Add clearBackends() method to Logger and OpmLog singleton.

opm/common/OpmLog/Logger.cpp

@@ -63,6 +63,11 @@ namespace Opm {
             return true;
     }
 
+    void Logger::clearBackends() {
+        m_backends.clear();
+        m_globalMask = 0;
+    }
+
     bool Logger::removeBackend(const std::string& name) {
         size_t eraseCount = m_backends.erase( name );
         if (eraseCount == 1)

opm/common/OpmLog/Logger.hpp

@@ -44,6 +44,7 @@ public:
     void addBackend(const std::string& name , std::shared_ptr<LogBackend> backend);
     bool hasBackend(const std::string& name);
     bool removeBackend(const std::string& name);
+    void clearBackends();
 
     template <class BackendType>
     std::shared_ptr<BackendType> getBackend(const std::string& name) const {

opm/common/OpmLog/OpmLog.cpp

@@ -96,6 +96,13 @@ namespace Opm {
     }
 
 
+    void OpmLog::clearBackends() {
+        if (m_logger) {
+            m_logger->clearBackends();
+        }
+    }
+
+
     void OpmLog::addMessageType( int64_t messageType , const std::string& prefix) {
         auto logger = OpmLog::getLogger();
         logger->addMessageType( messageType , prefix );

opm/common/OpmLog/OpmLog.hpp

@@ -50,6 +50,7 @@ public:
     static bool hasBackend( const std::string& backendName );
     static void addBackend(const std::string& name , std::shared_ptr<LogBackend> backend);
     static bool removeBackend(const std::string& name);
+    static void clearBackends();
     static bool enabledMessageType( int64_t messageType );
     static void addMessageType( int64_t messageType , const std::string& prefix);