Fix #562: Extension times out prematurely on long language server startup

This change extends the timeout for language server startup to a full
minute and also adds some startup logging to keep track of how long
startup took.

Author: daviwil

src/session.ts

@@ -298,6 +298,8 @@ export class SessionManager {
             // Make sure no old session file exists
             utils.deleteSessionFile();
 
+            this.log.write(`${utils.getTimestampString()} Language server starting...`);
+
             // Launch PowerShell in the integrated terminal
             this.consoleTerminal =
                 vscode.window.createTerminal(
@@ -312,6 +314,8 @@ export class SessionManager {
                 (sessionDetails, error) => {
                     if (sessionDetails) {
                         if (sessionDetails.status === "started") {
+                            this.log.write(`${utils.getTimestampString()} Language server started.`);
+
                             // Write out the session configuration file
                             utils.writeSessionFile(sessionDetails);
 
@@ -332,6 +336,7 @@ export class SessionManager {
                         }
                     }
                     else {
+                        this.log.write(`${utils.getTimestampString()} Language server startup failed.`);
                         this.setSessionFailure("Could not start language service: ", error);
                     }
                 });

src/utils.ts

@@ -91,23 +91,24 @@ export function writeSessionFile(sessionDetails: EditorServicesSessionDetails) {
 
 export function waitForSessionFile(callback: WaitForSessionFileCallback) {
 
-    function innerTryFunc(remainingTries: number) {
+    function innerTryFunc(remainingTries: number, delayMilliseconds: number) {
         if (remainingTries == 0) {
             callback(undefined, "Timed out waiting for session file to appear.");
         }
         else if(!checkIfFileExists(sessionFilePath)) {
             // Wait a bit and try again
-            setTimeout(function() { innerTryFunc(remainingTries - 1); }, 500);
+            setTimeout(
+                function() { innerTryFunc(remainingTries - 1, delayMilliseconds); },
+                delayMilliseconds);
         }
         else {
             // Session file was found, load and return it
             callback(readSessionFile(), undefined);
         }
     }
 
-    // Since the delay is 500ms, 50 tries gives 25 seconds of time
-    // for the session file to appear
-    innerTryFunc(50);
+    // Try once per second for 60 seconds, one full minute
+    innerTryFunc(60, 1000);
 }
 
 export function readSessionFile(): EditorServicesSessionDetails {
@@ -132,4 +133,9 @@ export function checkIfFileExists(filePath: string): boolean {
     catch (e) {
         return false;
     }
-}
+}
+
+export function getTimestampString() {
+    var time = new Date();
+    return `[${time.getHours()}:${time.getMinutes()}:${time.getSeconds()}]`
+}