Protothreads are extremely lightweight stackless threads designed forseverely memory constrained systems such as small embedded systems orsensor network nodes. Protothreads can be used with or without anunderlying operating system.Protothreads provides a blocking context on top of an event-drivensystem, without the overhead of per-thread stacks. The purpose ofprotothreads is to implement sequential flow of control withoutcomplex state machines or full multi-threading.Main features:    * No machine specific code - the protothreads library is pure C    * Does not use error-prone functions such as longjmp()    * Very small RAM overhead - only two bytes per protothread    * Can be used with or without an OS    * Provides blocking wait without full multi-threading or      stack-switching    * Freely available under a BSD-like open source license    Example applications:    * Memory constrained systems    * Event-driven protocol stacks    * Small embedded systems    * Sensor network nodesThe protothreads library is released under an open source BSD-stylelicense that allows for both non-commercial and commercial usage. Theonly requirement is that credit is given.The protothreads library was written by Adam Dunkels <adam@sics.se>with support from Oliver Schmidt <ol.sc@web.de>.More information and new versions can be found at the protothreadshomepage:		     http://www.sics.se/~adam/pt/Documentation can be found in the doc/ subdirectory.Two example programs illustrating the use of protothreads can be foundin this directory:   example-small.c         A small example showing how to use protothreads   example-buffer.c        The bounded buffer problem with protothreads   example-codelock.c	   A code lock with simulated key inputTo compile the examples, simply run "make".Adam Dunkels, 3 June 2006