Header file for the class template ConcurrentClosed, the closed list that the workers of SPAStar and MQAStar share, taken from the set of data structures chosen [see Structures.h]. More...

#include "PBeFS/astar/Structures.h"

Detailed Description

Header file for the class template ConcurrentClosed, the closed list that the workers of SPAStar and MQAStar share, taken from the set of data structures chosen [see Structures.h].

A ConcurrentClosed< D , Lock > maps the states of the Domain D to their canonical Node and protects the fields of the nodes that change during the search (g, parent, op, closed and expanded) with locks of type Lock. It has a constructor taking the Domain, the type Local of the nodes that a worker allocates, whose stored() is their number in the table, lock( n ), the lock of the node n, under which a worker reads and writes those fields, the type Successor of a state generated with its g, h, hash and operator [see OperatorDomain], prefetch( hash ), which brings in the cache what an update() of a state of that hash reads first, so that a worker overlaps the misses of all the successors of a node, and update( t , hash , g , h , parent , op , local , duplicates ), which records the path to the state t, of hash hash, of cost g through parent and the operator op: it returns the node of t if t is new or g is smaller than its g, which then is set to g with the parent and the operator and the node is no longer closed, and nullptr otherwise, adding 1 to duplicates. The fields of a node returned may be read only under its lock, but for h, which never changes.

Author: Donato Meoli
Dipartimento di Informatica
Università di Pisa