Add a lincheck test for remove in the segment list algorithm (Kotli…

…n#1964)

gradle.properties

@@ -12,7 +12,7 @@ junit_version=4.12
 atomicfu_version=0.14.2
 knit_version=0.1.3
 html_version=0.6.8
-lincheck_version=2.6
+lincheck_version=2.7.1
 dokka_version=0.9.16-rdev-2-mpp-hacks
 byte_buddy_version=1.10.9
 reactor_vesion=3.2.5.RELEASE

kotlinx-coroutines-core/jvm/test/internal/SegmentBasedQueue.kt

@@ -87,8 +87,24 @@ internal class SegmentBasedQueue<T> {
  }
 
  fun checkHeadPrevIsCleaned() {
- check(head.value.prev === null)
+ check(head.value.prev === null) { "head.prev is not null"}
  }
+
+ fun checkAllSegmentsAreNotLogicallyRemoved() {
+ var prev: OneElementSegment<T>? = null
+ var cur = head.value
+ while (true) {
+ check(!cur.logicallyRemoved || cur.isTail) {
+ "This queue contains removed segments, memory leak detected"
+ }
+ check(cur.prev === prev) {
+ "Two neighbour segments are incorrectly linked: S.next.prev != S"
+ }
+ prev = cur
+ cur = cur.next ?: return
+ }
+ }
+
 }
 
 private fun <T> createSegment(id: Long, prev: OneElementSegment<T>?) = OneElementSegment(id, prev, 0)
@@ -98,9 +114,11 @@ internal class OneElementSegment<T>(id: Long, prev: OneElementSegment<T>?, point
 
  override val maxSlots get() = 1
 
+ val logicallyRemoved get() = element.value === BROKEN
+
  fun removeSegment() {
- element.value = BROKEN
- onSlotCleaned()
+ val old = element.getAndSet(BROKEN)
+ if (old !== BROKEN) onSlotCleaned()
  }
 }
 

kotlinx-coroutines-core/jvm/test/linearizability/SegmentListRemoveLCStressTest.kt

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+@file:Suppress("unused")
+
+package kotlinx.coroutines.linearizability
+
+import kotlinx.coroutines.*
+import kotlinx.coroutines.internal.*
+import org.jetbrains.kotlinx.lincheck.annotations.*
+import org.jetbrains.kotlinx.lincheck.annotations.Operation
+import org.jetbrains.kotlinx.lincheck.paramgen.*
+import org.jetbrains.kotlinx.lincheck.verifier.*
+import org.junit.*
+
+
+class SegmentListRemoveLCStressTest : VerifierState() {
+ private val q = SegmentBasedQueue<Int>()
+ private val segments: Array<OneElementSegment<Int>>
+
+ init {
+ segments = (0..5).map { q.enqueue(it)!! }.toTypedArray()
+ q.enqueue(6)
+ }
+
+ @Operation
+ fun removeSegment(@Param(gen = IntGen::class, conf = "1:5") index: Int) {
+ segments[index].removeSegment()
+ }
+
+ override fun extractState() = segments.map { it.logicallyRemoved }
+
+ @Validate
+ fun checkAllRemoved() {
+ q.checkHeadPrevIsCleaned()
+ q.checkAllSegmentsAreNotLogicallyRemoved()
+ }
+
+ @Test
+ fun test() = LCStressOptionsDefault()
+ .actorsBefore(0)
+ .actorsAfter(0)
+ .check(this::class)
+}