def host_memory_size(obj):
 (s, e) = host_memory_extents(obj)
 assert (e >= s), 'memory extend of negative size'
 return (e - s)

def host_memory_size ( obj ) : ( s , e ) = host_memory_extents ( obj ) assert ( e >= s ) , 'memory extend of negative size' return ( e - s )
get the size of the memory .