dust3d/thirdparty/QuadriFlow/3rd/lemon-1.3.1/lemon/time_measure.h

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/* -*- mode: C++; indent-tabs-mode: nil; -*-
*
* This file is a part of LEMON, a generic C++ optimization library.
*
* Copyright (C) 2003-2013
* Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
* (Egervary Research Group on Combinatorial Optimization, EGRES).
*
* Permission to use, modify and distribute this software is granted
* provided that this copyright notice appears in all copies. For
* precise terms see the accompanying LICENSE file.
*
* This software is provided "AS IS" with no warranty of any kind,
* express or implied, and with no claim as to its suitability for any
* purpose.
*
*/
#ifndef LEMON_TIME_MEASURE_H
#define LEMON_TIME_MEASURE_H
///\ingroup timecount
///\file
///\brief Tools for measuring cpu usage
#ifdef WIN32
#include <lemon/bits/windows.h>
#else
#include <unistd.h>
#include <sys/times.h>
#include <sys/time.h>
#endif
#include <string>
#include <fstream>
#include <iostream>
#include <lemon/math.h>
namespace lemon {
/// \addtogroup timecount
/// @{
/// A class to store (cpu)time instances.
/// This class stores five time values.
/// - a real time
/// - a user cpu time
/// - a system cpu time
/// - a user cpu time of children
/// - a system cpu time of children
///
/// TimeStamp's can be added to or substracted from each other and
/// they can be pushed to a stream.
///
/// In most cases, perhaps the \ref Timer or the \ref TimeReport
/// class is what you want to use instead.
class TimeStamp
{
double utime;
double stime;
double cutime;
double cstime;
double rtime;
public:
///Display format specifier
///\e
///
enum Format {
/// Reports all measured values
NORMAL = 0,
/// Only real time and an error indicator is displayed
SHORT = 1
};
private:
static Format _format;
void _reset() {
utime = stime = cutime = cstime = rtime = 0;
}
public:
///Set output format
///Set output format.
///
///The output format is global for all timestamp instances.
static void format(Format f) { _format = f; }
///Retrieve the current output format
///Retrieve the current output format
///
///The output format is global for all timestamp instances.
static Format format() { return _format; }
///Read the current time values of the process
void stamp()
{
#ifndef WIN32
timeval tv;
gettimeofday(&tv, 0);
rtime=tv.tv_sec+double(tv.tv_usec)/1e6;
tms ts;
double tck=sysconf(_SC_CLK_TCK);
times(&ts);
utime=ts.tms_utime/tck;
stime=ts.tms_stime/tck;
cutime=ts.tms_cutime/tck;
cstime=ts.tms_cstime/tck;
#else
bits::getWinProcTimes(rtime, utime, stime, cutime, cstime);
#endif
}
/// Constructor initializing with zero
TimeStamp()
{ _reset(); }
///Constructor initializing with the current time values of the process
TimeStamp(void *) { stamp();}
///Set every time value to zero
TimeStamp &reset() {_reset();return *this;}
///\e
TimeStamp &operator+=(const TimeStamp &b)
{
utime+=b.utime;
stime+=b.stime;
cutime+=b.cutime;
cstime+=b.cstime;
rtime+=b.rtime;
return *this;
}
///\e
TimeStamp operator+(const TimeStamp &b) const
{
TimeStamp t(*this);
return t+=b;
}
///\e
TimeStamp &operator-=(const TimeStamp &b)
{
utime-=b.utime;
stime-=b.stime;
cutime-=b.cutime;
cstime-=b.cstime;
rtime-=b.rtime;
return *this;
}
///\e
TimeStamp operator-(const TimeStamp &b) const
{
TimeStamp t(*this);
return t-=b;
}
///\e
TimeStamp &operator*=(double b)
{
utime*=b;
stime*=b;
cutime*=b;
cstime*=b;
rtime*=b;
return *this;
}
///\e
TimeStamp operator*(double b) const
{
TimeStamp t(*this);
return t*=b;
}
friend TimeStamp operator*(double b,const TimeStamp &t);
///\e
TimeStamp &operator/=(double b)
{
utime/=b;
stime/=b;
cutime/=b;
cstime/=b;
rtime/=b;
return *this;
}
///\e
TimeStamp operator/(double b) const
{
TimeStamp t(*this);
return t/=b;
}
///The time ellapsed since the last call of stamp()
TimeStamp ellapsed() const
{
TimeStamp t(NULL);
return t-*this;
}
friend std::ostream& operator<<(std::ostream& os,const TimeStamp &t);
///Gives back the user time of the process
double userTime() const
{
return utime;
}
///Gives back the system time of the process
double systemTime() const
{
return stime;
}
///Gives back the user time of the process' children
///\note On <tt>WIN32</tt> platform this value is not calculated.
///
double cUserTime() const
{
return cutime;
}
///Gives back the user time of the process' children
///\note On <tt>WIN32</tt> platform this value is not calculated.
///
double cSystemTime() const
{
return cstime;
}
///Gives back the real time
double realTime() const {return rtime;}
};
inline TimeStamp operator*(double b,const TimeStamp &t)
{
return t*b;
}
///Prints the time counters
///Prints the time counters in the following form:
///
/// <tt>u: XX.XXs s: XX.XXs cu: XX.XXs cs: XX.XXs real: XX.XXs</tt>
///
/// where the values are the
/// \li \c u: user cpu time,
/// \li \c s: system cpu time,
/// \li \c cu: user cpu time of children,
/// \li \c cs: system cpu time of children,
/// \li \c real: real time.
/// \relates TimeStamp
/// \note On <tt>WIN32</tt> platform the cummulative values are not
/// calculated.
inline std::ostream& operator<<(std::ostream& os,const TimeStamp &t)
{
switch(t._format)
{
case TimeStamp::NORMAL:
os << "u: " << t.userTime() <<
"s, s: " << t.systemTime() <<
"s, cu: " << t.cUserTime() <<
"s, cs: " << t.cSystemTime() <<
"s, real: " << t.realTime() << "s";
break;
case TimeStamp::SHORT:
double total = t.userTime()+t.systemTime()+
t.cUserTime()+t.cSystemTime();
os << t.realTime()
<< "s (err: " << round((t.realTime()-total)/
t.realTime()*10000)/100
<< "%)";
break;
}
return os;
}
///Class for measuring the cpu time and real time usage of the process
///Class for measuring the cpu time and real time usage of the process.
///It is quite easy-to-use, here is a short example.
///\code
/// #include<lemon/time_measure.h>
/// #include<iostream>
///
/// int main()
/// {
///
/// ...
///
/// Timer t;
/// doSomething();
/// std::cout << t << '\n';
/// t.restart();
/// doSomethingElse();
/// std::cout << t << '\n';
///
/// ...
///
/// }
///\endcode
///
///The \ref Timer can also be \ref stop() "stopped" and
///\ref start() "started" again, so it is possible to compute collected
///running times.
///
///\warning Depending on the operation system and its actual configuration
///the time counters have a certain (10ms on a typical Linux system)
///granularity.
///Therefore this tool is not appropriate to measure very short times.
///Also, if you start and stop the timer very frequently, it could lead to
///distorted results.
///
///\note If you want to measure the running time of the execution of a certain
///function, consider the usage of \ref TimeReport instead.
///
///\sa TimeReport
class Timer
{
int _running; //Timer is running iff _running>0; (_running>=0 always holds)
TimeStamp start_time; //This is the relativ start-time if the timer
//is _running, the collected _running time otherwise.
void _reset() {if(_running) start_time.stamp(); else start_time.reset();}
public:
///Constructor.
///\param run indicates whether or not the timer starts immediately.
///
Timer(bool run=true) :_running(run) {_reset();}
///\name Control the State of the Timer
///Basically a Timer can be either running or stopped,
///but it provides a bit finer control on the execution.
///The \ref lemon::Timer "Timer" also counts the number of
///\ref lemon::Timer::start() "start()" executions, and it stops
///only after the same amount (or more) \ref lemon::Timer::stop()
///"stop()"s. This can be useful e.g. to compute the running time
///of recursive functions.
///@{
///Reset and stop the time counters
///This function resets and stops the time counters
///\sa restart()
void reset()
{
_running=0;
_reset();
}
///Start the time counters
///This function starts the time counters.
///
///If the timer is started more than ones, it will remain running
///until the same amount of \ref stop() is called.
///\sa stop()
void start()
{
if(_running) _running++;
else {
_running=1;
TimeStamp t;
t.stamp();
start_time=t-start_time;
}
}
///Stop the time counters
///This function stops the time counters. If start() was executed more than
///once, then the same number of stop() execution is necessary the really
///stop the timer.
///
///\sa halt()
///\sa start()
///\sa restart()
///\sa reset()
void stop()
{
if(_running && !--_running) {
TimeStamp t;
t.stamp();
start_time=t-start_time;
}
}
///Halt (i.e stop immediately) the time counters
///This function stops immediately the time counters, i.e. <tt>t.halt()</tt>
///is a faster
///equivalent of the following.
///\code
/// while(t.running()) t.stop()
///\endcode
///
///
///\sa stop()
///\sa restart()
///\sa reset()
void halt()
{
if(_running) {
_running=0;
TimeStamp t;
t.stamp();
start_time=t-start_time;
}
}
///Returns the running state of the timer
///This function returns the number of stop() exections that is
///necessary to really stop the timer.
///For example, the timer
///is running if and only if the return value is \c true
///(i.e. greater than
///zero).
int running() { return _running; }
///Restart the time counters
///This function is a shorthand for
///a reset() and a start() calls.
///
void restart()
{
reset();
start();
}
///@}
///\name Query Functions for the Ellapsed Time
///@{
///Gives back the ellapsed user time of the process
double userTime() const
{
return operator TimeStamp().userTime();
}
///Gives back the ellapsed system time of the process
double systemTime() const
{
return operator TimeStamp().systemTime();
}
///Gives back the ellapsed user time of the process' children
///\note On <tt>WIN32</tt> platform this value is not calculated.
///
double cUserTime() const
{
return operator TimeStamp().cUserTime();
}
///Gives back the ellapsed user time of the process' children
///\note On <tt>WIN32</tt> platform this value is not calculated.
///
double cSystemTime() const
{
return operator TimeStamp().cSystemTime();
}
///Gives back the ellapsed real time
double realTime() const
{
return operator TimeStamp().realTime();
}
///Computes the ellapsed time
///This conversion computes the ellapsed time, therefore you can print
///the ellapsed time like this.
///\code
/// Timer t;
/// doSomething();
/// std::cout << t << '\n';
///\endcode
operator TimeStamp () const
{
TimeStamp t;
t.stamp();
return _running?t-start_time:start_time;
}
///@}
};
///Same as Timer but prints a report on destruction.
///Same as \ref Timer but prints a report on destruction.
///This example shows its usage.
///\code
/// void myAlg(ListGraph &g,int n)
/// {
/// TimeReport tr("Running time of myAlg: ");
/// ... //Here comes the algorithm
/// }
///\endcode
///
///\sa Timer
///\sa NoTimeReport
class TimeReport : public Timer
{
std::string _title;
std::ostream &_os;
bool _active;
public:
///Constructor
///Constructor.
///\param title This text will be printed before the ellapsed time.
///\param os The stream to print the report to.
///\param run Sets whether the timer should start immediately.
///\param active Sets whether the report should actually be printed
/// on destruction.
TimeReport(std::string title,std::ostream &os=std::cerr,bool run=true,
bool active=true)
: Timer(run), _title(title), _os(os), _active(active) {}
///Destructor that prints the ellapsed time
~TimeReport()
{
if(_active) _os << _title << *this << std::endl;
}
///Retrieve the activity status
///\e
///
bool active() const { return _active; }
///Set the activity status
/// This function set whether the time report should actually be printed
/// on destruction.
void active(bool a) { _active=a; }
};
///'Do nothing' version of TimeReport
///\sa TimeReport
///
class NoTimeReport
{
public:
///\e
NoTimeReport(std::string,std::ostream &,bool) {}
///\e
NoTimeReport(std::string,std::ostream &) {}
///\e
NoTimeReport(std::string) {}
///\e Do nothing.
~NoTimeReport() {}
operator TimeStamp () const { return TimeStamp(); }
void reset() {}
void start() {}
void stop() {}
void halt() {}
int running() { return 0; }
void restart() {}
double userTime() const { return 0; }
double systemTime() const { return 0; }
double cUserTime() const { return 0; }
double cSystemTime() const { return 0; }
double realTime() const { return 0; }
};
///Tool to measure the running time more exactly.
///This function calls \c f several times and returns the average
///running time. The number of the executions will be choosen in such a way
///that the full real running time will be roughly between \c min_time
///and <tt>2*min_time</tt>.
///\param f the function object to be measured.
///\param min_time the minimum total running time.
///\retval num if it is not \c NULL, then the actual
/// number of execution of \c f will be written into <tt>*num</tt>.
///\retval full_time if it is not \c NULL, then the actual
/// total running time will be written into <tt>*full_time</tt>.
///\return The average running time of \c f.
template<class F>
TimeStamp runningTimeTest(F f,double min_time=10,unsigned int *num = NULL,
TimeStamp *full_time=NULL)
{
TimeStamp full;
unsigned int total=0;
Timer t;
for(unsigned int tn=1;tn <= 1U<<31 && full.realTime()<=min_time; tn*=2) {
for(;total<tn;total++) f();
full=t;
}
if(num) *num=total;
if(full_time) *full_time=full;
return full/total;
}
/// @}
} //namespace lemon
#endif //LEMON_TIME_MEASURE_H