wp-includes/cron.php:1046Runs scheduled callbacks or spawns cron for all scheduled events.
int|falsefunction _wp_cron() { // Prevent infinite loops caused by lack of wp-cron.php. if ( str_contains( $_SERVER['REQUEST_URI'], '/wp-cron.php' ) || ( defined( 'DISABLE_WP_CRON' ) && DISABLE_WP_CRON ) ) { return 0; } $crons = wp_get_ready_cron_jobs(); if ( empty( $crons ) ) { return 0; } $gmt_time = microtime( true ); $keys = array_keys( $crons ); if ( isset( $keys[0] ) && $keys[0] > $gmt_time ) { return 0; } $schedules = wp_get_schedules(); $results = array(); foreach ( $crons as $timestamp => $cronhooks ) { if ( $timestamp > $gmt_time ) { break; } foreach ( (array) $cronhooks as $hook => $args ) { if ( isset( $schedules[ $hook ]['callback'] ) && ! call_user_func( $schedules[ $hook ]['callback'] ) ) { continue; } $results[] = spawn_cron( $gmt_time ); break 2; } } if ( in_array( false, $results, true ) ) { return false; } return count( $results );}Introduced in 5.7.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/cron.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.