Fix MockNetwork non-daemon thread leak. (#2397)

testing/node-driver/src/integration-test/kotlin/net/corda/testing/node/MockNetworkIntegrationTests.kt

@@ -0,0 +1,26 @@
+package net.corda.testing.node
+
+import net.corda.core.internal.div
+import net.corda.testing.common.internal.ProjectStructure.projectRootDir
+import net.corda.testing.node.internal.ProcessUtilities.startJavaProcess
+import org.junit.Test
+import kotlin.test.assertEquals
+
+class MockNetworkIntegrationTests {
+    companion object {
+        @JvmStatic
+        fun main(args: Array<String>) {
+            MockNetwork(emptyList()).run {
+                repeat(2) { createNode() }
+                runNetwork()
+                stopNodes()
+            }
+        }
+    }
+
+    @Test
+    fun `does not leak non-daemon threads`() {
+        val quasar = projectRootDir / "lib" / "quasar.jar"
+        assertEquals(0, startJavaProcess<MockNetworkIntegrationTests>(emptyList(), extraJvmArguments = listOf("-javaagent:$quasar")).waitFor())
+    }
+}

testing/node-driver/src/main/kotlin/net/corda/testing/node/InMemoryMessagingNetwork.kt

@@ -161,6 +161,7 @@ class InMemoryMessagingNetwork internal constructor(
 
         handleEndpointMap.clear()
         messageReceiveQueues.clear()
+        timer.cancel()
     }
 
     @CordaSerializable

testing/node-driver/src/main/kotlin/net/corda/testing/node/internal/ProcessUtilities.kt

@@ -8,9 +8,10 @@ import java.nio.file.Path
 object ProcessUtilities {
     inline fun <reified C : Any> startJavaProcess(
             arguments: List<String>,
-            jdwpPort: Int? = null
+            jdwpPort: Int? = null,
+            extraJvmArguments: List<String> = emptyList()
     ): Process {
-        return startJavaProcessImpl(C::class.java.name, arguments, defaultClassPath, jdwpPort, emptyList(), null, null, null)
+        return startJavaProcessImpl(C::class.java.name, arguments, defaultClassPath, jdwpPort, extraJvmArguments, null, null, null)
     }
 
     fun startCordaProcess(