2 files changed, 13 insertions, 10 deletions
diff --git a/gnuradio-runtime/include/gnuradio/block.h b/gnuradio-runtime/include/gnuradio/block.h
index 473b94c155..eac8845448 100644
--- a/gnuradio-runtime/include/gnuradio/block.h
+++ b/gnuradio-runtime/include/gnuradio/block.h
@@ -684,6 +684,8 @@ namespace gr {
     bool                  d_update_rate;           // should sched update rel rate?
     bool d_finished;    // true if msg ports think we are finished
 
+    static const pmt::pmt_t d_pmt_done;
+
   protected:
     block(void) {} // allows pure virtual interface sub-classes
     block(const std::string &name,
@@ -861,6 +863,10 @@ namespace gr {
     // These are really only for internal use, but leaving them public avoids
     // having to work up an ever-varying list of friend GR_RUNTIME_APIs
 
+    /*! PMT Symbol of the system port, `pmt::mp("system")`
+     */
+    static const pmt::pmt_t d_system_port;
+
   public:
     block_detail_sptr detail() const { return d_detail; }
     void set_detail(block_detail_sptr detail) { d_detail = detail; }
diff --git a/gnuradio-runtime/lib/block.cc b/gnuradio-runtime/lib/block.cc
index 2bae8ea9f8..c7eafb0fc7 100644
--- a/gnuradio-runtime/lib/block.cc
+++ b/gnuradio-runtime/lib/block.cc
@@ -34,6 +34,9 @@
 
 namespace gr {
 
+  const pmt::pmt_t block::d_system_port = pmt::intern("system");
+  const pmt::pmt_t block::d_pmt_done = pmt::intern("done");
+
   block::block(const std::string &name,
                io_signature::sptr input_signature,
                io_signature::sptr output_signature)
@@ -57,8 +60,8 @@ namespace gr {
       d_min_output_buffer(std::max(output_signature->max_streams(),1), -1)
   {
     global_block_registry.register_primitive(alias(), this);
-    message_port_register_in(pmt::mp("system"));
-    set_msg_handler(pmt::mp("system"), boost::bind(&block::system_handler, this, _1));
+    message_port_register_in(d_system_port);
+    set_msg_handler(d_system_port, boost::bind(&block::system_handler, this, _1));
 
     configure_default_loggers(d_logger, d_debug_logger, symbol_name());
   }
@@ -706,7 +709,7 @@ namespace gr {
   {
     //std::cout << "system_handler " << msg << "\n";
     pmt::pmt_t op = pmt::car(msg);
-    if(pmt::eqv(op, pmt::mp("done"))){
+    if(pmt::eqv(op, d_pmt_done)){
         d_finished = pmt::to_long(pmt::cdr(msg));
         global_block_registry.notify_blk(alias());
     } else {
@@ -733,16 +736,10 @@ namespace gr {
         pmt::pmt_t target = pmt::car(currlist);
 
         pmt::pmt_t block = pmt::car(target);
-        pmt::pmt_t port = pmt::mp("system");
 
         currlist = pmt::cdr(currlist);
         basic_block_sptr blk = global_block_registry.block_lookup(block);
-        blk->post(port, pmt::cons(pmt::mp("done"), pmt::mp(true)));
-
-        //std::cout << "notify finished --> ";
-        //pmt::print(pmt::cons(block,port));
-        //std::cout << "\n";
-
+        blk->post(d_system_port, pmt::cons(d_pmt_done, pmt::mp(true)));
         }
     }
   }