CGAL 5.6.1 - Profiling tools, Hash Map, Union-find, Modifiers

#include <CGAL/Timer.h>


The class Timer is a timer class for measuring user process time.

When used to profile a multithreaded algorithm, this timer will add up the process time of each thread, which may be unexpected. To compute the wall-clock time of an algorithm, please consider using CGAL::Real_timer.

A timer t of type Timer is an object with a state. It is either running or it is stopped. The state is controlled with Timer::start() and Timer::stop(). The timer counts the time elapsed since its creation or last reset. It counts only the time where it is in the running state. The time information is given in seconds. The timer counts also the number of intervals it was running, i.e. it counts the number of calls of the Timer::start() member function since the last reset. If the reset occurs while the timer is running it counts as the first interval.


The timer class is based on the C function std::clock() on PC systems and the C function getrusage() on standard POSIX systems. The counter for the std::clock() based solution might wrap around (overflow) after only about 36 minutes. This won't happen on POSIX systems. The system calls to these timers might fail, in which case a warning message will be issued through the CGAL error handler and the functions return with the error codes indicated above. The Timer::precision() method computes the precision dynamically at runtime at its first invocation.


 Timer ()
 state is stopped.


void start ()
void stop ()
void reset ()
 reset timer to zero. More...
bool is_running () const
 true if the current state is running.
double time () const
 user process time in seconds, or 0 if the underlying system call failed.
int intervals () const
 number of start/stop-intervals since the last reset.
double precision () const
 smallest possible time step in seconds, or -1 if the system call failed.
double max () const
 maximal representable time in seconds.

Member Function Documentation

◆ reset()

void CGAL::Timer::reset ( )

reset timer to zero.

The state is unaffected.

◆ start()

void CGAL::Timer::start ( )
state is stopped.

◆ stop()

void CGAL::Timer::stop ( )
state is running.