WordPress at a glance
action is not described

action_scheduler_before_execute action-hook . WC 1.0

Usage

add_action( 'action_scheduler_before_execute', 'action_function_name_904', 10, 2 );
function action_function_name_904( $action_id, $context ){
	// action...
}
$action_id
-
$context
-

Where the hook is called

ActionScheduler_Abstract_QueueRunner::process_action()
action_scheduler_before_execute
woocommerce/packages/action-scheduler/classes/abstracts/ActionScheduler_Abstract_QueueRunner.php 53
do_action( 'action_scheduler_before_execute', $action_id, $context );

Where in WP core the hook is used WooCommerce

woocommerce/packages/action-scheduler/classes/ActionScheduler_FatalErrorMonitor.php 20
add_action( 'action_scheduler_before_execute', array( $this, 'track_current_action' ), 0, 1 );
woocommerce/packages/action-scheduler/classes/ActionScheduler_FatalErrorMonitor.php 30
remove_action( 'action_scheduler_before_execute', array( $this, 'track_current_action' ), 0 );
woocommerce/packages/action-scheduler/classes/WP_CLI/ActionScheduler_WPCLI_QueueRunner.php 79
add_action( 'action_scheduler_before_execute', array( $this, 'before_execute' ) );