Base class for data communications. More...

#include "Class_Data_LB_Interface.hpp"

Public Member Functions
void	assign (uint32_t stride, uint32_t length)

size_t	fixedSize () const

template<class Buffer >
void	gather (Buffer &buff, const uint32_t e)

void	move (const uint32_t from, const uint32_t to)

void	resize (uint32_t newSize)

void	resizeGhost (uint32_t newSize)

template<class Buffer >
void	scatter (Buffer &buff, const uint32_t e)

void	shrink ()

size_t	size (const uint32_t e) const

Detailed Description

template<class Impl>
class Class_Data_LB_Interface< Impl >

Base class for data communications.

Date: 09/sep/2015

Authors: Edoardo Lombardi; Marco Cisternino

Version: 0.1

Copyright: Copyright 2014 Optimad engineering srl. All rights reserved.

License: This version of PABLO is released under the LGPL License.

This class is the base class used to implement the user interface to data communications for load balance.

The Curiously Recurrent Template Pattern is exploited to achieve the interface. By this way the interface is based on static polymorphism with no extra cost at runtime.

The user has to implement his communication classes for load balance by deriving them from this class. The mechanism implies that the derived class derives from a template base class and that the template parameter is the derived class itself, as follow

class Derived : public Base<Derived>{...}

The user has to implement all the methods of the base class in his derived class. These user's methods will really do the job.

An example of user derived class can be found,here,in test folder for the case of a double datum for each grid element.

Easily speaking, only the user knows his data and through the interface specialization he states the size of element data, how to write/read and move them in a communication buffer.

Definition at line 37 of file Class_Data_LB_Interface.hpp.

Member Function Documentation

template<class Impl >

void Class_Data_LB_Interface< Impl >::assign	(	uint32_t	stride,
		uint32_t	length
	)

inline

Its user specification extracts contiguous element from a data container. This method is used during the very first load balance where the grid from being serial becomes parallel. From the initial serial container, which is the same on every process, this method takes the data relatives to the process sub-domain, storing them in the same resized parallel local container.

Parameters

[in]	stride	The location where the process has to start reading from
[in]	length	The length of the data container the process has to read

Definition at line 32 of file Class_Data_LB_Interface.tpp.

template<class Impl >

size_t Class_Data_LB_Interface< Impl >::fixedSize ( ) const

inline

Its user specification computes the same data size for every element in the grid.

Returns: The size of the data for every element

Definition at line 10 of file Class_Data_LB_Interface.tpp.

template<class Impl >

template<class Buffer >

void Class_Data_LB_Interface< Impl >::gather	(	Buffer &	buff,
		const uint32_t	e
	)

inline

Its user specification writes the e element data to be communicated during the load balance in the buffer.

The user has not to care about the buffer but a char buffer is available in PABLO, Class_Comm_Buffer. This class has an important method, Class_Comm_Buffer::write. This method has to be used to allocate any single element datum in the communication buffer, as follow

buff.write(userdatum)

where userdatum can be any MPI compatible POD variable associated to the e element. In case of a vector of double, called userdata, to store data,

buff.write(userdata[e])

Parameters

[in]	buff	Template communication buffer
[in]	e	The element local index

Definition at line 21 of file Class_Data_LB_Interface.tpp.

template<class Impl >

void Class_Data_LB_Interface< Impl >::move	(	const uint32_t	from,
		const uint32_t	to
	)

inline

Its user specification moves the data from the "from" element to the "to" element

Parameters

[in]	from	Element local index from.
[in]	to	Element local index to.

Definition at line 15 of file Class_Data_LB_Interface.tpp.

template<class Impl >

void Class_Data_LB_Interface< Impl >::resize ( uint32_t newSize )

inline

Its user specification resizes the element data container to the newSize value.

Parameters

[in] newSize The new size of the user data container

Definition at line 37 of file Class_Data_LB_Interface.tpp.

template<class Impl >

void Class_Data_LB_Interface< Impl >::resizeGhost ( uint32_t newSize )

inline

Its user specification resizes the ghost element data container to the newSize value.

Parameters

[in] newSize The new size of the user ghost data container

Definition at line 42 of file Class_Data_LB_Interface.tpp.

template<class Impl >

template<class Buffer >

void Class_Data_LB_Interface< Impl >::scatter	(	Buffer &	buff,
		const uint32_t	e
	)

inline

Its user specification reads the e element data from the communication buffer and store them in the user data container.

The user has not to care about the buffer but a char buffer is available in PABLO, Class_Comm_Buffer. This class has an important method, Class_Comm_Buffer::read(). This method has to be used to read any single element datum from the communication buffer, as follow

buff.read(userdatum)

where userdatum can be any MPI compatible POD variable associated to the e element. In case of a vector of double, called userdata, to store data,

buff.read(userdata[e])

Parameters

[in]	buff	Template communication buffer
[in]	e	The element local index

Definition at line 27 of file Class_Data_LB_Interface.tpp.

template<class Impl >

void Class_Data_LB_Interface< Impl >::shrink ( )

inline

Its user specification reduces the capacity of the container to its size for those containers which has different values for capacity and size. If the user container has no capacity concept, nothing has to be done.

Definition at line 47 of file Class_Data_LB_Interface.tpp.

template<class Impl >

size_t Class_Data_LB_Interface< Impl >::size ( const uint32_t e ) const

inline

Its user specification computes the specific size of data for an element.

Parameters

[in] e The element local index.

Returns: the size of the data for the e element

Definition at line 5 of file Class_Data_LB_Interface.tpp.

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

Public Member Functions

Detailed Description

template<class Impl> class Class_Data_LB_Interface< Impl >

Member Function Documentation

template<class Impl>
class Class_Data_LB_Interface< Impl >