# BSPLib¶

BSPLib is a fast, and easy to use C++ implementation of the Bulk Synchronous Parallel (BSP) threading model. This model is mainly used in the scientific computing field, but can also be applied more general in computer science. This library includes an extended version the standard BSP interface to perform better, and made it more easy to use.

Type Status
Linux & OSX
Windows
Coverage

# BSP¶

The BSP specification can be found here and is maintained by bsp-worldwide.org. Parts of the documentation and code are based off this specification, to ensure backward compatibility between BSP libraries.

# ZPM Installation¶

In .package.json

"requires": [
{
"name": "Zefiros-Software/BSPLib",
"version": "^1.1.0"
}
]


In premake5.lua

zpm.uses "Zefiros-Software/BSPLib"


## Manual Installation¶

The whole library is header only, so for usage in your own code you should clone the repository. And add bsp/include/ as include path. After this you can use the include #include "bsp/bsp.h" in your code to start using the library.

# Code & Documentation¶

The code can be found here. See this for the documentation.

## Features¶

• Fast: All our code is hand optimised using profilers, to ensure maximum performance.
• Reliable: We have an extensive testing suite, making sure we do not break forward and backward compatiblity.
• Easy to use: The library is completely header only. Also next to our improved c++ interface, we shipped the classic BSP C interface.
• Cross platform: Designed to only use C++11, with no external dependencies.
• Warning free, compiled on the highest warning level.

## Usage¶

For detailed usage, please visit BSPLib.

Example

void main( int32_t, const char ** )
{
BSPLib::Execute( []
{
std::cout << "Hello BSP Worldwide from process " << BSPLib::ProcId()
<< " of " << BSPLib::NProcs() << std::endl;
}, BSPLib::NProcs() );
}


### Flexibility¶

#### Don't like the legacy interface?¶

No worries! You can easily disable the macros by defining:

#define BSP_DISABLE_LEGACY


#### Speeding up debugging¶

When debug builds are too slow, you can remove the extra safety check by defining:

#define BSP_SKIP_CHECKS


#### BSPLib Limits¶

• For small programs, you may experience a lot of overhead in starting the threads.
• Starting more threads than available physical cores, may reduce perfomance.
• No support for more nodes by TCP/UDP connections.

## Planned Features¶

• Utility functions, such as broadcasting and various distributions.
• Subset synchronisation on BSPLib::Sync with both predicates and processors lists. eg. BSPLib::Sync( [] { return BSPLib::ProcId() % 2 == 0; } ) and BSPLib::Sync( {1, 3, 4} )
• BenchLib version of BSP bench, so we can circumvent compiler optmisations and differences.

## BSPedupack¶

As an example usage of the BSP programming model we included the BSPedupack written by Rob H. Bisseling with his permission. It includes some tools to benchmark and test the library on different machines, to quote from his own site:

BSPedupack is a library of numerical algorithms written in C according to the BSP model. It uses the BSPlib standard library. The 'edu' in the name stands for educational. The programs are intended for teaching: they give examples of portable parallel numerical programs. The trade-off between clarity/brevity on the one hand, and efficiency on the other hand is in favour of clarity/brevity. There is also an MPI version which teaches how to program in bulk synchronous parallel style using the collective communications from MPI-1 and the one-sided communications from MPI-2. You guessed it, this package is called MPIedupack. Both packages accompany the book: Parallel Scientific Computation: A Structured Approach using BSP and MPI, by Rob H. Bisseling, Oxford University Press, March 2004. ISBN 978-0-19-852939-2.

## Why BSPLib?¶

We wanted an easy to use, high performing BSP model implementation, but of course there were some alternatives.

### BSPLib vs MulticoreBSP¶

• BSPLib is crossplatform, but MulticoreBSP requires POSIX compatibility.
• MulticoreBSP can be compiled with a C compiler.
• MulticoreBSP programs will compile faster.
• BSPLib can disable sanity checks to boost performance.
• BSPLib will only synchronise the used functionality, so we have faster synchronisation.

### BSPLib vs Oxford BSP Toolkit¶

• Oxford BSP Toolkit programs will compile faster.

### BSPLib vs BSPonMPI¶

• BSPLib uses a permissive license (MIT), whereas BSPonMPI uses (LGPL).
• BSPonMPI is based on MPI, so it uses another abstraction layer, whereas BSPLib uses a low level threading interface.
• BSPonMPI programs will compile faster.

## Bugs¶

When a bug is found, please insert it in the issue tracker, so we can resolve it as quickly as we can.

## Contributing¶

1. Fork it!
2. Create your feature branch: git checkout -b my-new-feature
3. Commit your changes: git commit -am 'Add some feature'
4. Push to the branch: git push origin my-new-feature
5. Submit a pull request

## Used By¶

We are interested to find out what projects use BSPLib. We would love to include your projects here, just shoot us a mail. :)

## Citing BSPLib¶

When you use BSPLib as part of a scientific publication, we would love you to cite this project. This BibTex snippet can be used:

@misc{bsplib2016,
author    = {Mick van Duijn and Koen Visscher and Paul Visscher},
title     = {{BSPLib}: a fast, and easy to use {C++} implementation of the {Bulk} {Synchronous} {Parallel} ({BSP}) threading model.},
abstract  = {{BSPLib} is a fast, and easy to use {C++} implementation of the {Bulk} {Synchronous} {Parallel} ({BSP}) threading model. This model is mainly used in the scientific computing field, but can also be applied more general in computer science. This library includes an extended version the standard BSP interface to perform better, and made it more easy to use.},
howpublished = {\url{http://bsplib.eu/}}
}


Copyright (c) 2016 Mick van Duijn, Koen Visscher and Paul Visscher

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