Class CForest

Inheritance Relationships

Base Type

Class Documentation

class CForest : public ompl::base::Planner

Coupled Forest of Random Engrafting Search Trees.

CForest is designed to be used with any random tree algorithm that operates in any configuration space such that: 1) the search tree has almost sure convergence to the optimal solution and 2) the configuration space obeys the triangle inequality. It relies in the OptimizationObjective set for the underlying planners.

Short description

CForest (Coupled Forest of Random Engrafting Search Trees) is a parallelization framework that is designed for single-query shortest path planning algorithms. It is not a planning algorithm per se.

See also the extensive documentation here.

External documentation

M. Otte, N. Correll, C-FOREST: Parallel Shortest Path Planning With Superlinear Speedup, IEEE Transactions on Robotics, Vol 20, No 3, 2013. DOI: 10.1109/TRO.2013.2240176[PDF]

Public Functions

CForest(const base::SpaceInformationPtr &si)
~CForest() override
virtual void getPlannerData(base::PlannerData &data) const override

Get information about the current run of the motion planner. Repeated calls to this function will update data (only additions are made). This is useful to see what changed in the exploration datastructure, between calls to solve(), for example (without calling clear() in between).

virtual void clear() override

Clear all internal datastructures. Planner settings are not affected. Subsequent calls to solve() will ignore all previous work.

template<class T>
inline void addPlannerInstance()

Add an specific planner instance.

template<class T>
inline void addPlannerInstances(std::size_t num = 2)

Add specific planner instances. CFOREST sets the planner’s parameter named focus_search (if present) to the current value of CFOREST’s focus_search parameter.

inline void clearPlannerInstances()

Remove all planner instances.

inline base::PlannerPtr &getPlannerInstance(const std::size_t idx)

Return an specific planner instance.

virtual void setup() override

Perform extra configuration steps, if needed. This call will also issue a call to ompl::base::SpaceInformation::setup() if needed. This must be called before solving.

virtual base::PlannerStatus solve(const base::PlannerTerminationCondition &ptc) override

Function that can solve the motion planning problem. This function can be called multiple times on the same problem, without calling clear() in between. This allows the planner to continue work for more time on an unsolved problem, for example. If this option is used, it is assumed the problem definition is not changed (unpredictable results otherwise). The only change in the problem definition that is accounted for is the addition of starting or goal states (but not changing previously added start/goal states). If clearQuery() is called, the planner may retain prior datastructures generated from a previous query on a new problem definition. The function terminates if the call to ptc returns true.

inline void addSampler(const base::StateSamplerPtr &sampler)
inline void setFocusSearch(const bool focus)

Option to control whether the search is focused during the search.

inline bool getFocusSearch() const

Get the state of the search focusing option.

void setNumThreads(unsigned int numThreads = 0)

Set default number of threads to use when no planner instances are specified by the user.

inline unsigned int getNumThreads()

Get default number of threads used by CForest when no planner instances are specified by the user.

std::string getBestCost() const

Get best cost among all the planners.

std::string getNumPathsShared() const

Get number of paths shared by the algorithm.

std::string getNumStatesShared() const

Get number of states actually shared by the algorithm.

Protected Functions

void solve(base::Planner *planner, const base::PlannerTerminationCondition &ptc)

Manages the call to solve() for each individual planner.

Protected Attributes

base::OptimizationObjectivePtr opt_

Optimization objective taken into account when planning.

std::vector<base::PlannerPtr> planners_

The set of planners to be used.

std::vector<base::StateSamplerPtr> samplers_

The set of sampler allocated by the planners.

std::unordered_set<const base::State*> statesShared_

Stores the states already shared to check if a specific state has been shared.

base::Cost bestCost_

Cost of the best path found so far among planners.

unsigned int numPathsShared_ = {0u}

Number of paths shared among threads.

unsigned int numStatesShared_ = {0u}

Number of states shared among threads.

std::mutex newSolutionFoundMutex_

Mutex to control the access to the newSolutionFound() method.

std::mutex addSamplerMutex_

Mutex to control the access to samplers_.

bool focusSearch_ = {true}

Flag to control whether the search is focused.

unsigned int numThreads_

Default number of threads to use when no planner instances are specified by the user.