#include "planner.h"
#include "node.h"
#include <iostream>
-#include <vector>
+#include <iterator>
using namespace std;
using namespace __gnu_cxx;
+extern "C" void* executeNode(void* arg);
+
+struct ExecutionStuff {
+ sem_t* nodes;
+ sem_t* list;
+ Node* node;
+ queue<Node*>* execQueue;
+};
+
Planner::Planner(std::vector<Action> actions, Literals init, Literals goal){
_init = init;
_goal = goal;
addNode(_start);
for(vector<Action>::iterator action = actions.begin(); action != actions.end(); ++action){
- const Literals& effects = action->effects(0);
+ Action* act = new Action(*action);
+ _actions.push_back(act);
+ const Literals& effects = act->effects(0);
for (Literals::const_iterator effect = effects.begin(); effect != effects.end(); ++effect){
- cerr << "Adding effect: '" << *effect << "', action: " << action->name() << endl;
- _actions[*effect] = *action;
+ _actionEffects[*effect] = act;
}
}
- cout << "Number of actions: " << _actions.size() << endl;
makePlan(_finish);
}
Planner::~Planner(){
- for (hash_map<string,Node*>::iterator node = _addedNodes.begin(); node != _addedNodes.end(); ++node){
- cerr << "Deleting node " << node->second->action().name() << endl;
- delete node->second;
+ //Iterating over the remaining nodes and deleting them
+ for (vector<Node*>::iterator node = _addedNodes.begin(); node != _addedNodes.end(); ++node){
+ delete *node;
+ }
+ //iterating over the the remaining actions and deleting them
+ for (vector<Action*>::iterator action = _actions.begin(); action != _actions.end(); ++action){
+ delete *action;
}
}
void Planner::makePlan(Node* node){
addNode(node);
- cerr << "Fetching preconditions for action: " << node->action().name() << ".. ";
- const Preconditions& preconds = node->action().preconditions();
- cerr << "done" << endl;
-
+ const Preconditions& preconds = node->action()->preconditions();
if (preconds.size() == 0){
- cerr << "Found no preconds" << endl;
+ //Add the node as a child to start if there are no preconditions
_start->addChild(node);
}else{
+ //iterate over the preconditions
for (Preconditions::const_iterator precond = preconds.begin(); precond != preconds.end(); ++precond){
- cerr << "Looking for: '" << precond->first << "'" << endl;
- hash_map<string,Node*>::iterator addedNode = _addedNodes.find(precond->first);
- if(addedNode != _addedNodes.end()){
- cerr << "Using already added node" << endl;
+ //Check if there is a node with this precondition as an effect
+ hash_map<string,Node*>::iterator addedNode = _addedEffects.find(precond->first);
+ if(addedNode != _addedEffects.end()){
+ //Use this node if there is one
+ //cerr << "Using already added node for effect " << precond->first << ", on node: " << node->action()->name() << endl;
addedNode->second->addChild(node);
}else {
- hash_map<string, Action>::iterator action = _actions.find(precond->first);
- if (action != _actions.end()){
- cerr << "Adding new node" << endl;
+ //Check if there is an action which satisfies this effect
+ hash_map<string, Action*>::iterator action = _actionEffects.find(precond->first);
+ if (action != _actionEffects.end()){
+ //Create a new node for the found effect and add the current
+ //one as a child
Node* newnode = new Node(action->second);
newnode->addChild(node);
makePlan(newnode);
}else if (precond->second){
- cerr << "Action with effect: " << precond->first << " not found!" << endl;
- cerr << "This is a hard precondition, so this action and the children can't be executed." << endl;
+ //No such action found, and since it was a hard preconition
+ //we need to stop here.
+ cerr << "Could not satisfy the effect: " << precond->first << " for: " << node->action()->name() << endl;
return;
}else{
- cerr << "Action with effect: " << precond->first << " not found!" << endl;
- cerr << "This is a soft precondition, so we will continue" << endl;
+ //No action found, but it was a soft precondition, so we can
+ //satisfy it and continue.
+ //cerr << "Could not satisfy the effect: " << precond->first << " for: " << node->action()->name() << endl;
+ node->satisfyCondition(precond->first);
+ _start->addChild(node);
}
}
}
}
void Planner::addNode(Node* node){
- cerr << "Adding node for action: " << node->action().name() << endl;
- const Literals& effects = node->action().effects(0);
- cerr << "Number of effects: " << effects.size() << endl;
+ const Literals& effects = node->action()->effects(0);
+ _addedNodes.push_back(node);
+ //Iterate over the effects for this node and add them to the map.
for (Literals::const_iterator effect = effects.begin(); effect != effects.end(); ++effect){
- cout << "Adding node for effect: " << *effect << endl;
- _addedNodes[*effect] = node;
+ _addedEffects[*effect] = node;
}
}
void Planner::execute(){
- _start->execute(Literals());
- /*for (hash_map<string,Node*>::iterator node = _addedNodes.begin(); node != _addedNodes.end(); ++node){
- if (node->second->executed()){
- }*/
- _start->execute(Literals());
+ executePlan();
+
+ if (cleanupExecution() <= 1){
+ cerr << "Non of the remaining actions could be executed, quiting." << endl;
+ return;
+ }
+
+ cout << "Effects achieved so far: " << _init.size() << ": ";
+ copy(_init.begin(), _init.end(), ostream_iterator<string>(cout, " "));
+ cout << endl;
+
+ if (_actions.size() == 0){
+ //Nothing left to do, quitting.
+ return;
+ }
+ //REPLANNING
+ cout << "Replanning..." << endl;
+
+ replan();
+
+ if (_addedNodes.size() <= 2){
+ cerr << "No actions to execute, quiting." << endl;
+ return;
+ }
+ execute();
+
+}
+
+void Planner::executePlan(){
+ sem_init(&_nodes, 0, 1);
+ sem_init(&_list, 0, 1);
+
+ //We've "executed" the start node.
+ _executedNodes.push(_start);
+ int executions = 1;
+
+ //As long as there executed nodes in the queue.
+ while (executions > 0){
+ //Wait for a node to be added to the queue
+ sem_wait(&_nodes);
+ --executions;
+
+ //Pop the first node from the queue.
+ sem_wait(&_list);
+ Node* node = _executedNodes.front();
+ _executedNodes.pop();
+ sem_post(&_list);
+
+ //We don't need to continue if the end node was executed.
+ if (node == _finish)
+ return;
+ executions += executeChildren(node);
+
+ }
+}
+
+
+int Planner::executeChildren(Node* node){
+
+ vector<Node*> children = node->children();
+
+ int executions = 0;
+ //Iterate over the children for this node
+ for(vector<Node*>::iterator child = children.begin(); child != children.end(); ++child){
+ //Satisfy the preconditions the current node had as effect.
+ if ((*child)->satisfyConditions(node->effects())){
+ //If all preconditions were satisified we can create a new thread
+ //and execute this child.
+ ++executions;
+ pthread_attr_t tattr;
+ pthread_t tid;
+ pthread_attr_init(&tattr);
+ pthread_attr_setscope(&tattr, PTHREAD_SCOPE_SYSTEM);
+ //Create a struct object for the thread and add the
+ //needed members to it.
+ ExecutionStuff* es = new ExecutionStuff;
+ es->nodes = &_nodes;
+ es->list = &_list;
+ es->node = *child;
+ es->execQueue = &_executedNodes;
+ pthread_create(&tid, &tattr, executeNode, es);
+ }
+ }
+ return executions;
+}
+
+int Planner::cleanupExecution(){
+ //Clearing the init and goal vectors, new effects will be added below.
+ _init.clear();
+ _goal.clear();
+ Preconditions goal = _finish->preconditions();
+ for (Preconditions::const_iterator precond = goal.begin(); precond != goal.end(); ++precond){
+ _goal.push_back(precond->first);
+ }
+
+ if (goal.size() == 0)
+ exit(0);
+
+ cout << "Unsatisfied preconditions so far: " << _goal.size() << ": ";
+ copy(_goal.begin(), _goal.end(), ostream_iterator<string>(cout, " "));
+ cout << endl;
+
+ //iterator for inserting effects at the end of _init
+ back_insert_iterator<Literals> ii(_init);
+
+ int executions = 0;
+ //Iterate throu the nodes, to see what's been done
+ for (vector<Node*>::iterator node = _addedNodes.begin(); node != _addedNodes.end(); ++node){
+ if ((*node)->executed()){
+ //Node was executed, adding the effects to _init.
+ executions++;
+ const Literals& effects = (*node)->effects();
+ copy(effects.begin(),effects.end(),ii);
+
+ vector<Action*>::iterator action = find(_actions.begin(), _actions.end(), (*node)->action());
+ if (action != _actions.end()){
+ //The action can be deleted, since it's already been executed.
+ delete *action;
+ _actions.erase(action);
+ }
+ }
+ //The node is not needed anymore
+ delete *node;
+ }
+ //Clearing the vectors and maps, since they are obsolete now.
+ _addedNodes.clear();
+ _addedEffects.clear();
+ _actionEffects.clear();
+ return executions;
+}
+
+void Planner::replan(){
+
+ //Adding the effecs for the remaining actions.
+ for (vector<Action*>::iterator action = _actions.begin(); action != _actions.end(); ++action){
+ const Literals& effects = (*action)->effects(0);
+ for (Literals::const_iterator effect = effects.begin(); effect != effects.end(); ++effect){
+ _actionEffects[*effect] = *action;
+ }
+ }
+ _start = new StartNode(_init);
+ _finish = new EndNode(_goal);
+ addNode(_start);
+ makePlan(_finish);
+}
+void* executeNode(void* arg){
+ ExecutionStuff* es = (ExecutionStuff*)arg;
+
+ es->node->execute();
+
+ sem_wait(es->list);
+ //Add this node to the queue with executed nodes
+ es->execQueue->push(es->node);
+ sem_post(es->list);
+
+ //Signal that the node is available.
+ sem_post(es->nodes);
+
+ pthread_exit((void*)0);
}