function variable_initialize

Loads the persistent variable table.

The variable table is composed of values that have been saved in the table with variable_set() as well as those explicitly specified in the configuration file.

3 calls to variable_initialize()
DrupalWebTestCase::refreshVariables in drupal/modules/simpletest/drupal_web_test_case.php
Refresh the in-memory set of variables. Useful after a page request is made that changes a variable in a different thread.
_drupal_bootstrap_variables in drupal/includes/bootstrap.inc
Loads system variables and all enabled bootstrap modules.
_menu_check_rebuild in drupal/includes/menu.inc
Checks whether a menu_rebuild() is necessary.

File

drupal/includes/bootstrap.inc, line 1172
Functions that need to be loaded on every Drupal request.

Code

function variable_initialize($conf = array()) {

  // NOTE: caching the variables improves performance by 20% when serving
  // cached pages.
  if ($cached = cache_get('variables', 'cache_bootstrap')) {
    $variables = $cached->data;
  }
  else {

    // Cache miss. Avoid a stampede.
    $name = 'variable_init';
    if (!lock_acquire($name, 1)) {

      // Another request is building the variable cache.
      // Wait, then re-run this function.
      lock_wait($name);
      return variable_initialize($conf);
    }
    else {

      // Proceed with variable rebuild.
      $variables = array_map('unserialize', db_query('SELECT name, value FROM {variable}')
        ->fetchAllKeyed());
      cache_set('variables', $variables, 'cache_bootstrap');
      lock_release($name);
    }
  }
  foreach ($conf as $name => $value) {
    $variables[$name] = $value;
  }
  return $variables;
}