From c78d307ecd5dac4e28190e5aa9b8377538f65ffa Mon Sep 17 00:00:00 2001
From: Josh Blum
Date: Thu, 24 May 2012 11:34:12 -0700
Subject: uhd: allow source work to be stopped while fg runs

---
 gr-uhd/lib/gr_uhd_usrp_source.cc | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

(limited to 'gr-uhd/lib/gr_uhd_usrp_source.cc')

diff --git a/gr-uhd/lib/gr_uhd_usrp_source.cc b/gr-uhd/lib/gr_uhd_usrp_source.cc
index 8aa965401..99deb70c7 100644
--- a/gr-uhd/lib/gr_uhd_usrp_source.cc
+++ b/gr-uhd/lib/gr_uhd_usrp_source.cc
@@ -24,6 +24,8 @@
 #include <stdexcept>
 #include <iostream>
 #include <boost/format.hpp>
+#include <boost/thread/mutex.hpp>
+#include <boost/thread/condition_variable.hpp>
 #include <boost/make_shared.hpp>
 #include "gr_uhd_common.h"
 
@@ -60,7 +62,8 @@ public:
         _nchan(std::max<size_t>(1, stream_args.channels.size())),
         _stream_now(_nchan == 1),
         _tag_now(false),
-        _start_time_set(false)
+        _start_time_set(false),
+        _is_streaming(false)
     {
         if (stream_args.cpu_format == "fc32") _type = boost::make_shared<uhd::io_type_t>(uhd::io_type_t::COMPLEX_FLOAT32);
         if (stream_args.cpu_format == "sc16") _type = boost::make_shared<uhd::io_type_t>(uhd::io_type_t::COMPLEX_INT16);
@@ -320,6 +323,13 @@ public:
         gr_vector_const_void_star &input_items,
         gr_vector_void_star &output_items
     ){
+        boost::mutex::scoped_lock lock(_mutex);
+
+        while (!_is_streaming)
+        {
+            _cond.wait(lock);
+        }
+
         #ifdef GR_UHD_USE_STREAM_API
         //In order to allow for low-latency:
         //We receive all available packets without timeout.
@@ -392,6 +402,9 @@ public:
     }
 
     bool start(void){
+        boost::mutex::scoped_lock lock(_mutex);
+        _is_streaming = true;
+
         #ifdef GR_UHD_USE_STREAM_API
         _rx_stream = _dev->get_rx_stream(_stream_args);
         _samps_per_packet = _rx_stream->get_max_num_samps();
@@ -436,6 +449,9 @@ public:
     }
 
     bool stop(void){
+        boost::mutex::scoped_lock lock(_mutex);
+        _is_streaming = false;
+
         _dev->issue_stream_cmd(uhd::stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS);
 
         this->flush();
@@ -508,6 +524,10 @@ private:
 
     uhd::time_spec_t _start_time;
     bool _start_time_set;
+
+    bool _is_streaming;
+    boost::condition_variable _cond;
+    boost::mutex _mutex;
 };
 
 
-- 
cgit