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Date: Tue, 08 Jan 2008 19:34:55 +0000
From: Greg Chicares <gchicares AT sbcglobal DOT net>
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To: cygwin AT cygwin DOT com
Subject: Re: Does clock() work?
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On 2008-01-08 19:15Z, Norton Allen wrote:
>
> Now, I am definitely interested in wall clock elapsed time. Is there 
> anything available that will give me real time at resolution greater 
> than one second?

/tmp[0]$cat clock_test.c
    #include <time.h>
    #include <unistd.h>
    #include <stdio.h>
    #include <sys/time.h> // gettimeofday()

    int main( int argc, char **argv ) {
      clock_t cur_time, cps = CLOCKS_PER_SEC;
      int i;
      struct timeval x;

      printf( "CLOCKS_PER_SEC = %ld\n", cps );
      for ( i = 0; i < 8; i++ ) {
        sleep(1);
        cur_time = clock();
        printf( "clock() = %ld\n", cur_time );
        gettimeofday(&x, 0);
        printf( "gettimeofday() = %ld\n", 1000000 * x.tv_sec + x.tv_usec );
      }
      return 0;
    }

/tmp[0]$gcc -o clock_test.exe clock_test.c
/tmp[0]$./clock_test
CLOCKS_PER_SEC = 1000
clock() = 30
gettimeofday() = 210033718
clock() = 30
gettimeofday() = 211033718
clock() = 30
gettimeofday() = 212033718
clock() = 30
gettimeofday() = 213033718
clock() = 30
gettimeofday() = 214033718
clock() = 30
gettimeofday() = 215033718
clock() = 30
gettimeofday() = 216033718
clock() = 30
gettimeofday() = 217033718

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