read/write same thread local storage

src/realm/exceptions.hpp

@@ -113,6 +113,15 @@ struct RuntimeError : Exception {
     ~RuntimeError() noexcept override;
 };
 
+struct UserCodeCallbackError : RuntimeError {
+    void* user_code_error = nullptr;
+    UserCodeCallbackError(ErrorCodes::Error code, std::string_view msg)
+        : RuntimeError(code, msg)
+    {
+    }
+    ~UserCodeCallbackError() noexcept override = default;
+};
+
 /// Thrown when creating references that are too large to be contained in our ref_type (size_t)
 struct MaximumFileSizeExceeded : RuntimeError {
     MaximumFileSizeExceeded(std::string_view msg)

src/realm/object-store/c_api/sync.cpp

@@ -264,7 +264,8 @@ RLM_API void realm_sync_config_set_error_handler(realm_sync_config_t* config, re
         c_error.server_requests_action = static_cast<realm_sync_error_action_e>(error.server_requests_action);
         c_error.c_original_file_path_key = error.c_original_file_path_key;
         c_error.c_recovery_file_path_key = error.c_recovery_file_path_key;
-        c_error.user_code_error = ErrorStorage::get_thread_local()->get_and_clear_user_code_error();
+        c_error.user_code_error = error.user_code_error;
+        // ErrorStorage::get_thread_local()->get_and_clear_user_code_error();
 
         std::vector<realm_sync_error_user_info_t> c_user_info;
         c_user_info.reserve(error.user_info.size());
@@ -389,7 +390,7 @@ RLM_API void realm_sync_config_set_before_client_reset_handler(realm_sync_config
     auto cb = [callback, userdata = SharedUserdata(userdata, FreeUserdata(userdata_free))](SharedRealm before_realm) {
         realm_t r1{before_realm};
         if (!callback(userdata.get(), &r1)) {
-            throw CallbackFailed{};
+            throw CallbackFailed{ErrorStorage::get_thread_local()->get_and_clear_user_code_error()};
         }
     };
     config->notify_before_client_reset = std::move(cb);
@@ -405,7 +406,7 @@ RLM_API void realm_sync_config_set_after_client_reset_handler(realm_sync_config_
         realm_t r1{before_realm};
         auto tsr = realm_t::thread_safe_reference(std::move(after_realm));
         if (!callback(userdata.get(), &r1, &tsr, did_recover)) {
-            throw CallbackFailed{};
+            throw CallbackFailed{ErrorStorage::get_thread_local()->get_and_clear_user_code_error()};
         }
     };
     config->notify_after_client_reset = std::move(cb);

src/realm/object-store/c_api/types.hpp

@@ -37,14 +37,13 @@ class NotClonable : public RuntimeError {
     }
 };
 
-class CallbackFailed : public RuntimeError {
+class CallbackFailed : public UserCodeCallbackError {
 public:
     // SDK-provided opaque error value when error == RLM_ERR_CALLBACK with a callout to
     // realm_register_user_code_callback_error()
-    void* user_code_error{nullptr};
 
     CallbackFailed()
-        : RuntimeError(ErrorCodes::CallbackFailed, "User-provided callback failed")
+        : UserCodeCallbackError(ErrorCodes::CallbackFailed, "User-provided callback failed")
     {
     }
 

src/realm/object-store/sync/sync_session.cpp

@@ -735,6 +735,7 @@ void SyncSession::handle_error(sync::SessionErrorInfo error)
     // `action` is used over `shouldClientReset` and `isRecoveryModeDisabled`.
     sync_error.server_requests_action = error.server_requests_action;
     sync_error.is_unrecognized_by_client = unrecognized_by_client;
+    sync_error.user_code_error = error.user_code_error;
 
     if (delete_file)
         update_error_and_mark_file_for_deletion(sync_error, *delete_file);

src/realm/sync/client_base.hpp

@@ -265,6 +265,7 @@ struct SessionErrorInfo : public ProtocolErrorInfo {
     }
 
     Status status;
+    void* user_code_error = nullptr;
 };
 
 enum class ConnectionState { disconnected, connecting, connected };

src/realm/sync/config.hpp

@@ -82,6 +82,8 @@ struct SyncError {
 
     /// The error indicates a client reset situation.
     bool is_client_reset_requested() const;
+
+    void* user_code_error = nullptr;
 };
 
 using SyncSessionErrorHandler = void(std::shared_ptr<SyncSession>, SyncError);

src/realm/sync/noinst/client_impl_base.cpp

@@ -2294,6 +2294,14 @@ Status Session::receive_ident_message(SaltedFileIdent client_file_ident)
     try {
         did_client_reset = client_reset_if_needed();
     }
+    catch (const UserCodeCallbackError& e) {
+        auto err_msg = util::format("A fatal error occurred during client reset: '%1'", e.what());
+        logger.error(err_msg.c_str());
+        SessionErrorInfo err_info(Status{ErrorCodes::AutoClientResetFailed, err_msg}, IsFatal{true});
+        err_info.user_code_error = e.user_code_error;
+        suspend(err_info);
+        return Status::OK();
+    }
     catch (const std::exception& e) {
         auto err_msg = util::format("A fatal error occurred during client reset: '%1'", e.what());
         logger.error(err_msg.c_str());