cta/CTA#130 Helgrind gets spurious when using `std::mutex` in the catalogue.

With respect to the rdbms::OcciConn class. Replaced std::mutex and
std::lock_guard with their helgrind friendly drop in replacements
threading::Mutex and threading::MutexLocker.

rdbms/OcciConn.cpp

@@ -18,6 +18,7 @@
 
 #include "common/exception/Exception.hpp"
 #include "common/make_unique.hpp"
+#include "common/threading/MutexLocker.hpp"
 #include "rdbms/OcciConn.hpp"
 #include "rdbms/OcciEnv.hpp"
 #include "rdbms/OcciStmt.hpp"
@@ -55,7 +56,7 @@ OcciConn::~OcciConn() throw() {
 // close
 //------------------------------------------------------------------------------
 void OcciConn::close() {
-  std::lock_guard<std::mutex> lock(m_mutex);
+  threading::MutexLocker locker(m_mutex);
 
   if(nullptr != m_occiConn) {
     m_env->terminateConnection(m_occiConn);
@@ -68,7 +69,7 @@ void OcciConn::close() {
 //------------------------------------------------------------------------------
 std::unique_ptr<Stmt> OcciConn::createStmt(const std::string &sql, Stmt::AutocommitMode autocommitMode) {
   try {
-    std::lock_guard<std::mutex> lock(m_mutex);
+    threading::MutexLocker locker(m_mutex);
 
     if(nullptr == m_occiConn) {
        throw exception::Exception("Connection is closed");
@@ -92,7 +93,7 @@ std::unique_ptr<Stmt> OcciConn::createStmt(const std::string &sql, Stmt::Autocom
 //------------------------------------------------------------------------------
 void OcciConn::commit() {
   try {
-    std::lock_guard<std::mutex> lock(m_mutex);
+    threading::MutexLocker locker(m_mutex);
 
     if(nullptr == m_occiConn) {
        throw exception::Exception("Connection is closed");
@@ -111,7 +112,7 @@ void OcciConn::commit() {
 //------------------------------------------------------------------------------
 void OcciConn::rollback() {
   try {
-    std::lock_guard<std::mutex> lock(m_mutex);
+    threading::MutexLocker locker(m_mutex);
 
     if(nullptr == m_occiConn) {
        throw exception::Exception("Connection is closed");
@@ -187,7 +188,7 @@ bool OcciConn::isOpen() const {
 //------------------------------------------------------------------------------
 void OcciConn::closeStmt(oracle::occi::Statement *const stmt) {
   try {
-    std::lock_guard<std::mutex> lock(m_mutex);
+    threading::MutexLocker locker(m_mutex);
 
     if(nullptr == m_occiConn) {
        throw exception::Exception("Connection is closed");

rdbms/OcciConn.hpp

@@ -18,10 +18,10 @@
 
 #pragma once
 
-#include "Conn.hpp"
+#include "common/threading/MutexLocker.hpp"
+#include "rdbms/Conn.hpp"
 
 #include <occi.h>
-#include <mutex>
 
 namespace cta {
 namespace rdbms {
@@ -108,7 +108,7 @@ private:
   /**
    * Mutex used to serialize access to this object.
    */
-  std::mutex m_mutex;
+  threading::Mutex m_mutex;
 
   /**
    * The OCCI environment.