Use unique_ptr and use more namespaces

Signed-off-by: Ben Howe <[email protected]>

libs/qec/include/cudaq/qec/plugin_loader.h

@@ -6,26 +6,37 @@
  * the terms of the Apache License 2.0 which accompanies this distribution.    *
  ******************************************************************************/
 
-#ifndef PLUGIN_LOADER_H
-#define PLUGIN_LOADER_H
+#pragma once
 
 #include <dlfcn.h>
 #include <map>
 #include <memory>
 #include <string>
 
+namespace cudaq::qec {
+
 /// @brief Enum to define different types of plugins
 enum class PluginType {
   DECODER, // Decoder plugins
   CODE     // QEC codes plugins
            // Add other plugin types here as needed
 };
 
+struct PluginDeleter // deleter
+{
+  void operator()(void *h) const {
+    if (h)
+      dlclose(h);
+  };
+};
+
 /// @brief A struct to store plugin handle with its type
 struct PluginHandle {
-  std::shared_ptr<void> handle; // Pointer to the shared library handle. This is
-                                // the result of dlopen() function.
-  PluginType type;              // Type of the plugin (e.g., decoder, code, etc)
+  // Pointer to the shared library handle. This is the result of dlopen()
+  // function.
+  std::unique_ptr<void, PluginDeleter> handle;
+  // Type of the plugin (e.g., decoder, code, etc)
+  PluginType type;
 };
 
 /// @brief Function to load plugins from a directory based on type
@@ -39,4 +50,4 @@ void load_plugins(const std::string &plugin_dir, PluginType type);
 /// be cleaned up.
 void cleanup_plugins(PluginType type);
 
-#endif // PLUGIN_LOADER_H
+} // namespace cudaq::qec

libs/qec/lib/decoder.cpp

@@ -74,7 +74,6 @@ std::unique_ptr<decoder> get_decoder(const std::string &name,
                                      const cudaqx::heterogeneous_map options) {
   return decoder::get(name, H, options);
 }
-} // namespace cudaq::qec
 
 // Constructor function for auto-loading plugins
 __attribute__((constructor)) void load_decoder_plugins() {
@@ -89,4 +88,5 @@ __attribute__((constructor)) void load_decoder_plugins() {
 __attribute__((destructor)) void cleanup_decoder_plugins() {
   // Clean up decoder-specific plugins
   cleanup_plugins(PluginType::DECODER);
-}
+}
+} // namespace cudaq::qec

libs/qec/lib/plugin_loader.cpp

@@ -12,6 +12,8 @@
 
 namespace fs = std::filesystem;
 
+namespace cudaq::qec {
+
 static std::map<std::string, PluginHandle> &get_plugin_handles() {
   static std::map<std::string, PluginHandle> plugin_handles;
   return plugin_handles;
@@ -28,15 +30,11 @@ void load_plugins(const std::string &plugin_dir, PluginType type) {
     if (entry.path().extension() == ".so") {
       void *raw_handle = dlopen(entry.path().c_str(), RTLD_NOW);
       if (raw_handle) {
-        // Custom deleter ensures dlclose is called
-        auto deleter = [](void *h) {
-          if (h)
-            dlclose(h);
-        };
-
         get_plugin_handles().emplace(
             entry.path().filename().string(),
-            PluginHandle{std::shared_ptr<void>(raw_handle, deleter), type});
+            PluginHandle{std::unique_ptr<void, PluginDeleter>(raw_handle,
+                                                              PluginDeleter()),
+                         type});
       } else {
         std::cerr << "ERROR: Failed to load plugin: " << entry.path()
                   << " Error: " << dlerror() << std::endl;
@@ -57,3 +55,5 @@ void cleanup_plugins(PluginType type) {
     }
   }
 }
+
+} // namespace cudaq::qec