Seperate InitDataModel out

src/app/codegen-data-model-provider/CodegenDataModelProvider.cpp

@@ -412,6 +412,13 @@ DefaultAttributePersistenceProvider gDefaultAttributePersistence;
 
 } // namespace
 
+void CodegenDataModelProvider::InitDataModel()
+{
+    // Call the Ember-specific InitDataModelHandler
+    InitDataModelHandler();
+    ChipLogProgress(AppServer, "CodegenDataModelHandler initialized.");
+}
+
 CHIP_ERROR CodegenDataModelProvider::Startup(DataModel::InteractionModelContext context)
 {
     ReturnErrorOnFailure(DataModel::Provider::Startup(context));
@@ -438,9 +445,6 @@ CHIP_ERROR CodegenDataModelProvider::Startup(DataModel::InteractionModelContext
         }
     }
 
-    // Call the Ember-specific InitDataModelHandler
-    InitDataModelHandler();
-
     return CHIP_NO_ERROR;
 }
 

src/app/codegen-data-model-provider/CodegenDataModelProvider.h

@@ -126,6 +126,9 @@ class CodegenDataModelProvider : public DataModel::Provider
     };
 
 public:
+    /// Initialize the data model internal code to be ready to send and receive data model messages.
+    void InitDataModel() override;
+
     /// clears out internal caching. Especially useful in unit tests,
     /// where path caching does not really apply (the same path may result in different outcomes)
     void Reset()

src/app/data-model-provider/Provider.h

@@ -47,6 +47,9 @@ class Provider : public ProviderMetadataTree
 public:
     virtual ~Provider() = default;
 
+    // Initialize the data model internal code to be ready to send and receive data model messages.
+    virtual void InitDataModel() {}
+
     // `context` pointers  will be guaranteed valid until Shutdown is called()
     virtual CHIP_ERROR Startup(InteractionModelContext context)
     {

src/app/server/Server.cpp

@@ -169,6 +169,17 @@ CHIP_ERROR Server::Init(const ServerInitParams & initParams)
     SuccessOrExit(err = mAttributePersister.Init(mDeviceStorage));
     SetSafeAttributePersistenceProvider(&mAttributePersister);
 
+    // SetDataModelProvider() actually initializes/starts the provider.  We need
+    // to preserve the following ordering guarantees:
+    //
+    // 1) Provider initialization (under SetDataModelProvider) happens after
+    //    SetSafeAttributePersistenceProvider, since the provider can then use
+    //    the safe persistence provider to implement and initialize its own attribute persistence logic.
+    // 2) For now, provider initialization happens before InitDataModelHandler(), which depends
+    //    on atttribute persistence being already set up before it runs.  Longer-term, the logic from
+    //    InitDataModelHandler should just move into the codegen provider.
+    app::InteractionModelEngine::GetInstance()->SetDataModelProvider(initParams.dataModelProvider);
+
     {
         FabricTable::InitParams fabricTableInitParams;
         fabricTableInitParams.storage             = mDeviceStorage;
@@ -290,10 +301,8 @@ CHIP_ERROR Server::Init(const ServerInitParams & initParams)
     }
 #endif // CHIP_CONFIG_ENABLE_SERVER_IM_EVENT
 
-    // Set the data model provider, initializing it in the process. This must
-    // happen after SetSafeAttributePersistenceProvider to ensure the provider
-    // can utilize the safe persistence provider for its attribute storage.
-    app::InteractionModelEngine::GetInstance()->SetDataModelProvider(initParams.dataModelProvider);
+    // This initializes clusters, so should come after lower level initialization.
+    app::InteractionModelEngine::GetInstance()->GetDataModelProvider()->InitDataModel();
 
 #if defined(CHIP_APP_USE_ECHO)
     err = InitEchoHandler(&mExchangeMgr);

src/app/tests/test-interaction-model-api.h

@@ -101,6 +101,8 @@ class TestImCustomDataModel : public DataModel::Provider
 public:
     static TestImCustomDataModel & Instance();
 
+    void InitDataModel() override {}
+
     CHIP_ERROR Shutdown() override { return CHIP_NO_ERROR; }
 
     DataModel::ActionReturnStatus ReadAttribute(const DataModel::ReadAttributeRequest & request,