Wait for ready on raw session start and respect timeout on kernel change

news/2 Fixes/11752.md

@@ -0,0 +1 @@
+When switching to an invalid kernel (one that is registered but cannot start) in raw mode respect the launch timeout that is passed in.

package.nls.json

@@ -494,5 +494,6 @@
     "DataScience.libraryRequiredToLaunchJupyterKernelNotInstalledInterpreter": "{0} requires {1} to be installed.",
     "DataScience.runByLine": "Run by line",
     "DataScience.continueRunByLine": "Stop",
-    "DataScience.couldNotInstallLibrary": "Could not install {0}. If pip is not available, please use the package manager of your choice to manually install this library into your Python environment."
+    "DataScience.couldNotInstallLibrary": "Could not install {0}. If pip is not available, please use the package manager of your choice to manually install this library into your Python environment.",
+    "DataScience.rawKernelSessionFailed": "Unable to start session for kernel {0}. Select another kernel to launch with."
 }

src/client/common/utils/localize.ts

@@ -939,6 +939,10 @@ export namespace DataScience {
     export const kernelStarted = localize('DataScience.kernelStarted', 'Started kernel {0}.');
     export const runByLine = localize('DataScience.runByLine', 'Run by line');
     export const continueRunByLine = localize('DataScience.continueRunByLine', 'Stop');
+    export const rawKernelSessionFailed = localize(
+        'DataScience.rawKernelSessionFailed',
+        'Unable to start session for kernel {0}. Select another kernel to launch with.'
+    );
 }
 
 export namespace DebugConfigStrings {

src/client/datascience/jupyter/kernels/kernelSwitcher.ts

@@ -11,6 +11,7 @@ import { Common, DataScience } from '../../../common/utils/localize';
 import { StopWatch } from '../../../common/utils/stopWatch';
 import { JupyterSessionStartError } from '../../baseJupyterSession';
 import { Commands, Settings } from '../../constants';
+import { RawKernelSessionStartError } from '../../raw-kernel/rawJupyterSession';
 import {
     IJupyterConnection,
     IJupyterKernelSpec,
@@ -125,7 +126,9 @@ export class KernelSwitcher {
             } catch (ex) {
                 if (
                     isLocalConnection &&
-                    (ex instanceof JupyterSessionStartError || ex instanceof JupyterInvalidKernelError)
+                    (ex instanceof JupyterSessionStartError ||
+                        ex instanceof JupyterInvalidKernelError ||
+                        ex instanceof RawKernelSessionStartError)
                 ) {
                     // Looks like we were unable to start a session for the local connection.
                     // Possibly something wrong with the kernel.

src/client/datascience/raw-kernel/rawJupyterSession.ts

@@ -22,6 +22,13 @@ import { ReportableAction } from '../progress/types';
 import { RawSession } from '../raw-kernel/rawSession';
 import { IJupyterKernelSpec, ISessionWithSocket } from '../types';
 
+// Error thrown when we are unable to start a raw kernel session
+export class RawKernelSessionStartError extends Error {
+    constructor(kernelTitle: string) {
+        super(localize.DataScience.rawKernelSessionFailed().format(kernelTitle));
+    }
+}
+
 /*
 RawJupyterSession is the implementation of IJupyterSession that instead of
 connecting to JupyterLab services it instead connects to a kernel directly
@@ -91,7 +98,7 @@ export class RawJupyterSession extends BaseJupyterSession {
             } else if (newSession === null) {
                 sendTelemetryEvent(Telemetry.RawKernelSessionStartTimeout);
                 traceError('Raw session failed to start in given timeout');
-                throw new Error(localize.DataScience.sessionDisposed());
+                throw new RawKernelSessionStartError(kernelSpec.display_name || kernelSpec.name);
             } else {
                 sendTelemetryEvent(Telemetry.RawKernelSessionStartSuccess);
                 traceInfo('Raw session started and connected');
@@ -121,7 +128,7 @@ export class RawJupyterSession extends BaseJupyterSession {
 
     public async createNewKernelSession(
         kernel: IJupyterKernelSpec | LiveKernelModel,
-        _timeoutMS: number,
+        timeoutMS: number,
         interpreter?: PythonInterpreter
     ): Promise<ISessionWithSocket> {
         if (!kernel || 'session' in kernel) {
@@ -131,7 +138,13 @@ export class RawJupyterSession extends BaseJupyterSession {
 
         this.outputChannel.appendLine(localize.DataScience.kernelStarted().format(kernel.display_name || kernel.name));
 
-        return this.startRawSession(kernel, interpreter);
+        const newSession = await waitForPromise(this.startRawSession(kernel, interpreter), timeoutMS);
+
+        if (!newSession) {
+            throw new RawKernelSessionStartError(kernel.display_name || kernel.name);
+        }
+
+        return newSession;
     }
 
     protected shutdownSession(
@@ -209,6 +222,9 @@ export class RawJupyterSession extends BaseJupyterSession {
         // Create our raw session, it will own the process lifetime
         const result = new RawSession(process);
 
+        // When our kernel connects and gets a status message it triggers the ready promise
+        await result.kernel.ready;
+
         // So that we don't have problems with ipywidgets, always register the default ipywidgets comm target.
         // Restart sessions and retries might make this hard to do correctly otherwise.
         result.kernel.registerCommTarget(Identifiers.DefaultCommTarget, noop);