fixes static initialization and destruction issue

src/iss/plugin/loader.cpp

@@ -56,13 +56,12 @@
 #include "loader.h"
 
 using namespace iss::plugin;
-std::unordered_map<std::string, std::shared_ptr<loader::plugin_data>> loader::_cache;
 
 std::shared_ptr<loader::plugin_data> loader::get_data(const std::string& filepath) {
     if (filepath.empty())
         throw std::invalid_argument("failed to bind to loader: filepath was empty");
-    auto iter = _cache.find(filepath);
-    if (iter != _cache.end())
+    auto iter = get_cache().find(filepath);
+    if (iter != get_cache().end())
         return iter->second;
 #if OS_IS_WINDOWS
     auto handle = (void*)LoadLibrary(filepath.c_str());
@@ -80,7 +79,7 @@ std::shared_ptr<loader::plugin_data> loader::get_data(const std::string& filepat
                 + std::string(dlerror()));
 #endif
     auto data = std::make_shared<plugin_data>(handle, filepath);
-    _cache[filepath] = data;
+    get_cache()[filepath] = data;
     return data;
 }
 

src/iss/plugin/loader.h

@@ -111,6 +111,7 @@ class loader {
         : handle(handle), filepath(filepath) { }
 
         ~plugin_data() {
+            symbols.clear();
             if (handle) {
 #if OS_IS_WINDOWS
                 FreeLibrary((HINSTANCE)handle);
@@ -122,7 +123,11 @@ class loader {
     };
 
 private: // members
-    static std::unordered_map<std::string, std::shared_ptr<plugin_data>> _cache;
+    using cache_t = std::unordered_map<std::string, std::shared_ptr<plugin_data>>;
+    static cache_t& get_cache() {
+        static cache_t cache;
+        return cache;
+    }
     std::shared_ptr<plugin_data> _data;
     std::shared_ptr<plugin_data> get_data(const std::string &filepath);
 
@@ -141,7 +146,7 @@ class loader {
     }
 
     loader(const loader &other)
-    : _data(_cache[other.filepath()]) {
+    : _data(get_cache()[other.filepath()]) {
     }
 
     void bind_function(const std::string &label);
@@ -176,7 +181,7 @@ class loader {
     }
 
     inline loader& operator=(const loader &other) {
-        _data = _cache[other.filepath()];
+        _data = get_cache()[other.filepath()];
         return *this;
     }