Synchronous delay in code execution

kavita picture kavita · Aug 3, 2011 · Viewed 58.8k times · Source

I have a code which needs to be executed after some delay say 5000 ms.Currently I am using setTimeout but it is asynchronous and i want the execution to wait for its return. I have tried using the following:

function pauseComp(ms) 
 {
     var curr = new Date().getTime();
     ms += curr;
     while (curr   < ms) {
         curr = new Date().getTime();
     }
 } 

But the code i want to delay is drawing some objects using raphaeljs and the display is not at all smooth. I am trying to use doTimeout plugin. I need to have a delay only once as the delay and code to be delayed are both in a loop. I have no requirement for a id so I am not using it. For example:

for(i; i<5; i++){ $.doTimeout(5000,function(){
         alert('hi');  return false;}, true);}

This waits for 5 sec befor giving first Hi and then successive loop iterations show alert immediately after the first. What I want it to do is wait 5 sec give alert again wait and then give alert and so on.

Any hints/ suggestions are appreciated!

Answer

ThinkBonobo picture ThinkBonobo · Aug 8, 2016

Variation on the accepted answer which is just as good as this one.

Also, I agree with the caveats of preferring setTimeout and asynchronous function calling but sometimes e.g., when building tests, you just need a synchronous wait command...

function wait(ms) {
    var start = Date.now(),
        now = start;
    while (now - start < ms) {
      now = Date.now();
    }
}

if you want it in seconds, divide start ms by 1000 on the while check...