Merge branch 'latency_test'

1 files changed, 167 insertions, 0 deletions

diff --git a/host/examples/latency_test.cpp b/host/examples/latency_test.cpp
new file mode 100644
index 000000000..be44aad70
--- /dev/null
+++ b/host/examples/latency_test.cpp
@@ -0,0 +1,167 @@
+//
+// 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);
+
+    //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 = usrp->get_device()->recv(
+            &buffer.front(), buffer.size(), rx_md,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_FULL_BUFF
+        );
+
+        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 = usrp->get_device()->send(
+            &buffer.front(), buffer.size(), tx_md,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::SEND_MODE_FULL_BUFF
+        );
+        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::cout << 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;
+}