reset gr buffer counters

gistfile1.txt

diff --git a/gnuradio-runtime/include/gnuradio/block_detail.h b/gnuradio-runtime/include/gnuradio/block_detail.h
index 41568c8..8f9b039 100644
--- a/gnuradio-runtime/include/gnuradio/block_detail.h
+++ b/gnuradio-runtime/include/gnuradio/block_detail.h
@@ -94,13 +94,25 @@ namespace gr {
      */
     void produce_each(int how_many_items);
 
-    // Return the number of items read on input stream which_input
+    /*!
+     *  Return the number of items read on input stream \p which_input.
+     */
     uint64_t nitems_read(unsigned int which_input);
 
-    // Return the number of items written on output stream which_output
+    /*!
+     *  Return the number of items written on output stream
+     *  \p which_output.
+     */
     uint64_t nitems_written(unsigned int which_output);
 
     /*!
+     *  Resets all read and write counters for all the block's
+     *  buffers. Mostly meant to be called during a flowgraph
+     *  reconfiguration.
+     */
+    void reset_buffer_counters();
+
+    /*!
      * \brief  Adds a new tag to the given output stream.
      *
      * Calls gr::buffer::add_item_tag(),
diff --git a/gnuradio-runtime/include/gnuradio/buffer.h b/gnuradio-runtime/include/gnuradio/buffer.h
index c0c9f3d..5b24901 100644
--- a/gnuradio-runtime/include/gnuradio/buffer.h
+++ b/gnuradio-runtime/include/gnuradio/buffer.h
@@ -93,8 +93,18 @@ namespace gr {
 
     gr::thread::mutex *mutex() { return &d_mutex; }
 
+    /*!
+     *  Returns a counter of the number of items written to this
+     *  buffer since the start/restart of a flowgraph.
+     */
     uint64_t nitems_written() { return d_abs_write_offset; }
 
+    /*!
+     *  Resets the buffer's write counter. Immediately after this call,
+     *  nitems_written will return 0.
+     */
+    void reset_nitems_written() { d_abs_write_offset = 0; }
+
     size_t get_sizeof_item() { return d_sizeof_item; }
 
     /*!
@@ -281,8 +291,18 @@ namespace gr {
 
     gr::thread::mutex *mutex() { return d_buffer->mutex(); }
 
+    /*!
+     *  Returns a counter of the number of items read by this buffer
+     *  reader since the start/restart of a flowgraph.
+     */
     uint64_t nitems_read() { return d_abs_read_offset; }
 
+    /*!
+     *  Resets the buffer's read counter. Immediately after this call,
+     *  nitems_read will return 0.
+     */
+    void reset_nitems_read() { d_abs_read_offset = 0; }
+
     size_t get_sizeof_item() { return d_buffer->get_sizeof_item(); }
 
     /*!
diff --git a/gnuradio-runtime/lib/block_detail.cc b/gnuradio-runtime/lib/block_detail.cc
index 77c457c..bfa14ca 100644
--- a/gnuradio-runtime/lib/block_detail.cc
+++ b/gnuradio-runtime/lib/block_detail.cc
@@ -159,6 +159,17 @@ namespace gr {
   }
 
   void
+  block_detail::reset_buffer_counters()
+  {
+    for(unsigned int n = 0; n < d_ninputs; n++) {
+      d_input[n]->reset_nitems_read();
+    }
+    for(unsigned int n = 0; n < d_noutputs; n++) {
+      d_output[n]->reset_nitems_written();
+    }
+  }
+
+  void
   block_detail::add_item_tag(unsigned int which_output, const tag_t &tag)
   {
     if(!pmt::is_symbol(tag.key)) {
diff --git a/gnuradio-runtime/lib/flat_flowgraph.cc b/gnuradio-runtime/lib/flat_flowgraph.cc
index 9e5964c..36fe0bb 100644
--- a/gnuradio-runtime/lib/flat_flowgraph.cc
+++ b/gnuradio-runtime/lib/flat_flowgraph.cc
@@ -304,6 +304,9 @@ namespace gr {
       // Now deal with the fact that the block details might have
       // changed numbers of inputs and outputs vs. in the old
       // flowgraph.
+
+      // Makes sure all buffer counters are reset for each block.
+      block->detail()->reset_buffer_counters();
     }
   }