Avoid losing waitable handles while using MultiThreadedExecutor (ros2#2109)

Signed-off-by: Barry Xu <[email protected]>

Author: Barry-Xu-2018

rclcpp/include/rclcpp/strategies/allocator_memory_strategy.hpp

@@ -17,6 +17,7 @@
 
 #include <memory>
 #include <vector>
+#include <utility>
 
 #include "rcl/allocator.h"
 
@@ -120,8 +121,8 @@ class AllocatorMemoryStrategy : public memory_strategy::MemoryStrategy
       }
     }
     for (size_t i = 0; i < waitable_handles_.size(); ++i) {
-      if (!waitable_handles_[i]->is_ready(wait_set)) {
-        waitable_handles_[i].reset();
+      if (waitable_handles_[i]->is_ready(wait_set)) {
+        waitable_triggered_handles_.emplace_back(std::move(waitable_handles_[i]));
       }
     }
 
@@ -145,10 +146,7 @@ class AllocatorMemoryStrategy : public memory_strategy::MemoryStrategy
       timer_handles_.end()
     );
 
-    waitable_handles_.erase(
-      std::remove(waitable_handles_.begin(), waitable_handles_.end(), nullptr),
-      waitable_handles_.end()
-    );
+    waitable_handles_.clear();
   }
 
   bool collect_entities(const WeakCallbackGroupsToNodesMap & weak_groups_to_nodes) override
@@ -392,16 +390,17 @@ class AllocatorMemoryStrategy : public memory_strategy::MemoryStrategy
     rclcpp::AnyExecutable & any_exec,
     const WeakCallbackGroupsToNodesMap & weak_groups_to_nodes) override
   {
-    auto it = waitable_handles_.begin();
-    while (it != waitable_handles_.end()) {
+    auto & waitable_handles = waitable_triggered_handles_;
+    auto it = waitable_handles.begin();
+    while (it != waitable_handles.end()) {
       std::shared_ptr<Waitable> & waitable = *it;
       if (waitable) {
         // Find the group for this handle and see if it can be serviced
         auto group = get_group_by_waitable(waitable, weak_groups_to_nodes);
         if (!group) {
           // Group was not found, meaning the waitable is not valid...
           // Remove it from the ready list and continue looking
-          it = waitable_handles_.erase(it);
+          it = waitable_handles.erase(it);
           continue;
         }
         if (!group->can_be_taken_from().load()) {
@@ -414,11 +413,11 @@ class AllocatorMemoryStrategy : public memory_strategy::MemoryStrategy
         any_exec.waitable = waitable;
         any_exec.callback_group = group;
         any_exec.node_base = get_node_by_group(group, weak_groups_to_nodes);
-        waitable_handles_.erase(it);
+        waitable_handles.erase(it);
         return;
       }
       // Else, the waitable is no longer valid, remove it and continue
-      it = waitable_handles_.erase(it);
+      it = waitable_handles.erase(it);
     }
   }
 
@@ -499,6 +498,8 @@ class AllocatorMemoryStrategy : public memory_strategy::MemoryStrategy
   VectorRebind<std::shared_ptr<const rcl_timer_t>> timer_handles_;
   VectorRebind<std::shared_ptr<Waitable>> waitable_handles_;
 
+  VectorRebind<std::shared_ptr<Waitable>> waitable_triggered_handles_;
+
   std::shared_ptr<VoidAlloc> allocator_;
 };
 

rclcpp/test/rclcpp/strategies/test_allocator_memory_strategy.cpp

@@ -63,6 +63,57 @@ class TestWaitable : public rclcpp::Waitable
   }
 };
 
+static bool test_waitable_result2 = false;
+
+class TestWaitable2 : public rclcpp::Waitable
+{
+public:
+  explicit TestWaitable2(rcl_publisher_t * pub_ptr)
+  : pub_ptr_(pub_ptr),
+    pub_event_(rcl_get_zero_initialized_event())
+  {
+    EXPECT_EQ(
+      rcl_publisher_event_init(&pub_event_, pub_ptr_, RCL_PUBLISHER_OFFERED_DEADLINE_MISSED),
+      RCL_RET_OK);
+  }
+
+  ~TestWaitable2()
+  {
+    EXPECT_EQ(rcl_event_fini(&pub_event_), RCL_RET_OK);
+  }
+
+  void add_to_wait_set(rcl_wait_set_t * wait_set) override
+  {
+    EXPECT_EQ(rcl_wait_set_add_event(wait_set, &pub_event_, &wait_set_event_index_), RCL_RET_OK);
+  }
+
+  bool is_ready(rcl_wait_set_t *) override
+  {
+    return test_waitable_result2;
+  }
+
+  std::shared_ptr<void>
+  take_data() override
+  {
+    return nullptr;
+  }
+
+  void execute(std::shared_ptr<void> & data) override
+  {
+    (void) data;
+  }
+
+  size_t get_number_of_ready_events() override
+  {
+    return 1;
+  }
+
+private:
+  rcl_publisher_t * pub_ptr_;
+  rcl_event_t pub_event_;
+  size_t wait_set_event_index_;
+};
+
 struct RclWaitSetSizes
 {
   size_t size_of_subscriptions = 0;
@@ -657,20 +708,129 @@ TEST_F(TestAllocatorMemoryStrategy, get_next_timer) {
 }
 
 TEST_F(TestAllocatorMemoryStrategy, get_next_waitable) {
-  auto node1 = std::make_shared<rclcpp::Node>("waitable_node", "ns");
-  auto node2 = std::make_shared<rclcpp::Node>("waitable_node2", "ns");
-  rclcpp::Waitable::SharedPtr waitable1 = std::make_shared<TestWaitable>();
-  rclcpp::Waitable::SharedPtr waitable2 = std::make_shared<TestWaitable>();
-  node1->get_node_waitables_interface()->add_waitable(waitable1, nullptr);
-  node2->get_node_waitables_interface()->add_waitable(waitable2, nullptr);
-
   auto get_next_entity = [this](const WeakCallbackGroupsToNodesMap & weak_groups_to_nodes) {
       rclcpp::AnyExecutable result;
       allocator_memory_strategy()->get_next_waitable(result, weak_groups_to_nodes);
       return result;
     };
 
-  EXPECT_TRUE(TestGetNextEntity(node1, node2, get_next_entity));
+  {
+    auto node1 = std::make_shared<rclcpp::Node>(
+      "waitable_node", "ns",
+      rclcpp::NodeOptions()
+      .start_parameter_event_publisher(false)
+      .start_parameter_services(false));
+
+    rclcpp::PublisherOptions pub_options;
+    pub_options.use_default_callbacks = false;
+
+    auto pub1 = node1->create_publisher<test_msgs::msg::Empty>(
+      "test_topic_1", rclcpp::QoS(10), pub_options);
+
+    auto waitable1 =
+      std::make_shared<TestWaitable2>(pub1->get_publisher_handle().get());
+    node1->get_node_waitables_interface()->add_waitable(waitable1, nullptr);
+
+    auto basic_node = create_node_with_disabled_callback_groups("basic_node");
+    WeakCallbackGroupsToNodesMap weak_groups_to_nodes;
+    basic_node->for_each_callback_group(
+      [basic_node, &weak_groups_to_nodes](rclcpp::CallbackGroup::SharedPtr group_ptr)
+      {
+        weak_groups_to_nodes.insert(
+          std::pair<rclcpp::CallbackGroup::WeakPtr,
+          rclcpp::node_interfaces::NodeBaseInterface::WeakPtr>(
+            group_ptr,
+            basic_node->get_node_base_interface()));
+      });
+    node1->for_each_callback_group(
+      [node1, &weak_groups_to_nodes](rclcpp::CallbackGroup::SharedPtr group_ptr)
+      {
+        weak_groups_to_nodes.insert(
+          std::pair<rclcpp::CallbackGroup::WeakPtr,
+          rclcpp::node_interfaces::NodeBaseInterface::WeakPtr>(
+            group_ptr,
+            node1->get_node_base_interface()));
+      });
+    allocator_memory_strategy()->collect_entities(weak_groups_to_nodes);
+
+    rcl_wait_set_t wait_set = rcl_get_zero_initialized_wait_set();
+    ASSERT_EQ(
+      rcl_wait_set_init(
+        &wait_set,
+        allocator_memory_strategy()->number_of_ready_subscriptions(),
+        allocator_memory_strategy()->number_of_guard_conditions(),
+        allocator_memory_strategy()->number_of_ready_timers(),
+        allocator_memory_strategy()->number_of_ready_clients(),
+        allocator_memory_strategy()->number_of_ready_services(),
+        allocator_memory_strategy()->number_of_ready_events(),
+        rclcpp::contexts::get_global_default_context()->get_rcl_context().get(),
+        allocator_memory_strategy()->get_allocator()),
+      RCL_RET_OK);
+
+    ASSERT_TRUE(allocator_memory_strategy()->add_handles_to_wait_set(&wait_set));
+
+    ASSERT_EQ(
+      rcl_wait(
+        &wait_set,
+        std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::milliseconds(100))
+        .count()),
+      RCL_RET_OK);
+    test_waitable_result2 = true;
+    allocator_memory_strategy()->remove_null_handles(&wait_set);
+
+    rclcpp::AnyExecutable result = get_next_entity(weak_groups_to_nodes);
+    EXPECT_EQ(result.node_base, node1->get_node_base_interface());
+    test_waitable_result2 = false;
+
+    EXPECT_EQ(rcl_wait_set_fini(&wait_set), RCL_RET_OK);
+  }
+
+  {
+    auto node2 = std::make_shared<rclcpp::Node>(
+      "waitable_node2", "ns",
+      rclcpp::NodeOptions()
+      .start_parameter_services(false)
+      .start_parameter_event_publisher(false));
+
+    rclcpp::PublisherOptions pub_options;
+    pub_options.use_default_callbacks = false;
+
+    auto pub2 = node2->create_publisher<test_msgs::msg::Empty>(
+      "test_topic_2", rclcpp::QoS(10), pub_options);
+
+    auto waitable2 =
+      std::make_shared<TestWaitable2>(pub2->get_publisher_handle().get());
+    node2->get_node_waitables_interface()->add_waitable(waitable2, nullptr);
+
+    auto basic_node2 = std::make_shared<rclcpp::Node>(
+      "basic_node2", "ns",
+      rclcpp::NodeOptions()
+      .start_parameter_services(false)
+      .start_parameter_event_publisher(false));
+    WeakCallbackGroupsToNodesMap weak_groups_to_uncollected_nodes;
+    basic_node2->for_each_callback_group(
+      [basic_node2, &weak_groups_to_uncollected_nodes](rclcpp::CallbackGroup::SharedPtr group_ptr)
+      {
+        weak_groups_to_uncollected_nodes.insert(
+          std::pair<rclcpp::CallbackGroup::WeakPtr,
+          rclcpp::node_interfaces::NodeBaseInterface::WeakPtr>(
+            group_ptr,
+            basic_node2->get_node_base_interface()));
+      });
+    node2->for_each_callback_group(
+      [node2,
+      &weak_groups_to_uncollected_nodes](rclcpp::CallbackGroup::SharedPtr group_ptr)
+      {
+        weak_groups_to_uncollected_nodes.insert(
+          std::pair<rclcpp::CallbackGroup::WeakPtr,
+          rclcpp::node_interfaces::NodeBaseInterface::WeakPtr>(
+            group_ptr,
+            node2->get_node_base_interface()));
+      });
+
+    rclcpp::AnyExecutable failed_result = get_next_entity(weak_groups_to_uncollected_nodes);
+    EXPECT_EQ(failed_result.node_base, nullptr);
+  }
 }
 
 TEST_F(TestAllocatorMemoryStrategy, get_next_subscription_mutually_exclusive) {