diff options
| -rw-r--r-- | host/lib/transport/udp_zero_copy_asio.cpp | 140 |
1 files changed, 101 insertions, 39 deletions
diff --git a/host/lib/transport/udp_zero_copy_asio.cpp b/host/lib/transport/udp_zero_copy_asio.cpp index 7e28caf2d..798cc657d 100644 --- a/host/lib/transport/udp_zero_copy_asio.cpp +++ b/host/lib/transport/udp_zero_copy_asio.cpp @@ -35,6 +35,10 @@ namespace asio = boost::asio; /*********************************************************************** * Constants **********************************************************************/ +//Define this to the the boost async io calls to perform receive. +//Otherwise, get_recv_buff uses a blocking receive with timeout. +//#define USE_ASIO_ASYNC_RECV + //enough buffering for half a second of samples at full rate on usrp2 static const size_t MIN_RECV_SOCK_BUFF_SIZE = size_t(4 * 25e6 * 0.5); @@ -43,8 +47,15 @@ static const size_t MIN_RECV_SOCK_BUFF_SIZE = size_t(4 * 25e6 * 0.5); //but may change with host-based flow control. static const size_t MIN_SEND_SOCK_BUFF_SIZE = size_t(10e3); -//the number of async frames to allocate for each send and recv -static const size_t DEFAULT_NUM_FRAMES = 32; +//The number of async frames to allocate for each send and recv: +//The non-async recv can have a very large number of recv frames +//because the CPU overhead is independent of the number of frames. +#ifdef USE_ASIO_ASYNC_RECV +static const size_t DEFAULT_NUM_RECV_FRAMES = 32; +#else +static const size_t DEFAULT_NUM_RECV_FRAMES = MIN_RECV_SOCK_BUFF_SIZE/udp_simple::mtu; +#endif +static const size_t DEFAULT_NUM_SEND_FRAMES = 32; //a single concurrent thread for io_service seems to be the fastest static const size_t CONCURRENCY_HINT = 1; @@ -67,9 +78,9 @@ public: ): _io_service(hints.cast<size_t>("concurrency_hint", CONCURRENCY_HINT)), _recv_frame_size(size_t(hints.cast<double>("recv_frame_size", udp_simple::mtu))), - _num_recv_frames(size_t(hints.cast<double>("num_recv_frames", DEFAULT_NUM_FRAMES))), + _num_recv_frames(size_t(hints.cast<double>("num_recv_frames", DEFAULT_NUM_RECV_FRAMES))), _send_frame_size(size_t(hints.cast<double>("send_frame_size", udp_simple::mtu))), - _num_send_frames(size_t(hints.cast<double>("num_send_frames", DEFAULT_NUM_FRAMES))) + _num_send_frames(size_t(hints.cast<double>("num_send_frames", DEFAULT_NUM_SEND_FRAMES))) { //std::cout << boost::format("Creating udp transport for %s %s") % addr % port << std::endl; @@ -82,6 +93,13 @@ public: _socket = new asio::ip::udp::socket(_io_service); _socket->open(asio::ip::udp::v4()); _socket->connect(receiver_endpoint); + _sock_fd = _socket->native(); + } + + ~udp_zero_copy_asio_impl(void){ + delete _work; //allow io_service run to complete + _thread_group.join_all(); //wait for service threads to exit + delete _socket; } void init(void){ @@ -106,10 +124,9 @@ public: ); } - ~udp_zero_copy_asio_impl(void){ - delete _work; //allow io_service run to complete - _thread_group.join_all(); //wait for service threads to exit - delete _socket; + void service(void){ + set_thread_priority_safe(); + _io_service.run(); } //get size for internal socket buffer @@ -126,6 +143,9 @@ public: return get_buff_size<Opt>(); } + //////////////////////////////////////////////////////////////////// + #ifdef USE_ASIO_ASYNC_RECV + //////////////////////////////////////////////////////////////////// //! pop a filled recv buffer off of the fifo and bind with the release callback managed_recv_buffer::sptr get_recv_buff(double timeout){ boost::this_thread::disable_interruption di; //disable because the wait can throw @@ -142,6 +162,74 @@ public: return managed_recv_buffer::sptr(); } + //! handle a recv callback -> push the filled memory into the fifo + void handle_recv(void *mem, size_t len){ + boost::this_thread::disable_interruption di; //disable because the wait can throw + _pending_recv_buffs->push_with_wait(boost::asio::buffer(mem, len)); + } + + //! release a recv buffer -> start an async recv on the buffer + void release(void *mem){ + _socket->async_receive( + boost::asio::buffer(mem, _recv_frame_size), + boost::bind( + &udp_zero_copy_asio_impl::handle_recv, + shared_from_this(), mem, + asio::placeholders::bytes_transferred + ) + ); + } + + //////////////////////////////////////////////////////////////////// + #else /*USE_ASIO_ASYNC_RECV*/ + //////////////////////////////////////////////////////////////////// + managed_recv_buffer::sptr get_recv_buff(double timeout){ + boost::this_thread::disable_interruption di; //disable because the wait can throw + + //setup timeval for timeout + timeval tv; + tv.tv_sec = 0; + tv.tv_usec = timeout*1e6; + + //setup rset for timeout + fd_set rset; + FD_ZERO(&rset); + FD_SET(_sock_fd, &rset); + + //call select to perform timed wait + if (::select(_sock_fd+1, &rset, NULL, NULL, &tv) <= 0) + return managed_recv_buffer::sptr(); + + //grab an available buffer + asio::mutable_buffer buff; + if (not _pending_recv_buffs->pop_with_timed_wait(buff, timeout)) + return managed_recv_buffer::sptr(); + + //receive and return the buffer + return managed_recv_buffer::make_safe( + asio::buffer( + boost::asio::buffer_cast<void *>(buff), + _socket->receive(boost::asio::buffer(buff)) + ), + boost::bind( + &udp_zero_copy_asio_impl::release, + shared_from_this(), + asio::buffer_cast<void*>(buff) + ) + ); + } + + void release(void *mem){ + boost::this_thread::disable_interruption di; //disable because the wait can throw + _pending_recv_buffs->push_with_wait( + boost::asio::buffer(mem, this->get_recv_frame_size()) + ); + } + + //////////////////////////////////////////////////////////////////// + #endif /*USE_ASIO_ASYNC_RECV*/ + //////////////////////////////////////////////////////////////////// + size_t get_num_recv_frames(void) const {return _num_recv_frames;} size_t get_recv_frame_size(void) const {return _recv_frame_size;} @@ -161,37 +249,6 @@ public: return managed_send_buffer::sptr(); } - size_t get_num_send_frames(void) const {return _num_send_frames;} - size_t get_send_frame_size(void) const {return _send_frame_size;} - -private: - void service(void){ - set_thread_priority_safe(); - _io_service.run(); - } - - /******************************************************************* - * The async send and receive callbacks - ******************************************************************/ - - //! handle a recv callback -> push the filled memory into the fifo - void handle_recv(void *mem, size_t len){ - boost::this_thread::disable_interruption di; //disable because the wait can throw - _pending_recv_buffs->push_with_wait(boost::asio::buffer(mem, len)); - } - - //! release a recv buffer -> start an async recv on the buffer - void release(void *mem){ - _socket->async_receive( - boost::asio::buffer(mem, _recv_frame_size), - boost::bind( - &udp_zero_copy_asio_impl::handle_recv, - shared_from_this(), mem, - asio::placeholders::bytes_transferred - ) - ); - } - //! handle a send callback -> push the emptied memory into the fifo void handle_send(void *mem){ boost::this_thread::disable_interruption di; //disable because the wait can throw @@ -209,10 +266,15 @@ private: ); } + size_t get_num_send_frames(void) const {return _num_send_frames;} + size_t get_send_frame_size(void) const {return _send_frame_size;} + +private: //asio guts -> socket and service asio::ip::udp::socket *_socket; asio::io_service _io_service; asio::io_service::work *_work; + asio::ip::udp::socket::native_type _sock_fd; //memory management -> buffers and fifos boost::thread_group _thread_group; |