AthRNGSvc Class Reference

A service to manage multiple RNG streams in thread-safe way. More...

#include <AthRNGSvc.h>

Inheritance diagram for AthRNGSvc:

Collaboration diagram for AthRNGSvc:

Public Member Functions
	AthRNGSvc (const std::string &name, ISvcLocator *svc)
	Standard constructor.
virtual	~AthRNGSvc ()
StatusCode	initialize () override final
	Initialize the service.
virtual ATHRNG::RNGWrapper *	getEngine (const INamedInterface *client, const std::string &streamName="") override final
	IAthRNGSvc method to retrieve the random number wrapper.
virtual void	printEngineState (const INamedInterface *client, const std::string &streamName="") override final
	Print engine state.

Private Types
typedef std::function< CLHEP::HepRandomEngine *(void)>	factoryFunc
	Factory function which constructs a HepRandomEngine.

Private Attributes
std::string	m_rngType
	Random number engine type (e.g. dSFMT, ranecu)
std::unordered_map< std::string, ATHRNG::RNGWrapper * >	m_wrappers
	The structure for storing the RNGWrappers.
factoryFunc	m_fact
std::mutex	m_mutex
	Mutex for protecting access to the wrapper structure.

Detailed Description

A service to manage multiple RNG streams in thread-safe way.

The random engines are provided via the RNGWrapper which dereferences to the appropriate slot-local engine.

Todo

Move from manual pointer management to smart pointer management.

Definition at line 33 of file AthRNGSvc.h.

Member Typedef Documentation

factoryFunc

typedef std::function<CLHEP::HepRandomEngine*(void)> AthRNGSvc::factoryFunc

private

Factory function which constructs a HepRandomEngine.

Definition at line 62 of file AthRNGSvc.h.

Constructor & Destructor Documentation

AthRNGSvc()

AthRNGSvc::AthRNGSvc	(	const std::string &	name,
		ISvcLocator *	svc )

Standard constructor.

Definition at line 15 of file AthRNGSvc.cxx.

  : base_class(name, svc),
    m_rngType("dSFMT")
{
  declareProperty("EngineType", m_rngType, "CLHEP RandomEngine type");
}

~AthRNGSvc()

AthRNGSvc::~AthRNGSvc ( )

virtual

Definition at line 97 of file AthRNGSvc.cxx.

{
  // Clean up the RNGWrappers and HepRandomEngines
  for(auto& wrapperPair : m_wrappers) {
    delete wrapperPair.second;
  }
}

Member Function Documentation

getEngine()

ATHRNG::RNGWrapper * AthRNGSvc::getEngine ( const INamedInterface * client, const std::string & streamName = "" )

finaloverridevirtual

IAthRNGSvc method to retrieve the random number wrapper.

Definition at line 49 of file AthRNGSvc.cxx.

{
  // Retrieve number of event slots
  size_t numSlots = SG::getNSlots();
 
  // The name key combines the client name and optional stream name
  std::string rngName = client->name();
  if(!streamName.empty()) rngName += "/" + streamName;
 
  // Look for an existing RNG stream
  std::lock_guard<std::mutex> lock(m_mutex);
  auto it = m_wrappers.find(rngName);
 
  // Construct a new RNGWrapper if none exists
  if(it == m_wrappers.end()){
    ATH_MSG_INFO("Creating engine " << rngName);
    auto wrp = new ATHRNG::RNGWrapper(m_fact, numSlots);
    m_wrappers.insert( std::make_pair(rngName, wrp) );
    return wrp;
  }
 
  ATH_MSG_DEBUG("Returning engine " << rngName);
  return it->second;
}

initialize()

StatusCode AthRNGSvc::initialize ( )

finaloverride

Initialize the service.

Definition at line 22 of file AthRNGSvc.cxx.

{
  if(m_rngType == "dSFMT") {
    m_fact = [](void)->CLHEP::HepRandomEngine*{
      return new CLHEP::dSFMTEngine();
    };
  } else if(m_rngType == "Ranlux64") {
    m_fact = [](void)->CLHEP::HepRandomEngine*{
      return new CLHEP::Ranlux64Engine();
    };
  } else if(m_rngType == "Ranecu") {
    m_fact = [](void)->CLHEP::HepRandomEngine*{
      return new CLHEP::RanecuEngine();
    };
  } else if(m_rngType == "MixMax") {
    m_fact = [](void)->CLHEP::HepRandomEngine*{
      return new CLHEP::MixMaxRng();
    };
  } else {
    ATH_MSG_WARNING("Supported Generator types are 'dSFMT', 'Ranlux64', 'Ranecu', 'MixMax'");
    ATH_MSG_FATAL("Generator type \"" << m_rngType << "\" is not known. Check Joboptions");
    return StatusCode::FAILURE;
  }
  
  return StatusCode::SUCCESS;
}

printEngineState()

void AthRNGSvc::printEngineState ( const INamedInterface * client, const std::string & streamName = "" )

finaloverridevirtual

Print engine state.

Definition at line 75 of file AthRNGSvc.cxx.

{
  // Retrieve the current slot's engine
  ATHRNG::RNGWrapper* wrapper = getEngine(client, streamName);
  CLHEP::HepRandomEngine* engine( *wrapper );
 
  // Extract the engine state numbers
  std::vector<unsigned long> rngStates = engine->put();
 
  // Print the state numbers
  std::string rngName = client->name();
  if(!streamName.empty()) rngName += "/" + streamName;
  std::lock_guard<std::mutex> lock(m_mutex);
  msg(MSG::ALWAYS) << rngName << " ";
  // We mask 32 bits because the other bits are garbage and unused
  for(const unsigned long s : rngStates) {
    msg() << (s & 0xffffffffu) << " ";
  }
  msg() << endmsg;
}

Member Data Documentation

m_fact

factoryFunc AthRNGSvc::m_fact

private

Definition at line 63 of file AthRNGSvc.h.

m_mutex

std::mutex AthRNGSvc::m_mutex

private

Mutex for protecting access to the wrapper structure.

Definition at line 66 of file AthRNGSvc.h.

m_rngType

std::string AthRNGSvc::m_rngType

private

Random number engine type (e.g. dSFMT, ranecu)

Definition at line 56 of file AthRNGSvc.h.

m_wrappers

std::unordered_map<std::string, ATHRNG::RNGWrapper*> AthRNGSvc::m_wrappers

private

The structure for storing the RNGWrappers.

Definition at line 59 of file AthRNGSvc.h.

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The documentation for this class was generated from the following files:

• AthRNGSvc.h
• AthRNGSvc.cxx