Reduce the overall time spent on stress tests in stress mode (#3890)

* Reduce the number of time spent on lincheck tests in stress mode to be aligned with our stress test multiplier (25) instead of x100
* Reduce the number of iterations and time spent in [nowadays] less relevant tests

Rationale: these contribute to more than an hour of stress tests time spent

Author: qwwdfsad

kotlinx-coroutines-core/concurrent/test/channels/BroadcastChannelSubStressTest.kt

@@ -12,13 +12,13 @@ import kotlin.test.*
  */
 class BroadcastChannelSubStressTest: TestBase() {
 
-    private val nSeconds = 5 * stressTestMultiplier
+    private val nSeconds = maxOf(5, stressTestMultiplier)
     private val sentTotal = atomic(0L)
     private val receivedTotal = atomic(0L)
 
     @Test
     fun testStress() = runTest {
-        TestBroadcastChannelKind.values().forEach { kind ->
+        TestBroadcastChannelKind.entries.forEach { kind ->
             println("--- BroadcastChannelSubStressTest $kind")
             val broadcast = kind.create<Long>()
             val sender =

kotlinx-coroutines-core/concurrent/test/sync/MutexStressTest.kt

@@ -8,7 +8,7 @@ import kotlin.test.*
 
 class MutexStressTest : TestBase() {
 
-    private val n = (if (isNative) 1_000 else 10_000) * stressTestMultiplier
+    private val n = 1000 * stressTestMultiplier // It mostly stresses K/N as JVM Mutex is tested by lincheck
 
     @Test
     fun testDefaultDispatcher() = runTest { testBody(Dispatchers.Default) }

kotlinx-coroutines-core/jvm/test/AbstractLincheckTest.kt

@@ -13,16 +13,16 @@ abstract class AbstractLincheckTest {
 
     @Test
     fun modelCheckingTest() = ModelCheckingOptions()
-        .iterations(if (isStressTest) 200 else 20)
-        .invocationsPerIteration(if (isStressTest) 10_000 else 1_000)
+        .iterations(20 * stressTestMultiplierSqrt)
+        .invocationsPerIteration(1_000 * stressTestMultiplierSqrt)
         .commonConfiguration()
         .customize(isStressTest)
         .check(this::class)
 
     @Test
     fun stressTest() = StressOptions()
-        .iterations(if (isStressTest) 200 else 20)
-        .invocationsPerIteration(if (isStressTest) 10_000 else 1_000)
+        .iterations(20 * stressTestMultiplierSqrt)
+        .invocationsPerIteration(1_000 * stressTestMultiplierSqrt)
         .commonConfiguration()
         .customize(isStressTest)
         .check(this::class)

kotlinx-coroutines-core/jvm/test/channels/BroadcastChannelMultiReceiveStressTest.kt

@@ -15,15 +15,17 @@ import java.util.concurrent.atomic.*
 class BroadcastChannelMultiReceiveStressTest(
     private val kind: TestBroadcastChannelKind
 ) : TestBase() {
+
+    // Stressed by lincheck
     companion object {
         @Parameterized.Parameters(name = "{0}")
         @JvmStatic
         fun params(): Collection<Array<Any>> =
-            TestBroadcastChannelKind.values().map { arrayOf<Any>(it) }
+            TestBroadcastChannelKind.entries.map { arrayOf<Any>(it) }
     }
 
     private val nReceivers = if (isStressTest) 10 else 5
-    private val nSeconds = 3 * stressTestMultiplier
+    private val nSeconds = 3 * stressTestMultiplierSqrt
 
     private val broadcast = kind.create<Long>()
     private val pool = newFixedThreadPoolContext(nReceivers + 1, "BroadcastChannelMultiReceiveStressTest")
@@ -62,13 +64,13 @@ class BroadcastChannelMultiReceiveStressTest(
             println("Launching $name")
             receivers += launch(pool + CoroutineName(name)) {
                 val channel = broadcast.openSubscription()
-                    when (receiverIndex % 5) {
-                        0 -> doReceive(channel, receiverIndex)
-                        1 -> doReceiveCatching(channel, receiverIndex)
-                        2 -> doIterator(channel, receiverIndex)
-                        3 -> doReceiveSelect(channel, receiverIndex)
-                        4 -> doReceiveCatchingSelect(channel, receiverIndex)
-                    }
+                when (receiverIndex % 5) {
+                    0 -> doReceive(channel, receiverIndex)
+                    1 -> doReceiveCatching(channel, receiverIndex)
+                    2 -> doIterator(channel, receiverIndex)
+                    3 -> doReceiveSelect(channel, receiverIndex)
+                    4 -> doReceiveCatchingSelect(channel, receiverIndex)
+                }
                 channel.cancel()
             }
             printProgress()
@@ -93,7 +95,7 @@ class BroadcastChannelMultiReceiveStressTest(
         } catch (e: Exception) {
             println("Failed: $e")
             pool.dumpThreads("Threads in pool")
-            receivers.indices.forEach { index  ->
+            receivers.indices.forEach { index ->
                 println("lastReceived[$index] = ${lastReceived[index].get()}")
             }
             throw e
@@ -116,8 +118,9 @@ class BroadcastChannelMultiReceiveStressTest(
             try {
                 val stop = doReceived(receiverIndex, channel.receive())
                 if (stop) break
+            } catch (ex: ClosedReceiveChannelException) {
+                break
             }
-            catch (ex: ClosedReceiveChannelException) { break }
         }
     }
 
@@ -141,7 +144,9 @@ class BroadcastChannelMultiReceiveStressTest(
                 val event = select<Long> { channel.onReceive { it } }
                 val stop = doReceived(receiverIndex, event)
                 if (stop) break
-            } catch (ex: ClosedReceiveChannelException) { break }
+            } catch (ex: ClosedReceiveChannelException) {
+                break
+            }
         }
     }
 
@@ -152,4 +157,10 @@ class BroadcastChannelMultiReceiveStressTest(
             if (stop) break
         }
     }
+
+    @Suppress("UNUSED_PARAMETER")
+    private fun println(debugMessage: String) {
+        // Uncomment for local debugging
+        //println(debugMessage as Any?)
+    }
 }

kotlinx-coroutines-core/jvm/test/selects/SelectPhilosophersStressTest.kt

@@ -7,7 +7,7 @@ import org.junit.Test
 import kotlin.test.*
 
 class SelectPhilosophersStressTest : TestBase() {
-    private val TEST_DURATION = 3000L * stressTestMultiplier
+    private val TEST_DURATION = 3000L * stressTestMultiplierSqrt
 
     val n = 10 // number of philosophers
     private val forks = Array(n) { Mutex() }
@@ -59,4 +59,4 @@ class SelectPhilosophersStressTest : TestBase() {
             assertTrue(eats > 0, "$id shall not starve")
         }
     }
-}
+}