From 92586f4538db5d34e7aba77581aa0e19bce8cc36 Mon Sep 17 00:00:00 2001
From: Miguel Company <MiguelCompany@eprosima.com>
Date: Thu, 22 Jul 2021 15:17:34 +0200
Subject: [PATCH 1/2] Prepare type size for alignment requirements.

Signed-off-by: Miguel Company <MiguelCompany@eprosima.com>
---
 rmw_fastrtps_cpp/src/type_support_common.cpp                    | 1 +
 .../rmw_fastrtps_dynamic_cpp/MessageTypeSupport_impl.hpp        | 1 +
 .../rmw_fastrtps_dynamic_cpp/ServiceTypeSupport_impl.hpp        | 2 ++
 3 files changed, 4 insertions(+)

diff --git a/rmw_fastrtps_cpp/src/type_support_common.cpp b/rmw_fastrtps_cpp/src/type_support_common.cpp
index ef5567641..bbca127eb 100644
--- a/rmw_fastrtps_cpp/src/type_support_common.cpp
+++ b/rmw_fastrtps_cpp/src/type_support_common.cpp
@@ -54,6 +54,7 @@ void TypeSupport::set_members(const message_type_support_callbacks_t * members)
 
   // Total size is encapsulation size + data size
   m_typeSize = 4 + data_size;
+  m_typeSize = (m_typeSize + 3) & ~3;
 }
 
 size_t TypeSupport::getEstimatedSerializedSize(const void * ros_message, const void * impl) const
diff --git a/rmw_fastrtps_dynamic_cpp/include/rmw_fastrtps_dynamic_cpp/MessageTypeSupport_impl.hpp b/rmw_fastrtps_dynamic_cpp/include/rmw_fastrtps_dynamic_cpp/MessageTypeSupport_impl.hpp
index a21e20721..bc88f12e1 100644
--- a/rmw_fastrtps_dynamic_cpp/include/rmw_fastrtps_dynamic_cpp/MessageTypeSupport_impl.hpp
+++ b/rmw_fastrtps_dynamic_cpp/include/rmw_fastrtps_dynamic_cpp/MessageTypeSupport_impl.hpp
@@ -60,6 +60,7 @@ MessageTypeSupport<MembersType>::MessageTypeSupport(
   } else {
     this->m_typeSize++;
   }
+  this->m_typeSize = (this->m_typeSize + 3) & ~3;
 }
 
 }  // namespace rmw_fastrtps_dynamic_cpp
diff --git a/rmw_fastrtps_dynamic_cpp/include/rmw_fastrtps_dynamic_cpp/ServiceTypeSupport_impl.hpp b/rmw_fastrtps_dynamic_cpp/include/rmw_fastrtps_dynamic_cpp/ServiceTypeSupport_impl.hpp
index 467703712..a3bf402c1 100644
--- a/rmw_fastrtps_dynamic_cpp/include/rmw_fastrtps_dynamic_cpp/ServiceTypeSupport_impl.hpp
+++ b/rmw_fastrtps_dynamic_cpp/include/rmw_fastrtps_dynamic_cpp/ServiceTypeSupport_impl.hpp
@@ -59,6 +59,7 @@ RequestTypeSupport<ServiceMembersType, MessageMembersType>::RequestTypeSupport(
   } else {
     this->m_typeSize++;
   }
+  this->m_typeSize = (this->m_typeSize + 3) & ~3;
 }
 
 template<typename ServiceMembersType, typename MessageMembersType>
@@ -90,6 +91,7 @@ ResponseTypeSupport<ServiceMembersType, MessageMembersType>::ResponseTypeSupport
   } else {
     this->m_typeSize++;
   }
+  this->m_typeSize = (this->m_typeSize + 3) & ~3;
 }
 
 }  // namespace rmw_fastrtps_dynamic_cpp

From 4584b75095a1c0a560b59713b093a32d6325ef7b Mon Sep 17 00:00:00 2001
From: Miguel Company <MiguelCompany@eprosima.com>
Date: Mon, 26 Jul 2021 08:44:51 +0200
Subject: [PATCH 2/2] Add comments on alignment code.

Signed-off-by: Miguel Company <MiguelCompany@eprosima.com>
---
 rmw_fastrtps_cpp/src/type_support_common.cpp                    | 1 +
 .../rmw_fastrtps_dynamic_cpp/MessageTypeSupport_impl.hpp        | 1 +
 .../rmw_fastrtps_dynamic_cpp/ServiceTypeSupport_impl.hpp        | 2 ++
 3 files changed, 4 insertions(+)

diff --git a/rmw_fastrtps_cpp/src/type_support_common.cpp b/rmw_fastrtps_cpp/src/type_support_common.cpp
index bbca127eb..25bdb86a4 100644
--- a/rmw_fastrtps_cpp/src/type_support_common.cpp
+++ b/rmw_fastrtps_cpp/src/type_support_common.cpp
@@ -54,6 +54,7 @@ void TypeSupport::set_members(const message_type_support_callbacks_t * members)
 
   // Total size is encapsulation size + data size
   m_typeSize = 4 + data_size;
+  // Account for RTPS submessage alignment
   m_typeSize = (m_typeSize + 3) & ~3;
 }
 
diff --git a/rmw_fastrtps_dynamic_cpp/include/rmw_fastrtps_dynamic_cpp/MessageTypeSupport_impl.hpp b/rmw_fastrtps_dynamic_cpp/include/rmw_fastrtps_dynamic_cpp/MessageTypeSupport_impl.hpp
index bc88f12e1..95f48e996 100644
--- a/rmw_fastrtps_dynamic_cpp/include/rmw_fastrtps_dynamic_cpp/MessageTypeSupport_impl.hpp
+++ b/rmw_fastrtps_dynamic_cpp/include/rmw_fastrtps_dynamic_cpp/MessageTypeSupport_impl.hpp
@@ -60,6 +60,7 @@ MessageTypeSupport<MembersType>::MessageTypeSupport(
   } else {
     this->m_typeSize++;
   }
+  // Account for RTPS submessage alignment
   this->m_typeSize = (this->m_typeSize + 3) & ~3;
 }
 
diff --git a/rmw_fastrtps_dynamic_cpp/include/rmw_fastrtps_dynamic_cpp/ServiceTypeSupport_impl.hpp b/rmw_fastrtps_dynamic_cpp/include/rmw_fastrtps_dynamic_cpp/ServiceTypeSupport_impl.hpp
index a3bf402c1..45e3fc602 100644
--- a/rmw_fastrtps_dynamic_cpp/include/rmw_fastrtps_dynamic_cpp/ServiceTypeSupport_impl.hpp
+++ b/rmw_fastrtps_dynamic_cpp/include/rmw_fastrtps_dynamic_cpp/ServiceTypeSupport_impl.hpp
@@ -59,6 +59,7 @@ RequestTypeSupport<ServiceMembersType, MessageMembersType>::RequestTypeSupport(
   } else {
     this->m_typeSize++;
   }
+  // Account for RTPS submessage alignment
   this->m_typeSize = (this->m_typeSize + 3) & ~3;
 }
 
@@ -91,6 +92,7 @@ ResponseTypeSupport<ServiceMembersType, MessageMembersType>::ResponseTypeSupport
   } else {
     this->m_typeSize++;
   }
+  // Account for RTPS submessage alignment
   this->m_typeSize = (this->m_typeSize + 3) & ~3;
 }