Add support for guard conditions

rcldotnet/CMakeLists.txt

@@ -29,13 +29,15 @@ set(CSHARP_TARGET_FRAMEWORK "netstandard2.0")
 
 set(CS_SOURCES
   Client.cs
+  GuardCondition.cs
   MessageStaticMemberCache.cs
   Node.cs
   Publisher.cs
   RCLdotnet.cs
   RCLExceptionHelper.cs
   RCLRet.cs
   SafeClientHandle.cs
+  SafeGuardConditionHandle.cs
   SafeNodeHandle.cs
   SafePublisherHandle.cs
   SafeRequestIdHandle.cs
@@ -62,29 +64,28 @@ add_dotnet_library(${PROJECT_NAME}_assemblies
 install_dotnet(${PROJECT_NAME}_assemblies DESTINATION lib/${PROJECT_NAME}/dotnet)
 ament_export_assemblies_dll("lib/${PROJECT_NAME}/dotnet/${PROJECT_NAME}_assemblies.dll")
 
-set(_native_sources "rcldotnet;rcldotnet_node;rcldotnet_publisher;rcldotnet_client")
+add_library(${PROJECT_NAME}_native SHARED
+  rcldotnet_client.c
+  rcldotnet_guard_condition.c
+  rcldotnet_node.c
+  rcldotnet_publisher.c
+  rcldotnet.c
+)
 
-foreach(_target_name ${_native_sources})
-  add_library(${_target_name} SHARED
-    ${_target_name}.c
-  )
-  set_target_properties(${_target_name}
-    PROPERTIES
-    OUTPUT_NAME ${_target_name}_native)
-  ament_target_dependencies(${_target_name}
-    "builtin_interfaces"
-    "rcl"
-    "rosidl_generator_c"
-    "rosidl_typesupport_c"
-  )
-  ament_export_libraries(${_target_name}_native)
+ament_target_dependencies(${PROJECT_NAME}_native
+  "builtin_interfaces"
+  "rcl"
+  "rosidl_generator_c"
+  "rosidl_typesupport_c"
+)
 
-  install(TARGETS ${_target_name}
-    ARCHIVE DESTINATION lib
-    LIBRARY DESTINATION lib
-    RUNTIME DESTINATION bin
-  )
-endforeach()
+ament_export_libraries(${PROJECT_NAME}_native)
+
+install(TARGETS ${PROJECT_NAME}_native
+  ARCHIVE DESTINATION lib
+  LIBRARY DESTINATION lib
+  RUNTIME DESTINATION bin
+)
 
 ament_export_dependencies(ament_cmake)
 ament_export_dependencies(builtin_interfaces)
@@ -120,6 +121,7 @@ if(BUILD_TESTING)
     ${RCLDOTNET_TEST_TARGET_FRAMEWORK}
     SOURCES
     ${CS_SOURCES}
+    test/test_guard_conditions.cs
     test/test_messages.cs
     test/test_services.cs
     INCLUDE_DLLS

rcldotnet/Client.cs

@@ -40,7 +40,7 @@ internal delegate RCLRet NativeRCLServiceServerIsAvailableType(
         static ClientDelegates()
         {
             _dllLoadUtils = DllLoadUtilsFactory.GetDllLoadUtils();
-            IntPtr nativeLibrary = _dllLoadUtils.LoadLibrary("rcldotnet_client");
+            IntPtr nativeLibrary = _dllLoadUtils.LoadLibrary("rcldotnet");
 
             IntPtr native_rcl_send_request_ptr = _dllLoadUtils.GetProcAddress(nativeLibrary, "native_rcl_send_request");
             ClientDelegates.native_rcl_send_request = (NativeRCLSendRequestType)Marshal.GetDelegateForFunctionPointer(

rcldotnet/GuardCondition.cs

@@ -0,0 +1,71 @@
+/* Copyright 2022 Stefan Hoffmann <stefan.hoffmann@schiller.de>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+using System;
+using System.Runtime.InteropServices;
+using ROS2.Utils;
+
+namespace ROS2
+{
+    internal static class GuardConditionDelegates
+    {
+        internal static readonly DllLoadUtils _dllLoadUtils;
+
+        [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
+        internal delegate RCLRet NativeRCLTriggerGuardConditionType(
+            SafeGuardConditionHandle guardConditionHandle);
+
+        internal static NativeRCLTriggerGuardConditionType native_rcl_trigger_guard_condition = null;
+
+        static GuardConditionDelegates()
+        {
+            _dllLoadUtils = DllLoadUtilsFactory.GetDllLoadUtils();
+            IntPtr nativeLibrary = _dllLoadUtils.LoadLibrary("rcldotnet");
+
+            IntPtr native_rcl_trigger_guard_condition_ptr = _dllLoadUtils.GetProcAddress(nativeLibrary, "native_rcl_trigger_guard_condition");
+            GuardConditionDelegates.native_rcl_trigger_guard_condition = (NativeRCLTriggerGuardConditionType)Marshal.GetDelegateForFunctionPointer(
+                native_rcl_trigger_guard_condition_ptr, typeof(NativeRCLTriggerGuardConditionType));
+        }
+    }
+
+    public sealed class GuardCondition
+    {
+        private readonly Action _callback;
+
+        internal GuardCondition(SafeGuardConditionHandle handle, Action callback)
+        {
+            Handle = handle;
+            _callback = callback;
+        }
+
+        // GuardCondition does intentionally (for now) not implement IDisposable as this
+        // needs some extra consideration how the type works after its
+        // internal handle is disposed.
+        // By relying on the GC/Finalizer of SafeHandle the handle only gets
+        // Disposed if the publisher is not live anymore.
+        internal SafeGuardConditionHandle Handle { get; }
+
+        public void Trigger()
+        {
+            RCLRet ret = GuardConditionDelegates.native_rcl_trigger_guard_condition(Handle);
+            RCLExceptionHelper.CheckReturnValue(ret, $"{nameof(GuardConditionDelegates.native_rcl_trigger_guard_condition)}() failed.");
+        }
+
+        internal void TriggerCallback()
+        {
+            _callback();
+        }
+    }
+}

rcldotnet/Node.cs

@@ -75,7 +75,7 @@ internal delegate RCLRet NativeRCLDestroyClientHandleType(
         static NodeDelegates()
         {
             _dllLoadUtils = DllLoadUtilsFactory.GetDllLoadUtils();
-            IntPtr nativeLibrary = _dllLoadUtils.LoadLibrary("rcldotnet_node");
+            IntPtr nativeLibrary = _dllLoadUtils.LoadLibrary("rcldotnet");
 
             IntPtr native_rcl_create_publisher_handle_ptr = _dllLoadUtils.GetProcAddress(
                 nativeLibrary, "native_rcl_create_publisher_handle");
@@ -137,19 +137,21 @@ static NodeDelegates()
 
     public sealed class Node
     {
-
         private readonly IList<Subscription> _subscriptions;
 
         private readonly IList<Service> _services;
 
         private readonly IList<Client> _clients;
 
+        private readonly IList<GuardCondition> _guardConditions;
+
         internal Node(SafeNodeHandle handle)
         {
             Handle = handle;
             _subscriptions = new List<Subscription>();
             _services = new List<Service>();
             _clients = new List<Client>();
+            _guardConditions = new List<GuardCondition>();
         }
 
         public IList<Subscription> Subscriptions => _subscriptions;
@@ -161,6 +163,8 @@ internal Node(SafeNodeHandle handle)
 
         public IList<Client> Clients => _clients;
 
+        public IList<GuardCondition> GuardConditions => _guardConditions;
+
         // Node does intentionaly (for now) not implement IDisposable as this
         // needs some extra consideration how the type works after its
         // internal handle is disposed.
@@ -248,5 +252,20 @@ public Client<TService, TRequest, TResponse> CreateClient<TService, TRequest, TR
             _clients.Add(client);
             return client;
         }
+
+        public GuardCondition CreateGuardCondition(Action callback)
+        {
+            var guardConditionHandle = new SafeGuardConditionHandle();
+            RCLRet ret = RCLdotnetDelegates.native_rcl_create_guard_condition_handle(ref guardConditionHandle);
+            if (ret != RCLRet.Ok)
+            {
+                guardConditionHandle.Dispose();
+                throw RCLExceptionHelper.CreateFromReturnValue(ret, $"{nameof(RCLdotnetDelegates.native_rcl_create_guard_condition_handle)}() failed.");
+            }
+
+            var guardCondition = new GuardCondition(guardConditionHandle, callback);
+            _guardConditions.Add(guardCondition);
+            return guardCondition;
+        }
     }
 }

rcldotnet/Publisher.cs

@@ -32,7 +32,7 @@ internal delegate RCLRet NativeRCLPublishType(
         static PublisherDelegates()
         {
             _dllLoadUtils = DllLoadUtilsFactory.GetDllLoadUtils();
-            IntPtr nativeLibrary = _dllLoadUtils.LoadLibrary("rcldotnet_publisher");
+            IntPtr nativeLibrary = _dllLoadUtils.LoadLibrary("rcldotnet");
 
             IntPtr native_rcl_publish_ptr = _dllLoadUtils.GetProcAddress(nativeLibrary, "native_rcl_publish");
             PublisherDelegates.native_rcl_publish = (NativeRCLPublishType)Marshal.GetDelegateForFunctionPointer(