Editing SPIN model checker (section)

==Tool==
Systems to be verified are described in [[Promela]] (Process Meta Language), which supports modeling of [[wikt:asynchronous|asynchronous]] [[distributed algorithm]]s as [[Nondeterministic algorithm|non-deterministic]] [[automata theory|automata]] (''SPIN'' stands for "Simple Promela Interpreter"). Properties to be verified are expressed as [[Linear Temporal Logic|Linear Temporal Logic (LTL)]] formulas, which are negated and then converted into [[Büchi automaton|Büchi automata]] as part of the model-checking algorithm. In addition to model-checking, SPIN can also operate as a simulator, following one possible execution path through the system and presenting the resulting execution trace to the user.

Unlike many model-checkers, SPIN does not actually perform model-checking itself, but instead generates [[C (programming language)|C]] sources for a problem-specific model checker. This technique saves memory and improves performance, while also allowing the direct insertion of chunks of C code into the model. SPIN also offers a large number of options to further speed up the model-checking process and save memory, such as:
*[[partial order reduction]];
*state [[Data compression|compression]];
*[[bitstate hashing]] (instead of storing whole states, only their hash code is remembered in a bitfield; this saves a lot of memory but voids [[Completeness (knowledge bases)|completeness]]);
*weak fairness enforcement.

Since 1995, (approximately) annual SPIN workshops have been held for SPIN users, researchers, and those generally interested in [[model checking]].

In 2001, the [[Association for Computing Machinery]] awarded SPIN its System Software Award.<ref>[https://spinroot.com/gerard/pdf/acm_awarded.pdf Software System Award: ACM CITES TOOL TO DETECT SOFTWARE "BUGS" FOR PRESTIGIOUS AWARD. Bell Labs Researcher Developed "SPIN" to Make Computers More Reliable] // ACM Press-Release</ref>