fix comments2

Author: DanLiu2Intel

src/plugins/intel_npu/src/compiler_adapter/include/compiler.h

@@ -1,6 +1,5 @@
-//
-// Copyright (C) 2023 Intel Corporation.
-// SPDX-License-Identifier: Apache 2.0
+// Copyright (C) 2018-2025 Intel Corporation
+// SPDX-License-Identifier: Apache-2.0
 //
 
 #ifndef VPUX_COMPILER_L0_H

src/plugins/intel_npu/src/compiler_adapter/include/compiler_impl.hpp

@@ -5,6 +5,7 @@
 #pragma once
 
 #include <memory>
+#include <mutex>
 
 #include "compiler.h"
 #include "intel_npu/common/filtered_config.hpp"
@@ -23,7 +24,15 @@ class VCLCompilerImpl final : public intel_npu::ICompiler {
     ~VCLCompilerImpl() override;
 
     static std::shared_ptr<VCLCompilerImpl> getInstance() {
-        static std::shared_ptr<VCLCompilerImpl> compiler = std::make_shared<VCLCompilerImpl>();
+        static std::mutex mutex;
+        static std::weak_ptr<VCLCompilerImpl> weak_compiler;
+
+        std::lock_guard<std::mutex> lock(mutex);
+        auto compiler = weak_compiler.lock();
+        if (!compiler) {
+            compiler = std::make_shared<VCLCompilerImpl>();
+            weak_compiler = compiler;
+        }
         return compiler;
     }
 

src/plugins/intel_npu/src/compiler_adapter/src/graph.cpp

@@ -157,10 +157,6 @@ void Graph::set_argument_value(uint32_t argi, const void* argv) const {
 }
 
 void Graph::initialize(const Config& config) {
-    if (!_zeroInitStruct) {
-        _logger.warning("_zeroInitStruct is nullptr!");
-        return;
-    }
     _logger.debug("Graph initialize start");
 
     if (_zeGraphExt == nullptr || _graphDesc._handle == nullptr) {

src/plugins/intel_npu/src/compiler_adapter/src/plugin_compiler_adapter.cpp

@@ -140,12 +140,16 @@ std::shared_ptr<IGraph> PluginCompilerAdapter::compile(const std::shared_ptr<con
             graphDesc = _zeGraphExt->getGraphDescriptor(tensor.data(), tensor.get_byte_size());
             networkMeta = _zeGraphExt->getNetworkMeta(graphDesc);
             networkMeta.name = model->get_friendly_name();
+        } catch (const std::exception& ex) {
+            _logger.info("Failed to use the level zero graph handle: %s. Inference requests for this model are not "
+                         "allowed. Only exports are available",
+                         ex.what());
         } catch (...) {
             _logger.info("Failed to obtain the level zero graph handle. Inference requests for this model are not "
                          "allowed. Only exports are available");
         }
     } else {
-        _logger.warning("no zeGraphExt, metadata is empty from vcl compiler");
+        _logger.warning("No driver is found, zeGraphExt is nullptr, so metadata is empty. Only exports are available");
     }
 
     return std::make_shared<Graph>(

src/plugins/intel_npu/src/compiler_adapter/src/weightless_utils.cpp

@@ -2,8 +2,6 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 
-#pragma once
-
 #include "weightless_utils.hpp"
 
 #include "openvino/core/rt_info/weightless_caching_attributes.hpp"