From d54fd2abffd8849bf41a5f8084a828e6472ba342 Mon Sep 17 00:00:00 2001 From: Josh Blum Date: Mon, 11 Oct 2010 18:21:16 -0700 Subject: usrp2: use select rather than manually polling the simple udp socket --- host/include/uhd/transport/udp_simple.hpp | 4 +-- host/lib/transport/udp_simple.cpp | 44 +++++++++++++++---------------- host/lib/usrp/usrp2/usrp2_iface.cpp | 4 +-- host/lib/usrp/usrp2/usrp2_impl.cpp | 5 +--- 4 files changed, 26 insertions(+), 31 deletions(-) diff --git a/host/include/uhd/transport/udp_simple.hpp b/host/include/uhd/transport/udp_simple.hpp index c84393ecf..83f895ba9 100644 --- a/host/include/uhd/transport/udp_simple.hpp +++ b/host/include/uhd/transport/udp_simple.hpp @@ -73,10 +73,10 @@ public: * Receive into the provided buffer. * Blocks until data is received or a timeout occurs. * \param buff a mutable buffer to receive into - * \param timeout_ms the timeout in milliseconds + * \param timeout the timeout in seconds * \return the number of bytes received or zero on timeout */ - virtual size_t recv(const boost::asio::mutable_buffer &buff, size_t timeout_ms) = 0; + virtual size_t recv(const boost::asio::mutable_buffer &buff, double timeout = 0.1) = 0; }; }} //namespace diff --git a/host/lib/transport/udp_simple.cpp b/host/lib/transport/udp_simple.cpp index 89750f99d..5829b462b 100644 --- a/host/lib/transport/udp_simple.cpp +++ b/host/lib/transport/udp_simple.cpp @@ -27,23 +27,25 @@ using namespace uhd::transport; * Helper Functions **********************************************************************/ /*! - * A receive timeout for a socket: - * - * It seems that asio cannot have timeouts with synchronous io. - * However, we can implement a polling loop that will timeout. - * This is okay bacause this is the slow-path implementation. - * + * Wait for available data or timeout. * \param socket the asio socket - * \param timeout_ms the timeout in milliseconds + * \param timeout the timeout in seconds + * \return false for timeout, true for data */ -static void reasonable_recv_timeout( - boost::asio::ip::udp::socket &socket, size_t timeout_ms +static bool wait_available( + boost::asio::ip::udp::socket &socket, double timeout ){ - boost::asio::deadline_timer timer(socket.get_io_service()); - timer.expires_from_now(boost::posix_time::milliseconds(timeout_ms)); - while (not (socket.available() or timer.expires_from_now().is_negative())){ - boost::this_thread::sleep(boost::posix_time::milliseconds(1)); - } + //setup timeval for timeout + timeval tv; + tv.tv_sec = 0; + tv.tv_usec = long(timeout*1e6); + + //setup rset for timeout + fd_set rset; + FD_ZERO(&rset); + FD_SET(socket.native(), &rset); + + return ::select(socket.native()+1, &rset, NULL, NULL, &tv) > 0; } /*********************************************************************** @@ -57,7 +59,7 @@ public: //send/recv size_t send(const boost::asio::const_buffer &); - size_t recv(const boost::asio::mutable_buffer &, size_t); + size_t recv(const boost::asio::mutable_buffer &, double); private: boost::asio::ip::udp::socket *_socket; @@ -86,9 +88,8 @@ size_t udp_connected_impl::send(const boost::asio::const_buffer &buff){ return _socket->send(boost::asio::buffer(buff)); } -size_t udp_connected_impl::recv(const boost::asio::mutable_buffer &buff, size_t timeout_ms){ - reasonable_recv_timeout(*_socket, timeout_ms); - if (not _socket->available()) return 0; +size_t udp_connected_impl::recv(const boost::asio::mutable_buffer &buff, double timeout){ + if (not wait_available(*_socket, timeout)) return 0; return _socket->receive(boost::asio::buffer(buff)); } @@ -103,7 +104,7 @@ public: //send/recv size_t send(const boost::asio::const_buffer &); - size_t recv(const boost::asio::mutable_buffer &, size_t); + size_t recv(const boost::asio::mutable_buffer &, double); private: boost::asio::ip::udp::socket *_socket; @@ -137,9 +138,8 @@ size_t udp_broadcast_impl::send(const boost::asio::const_buffer &buff){ return _socket->send_to(boost::asio::buffer(buff), _receiver_endpoint); } -size_t udp_broadcast_impl::recv(const boost::asio::mutable_buffer &buff, size_t timeout_ms){ - reasonable_recv_timeout(*_socket, timeout_ms); - if (not _socket->available()) return 0; +size_t udp_broadcast_impl::recv(const boost::asio::mutable_buffer &buff, double timeout){ + if (not wait_available(*_socket, timeout)) return 0; boost::asio::ip::udp::endpoint sender_endpoint; return _socket->receive_from(boost::asio::buffer(buff), sender_endpoint); } diff --git a/host/lib/usrp/usrp2/usrp2_iface.cpp b/host/lib/usrp/usrp2/usrp2_iface.cpp index 6fdde7b2e..55c42567e 100644 --- a/host/lib/usrp/usrp2/usrp2_iface.cpp +++ b/host/lib/usrp/usrp2/usrp2_iface.cpp @@ -30,8 +30,6 @@ using namespace uhd; using namespace uhd::transport; -static const size_t CONTROL_TIMEOUT_MS = 200; - class usrp2_iface_impl : public usrp2_iface{ public: /*********************************************************************** @@ -177,7 +175,7 @@ public: boost::uint8_t usrp2_ctrl_data_in_mem[udp_simple::mtu]; //allocate max bytes for recv const usrp2_ctrl_data_t *ctrl_data_in = reinterpret_cast(usrp2_ctrl_data_in_mem); while(true){ - size_t len = _ctrl_transport->recv(boost::asio::buffer(usrp2_ctrl_data_in_mem), CONTROL_TIMEOUT_MS); + size_t len = _ctrl_transport->recv(boost::asio::buffer(usrp2_ctrl_data_in_mem)); if(len >= sizeof(boost::uint32_t) and ntohl(ctrl_data_in->proto_ver) != USRP2_FW_COMPAT_NUM){ throw std::runtime_error(str(boost::format( "Expected protocol compatibility number %d, but got %d:\n" diff --git a/host/lib/usrp/usrp2/usrp2_impl.cpp b/host/lib/usrp/usrp2/usrp2_impl.cpp index 79bf2b260..1d9f25019 100644 --- a/host/lib/usrp/usrp2/usrp2_impl.cpp +++ b/host/lib/usrp/usrp2/usrp2_impl.cpp @@ -35,9 +35,6 @@ using namespace uhd::usrp; using namespace uhd::transport; namespace asio = boost::asio; -//! wait this long for a control response when discovering devices -static const size_t DISCOVERY_TIMEOUT_MS = 100; - /*********************************************************************** * Helper Functions **********************************************************************/ @@ -99,7 +96,7 @@ static uhd::device_addrs_t usrp2_find(const device_addr_t &hint){ boost::uint8_t usrp2_ctrl_data_in_mem[udp_simple::mtu]; //allocate max bytes for recv const usrp2_ctrl_data_t *ctrl_data_in = reinterpret_cast(usrp2_ctrl_data_in_mem); while(true){ - size_t len = udp_transport->recv(asio::buffer(usrp2_ctrl_data_in_mem), DISCOVERY_TIMEOUT_MS); + size_t len = udp_transport->recv(asio::buffer(usrp2_ctrl_data_in_mem)); //std::cout << len << "\n"; if (len > offsetof(usrp2_ctrl_data_t, data)){ //handle the received data -- cgit v1.2.3