GUI project does not receive suggestion database (#9634)

close #9558

the `InvalidateModulesIndexCommand` may be waiting for the execution lock, while the handler times out.

engine/language-server/src/main/scala/org/enso/languageserver/search/SuggestionsHandler.scala

@@ -92,8 +92,6 @@ final class SuggestionsHandler(
   import context.dispatcher
   import SuggestionsHandler._
 
-  private val timeout = config.executionContext.requestTimeout
-
   override def preStart(): Unit = {
     logger.info(
       "Starting suggestions handler from [{}, {}].",
@@ -357,7 +355,6 @@ final class SuggestionsHandler(
       val handler = context.system.actorOf(
         InvalidateModulesIndexHandler.props(
           RuntimeFailureMapper(contentRootManager),
-          timeout,
           runtimeConnector,
           self
         )
@@ -454,7 +451,6 @@ final class SuggestionsHandler(
       val handler = context.system.actorOf(
         InvalidateModulesIndexHandler.props(
           runtimeFailureMapper,
-          timeout,
           runtimeConnector,
           self
         )

engine/language-server/src/main/scala/org/enso/languageserver/search/handler/InvalidateModulesIndexHandler.scala

@@ -10,20 +10,20 @@ import org.enso.languageserver.util.UnhandledLogging
 import org.enso.polyglot.runtime.Runtime.Api
 
 import java.util.UUID
-import scala.concurrent.duration.FiniteDuration
+import scala.concurrent.duration._
 
 /** A request handler for invalidate modules index command.
   *
   * @param runtimeFailureMapper mapper for runtime failures
-  * @param timeout request timeout
   * @param runtime reference to the runtime connector
   * @param suggestionsHandler reference to the suggestions handler
+  * @param timeout soft request timeout for detecting abnormal behavior
   */
 final class InvalidateModulesIndexHandler(
   runtimeFailureMapper: RuntimeFailureMapper,
-  timeout: FiniteDuration,
   runtime: ActorRef,
-  suggestionsHandler: ActorRef
+  suggestionsHandler: ActorRef,
+  timeout: FiniteDuration
 ) extends Actor
     with LazyLogging
     with UnhandledLogging {
@@ -34,22 +34,30 @@ final class InvalidateModulesIndexHandler(
 
   private def requestStage: Receive = {
     case SearchProtocol.InvalidateModulesIndex =>
-      runtime ! Api.Request(
+      val request = Api.Request(
         UUID.randomUUID(),
         Api.InvalidateModulesIndexRequest()
       )
+      runtime ! request
       val cancellable =
         context.system.scheduler.scheduleOnce(timeout, self, RequestTimeout)
-      context.become(responseStage(sender(), cancellable))
+      context.become(responseStage(sender(), request, cancellable))
   }
 
   private def responseStage(
     replyTo: ActorRef,
+    request: Api.Request,
     cancellable: Cancellable
   ): Receive = {
     case RequestTimeout =>
-      replyTo ! RequestTimeout
-      context.stop(self)
+      logger.warn(
+        "Failed to receive a [{}] response in [{}].",
+        request,
+        timeout
+      )
+      val newCancellable =
+        context.system.scheduler.scheduleOnce(timeout, self, RequestTimeout)
+      context.become(responseStage(replyTo, request, newCancellable))
 
     case Api.Response(_, Api.InvalidateModulesIndexResponse()) =>
       suggestionsHandler ! SearchProtocol.ClearSuggestionsDatabase
@@ -69,22 +77,22 @@ object InvalidateModulesIndexHandler {
   /** Creates a configuration object used to create [[InvalidateModulesIndexHandler]].
     *
     * @param runtimeFailureMapper mapper for runtime failures
-    * @param timeout request timeout
     * @param runtime reference to the runtime connector
     * @param suggestionsHandler reference to the suggestions handler
+    * @param timeout soft request timeout for detecting abnormal behavior
     */
   def props(
     runtimeFailureMapper: RuntimeFailureMapper,
-    timeout: FiniteDuration,
     runtime: ActorRef,
-    suggestionsHandler: ActorRef
+    suggestionsHandler: ActorRef,
+    timeout: FiniteDuration = 30.seconds
   ): Props =
     Props(
       new InvalidateModulesIndexHandler(
         runtimeFailureMapper,
-        timeout,
         runtime,
-        suggestionsHandler
+        suggestionsHandler,
+        timeout
       )
     )
 }