backdrop_uninstall_modules in includes/install.inc

Uninstalls a given list of disabled modules.

drupal_set_installed_schema_version in includes/drupal.inc

Update the installed version information for a module.

module_enable in includes/module.inc

Enables or installs a given list of modules.

system_install in modules/system/system.install

Implements hook_install().

update_batch in includes/update.inc

Starts the database update batch process.

update_do_one in includes/update.inc

Performs one update and stores the results for display on the results page.

UpdateDrupal7TestCase::testAvailableUpdates in modules/simpletest/tests/update.test

Tests that updates will be executed in the correct order.

UpdateScriptFunctionalTest::testRequirements in modules/system/tests/system.test

Tests that requirements warnings and errors are correctly displayed.

UpdateScriptFunctionalTest::testSuccessfulUpdateFunctionality in modules/system/tests/system.test

Tests update.php after performing a successful update.