RML: RUNTIME MONITORING LANGUAGE

Luca Franceschini

ACM Student Research Competition

<Programming>, 3 April 2019, Genoa, Italy

A System-Agnostic DSL for Runtime Verification

RUNTIME VERIFICATION 101

Idea: do not verify programs, verify executions

Static analysis on dynamic languages is painful
Some properties are hard to enforce statically
Opportunity to recover (beyond our scope)

Ok, but why?

PROPOSED ARCHITECTURE

RML LANGUAGE

Key ideas:

System-independent
Programmer-friendly syntax
Expressivity (rich set of operators)

EXAMPLE: FILE

open  matches { name: "open"  };
write matches { name: "write" };
close matches { name: "close" };

Main = empty ∨ Something;
Something = open write* close;

EXAMPLE: FILE

open(fd)  matches { name: "open",  args: [fd, ...] };
write(fd) matches { name: "write", args: [fd, ...] };
close(fd) matches { name: "close", args: [fd, ...] };

Main = empty ∨ Something;
Something = { let fd;
    open(fd) write(fd)* close(fd)
};

EXAMPLE: FILES

open(fd)  matches { name: "open",  args: [fd, ...] };
write(fd) matches { name: "write", args: [fd, ...] };
close(fd) matches { name: "close", args: [fd, ...] };

Main = empty ∨ Something;
Something = { let fd;
    open(fd)
    (write(fd)* close(fd)) | Main
};

QUESTIONS?

VERDICT

5-value logic for the verdict:

Error, unexpected event
Ok so far, but more events are expected
Ok, there may be further events
Ok, now termination is expected
Ok, the property is satisfied