NAME

	spin – verification tool for models of concurrent systems

SYNOPSIS

	spin –a [ –m ] [ –Pcpp ] file spin [ –bglmprsv ] [ –nN ] [ –Pcpp ] file spin –c [ –t ] [ –Pcpp ] file spin –d [ –Pcpp ] file spin –f ltl spin –F file spin –i [ –bglmprsv ] [ –nN ] [ –Pcpp ] file spin –M [ –t ] [ –Pcpp ] file spin –t[N] [ –bglmprsv ] [ –jN ] [ –Pcpp ] file spin –V

DESCRIPTION

Spin is a tool for analyzing the logical consistency of asynchronous systems, specifically distributed software and communication protocols. A verification model of the system is first specified in a guarded command language called Promela. This specification language, described in the reference, allows for the modeling of dynamic creation of asynchronous processes, nondeterministic case selection, loops, gotos, local and global variables. It also allows for a concise specification of logical correctness requirements, including, but not restricted to, requirements expressed in linear temporal logic. Given a Promela model stored in file, spin can perform interactive, guided, or random simulations of the system's execution. It can also generate a C program that performs an exhaustive or approximate verification of the correctness requirements for the system. –a    Generate a verifier (model checker) for the specification. The output is written into a set of C files, named pan.[cbhmt], that can be compiled (pcc pan.c) to produce an executable verifier. The online spin manuals (see below) contain the details on compilation and use of the verifiers. –c    Produce an ASCII approximation of a message sequence chart for a random or guided (when combined with –t) simulation run. See also option –M. –d    Produce symbol table information for the model specified in file. For each Promela object this information includes the type, name and number of elements (if declared as an array), the initial value (if a data object) or size (if a message channel), the scope (global or local), and whether the object is declared as a variable or as a parameter. For message channels, the data types of the message fields are listed. For structure variables, the third field defines the name of the structure declaration that contains the variable. – f ltlTranslate the LTL formula ltl into a never claim. This option reads a formula in LTL syntax from the second argument and translates it into Promela syntax (a never claim, which is Promela's equivalent of a Büchi Automaton). The LTL operators are written: [] (always), <> (eventually), and U (strong until). There is no X (next) operator, to secure compatibility with the partial order reduction rules that are applied during the verification process. If the formula contains spaces, it should be quoted to form a single argument to the spin command. – F file Translate the LTL formula stored in file into a never claim. This behaves identically to option –f but will read the formula from the file instead of from the command line. The file should contain the formula as the first line. Any text that follows this first line is ignored, so it can be used to store comments or annotation on the formula. (On some systems the quoting conventions of the shell complicate the use of option –f. Option –F is meant to solve those problems.) – i    Perform an interactive simulation, prompting the user at every execution step that requires a nondeterministic choice to be made. The simulation proceeds without user intervention when execution is deterministic. –M    Produce a message sequence chart in Postscript form for a random simulation or a guided simulation (when combined with –t), for the model in file, and write the result into file.ps. See also option –c. –m    Changes the semantics of send events. Ordinarily, a send action will be (blocked) if the target message buffer is full. With this option a message sent to a full buffer is lost. –nN   Set the seed for a random simulation to the integer value N. There is no space between the –n and the integer N. –t    Perform a guided simulation, following the error trail that was produces by an earlier verification run, see the online manuals for the details on verification. –V    Prints the spin version number and exits. With only a filename as an argument and no options, spin performs a random simulation of the model specified in the file (standard input is the default if the filename is omitted). If option –i is added, the simulation is interactive, or if option –t is added, the simulation is guided. The simulation normally does not generate output, except what is generated explicitly by the user within the model with printf statements, and some details about the final state that is reached after the simulation completes. The group of options –bglmprsv sets the desired level of information that the user wants about a random, guided, or interactive simulation run. Every line of output normally contains a reference to the source line in the specification that generated it. –b    Suppress the execution of printf statements within the model. –g    Show at each time step the current value of global variables. –l    In combination with option –p, show the current value of local variables of the process. –p    Show at each simulation step which process changed state, and what source statement was executed. –r    Show all message–receive events, giving the name and number of the receiving process and the corresponding the source line number. For each message parameter, show the message type and the message channel number and name. –s    Show all message–send events. –v    Verbose mode, add some more detail, and generate more hints and warnings about the model.

SOURCE

	/sys/src/cmd/spin

SEE ALSO

	http://spinroot.com: GettingStarted.pdf, Roadmap.pdf, Manual.pdf, WhatsNew.pdf, Exercises.pdf G.J. Holzmann, Design and Validation of Computer Protocols, Prentice Hall, 1991. —, `Design and validation of protocols: a tutorial,' Computer Networks and ISDN Systems, Vol. 25, No. 9, 1993, pp. 981–1017. —, `The model checker Spin,' IEEE Trans. on SE, Vol, 23, No. 5, May 1997.