From e26acc36762650c59be8e333fd6b8b6911d8479b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Monta=C3=B1ana=20G=C3=B3mez?=
 <rmontanana@gmail.com>
Date: Mon, 30 Oct 2023 11:36:59 +0100
Subject: [PATCH] make singleton thread safe

---
 src/PyWrap.cc | 10 ++++++----
 src/PyWrap.h  |  5 ++---
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/PyWrap.cc b/src/PyWrap.cc
index c1dd263..9dca6c7 100644
--- a/src/PyWrap.cc
+++ b/src/PyWrap.cc
@@ -7,9 +7,11 @@
 
 namespace pywrap {
     PyWrap* PyWrap::wrapper = nullptr;
+    std::mutex PyWrap::mutex;
 
     PyWrap* PyWrap::GetInstance()
     {
+        std::lock_guard<std::mutex> lock(mutex);
         if (wrapper == nullptr) {
             std::cout << "Creando instancia" << std::endl;
             wrapper = new PyWrap();
@@ -35,15 +37,15 @@ namespace pywrap {
             return;
         }
         std::cout << "No estaba en el mapa" << std::endl;
-        module = PyImport_ImportModule(moduleName.c_str());
+        PyObject* module = PyImport_ImportModule(moduleName.c_str());
         if (PyErr_Occurred()) {
             errorAbort("Could't import module " + moduleName);
         }
-        classObject = PyObject_GetAttrString(module, className.c_str());
+        PyObject* classObject = PyObject_GetAttrString(module, className.c_str());
         if (PyErr_Occurred()) {
             errorAbort("Couldn't find class " + className);
         }
-        instance = PyObject_CallObject(classObject, NULL);
+        PyObject* instance = PyObject_CallObject(classObject, NULL);
         if (PyErr_Occurred()) {
             errorAbort("Couldn't create instance of class " + className);
         }
@@ -89,7 +91,7 @@ namespace pywrap {
             errorAbort("Module " + moduleName + " and class " + className + " not found");
         }
         std::cout << "Clase encontrada" << std::endl;
-        instance = std::get<2>(item->second);
+        PyObject* instance = std::get<2>(item->second);
         PyObject* result;
         if (!(result = PyObject_CallMethod(instance, method.c_str(), NULL)))
             errorAbort("Couldn't call method " + method);
diff --git a/src/PyWrap.h b/src/PyWrap.h
index a94c90a..cad4c83 100644
--- a/src/PyWrap.h
+++ b/src/PyWrap.h
@@ -4,6 +4,7 @@
 #include <string>
 #include <map>
 #include <tuple>
+#include <mutex>
 
 namespace pywrap {
     /*
@@ -24,10 +25,8 @@ namespace pywrap {
         void errorAbort(const std::string& message);
         PyStatus initPython();
         static PyWrap* wrapper;
+        static std::mutex mutex;
         std::map<std::pair<std::string, std::string>, std::tuple<PyObject*, PyObject*, PyObject*>> moduleClassMap;
-        PyObject* module;
-        PyObject* classObject;
-        PyObject* instance;
     };
 } /* namespace python */
 #endif /* PYWRAP_H */
\ No newline at end of file