带有ajax调用的setInterval不会触发成功回调，直到完成另一种表单提交为止

Question

I have an MVC project and I have an asynch action that calls an outside API multiple times in a loop (passing a diff param each time). I'd like to have another ajax call executed on an interval while waiting for this form to submit so the user can see where they're at. I have the following setup but all the "success" callbacks from the secondary calls seem to get paused/put into "pending" status until the first form is done. Can someone tell me what I'm doing wrong?

My first action that calls the main code to loop through the API calls is set up like this:

public async Task<ActionResult> Default(

This process could take a few minutes so I wanted to update the user on which params are being passed. I figured when the form submits which calls the Defauly action, I would do a setInterval with an ajax call to another Controller action and return some json to give back to the user, letting them know the value of a static variable that gets updated during the loop. So at the top of the controller I add

private static string mystatus = "started";

Inside the for loop I update this "mystatus". I added another action

public ActionResult Progress()
{
    dynamic showMessageString = string.Empty;
    showMessageString = new
    {
        param1 = mystatus,
    };
    return Json(showMessageString, JsonRequestBehavior.AllowGet);
}

So I've tried setting the Default action inside both a regular form and Ajax form (Html.Beginform and Html.AjaxForm). I have a button which submits the form. I've tried both SUBMIT types and BUTTON types, manually submitting with the latter. And when the button is clicked, here is the JS code that handles it while the form is submitting

function alertMe() {
    alert("start");
    setInterval(function () {getStatus();}, 3000);
}

function getStatus() {
    $.ajax({
        url: '/Home/Progress',
        dataType: 'json',
        type: 'POST',
        success: function (responseText) {
            alert("test1: " + responseText.param2);
        }
    });
    alert("test2");
    }

    $(document).ready(function () {
        $('#submitme').click(function () {
            alertMe();
        });
    });

In theory, this should hit my Progress action every 3 seconds with an ajax call while my long running form is submitting/grinding away. I put a breakpoint inside my Progress action. What actually happens is this alert("test2"); gets executed every 3 seconds as expected and in the browser developer tools I can see the "Progress" action getting called by the status shows "pending". Then when the long running form is done submitting, THEN my breakpoint gets hit a bunch of times (once for every 3 seconds of processing) and I get bombarded at the end with a bunch of alert("test1: whatever the final status is") a bunch of times in a row.

I tried taking the whole Default form out of this and just kept the button that executed the same JS code (calling this Progress action) and it worked just fine, executing the success callback function every 3 seconds. it's only when there is another form being submitted that the ajax calls seem to "be put on pause" until the first form is done.

Is there a way to make sure these secondary ajax callback functions are executed WHILE the first form is being executed?

Answer 1

Bam!

I added this attribute just above my class name and it started working. [SessionState(System.Web.SessionState.SessionStateBehavior.ReadOnly)]

I guess MS defaults to not letting you run different actions simultaneously in case you change session variables and they get messed up. This simple line takes care of it