sort of working latency tester

2 files changed, 199 insertions, 0 deletions

diff --git a/host/examples/CMakeLists.txt b/host/examples/CMakeLists.txt
index ac131b217..47152a88a 100644
--- a/host/examples/CMakeLists.txt
+++ b/host/examples/CMakeLists.txt
@@ -27,6 +27,7 @@ SET(example_sources
     test_pps_input.cpp
     tx_timed_samples.cpp
     tx_waveforms.cpp
+    latency_test.cpp
 )
 
 #for each source: build an executable and install
diff --git a/host/examples/latency_test.cpp b/host/examples/latency_test.cpp
new file mode 100644
index 000000000..596087d75
--- /dev/null
+++ b/host/examples/latency_test.cpp
@@ -0,0 +1,198 @@
+//
+// 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 <uhd/utils/thread_priority.hpp>
+#include <uhd/utils/safe_main.hpp>
+#include <uhd/usrp/single_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;
+    double wait_time;
+    size_t total_num_samps;
+    size_t samps_per_packet;
+    double rate, freq;
+    float ampl;
+
+    //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")
+        ("secs", po::value<double>(&wait_time)->default_value(0.1), "number of seconds in the future to transmit")
+        ("nsamps", po::value<size_t>(&total_num_samps)->default_value(100), "total number of samples to transmit")
+        ("spp", po::value<size_t>(&samps_per_packet)->default_value(1000), "number of samples per packet")
+        ("rate", po::value<double>(&rate)->default_value(100e6/4), "rate of outgoing samples")
+        ("freq", po::value<double>(&freq)->default_value(0), "rf center frequency in Hz")
+        ("ampl", po::value<float>(&ampl)->default_value(float(0.3)), "amplitude of each sample")
+        ("dilv", "specify to disable 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("Latency Test %s") % desc << std::endl;
+        return ~0;
+    }
+
+    bool verbose = vm.count("dilv") == 0;
+
+    //create a usrp device
+    std::cout << std::endl;
+    //std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
+    uhd::usrp::single_usrp::sptr sdev = uhd::usrp::single_usrp::make(args);
+    uhd::device::sptr dev = sdev->get_device();
+    //std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
+
+    //set the tx sample rate
+    sdev->set_tx_rate(rate);
+    std::cout << boost::format("Actual TX Rate: %f Msps...") % (sdev->get_tx_rate()/1e6) << std::endl;
+
+    //set the rx sample rate
+    sdev->set_rx_rate(rate);
+    std::cout << boost::format("Actual RX Rate: %f Msps...") % (sdev->get_rx_rate()/1e6) << std::endl;
+
+    //allocate data to send
+    std::vector<std::complex<float> > txbuff(samps_per_packet, std::complex<float>(ampl, ampl));
+
+    //allocate receive buffer
+    std::vector<std::complex<float> > rxbuff(samps_per_packet, std::complex<float>(ampl, ampl));
+
+
+    int time_error = 0;
+    int ack = 0;
+    int underflow = 0;
+    int other = 0;
+    // **************************************************
+    if(verbose)
+      std::cout << boost::format("Setting device timestamp to 0...") << std::endl;
+    sdev->set_time_now(uhd::time_spec_t(0.0));
+
+    //setup streaming
+    std::cout << std::endl;
+    if(verbose)
+      std::cout << boost::format(
+        "Begin receiving %u samples, %f seconds in the future..."
+    ) % total_num_samps % wait_time << std::endl;
+    
+    uhd::stream_cmd_t stream_cmd(uhd::stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE);
+    stream_cmd.num_samps = total_num_samps;
+    stream_cmd.stream_now = false;
+
+    double delta_t = 0.0001;
+    uhd::tx_metadata_t tx_md;
+
+    size_t num_packets = (total_num_samps+samps_per_packet-1)/samps_per_packet;
+
+
+    double cur_time = 0.0;
+    sdev->set_time_now(uhd::time_spec_t(cur_time));
+
+    for(int j=0;j<100;j++) {
+      cur_time += wait_time;
+      stream_cmd.time_spec = uhd::time_spec_t(cur_time);
+      sdev->issue_stream_cmd(stream_cmd);
+      size_t num_acc_samps = 0;
+      uhd::rx_metadata_t rx_md;
+      while(num_acc_samps < total_num_samps){
+        std::vector<std::complex<float> > rxbuff(dev->get_max_recv_samps_per_packet());
+        size_t num_rx_samps = dev->recv(
+					&rxbuff.front(), rxbuff.size(), rx_md,
+					uhd::io_type_t::COMPLEX_FLOAT32,
+					uhd::device::RECV_MODE_ONE_PACKET
+					);
+	
+        switch(rx_md.error_code){
+        case uhd::rx_metadata_t::ERROR_CODE_NONE:
+	  break;
+        case uhd::rx_metadata_t::ERROR_CODE_TIMEOUT:
+	  if (num_acc_samps == 0) continue;
+	  std::cout << boost::format
+	    ("Got timeout before all samples received, possible packet loss, exiting loop...") << std::endl;
+	  goto done_loop;
+        default:
+	  std::cout << boost::format("Got error code 0x%x, exiting loop...") % rx_md.error_code << std::endl;
+	  goto done_loop;
+        }
+	
+        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;
+	
+        num_acc_samps += num_rx_samps;
+      } done_loop:
+      
+      if(verbose) std::cout << "Done receiving samps" << std::endl;
+      
+      for (size_t i = 0; i < num_packets; i++){
+        //setup the metadata flags per fragment
+        tx_md.start_of_burst = (i == 0);              //only first packet has SOB
+        tx_md.end_of_burst   = (i == num_packets-1);  //only last packet has EOB
+        tx_md.has_time_spec  = (i == 0);              //only first packet has time
+	
+        size_t samps_to_send = std::min(total_num_samps - samps_per_packet*i, samps_per_packet);
+	
+        //send the entire packet (driver fragments internally)
+	tx_md.time_spec = uhd::time_spec_t(cur_time+delta_t);
+        size_t num_tx_samps = dev->send
+	  (&txbuff.front(), samps_to_send, tx_md,
+	   uhd::io_type_t::COMPLEX_FLOAT32,
+	   uhd::device::SEND_MODE_FULL_BUFF,
+	   //send will backup into the host this many seconds before sending:
+	   cur_time + delta_t + 0.1 //timeout (delay before transmit + padding)
+	   );
+        if (num_tx_samps < samps_to_send) std::cout << "Send timeout..." << std::endl;
+        if(verbose)
+	  std::cout << std::endl << boost::format("Sent %d samples") % num_tx_samps << std::endl;
+      }
+      
+      uhd::async_metadata_t async_md;
+      if (not dev->recv_async_msg(async_md)){
+	std::cout << boost::format
+	  ("failed:\n    Async message recv timed out.\n") << std::endl;
+      } else {
+	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;
+	}     
+      }
+    }
+    std::cout << boost::format("ACK %d, UNDERFLOW %d, TIME_ERR %d, other %d") % ack 
+      % underflow % time_error % other << std::endl;
+}