这个do_action() 和apply_filters() 都是

WP_Hook::apply_filters()

方法调用中注册的回调sequential 订单号(src).

Here\'s a simple test:

让我们定义一个回调包装器：

$callback_gen = function( $seconds ) { 
    return function() use ( $seconds ) {
        sleep( $seconds ); 
        printf( \'%s finished\' . PHP_EOL, $seconds ); 
    };
};

接下来，我们将回调注册到mytest 措施：

add_action( \'mytest\', $callback_gen( 3 ) );
add_action( \'mytest\', $callback_gen( 5 ) );
add_action( \'mytest\', $callback_gen( 1 ) );

然后调用回调并测量所需的时间：

$start = microtime( true );
do_action( \'mytest\' );
$stop = microtime( true );

并将其显示为：

echo number_format( $stop - $start, 5 );

以下是5次测试运行的输出：

3 finished 
5 finished 
1 finished 
9.00087

3 finished 
5 finished 
1 finished 
9.00076

3 finished 
5 finished 
1 finished 
9.00101

3 finished 
5 finished 
1 finished 
9.00072

3 finished 
5 finished 
1 finished 
9.00080

其中每次运行的顺序相同，总时间为9秒，与连续运行顺序相同。