Processor event seeder - provides independent pseudo-randomly generated seeds for registered processors on an event by event basis. More...

#include <ProcessorEventSeeder.h>

Public Member Functions
	~ProcessorEventSeeder ()
	Destructor. More...

void	registerProcessor (Processor *proc)
	Called by Processors to register themselves for the seeding service. More...

unsigned int	getSeed (Processor *proc)
	Called by Processors to obtain seed assigned to it for the current event. More...

Private Member Functions
	ProcessorEventSeeder ()
	Constructor. More...

void	refreshSeeds (LCEvent *evt)
	Create new set of seeds for registered Processors for the given event. More...

	ProcessorEventSeeder (const ProcessorEventSeeder &)

ProcessorEventSeeder &	operator= (const ProcessorEventSeeder &)

Private Attributes
int	_global_seed
	Global seed for current Job. More...

bool	_global_seed_set
	Global seed has been set for current Job. More...

bool	_eventProcessingStarted
	bool to ensure no calls of registerProcessor( Processor* proc ) after Event Processesing has started More...

std::vector< std::pair < Processor *, unsigned int > >	_vector_pair_proc_seed
	vector to hold pair of pointers to the registered processors and their assigned seeds More...

Friends
class	ProcessorMgr

Detailed Description

Processor event seeder - provides independent pseudo-randomly generated seeds for registered processors on an event by event basis.

This Class is used to provide individual pseudo-random numbers to Processors on
an event-by-event and run-by-run basis. These may be used by Processors to 
seed their random number generator of choice. In order to use this service 
a Processor must register itself in the init method using:

       Global::EVENTSEEDER->registerProcessor(this);

and should retrieve its allocated event seed during processEvent using:

       int eventSeed = Global::EVENTSEEDER->getSeed(this);

and include the header file:

    #include "marlin/ProcessorEventSeeder.h"            

The global seed is used for a complete job and is set in the Global steering parameters thus:

       <parameter name="RandomSeed" value="1234567890"/>

Note that the value must be a positive integer, with max value 2,147,483,647
A pseudo-random event seed is generated using a three step hashing function of unsigned ints,
in the following order: event_number, run_number, RandomSeed. The hashed int from each step 
in the above order is used as input to the next hash step. This is used to ensure that in 
the likely event of similar values of event_number, run_number and RandomSeed, different 
event seeds will be generated. 

The event seed is then used to seed rand via srand(seed) and then rand is used to 
generate one seed per registered processor.

This mechanism ensures reproducible results for every event, regardless of the sequence 
in which the event is processed in a Marlin job, whilst maintaining the full 32bit range 
for event and run numbers.

If a call is made to getSeed( Processor* ) preceededing a call to registerProcessor( Processor* )
an exception will be thrown.

Author: S.J. Aplin, DESY

Definition at line 57 of file ProcessorEventSeeder.h.

Constructor & Destructor Documentation

marlin::ProcessorEventSeeder::~ProcessorEventSeeder ( )

inline

Destructor.

Definition at line 64 of file ProcessorEventSeeder.h.

marlin::ProcessorEventSeeder::ProcessorEventSeeder ( )

private

Constructor.

Definition at line 14 of file ProcessorEventSeeder.cc.

marlin::ProcessorEventSeeder::ProcessorEventSeeder ( const ProcessorEventSeeder & )

private

Member Function Documentation

unsigned int marlin::ProcessorEventSeeder::getSeed ( Processor * proc )

Called by Processors to obtain seed assigned to it for the current event.

Definition at line 77 of file ProcessorEventSeeder.cc.

References _vector_pair_proc_seed.

ProcessorEventSeeder& marlin::ProcessorEventSeeder::operator= ( const ProcessorEventSeeder & )

private

void marlin::ProcessorEventSeeder::refreshSeeds ( LCEvent * evt )

private

Create new set of seeds for registered Processors for the given event.

This method should only be called from ProcessorMgr::processEvent

Definition at line 46 of file ProcessorEventSeeder.cc.

References _eventProcessingStarted, _global_seed, _vector_pair_proc_seed, std::endl(), and jenkins_hash().

Referenced by marlin::ProcessorMgr::modifyEvent(), and marlin::ProcessorMgr::processEvent().

void marlin::ProcessorEventSeeder::registerProcessor ( Processor * proc )

Called by Processors to register themselves for the seeding service.

Definition at line 19 of file ProcessorEventSeeder.cc.

References _eventProcessingStarted, _global_seed, _global_seed_set, _vector_pair_proc_seed, std::endl(), marlin::StringParameters::getIntVal(), std::make_pair(), marlin::Processor::name(), and marlin::Global::parameters.

Friends And Related Function Documentation

friend class ProcessorMgr

friend

Definition at line 61 of file ProcessorEventSeeder.h.

Member Data Documentation

bool marlin::ProcessorEventSeeder::_eventProcessingStarted

private

bool to ensure no calls of registerProcessor( Processor* proc ) after Event Processesing has started

Definition at line 98 of file ProcessorEventSeeder.h.

Referenced by refreshSeeds(), and registerProcessor().

int marlin::ProcessorEventSeeder::_global_seed

private

Global seed for current Job.

Set in steering file.

Definition at line 89 of file ProcessorEventSeeder.h.

Referenced by refreshSeeds(), and registerProcessor().

bool marlin::ProcessorEventSeeder::_global_seed_set

private

Global seed has been set for current Job.

Definition at line 93 of file ProcessorEventSeeder.h.

Referenced by registerProcessor().

std::vector< std::pair<Processor*, unsigned int> > marlin::ProcessorEventSeeder::_vector_pair_proc_seed

private

vector to hold pair of pointers to the registered processors and their assigned seeds

Definition at line 102 of file ProcessorEventSeeder.h.

Referenced by getSeed(), refreshSeeds(), and registerProcessor().

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

/afs/desy.de/user/d/dudarboh/iLCSoft/Marlin/source/include/marlin/ProcessorEventSeeder.h
/afs/desy.de/user/d/dudarboh/iLCSoft/Marlin/source/src/ProcessorEventSeeder.cc

Public Member Functions

Private Member Functions

Private Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation