paradiseo/eo/src/utils/eoTimer.h

357 lines
12 KiB
C++

/*
(c) Thales group, 2012
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation;
version 2 of the License.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Contact: http://eodev.sourceforge.net
Authors:
Benjamin Bouvier <benjamin.bouvier@gmail.com>
*/
# ifndef __EO_TIMER_H__
# define __EO_TIMER_H__
# include <sys/time.h> // gettimeofday()
# include <sys/resource.h> // rusage()
# include <vector> // std::vector
# include <map> // std::map
# include "utils/eoParallel.h" // eo::parallel
# include "serial/eoSerial.h" // eo::Persistent
/**
* @brief Timer allowing to measure time between a start point and a stop point.
*
* This timer allows the user to measure user time, system time and wallclock time
* between two points. Basically, user time is time spent in developer code ; system
* time is time spent during the IO wait and system calls ; wallclock is the difference
* of time we could observe by measuring time with a watch.
*
* @ingroup Utilities
*/
class eoTimer
{
public:
/**
* @brief Default ctor. Begins all the timers.
*/
eoTimer()
{
uuremainder = 0;
usremainder = 0;
restart();
}
/**
* @brief Restarts all the timers and launch the measure.
*/
void restart()
{
gettimeofday( &wc_start, NULL );
getrusage( RUSAGE_SELF, &_start );
}
/**
* @brief Measures the user time spent since the last restart().
*
* If the number of elapsed seconds is zero, the spent milliseconds are
* added to a remainder. If the remainder exceeds one second, it is
* added to the number of elapsed seconds.
*
* @return Number of seconds elapsed in user space.
*/
long int usertime()
{
struct rusage _now;
getrusage( RUSAGE_SELF, &_now );
long int result = _now.ru_utime.tv_sec - _start.ru_utime.tv_sec;
long int remainder = _now.ru_utime.tv_usec - _start.ru_utime.tv_usec;
if( remainder >= 0 )
{
uuremainder += remainder;
} else
{
uuremainder += ( 1000000 - remainder );
--result;
}
if( uuremainder >= 1000000 )
{
uuremainder -= 1000000;
++result;
}
return result;
}
/**
* @brief Measures the system time spent since the last restart().
*
* If the number of elapsed seconds is zero, the spent milliseconds are
* added to a remainder. If the remainder exceeds one second, it is
* added to the number of elapsed seconds.
*
* @return Number of seconds elapsed in system (kernel) space.
*/
long int systime()
{
struct rusage _now;
getrusage( RUSAGE_SELF, &_now );
long int result = _now.ru_stime.tv_sec - _start.ru_stime.tv_sec;
long int remainder = _now.ru_stime.tv_usec - _start.ru_stime.tv_usec;
if( remainder >= 0 )
{
usremainder += remainder;
} else
{
usremainder += ( 1000000 - remainder );
--result;
}
if( usremainder >= 1000000 )
{
usremainder -= 1000000;
++result;
}
return result;
}
/**
* @brief Measures the wallclock time spent since the last restart().
*
* @return Number of seconds elapsed, as a double.
*/
double wallclock()
{
struct timeval wc_end;
gettimeofday( &wc_end, NULL );
return ( wc_end.tv_sec - wc_start.tv_sec ) + ( wc_end.tv_usec - wc_start.tv_usec ) / 1000000.;
}
protected:
// Structure used to measure user and system time.
struct rusage _start;
// Remainder (in milliseconds) for user time.
long int uuremainder;
// Remainder (in milliseconds) for system time.
long int usremainder;
// Structure used to measure wallclock time.
struct timeval wc_start;
};
/**
* @brief Registers a group of statistics, each statistic corresponding to user, system and wallclock times distribution.
*
* This class helps the user to measure time in different parts of an application. A name is associated to a statistic,
* on each call to start() and stop() for this name, a new number is added to the statistic, for each of the three
* measured times.
*
* The statistics are only registered if the option "--parallelized-do-measure" is set to true, which can be checked
* thanks to global object eo::parallel.
*
* This shows how the eoTimerStat can be used :
* @code
* eoTimerStat timerStat;
* timerStat.start("first_point");
* for( int i = 0; i < 1000; ++i )
* {
* timerStat.start("single_computation");
* single_computation( i );
* timerStat.stop("single_computation");
* }
* // After this loop, timerStat contains a statistic of key "single_computation" which contains 1000 measures for
* // each type of time.
* timerStat.stop("first_point");
* // After this line, timerStat contains another statistic of key "first_point" which counted the duration of the
* // whole loop.
*
* int singleComputationUsertimeMean = 0;
* for( int i = 0; i < 1000; ++i )
* {
* singleComputationUsertimeMean += timerStat.stats()["single_computation"].utime[i];
* }
* std::cout << "Mean of user time spent in single computation: " << singleComputationUsertimeMean / 1000. << std::endl;
* @endcode
*
* When using MPI, these statistics can be readily be serialized, so as to be sent over a network, for instance.
*
* Implementation details: this eoTimerStat is in fact a map of strings (key) / Stat (value). Stat is an internal
* structure directly defined in the class, which contains three vectors modeling the distributions of the different
* types of elapsed times. Another map of strings (key) / eoTimer (value) allows to effectively retrieve the different
* times. The struct Stat will be exposed to client, which will use its members ; however,
* the client doesn't have anything to do directly with the timer, that's why the two maps are splitted.
*
* @ingroup Utilities
*/
class eoTimerStat
# ifdef WITH_MPI
: public eoserial::Persistent
# endif
{
public:
/**
* @brief Initializes a timer stat object.
*/
eoTimerStat() : _forceDoMeasure(false)
{
// empty
}
/**
* @brief Statistic related to a key (name).
*
* This structure is the value in the map saved in the eoTimerStat. It contains the statistic bound to a key,
* which are the user time distribution, the system time distribution and the wallclock time distribution, as
* std::vector s.
*
* It can readily be serialized with boost when compiling with mpi.
*/
struct Stat
# ifdef WITH_MPI
: public eoserial::Persistent
# endif
{
std::vector<long int> utime;
std::vector<long int> stime;
std::vector<double> wtime;
#ifdef WITH_MPI
void unpack( const eoserial::Object* obj )
{
utime.clear();
static_cast< eoserial::Array* >(obj->find("utime")->second)
->deserialize< std::vector<long int>, eoserial::Array::UnpackAlgorithm >( utime );
stime.clear();
static_cast< eoserial::Array* >(obj->find("stime")->second)
->deserialize< std::vector<long int>, eoserial::Array::UnpackAlgorithm >( stime );
wtime.clear();
static_cast< eoserial::Array* >(obj->find("wtime")->second)
->deserialize< std::vector<double>, eoserial::Array::UnpackAlgorithm >( wtime );
}
eoserial::Object* pack( void ) const
{
eoserial::Object* obj = new eoserial::Object;
obj->add("utime", eoserial::makeArray< std::vector<long int>, eoserial::MakeAlgorithm >( utime ) );
obj->add("stime", eoserial::makeArray< std::vector<long int>, eoserial::MakeAlgorithm >( stime ) );
obj->add("wtime", eoserial::makeArray< std::vector<double>, eoserial::MakeAlgorithm >( wtime ) );
return obj;
}
# endif
};
#ifdef WITH_MPI
void unpack( const eoserial::Object* obj )
{
_stats.clear();
for( eoserial::Object::const_iterator it = obj->begin(), final = obj->end();
it != final;
++it)
{
eoserial::unpackObject( *obj, it->first, _stats[ it->first ] );
}
}
eoserial::Object* pack( void ) const
{
eoserial::Object* obj = new eoserial::Object;
for( std::map<std::string, Stat >::const_iterator it = _stats.begin(), final = _stats.end();
it != final;
++it)
{
obj->add( it->first, it->second.pack() );
}
return obj;
}
# endif
/**
* @brief Forces the measures to be retrieved.
*/
void forceDoMeasure()
{
_forceDoMeasure = true;
}
/**
* @brief Starts a new measure for the given key.
*
* This is only performed if parallel.doMeasure() is true, which is equivalent to the fact that
* parser found "--parallel-do-measure=1" in command line args.
*
* @param key The key of the statistic.
*/
void start( const std::string & key )
{
if( eo::parallel.doMeasure() or _forceDoMeasure )
{
_timers[ key ].restart();
}
}
/**
* @brief Stops the mesure for the given key and saves the elapsed times.
*
* Must follow a call of start with the same key.
*
* This is only performed if parallel.doMeasure() is true, which is equivalent to the fact that
* parser found "--parallel-do-measure=1" in command line args.
*
* @param key The key of the statistic.
*/
void stop( const std::string& key )
{
if( eo::parallel.doMeasure() or _forceDoMeasure )
{
Stat & s = _stats[ key ];
eoTimer & t = _timers[ key ];
s.utime.push_back( t.usertime() );
s.stime.push_back( t.systime() );
s.wtime.push_back( t.wallclock() );
}
}
/**
* @brief Getter for the statistics map.
*/
std::map< std::string, Stat >& stats()
{
return _stats;
}
/**
* @brief Empties the statistics map.
*/
void clear()
{
_stats.clear();
}
protected:
// Statistics map: links a key (string) to a statistic.
std::map< std::string, Stat > _stats;
// Timers map: links a key to its timer.
std::map< std::string, eoTimer > _timers;
// boolean to force the retrieval of statistics
bool _forceDoMeasure;
};
# endif // __TIMER_H__