CSP For Posix Threads

Communicating Sequential Processes is a mathematical algebra for analysing the behaviour of concurrent systems. Because most software systems interact with the real world, they are concurrent to a greater or lesser extent.

libcsp is a library that provides for C programmers a level of abstraction that makes programming with threads much easier. By providing an easy mechanism to express and reason about programs with multiple threads, it becomes easier to fit software into the real world.

In essence, libcsp is a C library that provides the benefits previously known to occam programmers:

• threads communicate by passing messages;
  
  
• when a message is passed between threads, the sender and the receiver have to rendezvous in time - usually this means one thread has to wait for the other;
  
  
• receiver threads can select between alternate channels - called 'alternation' in CSP;
  
  
• as in occam and unlike CSP itself, senders cannot alternate between output sources (this would cause serious implementation problems and is provably not necessary).

So the two most important points are that the concept enables mathematical proofs of correct thread behaviour, and alternation makes for simple system design.

Download:

• Licence (Lesser GPL)
• Latest release (libcsp-2001-06-12.tar.gz) v0.50 beta.
• README.txt release notes.
• CPA2000 Conference Talk slide show (presented at Communicating Process Architectures - 2000)
• Libcsp development resources on Sourceforge.

Further information:

• CSP
  

  http://wotug.ukc.ac.uk/csp.shtml
  http://wotug.ukc.ac.uk/parallel/theory/formal/csp/

• occam
  

  http://wotug.ukc.ac.uk/parallel/occam/
  http://archive.comlab.ox.ac.uk/archive/occam.html