Changes in the Loggers, motivated by the new tutorial_sequence_star.cpp

Author: Davide Faconti

CMakeLists.txt

@@ -61,9 +61,12 @@ set(BT_Source
         src/behavior_tree.cpp
 
         src/xml_parsing.cpp
-        src/bt_file_logger.cpp
-        3rdparty/tinyXML2/tinyxml2.cpp
 
+        src/loggers/bt_cout_logger.cpp
+        src/loggers/bt_file_logger.cpp
+        src/loggers/bt_minitrace_logger.cpp
+
+        3rdparty/tinyXML2/tinyxml2.cpp
         3rdparty/minitrace/minitrace.cpp
 )
 include_directories(include 3rdparty/)
@@ -75,7 +78,7 @@ find_package(ZMQ)
 if( ZMQ_FOUND )
     message(STATUS "ZeroMQ found.")
     add_definitions( -DZMQ_FOUND )
-    set(BT_Source ${BT_Source} src/bt_zmq_publisher.cpp )
+    set(BT_Source ${BT_Source} src/loggers/bt_zmq_publisher.cpp )
 
     set(BEHAVIOR_TRE_LIBRARIES behavior_tree_core zmq)
 else()
@@ -133,18 +136,16 @@ if( ZMQ_FOUND )
     target_link_libraries(bt_recorder  ${BEHAVIOR_TRE_LIBRARIES} )
 endif()
 
-add_executable(simple_example examples/simple_example.cpp )
-target_link_libraries(simple_example ${BEHAVIOR_TRE_LIBRARIES} )
-
-
-add_executable(tutorial_blackboard examples/tutorial_blackboard.cpp )
-target_link_libraries(tutorial_blackboard ${BEHAVIOR_TRE_LIBRARIES} )
+function(BuildExample filename)
+  add_executable(${filename} examples/${filename}.cpp )
+  target_link_libraries(${filename} ${BEHAVIOR_TRE_LIBRARIES} )
+endfunction()
 
-add_executable(tutorial_programmatic_tree examples/tutorial_programmatic_tree.cpp )
-target_link_libraries(tutorial_programmatic_tree ${BEHAVIOR_TRE_LIBRARIES} )
+BuildExample(tutorial_programmatic_tree)
+BuildExample(tutorial_factory_tree)
+BuildExample(tutorial_sequence_star)
+BuildExample(tutorial_blackboard)
 
-add_executable(tutorial_factory_tree examples/tutorial_factory_tree.cpp )
-target_link_libraries(tutorial_factory_tree ${BEHAVIOR_TRE_LIBRARIES} )
 
 ######################################################
 # INSTALLATION OF LIBRARY AND EXECUTABLE

examples/simple_example.cpp

@@ -0,0 +1,128 @@
+#include "behavior_tree_core/xml_parsing.h"
+#include "behavior_tree_logger/bt_cout_logger.h"
+#include "behavior_tree_logger/bt_file_logger.h"
+
+using namespace BT;
+
+
+NodeStatus checkBattery()
+{
+    std::cout << "[ Battery: OK ]" << std::endl;
+    return NodeStatus::SUCCESS;
+}
+
+NodeStatus CheckTemperature()
+{
+    std::cout << "[ Temperature: OK ]" << std::endl;
+    return NodeStatus::SUCCESS;
+}
+
+// This is an asynchronous operation that will run in a separate thread
+class MoveAction: public ActionNode
+{
+public:
+    MoveAction(const std::string& name): ActionNode(name) {}
+    NodeStatus tick() override
+    {
+        std::cout << "[ Move: started ]" << std::endl;
+        std::this_thread::sleep_for( std::chrono::milliseconds(80) );
+        std::cout << "[ Move: finished ]" << std::endl;
+        return NodeStatus::SUCCESS;
+    }
+};
+
+// clang-format off
+
+const std::string xml_text_sequence = R"(
+
+ <root main_tree_to_execute = "MainTree" >
+
+     <BehaviorTree ID="MainTree">
+        <Sequence name="root">
+            <BatteryOK/>
+            <TemperatureOK />
+            <Move/>
+        </Sequence>
+     </BehaviorTree>
+
+ </root>
+ )";
+
+const std::string xml_text_sequence_star = R"(
+
+ <root main_tree_to_execute = "MainTree" >
+
+     <BehaviorTree ID="MainTree">
+        <SequenceStar name="root">
+             <BatteryOK/>
+             <TemperatureOK />
+             <Move/>
+        </SequenceStar>
+     </BehaviorTree>
+
+ </root>
+ )";
+
+// clang-format on
+
+void Assert(bool condition)
+{
+    if( !condition ) throw std::runtime_error("this is not what I expected");
+}
+
+int main()
+{
+    BehaviorTreeFactory factory;
+    factory.registerSimpleCondition("TemperatureOK", std::bind( checkBattery ));
+    factory.registerSimpleCondition("BatteryOK", std::bind( CheckTemperature ));
+    factory.registerNodeType<MoveAction>("Move");
+
+    // Loog at the state transitions and messages using either
+    // xml_text_sequence and xml_text_sequence_star
+
+    // The main difference that you should notice is that the
+    // actions BatteryOK and TempearaturOK are executed at each tick()
+    // is Sequence is used and only once if SequenceStar is used.
+
+    for(auto& xml_text: {xml_text_sequence, xml_text_sequence_star})
+    {
+        std::cout << "\n------------ BUILDING A NEW TREE ------------\n\n" << std::endl;
+
+        auto tree = buildTreeFromText(factory, xml_text);
+        TreeNode::Ptr root_node = tree.first;
+
+        // This logger will show all the state transitions on console
+        StdCoutLogger logger_cout(root_node.get());
+
+        // This other logger will save the state transition in a custom file format
+        // simple_trace.fbl can be visualized using the command line tool [bt_log_cat]
+        FileLogger file_file(root_node.get(), "simple_trace.fbl", 32);
+
+        NodeStatus status;
+
+        std::cout << "\n------- First executeTick() --------" << std::endl;
+        status = root_node->executeTick();
+        Assert( status == NodeStatus::RUNNING);
+
+        std::cout << "\n------- sleep --------" << std::endl;
+        std::this_thread::sleep_for(std::chrono::milliseconds(50));
+
+        std::cout << "\n------- Second executeTick() --------" << std::endl;
+        status = root_node->executeTick();
+        Assert( status == NodeStatus::RUNNING);
+
+        std::cout << "\n------- sleep --------" << std::endl;
+        std::this_thread::sleep_for(std::chrono::milliseconds(50));
+
+        std::cout << "\n------- Third executeTick() --------" << std::endl;
+        status = root_node->executeTick();
+        Assert( status == NodeStatus::SUCCESS);
+
+        std::cout << std::endl;
+
+        // The main difference that you should notice is that the
+        // actions BatteryOK and TempearaturOK are executed at each tick()
+        // is Sequence is used and only once if SequenceStar is used.
+    }
+    return 0;
+}

examples/tutorial_sequence_star.cpp

@@ -43,7 +43,7 @@ const std::string xml_text = R"(
 
 // clang-format on
 
-int main(int argc, char** argv)
+int main()
 {
     using namespace BT;
 

gtest/crossdoor_example.cpp

@@ -18,36 +18,18 @@ namespace BT
 
 class StdCoutLogger : public StatusChangeLogger
 {
+    static std::atomic<bool> ref_count;
+
   public:
-    StdCoutLogger(TreeNode* root_node) : StatusChangeLogger(root_node)
-    {
-        static bool first_instance = true;
-        if (first_instance)
-        {
-            first_instance = false;
-        }
-        else
-        {
-            throw std::logic_error("Only one instance of StdCoutLogger shall be created");
-        }
-    }
-
-    virtual void callback(TimePoint timestamp, const TreeNode& node, NodeStatus prev_status, NodeStatus status) override
-    {
-        using namespace std::chrono;
-
-        constexpr const char* whitespaces = "                         ";
-        constexpr const size_t ws_count = 25;
-
-        double since_epoch = duration<double>(timestamp.time_since_epoch()).count();
-        printf("[%.3f]: %s%s %s -> %s\n", since_epoch, node.name().c_str(),
-               &whitespaces[std::min(ws_count, node.name().size())], toStr(prev_status, true), toStr(status, true));
-    }
-
-    virtual void flush() override
-    {
-        std::cout << std::flush;
-    }
+    StdCoutLogger(TreeNode* root_node);
+    ~StdCoutLogger();
+
+    virtual void callback(TimePoint timestamp,
+                          const TreeNode& node,
+                          NodeStatus prev_status,
+                          NodeStatus status) override;
+
+    virtual void flush() override;
 };
 
 }   // end namespace