diff --git a/rmw_fastrtps_cpp/include/rmw_fastrtps_cpp/custom_client_info.hpp b/rmw_fastrtps_cpp/include/rmw_fastrtps_cpp/custom_client_info.hpp
index dbb4f3d20..b085a80db 100644
--- a/rmw_fastrtps_cpp/include/rmw_fastrtps_cpp/custom_client_info.hpp
+++ b/rmw_fastrtps_cpp/include/rmw_fastrtps_cpp/custom_client_info.hpp
@@ -16,11 +16,6 @@
 #define RMW_FASTRTPS_CPP__CUSTOM_CLIENT_INFO_HPP_
 
 #include <atomic>
-#include <list>
-#include <memory>
-#include <utility>
-
-#include "fastcdr/FastBuffer.h"
 
 #include "fastrtps/subscriber/SampleInfo.h"
 #include "fastrtps/subscriber/Subscriber.h"
@@ -28,6 +23,8 @@
 #include "fastrtps/participant/Participant.h"
 #include "fastrtps/publisher/Publisher.h"
 
+using SampleIdentity = eprosima::fastrtps::rtps::SampleIdentity;
+
 class ClientListener;
 
 typedef struct CustomClientInfo
@@ -42,12 +39,6 @@ typedef struct CustomClientInfo
   const char * typesupport_identifier_;
 } CustomClientInfo;
 
-typedef struct CustomClientResponse
-{
-  eprosima::fastrtps::rtps::SampleIdentity sample_identity_;
-  std::unique_ptr<eprosima::fastcdr::FastBuffer> buffer_;
-} CustomClientResponse;
-
 class ClientListener : public eprosima::fastrtps::SubscriberListener
 {
 public:
@@ -59,59 +50,47 @@ class ClientListener : public eprosima::fastrtps::SubscriberListener
   void
   onNewDataMessage(eprosima::fastrtps::Subscriber * sub)
   {
-    assert(sub);
-
-    CustomClientResponse response;
-    // Todo(sloretz) eliminate heap allocation pending eprosima/Fast-CDR#19
-    response.buffer_.reset(new eprosima::fastcdr::FastBuffer());
-    eprosima::fastrtps::SampleInfo_t sinfo;
-
-    if (sub->takeNextData(response.buffer_.get(), &sinfo)) {
-      if (eprosima::fastrtps::rtps::ALIVE == sinfo.sampleKind) {
-        response.sample_identity_ = sinfo.related_sample_identity;
-
-        if (response.sample_identity_.writer_guid() == info_->writer_guid_) {
-          std::lock_guard<std::mutex> lock(internalMutex_);
-
-          if (conditionMutex_ != nullptr) {
-            std::unique_lock<std::mutex> clock(*conditionMutex_);
-            list.emplace_back(std::move(response));
-            // the change to list_has_data_ needs to be mutually exclusive with
-            // rmw_wait() which checks hasData() and decides if wait() needs to
-            // be called
-            list_has_data_.store(true);
-            clock.unlock();
-            conditionVariable_->notify_one();
-          } else {
-            list.emplace_back(std::move(response));
-            list_has_data_.store(true);
-          }
-        }
-      }
+    (void) sub;
+    std::lock_guard<std::mutex> lock(internalMutex_);
+
+    if (conditionMutex_ != nullptr) {
+      std::unique_lock<std::mutex> clock(*conditionMutex_);
+      // the change to list_has_data_ needs to be mutually exclusive with
+      // rmw_wait() which checks hasData() and decides if wait() needs to
+      // be called
+      list_has_data_.store(true);
+      clock.unlock();
+      conditionVariable_->notify_one();
+    } else {
+      list_has_data_.store(true);
     }
   }
 
   bool
-  getResponse(CustomClientResponse & response)
+  getResponse(void * data, SampleIdentity & identity)
   {
     std::lock_guard<std::mutex> lock(internalMutex_);
 
-    auto pop_response = [this](CustomClientResponse & response) -> bool
+    auto pop_response = [this](void * data, SampleIdentity & identity) -> bool
       {
-        if (!list.empty()) {
-          response = std::move(list.front());
-          list.pop_front();
-          list_has_data_.store(!list.empty());
-          return true;
+        eprosima::fastrtps::SampleInfo_t sinfo;
+        bool ret_val = false;
+        auto subs = info_->response_subscriber_;
+        while (!ret_val && (subs->getUnreadCount() > 0) && (subs->takeNextData(data, &sinfo))) {
+          if (eprosima::fastrtps::rtps::ALIVE == sinfo.sampleKind) {
+            identity = sinfo.related_sample_identity;
+            ret_val = (identity.writer_guid() == info_->writer_guid_);
+          }
         }
-        return false;
+        list_has_data_.store(subs->getUnreadCount() > 0);
+        return ret_val;
       };
 
     if (conditionMutex_ != nullptr) {
       std::unique_lock<std::mutex> clock(*conditionMutex_);
-      return pop_response(response);
+      return pop_response(data, identity);
     }
-    return pop_response(response);
+    return pop_response(data, identity);
   }
 
   void
@@ -139,7 +118,6 @@ class ClientListener : public eprosima::fastrtps::SubscriberListener
 private:
   CustomClientInfo * info_;
   std::mutex internalMutex_;
-  std::list<CustomClientResponse> list;
   std::atomic_bool list_has_data_;
   std::mutex * conditionMutex_;
   std::condition_variable * conditionVariable_;
diff --git a/rmw_fastrtps_cpp/include/rmw_fastrtps_cpp/custom_service_info.hpp b/rmw_fastrtps_cpp/include/rmw_fastrtps_cpp/custom_service_info.hpp
index 0ca083c46..6fdb4bdd7 100644
--- a/rmw_fastrtps_cpp/include/rmw_fastrtps_cpp/custom_service_info.hpp
+++ b/rmw_fastrtps_cpp/include/rmw_fastrtps_cpp/custom_service_info.hpp
@@ -16,9 +16,6 @@
 #define RMW_FASTRTPS_CPP__CUSTOM_SERVICE_INFO_HPP_
 
 #include <atomic>
-#include <list>
-
-#include "fastcdr/FastBuffer.h"
 
 #include "fastrtps/participant/Participant.h"
 #include "fastrtps/publisher/Publisher.h"
@@ -27,6 +24,8 @@
 #include "fastrtps/subscriber/SubscriberListener.h"
 #include "fastrtps/subscriber/SampleInfo.h"
 
+using SampleIdentity = eprosima::fastrtps::rtps::SampleIdentity;
+
 class ServiceListener;
 
 typedef struct CustomServiceInfo
@@ -40,15 +39,6 @@ typedef struct CustomServiceInfo
   const char * typesupport_identifier_;
 } CustomServiceInfo;
 
-typedef struct CustomServiceRequest
-{
-  eprosima::fastrtps::rtps::SampleIdentity sample_identity_;
-  eprosima::fastcdr::FastBuffer * buffer_;
-
-  CustomServiceRequest()
-  : buffer_(nullptr) {}
-} CustomServiceRequest;
-
 class ServiceListener : public eprosima::fastrtps::SubscriberListener
 {
 public:
@@ -63,57 +53,45 @@ class ServiceListener : public eprosima::fastrtps::SubscriberListener
   void
   onNewDataMessage(eprosima::fastrtps::Subscriber * sub)
   {
-    assert(sub);
-
-    CustomServiceRequest request;
-    request.buffer_ = new eprosima::fastcdr::FastBuffer();
-    eprosima::fastrtps::SampleInfo_t sinfo;
-
-    if (sub->takeNextData(request.buffer_, &sinfo)) {
-      if (eprosima::fastrtps::rtps::ALIVE == sinfo.sampleKind) {
-        request.sample_identity_ = sinfo.sample_identity;
-
-        std::lock_guard<std::mutex> lock(internalMutex_);
-
-        if (conditionMutex_ != nullptr) {
-          std::unique_lock<std::mutex> clock(*conditionMutex_);
-          list.push_back(request);
-          // the change to list_has_data_ needs to be mutually exclusive with
-          // rmw_wait() which checks hasData() and decides if wait() needs to
-          // be called
-          list_has_data_.store(true);
-          clock.unlock();
-          conditionVariable_->notify_one();
-        } else {
-          list.push_back(request);
-          list_has_data_.store(true);
-        }
-      }
+    (void) sub;
+    std::lock_guard<std::mutex> lock(internalMutex_);
+
+    if (conditionMutex_ != nullptr) {
+      std::unique_lock<std::mutex> clock(*conditionMutex_);
+      // the change to list_has_data_ needs to be mutually exclusive with
+      // rmw_wait() which checks hasData() and decides if wait() needs to
+      // be called
+      list_has_data_.store(true);
+      clock.unlock();
+      conditionVariable_->notify_one();
+    } else {
+      list_has_data_.store(true);
     }
   }
 
-  CustomServiceRequest
-  getRequest()
+  bool
+  getRequest(void * data, SampleIdentity & identity)
   {
     std::lock_guard<std::mutex> lock(internalMutex_);
-    CustomServiceRequest request;
+
+    auto pop_request = [this](void * data, SampleIdentity & identity) -> bool
+      {
+        eprosima::fastrtps::SampleInfo_t sinfo;
+        bool ret_val = false;
+        auto subs = info_->request_subscriber_;
+        while (!ret_val && (subs->getUnreadCount() > 0) && (subs->takeNextData(data, &sinfo))) {
+          identity = sinfo.sample_identity;
+          ret_val = (eprosima::fastrtps::rtps::ALIVE == sinfo.sampleKind);
+        }
+        list_has_data_.store(subs->getUnreadCount() > 0);
+        return ret_val;
+      };
 
     if (conditionMutex_ != nullptr) {
       std::unique_lock<std::mutex> clock(*conditionMutex_);
-      if (!list.empty()) {
-        request = list.front();
-        list.pop_front();
-        list_has_data_.store(!list.empty());
-      }
-    } else {
-      if (!list.empty()) {
-        request = list.front();
-        list.pop_front();
-        list_has_data_.store(!list.empty());
-      }
+      return pop_request(data, identity);
     }
-
-    return request;
+    return pop_request(data, identity);
   }
 
   void
@@ -141,7 +119,6 @@ class ServiceListener : public eprosima::fastrtps::SubscriberListener
 private:
   CustomServiceInfo * info_;
   std::mutex internalMutex_;
-  std::list<CustomServiceRequest> list;
   std::atomic_bool list_has_data_;
   std::mutex * conditionMutex_;
   std::condition_variable * conditionVariable_;
diff --git a/rmw_fastrtps_cpp/src/rmw_request.cpp b/rmw_fastrtps_cpp/src/rmw_request.cpp
index c0a0c1282..263d47e39 100644
--- a/rmw_fastrtps_cpp/src/rmw_request.cpp
+++ b/rmw_fastrtps_cpp/src/rmw_request.cpp
@@ -95,21 +95,19 @@ rmw_take_request(
   auto info = static_cast<CustomServiceInfo *>(service->data);
   assert(info);
 
-  CustomServiceRequest request = info->listener_->getRequest();
-  eprosima::fastcdr::Cdr deser(*request.buffer_, eprosima::fastcdr::Cdr::DEFAULT_ENDIAN,
-    eprosima::fastcdr::Cdr::DDS_CDR);
-
-  if (request.buffer_ != nullptr) {
+  eprosima::fastcdr::FastBuffer buffer;
+  eprosima::fastrtps::rtps::SampleIdentity sample_identity;
+  if (info->listener_->getRequest(&buffer, sample_identity)) {
+    eprosima::fastcdr::Cdr deser(buffer, eprosima::fastcdr::Cdr::DEFAULT_ENDIAN,
+      eprosima::fastcdr::Cdr::DDS_CDR);
     _deserialize_ros_message(deser, ros_request, info->request_type_support_,
       info->typesupport_identifier_);
 
     // Get header
-    memcpy(request_header->writer_guid, &request.sample_identity_.writer_guid(),
+    memcpy(request_header->writer_guid, &sample_identity.writer_guid(),
       sizeof(eprosima::fastrtps::rtps::GUID_t));
-    request_header->sequence_number = ((int64_t)request.sample_identity_.sequence_number().high) <<
-      32 | request.sample_identity_.sequence_number().low;
-
-    delete request.buffer_;
+    request_header->sequence_number = ((int64_t)sample_identity.sequence_number().high) <<
+      32 | sample_identity.sequence_number().low;
 
     *taken = true;
   }
diff --git a/rmw_fastrtps_cpp/src/rmw_response.cpp b/rmw_fastrtps_cpp/src/rmw_response.cpp
index d8142f818..7c8e7f4ce 100644
--- a/rmw_fastrtps_cpp/src/rmw_response.cpp
+++ b/rmw_fastrtps_cpp/src/rmw_response.cpp
@@ -15,6 +15,7 @@
 #include <cassert>
 
 #include "fastcdr/Cdr.h"
+#include "fastcdr/FastBuffer.h"
 
 #include "fastrtps/subscriber/Subscriber.h"
 
@@ -50,18 +51,19 @@ rmw_take_response(
   auto info = static_cast<CustomClientInfo *>(client->data);
   assert(info);
 
-  CustomClientResponse response;
+  eprosima::fastcdr::FastBuffer buffer;
+  eprosima::fastrtps::rtps::SampleIdentity sample_identity;
 
-  if (info->listener_->getResponse(response)) {
+  if (info->listener_->getResponse(&buffer, sample_identity)) {
     eprosima::fastcdr::Cdr deser(
-      *response.buffer_,
+      buffer,
       eprosima::fastcdr::Cdr::DEFAULT_ENDIAN,
       eprosima::fastcdr::Cdr::DDS_CDR);
     _deserialize_ros_message(
       deser, ros_response, info->response_type_support_, info->typesupport_identifier_);
 
-    request_header->sequence_number = ((int64_t)response.sample_identity_.sequence_number().high) <<
-      32 | response.sample_identity_.sequence_number().low;
+    request_header->sequence_number = ((int64_t)sample_identity.sequence_number().high) <<
+      32 | sample_identity.sequence_number().low;
 
     *taken = true;
   }