Add publisher liveliness lost event

rcljava/CMakeLists.txt

@@ -60,6 +60,7 @@ set(${PROJECT_NAME}_jni_sources
   "src/main/cpp/org_ros2_rcljava_contexts_ContextImpl.cpp"
   "src/main/cpp/org_ros2_rcljava_executors_BaseExecutor.cpp"
   "src/main/cpp/org_ros2_rcljava_events_EventHandlerImpl.cpp"
+  "src/main/cpp/org_ros2_rcljava_events_publisher_statuses_LivelinessLost.cpp"
   "src/main/cpp/org_ros2_rcljava_node_NodeImpl.cpp"
   "src/main/cpp/org_ros2_rcljava_publisher_PublisherImpl.cpp"
   "src/main/cpp/org_ros2_rcljava_service_ServiceImpl.cpp"
@@ -129,6 +130,9 @@ set(${PROJECT_NAME}_sources
   "src/main/java/org/ros2/rcljava/events/EventHandler.java"
   "src/main/java/org/ros2/rcljava/events/EventHandlerImpl.java"
   "src/main/java/org/ros2/rcljava/events/EventStatus.java"
+  "src/main/java/org/ros2/rcljava/events/PublisherEventStatus.java"
+  "src/main/java/org/ros2/rcljava/events/SubscriptionEventStatus.java"
+  "src/main/java/org/ros2/rcljava/events/publisher_statuses/LivelinessLost.java"
   "src/main/java/org/ros2/rcljava/executors/AnyExecutable.java"
   "src/main/java/org/ros2/rcljava/executors/BaseExecutor.java"
   "src/main/java/org/ros2/rcljava/executors/Executor.java"

rcljava/include/org_ros2_rcljava_events_EventHandlerImpl.h

@@ -27,7 +27,8 @@ extern "C" {
  * Signature: (J)V
  */
 JNIEXPORT void
-JNICALL Java_org_ros2_rcljava_events_EventHandlerImpl_nativeDispose(JNIEnv *, jclass, jlong event_handle);
+JNICALL Java_org_ros2_rcljava_events_EventHandlerImpl_nativeDispose(
+  JNIEnv *, jclass, jlong event_handle);
 
 /*
  * Class:     org_ros2_rcljava_events_EventHandlerImpl

rcljava/include/org_ros2_rcljava_events_publisher_statuses_LivelinessLost.h

@@ -0,0 +1,63 @@
+// Copyright 2020 Open Source Robotics Foundation, Inc.
+//
+// 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.
+
+#include <jni.h>
+/* Header for class org_ros2_rcljava_events_publisher_statuses_LivelinessLost */
+
+#ifndef ORG_ROS2_RCLJAVA_EVENTS_PUBLISHER_STATUSES_LIVELINESSLOST_H_
+#define ORG_ROS2_RCLJAVA_EVENTS_PUBLISHER_STATUSES_LIVELINESSLOST_H_
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Class:     org_ros2_rcljava_events_publisher_statuses_LivelinessLost
+ * Method:    nativeAllocateRCLStatusEvent
+ * Signature: ()J
+ */
+JNIEXPORT jlong JNICALL
+Java_org_ros2_rcljava_events_publisher_1statuses_LivelinessLost_nativeAllocateRCLStatusEvent(
+  JNIEnv *, jclass);
+
+/*
+ * Class:     org_ros2_rcljava_events_publisher_statuses_LivelinessLost
+ * Method:    nativeDeallocateRCLStatusEvent
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL
+Java_org_ros2_rcljava_events_publisher_1statuses_LivelinessLost_nativeDeallocateRCLStatusEvent(
+  JNIEnv *, jclass, jlong);
+
+/*
+ * Class:     org_ros2_rcljava_events_publisher_statuses_LivelinessLost
+ * Method:    nativeFromRCLEvent
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL
+Java_org_ros2_rcljava_events_publisher_1statuses_LivelinessLost_nativeFromRCLEvent(
+  JNIEnv *, jobject, jlong);
+
+/*
+ * Class:     org_ros2_rcljava_events_publisher_statuses_LivelinessLost
+ * Method:    nativeGetPublisherEventType
+ * Signature: ()I
+ */
+JNIEXPORT jint JNICALL
+Java_org_ros2_rcljava_events_publisher_1statuses_LivelinessLost_nativeGetPublisherEventType(
+  JNIEnv *, jclass);
+
+#ifdef __cplusplus
+}
+#endif
+#endif  // ORG_ROS2_RCLJAVA_EVENTS_PUBLISHER_STATUSES_LIVELINESSLOST_H_

rcljava/include/org_ros2_rcljava_publisher_PublisherImpl.h

@@ -38,6 +38,15 @@ JNIEXPORT void
 JNICALL Java_org_ros2_rcljava_publisher_PublisherImpl_nativeDispose(
   JNIEnv *, jclass, jlong, jlong);
 
+/*
+ * Class:     org_ros2_rcljava_publisher_PublisherImpl
+ * Method:    nativeCreateEvent
+ * Signature: (JJ)J
+ */
+JNIEXPORT jlong
+JNICALL Java_org_ros2_rcljava_publisher_PublisherImpl_nativeCreateEvent(
+  JNIEnv *, jclass, jlong, jint);
+
 #ifdef __cplusplus
 }
 #endif

rcljava/src/main/cpp/org_ros2_rcljava_events_EventHandlerImpl.cpp

@@ -47,7 +47,8 @@ Java_org_ros2_rcljava_events_EventHandlerImpl_nativeDispose(
 }
 
 JNIEXPORT void JNICALL
-Java_org_ros2_rcljava_events_EventHandlerImpl_nativeTake(JNIEnv *env, jclass, jlong event_handle, jlong event_status_handle)
+Java_org_ros2_rcljava_events_EventHandlerImpl_nativeTake(
+  JNIEnv * env, jclass, jlong event_handle, jlong event_status_handle)
 {
   auto * event = reinterpret_cast<rcl_event_t *>(event_handle);
   if (!event) {

rcljava/src/main/cpp/org_ros2_rcljava_events_publisher_statuses_LivelinessLost.cpp

@@ -0,0 +1,73 @@
+// Copyright 2020 Open Source Robotics Foundation, Inc.
+//
+// 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.
+
+#include "org_ros2_rcljava_events_publisher_statuses_LivelinessLost.h"
+
+#include <jni.h>
+#include <stdlib.h>
+
+#include "rmw/events_statuses/liveliness_lost.h"
+#include "rcl/event.h"
+#include "rcljava_common/exceptions.hpp"
+
+using rcljava_common::exceptions::rcljava_throw_exception;
+
+JNIEXPORT jlong JNICALL
+Java_org_ros2_rcljava_events_publisher_1statuses_LivelinessLost_nativeAllocateRCLStatusEvent(
+  JNIEnv * env, jclass)
+{
+  void * p = malloc(sizeof(rmw_liveliness_lost_status_t));
+  if (!p) {
+    rcljava_throw_exception(
+      env, "java/lang/OutOfMemoryError", "failed to allocate liveliness lost status");
+  }
+  return reinterpret_cast<jlong>(p);
+}
+
+JNIEXPORT void JNICALL
+Java_org_ros2_rcljava_events_publisher_1statuses_LivelinessLost_nativeDeallocateRCLStatusEvent(
+  JNIEnv *, jclass, jlong handle)
+{
+  free(reinterpret_cast<void *>(handle));
+}
+
+JNIEXPORT void JNICALL
+Java_org_ros2_rcljava_events_publisher_1statuses_LivelinessLost_nativeFromRCLEvent(
+  JNIEnv * env, jobject self, jlong handle)
+{
+  auto * p = reinterpret_cast<rmw_liveliness_lost_status_t *>(handle);
+  if (!p) {
+    rcljava_throw_exception(
+      env, "java/lang/IllegalArgumentException", "passed rmw object handle is NULL");
+  }
+  // TODO(ivanpauno): class and field lookup could be done at startup time
+  jclass clazz = env->GetObjectClass(self);
+  jfieldID total_count_fid = env->GetFieldID(clazz, "total_count", "I");
+  if (env->ExceptionCheck()) {
+    return;
+  }
+  jfieldID total_count_change_fid = env->GetFieldID(clazz, "total_count_change", "I");
+  if (env->ExceptionCheck()) {
+    return;
+  }
+  env->SetIntField(self, total_count_fid, p->total_count);
+  env->SetIntField(self, total_count_change_fid, p->total_count_change);
+}
+
+JNIEXPORT jint JNICALL
+Java_org_ros2_rcljava_events_publisher_1statuses_LivelinessLost_nativeGetPublisherEventType(
+  JNIEnv *, jclass)
+{
+  return RCL_PUBLISHER_LIVELINESS_LOST;
+}

rcljava/src/main/cpp/org_ros2_rcljava_publisher_PublisherImpl.cpp

@@ -20,6 +20,7 @@
 #include <string>
 
 #include "rcl/error_handling.h"
+#include "rcl/event.h"
 #include "rcl/node.h"
 #include "rcl/rcl.h"
 #include "rmw/rmw.h"
@@ -29,6 +30,7 @@
 
 #include "org_ros2_rcljava_publisher_PublisherImpl.h"
 
+using rcljava_common::exceptions::rcljava_throw_exception;
 using rcljava_common::exceptions::rcljava_throw_rclexception;
 using rcljava_common::signatures::convert_from_java_signature;
 using rcljava_common::signatures::destroy_ros_message_signature;
@@ -90,3 +92,31 @@ Java_org_ros2_rcljava_publisher_PublisherImpl_nativeDispose(
     rcljava_throw_rclexception(env, ret, msg);
   }
 }
+
+JNIEXPORT jlong JNICALL
+Java_org_ros2_rcljava_publisher_PublisherImpl_nativeCreateEvent(
+  JNIEnv * env, jclass, jlong publisher_handle, jint event_type)
+{
+  auto * publisher = reinterpret_cast<rcl_publisher_t *>(publisher_handle);
+  if (!publisher) {
+    rcljava_throw_exception(
+      env, "java/lang/IllegalArgumentException", "passed rcl_publisher_t handle is NULL");
+    return 0;
+  }
+  auto * event = static_cast<rcl_event_t *>(malloc(sizeof(rcl_event_t)));
+  if (!event) {
+    rcljava_throw_exception(env, "java/lang/OutOfMemoryError", "failed to allocate rcl_event_t");
+    return 0;
+  }
+  *event = rcl_get_zero_initialized_event();
+  rcl_ret_t ret = rcl_publisher_event_init(
+    event, publisher, static_cast<rcl_publisher_event_type_t>(event_type));
+  if (RCL_RET_OK != ret) {
+    std::string msg = "Failed to create event: " + std::string(rcl_get_error_string().str);
+    rcl_reset_error();
+    rcljava_throw_rclexception(env, ret, msg);
+    free(event);
+    return 0;
+  }
+  return reinterpret_cast<jlong>(event);
+}

rcljava/src/main/java/org/ros2/rcljava/events/EventHandler.java

@@ -29,16 +29,6 @@
  * @param <ParentT> The parent class type.
  */
 public interface EventHandler<T extends EventStatus, ParentT extends Disposable> extends Disposable {
-  /**
-   * @return The event status type.
-   */
-  Class<T> getEventStatusType();
-
-  /**
-   * @return The parent entity type.
-   */
-  Class<ParentT> getParentType();
-
   /**
    * @return A weak reference to the parent.
    */

rcljava/src/main/java/org/ros2/rcljava/events/EventHandlerImpl.java

@@ -16,6 +16,7 @@
 
 import java.lang.ref.WeakReference;
 import java.lang.reflect.InvocationTargetException;
+import java.util.function.Supplier;
 
 import org.ros2.rcljava.common.JNIUtils;
 import org.ros2.rcljava.consumers.Consumer;
@@ -53,48 +54,28 @@ public class EventHandlerImpl<
   /**
    * Constructor.
    *
-   * @param parentType The <code>Class</code> type of the parent.
-   *    It can be either a @{link org.ros2.rcljava.Publisher} or a
-   *    @{link org.ros2.rcljava.Subscription} class.
    * @param parentReference A {@link java.lang.ref.WeakReference} to the
    *     @{link org.ros2.rcljava.Publisher} or @{link org.ros2.rcljava.Subscription}
    *     that created this event handler.
    * @param handle A pointer to the underlying ROS 2 event structure, as an integer.
    *     Must not be zero.
-   * @param eventStatusType The <code>Class</code> of the messages that this
-   *     subscription will receive. We need this because of Java's type erasure,
-   *     which doesn't allow us to use the generic parameter of
-   *     @{link org.ros2.rcljava.Subscription} directly.
+   *     Ownership of the passed `handle` is taken, and this object is responsible
+   *     of disposing it. That can be done using @{link EventHandler#dispose()}.
+   * @param eventStatusFactory Factory of an event status.
    * @param callback The callback function that will be called when the event
    *     is triggered.
    */
   public EventHandlerImpl(
-      final Class<ParentT> parentType,
       final WeakReference<ParentT> parentReference,
       final long handle,
-      final Class<T> eventStatusType,
+      final Supplier<T> eventStatusFactory,
       final Consumer<T> callback) {
-    this.parentType = parentType;
     this.parentReference = parentReference;
     this.handle = handle;
-    this.eventStatusType = eventStatusType;
+    this.eventStatusFactory = eventStatusFactory;
     this.callback = callback;
   }
 
-  /**
-   * {@inheritDoc}
-   */
-  public final Class<T> getEventStatusType() {
-    return this.eventStatusType;
-  }
-
-  /**
-   * {@inheritDoc}
-   */
-  public final Class<ParentT> getParentType() {
-    return this.parentType;
-  }
-
   /**
    * {@inheritDoc}
    */
@@ -120,8 +101,10 @@ public final long getHandle() {
   /**
    * {@inheritDoc}
    */
-  public final void dispose() {
-    nativeDispose(this.handle);
+  public synchronized final void dispose() {
+    if (this.handle != 0) {
+      nativeDispose(this.handle);
+    }
     this.handle = 0;
   }
 
@@ -137,28 +120,16 @@ public final void dispose() {
   /**
    * {@inheritDoc}
    */
-  public final void executeCallback() {
-    T eventStatus = null;
-    try {
-        eventStatus = this.eventStatusType.getDeclaredConstructor().newInstance();
-    } catch (NoSuchMethodException nme) {
-        nme.printStackTrace();
-    } catch (InvocationTargetException ite) {
-        ite.printStackTrace();
-    } catch (InstantiationException ie) {
-        ie.printStackTrace();
-    } catch (IllegalAccessException iae) {
-        iae.printStackTrace();
-    }
+  public synchronized final void executeCallback() {
+    T eventStatus = eventStatusFactory.get();
     long nativeEventStatusHandle = eventStatus.allocateRCLStatusEvent();
     nativeTake(this.handle, nativeEventStatusHandle);
     eventStatus.fromRCLEvent(nativeEventStatusHandle);
     eventStatus.deallocateRCLStatusEvent(nativeEventStatusHandle);
     callback.accept(eventStatus);
   }
 
-  private final Class<T> eventStatusType;
-  private final Class<ParentT> parentType;
+  private final Supplier<T> eventStatusFactory;
   private final WeakReference<ParentT> parentReference;
   private long handle;
   private final Consumer<T> callback;

rcljava/src/main/java/org/ros2/rcljava/events/PublisherEventStatus.java

@@ -24,5 +24,5 @@ public interface PublisherEventStatus extends EventStatus {
   /**
    * @return The status event type.
    */
-  int get_publisher_event_type();
+  int getPublisherEventType();
 }

rcljava/src/main/java/org/ros2/rcljava/events/SubscriptionEventStatus.java

@@ -24,5 +24,5 @@ public interface SubscriptionEventStatus extends EventStatus {
   /**
    * @return The status event type.
    */
-  int get_subscription_event_type();
+  int getSubscriptionEventType();
 }