WordPress at a glance
function is not described

wp_update_term_count_now() WP 2.5.0

Perform term count update immediately.

No Hooks.

Return

true. Always true when complete.

Usage

wp_update_term_count_now( $terms, $taxonomy );
$terms(array) (required)
The term_taxonomy_id of terms to update.
$taxonomy(string) (required)
The context of the term.

Code of wp update term count now: wp-includes/taxonomy.php VER 5.0.3

<?php
function wp_update_term_count_now( $terms, $taxonomy ) {
	$terms = array_map('intval', $terms);

	$taxonomy = get_taxonomy($taxonomy);
	if ( !empty($taxonomy->update_count_callback) ) {
		call_user_func($taxonomy->update_count_callback, $terms, $taxonomy);
	} else {
		$object_types = (array) $taxonomy->object_type;
		foreach ( $object_types as &$object_type ) {
			if ( 0 === strpos( $object_type, 'attachment:' ) )
				list( $object_type ) = explode( ':', $object_type );
		}

		if ( $object_types == array_filter( $object_types, 'post_type_exists' ) ) {
			// Only post types are attached to this taxonomy
			_update_post_term_count( $terms, $taxonomy );
		} else {
			// Default count updater
			_update_generic_term_count( $terms, $taxonomy );
		}
	}

	clean_term_cache($terms, '', false);

	return true;
}