ADFA-4314 Make IndexingServiceManager.close() block until services close

lsp/indexing/src/main/kotlin/org/appdevforall/codeonthego/indexing/service/IndexingServiceManager.kt

@@ -7,6 +7,7 @@ import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.cancelChildren
 import kotlinx.coroutines.joinAll
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.withTimeoutOrNull
 import org.slf4j.LoggerFactory
 import java.io.Closeable
@@ -41,8 +42,10 @@ class IndexingServiceManager(
 	/**
 	 * Register an [IndexingService].
 	 *
-	 * Must be called before [onProjectSynced]. Services are initialized
-	 * in registration order.
+	 * Must be called before [onProjectSynced]. Services are initialized in an
+	 * unspecified order (they are held in a [ConcurrentHashMap]), so a service's
+	 * [IndexingService.initialize] must not depend on another service having
+	 * been initialized first.
 	 *
 	 * @throws IllegalStateException if called after initialization.
 	 */
@@ -123,51 +126,57 @@ class IndexingServiceManager(
 	override fun close() {
 		log.info("Shutting down indexing services")
 
+		// Close all services and the registry, and block until they finish.
+		// Callers (e.g. ProjectManagerImpl.destroy()) rely on shutdown being
+		// complete when close() returns -- the Closeable contract -- before they
+		// drop their reference to the manager.
+		//
+		// Services are closed concurrently on Dispatchers.Default (so no ordering
+		// is implied), and each close is bounded by SERVICE_CLOSE_TIMEOUT so a
+		// cooperatively-cancellable service cannot stall teardown indefinitely.
+		// Failures are isolated per service.
+		runBlocking {
+			val serviceJobs = services.values.map { service ->
+				launch(Dispatchers.Default) {
+					withTimeoutOrNull(SERVICE_CLOSE_TIMEOUT) {
+						try {
+							service.close()
+							log.debug("Closed service: {}", service.id)
+						} catch (e: Exception) {
+							if (e is CancellationException) throw e
+							log.error("Failed to close service: {}", service.id, e)
+						}
+					} ?: log.warn(
+						"Indexing service {} failed to close within timeout period: {}ms",
+						service.id, SERVICE_CLOSE_TIMEOUT.inWholeMilliseconds,
+					)
+				}
+			}
 
-		// Close services in reverse registration order
-		val cancellationJobs = services.values.reversed().map { service ->
-			scope.launch(Dispatchers.Default) {
+			val closeRegistryJob = launch(Dispatchers.Default) {
 				withTimeoutOrNull(SERVICE_CLOSE_TIMEOUT) {
 					try {
-						service.close()
-						log.debug("Closed service: {}", service.id)
+						registry.close()
 					} catch (e: Exception) {
 						if (e is CancellationException) throw e
-						log.error("Failed to close service: {}", service.id, e)
+						log.error("Failed to close index registry", e)
 					}
-				} ?: run {
-					log.warn("Indexing service {} failed to close within timeout period: {}ms", service.id, SERVICE_CLOSE_TIMEOUT.inWholeMilliseconds)
-				}
+				} ?: log.warn(
+					"Index registry failed to close within timeout: {}ms",
+					SERVICE_CLOSE_TIMEOUT.inWholeMilliseconds,
+				)
 			}
-		}
 
-		val closeRegistryJob = scope.launch(Dispatchers.Default) {
-			withTimeoutOrNull(SERVICE_CLOSE_TIMEOUT) {
-				try {
-					registry.close()
-				} catch (e: Exception) {
-					if (e is CancellationException) throw e
-					log.error("Failed to close index registry")
-				}
-			} ?: run {
-				log.warn("Index registry failed to close within timeout: {}ms", SERVICE_CLOSE_TIMEOUT.inWholeMilliseconds)
-			}
+			joinAll(*serviceJobs.toTypedArray(), closeRegistryJob)
 		}
 
-		scope.launch {
-			runCatching { joinAll(closeRegistryJob, *cancellationJobs.toTypedArray()) }
-				.onFailure { err ->
-					log.error("Failed to close indexing services", err)
-				}
-
-			// Cancel in-flight work
-			scope.coroutineContext.cancelChildren()
-		}
+		// Cancel any in-flight indexing work still running on the manager scope.
+		scope.coroutineContext.cancelChildren()
 
 		services.clear()
 		initialized = false
 
-		log.info("Indexing services shut down requested")
+		log.info("Indexing services shut down")
 	}
 
 	private suspend fun initializeServices() {