Refs #21664. Use atomic enumeration to control the instance state.

Signed-off-by: Miguel Company <[email protected]>

src/cpp/dynamic-types/TypeObjectFactory.cpp

@@ -25,6 +25,7 @@
 #include <fastrtps/types/AnnotationDescriptor.h>
 #include <fastrtps/utils/md5.h>
 #include <fastdds/dds/log/Log.hpp>
+#include <atomic>
 #include <sstream>
 
 namespace eprosima {
@@ -42,26 +43,51 @@ class TypeObjectFactoryReleaser
 
 };
 
+enum class TypeObjectFactoryInstanceState
+{
+    NOT_CREATED = 0,  // Instance has not been created
+    CREATING = 1,     // Instance is being created
+    CREATED = 2,      // Instance has been created
+    DESTROYING = 3    // Instance is being destroyed
+};
+
+static std::atomic<TypeObjectFactoryInstanceState> g_instance_state{TypeObjectFactoryInstanceState::NOT_CREATED};
 static TypeObjectFactoryReleaser s_releaser;
 static TypeObjectFactory* g_instance = nullptr;
+
 TypeObjectFactory* TypeObjectFactory::get_instance()
 {
-    if (g_instance == nullptr)
+    TypeObjectFactoryInstanceState expected_state = TypeObjectFactoryInstanceState::NOT_CREATED;
+
+    // Wait until the instance is either created or destroyed
+    while (!g_instance_state.compare_exchange_weak(expected_state, TypeObjectFactoryInstanceState::CREATING))
     {
-        auto instance = new TypeObjectFactory();
-        g_instance = instance;
-        g_instance->create_builtin_annotations();
-        return instance;
+        // If it is already created, return it
+        if (expected_state == TypeObjectFactoryInstanceState::CREATED)
+        {
+            return g_instance;
+        }
+
+        // Prepare for retry
+        expected_state = TypeObjectFactoryInstanceState::NOT_CREATED;
     }
-    return g_instance;
+
+    auto instance = new TypeObjectFactory();
+    instance->create_builtin_annotations();
+    g_instance = instance;
+    g_instance_state.store(TypeObjectFactoryInstanceState::CREATED);
+
+    return instance;
 }
 
 ReturnCode_t TypeObjectFactory::delete_instance()
 {
-    if (g_instance != nullptr)
+    TypeObjectFactoryInstanceState expected_state = TypeObjectFactoryInstanceState::CREATED;
+    if (g_instance_state.compare_exchange_strong(expected_state, TypeObjectFactoryInstanceState::DESTROYING))
     {
         delete g_instance;
         g_instance = nullptr;
+        g_instance_state.store(TypeObjectFactoryInstanceState::NOT_CREATED);
         return ReturnCode_t::RETCODE_OK;
     }
     return ReturnCode_t::RETCODE_ERROR;