template<Domain D, class Dist = StateHashDistribution< D >, ADS::WorkerExecutor Executor = ADS::ThreadPool, class Open = std::conditional_t< std::is_integral_v< cost_t< D > > , BucketOpenList< Node< state_t< D > , cost_t< D > > > , HeapOpenList< Node< state_t< D > , cost_t< D > > > >>
class PBeFS_di_unipi_it::HDAStar< D, Dist, Executor, Open >
Hash Distributed A* on a shared-memory machine.
Every worker runs A* on its own OPEN and CLOSED lists, and a global function Dist assigns every state to the worker that owns it: a node generated by a worker is sent to its owner, which checks it against its closed list and possibly adds it to its OPEN list [see section 4.1 of Fukunaga et al., 2017, and Kishimoto, Fukunaga and Botea, AIJ 2013]. Nodes are sent asynchronously, packed in batches of batch nodes, and an outbox not yet full is flushed every flush_period expansions and before the worker waits. The goal test is done at the expansion, the cost of the best goal found (the incumbent) prunes every node with f not smaller, and the search ends when no worker has a node with f smaller than the incumbent and no node is travelling, which the mailbox of ADS detects.
The node of a state belongs to its owner, which is the only worker that writes it; parent pointers cross the workers, and they are followed only after all the workers have finished.
1.15.0