From 5ba3b5d13f50af48dd8d12e6dcd2e3150cd1c558 Mon Sep 17 00:00:00 2001
From: Dmitry Bushev <bushevdv@gmail.com>
Date: Thu, 11 Feb 2021 15:44:50 +0300
Subject: [PATCH] Abandon Terminating Language Server (#1463)

Wait for the LS shutdown, spawn the new one,
and only then reply to the client.
---
 .../LanguageServerController.scala              | 17 +++++++++--------
 .../languageserver/LanguageServerRegistry.scala |  8 ++++++++
 .../DefaultDistributionConfiguration.scala      |  9 +++++++--
 3 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/lib/scala/project-manager/src/main/scala/org/enso/projectmanager/infrastructure/languageserver/LanguageServerController.scala b/lib/scala/project-manager/src/main/scala/org/enso/projectmanager/infrastructure/languageserver/LanguageServerController.scala
index d004f41c2156..3a12ab860f62 100644
--- a/lib/scala/project-manager/src/main/scala/org/enso/projectmanager/infrastructure/languageserver/LanguageServerController.scala
+++ b/lib/scala/project-manager/src/main/scala/org/enso/projectmanager/infrastructure/languageserver/LanguageServerController.scala
@@ -221,6 +221,7 @@ class LanguageServerController(
     case ServerDied =>
       log.error(s"Language server died [$connectionInfo]")
       context.stop(self)
+
   }
 
   private def removeClient(
@@ -278,8 +279,9 @@ class LanguageServerController(
       maybeRequester.foreach(_ ! ServerShutdownTimedOut)
       stop()
 
-    case StartServer(_, _, _, _) =>
-      sender() ! PreviousInstanceNotShutDown
+    case m: StartServer =>
+      // This instance has not yet been shut down. Retry
+      context.parent.forward(Retry(m))
   }
 
   private def waitingForChildren(): Receive = { case Terminated(_) =>
@@ -349,18 +351,17 @@ object LanguageServerController {
 
   case object ShutDownServer
 
-  /** Signals boot timeout.
-    */
+  /** Signals boot timeout. */
   case object BootTimeout
 
-  /** Boot command.
-    */
+  /** Boot command. */
   case object Boot
 
-  /** Signals shutdown timeout.
-    */
+  /** Signals shutdown timeout. */
   case object ShutdownTimeout
 
   case object ServerDied
 
+  case class Retry(message: Any)
+
 }
diff --git a/lib/scala/project-manager/src/main/scala/org/enso/projectmanager/infrastructure/languageserver/LanguageServerRegistry.scala b/lib/scala/project-manager/src/main/scala/org/enso/projectmanager/infrastructure/languageserver/LanguageServerRegistry.scala
index a5215ef0b165..d6a42ad8e865 100644
--- a/lib/scala/project-manager/src/main/scala/org/enso/projectmanager/infrastructure/languageserver/LanguageServerRegistry.scala
+++ b/lib/scala/project-manager/src/main/scala/org/enso/projectmanager/infrastructure/languageserver/LanguageServerRegistry.scala
@@ -9,6 +9,7 @@ import org.enso.projectmanager.boot.configuration.{
   SupervisionConfig,
   TimeoutConfig
 }
+import org.enso.projectmanager.infrastructure.languageserver.LanguageServerController.Retry
 import org.enso.projectmanager.infrastructure.languageserver.LanguageServerProtocol.{
   CheckIfServerIsRunning,
   KillThemAll,
@@ -23,6 +24,8 @@ import org.enso.projectmanager.service.LoggingServiceDescriptor
 import org.enso.projectmanager.util.UnhandledLogging
 import org.enso.projectmanager.versionmanagement.DistributionConfiguration
 
+import scala.concurrent.duration._
+
 /** An actor that routes request regarding lang. server lifecycle to the
   * right controller that manages the server.
   * It creates a controller actor, if a server doesn't exist.
@@ -112,6 +115,11 @@ class LanguageServerRegistry(
     case CheckIfServerIsRunning(projectId) =>
       sender() ! serverControllers.contains(projectId)
 
+    case Retry(message) =>
+      context.system.scheduler.scheduleOnce(200.millis, self, message)(
+        context.dispatcher,
+        context.sender()
+      )
   }
 
 }
diff --git a/lib/scala/project-manager/src/main/scala/org/enso/projectmanager/versionmanagement/DefaultDistributionConfiguration.scala b/lib/scala/project-manager/src/main/scala/org/enso/projectmanager/versionmanagement/DefaultDistributionConfiguration.scala
index 0a3083144df9..22dad296113c 100644
--- a/lib/scala/project-manager/src/main/scala/org/enso/projectmanager/versionmanagement/DefaultDistributionConfiguration.scala
+++ b/lib/scala/project-manager/src/main/scala/org/enso/projectmanager/versionmanagement/DefaultDistributionConfiguration.scala
@@ -11,7 +11,10 @@ import org.enso.runtimeversionmanager.distribution.{
   DistributionManager,
   TemporaryDirectoryManager
 }
-import org.enso.runtimeversionmanager.locking.{FileLockManager, ResourceManager}
+import org.enso.runtimeversionmanager.locking.{
+  ResourceManager,
+  ThreadSafeFileLockManager
+}
 import org.enso.runtimeversionmanager.releases.ReleaseProvider
 import org.enso.runtimeversionmanager.releases.engine.{
   EngineRelease,
@@ -38,7 +41,9 @@ object DefaultDistributionConfiguration
   lazy val distributionManager = new DistributionManager(environment)
 
   /** @inheritdoc */
-  lazy val lockManager = new FileLockManager(distributionManager.paths.locks)
+  lazy val lockManager = new ThreadSafeFileLockManager(
+    distributionManager.paths.locks
+  )
 
   /** @inheritdoc */
   lazy val resourceManager = new ResourceManager(lockManager)