Fix structure of EpLibraryPlugin::Load so that we call Unload on error.

onnxruntime/core/session/plugin_ep/ep_library_plugin.cc

@@ -11,41 +11,56 @@
 Status EpLibraryPlugin::Load() {
   auto status = Status::OK();
 
-  std::lock_guard<std::mutex> lock{mutex_};
   ORT_TRY {
+    std::lock_guard<std::mutex> lock{mutex_};
     if (factories_.empty()) {
-      ORT_RETURN_IF_ERROR(Env::Default().LoadDynamicLibrary(library_path_, false, &handle_));
-      ORT_RETURN_IF_ERROR(Env::Default().GetSymbolFromLibrary(handle_, "CreateEpFactories",
-                                                              reinterpret_cast<void**>(&create_fn_)));
-      ORT_RETURN_IF_ERROR(Env::Default().GetSymbolFromLibrary(handle_, "ReleaseEpFactory",
-                                                              reinterpret_cast<void**>(&release_fn_)));
-
-      // allocate buffer for EP to add factories to. library can add up to 4 factories.
-      std::vector<OrtEpFactory*> factories{4, nullptr};
-
-      size_t num_factories = 0;
-      ORT_RETURN_IF_ERROR(ToStatusAndRelease(create_fn_(registration_name_.c_str(), OrtGetApiBase(),
-                                                        logging::LoggingManager::DefaultLogger().ToExternal(),
-                                                        factories.data(), factories.size(), &num_factories)));
-
-      for (size_t i = 0; i < num_factories; ++i) {
-        factories_.push_back(factories[i]);
-      }
+      // Run the load steps in an inner lambda so that an early error return from ORT_RETURN_IF_ERROR
+      // is captured in `status` rather than returning out of this function. That lets the cleanup
+      // below run on ANY failure path (error status or exception). Previously the ORT_RETURN_IF_ERROR
+      // returns bypassed the ORT_CATCH cleanup, so a partial load - e.g. the library handle was
+      // acquired but a required export was missing or CreateEpFactories failed - left the library
+      // loaded and half-initialized.
+      status = [&]() -> Status {
+        ORT_RETURN_IF_ERROR(Env::Default().LoadDynamicLibrary(library_path_, false, &handle_));
+        ORT_RETURN_IF_ERROR(Env::Default().GetSymbolFromLibrary(handle_, "CreateEpFactories",
+                                                                reinterpret_cast<void**>(&create_fn_)));
+        ORT_RETURN_IF_ERROR(Env::Default().GetSymbolFromLibrary(handle_, "ReleaseEpFactory",
+                                                                reinterpret_cast<void**>(&release_fn_)));
+
+        // allocate buffer for EP to add factories to. library can add up to 4 factories.
+        std::vector<OrtEpFactory*> factories{4, nullptr};
+
+        size_t num_factories = 0;
+        ORT_RETURN_IF_ERROR(ToStatusAndRelease(create_fn_(registration_name_.c_str(), OrtGetApiBase(),
+                                                          logging::LoggingManager::DefaultLogger().ToExternal(),
+                                                          factories.data(), factories.size(), &num_factories)));
+
+        for (size_t i = 0; i < num_factories; ++i) {
+          factories_.push_back(factories[i]);
+        }
+
+        return Status::OK();
+      }();
     }
   }
   ORT_CATCH(const std::exception& ex) {
     ORT_HANDLE_EXCEPTION([&]() {
       // TODO: Add logging of exception
       status = ORT_MAKE_STATUS(ONNXRUNTIME, FAIL, "Failed to load execution provider library: ", library_path_,
                                " with error: ", ex.what());
-      auto unload_status = Unload();  // If anything fails we unload the library
-      if (!unload_status.IsOK()) {
-        LOGS_DEFAULT(ERROR) << "Failed to unload execution provider library: " << library_path_ << " with error: "
-                            << unload_status.ErrorMessage();
-      }
     });
   }
 
+  // If the load failed for any reason (error status or exception), unload the library so a partial
+  // load does not leave it loaded and half-initialized.
+  if (!status.IsOK()) {
+    auto unload_status = Unload();
+    if (!unload_status.IsOK()) {
+      LOGS_DEFAULT(ERROR) << "Failed to unload execution provider library: " << library_path_ << " with error: "
+                          << unload_status.ErrorMessage();
+    }
+  }
+
   return status;
 }