edm::ExternalRandomNumberGeneratorService Class Reference

#include <ExternalRandomNumberGeneratorService.h>

Inheritance diagram for edm::ExternalRandomNumberGeneratorService:

Public Member Functions
std::unique_ptr< CLHEP::HepRandomEngine >	cloneEngine (LuminosityBlockIndex const &) final
void	consumes (ConsumesCollector &&iC) const final
	ExternalRandomNumberGeneratorService ()
	ExternalRandomNumberGeneratorService (ExternalRandomNumberGeneratorService const &)=delete
CLHEP::HepRandomEngine &	getEngine (LuminosityBlockIndex const &) final
	Use this engine in the global begin luminosity block method. More...
CLHEP::HepRandomEngine &	getEngine (StreamID const &) final
	Use this engine in event methods. More...
std::vector< RandomEngineState > const &	getEventCache (StreamID const &) const final
std::vector< RandomEngineState > const &	getLumiCache (LuminosityBlockIndex const &) const final
std::vector< unsigned long >	getState () const
std::uint32_t	mySeed () const final
ExternalRandomNumberGeneratorService const &	operator= (ExternalRandomNumberGeneratorService const &)=delete
void	postEventRead (Event const &event) final
void	preBeginLumi (LuminosityBlock const &lumi) final
void	print (std::ostream &os) const final
	For debugging purposes only. More...
void	setEventCache (StreamID, std::vector< RandomEngineState > const &iStates) final
void	setLumiCache (LuminosityBlockIndex, std::vector< RandomEngineState > const &iStates) final
void	setState (std::vector< unsigned long > const &, long seed)
Public Member Functions inherited from edm::RandomNumberGenerator
RandomNumberGenerator const &	operator= (RandomNumberGenerator const &)=delete
	RandomNumberGenerator ()
	RandomNumberGenerator (RandomNumberGenerator const &)=delete
virtual	~RandomNumberGenerator ()

Private Member Functions
std::unique_ptr< CLHEP::HepRandomEngine >	createFromState (std::vector< unsigned long > const &, long seed) const

Private Attributes
std::unique_ptr< CLHEP::HepRandomEngine >	engine_

Detailed Description

Definition at line 20 of file ExternalRandomNumberGeneratorService.h.

Constructor & Destructor Documentation

ExternalRandomNumberGeneratorService() [1/2]

ExternalRandomNumberGeneratorService::ExternalRandomNumberGeneratorService

(

)

Definition at line 22 of file ExternalRandomNumberGeneratorService.cc.

{}

ExternalRandomNumberGeneratorService() [2/2]

edm::ExternalRandomNumberGeneratorService::ExternalRandomNumberGeneratorService ( ExternalRandomNumberGeneratorService const &  )

delete

Member Function Documentation

cloneEngine()

std::unique_ptr< CLHEP::HepRandomEngine > ExternalRandomNumberGeneratorService::cloneEngine ( LuminosityBlockIndex const &  )

finalvirtual

This function is not intended for general use. It is intended for the special case where multiple instances of Pythia 8 will be run concurrently and we want them to be initialized exactly the same. In this special case, the luminosity block engine(s) owned by the service should not be used to generate random numbers in between calls to cloneEngine, because the clone will be in the state that existed at the moment of cloning. Before initializing Pythia, this function should be used to clone the engine owned by the service and the cloned random engine should be used to generate numbers for initialization so that all initializations in the process get identical sequences of random numbers.

Implements edm::RandomNumberGenerator.

Definition at line 39 of file ExternalRandomNumberGeneratorService.cc.

                                                                                                                 {
  std::vector<unsigned long> stateL = engine_->put();
 
  long seedL = engine_->getSeed();
  return createFromState(stateL, seedL);
}

References createFromState(), and engine_.

consumes()

void ExternalRandomNumberGeneratorService::consumes ( ConsumesCollector &&  iC ) const

finalvirtual

Implements edm::RandomNumberGenerator.

Definition at line 88 of file ExternalRandomNumberGeneratorService.cc.

{}

createFromState()

std::unique_ptr< CLHEP::HepRandomEngine > ExternalRandomNumberGeneratorService::createFromState ( std::vector< unsigned long > const &  stateL, long  seed  ) const

private

Definition at line 46 of file ExternalRandomNumberGeneratorService.cc.

                                                              {
  std::unique_ptr<CLHEP::HepRandomEngine> newEngine;
  if (stateL[0] == CLHEP::engineIDulong<CLHEP::HepJamesRandom>()) {
    newEngine = std::make_unique<CLHEP::HepJamesRandom>(seedL);
  } else if (stateL[0] == CLHEP::engineIDulong<CLHEP::RanecuEngine>()) {
    newEngine = std::make_unique<CLHEP::RanecuEngine>();
  } else if (stateL[0] == CLHEP::engineIDulong<CLHEP::MixMaxRng>()) {
    newEngine = std::make_unique<CLHEP::MixMaxRng>(seedL);
    //} else if (stateL[0] == CLHEP::engineIDulong<TRandomAdaptor>()) {
    //  newEngine = std::make_unique<TRandomAdaptor>(seedL);
  } else {
    // Sanity check, it should not be possible for this to happen.
    throw Exception(errors::Unknown)
        << "The ExternalRandomNumberGeneratorService is trying to clone unknown engine type\n";
  }
  if (stateL[0] != CLHEP::engineIDulong<CLHEP::RanecuEngine>()) {
    newEngine->setSeed(seedL, 0);
  }
  newEngine->get(stateL);
  return newEngine;
}

References Exception, and edm::errors::Unknown.

Referenced by cloneEngine(), and setState().

getEngine() [1/2]

CLHEP::HepRandomEngine & ExternalRandomNumberGeneratorService::getEngine ( LuminosityBlockIndex const &  )

finalvirtual

Use this engine in the global begin luminosity block method.

Implements edm::RandomNumberGenerator.

Definition at line 35 of file ExternalRandomNumberGeneratorService.cc.

                                                                                                 {
  return *engine_;
}

References engine_.

getEngine() [2/2]

CLHEP::HepRandomEngine & ExternalRandomNumberGeneratorService::getEngine ( StreamID const &  )

finalvirtual

Use this engine in event methods.

Use the next 2 functions to get the random number engine. These are the only functions most modules should call.

Implements edm::RandomNumberGenerator.

Definition at line 34 of file ExternalRandomNumberGeneratorService.cc.

{ return *engine_; }

References engine_.

getEventCache()

std::vector< RandomEngineState > const & ExternalRandomNumberGeneratorService::getEventCache ( StreamID const &  ) const

finalvirtual

Implements edm::RandomNumberGenerator.

Definition at line 79 of file ExternalRandomNumberGeneratorService.cc.

                                                                                                             {
  return s_dummyStates;
}

getLumiCache()

std::vector< RandomEngineState > const & ExternalRandomNumberGeneratorService::getLumiCache ( LuminosityBlockIndex const &  ) const

finalvirtual

Implements edm::RandomNumberGenerator.

Definition at line 83 of file ExternalRandomNumberGeneratorService.cc.

                                       {
  return s_dummyStates;
}

getState()

std::vector< unsigned long > ExternalRandomNumberGeneratorService::getState

(

)

const

Definition at line 32 of file ExternalRandomNumberGeneratorService.cc.

{ return engine_->put(); }

References engine_.

Referenced by main().

mySeed()

std::uint32_t ExternalRandomNumberGeneratorService::mySeed ( ) const

finalvirtual

This returns the seed from the configuration. In the unusual case where an an engine type takes multiple seeds to initialize a sequence, this function only returns the first. As a general rule, this function should not be used, but is available for backward compatibility and debugging. It might be useful for some types of tests. Using this to seed engines constructed in modules is not recommended because (unless done very carefully) it will create duplicate sequences in different threads and/or data races. Also, if engines are created by modules the replay mechanism will be broken. Because it is dangerous and could be misused, this function might be deleted someday if we ever find time to delete all uses of it in CMSSW. There are of order 10 last time I checked ...

Implements edm::RandomNumberGenerator.

Definition at line 69 of file ExternalRandomNumberGeneratorService.cc.

{ return 0; }

Referenced by main().

operator=()

ExternalRandomNumberGeneratorService const& edm::ExternalRandomNumberGeneratorService::operator= ( ExternalRandomNumberGeneratorService const &  )

delete

postEventRead()

void ExternalRandomNumberGeneratorService::postEventRead ( Event const &  event )

finalvirtual

Implements edm::RandomNumberGenerator.

Definition at line 73 of file ExternalRandomNumberGeneratorService.cc.

{}

preBeginLumi()

void ExternalRandomNumberGeneratorService::preBeginLumi ( LuminosityBlock const &  lumi )

finalvirtual

Implements edm::RandomNumberGenerator.

Definition at line 71 of file ExternalRandomNumberGeneratorService.cc.

{}

print()

void ExternalRandomNumberGeneratorService::print ( std::ostream &  os ) const

finalvirtual

For debugging purposes only.

Implements edm::RandomNumberGenerator.

Definition at line 91 of file ExternalRandomNumberGeneratorService.cc.

{}

setEventCache()

void ExternalRandomNumberGeneratorService::setEventCache ( StreamID  , std::vector< RandomEngineState > const &  iStates  )

finalvirtual

Implements edm::RandomNumberGenerator.

Definition at line 77 of file ExternalRandomNumberGeneratorService.cc.

{}

setLumiCache()

void ExternalRandomNumberGeneratorService::setLumiCache ( LuminosityBlockIndex  , std::vector< RandomEngineState > const &  iStates  )

finalvirtual

Implements edm::RandomNumberGenerator.

Definition at line 75 of file ExternalRandomNumberGeneratorService.cc.

                                                                                                     {}

setState()

void ExternalRandomNumberGeneratorService::setState	(	std::vector< unsigned long > const &	iState,
		long	seed
	)

Definition at line 24 of file ExternalRandomNumberGeneratorService.cc.

                                                                                                      {
  if (not engine_) {
    engine_ = createFromState(iState, iSeed);
  } else {
    engine_->get(iState);
  }
}

References createFromState(), and engine_.

Referenced by main().

Member Data Documentation

engine_

std::unique_ptr<CLHEP::HepRandomEngine> edm::ExternalRandomNumberGeneratorService::engine_

private

Definition at line 57 of file ExternalRandomNumberGeneratorService.h.

Referenced by cloneEngine(), getEngine(), getState(), and setState().