Base class for the thread state. More...

#include <SgUctSearch.h>

Public Member Functions
	SgUctThreadState (unsigned int threadId, int moveRange=0)
virtual	~SgUctThreadState ()
Pure virtual functions

virtual SgUctValue	Evaluate ()=0
	Evaluate end-of-game position.
virtual void	Execute (SgMove move)=0
	Execute a move.
virtual void	ExecutePlayout (SgMove move)=0
	Execute a move in the playout phase.
virtual bool	GenerateAllMoves (SgUctValue count, std::vector< SgUctMoveInfo > &moves, SgUctProvenType &provenType)=0
	Generate moves.
virtual SgMove	GeneratePlayoutMove (bool &skipRaveUpdate)=0
	Generate random move.
virtual void	StartSearch ()=0
	Start search.
virtual void	TakeBackInTree (std::size_t nuMoves)=0
	Take back moves played in the in-tree phase.
virtual void	TakeBackPlayout (std::size_t nuMoves)=0
	Take back moves played in the playout phase.
Virtual functions

virtual void	GameStart ()
	Function that will be called by PlayGame() before the game.
virtual void	StartPlayouts ()
	Function that will be called at the beginning of the playout phase.
virtual void	StartPlayout ()
	Function that will be called at the beginning of each playout.
virtual void	EndPlayout ()
	Function that will be called after each playout.
Public Attributes
const unsigned int	m_threadId
	Number of the thread between 0 and SgUctSearch::NumberThreads() - 1.
bool	m_isSearchInitialized
bool	m_isTreeOutOfMem
	Flag indicating the a node could not be expanded, because the maximum tree size was reached.
SgUctGameInfo	m_gameInfo
boost::scoped_array< std::size_t >	m_firstPlay
	Local variable for SgUctSearch::UpdateRaveValues().
boost::scoped_array< std::size_t >	m_firstPlayOpp
	Local variable for SgUctSearch::UpdateRaveValues().
std::vector< SgUctMoveInfo >	m_moves
	Local variable for SgUctSearch::PlayInTree().
std::vector< SgMove >	m_excludeMoves
	Local variable for SgUctSearch::CheckCountAbort().
int	m_randomizeCounter
	Thread's counter for Randomized Rave in SgUctSearch::SelectChild().

Detailed Description

Base class for the thread state.

Subclasses must be thread-safe, it must be possible to use different instances of this class in different threads (after construction, the constructor does not need to be thread safe). Beware not to use classes that are not thread-safe, because they use global variables (e.g. SgRandom::Global())

Note:: Technically it is possible to use a non-thread safe implementation of subclasses, as long as the search is run with only one thread.

Definition at line 271 of file SgUctSearch.h.

Constructor & Destructor Documentation

SgUctThreadState::SgUctThreadState	(	unsigned int	threadId,
		int	moveRange = `0`
	)

Definition at line 111 of file SgUctSearch.cpp.

References m_firstPlay, and m_firstPlayOpp.

SgUctThreadState::~SgUctThreadState ( ) [virtual]

Definition at line 123 of file SgUctSearch.cpp.

Member Function Documentation

void SgUctThreadState::EndPlayout ( ) [virtual]

Function that will be called after each playout.

Default implementation does nothing.

Definition at line 127 of file SgUctSearch.cpp.

Referenced by SgUctSearch::PlayGame(), and SgUctSearch::SearchOnePly().

virtual SgUctValue SgUctThreadState::Evaluate ( ) [pure virtual]

Evaluate end-of-game position.

Will only be called if GenerateAllMoves() or GeneratePlayoutMove() returns no moves. Should return larger values if position is better for the player to move.

Referenced by SgUctSearch::PlayGame(), and SgUctSearch::SearchOnePly().

virtual void SgUctThreadState::Execute ( SgMove move ) [pure virtual]

Execute a move.

Parameters:

move

The move

Referenced by SgUctSearch::PlayInTree(), and SgUctSearch::SearchOnePly().

virtual void SgUctThreadState::ExecutePlayout ( SgMove move ) [pure virtual]

Execute a move in the playout phase.

For optimization if the subclass uses uses a different game state representation in the playout phase. Otherwise the function can be implemented in the subclass by simply calling Execute().

Parameters:

move

The move

Referenced by SgUctSearch::PlayoutGame().

void SgUctThreadState::GameStart ( ) [virtual]

Function that will be called by PlayGame() before the game.

Default implementation does nothing.

Definition at line 132 of file SgUctSearch.cpp.

Referenced by SgUctSearch::PlayGame(), and SgUctSearch::SearchOnePly().

virtual bool SgUctThreadState::GenerateAllMoves	(	SgUctValue	count,
		std::vector< SgUctMoveInfo > &	moves,
		SgUctProvenType &	provenType
	)			`[pure virtual]`

Generate moves.

Moves will be explored in the order of the returned list. If return is true, trees under children will be deleted.

Parameters:

	count	Number of times node has been visited. For knowledge- based computations.
`[out]`	moves	The generated moves or empty list at end of game
`[out]`	provenType

Referenced by SgUctSearch::GenerateAllMoves(), SgUctSearch::PlayInTree(), and SgUctSearch::SearchOnePly().

virtual SgMove SgUctThreadState::GeneratePlayoutMove ( bool & skipRaveUpdate ) [pure virtual]

Generate random move.

Generate a random move in the play-out phase (outside the UCT tree).

Parameters:

[out] skipRaveUpdate This value should be set to true, if the move should be excluded from RAVE updates. Otherwise it can be ignored.

Returns:: The move or SG_NULLMOVE at the end of the game.

Referenced by SgUctSearch::PlayoutGame().

void SgUctThreadState::StartPlayout ( ) [virtual]

Function that will be called at the beginning of each playout.

Default implementation does nothing.

Definition at line 137 of file SgUctSearch.cpp.

Referenced by SgUctSearch::PlayGame(), and SgUctSearch::SearchOnePly().

void SgUctThreadState::StartPlayouts ( ) [virtual]

Function that will be called at the beginning of the playout phase.

Will be called only once (not once per playout!). Can be used for example to save some state of the current position for more efficient implementation of TakeBackPlayout(). Default implementation does nothing.

Definition at line 142 of file SgUctSearch.cpp.

Referenced by SgUctSearch::PlayGame(), and SgUctSearch::SearchOnePly().

virtual void SgUctThreadState::StartSearch ( ) [pure virtual]

Start search.

This function should do any necessary preparations for playing games in the thread, like initializing the thread's copy of the game state from the global game state. The function does not have to be thread-safe.

Referenced by SgUctSearch::GenerateAllMoves(), SgUctSearch::SearchOnePly(), and SgUctSearch::StartSearch().

virtual void SgUctThreadState::TakeBackInTree ( std::size_t nuMoves ) [pure virtual]

Take back moves played in the in-tree phase.

Referenced by SgUctSearch::PlayGame(), and SgUctSearch::SearchOnePly().

virtual void SgUctThreadState::TakeBackPlayout ( std::size_t nuMoves ) [pure virtual]

Take back moves played in the playout phase.

The search engine does not assume that the moves are really taken back after this function is called. If the subclass implements the playout in s separate state, which is initialized in StartPlayout() and does not support undo, the implementation of this function can be left empty in the subclass.

Referenced by SgUctSearch::PlayGame(), and SgUctSearch::SearchOnePly().

Member Data Documentation

std::vector<SgMove> SgUctThreadState::m_excludeMoves

Local variable for SgUctSearch::CheckCountAbort().

Reused for efficiency.

Definition at line 302 of file SgUctSearch.h.

Referenced by SgUctSearch::CheckCountAbort().

boost::scoped_array<std::size_t> SgUctThreadState::m_firstPlay

Local variable for SgUctSearch::UpdateRaveValues().

Reused for efficiency. Stores the first time a move was played by the color to play at the root position (move is used as an index, do m_moveRange must be > 0); numeric_limits<size_t>::max(), if the move was not played.

Definition at line 290 of file SgUctSearch.h.

Referenced by SgUctThreadState(), and SgUctSearch::UpdateRaveValues().

boost::scoped_array<std::size_t> SgUctThreadState::m_firstPlayOpp

Local variable for SgUctSearch::UpdateRaveValues().

Like m_firstPlayToPlay, but for opponent color.

Definition at line 294 of file SgUctSearch.h.

Referenced by SgUctThreadState(), and SgUctSearch::UpdateRaveValues().

SgUctGameInfo SgUctThreadState::m_gameInfo

Definition at line 283 of file SgUctSearch.h.

Referenced by SgUctSearch::LastGameInfo(), SgUctSearch::PlayGame(), SgUctSearch::PlayInTree(), SgUctSearch::PlayoutGame(), SgUctSearch::SearchLoop(), SgUctSearch::SearchOnePly(), and SgUctSearch::UpdateRaveValues().