diff --git a/rmw_fastrtps_cpp/src/rmw_publisher.cpp b/rmw_fastrtps_cpp/src/rmw_publisher.cpp
index 1d101719d..5907590fd 100644
--- a/rmw_fastrtps_cpp/src/rmw_publisher.cpp
+++ b/rmw_fastrtps_cpp/src/rmw_publisher.cpp
@@ -92,7 +92,12 @@ rmw_create_publisher(
   Domain::getDefaultPublisherAttributes(publisherParam);
 
   // TODO(karsten1987) Verify consequences for std::unique_ptr?
-  info = new CustomPublisherInfo();
+  info = new (std::nothrow) CustomPublisherInfo();
+  if (!info) {
+    RMW_SET_ERROR_MSG("failed to allocate CustomPublisherInfo");
+    return nullptr;
+  }
+
   info->typesupport_identifier_ = type_support->typesupport_identifier;
 
   auto callbacks = static_cast<const message_type_support_callbacks_t *>(type_support->data);
@@ -100,7 +105,11 @@ rmw_create_publisher(
   if (!Domain::getRegisteredType(participant, type_name.c_str(),
     reinterpret_cast<TopicDataType **>(&info->type_support_)))
   {
-    info->type_support_ = new MessageTypeSupport_cpp(callbacks);
+    info->type_support_ = new (std::nothrow) MessageTypeSupport_cpp(callbacks);
+    if (!info->type_support_) {
+      RMW_SET_ERROR_MSG("Failed to allocate MessageTypeSupport");
+      goto fail;
+    }
     _register_type(participant, info->type_support_);
   }
 
@@ -128,8 +137,13 @@ rmw_create_publisher(
     goto fail;
   }
 
-  info->publisher_ = Domain::createPublisher(participant, publisherParam, nullptr);
+  info->listener_ = new (std::nothrow) PubListener(info);
+  if (!info->listener_) {
+    RMW_SET_ERROR_MSG("create_publisher() could not create publisher listener");
+    goto fail;
+  }
 
+  info->publisher_ = Domain::createPublisher(participant, publisherParam, info->listener_);
   if (!info->publisher_) {
     RMW_SET_ERROR_MSG("create_publisher() could not create publisher");
     goto fail;
@@ -171,6 +185,9 @@ rmw_create_publisher(
     if (info->type_support_ != nullptr) {
       delete info->type_support_;
     }
+    if (info->listener_ != nullptr) {
+      delete info->listener_;
+    }
     delete info;
   }
 
@@ -181,6 +198,15 @@ rmw_create_publisher(
   return nullptr;
 }
 
+rmw_ret_t
+rmw_publisher_count_matched_subscriptions(
+  const rmw_publisher_t * publisher,
+  size_t * subscription_count)
+{
+  return rmw_fastrtps_shared_cpp::__rmw_publisher_count_matched_subscriptions(
+    publisher, subscription_count);
+}
+
 rmw_ret_t
 rmw_destroy_publisher(rmw_node_t * node, rmw_publisher_t * publisher)
 {
diff --git a/rmw_fastrtps_cpp/src/rmw_subscription.cpp b/rmw_fastrtps_cpp/src/rmw_subscription.cpp
index 887d0ba22..998b859f8 100644
--- a/rmw_fastrtps_cpp/src/rmw_subscription.cpp
+++ b/rmw_fastrtps_cpp/src/rmw_subscription.cpp
@@ -95,7 +95,12 @@ rmw_create_subscription(
   // Load default XML profile.
   Domain::getDefaultSubscriberAttributes(subscriberParam);
 
-  info = new CustomSubscriberInfo();
+  info = new (std::nothrow) CustomSubscriberInfo();
+  if (!info) {
+    RMW_SET_ERROR_MSG("failed to allocate CustomSubscriberInfo");
+    return nullptr;
+  }
+
   info->typesupport_identifier_ = type_support->typesupport_identifier;
 
   auto callbacks = static_cast<const message_type_support_callbacks_t *>(type_support->data);
@@ -103,7 +108,11 @@ rmw_create_subscription(
   if (!Domain::getRegisteredType(participant, type_name.c_str(),
     reinterpret_cast<TopicDataType **>(&info->type_support_)))
   {
-    info->type_support_ = new MessageTypeSupport_cpp(callbacks);
+    info->type_support_ = new (std::nothrow) MessageTypeSupport_cpp(callbacks);
+    if (!info->type_support_) {
+      RMW_SET_ERROR_MSG("failed to allocate MessageTypeSupport_cpp");
+      goto fail;
+    }
     _register_type(participant, info->type_support_);
   }
 
@@ -122,9 +131,13 @@ rmw_create_subscription(
     goto fail;
   }
 
-  info->listener_ = new SubListener(info);
-  info->subscriber_ = Domain::createSubscriber(participant, subscriberParam, info->listener_);
+  info->listener_ = new (std::nothrow) SubListener(info);
+  if (!info->listener_) {
+    RMW_SET_ERROR_MSG("create_subscriber() could not create subscriber listener");
+    goto fail;
+  }
 
+  info->subscriber_ = Domain::createSubscriber(participant, subscriberParam, info->listener_);
   if (!info->subscriber_) {
     RMW_SET_ERROR_MSG("create_subscriber() could not create subscriber");
     goto fail;
@@ -154,6 +167,9 @@ rmw_create_subscription(
     if (info->type_support_ != nullptr) {
       delete info->type_support_;
     }
+    if (info->listener_ != nullptr) {
+      delete info->listener_;
+    }
     delete info;
   }
 
@@ -164,6 +180,15 @@ rmw_create_subscription(
   return nullptr;
 }
 
+rmw_ret_t
+rmw_subscription_count_matched_publishers(
+  const rmw_subscription_t * subscription,
+  size_t * publisher_count)
+{
+  return rmw_fastrtps_shared_cpp::__rmw_subscription_count_matched_publishers(
+    subscription, publisher_count);
+}
+
 rmw_ret_t
 rmw_destroy_subscription(rmw_node_t * node, rmw_subscription_t * subscription)
 {
diff --git a/rmw_fastrtps_dynamic_cpp/src/rmw_publisher.cpp b/rmw_fastrtps_dynamic_cpp/src/rmw_publisher.cpp
index 505d5f710..ae44cfe03 100644
--- a/rmw_fastrtps_dynamic_cpp/src/rmw_publisher.cpp
+++ b/rmw_fastrtps_dynamic_cpp/src/rmw_publisher.cpp
@@ -91,7 +91,11 @@ rmw_create_publisher(
   Domain::getDefaultPublisherAttributes(publisherParam);
 
   // TODO(karsten1987) Verify consequences for std::unique_ptr?
-  info = new CustomPublisherInfo();
+  info = new (std::nothrow) CustomPublisherInfo();
+  if (!info) {
+    RMW_SET_ERROR_MSG("failed to allocate CustomPublisherInfo");
+    return nullptr;
+  }
   info->typesupport_identifier_ = type_support->typesupport_identifier;
 
   std::string type_name = _create_type_name(
@@ -128,8 +132,13 @@ rmw_create_publisher(
     goto fail;
   }
 
-  info->publisher_ = Domain::createPublisher(participant, publisherParam, nullptr);
+  info->listener_ = new (std::nothrow) PubListener(info);
+  if (!info->listener_) {
+    RMW_SET_ERROR_MSG("create_publisher() could not create publisher listener");
+    goto fail;
+  }
 
+  info->publisher_ = Domain::createPublisher(participant, publisherParam, info->listener_);
   if (!info->publisher_) {
     RMW_SET_ERROR_MSG("create_publisher() could not create publisher");
     goto fail;
@@ -171,6 +180,9 @@ rmw_create_publisher(
     if (info->type_support_ != nullptr) {
       delete info->type_support_;
     }
+    if (info->listener_ != nullptr) {
+      delete info->listener_;
+    }
     delete info;
   }
 
@@ -181,6 +193,15 @@ rmw_create_publisher(
   return nullptr;
 }
 
+rmw_ret_t
+rmw_publisher_count_matched_subscriptions(
+  const rmw_publisher_t * publisher,
+  size_t * subscription_count)
+{
+  return rmw_fastrtps_shared_cpp::__rmw_publisher_count_matched_subscriptions(
+    publisher, subscription_count);
+}
+
 rmw_ret_t
 rmw_destroy_publisher(rmw_node_t * node, rmw_publisher_t * publisher)
 {
diff --git a/rmw_fastrtps_dynamic_cpp/src/rmw_serialize.cpp b/rmw_fastrtps_dynamic_cpp/src/rmw_serialize.cpp
index 6af64af4f..64efe0910 100644
--- a/rmw_fastrtps_dynamic_cpp/src/rmw_serialize.cpp
+++ b/rmw_fastrtps_dynamic_cpp/src/rmw_serialize.cpp
@@ -48,7 +48,8 @@ rmw_serialize(
     }
   }
 
-  eprosima::fastcdr::FastBuffer buffer(reinterpret_cast<char *>(serialized_message->buffer),
+  eprosima::fastcdr::FastBuffer buffer(
+    reinterpret_cast<char *>(serialized_message->buffer),
     data_length);
   eprosima::fastcdr::Cdr ser(
     buffer, eprosima::fastcdr::Cdr::DEFAULT_ENDIAN, eprosima::fastcdr::Cdr::DDS_CDR);
diff --git a/rmw_fastrtps_dynamic_cpp/src/rmw_subscription.cpp b/rmw_fastrtps_dynamic_cpp/src/rmw_subscription.cpp
index 6253a4598..a421424fe 100644
--- a/rmw_fastrtps_dynamic_cpp/src/rmw_subscription.cpp
+++ b/rmw_fastrtps_dynamic_cpp/src/rmw_subscription.cpp
@@ -95,7 +95,11 @@ rmw_create_subscription(
   // Load default XML profile.
   Domain::getDefaultSubscriberAttributes(subscriberParam);
 
-  info = new CustomSubscriberInfo();
+  info = new (std::nothrow) CustomSubscriberInfo();
+  if (!info) {
+    RMW_SET_ERROR_MSG("failed to allocate CustomSubscriberInfo");
+    return nullptr;
+  }
   info->typesupport_identifier_ = type_support->typesupport_identifier;
 
   std::string type_name = _create_type_name(
@@ -123,9 +127,13 @@ rmw_create_subscription(
     goto fail;
   }
 
-  info->listener_ = new SubListener(info);
-  info->subscriber_ = Domain::createSubscriber(participant, subscriberParam, info->listener_);
+  info->listener_ = new (std::nothrow) SubListener(info);
+  if (!info->listener_) {
+    RMW_SET_ERROR_MSG("create_subscriber() could not create subscriber listener");
+    goto fail;
+  }
 
+  info->subscriber_ = Domain::createSubscriber(participant, subscriberParam, info->listener_);
   if (!info->subscriber_) {
     RMW_SET_ERROR_MSG("create_subscriber() could not create subscriber");
     goto fail;
@@ -155,6 +163,9 @@ rmw_create_subscription(
     if (info->type_support_ != nullptr) {
       delete info->type_support_;
     }
+    if (info->listener_ != nullptr) {
+      delete info->listener_;
+    }
     delete info;
   }
 
@@ -165,6 +176,15 @@ rmw_create_subscription(
   return nullptr;
 }
 
+rmw_ret_t
+rmw_subscription_count_matched_publishers(
+  const rmw_subscription_t * subscription,
+  size_t * publisher_count)
+{
+  return rmw_fastrtps_shared_cpp::__rmw_subscription_count_matched_publishers(
+    subscription, publisher_count);
+}
+
 rmw_ret_t
 rmw_destroy_subscription(rmw_node_t * node, rmw_subscription_t * subscription)
 {
diff --git a/rmw_fastrtps_shared_cpp/include/rmw_fastrtps_shared_cpp/custom_publisher_info.hpp b/rmw_fastrtps_shared_cpp/include/rmw_fastrtps_shared_cpp/custom_publisher_info.hpp
index 330977b9d..486f10869 100644
--- a/rmw_fastrtps_shared_cpp/include/rmw_fastrtps_shared_cpp/custom_publisher_info.hpp
+++ b/rmw_fastrtps_shared_cpp/include/rmw_fastrtps_shared_cpp/custom_publisher_info.hpp
@@ -15,18 +15,57 @@
 #ifndef RMW_FASTRTPS_SHARED_CPP__CUSTOM_PUBLISHER_INFO_HPP_
 #define RMW_FASTRTPS_SHARED_CPP__CUSTOM_PUBLISHER_INFO_HPP_
 
+#include <mutex>
+#include <set>
+
 #include "fastrtps/publisher/Publisher.h"
+#include "fastrtps/publisher/PublisherListener.h"
 
 #include "rmw/rmw.h"
 
 #include "rmw_fastrtps_shared_cpp/TypeSupport.hpp"
 
+class PubListener;
+
 typedef struct CustomPublisherInfo
 {
   eprosima::fastrtps::Publisher * publisher_;
+  PubListener * listener_;
   rmw_fastrtps_shared_cpp::TypeSupport * type_support_;
   rmw_gid_t publisher_gid;
   const char * typesupport_identifier_;
 } CustomPublisherInfo;
 
+class PubListener : public eprosima::fastrtps::PublisherListener
+{
+public:
+  explicit PubListener(CustomPublisherInfo * info)
+  {
+    (void) info;
+  }
+
+  void
+  onPublicationMatched(
+    eprosima::fastrtps::Publisher * pub, eprosima::fastrtps::rtps::MatchingInfo & info)
+  {
+    (void) pub;
+    std::lock_guard<std::mutex> lock(internalMutex_);
+    if (eprosima::fastrtps::rtps::MATCHED_MATCHING == info.status) {
+      subscriptions_.insert(info.remoteEndpointGuid);
+    } else if (eprosima::fastrtps::rtps::REMOVED_MATCHING == info.status) {
+      subscriptions_.erase(info.remoteEndpointGuid);
+    }
+  }
+
+  size_t subscriptionCount()
+  {
+    std::lock_guard<std::mutex> lock(internalMutex_);
+    return subscriptions_.size();
+  }
+
+private:
+  std::mutex internalMutex_;
+  std::set<eprosima::fastrtps::rtps::GUID_t> subscriptions_;
+};
+
 #endif  // RMW_FASTRTPS_SHARED_CPP__CUSTOM_PUBLISHER_INFO_HPP_
diff --git a/rmw_fastrtps_shared_cpp/include/rmw_fastrtps_shared_cpp/custom_subscriber_info.hpp b/rmw_fastrtps_shared_cpp/include/rmw_fastrtps_shared_cpp/custom_subscriber_info.hpp
index e597d6caf..f3938a146 100644
--- a/rmw_fastrtps_shared_cpp/include/rmw_fastrtps_shared_cpp/custom_subscriber_info.hpp
+++ b/rmw_fastrtps_shared_cpp/include/rmw_fastrtps_shared_cpp/custom_subscriber_info.hpp
@@ -18,6 +18,7 @@
 #include <atomic>
 #include <condition_variable>
 #include <mutex>
+#include <set>
 #include <utility>
 
 #include "fastrtps/subscriber/Subscriber.h"
@@ -51,7 +52,13 @@ class SubListener : public eprosima::fastrtps::SubscriberListener
     eprosima::fastrtps::Subscriber * sub, eprosima::fastrtps::rtps::MatchingInfo & info)
   {
     (void)sub;
-    (void)info;
+
+    std::lock_guard<std::mutex> lock(internalMutex_);
+    if (eprosima::fastrtps::rtps::MATCHED_MATCHING == info.status) {
+      publishers_.insert(info.remoteEndpointGuid);
+    } else if (eprosima::fastrtps::rtps::REMOVED_MATCHING == info.status) {
+      publishers_.erase(info.remoteEndpointGuid);
+    }
   }
 
   void
@@ -107,11 +114,19 @@ class SubListener : public eprosima::fastrtps::SubscriberListener
     }
   }
 
+  size_t publisherCount()
+  {
+    std::lock_guard<std::mutex> lock(internalMutex_);
+    return publishers_.size();
+  }
+
 private:
   std::mutex internalMutex_;
   std::atomic_size_t data_;
   std::mutex * conditionMutex_;
   std::condition_variable * conditionVariable_;
+
+  std::set<eprosima::fastrtps::rtps::GUID_t> publishers_;
 };
 
 #endif  // RMW_FASTRTPS_SHARED_CPP__CUSTOM_SUBSCRIBER_INFO_HPP_
diff --git a/rmw_fastrtps_shared_cpp/include/rmw_fastrtps_shared_cpp/rmw_common.hpp b/rmw_fastrtps_shared_cpp/include/rmw_fastrtps_shared_cpp/rmw_common.hpp
index 44c06a77e..a4d968cb3 100644
--- a/rmw_fastrtps_shared_cpp/include/rmw_fastrtps_shared_cpp/rmw_common.hpp
+++ b/rmw_fastrtps_shared_cpp/include/rmw_fastrtps_shared_cpp/rmw_common.hpp
@@ -129,6 +129,12 @@ __rmw_destroy_publisher(
   rmw_node_t * node,
   rmw_publisher_t * publisher);
 
+RMW_FASTRTPS_SHARED_CPP_PUBLIC
+rmw_ret_t
+__rmw_publisher_count_matched_subscriptions(
+  const rmw_publisher_t * publisher,
+  size_t * subscription_count);
+
 RMW_FASTRTPS_SHARED_CPP_PUBLIC
 rmw_ret_t
 __rmw_send_request(
@@ -193,6 +199,12 @@ __rmw_destroy_subscription(
   rmw_node_t * node,
   rmw_subscription_t * subscription);
 
+RMW_FASTRTPS_SHARED_CPP_PUBLIC
+rmw_ret_t
+__rmw_subscription_count_matched_publishers(
+  const rmw_subscription_t * subscription,
+  size_t * publisher_count);
+
 RMW_FASTRTPS_SHARED_CPP_PUBLIC
 rmw_ret_t
 __rmw_take(
diff --git a/rmw_fastrtps_shared_cpp/src/rmw_publisher.cpp b/rmw_fastrtps_shared_cpp/src/rmw_publisher.cpp
index 8458e6033..f31301e4d 100644
--- a/rmw_fastrtps_shared_cpp/src/rmw_publisher.cpp
+++ b/rmw_fastrtps_shared_cpp/src/rmw_publisher.cpp
@@ -64,6 +64,9 @@ __rmw_destroy_publisher(
     if (info->publisher_ != nullptr) {
       Domain::removePublisher(info->publisher_);
     }
+    if (info->listener_ != nullptr) {
+      delete info->listener_;
+    }
     if (info->type_support_ != nullptr) {
       auto impl = static_cast<CustomParticipantInfo *>(node->data);
       if (!impl) {
@@ -82,4 +85,20 @@ __rmw_destroy_publisher(
 
   return RMW_RET_OK;
 }
+
+rmw_ret_t
+__rmw_publisher_count_matched_subscriptions(
+  const rmw_publisher_t * publisher,
+  size_t * subscription_count)
+{
+  RMW_CHECK_ARGUMENT_FOR_NULL(publisher, RMW_RET_INVALID_ARGUMENT);
+  RMW_CHECK_ARGUMENT_FOR_NULL(subscription_count, RMW_RET_INVALID_ARGUMENT);
+
+  auto info = static_cast<CustomPublisherInfo *>(publisher->data);
+  if (info != nullptr) {
+    *subscription_count = info->listener_->subscriptionCount();
+  }
+
+  return RMW_RET_OK;
+}
 }  // namespace rmw_fastrtps_shared_cpp
diff --git a/rmw_fastrtps_shared_cpp/src/rmw_subscription.cpp b/rmw_fastrtps_shared_cpp/src/rmw_subscription.cpp
index 1a52e8dec..c237aa5cf 100644
--- a/rmw_fastrtps_shared_cpp/src/rmw_subscription.cpp
+++ b/rmw_fastrtps_shared_cpp/src/rmw_subscription.cpp
@@ -91,4 +91,20 @@ __rmw_destroy_subscription(
 
   return RMW_RET_OK;
 }
+
+rmw_ret_t
+__rmw_subscription_count_matched_publishers(
+  const rmw_subscription_t * subscription,
+  size_t * publisher_count)
+{
+  RMW_CHECK_ARGUMENT_FOR_NULL(subscription, RMW_RET_INVALID_ARGUMENT);
+  RMW_CHECK_ARGUMENT_FOR_NULL(publisher_count, RMW_RET_INVALID_ARGUMENT);
+
+  auto info = static_cast<CustomSubscriberInfo *>(subscription->data);
+  if (info != nullptr) {
+    *publisher_count = info->listener_->publisherCount();
+  }
+  return RMW_RET_OK;
+}
+
 }  // namespace rmw_fastrtps_shared_cpp