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Diffstat (limited to 'host/examples/latency_test.cpp')
| -rw-r--r-- | host/examples/latency_test.cpp | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/host/examples/latency_test.cpp b/host/examples/latency_test.cpp new file mode 100644 index 000000000..518d2383a --- /dev/null +++ b/host/examples/latency_test.cpp @@ -0,0 +1,168 @@ +// +// Copyright 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 <uhd/utils/thread_priority.hpp> +#include <uhd/utils/safe_main.hpp> +#include <uhd/usrp/multi_usrp.hpp> +#include <boost/program_options.hpp> +#include <boost/format.hpp> +#include <iostream> +#include <complex> + +namespace po = boost::program_options; + +int UHD_SAFE_MAIN(int argc, char *argv[]){ + uhd::set_thread_priority_safe(); + + //variables to be set by po + std::string args; + size_t nsamps; + double rate; + double rtt; + size_t nruns; + + //setup the program options + po::options_description desc("Allowed options"); + desc.add_options() + ("help", "help message") + ("args", po::value<std::string>(&args)->default_value(""), "single uhd device address args") + ("nsamps", po::value<size_t>(&nsamps)->default_value(100), "number of samples per run") + ("nruns", po::value<size_t>(&nruns)->default_value(1000), "number of tests to perform") + ("rtt", po::value<double>(&rtt)->default_value(0.001), "delay between receive and transmit (seconds)") + ("rate", po::value<double>(&rate)->default_value(100e6/4), "sample rate for receive and transmit (sps)") + ("verbose", "specify to enable inner-loop verbose") + ; + po::variables_map vm; + po::store(po::parse_command_line(argc, argv, desc), vm); + po::notify(vm); + + //print the help message + if (vm.count("help")){ + std::cout << boost::format("UHD - Latency Test %s") % desc << std::endl; + std::cout << + " Latency test receives a packet at time t,\n" + " and tries to send a packet at time t + rtt,\n" + " where rtt is the round trip time sample time\n" + " from device to host and back to the device.\n" + << std::endl; + return ~0; + } + + bool verbose = vm.count("verbose") != 0; + + //create a usrp device + std::cout << std::endl; + //std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl; + uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args); + //std::cout << boost::format("Using Device: %s") % usrp->get_pp_string() << std::endl; + + usrp->set_time_now(uhd::time_spec_t(0.0)); + + //set the tx sample rate + usrp->set_tx_rate(rate); + std::cout << boost::format("Actual TX Rate: %f Msps...") % (usrp->get_tx_rate()/1e6) << std::endl; + + //set the rx sample rate + usrp->set_rx_rate(rate); + std::cout << boost::format("Actual RX Rate: %f Msps...") % (usrp->get_rx_rate()/1e6) << std::endl; + + //allocate a buffer to use + std::vector<std::complex<float> > buffer(nsamps); + + //create RX and TX streamers + uhd::stream_args_t stream_args("fc32"); //complex floats + uhd::rx_streamer::sptr rx_stream = usrp->get_rx_stream(stream_args); + uhd::tx_streamer::sptr tx_stream = usrp->get_tx_stream(stream_args); + + //initialize result counts + int time_error = 0; + int ack = 0; + int underflow = 0; + int other = 0; + + for(size_t nrun = 0; nrun < nruns; nrun++){ + + /*************************************************************** + * Issue a stream command some time in the near future + **************************************************************/ + uhd::stream_cmd_t stream_cmd(uhd::stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE); + stream_cmd.num_samps = buffer.size(); + stream_cmd.stream_now = false; + stream_cmd.time_spec = usrp->get_time_now() + uhd::time_spec_t(0.01); + usrp->issue_stream_cmd(stream_cmd); + + /*************************************************************** + * Receive the requested packet + **************************************************************/ + uhd::rx_metadata_t rx_md; + size_t num_rx_samps = rx_stream->recv( + &buffer.front(), buffer.size(), rx_md + ); + + if(verbose) std::cout << boost::format("Got packet: %u samples, %u full secs, %f frac secs") + % num_rx_samps % rx_md.time_spec.get_full_secs() % rx_md.time_spec.get_frac_secs() << std::endl; + + /*************************************************************** + * Transmit a packet with delta time after received packet + **************************************************************/ + uhd::tx_metadata_t tx_md; + tx_md.start_of_burst = true; + tx_md.end_of_burst = true; + tx_md.has_time_spec = true; + tx_md.time_spec = rx_md.time_spec + uhd::time_spec_t(rtt); + size_t num_tx_samps = tx_stream->send( + &buffer.front(), buffer.size(), tx_md + ); + if(verbose) std::cout << boost::format("Sent %d samples") % num_tx_samps << std::endl; + + /*************************************************************** + * Check the async messages for result + **************************************************************/ + uhd::async_metadata_t async_md; + if (not usrp->get_device()->recv_async_msg(async_md)){ + std::cout << boost::format("failed:\n Async message recv timed out.\n") << std::endl; + continue; + } + switch(async_md.event_code){ + case uhd::async_metadata_t::EVENT_CODE_TIME_ERROR: + time_error++; + break; + + case uhd::async_metadata_t::EVENT_CODE_BURST_ACK: + ack++; + break; + + case uhd::async_metadata_t::EVENT_CODE_UNDERFLOW: + underflow++; + break; + + default: + std::cerr << boost::format( + "failed:\n Got unexpected event code 0x%x.\n" + ) % async_md.event_code << std::endl; + other++; + break; + } + } + + /*************************************************************** + * Print the summary + **************************************************************/ + std::cout << boost::format("\nACK %d, UNDERFLOW %d, TIME_ERR %d, other %d") + % ack % underflow % time_error % other << std::endl; + return 0; +} |