4 files changed, 49 insertions, 2 deletions
diff --git a/gr-blocks/lib/stream_to_tagged_stream_impl.cc b/gr-blocks/lib/stream_to_tagged_stream_impl.cc
index 58e1a9c5b0..f0de33a16f 100644
--- a/gr-blocks/lib/stream_to_tagged_stream_impl.cc
+++ b/gr-blocks/lib/stream_to_tagged_stream_impl.cc
@@ -84,6 +84,13 @@ namespace gr {
         return noutput_items;
     }
 
+    bool
+    stream_to_tagged_stream_impl::start()
+    {
+        d_next_tag_pos = 0;
+        return true;
+    }
+
   } /* namespace blocks */
 } /* namespace gr */
 
diff --git a/gr-blocks/lib/stream_to_tagged_stream_impl.h b/gr-blocks/lib/stream_to_tagged_stream_impl.h
index dc9c117765..586bd202fa 100644
--- a/gr-blocks/lib/stream_to_tagged_stream_impl.h
+++ b/gr-blocks/lib/stream_to_tagged_stream_impl.h
@@ -46,6 +46,8 @@ namespace gr {
       int work(int noutput_items,
 	       gr_vector_const_void_star &input_items,
 	       gr_vector_void_star &output_items);
+
+      bool start();
     };
 
   } // namespace blocks
diff --git a/gr-fft/lib/fft.cc b/gr-fft/lib/fft.cc
index 5af77d97eb..ef81583187 100644
--- a/gr-fft/lib/fft.cc
+++ b/gr-fft/lib/fft.cc
@@ -46,10 +46,12 @@ static int my_fftw_read_char(void *f) { return fgetc((FILE *) f); }
 
 #include <boost/filesystem/operations.hpp>
 #include <boost/filesystem/path.hpp>
+#include <boost/interprocess/sync/file_lock.hpp>
 namespace fs = boost::filesystem;
 
 namespace gr {
   namespace fft {
+    static boost::mutex wisdom_thread_mutex;
 
     gr_complex *
     malloc_complex(int size)
@@ -92,6 +94,30 @@ namespace gr {
     }
 
     static void
+    lock_wisdom()
+    {
+      const std::string wisdom_lock_file = wisdom_filename() + ".lock";
+      int fd = open(wisdom_lock_file.c_str(),
+                    O_WRONLY|O_CREAT|O_NOCTTY|O_NONBLOCK,
+                    0666);
+      if (fd < 0){
+        throw std::exception();
+      }
+      boost::interprocess::file_lock wisdom_lock(wisdom_lock_file.c_str());
+      wisdom_lock.lock();
+      wisdom_thread_mutex.lock();
+    }
+
+    static void
+    unlock_wisdom()
+    {
+      const std::string wisdom_lock_file = wisdom_filename() + ".lock";
+      boost::interprocess::file_lock wisdom_lock(wisdom_lock_file.c_str());
+      wisdom_lock.unlock();
+      wisdom_thread_mutex.unlock();
+    }
+
+    static void
     import_wisdom()
     {
       const std::string filename = wisdom_filename ();
@@ -162,6 +188,7 @@ namespace gr {
 
       d_nthreads = nthreads;
       config_threading(nthreads);
+      lock_wisdom();
       import_wisdom();	// load prior wisdom from disk
 
       d_plan = fftwf_plan_dft_1d (fft_size,
@@ -175,6 +202,7 @@ namespace gr {
         throw std::runtime_error ("fftwf_plan_dft_1d failed");
       }
       export_wisdom();	// store new wisdom to disk
+      unlock_wisdom();
     }
 
     fft_complex::~fft_complex()
@@ -233,6 +261,7 @@ namespace gr {
 
       d_nthreads = nthreads;
       config_threading(nthreads);
+      lock_wisdom();
       import_wisdom();	// load prior wisdom from disk
 
       d_plan = fftwf_plan_dft_r2c_1d (fft_size,
@@ -245,6 +274,7 @@ namespace gr {
         throw std::runtime_error ("fftwf_plan_dft_r2c_1d failed");
       }
       export_wisdom();	// store new wisdom to disk
+      unlock_wisdom();
     }
 
     fft_real_fwd::~fft_real_fwd()
@@ -303,6 +333,7 @@ namespace gr {
 
       d_nthreads = nthreads;
       config_threading(nthreads);
+      lock_wisdom();
       import_wisdom();	// load prior wisdom from disk
 
       // FIXME If there's ever a chance that the planning functions
@@ -318,6 +349,7 @@ namespace gr {
         throw std::runtime_error ("fftwf_plan_dft_c2r_1d failed");
       }
       export_wisdom ();	// store new wisdom to disk
+      unlock_wisdom();
     }
 
     fft_real_rev::~fft_real_rev ()
diff --git a/gr-uhd/apps/uhd_fft b/gr-uhd/apps/uhd_fft
index 1f0cf1cda5..4cb5eed0d1 100755
--- a/gr-uhd/apps/uhd_fft
+++ b/gr-uhd/apps/uhd_fft
@@ -140,9 +140,15 @@ class uhd_fft(gr.top_block, Qt.QWidget, UHDApp):
         self._samp_rate__tool_bar.addWidget(self._samp_rate__line_edit)
         self._samp_rate__line_edit.returnPressed.connect(
             lambda: self.set_samp_rate(eng_notation.str_to_num(str(self._samp_rate__line_edit.text().toAscii()))))
-        self.top_grid_layout.addWidget(self._samp_rate__tool_bar, 3,2,1,2)
+        self.top_grid_layout.addWidget(self._samp_rate__tool_bar, 3, 2, 1, 2)
         # Gain:
-        self._gain__range = Range(self.gain_range.start(), self.gain_range.stop(), self.gain_range.step(), self.gain, 200)
+        self._gain__range = Range(
+            self.gain_range.start(),
+            self.gain_range.stop(),
+            max(self.gain_range.step(), 1.0),
+            self.gain,
+            200
+        )
         self._gain__win = RangeWidget(self._gain__range, self.set_gain, "RX Gain", "counter_slider", float)
         self.top_grid_layout.addWidget(self._gain__win, 2,0,1,4)
         # Center frequency: