Add support for FreeSRP

This patch adds support for both receiving and transmitting using the FreeSRP. More information on the FreeSRP can be found at: http://freesrp.org The gr-osmosdr blocks added make use of libfreesrp, the library required for interfacing with this device. The libfreesrp source code is freely available at https://github.com/freesrp/libfreesrp Usage example: osmocom_fft -a "freesrp"
2017-04-07 23:08:01 -04:00 · 2017-04-07 23:08:01 -04:00 · 5ecfa255d2
parent e9dde9afd7
commit 5ecfa255d2
21 changed files with 2716 additions and 0 deletions
--- a/1
+++ b/1
@ -6,3 +6,4 @@ Josh Blum
 SDRplay Ltd.
 Pavel Demin
 Marcus Müller
+Lukas Lao Beyer
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@ -172,6 +172,7 @@ find_package(LibAIRSPY)
 find_package(Volk)
 find_package(LibbladeRF)
 find_package(SoapySDR NO_MODULE)
+find_package(LibFreeSRP)
 find_package(Doxygen)

 if(NOT GNURADIO_RUNTIME_FOUND)
--- a/1
+++ b/1
@ -17,6 +17,7 @@ as well supports:
 * Ettus USRP Devices through Ettus UHD library
 * Fairwaves UmTRX through Fairwaves' fork of UHD
 * Red Pitaya SDR transceiver (http://bazaar.redpitaya.com)
+ * FreeSRP through libfreesrp

 By using the OsmoSDR block you can take advantage of a common software api in
 your application(s) independent of the underlying radio hardware.
--- a/cmake/Modules/FindLibFreeSRP.cmake
+++ b/cmake/Modules/FindLibFreeSRP.cmake
@ -0,0 +1,27 @@
+if(NOT LIBFREESRP_FOUND)
+  pkg_check_modules (LIBFREESRP_PKG libfreesrp)
+  find_path(LIBFREESRP_INCLUDE_DIRS NAMES freesrp.hpp
+    PATHS
+    ${LIBFREESRP_PKG_INCLUDE_DIRS}
+    /usr/include
+    /usr/local/include
+  )
+
+  find_library(LIBFREESRP_LIBRARIES NAMES freesrp
+    PATHS
+    ${LIBFREESRP_PKG_LIBRARY_DIRS}
+    /usr/lib
+    /usr/local/lib
+  )
+
+if(LIBFREESRP_INCLUDE_DIRS AND LIBFREESRP_LIBRARIES)
+  set(LIBFREESRP_FOUND TRUE CACHE INTERNAL "libfreesrp found")
+  message(STATUS "Found libfreesrp: ${LIBFREESRP_INCLUDE_DIRS}, ${LIBFREESRP_LIBRARIES}")
+else(LIBFREESRP_INCLUDE_DIRS AND LIBFREESRP_LIBRARIES)
+  set(LIBFREESRP_FOUND FALSE CACHE INTERNAL "libfreesrp found")
+  message(STATUS "libfreesrp not found.")
+endif(LIBFREESRP_INCLUDE_DIRS AND LIBFREESRP_LIBRARIES)
+
+mark_as_advanced(LIBFREESRP_LIBRARIES LIBFREESRP_INCLUDE_DIRS)
+
+endif(NOT LIBFREESRP_FOUND)
--- a/grc/gen_osmosdr_blocks.py
+++ b/grc/gen_osmosdr_blocks.py
@ -229,6 +229,7 @@ While primarily being developed for the OsmoSDR hardware, this block as well sup
 * Ettus USRP Devices through Ettus UHD library
 * Fairwaves UmTRX through Fairwaves' fork of UHD
 * Red Pitaya SDR transceiver (http://bazaar.redpitaya.com)
+ * FreeSRP through libfreesrp library

 By using the osmocom $sourk block you can take advantage of a common software api in your application(s) independent of the underlying radio hardware.

@ -264,6 +265,7 @@ Lines ending with ... mean it's possible to bind devices together by specifying
  file='/path/to/your file',rate=1e6[,freq=100e6][,append=true][,throttle=true] ...
 #end if
  redpitaya=192.168.1.100[:1001]
+  freesrp=0[,fx3='path/to/fx3.img',fpga='path/to/fpga.bin',loopback]
  hackrf=0[,buffers=32][,bias=0|1][,bias_tx=0|1]
  bladerf=0[,tamer=internal|external|external_1pps][,smb=25e6]
  uhd[,serial=...][,lo_offset=0][,mcr=52e6][,nchan=2][,subdev='\\\\'B:0 A:0\\\\''] ...
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@ -240,6 +240,14 @@ if(ENABLE_REDPITAYA)
 GR_INCLUDE_SUBDIRECTORY(redpitaya)
 endif(ENABLE_REDPITAYA)

+########################################################################
+# Setup FreeSRP component
+########################################################################
+GR_REGISTER_COMPONENT("FreeSRP support" ENABLE_FREESRP LIBFREESRP_FOUND)
+if(ENABLE_FREESRP)
+GR_INCLUDE_SUBDIRECTORY(freesrp)
+endif(ENABLE_FREESRP)
+
 ########################################################################
 # Setup configuration file
 ########################################################################
--- a/lib/config.h.in
+++ b/lib/config.h.in
@ -18,6 +18,7 @@
 #cmakedefine ENABLE_AIRSPY
 #cmakedefine ENABLE_SOAPY
 #cmakedefine ENABLE_REDPITAYA
+#cmakedefine ENABLE_FREESRP

 //provide NAN define for MSVC older than VC12
 #if defined(_MSC_VER) && (_MSC_VER < 1800)
--- a/lib/device.cc
+++ b/lib/device.cc
@ -86,6 +86,10 @@
 #include <redpitaya_source_c.h>
 #endif

+#ifdef ENABLE_FREESRP
+#include <freesrp_source_c.h>
+#endif
+
 #include "arg_helpers.h"

 using namespace osmosdr;
@ -182,6 +186,10 @@ devices_t device::find(const device_t &hint)
  BOOST_FOREACH( std::string dev, airspy_source_c::get_devices() )
    devices.push_back( device_t(dev) );
 #endif
+#ifdef ENABLE_FREESRP
+  BOOST_FOREACH( std::string dev, freesrp_source_c::get_devices() )
+    devices.push_back( device_t(dev) );
+#endif
 #ifdef ENABLE_SOAPY
  BOOST_FOREACH( std::string dev, soapy_source_c::get_devices() )
    devices.push_back( device_t(dev) );
--- a/lib/freesrp/CMakeLists.txt
+++ b/lib/freesrp/CMakeLists.txt
@ -0,0 +1,39 @@
+# Copyright 2012 Free Software Foundation, Inc.
+#
+# This file is part of GNU Radio
+#
+# GNU Radio 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, or (at your option)
+# any later version.
+#
+# GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+
+########################################################################
+# This file included, use CMake directory variables
+########################################################################
+
+include_directories(
+    ${CMAKE_CURRENT_SOURCE_DIR}
+    ${LIBFREESRP_INCLUDE_DIRS}
+)
+
+set(freesrp_srcs
+    ${CMAKE_CURRENT_SOURCE_DIR}/freesrp_common.cc
+    ${CMAKE_CURRENT_SOURCE_DIR}/freesrp_source_c.cc
+    ${CMAKE_CURRENT_SOURCE_DIR}/freesrp_sink_c.cc
+)
+
+########################################################################
+# Append gnuradio-osmosdr library sources
+########################################################################
+list(APPEND gr_osmosdr_srcs ${freesrp_srcs})
+list(APPEND gr_osmosdr_libs ${LIBFREESRP_LIBRARIES})
--- a/lib/freesrp/freesrp_common.cc
+++ b/lib/freesrp/freesrp_common.cc
@ -0,0 +1,199 @@
+#include "freesrp_common.h"
+
+#include <cstdlib>
+
+#include <boost/make_shared.hpp>
+#include <boost/assign.hpp>
+
+#include <arg_helpers.h>
+
+using namespace FreeSRP;
+using namespace std;
+using namespace boost::assign;
+
+boost::shared_ptr<::FreeSRP::FreeSRP> freesrp_common::_srp;
+
+freesrp_common::freesrp_common(const string &args)
+{
+    dict_t dict = params_to_dict(args);
+
+    if(!_srp)
+    {
+        try
+        {
+	    string serial = "";
+
+	    if(dict.count("freesrp"))
+	    {
+		serial = dict["freesrp"];
+	    }
+
+	    if(dict.count("fx3"))
+            {
+                if(Util::find_fx3())
+                {
+                    // Upload firmware to FX3
+                    string firmware_path = string(getenv("HOME")) + "/.freesrp/fx3.img";
+                    if(dict["fx3"].length() > 0)
+                    {
+                        firmware_path = dict["fx3"];
+                    }
+                    Util::find_fx3(true, firmware_path);
+                    cout << "FX3 programmed with '" << firmware_path << "'" << endl;
+                    // Give FX3 time to re-enumerate
+                    this_thread::sleep_for(chrono::milliseconds(600));
+                }
+                else
+                {
+                    cout << "No FX3 in bootloader mode found" << endl;
+                }
+            }
+
+            _srp.reset(new ::FreeSRP::FreeSRP(serial));
+
+            if(dict.count("fpga") || !_srp->fpga_loaded())
+            {
+                string bitstream_path = string(getenv("HOME")) + "/.freesrp/fpga.bin";
+                if(dict["fpga"].length() > 0)
+                {
+                    bitstream_path = dict["fpga"];
+                }
+                fpga_status stat = _srp->load_fpga(bitstream_path);
+                switch(stat)
+                {
+                case FPGA_CONFIG_ERROR:
+                    throw runtime_error("Could not load FPGA configuration!");
+                case FPGA_CONFIG_SKIPPED:
+                    cout << "FPGA already configured. Restart the FreeSRP to load a new bitstream." << endl;
+                    break;
+                case FPGA_CONFIG_DONE:
+                    cout << "FPGA configured with '" << bitstream_path << "'" << endl;
+                    break;
+                }
+            }
+
+            cout << "Connected to FreeSRP" << endl;
+
+            if(dict.count("loopback"))
+            {
+                response res = _srp->send_cmd({SET_LOOPBACK_EN, 1});
+                if(res.error == CMD_OK)
+                {
+                    cout << "AD9364 in loopback mode" << endl;
+                }
+                else
+                {
+                    throw runtime_error("Could not put AD9364 into loopback mode!");
+                }
+            }
+            else
+            {
+                response res = _srp->send_cmd({SET_LOOPBACK_EN, 0});
+                if(res.error != CMD_OK)
+                {
+                    throw runtime_error("Error disabling AD9364 loopback mode!");
+                }
+            }
+
+	    if(dict.count("ignore_overflow"))
+	    {
+		_ignore_overflow = true;
+	    }
+	    else
+	    {
+		_ignore_overflow = false;
+	    }
+        }
+        catch(const runtime_error& e)
+        {
+            cerr << "FreeSRP Error: " << e.what() << endl;
+            throw runtime_error(e.what());
+        }
+    }
+}
+
+vector<string> freesrp_common::get_devices()
+{
+    vector<string> devices;
+
+    try
+    {
+        ::FreeSRP::FreeSRP srp;
+
+        string str;
+        str = "freesrp=0,label='FreeSRP'";
+
+        devices.push_back(str);
+    }
+    catch(const ConnectionError &err)
+    {
+        // No FreeSRP found.
+    }
+
+    return devices;
+}
+
+size_t freesrp_common::get_num_channels( void )
+{
+    return 1;
+}
+
+osmosdr::meta_range_t freesrp_common::get_sample_rates( void )
+{
+    osmosdr::meta_range_t range;
+
+    // Any sample rate between 1e6 and 61.44e6 can be requested.
+    // This list of some integer values is used instead of
+    //       range += osmosdr::range_t(1e6, 61.44e6);
+    // because SoapyOsmo seems to handle the range object differently.
+    range += osmosdr::range_t(1e6);
+    range += osmosdr::range_t(8e6);
+    range += osmosdr::range_t(16e6);
+    range += osmosdr::range_t(20e6);
+    range += osmosdr::range_t(40e6);
+    range += osmosdr::range_t(50e6);
+    range += osmosdr::range_t(61.44e6);
+
+    return range;
+}
+
+osmosdr::freq_range_t freesrp_common::get_freq_range(size_t chan)
+{
+    osmosdr::meta_range_t freq_ranges;
+
+    freq_ranges.push_back(osmosdr::range_t(7e7, 6e9, 2.4));
+
+    return freq_ranges;
+}
+
+
+osmosdr::freq_range_t freesrp_common::get_bandwidth_range(size_t chan)
+{
+    osmosdr::meta_range_t range;
+
+    //range += osmosdr::range_t(2e5, 56e6);
+
+    range += osmosdr::range_t(2e5);
+    range += osmosdr::range_t(1e6);
+    range += osmosdr::range_t(8e6);
+    range += osmosdr::range_t(16e6);
+    range += osmosdr::range_t(20e6);
+    range += osmosdr::range_t(40e6);
+    range += osmosdr::range_t(50e6);
+    range += osmosdr::range_t(56e6);
+
+    return range;
+}
+
+
+double freesrp_common::set_freq_corr( double ppm, size_t chan )
+{
+    // TODO: Set DCXO tuning
+    return 0;
+}
+
+double freesrp_common::get_freq_corr( size_t chan )
+{
+    // TODO: Get DCXO tuning
+    return 0;
+}
--- a/lib/freesrp/freesrp_common.h
+++ b/lib/freesrp/freesrp_common.h
@ -0,0 +1,29 @@
+#ifndef INCLUDED_FREESRP_COMMON_H
+#define INCLUDED_FREESRP_COMMON_H
+
+#include <vector>
+#include <string>
+
+#include "osmosdr/ranges.h"
+
+#include <freesrp.hpp>
+
+class freesrp_common
+{
+protected:
+    freesrp_common(const std::string &args);
+public:
+    static std::vector<std::string> get_devices();
+
+    size_t get_num_channels( void );
+    osmosdr::meta_range_t get_sample_rates( void );
+    osmosdr::freq_range_t get_freq_range( size_t chan = 0 );
+    osmosdr::freq_range_t get_bandwidth_range( size_t chan = 0 );
+    double set_freq_corr( double ppm, size_t chan = 0 );
+    double get_freq_corr( size_t chan = 0 );
+protected:
+    static boost::shared_ptr<::FreeSRP::FreeSRP> _srp;
+    bool _ignore_overflow = false;
+};
+
+#endif
--- a/lib/freesrp/freesrp_sink_c.cc
+++ b/lib/freesrp/freesrp_sink_c.cc
@ -0,0 +1,280 @@
+#include "freesrp_sink_c.h"
+
+using namespace FreeSRP;
+using namespace std;
+
+freesrp_sink_c_sptr make_freesrp_sink_c (const string &args)
+{
+    return gnuradio::get_initial_sptr(new freesrp_sink_c (args));
+}
+
+/*
+ * Specify constraints on number of input and output streams.
+ * This info is used to construct the input and output signatures
+ * (2nd & 3rd args to gr_block's constructor).  The input and
+ * output signatures are used by the runtime system to
+ * check that a valid number and type of inputs and outputs
+ * are connected to this block.  In this case, we accept
+ * only 1 input and 0 output.
+ */
+static const int MIN_IN = 1;   // mininum number of input streams
+static const int MAX_IN = 1;   // maximum number of input streams
+static const int MIN_OUT = 0;  // minimum number of output streams
+static const int MAX_OUT = 0;  // maximum number of output streams
+
+freesrp_sink_c::freesrp_sink_c (const string & args) : gr::sync_block("freesrp_sink_c",
+                                                       gr::io_signature::make (MIN_IN, MAX_IN, sizeof (gr_complex)),
+                                                       gr::io_signature::make (MIN_OUT, MAX_OUT, sizeof (gr_complex))),
+                                                       freesrp_common(args)
+{
+    if(_srp == nullptr)
+    {
+        throw runtime_error("FreeSRP not initialized!");
+    }
+}
+
+bool freesrp_sink_c::start()
+{
+    response res = _srp->send_cmd({SET_DATAPATH_EN, 1});
+    if(res.error != CMD_OK)
+    {
+        return false;
+    }
+    _srp->start_tx(std::bind(&freesrp_sink_c::freesrp_tx_callback, this, std::placeholders::_1));
+    return true;
+}
+
+bool freesrp_sink_c::stop()
+{
+    _srp->send_cmd({SET_DATAPATH_EN, 0});
+    _srp->stop_tx();
+    return true;
+}
+
+void freesrp_sink_c::freesrp_tx_callback(vector<sample>& samples)
+{
+    unique_lock<std::mutex> lk(_buf_mut);
+
+    for(sample &s : samples)
+    {
+        if(!_buf_queue.try_dequeue(s))
+        {
+            s.i = 0;
+            s.q = 0;
+        }
+        else
+        {
+            _buf_available_space++;
+        }
+    }
+
+    _buf_cond.notify_one();
+}
+
+int freesrp_sink_c::work(int noutput_items, gr_vector_const_void_star& input_items, gr_vector_void_star& output_items)
+{
+    const gr_complex *in = (const gr_complex *) input_items[0];
+
+    unique_lock<std::mutex> lk(_buf_mut);
+
+    // Wait until enough space is available
+    while(_buf_available_space < (unsigned int) noutput_items)
+    {
+        _buf_cond.wait(lk);
+    }
+
+    for(int i = 0; i < noutput_items; ++i)
+    {
+        sample s;
+        s.i = (int16_t) (real(in[i]) * 2047.0f);
+        s.q = (int16_t) (imag(in[i]) * 2047.0f);
+
+        if(!_buf_queue.try_enqueue(s))
+        {
+            throw runtime_error("Failed to add sample to buffer. This should never happen. Available space reported to be " + to_string(_buf_available_space) + " samples, noutput_items=" + to_string(noutput_items) + ", i=" + to_string(i));
+        }
+        else
+        {
+            _buf_available_space--;
+        }
+    }
+
+    return noutput_items;
+}
+
+double freesrp_sink_c::set_sample_rate( double rate )
+{
+    command cmd = _srp->make_command(SET_TX_SAMP_FREQ, rate);
+    response r = _srp->send_cmd(cmd);
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not set TX sample rate, error: " << r.error << endl;
+        return 0;
+    }
+    else
+    {
+        return static_cast<double>(r.param);
+    }
+}
+
+double freesrp_sink_c::get_sample_rate( void )
+{
+    response r = _srp->send_cmd({GET_TX_SAMP_FREQ, 0});
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not get TX sample rate, error: " << r.error << endl;
+        return 0;
+    }
+    else
+    {
+        return r.param;
+    }
+}
+
+double freesrp_sink_c::set_center_freq( double freq, size_t chan )
+{
+    command cmd = _srp->make_command(SET_TX_LO_FREQ, freq);
+    response r = _srp->send_cmd(cmd);
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not set TX LO frequency, error: " << r.error << endl;
+        return 0;
+    }
+    else
+    {
+        return static_cast<double>(r.param);
+    }
+}
+
+double freesrp_sink_c::get_center_freq( size_t chan )
+{
+    response r = _srp->send_cmd({GET_TX_LO_FREQ, 0});
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not get TX LO frequency, error: " << r.error << endl;
+        return 0;
+    }
+    else
+    {
+        return static_cast<double>(r.param);
+    }
+}
+
+vector<string> freesrp_sink_c::get_gain_names( size_t chan )
+{
+    vector<string> names;
+
+    names.push_back("TX_RF");
+
+    return names;
+}
+
+osmosdr::gain_range_t freesrp_sink_c::get_gain_range(size_t chan)
+{
+    osmosdr::meta_range_t gain_ranges;
+
+    gain_ranges.push_back(osmosdr::range_t(0, 89.75, 0.25));
+
+    return gain_ranges;
+}
+
+osmosdr::gain_range_t freesrp_sink_c::get_gain_range(const string& name, size_t chan)
+{
+    return get_gain_range(chan);
+}
+
+double freesrp_sink_c::set_gain(double gain, size_t chan)
+{
+    gain = get_gain_range().clip(gain);
+
+    double atten = 89.75 - gain;
+
+    command cmd = _srp->make_command(SET_TX_ATTENUATION, atten * 1000);
+    response r = _srp->send_cmd(cmd);
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not set TX attenuation, error: " << r.error << endl;
+        return 0;
+    }
+    else
+    {
+        return 89.75 - (((double) r.param) / 1000.0);
+    }
+}
+
+double freesrp_sink_c::set_gain(double gain, const string& name, size_t chan)
+{
+    return set_gain(gain, chan);
+}
+
+double freesrp_sink_c::get_gain(size_t chan)
+{
+    response r = _srp->send_cmd({GET_TX_ATTENUATION, 0});
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not get TX RF attenuation, error: " << r.error << endl;
+        return 0;
+    }
+    else
+    {
+        return 89.75 - (((double) r.param) / 1000.0);
+    }
+}
+
+double freesrp_sink_c::get_gain(const string& name, size_t chan)
+{
+    return get_gain(chan);
+}
+
+double freesrp_sink_c::set_bb_gain(double gain, size_t chan)
+{
+    return set_gain(gain, chan);
+}
+
+vector<string> freesrp_sink_c::get_antennas(size_t chan)
+{
+    vector<string> antennas;
+
+    antennas.push_back(get_antenna(chan));
+
+    return antennas;
+}
+
+string freesrp_sink_c::set_antenna(const string& antenna, size_t chan)
+{
+    return get_antenna(chan);
+}
+
+string freesrp_sink_c::get_antenna(size_t chan)
+{
+    return "TX";
+}
+
+double freesrp_sink_c::set_bandwidth(double bandwidth, size_t chan)
+{
+    command cmd = _srp->make_command(SET_TX_RF_BANDWIDTH, bandwidth);
+    response r = _srp->send_cmd(cmd);
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not set TX RF bandwidth, error: " << r.error << endl;
+        return 0;
+    }
+    else
+    {
+        return static_cast<double>(r.param);
+    }
+}
+
+double freesrp_sink_c::get_bandwidth(size_t chan)
+{
+    response r = _srp->send_cmd({GET_TX_RF_BANDWIDTH, 0});
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not get TX RF bandwidth, error: " << r.error << endl;
+        return 0;
+    }
+    else
+    {
+        return r.param;
+    }
+}
--- a/lib/freesrp/freesrp_sink_c.h
+++ b/lib/freesrp/freesrp_sink_c.h
@ -0,0 +1,130 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2015 Lukas Lao Beyer
+ * Copyright 2013 Dimitri Stolnikov <horiz0n@gmx.net>
+ *
+ * GNU Radio 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, or (at your option)
+ * any later version.
+ *
+ * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+#ifndef INCLUDED_FREESRP_SINK_C_H
+#define INCLUDED_FREESRP_SINK_C_H
+
+#include <gnuradio/thread/thread.h>
+#include <gnuradio/block.h>
+#include <gnuradio/sync_block.h>
+
+#include "osmosdr/ranges.h"
+#include "sink_iface.h"
+
+#include "freesrp_common.h"
+#include "readerwriterqueue/readerwriterqueue.h"
+
+#include <mutex>
+#include <condition_variable>
+
+#include <freesrp.hpp>
+
+class freesrp_sink_c;
+
+/*
+ * We use boost::shared_ptr's instead of raw pointers for all access
+ * to gr_blocks (and many other data structures).  The shared_ptr gets
+ * us transparent reference counting, which greatly simplifies storage
+ * management issues.  This is especially helpful in our hybrid
+ * C++ / Python system.
+ *
+ * See http://www.boost.org/libs/smart_ptr/smart_ptr.htm
+ *
+ * As a convention, the _sptr suffix indicates a boost::shared_ptr
+ */
+typedef boost::shared_ptr<freesrp_sink_c> freesrp_sink_c_sptr;
+
+/*!
+ * \brief Return a shared_ptr to a new instance of freesrp_sink_c.
+ *
+ * To avoid accidental use of raw pointers, freesrp_sink_c's
+ * constructor is private.  make_freesrp_sink_c is the public
+ * interface for creating new instances.
+ */
+freesrp_sink_c_sptr make_freesrp_sink_c (const std::string & args = "");
+
+class freesrp_sink_c :
+    public gr::sync_block,
+    public sink_iface,
+    public freesrp_common
+{
+private:
+    // The friend declaration allows freesrp_make_sink_c to
+    // access the private constructor.
+    friend freesrp_sink_c_sptr make_freesrp_sink_c (const std::string & args);
+
+    freesrp_sink_c (const std::string & args);  	// private constructor
+
+public:
+
+    // From freesrp_common:
+    static std::vector<std::string> get_devices() { return freesrp_common::get_devices(); };
+    size_t get_num_channels( void ) { return freesrp_common::get_num_channels(); }
+    osmosdr::meta_range_t get_sample_rates( void ) { return freesrp_common::get_sample_rates(); }
+    osmosdr::freq_range_t get_freq_range( size_t chan = 0 ) { return freesrp_common::get_freq_range(chan); }
+    osmosdr::freq_range_t get_bandwidth_range( size_t chan = 0 ) { return freesrp_common::get_bandwidth_range(chan); }
+    double set_freq_corr( double ppm, size_t chan = 0 ) { return freesrp_common::set_freq_corr(ppm, chan); }
+    double get_freq_corr( size_t chan = 0 ) { return freesrp_common::get_freq_corr(chan); }
+
+    bool start();
+    bool stop();
+
+    int work( int noutput_items,
+              gr_vector_const_void_star &input_items,
+              gr_vector_void_star &output_items );
+
+    double set_sample_rate( double rate );
+    double get_sample_rate( void );
+
+    double set_center_freq( double freq, size_t chan = 0 );
+    double get_center_freq( size_t chan = 0 );
+
+    std::vector<std::string> get_gain_names( size_t chan = 0 );
+    osmosdr::gain_range_t get_gain_range( size_t chan = 0 );
+    osmosdr::gain_range_t get_gain_range( const std::string & name, size_t chan = 0 );
+    //TODO: implement this: bool set_gain_mode( bool automatic, size_t chan = 0 );
+    //TODO: implement this: bool get_gain_mode( size_t chan = 0 );
+    double set_gain( double gain, size_t chan = 0 );
+    double set_gain( double gain, const std::string & name, size_t chan = 0 );
+    double get_gain( size_t chan = 0 );
+    double get_gain( const std::string & name, size_t chan = 0 );
+
+    double set_bb_gain( double gain, size_t chan = 0 );
+
+    std::vector< std::string > get_antennas( size_t chan = 0 );
+    std::string set_antenna( const std::string & antenna, size_t chan = 0 );
+    std::string get_antenna( size_t chan = 0 );
+
+    double set_bandwidth( double bandwidth, size_t chan = 0 );
+    double get_bandwidth( size_t chan = 0 );
+
+private:
+
+    void freesrp_tx_callback(std::vector<::FreeSRP::sample> &samples);
+
+    bool _running = false;
+
+    std::mutex _buf_mut{};
+    std::condition_variable _buf_cond{};
+    size_t _buf_available_space = FREESRP_RX_TX_QUEUE_SIZE;
+    moodycamel::ReaderWriterQueue<::FreeSRP::sample> _buf_queue{FREESRP_RX_TX_QUEUE_SIZE};
+};
+
+#endif /* INCLUDED_FREESRP_SINK_C_H */
--- a/lib/freesrp/freesrp_source_c.cc
+++ b/lib/freesrp/freesrp_source_c.cc
@ -0,0 +1,341 @@
+#include "freesrp_source_c.h"
+
+using namespace FreeSRP;
+using namespace std;
+
+freesrp_source_c_sptr make_freesrp_source_c (const string &args)
+{
+    return gnuradio::get_initial_sptr(new freesrp_source_c (args));
+}
+
+/*
+ * Specify constraints on number of input and output streams.
+ * This info is used to construct the input and output signatures
+ * (2nd & 3rd args to gr_block's constructor).  The input and
+ * output signatures are used by the runtime system to
+ * check that a valid number and type of inputs and outputs
+ * are connected to this block.  In this case, we accept
+ * only 0 input and 1 output.
+ */
+static const int MIN_IN = 0;	// mininum number of input streams
+static const int MAX_IN = 0;	// maximum number of input streams
+static const int MIN_OUT = 1;	// minimum number of output streams
+static const int MAX_OUT = 1;	// maximum number of output streams
+
+freesrp_source_c::freesrp_source_c (const string & args) : gr::sync_block ("freesrp_source_c",
+                                                                gr::io_signature::make (MIN_IN, MAX_IN, sizeof (gr_complex)),
+                                                                gr::io_signature::make (MIN_OUT, MAX_OUT, sizeof (gr_complex))),
+                                                                freesrp_common(args)
+{
+    if(_srp == nullptr)
+    {
+        throw runtime_error("FreeSRP not initialized!");
+    }
+}
+
+bool freesrp_source_c::start()
+{
+    response res = _srp->send_cmd({SET_DATAPATH_EN, 1});
+    if(res.error != CMD_OK)
+    {
+        return false;
+    }
+    _srp->start_rx(std::bind(&freesrp_source_c::freesrp_rx_callback, this, std::placeholders::_1));
+
+    _running = true;
+
+    return true;
+}
+
+bool freesrp_source_c::stop()
+{
+    _srp->send_cmd({SET_DATAPATH_EN, 0});
+    _srp->stop_rx();
+
+    _running = false;
+
+    return true;
+}
+
+void freesrp_source_c::freesrp_rx_callback(const vector<sample> &samples)
+{
+    unique_lock<std::mutex> lk(_buf_mut);
+
+    for(const sample &s : samples)
+    {
+        if(!_buf_queue.try_enqueue(s))
+        {
+	    if(!_ignore_overflow)
+	    {
+		throw runtime_error("RX buffer overflow");
+	    }
+        }
+        else
+        {
+            _buf_num_samples++;
+        }
+    }
+
+    _buf_cond.notify_one();
+}
+
+int freesrp_source_c::work(int noutput_items, gr_vector_const_void_star& input_items, gr_vector_void_star& output_items)
+{
+    gr_complex *out = static_cast<gr_complex *>(output_items[0]);
+
+    unique_lock<std::mutex> lk(_buf_mut);
+
+    if(!_running)
+    {
+	return WORK_DONE;
+    }
+
+    // Wait until enough samples collected
+    while(_buf_num_samples < (unsigned int) noutput_items)
+    {
+        _buf_cond.wait(lk);
+    }
+
+    for(int i = 0; i < noutput_items; ++i)
+    {
+        sample s;
+        if(!_buf_queue.try_dequeue(s))
+        {
+            // This should not be happening
+            throw runtime_error("Failed to get sample from buffer. This should never happen. Number of available samples reported to be " + to_string(_buf_num_samples) + ", noutput_items=" + to_string(noutput_items) + ", i=" + to_string(i));
+        }
+        else
+        {
+            _buf_num_samples--;
+        }
+
+        out[i] = gr_complex(((float) s.i) / 2048.0f, ((float) s.q) / 2048.0f);
+    }
+
+    return noutput_items;
+}
+
+double freesrp_source_c::set_sample_rate( double rate )
+{
+    command cmd = _srp->make_command(SET_RX_SAMP_FREQ, rate);
+    response r = _srp->send_cmd(cmd);
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not set RX sample rate, error: " << r.error << endl;
+        return 0;
+    }
+    else
+    {
+        return static_cast<double>(r.param);
+    }
+}
+
+double freesrp_source_c::get_sample_rate( void )
+{
+    response r = _srp->send_cmd({GET_RX_SAMP_FREQ, 0});
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not get RX sample rate, error: " << r.error << endl;
+        return 0;
+    }
+    else
+    {
+        return static_cast<double>(r.param);
+    }
+}
+
+double freesrp_source_c::set_center_freq( double freq, size_t chan )
+{
+    command cmd = _srp->make_command(SET_RX_LO_FREQ, freq);
+    response r = _srp->send_cmd(cmd);
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not set RX LO frequency, error: " << r.error << endl;
+        return 0;
+    }
+    else
+    {
+        return static_cast<double>(r.param);
+    }
+}
+
+double freesrp_source_c::get_center_freq( size_t chan )
+{
+    response r = _srp->send_cmd({GET_RX_LO_FREQ, 0});
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not get RX LO frequency, error: " << r.error << endl;
+        return 0;
+    }
+    else
+    {
+        return static_cast<double>(r.param);
+    }
+}
+
+vector<string> freesrp_source_c::get_gain_names( size_t chan )
+{
+    vector<string> names;
+
+    names.push_back("RF");
+
+    return names;
+}
+
+osmosdr::gain_range_t freesrp_source_c::get_gain_range(size_t chan)
+{
+    osmosdr::meta_range_t gain_ranges;
+
+    gain_ranges.push_back(osmosdr::range_t(0, 74, 1));
+
+    return gain_ranges;
+}
+
+bool freesrp_source_c::set_gain_mode( bool automatic, size_t chan )
+{
+    uint8_t gc_mode = RF_GAIN_SLOWATTACK_AGC;
+
+    if(!automatic)
+    {
+        gc_mode = RF_GAIN_MGC;
+    }
+
+    command cmd = _srp->make_command(SET_RX_GC_MODE, gc_mode);
+    response r = _srp->send_cmd(cmd);
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not set RX RF gain control mode, error: " << r.error << endl;
+        return false;
+    }
+    else
+    {
+        return r.param != RF_GAIN_MGC;
+    }
+}
+
+bool freesrp_source_c::get_gain_mode( size_t chan )
+{
+    response r = _srp->send_cmd({GET_RX_GC_MODE, 0});
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not get RX RF gain control mode, error: " << r.error << endl;
+        return false;
+    }
+    else
+    {
+        return r.param != RF_GAIN_MGC;
+    }
+}
+
+osmosdr::gain_range_t freesrp_source_c::get_gain_range(const string& name, size_t chan)
+{
+    return get_gain_range(chan);
+}
+
+double freesrp_source_c::set_gain(double gain, size_t chan)
+{
+    gain = get_gain_range().clip(gain);
+
+    command cmd = _srp->make_command(SET_RX_RF_GAIN, gain);
+    response r = _srp->send_cmd(cmd);
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not set RX RF gain, error: " << r.error << endl;
+        return 0;
+    }
+    else
+    {
+        return r.param;
+    }
+}
+
+double freesrp_source_c::set_gain(double gain, const string& name, size_t chan)
+{
+    if(name == "RF")
+    {
+        return set_gain(gain, chan);
+    }
+    else
+    {
+        return 0;
+    }
+}
+
+double freesrp_source_c::get_gain(size_t chan)
+{
+    response r = _srp->send_cmd({GET_RX_RF_GAIN, 0});
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not get RX RF gain, error: " << r.error << endl;
+        return 0;
+    }
+    else
+    {
+        return (static_cast<double>(r.param));
+    }
+}
+
+double freesrp_source_c::get_gain(const string& name, size_t chan)
+{
+    if(name == "RF")
+    {
+        return get_gain(chan);
+    }
+    else
+    {
+        return 0;
+    }
+}
+
+double freesrp_source_c::set_bb_gain(double gain, size_t chan)
+{
+    return set_gain(gain, chan);
+}
+
+vector<string> freesrp_source_c::get_antennas(size_t chan)
+{
+    vector<string> antennas;
+
+    antennas.push_back(get_antenna(chan));
+
+    return antennas;
+}
+
+string freesrp_source_c::set_antenna(const string& antenna, size_t chan)
+{
+    return get_antenna(chan);
+}
+
+string freesrp_source_c::get_antenna(size_t chan)
+{
+    return "RX";
+}
+
+double freesrp_source_c::set_bandwidth(double bandwidth, size_t chan)
+{
+    command cmd = _srp->make_command(SET_RX_RF_BANDWIDTH, bandwidth);
+    response r = _srp->send_cmd(cmd);
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not set RX RF bandwidth, error: " << r.error << endl;
+        return 0;
+    }
+    else
+    {
+        return static_cast<double>(r.param);
+    }
+}
+
+double freesrp_source_c::get_bandwidth(size_t chan)
+{
+    response r = _srp->send_cmd({GET_RX_RF_BANDWIDTH, 0});
+    if(r.error != CMD_OK)
+    {
+        cerr << "Could not get RX RF bandwidth, error: " << r.error << endl;
+        return 0;
+    }
+    else
+    {
+        return static_cast<double>(r.param);
+    }
+}
--- a/lib/freesrp/freesrp_source_c.h
+++ b/lib/freesrp/freesrp_source_c.h
@ -0,0 +1,131 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2015 Lukas Lao Beyer
+ * Copyright 2013 Dimitri Stolnikov <horiz0n@gmx.net>
+ *
+ * GNU Radio 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, or (at your option)
+ * any later version.
+ *
+ * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+#ifndef INCLUDED_FREESRP_SOURCE_C_H
+#define INCLUDED_FREESRP_SOURCE_C_H
+
+#include <gnuradio/thread/thread.h>
+#include <gnuradio/block.h>
+#include <gnuradio/sync_block.h>
+
+#include "osmosdr/ranges.h"
+#include "source_iface.h"
+
+#include "freesrp_common.h"
+
+#include "readerwriterqueue/readerwriterqueue.h"
+
+#include <freesrp.hpp>
+
+#include <mutex>
+#include <condition_variable>
+
+class freesrp_source_c;
+
+/*
+ * We use boost::shared_ptr's instead of raw pointers for all access
+ * to gr_blocks (and many other data structures).  The shared_ptr gets
+ * us transparent reference counting, which greatly simplifies storage
+ * management issues.  This is especially helpful in our hybrid
+ * C++ / Python system.
+ *
+ * See http://www.boost.org/libs/smart_ptr/smart_ptr.htm
+ *
+ * As a convention, the _sptr suffix indicates a boost::shared_ptr
+ */
+typedef boost::shared_ptr<freesrp_source_c> freesrp_source_c_sptr;
+
+/*!
+ * \brief Return a shared_ptr to a new instance of freesrp_source_c.
+ *
+ * To avoid accidental use of raw pointers, freesrp_source_c's
+ * constructor is private.  freesrp_make_source_c is the public
+ * interface for creating new instances.
+ */
+freesrp_source_c_sptr make_freesrp_source_c (const std::string & args = "");
+
+class freesrp_source_c :
+    public gr::sync_block,
+    public source_iface,
+    public freesrp_common
+{
+private:
+    // The friend declaration allows freesrp_make_source_c to
+    // access the private constructor.
+    friend freesrp_source_c_sptr make_freesrp_source_c (const std::string & args);
+
+    freesrp_source_c (const std::string & args);  	// private constructor
+
+public:
+
+    // From freesrp_common:
+    static std::vector<std::string> get_devices() { return freesrp_common::get_devices(); };
+    size_t get_num_channels( void ) { return freesrp_common::get_num_channels(); }
+    osmosdr::meta_range_t get_sample_rates( void ) { return freesrp_common::get_sample_rates(); }
+    osmosdr::freq_range_t get_freq_range( size_t chan = 0 ) { return freesrp_common::get_freq_range(chan); }
+    osmosdr::freq_range_t get_bandwidth_range( size_t chan = 0 ) { return freesrp_common::get_bandwidth_range(chan); }
+    double set_freq_corr( double ppm, size_t chan = 0 ) { return freesrp_common::set_freq_corr(ppm, chan); }
+    double get_freq_corr( size_t chan = 0 ) { return freesrp_common::get_freq_corr(chan); }
+
+    bool start();
+    bool stop();
+
+    int work( int noutput_items,
+            gr_vector_const_void_star &input_items,
+            gr_vector_void_star &output_items );
+
+    double set_sample_rate( double rate );
+    double get_sample_rate( void );
+
+    double set_center_freq( double freq, size_t chan = 0 );
+    double get_center_freq( size_t chan = 0 );
+
+    std::vector<std::string> get_gain_names( size_t chan = 0 );
+    osmosdr::gain_range_t get_gain_range( size_t chan = 0 );
+    osmosdr::gain_range_t get_gain_range( const std::string & name, size_t chan = 0 );
+    bool set_gain_mode( bool automatic, size_t chan = 0 );
+    bool get_gain_mode( size_t chan = 0 );
+    double set_gain( double gain, size_t chan = 0 );
+    double set_gain( double gain, const std::string & name, size_t chan = 0 );
+    double get_gain( size_t chan = 0 );
+    double get_gain( const std::string & name, size_t chan = 0 );
+
+    double set_bb_gain( double gain, size_t chan = 0 );
+
+    std::vector< std::string > get_antennas( size_t chan = 0 );
+    std::string set_antenna( const std::string & antenna, size_t chan = 0 );
+    std::string get_antenna( size_t chan = 0 );
+
+    double set_bandwidth( double bandwidth, size_t chan = 0 );
+    double get_bandwidth( size_t chan = 0 );
+
+private:
+
+    void freesrp_rx_callback(const std::vector<FreeSRP::sample> &samples);
+
+    bool _running = false;
+
+    std::mutex _buf_mut{};
+    std::condition_variable _buf_cond{};
+    size_t _buf_num_samples = 0;
+    moodycamel::ReaderWriterQueue<FreeSRP::sample> _buf_queue{FREESRP_RX_TX_QUEUE_SIZE};
+};
+
+#endif /* INCLUDED_FREESRP_SOURCE_C_H */
--- a/lib/freesrp/readerwriterqueue/LICENSE.md
+++ b/lib/freesrp/readerwriterqueue/LICENSE.md
@ -0,0 +1,28 @@
+This license applies to all the code in this repository except that written by third
+parties, namely the files in benchmarks/ext, which have their own licenses, and Jeff
+Preshing's semaphore implementation (used in the blocking queue) which has a zlib
+license (embedded in atomicops.h).
+
+Simplified BSD License:
+
+Copyright (c) 2013-2015, Cameron Desrochers  
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+- Redistributions of source code must retain the above copyright notice, this list of
+conditions and the following disclaimer.
+- Redistributions in binary form must reproduce the above copyright notice, this list of
+conditions and the following disclaimer in the documentation and/or other materials
+provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
+TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
--- a/lib/freesrp/readerwriterqueue/README.md
+++ b/lib/freesrp/readerwriterqueue/README.md
@ -0,0 +1,114 @@
+# A single-producer, single-consumer lock-free queue for C++
+
+This mini-repository has my very own implementation of a lock-free queue (that I designed from scratch) for C++.
+
+It only supports a two-thread use case (one consuming, and one producing). The threads can't switch roles, though
+you could use this queue completely from a single thread if you wish (but that would sort of defeat the purpose!).
+
+Note: If you need a general purpse multi-producer, multi-consumer lock free queue, I have [one of those too][mpmc].
+
+
+## Features
+
+- [Blazing fast][benchmarks]
+- Compatible with C++11 (supports moving objects instead of making copies)
+- Fully generic (templated container of any type) -- just like `std::queue`, you never need to allocate memory for elements yourself
+  (which saves you the hassle of writing a lock-free memory manager to hold the elements you're queueing)
+- Allocates memory up front, in contiguous blocks
+- Provides a `try_enqueue` method which is guaranteed never to allocate memory (the queue starts with an initial capacity)
+- Also provides an `enqueue` method which can dynamically grow the size of the queue as needed
+- Also provides a blocking version with `wait_dequeue`
+- Completely "wait-free" (no compare-and-swap loop). Enqueue and dequeue are always O(1) (not counting memory allocation)
+- On x86, the memory barriers compile down to no-ops, meaning enqueue and dequeue are just a simple series of loads and stores (and branches)
+
+
+## Use
+
+Simply drop the readerwriterqueue.h and atomicops.h files into your source code and include them :-)
+A modern compiler is required (MSVC2010+, GCC 4.7+, ICC 13+, or any C++11 compliant compiler should work).
+
+Note: If you're using GCC, you really do need GCC 4.7 or above -- [4.6 has a bug][gcc46bug] that prevents the atomic fence primitives
+from working correctly.
+
+Example:
+
+```cpp
+using namespace moodycamel;
+
+ReaderWriterQueue<int> q(100);       // Reserve space for at least 100 elements up front
+
+q.enqueue(17);                       // Will allocate memory if the queue is full
+bool succeeded = q.try_enqueue(18);  // Will only succeed if the queue has an empty slot (never allocates)
+assert(succeeded);
+
+int number;
+succeeded = q.try_dequeue(number);  // Returns false if the queue was empty
+
+assert(succeeded && number == 17);
+
+// You can also peek at the front item of the queue (consumer only)
+int* front = q.peek();
+assert(*front == 18);
+succeeded = q.try_dequeue(number);
+assert(succeeded && number == 18);
+front = q.peek(); 
+assert(front == nullptr);           // Returns nullptr if the queue was empty
+```
+
+The blocking version has the exact same API, with the addition of a `wait_dequeue` method:
+
+```cpp
+BlockingReaderWriterQueue<int> q;
+
+std::thread reader([&]() {
+    int item;
+    for (int i = 0; i != 100; ++i) {
+        q.wait_dequeue(item);
+    }
+});
+std::thread writer([&]() {
+    for (int i = 0; i != 100; ++i) {
+        q.enqueue(i);
+    }
+});
+writer.join();
+reader.join();
+
+assert(q.size_approx() == 0);
+```
+    
+Note that `wait_dequeue` will block indefinitely while the queue is empty; this
+means care must be taken to only call `wait_dequeue` if you're sure another element
+will come along eventually, or if the queue has a static lifetime. This is because
+destroying the queue while a thread is waiting on it will invoke undefined behaviour.
+
+    
+## Disclaimers
+
+The queue should only be used on platforms where aligned integer and pointer access is atomic; fortunately, that
+includes all modern processors (e.g. x86/x86-64, ARM, and PowerPC). *Not* for use with a DEC Alpha processor (which has very weak memory ordering) :-)
+
+Note that it's only been tested on x86(-64); if someone has access to other processors I'd love to run some tests on
+anything that's not x86-based.
+
+Finally, I am not an expert. This is my first foray into lock-free programming, and though I'm confident in the code,
+it's possible that there are bugs despite the effort I put into designing and testing this data structure.
+
+Use this code at your own risk; in particular, lock-free programming is a patent minefield, and this code may very
+well violate a pending patent (I haven't looked). It's worth noting that I came up with this algorithm and
+implementation from scratch, independent of any existing lock-free queues.
+
+
+## More info
+
+See the [LICENSE.md][license] file for the license (simplified BSD).
+
+My [blog post][blog] introduces the context that led to this code, and may be of interest if you're curious
+about lock-free programming.
+
+
+[blog]: http://moodycamel.com/blog/2013/a-fast-lock-free-queue-for-c++
+[license]: LICENSE.md
+[benchmarks]: http://moodycamel.com/blog/2013/a-fast-lock-free-queue-for-c++#benchmarks
+[gcc46bug]: http://stackoverflow.com/questions/16429669/stdatomic-thread-fence-has-undefined-reference
+[mpmc]: https://github.com/cameron314/concurrentqueue
--- a/lib/freesrp/readerwriterqueue/atomicops.h
+++ b/lib/freesrp/readerwriterqueue/atomicops.h
@ -0,0 +1,577 @@
+// ©2013-2015 Cameron Desrochers.
+// Distributed under the simplified BSD license (see the license file that
+// should have come with this header).
+// Uses Jeff Preshing's semaphore implementation (under the terms of its