/* These macros implement functions and structs for a general queue.
Macro 'DEFINE_QUEUE_P(TYPEDEF)' is to define the new queue type for
TYPEDEF', and macro 'DECLARE_QUEUE_P' is to declare external queue
/* These macros implement functions and structs for a general queue.
Macro 'DEFINE_QUEUE_P(TYPEDEF)' is to define the new queue type for
TYPEDEF', and macro 'DECLARE_QUEUE_P' is to declare external queue