Question

here i have written a window service, it job is to read files from one folder and sending the same content to database and sending readed files to some other folder

now my service having timer event has sets it was about of 10000 means ten seconds,
now if a process a files between 100 – 1000 ,with in 10 sec it was doing that job processing good output, case if process the files 6000 – 9000 at that particular situation my service is not producing exact out, it was not able to do that job in 10000 (ten seconds), so i need when service in middle of the job it should get interrupted since by timer completed but real scenario it should completed the particular job.

kindly give some suggestions, it would be appreciated

Answer 1

Different approaches that can work:

1. Have the method called by the timer safe for re-entrance and then not worry about it. This tends to be either very easy to do (the task done is inherently re-entrant) or pretty tricky (if it’s not naturally re-entrant you have to consider the effects of multiple threads upon every single thing hit during the task).

2. Have a lock in the operation, so different threads from different timer events just wait on each other. Note that you must know that there will not be several tasks in a row that take longer than the time interval, as otherwise you will have an ever-growing queue of threads waiting for their chance to run, and the amount of resources consumed just by waiting to do something will grown with it.

3. Have the timer not set to have a recurring interval, but rather re-set it at the end of each task, so the next task will happen X seconds after the current one finishes.

4. Have a lock and obtain it only if you don’t have to block. If you would have to block then a current task is still running, and we just let this time slot go by to stay out of it’s ways.

After all, there’ll be another timer event along in 10 seconds:

private static void TimerHandler(object state)
{
  if(!Monitor.TryEnter(LockObject))
    return;//last timer still running
  try
  {
    //do useful stuff here.
  }
  finally
  {
    Monitor.Exit(LockObject);
  }
}