introducing a generic logger "class"

common/utils/T/tracer/logger/logger_defs.h

@@ -0,0 +1,14 @@
+#ifndef _LOGGER_DEFS_H_
+#define _LOGGER_DEFS_H_
+
+#include "view/view.h"
+
+struct logger {
+  char *event_name;
+  unsigned long handler_id;
+  /* list of views */
+  view **v;
+  int vsize;
+};
+
+#endif /* _LOGGER_DEFS_H_ */