PHP mutual exclusion (mutex)

Question

Read some texts about locking in PHP.
They all, mainly, direct to http://php.net/manual/en/function.flock.php .

This page talks about opening a file on the hard-

Answer 1

I recently created my own simple implementation of a mutex-like mechanism using the flock function of PHP. Of course the code below can be improved, but it is working for most use cases.

function mutex_lock($id, $wait=10)
{
  $resource = fopen(storage_path("app/".$id.".lck"),"w");

  $lock = false;
  for($i = 0; $i < $wait && !($lock = flock($resource,LOCK_EX|LOCK_NB)); $i++)
  {
    sleep(1);
  }

  if(!$lock)
  {
    trigger_error("Not able to create a lock in $wait seconds");
  }

  return $resource;
}

function mutex_unlock($id, $resource)
{
  $result = flock($resource,LOCK_UN);
  fclose($resource);

  @unlink(storage_path("app/".$id.".lck"));

  return $result;
}