system time in milliseconds

[Hopeful22]

I'm try to convert the system date/clock time to milliseconds in order to measure relative completion time of an event. I am sending a tcp connect request from unix A to unix B. I would set T1 on unix A when the request was sent, and set T2 on unix B when request was received.
T2 - T1 = delay_time

Both system times are sync'd via NTP.
Subtraction of [clock click -milliseconds] on both sides yields a negative value. I'm thinking the [clock clicks] is not based on system time but cpu clocks. Both unix boxes are same model.

Any suggestions would be appreciated.
thanks

 

[marsd]

If you are convinced that clock clicks is not what you
could try something like this:

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

int main(void) {
time_t ltime;

time(&ltime);
printf(&quot;%ld\n&quot;, (long)localtime(&ltime));
return 0;
}
Compile and save as systime.
Then:
--------------------------
proc stime {} {
uplevel #0 &quot;set systemtime [exec pathto/systime]&quot;
return
}

 

[Hopeful22]

I was trying out your suggestion. However, I'm receiving compiling errors:

host# gcc systime.c
systime.c: In function `main':
systime.c:7: parse error before `<'
systime.c:8: parse error before `<'

Might I be missing something?

thanks in advance!

 

[marsd]

What platform?

 

[Hopeful22]

I tried to compile it on 2 different systems, but I get the same error.

hostA]# gcc -v
Reading specs from /usr/lib/gcc-lib/i386-redhat-linux/2.96/specs
gcc version 2.96 20000731 (Red Hat Linux 7.1 2.96-98)

hostB# gcc -v
Reading specs from /usr/local/lib/gcc-lib/sparc-sun-solaris2.8/3.2/specs
Configured with: ../configure --with-as=/usr/ccs/bin/as --with-ld=/usr/ccs/bin/ld --disable-nls
Thread model: posix
gcc version 3.2

 

[marsd]

Sorry, the first one wouldn't have returned anything valuable. This program returns microseconds which
are divided by 1000. If this doesn't compile I don't know what to tell you. It compiles fine on:
gcc version 2.95.3 20010315 (SuSE)

#include <stdio.h>
#include <unistd.h>
#include <sys/time.h>



int main(void) {
struct timeval mytime;
struct timezone tz;

if ( (gettimeofday(&mytime,&tz)) != 0) {
perror(&quot;gettimeofday failed&quot;
return 1;
} else {
printf(&quot;Milliseconds: %ld\n&quot;, mytime.tv_usec / 1000);
return 0;
}
return 1;
}

 

[Hopeful22]

That definitely did the trick! It compiled fine.

Thanks a lot marsd!

 

[Hopeful22]

After some further testing, I am getting some negative values sometimes when I do, where stime calls the C program referred in the prior postings:

set START_TIME [stime]
<snip>
...
wait for data
...
<snip>
set END_TIME [stime]

Total time: [expr $END_TIME - $START_TIME]

Any ideas?
Thanks in advance!

 

[marsd]

The turnover is every second.

mars@skag:~/cscraps > stime=`ms`
mars@skag:~/cscraps > etime=`ms`
mars@skag:~/cscraps > echo $stime $etime
Milliseconds: 889 Milliseconds: 654
mars@skag:~/cscraps > stime=`ms`
mars@skag:~/cscraps > etime=`ms`
mars@skag:~/cscraps > echo $stime $etime
Milliseconds: 433 Milliseconds: 949

Can you work with this or do you need milliseconds
measured by the hour, minute, or what???

 

[Hopeful22]

Thanks for your input. It would work better if there's a way to measure the milliseconds by the minute or hour. Reason being it gives no indication on how many turnovers actually occurred.

thanks again

 

[marsd]

I'll work on it.

Seeya.