Re: clock() seems not work !

On Mon, Feb 16, 2004 at 03:13:55PM +0800, Yang wrote:

quoted

On Mon, Feb 16, 2004 at 11:58:07AM +0800, Yang wrote:

quoted

 i am writting applications based ppc+MVL3.0, which i want to get CPU
time,but clock() seems not work for me, for this i did a simple test,as
follows:
/*----------------*/
  while(1)
	{
      printf("current time is ld \n",clock());
	  sleep(1);
	}
/*----------------*/
     But it printed the same value all the while. How is it?

What do you expect from this function?

Did you read manual entry for clock()?

On POSIX systems clock() returns (number of seconds * CLOCKS_PER_SEC)
spent by the process, not a system time/tick count...

Your program is doing _nothing_, so it's normal that clock() returns
the same number. Change sleep(1) to some busy loop and you'll see the
difference.

Eugene.

In fact i want to get a "timeout" utility ,which check periodically if a program has expired.
Based X86

What do you mean under x86?

You aren't talking about Linux x86, are you ?

I'm just curious, what OS are you porting this code from (looks like
DOS to me :) ?

i use clock() to set a timeout and it return the tick count of CPU.
But it's entirely different in Linux. In most my case the timeout is a couple of 10ms.
  The following codes are some fragments in my X86 system, how can i migrate them to Linux?
/*------------------------------------------------*/
 long set_timeout(long timeout)
 {
  return(clock()+timeout/55);  /* i386 tick once per 55ms */
 }

 char chk_timeout(long settime)
 {
   return (clock() >= settime) ? TIMEOUT : NO_TIMEOUT;
 }
/*-------------------------------------------------*/

OK, I think you should check gettimeofday() function.

Eugene.

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