Ensure waitables handle guard condition retriggering (#2483)

Signed-off-by: William Woodall <[email protected]>
Signed-off-by: Michael Carroll <[email protected]>
Co-authored-by: Michael Carroll <[email protected]>

rclcpp/include/rclcpp/executors/executor_notify_waitable.hpp

@@ -50,7 +50,6 @@ class ExecutorNotifyWaitable : public rclcpp::Waitable
   RCLCPP_PUBLIC
   ExecutorNotifyWaitable(ExecutorNotifyWaitable & other);
 
-
   RCLCPP_PUBLIC
   ExecutorNotifyWaitable & operator=(ExecutorNotifyWaitable & other);
 

rclcpp/include/rclcpp/experimental/subscription_intra_process.hpp

@@ -101,6 +101,23 @@ class SubscriptionIntraProcess
 
   virtual ~SubscriptionIntraProcess() = default;
 
+  void
+  add_to_wait_set(rcl_wait_set_t & wait_set) override
+  {
+    // This block is necessary when the guard condition wakes the wait set, but
+    // the intra process waitable was not handled before the wait set is waited
+    // on again.
+    // Basically we're keeping the guard condition triggered so long as there is
+    // data in the buffer.
+    if (this->buffer_->has_data()) {
+      // If there is data still to be processed, indicate to the
+      // executor or waitset by triggering the guard condition.
+      this->trigger_guard_condition();
+    }
+    // Let the parent classes handle the rest of the work:
+    return SubscriptionIntraProcessBufferT::add_to_wait_set(wait_set);
+  }
+
   std::shared_ptr<void>
   take_data() override
   {
@@ -149,7 +166,7 @@ class SubscriptionIntraProcess
   typename std::enable_if<!std::is_same<T, rcl_serialized_message_t>::value, void>::type
   execute_impl(const std::shared_ptr<void> & data)
   {
-    if (!data) {
+    if (nullptr == data) {
       return;
     }
 

rclcpp/include/rclcpp/strategies/allocator_memory_strategy.hpp

@@ -17,7 +17,6 @@
 
 #include <memory>
 #include <vector>
-#include <utility>
 
 #include "rcl/allocator.h"
 
@@ -121,8 +120,8 @@ 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_triggered_handles_.emplace_back(std::move(waitable_handles_[i]));
+      if (!waitable_handles_[i]->is_ready(*wait_set)) {
+        waitable_handles_[i].reset();
       }
     }
 
@@ -146,7 +145,10 @@ class AllocatorMemoryStrategy : public memory_strategy::MemoryStrategy
       timer_handles_.end()
     );
 
-    waitable_handles_.clear();
+    waitable_handles_.erase(
+      std::remove(waitable_handles_.begin(), waitable_handles_.end(), nullptr),
+      waitable_handles_.end()
+    );
   }
 
   bool collect_entities(const WeakCallbackGroupsToNodesMap & weak_groups_to_nodes) override
@@ -390,17 +392,16 @@ class AllocatorMemoryStrategy : public memory_strategy::MemoryStrategy
     rclcpp::AnyExecutable & any_exec,
     const WeakCallbackGroupsToNodesMap & weak_groups_to_nodes) override
   {
-    auto & waitable_handles = waitable_triggered_handles_;
-    auto it = waitable_handles.begin();
-    while (it != waitable_handles.end()) {
+    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()) {
@@ -413,11 +414,11 @@ 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);
     }
   }
 
@@ -498,8 +499,6 @@ 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/src/rclcpp/event_handler.cpp

@@ -15,6 +15,7 @@
 #include <stdexcept>
 #include <string>
 
+#include "rcl/error_handling.h"
 #include "rcl/event.h"
 
 #include "rclcpp/event_handler.hpp"

rclcpp/src/rclcpp/executors/executor_notify_waitable.cpp

@@ -48,6 +48,11 @@ void
 ExecutorNotifyWaitable::add_to_wait_set(rcl_wait_set_t & wait_set)
 {
   std::lock_guard<std::mutex> lock(guard_condition_mutex_);
+
+  // Note: no guard conditions need to be re-triggered, since the guard
+  // conditions in this class are not tracking a stateful condition, but instead
+  // only serve to interrupt the wait set when new information is available to
+  // consider.
   for (auto weak_guard_condition : this->notify_guard_conditions_) {
     auto guard_condition = weak_guard_condition.lock();
     if (!guard_condition) {continue;}

rclcpp/test/rclcpp/CMakeLists.txt

@@ -566,6 +566,11 @@ if(TARGET test_thread_safe_synchronization)
   target_link_libraries(test_thread_safe_synchronization ${PROJECT_NAME} ${test_msgs_TARGETS})
 endif()
 
+ament_add_gtest(test_intra_process_waitable waitables/test_intra_process_waitable.cpp)
+if(TARGET test_intra_process_waitable)
+  target_link_libraries(test_intra_process_waitable ${PROJECT_NAME} ${test_msgs_TARGETS})
+endif()
+
 ament_add_gtest(test_rosout_qos test_rosout_qos.cpp)
 if(TARGET test_rosout_qos)
   target_link_libraries(test_rosout_qos ${PROJECT_NAME} rcl::rcl rmw::rmw)

rclcpp/test/rclcpp/strategies/test_allocator_memory_strategy.cpp

@@ -60,57 +60,6 @@ class TestWaitable : public rclcpp::Waitable
   void execute(const std::shared_ptr<void> &) override {}
 };
 
-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(const rcl_wait_set_t &) override
-  {
-    return test_waitable_result2;
-  }
-
-  std::shared_ptr<void>
-  take_data() override
-  {
-    return nullptr;
-  }
-
-  void execute(const 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;
@@ -705,129 +654,20 @@ 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;
     };
 
-  {
-    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);
-  }
+  EXPECT_TRUE(TestGetNextEntity(node1, node2, get_next_entity));
 }
 
 TEST_F(TestAllocatorMemoryStrategy, get_next_subscription_mutually_exclusive) {

rclcpp/test/rclcpp/test_memory_strategy.cpp

@@ -37,6 +37,7 @@ class TestWaitable : public rclcpp::Waitable
 public:
   void add_to_wait_set(rcl_wait_set_t &) override {}
   bool is_ready(const rcl_wait_set_t &) override {return true;}
+
   std::shared_ptr<void> take_data() override {return nullptr;}
   void execute(const std::shared_ptr<void> &) override {}
 };

rclcpp/test/rclcpp/wait_set_policies/test_static_storage.cpp

@@ -50,6 +50,7 @@ class TestWaitable : public rclcpp::Waitable
 public:
   TestWaitable()
   : is_ready_(false) {}
+
   void add_to_wait_set(rcl_wait_set_t &) override {}
 
   bool is_ready(const rcl_wait_set_t &) override {return is_ready_;}

rclcpp/test/rclcpp/wait_set_policies/test_storage_policy_common.cpp

@@ -50,6 +50,7 @@ class TestWaitable : public rclcpp::Waitable
 public:
   TestWaitable()
   : is_ready_(false), add_to_wait_set_(false) {}
+
   void add_to_wait_set(rcl_wait_set_t &) override
   {
     if (!add_to_wait_set_) {

rclcpp/test/rclcpp/wait_set_policies/test_thread_safe_synchronization.cpp

@@ -50,6 +50,7 @@ class TestWaitable : public rclcpp::Waitable
 public:
   TestWaitable()
   : is_ready_(false) {}
+
   void add_to_wait_set(rcl_wait_set_t &) override {}
 
   bool is_ready(const rcl_wait_set_t &) override {return is_ready_;}