Sequential specification

To be sure that the algorithm provides correct sequential behavior, you can define its sequential specification by writing a straightforward sequential implementation of the testing data structure.

tip

This feature also allows you to write a single test instead of two separate sequential and concurrent tests.

To provide a sequential specification of the algorithm for verification:

1. Implement a sequential version of all the testing methods.

2. Pass the class with sequential implementation to the sequentialSpecification() option:

   StressOptions().sequentialSpecification(SequentialQueue::class)

For example, here is the test to check correctness of j.u.c.ConcurrentLinkedQueue from the Java standard library.

import org.jetbrains.kotlinx.lincheck.*
import org.jetbrains.kotlinx.lincheck.annotations.*
import org.jetbrains.kotlinx.lincheck.strategy.stress.*
import org.junit.*
import java.util.*
import java.util.concurrent.*

class ConcurrentLinkedQueueTest {
    private val s = ConcurrentLinkedQueue<Int>()

    @Operation
    fun add(value: Int) = s.add(value)

    @Operation
    fun poll(): Int? = s.poll()

    @Test
    fun stressTest() = StressOptions()
        .sequentialSpecification(SequentialQueue::class.java)
        .check(this::class)
}

class SequentialQueue {
    private val s = LinkedList<Int>()

    fun add(x: Int) = s.add(x)
    fun poll(): Int? = s.poll()
}

note

Get the full code of the examples.