

/* Pauses for a specified number of milliseconds. */
void sleep( clock_t wait )
{
clock_t goal;
goal = wait + clock();
while( goal > clock() )
;
}

运行结果：

Delay for three seconds
Done!
Time to do 600000 empty loops is 0.1 seconds

[qrlvls]

QueryPerformance