significantly different timer class behaviour on Win and Lin

[skv]

clock() function used in implementation of 
boost::timer behaves differently on Windows (MS XP 
Pro, MSVC 7.1) and Linux (FC3, gcc 3.4.2).

Windows: clock measures elapsed time (wall clock). 
And this comply with boost::timer interface 
description.

Example:
boost::timer t;
double sec = 1;
::Sleep(sec*1000); 
double d = t.elapsed();
assert(abs(d-sec) < 0.1);

Linux: clock() function returnes process CPU time. 
The above code will fail.

This difference makes boost::timer a bad candidate 
for cross-platform development. I can propose 
alternative implementation with simalar right 
behaviour.

------------------------------------------
#ifndef 
_Timer_h_dlfkgh9384ytdflg9045uhy0823475mgd385uyn0v68uy
c0n4c5
#define 
_Timer_h_dlfkgh9384ytdflg9045uhy0823475mgd385uyn0v68uy
c0n4c5

#include <time.h>

namespace Timer
{
	/*
        Measures intervals of wall clock time, but 
not process CPU time. Resolution & accuracy depends 
on time function abilities.
        */
	class timer
	{
	public:
		// setup reference time point
		timer()
		{
			restart();
		}

		// reset reference time point
		void restart()
		{
			::time(&m_ref_time);
		}

		// report difference between current 
time and reference point
		double elapsed() const
		{
			time_t curr_time;
			::time(&curr_time);
			double diff = difftime
(curr_time, m_ref_time);
			return diff;
		}

	// forbidden
	private:
		timer(const timer &);
		timer & operator=(const timer &);

	private:
		time_t m_ref_time;
	};


} // namespace Timer


#endif //_Timer_h_dlfkgh9384ytdflg9045uhy0823475mgd385
uyn0v68uyc0n4c5

[nobody]

Logged In: NO 

A new boost::timer class is under development, it'll be
using the boost::date_time classes for its timing.

You can find current examples on Vault.

Philippe Vaucher

[Marshall Clow]

assigning to actual user "bemandawes" instead of unknown user "beman_dawes"

[Beman Dawes]

This request has been repeated many times. The Boost.System replacement that Philippe spoke of is now (27 Aut 2007) in the boost-sandbox. See boost-root/libs/system/doc/timer.html.

This should be moving into the review queue in the next week or so. I'm closing out the ticket.

Thanks,

--Beman