00001 /* Copyright (C) 2015-2017 Michele Colledanchise - All Rights Reserved 00002 * 00003 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), 00004 * to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, 00005 * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: 00006 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. 00007 * 00008 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 00009 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 00010 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 00011 */ 00012 00013 #include <fallback_node.h> 00014 #include <string> 00015 00016 BT::FallbackNode::FallbackNode(std::string name) : ControlNode::ControlNode(name) {} 00017 00018 BT::FallbackNode::~FallbackNode() {} 00019 00020 BT::ReturnStatus BT::FallbackNode::Tick() 00021 { 00022 { 00023 // gets the number of children. The number could change if, at runtime, one edits the tree. 00024 N_of_children_ = children_nodes_.size(); 00025 00026 // Routing the ticks according to the fallback node's logic: 00027 00028 for (unsigned int i = 0; i < N_of_children_; i++) 00029 { 00030 /* Ticking an action is different from ticking a condition. An action executed some portion of code in another thread. 00031 We want this thread detached so we can cancel its execution (when the action no longer receive ticks). 00032 Hence we cannot just call the method Tick() from the action as doing so will block the execution of the tree. 00033 For this reason if a child of this node is an action, then we send the tick using the tick engine. Otherwise we call the method Tick() and wait for the response. 00034 */ 00035 if (children_nodes_[i]->get_type() == BT::ACTION_NODE) 00036 { 00037 // 1) If the child i is an action, read its state. 00038 child_i_status_ = children_nodes_[i]->get_status(); 00039 00040 if (child_i_status_ == BT::IDLE || child_i_status_ == BT::HALTED) 00041 { 00042 // 1.1) If the action status is not running, the sequence node sends a tick to it. 00043 DEBUG_STDOUT(get_name() << "NEEDS TO TICK " << children_nodes_[i]->get_name()); 00044 children_nodes_[i]->tick_engine.Tick(); 00045 00046 // waits for the tick to arrive to the child 00047 do 00048 { 00049 child_i_status_ = children_nodes_[i]->get_status(); 00050 std::this_thread::sleep_for(std::chrono::milliseconds(10)); 00051 } 00052 while (child_i_status_ != BT::RUNNING && child_i_status_ != BT::SUCCESS 00053 && child_i_status_ != BT::FAILURE); 00054 } 00055 } 00056 else 00057 { 00058 // 2) if it's not an action: 00059 // Send the tick and wait for the response; 00060 child_i_status_ = children_nodes_[i]->Tick(); 00061 } 00062 // Ponderate on which status to send to the parent 00063 if (child_i_status_ != BT::FAILURE) 00064 { 00065 if (child_i_status_ == BT::SUCCESS) 00066 { 00067 children_nodes_[i]->set_status(BT::IDLE); // the child goes in idle if it has returned success. 00068 } 00069 // If the child status is not failure, halt the next children and return the status to your parent. 00070 DEBUG_STDOUT(get_name() << " is HALTING children from " << (i+1)); 00071 HaltChildren(i+1); 00072 set_status(child_i_status_); 00073 return child_i_status_; 00074 } 00075 else 00076 { 00077 // the child returned failure. 00078 children_nodes_[i]->set_status(BT::IDLE); 00079 if (i == N_of_children_ - 1) 00080 { 00081 // If the child status is failure, and it is the last child to be ticked, 00082 // then the sequence has failed. 00083 set_status(BT::FAILURE); 00084 return BT::FAILURE; 00085 } 00086 } 00087 } 00088 } 00089 return BT::EXIT; 00090 } 00091 00092 int BT::FallbackNode::DrawType() 00093 { 00094 // Lock acquistion 00095 00096 return BT::SELECTOR; 00097 }