1 files changed, 104 insertions, 0 deletions
diff --git a/Source/cmDynamicLoader.cxx b/Source/cmDynamicLoader.cxx
new file mode 100644
index 0000000..a30b642
--- /dev/null
+++ b/Source/cmDynamicLoader.cxx
@@ -0,0 +1,104 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#include "cmDynamicLoader.h"
+
+#include <cmConfigure.h>
+
+#include <cmsys/DynamicLoader.hxx>
+#include <map>
+#include <string>
+#include <utility>
+
+class cmDynamicLoaderCache
+{
+public:
+  ~cmDynamicLoaderCache();
+  void CacheFile(const char* path,
+                 const cmsys::DynamicLoader::LibraryHandle& /*p*/);
+  bool GetCacheFile(const char* path,
+                    cmsys::DynamicLoader::LibraryHandle& /*p*/);
+  bool FlushCache(const char* path);
+  void FlushCache();
+  static cmDynamicLoaderCache* GetInstance();
+
+private:
+  std::map<std::string, cmsys::DynamicLoader::LibraryHandle> CacheMap;
+  static cmDynamicLoaderCache* Instance;
+};
+
+cmDynamicLoaderCache* cmDynamicLoaderCache::Instance = CM_NULLPTR;
+
+cmDynamicLoaderCache::~cmDynamicLoaderCache()
+{
+}
+
+void cmDynamicLoaderCache::CacheFile(
+  const char* path, const cmsys::DynamicLoader::LibraryHandle& p)
+{
+  cmsys::DynamicLoader::LibraryHandle h;
+  if (this->GetCacheFile(path, h)) {
+    this->FlushCache(path);
+  }
+  this->CacheMap[path] = p;
+}
+
+bool cmDynamicLoaderCache::GetCacheFile(const char* path,
+                                        cmsys::DynamicLoader::LibraryHandle& p)
+{
+  std::map<std::string, cmsys::DynamicLoader::LibraryHandle>::iterator it =
+    this->CacheMap.find(path);
+  if (it != this->CacheMap.end()) {
+    p = it->second;
+    return true;
+  }
+  return false;
+}
+
+bool cmDynamicLoaderCache::FlushCache(const char* path)
+{
+  std::map<std::string, cmsys::DynamicLoader::LibraryHandle>::iterator it =
+    this->CacheMap.find(path);
+  bool ret = false;
+  if (it != this->CacheMap.end()) {
+    cmsys::DynamicLoader::CloseLibrary(it->second);
+    this->CacheMap.erase(it);
+    ret = true;
+  }
+  return ret;
+}
+
+void cmDynamicLoaderCache::FlushCache()
+{
+  for (std::map<std::string, cmsys::DynamicLoader::LibraryHandle>::iterator
+         it = this->CacheMap.begin();
+       it != this->CacheMap.end(); it++) {
+    cmsys::DynamicLoader::CloseLibrary(it->second);
+  }
+  delete cmDynamicLoaderCache::Instance;
+  cmDynamicLoaderCache::Instance = CM_NULLPTR;
+}
+
+cmDynamicLoaderCache* cmDynamicLoaderCache::GetInstance()
+{
+  if (!cmDynamicLoaderCache::Instance) {
+    cmDynamicLoaderCache::Instance = new cmDynamicLoaderCache;
+  }
+  return cmDynamicLoaderCache::Instance;
+}
+
+cmsys::DynamicLoader::LibraryHandle cmDynamicLoader::OpenLibrary(
+  const char* libname)
+{
+  cmsys::DynamicLoader::LibraryHandle lh;
+  if (cmDynamicLoaderCache::GetInstance()->GetCacheFile(libname, lh)) {
+    return lh;
+  }
+  lh = cmsys::DynamicLoader::OpenLibrary(libname);
+  cmDynamicLoaderCache::GetInstance()->CacheFile(libname, lh);
+  return lh;
+}
+
+void cmDynamicLoader::FlushCache()
+{
+  cmDynamicLoaderCache::GetInstance()->FlushCache();
+}