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Diffstat (limited to 'vrt/lib/socket_rx_buffer.h')
| -rw-r--r-- | vrt/lib/socket_rx_buffer.h | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/vrt/lib/socket_rx_buffer.h b/vrt/lib/socket_rx_buffer.h new file mode 100644 index 000000000..053c30c12 --- /dev/null +++ b/vrt/lib/socket_rx_buffer.h @@ -0,0 +1,122 @@ +/* -*- c++ -*- */ +/* + * Copyright 2008,2009 Free Software Foundation, Inc. + * + * This file is part of GNU Radio + * + * GNU Radio is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3, or (at your option) + * any later version. + * + * GNU Radio is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ +#ifndef INCLUDED_VRT_SOCKET_RX_BUFFER_H +#define INCLUDED_VRT_SOCKET_RX_BUFFER_H + +#include <boost/utility.hpp> +#include <vector> +#include <memory> +#include <stdint.h> + +namespace vrt { + + class data_handler; + + /*! + * \brief high-performance interface to receive datagrams + * + * On many systems it should be possible to implement this on top of libpcap + * + * \internal + */ + class socket_rx_buffer : boost::noncopyable + { + + int d_fd; // socket file descriptor + bool d_using_tpring; // using kernel mapped packet ring + size_t d_buflen; // length of our buffer + uint8_t *d_buf; // packet ring + unsigned int d_frame_nr; // max frames on ring + size_t d_frame_size; // frame storage size + unsigned int d_head; // pointer to next frame + + std::vector<uint8_t *> d_ring; // pointers into buffer + + bool frame_available(); + + void inc_head() + { + if (d_head + 1 >= d_frame_nr) + d_head = 0; + else + d_head = d_head + 1; + } + + bool open(); + bool close(); + bool try_packet_ring(); + + public: + + enum result { + EB_OK, //< everything's fine + EB_ERROR, //< A non-recoverable error occurred + EB_WOULD_BLOCK, //< A timeout of 0 was specified and nothing was ready + EB_TIMED_OUT, //< The timeout expired before anything was ready + }; + + static const unsigned int MAX_PKTLEN; + static const unsigned int MIN_PKTLEN; + + /*! + * \param socket_fd file descriptor that corresponds to a socket + * \param rx_bufsize is a hint as to the number of bytes of memory + * to allocate for received ethernet frames (0 -> reasonable default) + */ + socket_rx_buffer(int socket_fd, size_t rx_bufsize = 0); + ~socket_rx_buffer(); + + /*! + * \brief Call \p f for each frame in the receive buffer. + * \param f is the frame data handler + * \param timeout (in ms) controls behavior when there are no frames to read + * + * If \p timeout is 0, rx_frames will not wait for frames if none are + * available, and f will not be invoked. If \p timeout is -1 (the + * default), rx_frames will block indefinitely until frames are + * available. If \p timeout is positive, it indicates the number of + * milliseconds to wait for a frame to become available. Once the + * timeout has expired, rx_frames will return, f never having been + * invoked. + * + * \p f will be called on each frame that is available. + * \p f returns a bit mask with one of the following set or cleared: + * + * data_handler::DONE - return from rx_frames now even though more frames + * might be available; otherwise continue if more + * frames are ready. + * + * \returns EB_OK if at least one frame was received + * \returns EB_WOULD_BLOCK if \p timeout is 0 and the call would have blocked + * \returns EB_TIMED_OUT if timeout occurred + * \returns EB_ERROR if there was an unrecoverable error. + */ + result rx_frames(data_handler *f, int timeout=-1); + + /* + * \brief Returns maximum possible number of frames in buffer + */ + unsigned int max_frames() const { return d_using_tpring ? d_frame_nr : 0; } + }; + +}; // namespace vrt + +#endif /* INCLUDED_VRT_SOCKET_RX_BUFFER_H */ |