function _lock_id

7.x lock.inc _lock_id()
6.x lock.inc _lock_id()

Helper function to get this request's unique id.

Related topics

Functions to coordinate long-running operations across requests.
In most environments, multiple Drupal page requests (a.k.a. threads or processes) will execute in parallel. This leads to potential conflicts or race conditions when two requests execute the same code at the same time. A common example of this is a…
3 calls to _lock_id()
lock_acquire in drupal-6.x/includes/lock.inc
Acquire (or renew) a lock, but do not block if it fails.
lock_release in drupal-6.x/includes/lock.inc
Release a lock previously acquired by lock_acquire().
lock_release_all in drupal-6.x/includes/lock.inc
Release all previously acquired locks.

File

drupal-6.x/includes/lock.inc, line 74
A database-mediated implementation of a locking mechanism.

Code

function _lock_id() {
  static $lock_id;

  if (!isset($lock_id)) {
    // Assign a unique id.
    $lock_id = uniqid(mt_rand(), TRUE);
    // We only register a shutdown function if a lock is used.
    register_shutdown_function('lock_release_all', $lock_id);
  }
  return $lock_id;
}