'''Concurrency''' is the concept of simultaneous execution of computational tasks.



** See Also **

   [actor model using coroutines]:   

   [asynchronous methods]:   

   [distributed computation]:   

   [parallel processing]:   

   [http://www-128.ibm.com/developerworks/grid/library/gr-future.html%|%grid services]:   



** Building Blocks **

   [continuation]:   

   [message passing]:   

   [semaphores]:   

   [microthreads]:   

   [How do I manage lock files in a cross platform manner in Tcl%|%lockfiles]:   



** Entities **

In a concurrent system, autonomous or semi-autonomous entities communicate to
achieve the objectives of the system.  Depending on the design, and entity may
be called an '''actor''', '''agent''', '''object''', '''producer''',
'''process''', or '''routine'''.  Here is a list of Tcl facilities and
components that can be used to implement entities.

   [coroutine%|%coroutines]:   

   [generators]:   

   [iterators]:   

   `[interp]`:   Each interpreter serves as an independent routine

   [processes]:   

   [threads]:   



** Models and Paradigms **

   [CSP%|%communicating sequential processes]:   A formal language for describing patterns of interaction in concurrent systems.

   [flow-based programming]:   

   [event-oriented programming%|%event-driven programming]:   



** Systems in Tcl **

The following Tcl systems provision concurrent routines, along with facilities
for communication between them.  See also [message passing] for a list of
systems that only distribute data.


   [csp (package)]:   

   [Daerth]:   Control minions of asynchronous threaded pipelined backpressure-mediated death stations.

   [fiber]:   

   [Gotcl]:   

   [pipethread]:   




** See Also **

   [http://en.wikipedia.org/wiki/Concurrency_(computer_science)%|%Concurrency], Wikipedia:   

   [http://www-106.ibm.com/developerworks/library/l-sc5.html%|%Concurrency for grown-ups] by [CL%|%Cameron Laird], [developerWorks], 2002-08-15:   

   [http://arstechnica.com/paedia/h/hyperthreading/hyperthreading-1.html%|%Introduction to Multithreading, Superthreading and Hyperthreading], by Jon Stokes:   claims to be mostly about (rather specific) hardware, in fact its readability and confident accuracy recommend it for those in search of a more general introduction to operating system-level concurrency.

   [http://www.activestate.com/blog/2010/05/concurrency-tcl-events-without-getting-twisted%|%Concurrency in Tcl: Events without getting Twisted], [Andreas Kupries], 2010-05-06:   

   [http://www.activestate.com/blog/2010/05/concurreny-tcl-weaving-threads%|%Concurreny in Tcl: Weaving Threads], [Andreas Kupries], 2010-05-10:   

   [http://www.activestate.com/blog/2010/06/concurrency-tcl-talking-heads%|%Concurrency in Tcl: Talking Heads], [Andreas Kupries], 2010-06-03:   



** Description **


[Tcl]onians typically focus on maintainability and related development issues.
For a hard-core performance perspective on concurrency, see 
[http://kegel.com/c10k.html%|%The C10K Problem].


<<categories>> Category Concurrency | Category Concept | Category Interprocess Communication