Avoiding a javascript race condition

Question

Here\'s the scenario:

My users are presented a grid, basically, a stripped down version of a spreadsheet. There are textboxes in each row in the grid. When they ch

Answer 1

A semaphore or mutex is probably the best way to go, but instead of a busy loop, just use a setTimeout() to simulate a thread sleep. Like this:

busy = false;

function UserInputChanged(control) {
    busy = true;
    currentControl = control;
    // use setTimeout to simulate slow validation code (production code does not use setTimeout)
    setTimeout("ValidateAmount()", 100); 
}

function SaveForm() {
    if(busy) 
    {
       setTimeout("SaveForm()", 10);
       return;
    }

    // call web service to save value
    document.getElementById("SavedAmount").innerHTML = amount;
}

function ValidateAmount() {
    // various validationey functions here
    amount = currentControl.value; // save value to collection
    document.getElementById("Subtotal").innerHTML = amount; // update subtotals
    busy = false;
}