move mysql init to createSession() and protect it with mutex

Data/MySQL/include/Poco/Data/MySQL/Connector.h

@@ -22,6 +22,7 @@
 
 #include "Poco/Data/MySQL/MySQL.h"
 #include "Poco/Data/Connector.h"
+#include "Poco/Mutex.h"
 
 
 // Note: to avoid static (de)initialization problems,
@@ -60,6 +61,8 @@ public:
 
 	static void unregisterConnector();
 		/// Unregisters the Connector under the Keyword Connector::KEY at the Poco::Data::SessionFactory
+
+	static Poco::Mutex _mutex;
 };
 
 

Data/MySQL/src/Connector.cpp

@@ -30,6 +30,7 @@ namespace MySQL {
 
 
 std::string Connector::KEY(POCO_DATA_MYSQL_CONNECTOR_NAME);
+Poco::Mutex Connector::_mutex;
 
 
 Connector::Connector()
@@ -50,17 +51,25 @@ const std::string& Connector::name() const
 Poco::AutoPtr<Poco::Data::SessionImpl> Connector::createSession(const std::string& connectionString,
 	std::size_t timeout)
 {
+	static bool initDone = false;
+	{
+		Poco::Mutex::ScopedLock l(_mutex);
+		if (!initDone)
+		{
+			if (mysql_library_init(0, 0, 0) != 0)
+			{
+				throw Exception("mysql_library_init error");
+			}
+			initDone = true;
+		}
+	}
+
 	return Poco::AutoPtr<Poco::Data::SessionImpl>(new SessionImpl(connectionString, timeout));	
 }
 
 
 void Connector::registerConnector()
 {
-	if (mysql_library_init(0, 0, 0) != 0)
-	{
-		throw Exception("mysql_library_init error");
-	}
-
 	Poco::Data::SessionFactory::instance().add(new Connector());
 }
 

Data/MySQL/testsuite/src/MySQLTest.cpp

@@ -49,16 +49,22 @@ Poco::SharedPtr<SQLExecutor> MySQLTest::_pExecutor = 0;
 
 std::string MySQLTest::getHost()
 {
-	return "localhost";
+	return "127.0.0.1"; //localhost";
 }
+
+
 std::string MySQLTest::getPort()
 {
 	return "3306";
 }
+
+
 std::string MySQLTest::getUser()
 {
 	return "root";
 }
+
+
 std::string MySQLTest::getPass()
 {
 	if (Environment::has("APPVEYOR"))
@@ -68,18 +74,20 @@ std::string MySQLTest::getPass()
 	else
 		return "poco";
 }
+
+
 std::string MySQLTest::getBase()
 {
 	return "pocotestdb";
 }
 
-std::string MySQLTest::_dbConnString;
 
+std::string MySQLTest::_dbConnString;
 
 
 //
 // Connection string
-
+//
 
 MySQLTest::MySQLTest(const std::string& name):
 	CppUnit::TestCase(name)