Database: ref-count the internal map for caching

2 files changed, 7 insertions, 5 deletions

diff --git a/src/database/database.cpp b/src/database/database.cpp
index cf548d46..9b4e8119 100644
--- a/src/database/database.cpp
+++ b/src/database/database.cpp
@@ -65,7 +65,7 @@ const std::unordered_map<std::string, std::string> Database::kVendorNames{
 // This takes an optional overlay database in case of custom tuning or custom kernels.
 Database::Database(const Queue &queue, const std::vector<std::string> &kernels,
                    const Precision precision, const std::vector<const DatabaseEntry*> &overlay):
-  parameters_{} {
+  parameters_(std::make_shared<Parameters>()) {
 
   // Finds information of the current device
   auto device = queue.GetDevice();
@@ -87,7 +87,7 @@ Database::Database(const Queue &queue, const std::vector<std::string> &kernels,
     for (auto &db: { database, overlay}) {
       search_result = Search(kernel, device_type, device_vendor, device_name, precision, db);
       if (search_result) {
-        parameters_.insert(search_result->begin(), search_result->end());
+        parameters_->insert(search_result->begin(), search_result->end());
         break;
       }
     }
@@ -101,7 +101,7 @@ Database::Database(const Queue &queue, const std::vector<std::string> &kernels,
 // Returns a list of OpenCL pre-processor defines in string form
 std::string Database::GetDefines() const {
   std::string defines{};
-  for (auto &parameter: parameters_) {
+  for (auto &parameter: *parameters_) {
     defines += "#define "+parameter.first+" "+ToString(parameter.second)+"\n";
   }
   return defines;
diff --git a/src/database/database.hpp b/src/database/database.hpp
index 7c05a20b..92fb383c 100644
--- a/src/database/database.hpp
+++ b/src/database/database.hpp
@@ -72,12 +72,14 @@ class Database {
   // The database consists of separate database entries, stored together in a vector
   static const std::vector<const DatabaseEntry*> database;
 
+  Database() = default;
+
   // The constructor with a user-provided database overlay (potentially an empty vector)
   explicit Database(const Queue &queue, const std::vector<std::string> &routines,
                     const Precision precision, const std::vector<const DatabaseEntry*> &overlay);
 
   // Accessor of values by key
-  size_t operator[](const std::string key) const { return parameters_.find(key)->second; }
+  size_t operator[](const std::string key) const { return parameters_->find(key)->second; }
 
   // Obtain a list of OpenCL pre-processor defines based on the parameters
   std::string GetDefines() const;
@@ -90,7 +92,7 @@ class Database {
                        const std::vector<const DatabaseEntry*> &db) const;
 
   // Found parameters suitable for this device/kernel
-  Parameters parameters_;
+  std::shared_ptr<Parameters> parameters_;
 };
 
 // =================================================================================================