Merge pull request #125 from mauropasse/mauro/galactic-ev-ex-cherry-p…

…ick-1741

Galactic: for_each_callback_group backport (ros2#1741)

rclcpp/include/rclcpp/node.hpp

@@ -153,6 +153,17 @@ class Node : public std::enable_shared_from_this<Node>
   const std::vector<rclcpp::CallbackGroup::WeakPtr> &
   get_callback_groups() const;
 
+  /// Iterate over the callback groups in the node, calling the given function on each valid one.
+  /**
+   * This method is called in a thread-safe way, and also makes sure to only call the given
+   * function on those items that are still valid.
+   *
+   * \param[in] func The callback function to call on each valid callback group.
+   */
+  RCLCPP_PUBLIC
+  void
+  for_each_callback_group(const node_interfaces::NodeBaseInterface::CallbackGroupFunction & func);
+
   /// Create and return a Publisher.
   /**
    * The rclcpp::QoS has several convenient constructors, including a

rclcpp/include/rclcpp/node_interfaces/node_base.hpp

@@ -19,9 +19,11 @@
 #include <memory>
 #include <mutex>
 #include <string>
+#include <unordered_map>
 #include <vector>
 
 #include "rcl/node.h"
+#include "rclcpp/callback_group.hpp"
 #include "rclcpp/context.hpp"
 #include "rclcpp/macros.hpp"
 #include "rclcpp/node_interfaces/node_base_interface.hpp"
@@ -32,12 +34,34 @@ namespace rclcpp
 namespace node_interfaces
 {
 
+RCLCPP_PUBLIC
+void global_for_each_callback_group(
+  NodeBaseInterface * node_base_interface,
+  const NodeBaseInterface::CallbackGroupFunction & func);
+
+// Class to hold the global map of mutexes
+class map_of_mutexes final
+{
+public:
+  // Methods need to be protected by internal mutex
+  void create_mutex_of_nodebase(const NodeBaseInterface * nodebase);
+  std::shared_ptr<std::mutex>
+  get_mutex_of_nodebase(const NodeBaseInterface * nodebase);
+  void delete_mutex_of_nodebase(const NodeBaseInterface * nodebase);
+
+private:
+  std::unordered_map<const NodeBaseInterface *, std::shared_ptr<std::mutex>> data_;
+  std::mutex internal_mutex_;
+};
+
 /// Implementation of the NodeBase part of the Node API.
 class NodeBase : public NodeBaseInterface
 {
 public:
   RCLCPP_SMART_PTR_ALIASES_ONLY(NodeBase)
 
+  static map_of_mutexes map_object;
+
   RCLCPP_PUBLIC
   NodeBase(
     const std::string & node_name,

rclcpp/include/rclcpp/node_interfaces/node_base_interface.hpp

@@ -39,6 +39,8 @@ class NodeBaseInterface
 public:
   RCLCPP_SMART_PTR_ALIASES_ONLY(NodeBaseInterface)
 
+  using CallbackGroupFunction = std::function<void (rclcpp::CallbackGroup::SharedPtr)>;
+
   RCLCPP_PUBLIC
   virtual
   ~NodeBaseInterface() = default;

rclcpp/src/rclcpp/executor.cpp

@@ -30,6 +30,7 @@
 #include "rclcpp/node.hpp"
 #include "rclcpp/scope_exit.hpp"
 #include "rclcpp/utilities.hpp"
+#include "rclcpp/node_interfaces/node_base.hpp"
 
 #include "rcutils/logging_macros.h"
 
@@ -177,14 +178,13 @@ Executor::add_callback_groups_from_nodes_associated_to_executor()
   for (auto & weak_node : weak_nodes_) {
     auto node = weak_node.lock();
     if (node) {
-      auto group_ptrs = node->get_callback_groups();
-      std::for_each(
-        group_ptrs.begin(), group_ptrs.end(),
-        [this, node](rclcpp::CallbackGroup::WeakPtr group_ptr)
+      rclcpp::node_interfaces::global_for_each_callback_group(
+        node.get(),
+        [this, node](rclcpp::CallbackGroup::SharedPtr shared_group_ptr)
         {
-          auto shared_group_ptr = group_ptr.lock();
-          if (shared_group_ptr && shared_group_ptr->automatically_add_to_executor_with_node() &&
-          !shared_group_ptr->get_associated_with_executor_atomic().load())
+          if (
+            shared_group_ptr->automatically_add_to_executor_with_node() &&
+            !shared_group_ptr->get_associated_with_executor_atomic().load())
           {
             this->add_callback_group_to_map(
               shared_group_ptr,
@@ -263,18 +263,20 @@ Executor::add_node(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_pt
     throw std::runtime_error("Node has already been added to an executor.");
   }
   std::lock_guard<std::mutex> guard{mutex_};
-  for (auto & weak_group : node_ptr->get_callback_groups()) {
-    auto group_ptr = weak_group.lock();
-    if (group_ptr != nullptr && !group_ptr->get_associated_with_executor_atomic().load() &&
-      group_ptr->automatically_add_to_executor_with_node())
+  rclcpp::node_interfaces::global_for_each_callback_group(
+    node_ptr.get(),
+    [this, node_ptr, notify](rclcpp::CallbackGroup::SharedPtr group_ptr)
     {
-      this->add_callback_group_to_map(
-        group_ptr,
-        node_ptr,
-        weak_groups_to_nodes_associated_with_executor_,
-        notify);
-    }
-  }
+      if (!group_ptr->get_associated_with_executor_atomic().load() &&
+      group_ptr->automatically_add_to_executor_with_node())
+      {
+        this->add_callback_group_to_map(
+          group_ptr,
+          node_ptr,
+          weak_groups_to_nodes_associated_with_executor_,
+          notify);
+      }
+    });
 
   const auto & gc = node_ptr->get_notify_guard_condition();
   weak_nodes_to_guard_conditions_[node_ptr] = &gc;

rclcpp/src/rclcpp/executors/static_executor_entities_collector.cpp

@@ -24,6 +24,7 @@
 #include "rclcpp/memory_strategy.hpp"
 #include "rclcpp/executors/static_single_threaded_executor.hpp"
 #include "rclcpp/detail/add_guard_condition_to_rcl_wait_set.hpp"
+#include "rclcpp/node_interfaces/node_base.hpp"
 
 using rclcpp::executors::StaticExecutorEntitiesCollector;
 
@@ -288,18 +289,21 @@ StaticExecutorEntitiesCollector::add_node(
   if (has_executor.exchange(true)) {
     throw std::runtime_error("Node has already been added to an executor.");
   }
-  for (const auto & weak_group : node_ptr->get_callback_groups()) {
-    auto group_ptr = weak_group.lock();
-    if (group_ptr != nullptr && !group_ptr->get_associated_with_executor_atomic().load() &&
-      group_ptr->automatically_add_to_executor_with_node())
+  rclcpp::node_interfaces::global_for_each_callback_group(
+    node_ptr.get(),
+    [this, node_ptr, &is_new_node](rclcpp::CallbackGroup::SharedPtr group_ptr)
     {
-      is_new_node = (add_callback_group(
+      if (
+        !group_ptr->get_associated_with_executor_atomic().load() &&
+        group_ptr->automatically_add_to_executor_with_node())
+      {
+        is_new_node = (add_callback_group(
           group_ptr,
           node_ptr,
           weak_groups_to_nodes_associated_with_executor_) ||
         is_new_node);
-    }
-  }
+      }
+    });
   weak_nodes_.push_back(node_ptr);
   return is_new_node;
 }
@@ -467,13 +471,11 @@ StaticExecutorEntitiesCollector::add_callback_groups_from_nodes_associated_to_ex
   for (const auto & weak_node : weak_nodes_) {
     auto node = weak_node.lock();
     if (node) {
-      auto group_ptrs = node->get_callback_groups();
-      std::for_each(
-        group_ptrs.begin(), group_ptrs.end(),
-        [this, node](rclcpp::CallbackGroup::WeakPtr group_ptr)
+      rclcpp::node_interfaces::global_for_each_callback_group(
+        node.get(),
+        [this, node](rclcpp::CallbackGroup::SharedPtr shared_group_ptr)
         {
-          auto shared_group_ptr = group_ptr.lock();
-          if (shared_group_ptr && shared_group_ptr->automatically_add_to_executor_with_node() &&
+          if (shared_group_ptr->automatically_add_to_executor_with_node() &&
           !shared_group_ptr->get_associated_with_executor_atomic().load())
           {
             add_callback_group(

rclcpp/src/rclcpp/node.cpp

@@ -605,3 +605,9 @@ Node::get_node_options() const
 {
   return this->node_options_;
 }
+
+void Node::for_each_callback_group(
+  const node_interfaces::NodeBaseInterface::CallbackGroupFunction & func)
+{
+  rclcpp::node_interfaces::global_for_each_callback_group(node_base_.get(), func);
+}

rclcpp/src/rclcpp/node_interfaces/node_base.cpp

@@ -119,6 +119,8 @@ class NodeHandleWithContext
 };
 }  // anonymous namespace
 
+using rclcpp::node_interfaces::map_of_mutexes;
+
 NodeBase::NodeBase(
   const std::string & node_name,
   const std::string & namespace_,
@@ -135,6 +137,9 @@ NodeBase::NodeBase(
   notify_guard_condition_(context),
   notify_guard_condition_is_valid_(false)
 {
+  // Generate a mutex for this instance of NodeBase
+  NodeBase::map_object.create_mutex_of_nodebase(this);
+
   // Create the rcl node and store it in a shared_ptr with a custom destructor.
   std::unique_ptr<rcl_node_t> rcl_node(new rcl_node_t(rcl_get_zero_initialized_node()));
 
@@ -218,6 +223,8 @@ NodeBase::~NodeBase()
     std::lock_guard<std::recursive_mutex> notify_condition_lock(notify_guard_condition_mutex_);
     notify_guard_condition_is_valid_ = false;
   }
+
+  NodeBase::map_object.delete_mutex_of_nodebase(this);
 }
 
 const char *
@@ -273,12 +280,11 @@ NodeBase::create_callback_group(
   rclcpp::CallbackGroupType group_type,
   bool automatically_add_to_executor_with_node)
 {
-  using rclcpp::CallbackGroup;
-  using rclcpp::CallbackGroupType;
-  auto group = CallbackGroup::SharedPtr(
-    new CallbackGroup(
-      group_type,
-      automatically_add_to_executor_with_node));
+  auto group = std::make_shared<rclcpp::CallbackGroup>(
+    group_type,
+    automatically_add_to_executor_with_node);
+  auto mutex_ptr = NodeBase::map_object.get_mutex_of_nodebase(this);
+  std::lock_guard<std::mutex> lock(*mutex_ptr);
   callback_groups_.push_back(group);
   return group;
 }
@@ -292,14 +298,16 @@ NodeBase::get_default_callback_group()
 bool
 NodeBase::callback_group_in_node(rclcpp::CallbackGroup::SharedPtr group)
 {
-  bool group_belongs_to_this_node = false;
+  auto mutex_ptr = NodeBase::map_object.get_mutex_of_nodebase(this);
+  std::lock_guard<std::mutex> lock(*mutex_ptr);
+
   for (auto & weak_group : this->callback_groups_) {
     auto cur_group = weak_group.lock();
     if (cur_group && (cur_group == group)) {
-      group_belongs_to_this_node = true;
+      return true;
     }
   }
-  return group_belongs_to_this_node;
+  return false;
 }
 
 const std::vector<rclcpp::CallbackGroup::WeakPtr> &
@@ -362,3 +370,41 @@ NodeBase::trigger_notify_guard_condition()
 {
   notify_guard_condition_.trigger();
 }
+
+map_of_mutexes NodeBase::map_object = map_of_mutexes();
+
+void map_of_mutexes::create_mutex_of_nodebase(
+  const rclcpp::node_interfaces::NodeBaseInterface * nodebase)
+{
+  std::lock_guard<std::mutex> guard(this->internal_mutex_);
+  this->data_.emplace(nodebase, std::make_shared<std::mutex>() );
+}
+
+std::shared_ptr<std::mutex> map_of_mutexes::get_mutex_of_nodebase(
+  const rclcpp::node_interfaces::NodeBaseInterface * nodebase)
+{
+  std::lock_guard<std::mutex> guard(this->internal_mutex_);
+  return this->data_[nodebase];
+}
+
+void map_of_mutexes::delete_mutex_of_nodebase(
+  const rclcpp::node_interfaces::NodeBaseInterface * nodebase)
+{
+  std::lock_guard<std::mutex> guard(this->internal_mutex_);
+  this->data_.erase(nodebase);
+}
+
+// For each callback group free function implementation
+void rclcpp::node_interfaces::global_for_each_callback_group(
+  NodeBaseInterface * node_base_interface, const NodeBaseInterface::CallbackGroupFunction & func)
+{
+  auto mutex_ptr = NodeBase::map_object.get_mutex_of_nodebase(node_base_interface);
+  std::lock_guard<std::mutex> lock(*mutex_ptr);
+
+  for (const auto & weak_group : node_base_interface->get_callback_groups()) {
+    auto group = weak_group.lock();
+    if (group) {
+      func(group);
+    }
+  }
+}

rclcpp/test/rclcpp/executors/test_static_executor_entities_collector.cpp

@@ -41,38 +41,38 @@ struct NumberOfEntities
 std::unique_ptr<NumberOfEntities> get_number_of_default_entities(rclcpp::Node::SharedPtr node)
 {
   auto number_of_entities = std::make_unique<NumberOfEntities>();
-  for (auto & weak_group : node->get_callback_groups()) {
-    auto group = weak_group.lock();
-    EXPECT_NE(nullptr, group);
-    if (!group || !group->can_be_taken_from().load()) {
-      return nullptr;
-    }
-    group->find_subscription_ptrs_if(
-      [&number_of_entities](rclcpp::SubscriptionBase::SharedPtr &)
-      {
-        number_of_entities->subscriptions++; return false;
-      });
-    group->find_timer_ptrs_if(
-      [&number_of_entities](rclcpp::TimerBase::SharedPtr &)
-      {
-        number_of_entities->timers++; return false;
-      });
-    group->find_service_ptrs_if(
-      [&number_of_entities](rclcpp::ServiceBase::SharedPtr &)
-      {
-        number_of_entities->services++; return false;
-      });
-    group->find_client_ptrs_if(
-      [&number_of_entities](rclcpp::ClientBase::SharedPtr &)
-      {
-        number_of_entities->clients++; return false;
-      });
-    group->find_waitable_ptrs_if(
-      [&number_of_entities](rclcpp::Waitable::SharedPtr &)
-      {
-        number_of_entities->waitables++; return false;
-      });
-  }
+  node->for_each_callback_group(
+    [&number_of_entities](rclcpp::CallbackGroup::SharedPtr group)
+    {
+      if (!group->can_be_taken_from().load()) {
+        return;
+      }
+      group->find_subscription_ptrs_if(
+        [&number_of_entities](rclcpp::SubscriptionBase::SharedPtr &)
+        {
+          number_of_entities->subscriptions++; return false;
+        });
+      group->find_timer_ptrs_if(
+        [&number_of_entities](rclcpp::TimerBase::SharedPtr &)
+        {
+          number_of_entities->timers++; return false;
+        });
+      group->find_service_ptrs_if(
+        [&number_of_entities](rclcpp::ServiceBase::SharedPtr &)
+        {
+          number_of_entities->services++; return false;
+        });
+      group->find_client_ptrs_if(
+        [&number_of_entities](rclcpp::ClientBase::SharedPtr &)
+        {
+          number_of_entities->clients++; return false;
+        });
+      group->find_waitable_ptrs_if(
+        [&number_of_entities](rclcpp::Waitable::SharedPtr &)
+        {
+          number_of_entities->waitables++; return false;
+        });
+    });
 
   return number_of_entities;
 }