// before
const cancellationTokenListener = cancellationToken.onCancellationRequested(cancel);
disposable = combinedDisposable(toDisposable(cancel), cancellationTokenListener);

//after
disposable = cancellationToken.onCancellationRequested(cancel);

return result.finally(() => {
	// This will result in the cancel function being executed regardless.
	disposable.dispose();
	this.activeRequests.delete(disposable);
});

const cancel = () => {
	if (uninitializedPromise) {
		uninitializedPromise.cancel();
		uninitializedPromise = null;
	} else {
		// After the client connects, a cancellation request is sent after each request is completed.
		this.sendRequest({ id, type: RequestType.PromiseCancel });
	}
	e(new CancellationError());
};

// server side
finally(() => {
	disposable.dispose();
	// Delete after processing the request.
	this.activeRequests.delete(request.id);
});

// After the server returns the processed request, it receives a cancellation request from the client.
private disposeActiveRequest(request: IRawRequest): void {
	const disposable = this.activeRequests.get(request.id);
	// The request has already been processed and deleted, so the following code will not execute.
	if (disposable) {
		disposable.dispose();
		this.activeRequests.delete(request.id);
	}
}