Add tests

work1/src/test/kotlin/stack/ConcurrentStackTests.kt

@@ -0,0 +1,50 @@
+package stack
+
+import org.jetbrains.kotlinx.lincheck.annotations.Operation
+import org.jetbrains.kotlinx.lincheck.check
+import org.jetbrains.kotlinx.lincheck.strategy.managed.modelchecking.ModelCheckingOptions
+import org.jetbrains.kotlinx.lincheck.strategy.stress.StressOptions
+import stack.common.ConcurrentStack
+import stack.simple.ConcurrentTreiberStack
+import kotlin.test.Test
+
+abstract class ConcurrentStackTests(private val stack: ConcurrentStack<Int>) {
+    @Operation
+    fun push(value: Int) = stack.push(value)
+
+    @Operation
+    fun pop(): Int? = stack.pop()
+
+    @Operation
+    fun top(): Int? = stack.top()
+
+    @Test
+    fun stressTest() = StressOptions()
+        .sequentialSpecification(SequentialStack::class.java)
+        .check(this::class)
+
+    @Test
+    fun fourThreadsStressTest() = StressOptions()
+        .sequentialSpecification(SequentialStack::class.java)
+        .threads(4)
+        .iterations(50)
+        .invocationsPerIteration(1000)
+        .check(this::class)
+
+    @Test
+    fun modelCheckingTest() = ModelCheckingOptions()
+        .sequentialSpecification(SequentialStack::class.java)
+        .checkObstructionFreedom()
+        .check(this::class)
+
+    @Test
+    fun fourThreadsModelCheckingTest() = ModelCheckingOptions()
+        .sequentialSpecification(SequentialStack::class.java)
+        .checkObstructionFreedom()
+        .threads(4)
+        .iterations(50)
+        .invocationsPerIteration(1000)
+        .check(this::class)
+}
+
+class ConcurrentTreiberStackTests : ConcurrentStackTests(ConcurrentTreiberStack())

work1/src/test/kotlin/stack/SequentialStack.kt

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+package stack
+
+class SequentialStack {
+    private val deque = ArrayDeque<Int>()
+
+    fun push(x: Int) = deque.addLast(x)
+
+    fun pop(): Int? = deque.removeLastOrNull()
+
+    fun top(): Int? = deque.lastOrNull()
+}