Problem: inconsistent naming style for private data members, conflicts with naming of local variables and member functions

Solution: apply and check _lower_case naming style for private data members

src/mailbox.hpp

@@ -58,26 +58,26 @@ class mailbox_t : public i_mailbox
     // close the file descriptors in the signaller. This is used in a forked
     // child process to close the file descriptors so that they do not interfere
     // with the context in the parent process.
-    void forked () { signaler.forked (); }
+    void forked () { _signaler.forked (); }
 #endif
 
   private:
     //  The pipe to store actual commands.
     typedef ypipe_t<command_t, command_pipe_granularity> cpipe_t;
-    cpipe_t cpipe;
+    cpipe_t _cpipe;
 
     //  Signaler to pass signals from writer thread to reader thread.
-    signaler_t signaler;
+    signaler_t _signaler;
 
     //  There's only one thread receiving from the mailbox, but there
     //  is arbitrary number of threads sending. Given that ypipe requires
     //  synchronised access on both of its endpoints, we have to synchronise
     //  the sending side.
-    mutex_t sync;
+    mutex_t _sync;
 
     //  True if the underlying pipe is active, ie. when we are allowed to
     //  read commands from it.
-    bool active;
+    bool _active;
 
     //  Disable copying of mailbox_t object.
     mailbox_t (const mailbox_t &);