A library for testing concurrent data structures that you lacked!
Lotos aims to provide:
- Simple DSL for specifications
- Configurable generator of test scenarios
- Various consistency model checkers
- Verbose consistency violation reports
Having some implementation of a data structure:
import java.{util => ju}
class UnsafeHashMap extends Serializable {
val underlying = new ju.HashMap[Int, String]
def put(key: Int, value: String): Option[String] = Option(underlying.put(key, value))
def get(key: Int): Option[String] = Option(underlying.get(key))
}describe its specification via Lotos DSL and run the test:
object UnsafeHashMapTest extends IOApp {
val hashMapSpec =
spec(new UnsafeHashMap)
.withMethod(
method("put")
.param("key")(Gen.intGen(1))
.param("value")(Gen.stringGen(1)))
.withMethod(
method("get")
.param("key")(Gen.intGen(1)))
val cfg = TestConfig(parallelism = 2, scenarioLength = 2, scenarioRepetition = 3, scenarioCount = 5)
def run(args: List[String]): IO[ExitCode] =
LotosTest.forSpec(hashMapSpec, cfg, Consistency.sequential) as ExitCode.Success
}In case of failure it will provide a scenario which failed to comply with specified guaranties (e.g. sequential consistency):
Testing scenario 1
Test failed for scenario:
put(key = 0, value = i): None | get(key = 0): None
get(key = 0): Some(i) | put(key = 0, value = t): None
