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Diffstat (limited to 'host/lib/transport/udp_zero_copy.cpp')
| -rw-r--r-- | host/lib/transport/udp_zero_copy.cpp | 312 |
1 files changed, 312 insertions, 0 deletions
diff --git a/host/lib/transport/udp_zero_copy.cpp b/host/lib/transport/udp_zero_copy.cpp new file mode 100644 index 000000000..e43a96dd0 --- /dev/null +++ b/host/lib/transport/udp_zero_copy.cpp @@ -0,0 +1,312 @@ +// +// Copyright 2010-2011 Ettus Research LLC +// +// This program 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 of the License, or +// (at your option) any later version. +// +// This program 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, see <http://www.gnu.org/licenses/>. +// + +#include "udp_common.hpp" +#include <uhd/transport/udp_zero_copy.hpp> +#include <uhd/transport/udp_simple.hpp> //mtu +#include <uhd/transport/bounded_buffer.hpp> +#include <uhd/transport/buffer_pool.hpp> +#include <uhd/utils/msg.hpp> +#include <uhd/utils/log.hpp> +#include <boost/format.hpp> +#include <list> + +using namespace uhd; +using namespace uhd::transport; +namespace asio = boost::asio; + +//A reasonable number of frames for send/recv and async/sync +static const size_t DEFAULT_NUM_FRAMES = 32; + +/*********************************************************************** + * Check registry for correct fast-path setting (windows only) + **********************************************************************/ +#ifdef UHD_PLATFORM_WIN32 +#include <atlbase.h> //CRegKey +static void check_registry_for_fast_send_threshold(const size_t mtu){ + static bool warned = false; + if (warned) return; //only allow one printed warning per process + + CRegKey reg_key; + DWORD threshold = 1024; //system default when threshold is not specified + if ( + reg_key.Open(HKEY_LOCAL_MACHINE, "System\\CurrentControlSet\\Services\\AFD\\Parameters", KEY_READ) != ERROR_SUCCESS or + reg_key.QueryDWORDValue("FastSendDatagramThreshold", threshold) != ERROR_SUCCESS or threshold < mtu + ){ + UHD_MSG(warning) << boost::format( + "The MTU (%d) is larger than the FastSendDatagramThreshold (%d)!\n" + "This will negatively affect the transmit performance.\n" + "See the transport application notes for more detail.\n" + ) % mtu % threshold << std::endl; + warned = true; + } + reg_key.Close(); +} +#endif /*UHD_PLATFORM_WIN32*/ + +/*********************************************************************** + * Reusable managed receiver buffer: + * - Initialize with memory and a release callback. + * - Call get new with a length in bytes to re-use. + **********************************************************************/ +class udp_zero_copy_asio_mrb : public managed_recv_buffer{ +public: + udp_zero_copy_asio_mrb(void *mem, bounded_buffer<udp_zero_copy_asio_mrb *> &pending): + _mem(mem), _len(0), _pending(pending){/* NOP */} + + void release(void){ + if (_len == 0) return; + _pending.push_with_haste(this); + _len = 0; + } + + sptr get_new(size_t len){ + _len = len; + return make_managed_buffer(this); + } + + template <class T> T cast(void) const{return static_cast<T>(_mem);} + +private: + const void *get_buff(void) const{return _mem;} + size_t get_size(void) const{return _len;} + + void *_mem; + size_t _len; + bounded_buffer<udp_zero_copy_asio_mrb *> &_pending; +}; + +/*********************************************************************** + * Reusable managed send buffer: + * - Initialize with memory and a commit callback. + * - Call get new with a length in bytes to re-use. + **********************************************************************/ +class udp_zero_copy_asio_msb : public managed_send_buffer{ +public: + udp_zero_copy_asio_msb(void *mem, bounded_buffer<udp_zero_copy_asio_msb *> &pending, int sock_fd): + _mem(mem), _len(0), _pending(pending), _sock_fd(sock_fd){/* NOP */} + + void commit(size_t len){ + if (_len == 0) return; + ::send(_sock_fd, this->cast<const char *>(), len, 0); + _pending.push_with_haste(this); + _len = 0; + } + + sptr get_new(size_t len){ + _len = len; + return make_managed_buffer(this); + } + +private: + void *get_buff(void) const{return _mem;} + size_t get_size(void) const{return _len;} + + void *_mem; + size_t _len; + bounded_buffer<udp_zero_copy_asio_msb *> &_pending; + int _sock_fd; +}; + +/*********************************************************************** + * Zero Copy UDP implementation with ASIO: + * This is the portable zero copy implementation for systems + * where a faster, platform specific solution is not available. + * However, it is not a true zero copy implementation as each + * send and recv requires a copy operation to/from userspace. + **********************************************************************/ +class udp_zero_copy_asio_impl : public udp_zero_copy{ +public: + typedef boost::shared_ptr<udp_zero_copy_asio_impl> sptr; + + udp_zero_copy_asio_impl( + const std::string &addr, + const std::string &port, + const device_addr_t &hints + ): + _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))), + _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))), + _recv_buffer_pool(buffer_pool::make(_num_recv_frames, _recv_frame_size)), + _send_buffer_pool(buffer_pool::make(_num_send_frames, _send_frame_size)), + _pending_recv_buffs(_num_recv_frames), + _pending_send_buffs(_num_send_frames) + { + UHD_LOG << boost::format("Creating udp transport for %s %s") % addr % port << std::endl; + + #ifdef UHD_PLATFORM_WIN32 + check_registry_for_fast_send_threshold(this->get_send_frame_size()); + #endif /*UHD_PLATFORM_WIN32*/ + + //resolve the address + asio::ip::udp::resolver resolver(_io_service); + asio::ip::udp::resolver::query query(asio::ip::udp::v4(), addr, port); + asio::ip::udp::endpoint receiver_endpoint = *resolver.resolve(query); + + //create, open, and connect the socket + _socket = socket_sptr(new asio::ip::udp::socket(_io_service)); + _socket->open(asio::ip::udp::v4()); + _socket->connect(receiver_endpoint); + _sock_fd = _socket->native(); + + //allocate re-usable managed receive buffers + for (size_t i = 0; i < get_num_recv_frames(); i++){ + _mrb_pool.push_back(udp_zero_copy_asio_mrb( + _recv_buffer_pool->at(i), _pending_recv_buffs + )); + _pending_recv_buffs.push_with_haste(&_mrb_pool.back()); + } + + //allocate re-usable managed send buffers + for (size_t i = 0; i < get_num_send_frames(); i++){ + _msb_pool.push_back(udp_zero_copy_asio_msb( + _send_buffer_pool->at(i), _pending_send_buffs, _sock_fd + )); + _pending_send_buffs.push_with_haste(&_msb_pool.back()); + } + } + + //get size for internal socket buffer + template <typename Opt> size_t get_buff_size(void) const{ + Opt option; + _socket->get_option(option); + return option.value(); + } + + //set size for internal socket buffer + template <typename Opt> size_t resize_buff(size_t num_bytes){ + Opt option(num_bytes); + _socket->set_option(option); + return get_buff_size<Opt>(); + } + + /******************************************************************* + * Receive implementation: + * + * Perform a non-blocking receive for performance, + * and then fall back to a blocking receive with timeout. + * Return the managed receive buffer with the new length. + * When the caller is finished with the managed buffer, + * the managed receive buffer is released back into the queue. + ******************************************************************/ + managed_recv_buffer::sptr get_recv_buff(double timeout){ + udp_zero_copy_asio_mrb *mrb = NULL; + if (_pending_recv_buffs.pop_with_timed_wait(mrb, timeout)){ + + #ifdef MSG_DONTWAIT //try a non-blocking recv() if supported + ssize_t ret = ::recv(_sock_fd, mrb->cast<char *>(), _recv_frame_size, MSG_DONTWAIT); + if (ret > 0) return mrb->get_new(ret); + #endif + + if (wait_for_recv_ready(_sock_fd, timeout)) return mrb->get_new( + ::recv(_sock_fd, mrb->cast<char *>(), _recv_frame_size, 0) + ); + + _pending_recv_buffs.push_with_haste(mrb); //timeout: return the managed buffer to the queue + } + return managed_recv_buffer::sptr(); + } + + size_t get_num_recv_frames(void) const {return _num_recv_frames;} + size_t get_recv_frame_size(void) const {return _recv_frame_size;} + + /******************************************************************* + * Send implementation: + * + * Get a managed receive buffer immediately with max length set. + * The caller will fill the buffer and commit it when finished. + * The commit routine will perform a blocking send operation, + * and push the managed send buffer back into the queue. + ******************************************************************/ + managed_send_buffer::sptr get_send_buff(double timeout){ + udp_zero_copy_asio_msb *msb = NULL; + if (_pending_send_buffs.pop_with_timed_wait(msb, timeout)){ + return msb->get_new(_send_frame_size); + } + 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: + //memory management -> buffers and fifos + const size_t _recv_frame_size, _num_recv_frames; + const size_t _send_frame_size, _num_send_frames; + buffer_pool::sptr _recv_buffer_pool, _send_buffer_pool; + bounded_buffer<udp_zero_copy_asio_mrb *> _pending_recv_buffs; + bounded_buffer<udp_zero_copy_asio_msb *> _pending_send_buffs; + std::list<udp_zero_copy_asio_msb> _msb_pool; + std::list<udp_zero_copy_asio_mrb> _mrb_pool; + + //asio guts -> socket and service + asio::io_service _io_service; + socket_sptr _socket; + int _sock_fd; +}; + +/*********************************************************************** + * UDP zero copy make function + **********************************************************************/ +template<typename Opt> static void resize_buff_helper( + udp_zero_copy_asio_impl::sptr udp_trans, + const size_t target_size, + const std::string &name +){ + std::string help_message; + #if defined(UHD_PLATFORM_LINUX) + help_message = str(boost::format( + "Please run: sudo sysctl -w net.core.%smem_max=%d\n" + ) % ((name == "recv")?"r":"w") % target_size); + #endif /*defined(UHD_PLATFORM_LINUX)*/ + + //resize the buffer if size was provided + if (target_size > 0){ + size_t actual_size = udp_trans->resize_buff<Opt>(target_size); + UHD_LOG << boost::format( + "Target %s sock buff size: %d bytes\n" + "Actual %s sock buff size: %d bytes" + ) % name % target_size % name % actual_size << std::endl; + if (actual_size < target_size) UHD_MSG(warning) << boost::format( + "The %s buffer could not be resized sufficiently.\n" + "Target sock buff size: %d bytes.\n" + "Actual sock buff size: %d bytes.\n" + "See the transport application notes on buffer resizing.\n%s" + ) % name % target_size % actual_size % help_message; + } +} + +udp_zero_copy::sptr udp_zero_copy::make( + const std::string &addr, + const std::string &port, + const device_addr_t &hints +){ + udp_zero_copy_asio_impl::sptr udp_trans( + new udp_zero_copy_asio_impl(addr, port, hints) + ); + + //extract buffer size hints from the device addr + size_t recv_buff_size = size_t(hints.cast<double>("recv_buff_size", 0.0)); + size_t send_buff_size = size_t(hints.cast<double>("send_buff_size", 0.0)); + + //call the helper to resize send and recv buffers + resize_buff_helper<asio::socket_base::receive_buffer_size>(udp_trans, recv_buff_size, "recv"); + resize_buff_helper<asio::socket_base::send_buffer_size> (udp_trans, send_buff_size, "send"); + + return udp_trans; +} |