Cleaner server shutdown

src/main/kotlin/ru/dbotthepony/kstarbound/server/IntegratedStarboundServer.kt

@@ -12,11 +12,7 @@ class IntegratedStarboundServer(val client: StarboundClient, root: File) : Starb
 
 	override fun tick0(delta: Double) {
 		if (client.isShutdown) {
-			shutdown()
+			close()
 		}
 	}
-
-	override fun close0() {
-
-	}
 }

src/main/kotlin/ru/dbotthepony/kstarbound/server/ServerConnection.kt

@@ -49,9 +49,12 @@ import ru.dbotthepony.kstarbound.world.SystemWorld
 import ru.dbotthepony.kstarbound.world.SystemWorldLocation
 import ru.dbotthepony.kstarbound.world.UniversePos
 import java.util.UUID
+import java.util.concurrent.CompletableFuture
 import java.util.concurrent.Future
 import java.util.concurrent.TimeUnit
+import java.util.concurrent.TimeoutException
 import java.util.concurrent.atomic.AtomicBoolean
+import java.util.concurrent.locks.ReentrantLock
 import java.util.stream.Collectors
 import kotlin.collections.HashMap
 import kotlin.math.min
@@ -523,6 +526,15 @@ class ServerConnection(val server: StarboundServer, type: ConnectionType) : Conn
 	// set to true so failed connection attempts don't appear in chat
 	private var announcedDisconnect = true
 	private val isDisconnecting = AtomicBoolean()
+	private val disconnectSignal = CompletableFuture<Boolean>()
+
+	fun waitDisconnect(howLong: Long, timeUnit: TimeUnit): Boolean {
+		try {
+			return disconnectSignal.get(howLong, timeUnit)
+		} catch (err: Throwable) {
+			return false
+		}
+	}
 
 	private suspend fun disconnect0(reason: String) {
 		// make server forget shipworld right away
@@ -601,8 +613,11 @@ class ServerConnection(val server: StarboundServer, type: ConnectionType) : Conn
 				channel.flush()
 				channel.close()
 			}
+
+			disconnectSignal.complete(true)
 		} catch (err: Throwable) {
 			LOGGER.error("Exception while disconnecting $this", err)
+			disconnectSignal.complete(false)
 		} finally {
 			// don't leave residue entities in worlds if we encountered an exception
 			tracker?.remove("Disconnect: $reason")
@@ -614,7 +629,9 @@ class ServerConnection(val server: StarboundServer, type: ConnectionType) : Conn
 
 	override fun disconnect(reason: String) {
 		if (isDisconnecting.compareAndSet(false, true)) {
-			server.scope.launch { disconnect0(reason) }
+			// launch with global scope because server will pause its own thread
+			// and wait for us to disconnect (if server is shutting down)
+			Starbound.GLOBAL_SCOPE.launch { disconnect0(reason) }
 		}
 	}
 

src/main/kotlin/ru/dbotthepony/kstarbound/server/StarboundServer.kt

@@ -467,8 +467,10 @@ sealed class StarboundServer(val root: File) : BlockableEventLoop("Server thread
 	}
 
 	fun notifyWorldUnloaded(worldID: WorldID) {
-		execute {
+		if (!isShutdown) {
-			worlds.remove(worldID)
+			execute {
+				worlds.remove(worldID)
+			}
 		}
 	}
 
@@ -516,7 +518,11 @@ sealed class StarboundServer(val root: File) : BlockableEventLoop("Server thread
 		return channels.connections.firstOrNull { it.uuid == uuid }
 	}
 
-	protected abstract fun close0()
+	protected open fun close() {
+		channels.close()
+		shutdown()
+	}
+
 	protected abstract fun tick0(delta: Double)
 
 	private fun tick(delta: Double) {
@@ -560,7 +566,6 @@ sealed class StarboundServer(val root: File) : BlockableEventLoop("Server thread
 		database.commit()
 		databaseCleanable.clean()
 		universe.close()
-		close0()
 	}
 
 	companion object {

src/main/kotlin/ru/dbotthepony/kstarbound/server/world/ServerWorld.kt

@@ -207,8 +207,10 @@ class ServerWorld private constructor(
 
 			clients.forEach {
 				LOGGER.info("Kicking ${it.client.alias()} off dying world")
-				it.remove("World shutting down", setReturnWarp = false)
+				it.remove("World shutting down", setReturnWarp = !uncleanShutdown)
-				it.client.enqueueWarp(WarpAlias.Return)
+
+				if (!server.isShutdown)
+					it.client.enqueueWarp(WarpAlias.Return)
 			}
 
 			if (!uncleanShutdown) {