GNU Radio 3.5.1 C++ API
gr_select_handler.h
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00001 /* -*- c++ -*- */
00002 /*
00003  * Copyright 2005 Free Software Foundation, Inc.
00004  * 
00005  * This file is part of GNU Radio
00006  * 
00007  * GNU Radio is free software; you can redistribute it and/or modify
00008  * it under the terms of the GNU General Public License as published by
00009  * the Free Software Foundation; either version 3, or (at your option)
00010  * any later version.
00011  * 
00012  * GNU Radio is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  * GNU General Public License for more details.
00016  * 
00017  * You should have received a copy of the GNU General Public License
00018  * along with GNU Radio; see the file COPYING.  If not, write to
00019  * the Free Software Foundation, Inc., 51 Franklin Street,
00020  * Boston, MA 02110-1301, USA.
00021  */
00022 
00023 #ifndef INCLUDED_GR_SELECT_HANDLER_H
00024 #define INCLUDED_GR_SELECT_HANDLER_H
00025 
00026 #include <gr_core_api.h>
00027 #include <boost/shared_ptr.hpp>
00028 
00029 class gr_select_handler;
00030 typedef boost::shared_ptr<gr_select_handler> gr_select_handler_sptr;
00031 
00032 
00033 /*!
00034  * \brief Abstract handler for select based notification.
00035  * \ingroup base
00036  *
00037  * \sa gr_dispatcher
00038  */
00039 class GR_CORE_API gr_select_handler
00040 {
00041   int   d_fd;
00042 
00043 protected:
00044   gr_select_handler(int file_descriptor);
00045 
00046 public:
00047   virtual ~gr_select_handler();
00048 
00049   int fd() const { return d_fd; }
00050   int file_descriptor() const { return d_fd; }
00051 
00052   /*!
00053    * \brief Called when file_descriptor is readable.
00054    *
00055    * Called when the dispatcher detects that file_descriptor can
00056    * be read without blocking.
00057    */
00058   virtual void handle_read() = 0;
00059 
00060   /*!
00061    * \brief Called when file_descriptor is writable.
00062    *
00063    * Called when dispatcher detects that file descriptor can be 
00064    * written without blocking.
00065    */
00066   virtual void handle_write() = 0;
00067 
00068   /*!
00069    * Called each time around the dispatcher loop to determine whether
00070    * this handler's file descriptor should be added to the list on which
00071    * read events can occur.  The default method returns true, indicating
00072    * that by default, all handlers are interested in read events.
00073    */
00074   virtual bool readable() { return true; }
00075 
00076   /*!
00077    * Called each time around the dispatcher loop to determine whether
00078    * this handler's file descriptor should be added to the list on which
00079    * write events can occur.  The default method returns true, indicating
00080    * that by default, all handlers are interested in write events.
00081    */
00082   virtual bool writable() { return true; }
00083 };
00084 
00085 #endif /* INCLUDED_GR_SELECT_HANDLER_H */