title: Can single delayed job worker start the next job before the ongoing job ends?
body: <p>I have implemented API rate limiting in my application for calling 3rd party API service which limits the number of requests made to service in a specified time interval.</p>
  
  <p>I went through delayed job documentation and could not find the information i was looking for. </p>
  
  <p>My case is;</p>
  
  <p>If there is a really short amount of time, let's say 5 seconds, between 2 delayed jobs, what will the worker do?</p>
  
  <p>Will it wait for the first job to finish even though the second job execution time has arrived, or will it start the job on the specified time?</p>
  
  <p>If the latter, It will break my rate limiting implementation since API is only letting me 60 requests per minute and and both jobs will just limit themselves to 60 requests per minute and in total both jobs will try to send around 120 requests in a minute.</p>
  
  <p>Thanks in advance, cheers!</p>