From 5632fa03aee5ef831f0b6eded1eb13b6236142dc Mon Sep 17 00:00:00 2001
From: Chris Lalancette <clalancette@openrobotics.org>
Date: Wed, 27 May 2020 20:48:26 +0000
Subject: [PATCH] Hold onto the rcl_{subscription,publisher}_t shared_ptr.

This keeps it from going out of scope while the executor
is still dealing with QoSEvents.

Signed-off-by: Chris Lalancette <clalancette@openrobotics.org>
---
 rclcpp/include/rclcpp/publisher_base.hpp    | 5 +++--
 rclcpp/include/rclcpp/qos_event.hpp         | 8 +++++---
 rclcpp/include/rclcpp/subscription_base.hpp | 5 +++--
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/rclcpp/include/rclcpp/publisher_base.hpp b/rclcpp/include/rclcpp/publisher_base.hpp
index 0afe29b..48ebfea 100644
--- a/rclcpp/include/rclcpp/publisher_base.hpp
+++ b/rclcpp/include/rclcpp/publisher_base.hpp
@@ -200,10 +200,11 @@ protected:
     const EventCallbackT & callback,
     const rcl_publisher_event_type_t event_type)
   {
-    auto handler = std::make_shared<QOSEventHandler<EventCallbackT>>(
+    auto handler = std::make_shared<QOSEventHandler<EventCallbackT,
+        std::shared_ptr<rcl_publisher_t>>>(
       callback,
       rcl_publisher_event_init,
-      publisher_handle_.get(),
+      publisher_handle_,
       event_type);
     event_handlers_.emplace_back(handler);
   }
diff --git a/rclcpp/include/rclcpp/qos_event.hpp b/rclcpp/include/rclcpp/qos_event.hpp
index ad011f8..a43d904 100644
--- a/rclcpp/include/rclcpp/qos_event.hpp
+++ b/rclcpp/include/rclcpp/qos_event.hpp
@@ -102,11 +102,11 @@ protected:
   size_t wait_set_event_index_;
 };
 
-template<typename EventCallbackT>
+template<typename EventCallbackT, typename ParentHandleT>
 class QOSEventHandler : public QOSEventHandlerBase
 {
 public:
-  template<typename InitFuncT, typename ParentHandleT, typename EventTypeEnum>
+  template<typename InitFuncT, typename EventTypeEnum>
   QOSEventHandler(
     const EventCallbackT & callback,
     InitFuncT init_func,
@@ -114,8 +114,9 @@ public:
     EventTypeEnum event_type)
   : event_callback_(callback)
   {
+    parent_handle_ = parent_handle;
     event_handle_ = rcl_get_zero_initialized_event();
-    rcl_ret_t ret = init_func(&event_handle_, parent_handle, event_type);
+    rcl_ret_t ret = init_func(&event_handle_, parent_handle.get(), event_type);
     if (ret != RCL_RET_OK) {
       if (ret == RCL_RET_UNSUPPORTED) {
         UnsupportedEventTypeException exc(ret, rcl_get_error_state(), "Failed to initialize event");
@@ -148,6 +149,7 @@ private:
   using EventCallbackInfoT = typename std::remove_reference<typename
       rclcpp::function_traits::function_traits<EventCallbackT>::template argument_type<0>>::type;
 
+  ParentHandleT parent_handle_;
   EventCallbackT event_callback_;
 };
 
diff --git a/rclcpp/include/rclcpp/subscription_base.hpp b/rclcpp/include/rclcpp/subscription_base.hpp
index 84bb127..cb560d6 100644
--- a/rclcpp/include/rclcpp/subscription_base.hpp
+++ b/rclcpp/include/rclcpp/subscription_base.hpp
@@ -270,10 +270,11 @@ protected:
     const EventCallbackT & callback,
     const rcl_subscription_event_type_t event_type)
   {
-    auto handler = std::make_shared<QOSEventHandler<EventCallbackT>>(
+    auto handler = std::make_shared<QOSEventHandler<EventCallbackT,
+        std::shared_ptr<rcl_subscription_t>>>(
       callback,
       rcl_subscription_event_init,
-      get_subscription_handle().get(),
+      get_subscription_handle(),
       event_type);
     qos_events_in_use_by_wait_set_.insert(std::make_pair(handler.get(), false));
     event_handlers_.emplace_back(handler);