Scheduler tests improvements

Make stress test faster
Fix OOM in stress test
Public API signatures updated

Author: elizarov

binary-compatibility-validator/reference-public-api/kotlinx-coroutines-core.txt

@@ -143,6 +143,7 @@ public final class kotlinx/coroutines/experimental/CoroutineContextKt {
 public abstract class kotlinx/coroutines/experimental/CoroutineDispatcher : kotlin/coroutines/experimental/AbstractCoroutineContextElement, kotlin/coroutines/experimental/ContinuationInterceptor {
 	public fun <init> ()V
 	public abstract fun dispatch (Lkotlin/coroutines/experimental/CoroutineContext;Ljava/lang/Runnable;)V
+	public fun dispatchYield (Lkotlin/coroutines/experimental/CoroutineContext;Ljava/lang/Runnable;)V
 	public fun interceptContinuation (Lkotlin/coroutines/experimental/Continuation;)Lkotlin/coroutines/experimental/Continuation;
 	public fun isDispatchNeeded (Lkotlin/coroutines/experimental/CoroutineContext;)Z
 	public final fun plus (Lkotlinx/coroutines/experimental/CoroutineDispatcher;)Lkotlinx/coroutines/experimental/CoroutineDispatcher;

binary-compatibility-validator/src/test/kotlin/kotlinx/coroutines/experimental/tools/PublicApiTest.kt

@@ -27,7 +27,9 @@ class PublicApiTest {
 
     @Test
     fun kotlinxCoroutinesCore() {
-        snapshotAPIAndCompare("core/kotlinx-coroutines-core", nonPublicPackages = listOf("kotlinx.coroutines.experimental.internal"))
+        snapshotAPIAndCompare("core/kotlinx-coroutines-core", nonPublicPackages = listOf(
+            "kotlinx.coroutines.experimental.internal",
+            "kotlinx.coroutines.experimental.scheduling"))
     }
 
     @Test

core/kotlinx-coroutines-core/src/test/kotlin/kotlinx/coroutines/experimental/scheduling/CoroutineSchedulerStressTest.kt

@@ -12,7 +12,7 @@ import kotlin.test.*
 class CoroutineSchedulerStressTest : TestBase() {
 
     private var dispatcher: ExperimentalCoroutineDispatcher = ExperimentalCoroutineDispatcher()
-    private val observedThreads = ConcurrentHashMap<Thread, MutableSet<Int>>()
+    private val observedThreads = ConcurrentHashMap<Thread, Long>()
     private val tasksNum = 4_000_000 * stressTestMultiplier
     private val processed = AtomicInteger(0)
     private val finishLatch = CountDownLatch(1)
@@ -53,9 +53,8 @@ class CoroutineSchedulerStressTest : TestBase() {
                         return@Runnable
                     }
 
-                    val defensiveCopy = submittedTasks
                     dispatcher.dispatch(EmptyCoroutineContext, Runnable {
-                        processTask(defensiveCopy)
+                        processTask()
                         processedCounter.incrementAndGet()
                     })
                 }
@@ -83,7 +82,7 @@ class CoroutineSchedulerStressTest : TestBase() {
         submissionInitiator.dispatch(EmptyCoroutineContext, Runnable {
             for (i in 1..tasksNum) {
                 dispatcher.dispatch(EmptyCoroutineContext, Runnable {
-                    processTask(i)
+                    processTask()
                 })
             }
         })
@@ -93,23 +92,18 @@ class CoroutineSchedulerStressTest : TestBase() {
         validateResults()
     }
 
-    private fun processTask(i: Int) {
-        var numbers = observedThreads[Thread.currentThread()]
-        if (numbers == null) {
-            numbers = hashSetOf()
-            observedThreads[Thread.currentThread()] = numbers
-        }
-
-        require(numbers.add(i))
+    private fun processTask() {
+        val counter = observedThreads[Thread.currentThread()] ?: 0L
+        observedThreads[Thread.currentThread()] = counter + 1
 
         if (processed.incrementAndGet() == tasksNum) {
             finishLatch.countDown()
         }
     }
 
     private fun validateResults() {
-        val result = observedThreads.values.flatMap { it }.toSet()
-        assertEquals((1..tasksNum).toSet(), result)
+        val result = observedThreads.values.sum()
+        assertEquals(tasksNum.toLong(), result)
         checkPoolThreadsCreated(Runtime.getRuntime().availableProcessors())
     }
 

core/kotlinx-coroutines-core/src/test/kotlin/kotlinx/coroutines/experimental/scheduling/WorkQueueStressTest.kt

@@ -11,7 +11,7 @@ import kotlin.test.*
 class WorkQueueStressTest : TestBase() {
 
     private val threads = mutableListOf<Thread>()
-    private val offerIterations = 2_000_000 * stressTestMultiplier
+    private val offerIterations = 100_000 * stressTestMultiplier
     private val stealersCount = 6
     private val stolenTasks = Array(stealersCount) { Queue() }
     private val globalQueue = Queue() // only producer will use it