Merged mblock work-in-progress eb/mb -r4798:4808 into trunk.

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@4809 221aa14e-8319-0410-a670-987f0aec2ac5

23 files changed, 509 insertions, 106 deletions

diff --git a/configure.ac b/configure.ac
index 742593526..28f4ec938 100644
--- a/configure.ac
+++ b/configure.ac
@@ -213,7 +213,7 @@ GRC_GR_PAGER
 GRC_GR_RADIO_ASTRONOMY
 GRC_GR_TRELLIS
 GRC_GR_VIDEO_SDL
-#GRC_GR_QTGUI			dnl disabled until grc_gr_qtgui.m4 is final
+GRC_GR_QTGUI			dnl disabled until grc_gr_qtgui.m4 is final
 GRC_GR_WXGUI
 GRC_PMT
 GRC_MBLOCK			dnl this must come after GRC_PMT
diff --git a/mblock/src/lib/Makefile.am b/mblock/src/lib/Makefile.am
index 478793e97..6273e16d2 100644
--- a/mblock/src/lib/Makefile.am
+++ b/mblock/src/lib/Makefile.am
@@ -27,7 +27,8 @@ TESTS = test_mblock
 
 lib_LTLIBRARIES = libmblock.la libmblock-qa.la
 
-EXTRA_DIST = 				
+EXTRA_DIST = 				\
+	README.locking			
 
 
 # These are the source files that go into the mblock shared library
@@ -45,7 +46,9 @@ libmblock_la_SOURCES =			\
 	mb_port_simple.cc		\
 	mb_protocol_class.cc		\
 	mb_runtime.cc			\
-	mb_runtime_single_threaded.cc	\
+	mb_runtime_nop.cc		\
+	mb_runtime_placeholder.cc	\
+	mb_runtime_thread_per_mblock.cc	\
 	mb_util.cc			
 
 
@@ -69,7 +72,9 @@ include_HEADERS =			\
 	mb_port_simple.h		\
 	mb_protocol_class.h		\
 	mb_runtime.h			\
-	mb_runtime_single_threaded.h	\
+	mb_runtime_nop.h		\
+	mb_runtime_placeholder.h	\
+	mb_runtime_thread_per_mblock.h	\
 	mb_util.h			
 
 
@@ -78,6 +83,7 @@ noinst_HEADERS = 			\
 	mb_endpoint.h			\
 	mb_mblock_impl.h		\
 	mb_msg_accepter_smp.h		\
+	mbi_runtime_lock.h		\
 	qa_mblock.h			\
 	qa_mblock_prims.h		\
 	qa_mblock_send.h		
diff --git a/mblock/src/lib/README.locking b/mblock/src/lib/README.locking
new file mode 100644
index 000000000..12d4735e7
--- /dev/null
+++ b/mblock/src/lib/README.locking
@@ -0,0 +1,4 @@
+The Big Runtime Lock must be held when:
+
+Manipulating or traversing any mblock's d_port_map, d_comp_map or d_conn_table.
+
diff --git a/mblock/src/lib/mb_common.h b/mblock/src/lib/mb_common.h
index 3c9ec8e16..34c720492 100644
--- a/mblock/src/lib/mb_common.h
+++ b/mblock/src/lib/mb_common.h
@@ -26,7 +26,7 @@
 #include <stdexcept>
 #include <boost/utility.hpp>
 #include <boost/enable_shared_from_this.hpp>
-
+#include <boost/weak_ptr.hpp>
 
 /*
  * The priority type and valid range
diff --git a/mblock/src/lib/mb_mblock.cc b/mblock/src/lib/mb_mblock.cc
index bf9f5b0ce..9b8658f21 100644
--- a/mblock/src/lib/mb_mblock.cc
+++ b/mblock/src/lib/mb_mblock.cc
@@ -121,15 +121,27 @@ mb_mblock::walk_tree(mb_visitor *visitor, const std::string &path)
 }
 
 std::string
-mb_mblock::fullname() const
+mb_mblock::instance_name() const
 {
-  return d_impl->fullname();
+  return d_impl->instance_name();
 }
 
 void
-mb_mblock::set_fullname(const std::string name)
+mb_mblock::set_instance_name(const std::string name)
 {
-  d_impl->set_fullname(name);
+  d_impl->set_instance_name(name);
+}
+
+std::string
+mb_mblock::class_name() const
+{
+  return d_impl->class_name();
+}
+
+void
+mb_mblock::set_class_name(const std::string name)
+{
+  d_impl->set_class_name(name);
 }
 
 mb_mblock *
diff --git a/mblock/src/lib/mb_mblock.h b/mblock/src/lib/mb_mblock.h
index 00e4051c0..594920f91 100644
--- a/mblock/src/lib/mb_mblock.h
+++ b/mblock/src/lib/mb_mblock.h
@@ -24,7 +24,6 @@
 #include <mb_common.h>
 #include <mb_message.h>
 #include <mb_port.h>
-#include <boost/enable_shared_from_this.hpp>
 
 
 /*!
@@ -175,15 +174,21 @@ protected:
   int
   nconnections() const;
 
+  //! Set the class name
+  void set_class_name(const std::string name);
 
 public:
   virtual ~mb_mblock();
 
-  void set_fullname(const std::string name);
-  
-  //! Return full name of this block
-  std::string fullname() const;
+  //! Return instance name of this block
+  std::string instance_name() const;
+
+  //! Return the class name of this block
+  std::string class_name() const;
 
+  //! Set the instance name of this block.
+  void set_instance_name(const std::string name);
+  
   //! Return the parent of this mblock, or 0 if we're the top-level block.
   mb_mblock *parent() const;
 
diff --git a/mblock/src/lib/mb_mblock_impl.cc b/mblock/src/lib/mb_mblock_impl.cc
index a9e81e8de..1a9e50146 100644
--- a/mblock/src/lib/mb_mblock_impl.cc
+++ b/mblock/src/lib/mb_mblock_impl.cc
@@ -30,6 +30,8 @@
 #include <mb_exception.h>
 #include <mb_util.h>
 #include <mb_msg_accepter_smp.h>
+#include <mb_runtime_placeholder.h>
+#include <mbi_runtime_lock.h>
 
 
 static pmt_t s_self = pmt_intern("self");
@@ -51,7 +53,8 @@ mb_mblock_impl::comp_is_defined(const std::string &name)
 ////////////////////////////////////////////////////////////////////////
 
 mb_mblock_impl::mb_mblock_impl(mb_mblock *mb)
-  : d_mb(mb), d_mb_parent(0), d_fullname("<unknown>")
+  : d_mb(mb), d_mb_parent(0), d_runtime(mb_runtime_placeholder::singleton()),
+    d_instance_name("<unknown>"), d_class_name("mblock")
 {
 }
 
@@ -67,6 +70,8 @@ mb_mblock_impl::define_port(const std::string &port_name,
 			    bool conjugated,
 			    mb_port::port_type_t port_type)
 {
+  mbi_runtime_lock	l(this);
+
   if (port_is_defined(port_name))
     throw mbe_duplicate_port(d_mb, port_name);
 
@@ -82,6 +87,8 @@ void
 mb_mblock_impl::define_component(const std::string &name,
 				 mb_mblock_sptr component)
 {
+  mbi_runtime_lock	l(this);
+
   if (comp_is_defined(name))	// check for duplicate name
     throw mbe_duplicate_component(d_mb, name);
 
@@ -95,6 +102,8 @@ mb_mblock_impl::connect(const std::string &comp_name1,
 			const std::string &comp_name2,
 			const std::string &port_name2)
 {
+  mbi_runtime_lock	l(this);
+
   mb_endpoint	ep0 = check_and_resolve_endpoint(comp_name1, port_name1);
   mb_endpoint	ep1 = check_and_resolve_endpoint(comp_name2, port_name2);
 
@@ -113,24 +122,32 @@ mb_mblock_impl::disconnect(const std::string &comp_name1,
 			   const std::string &comp_name2,
 			   const std::string &port_name2)
 {
+  mbi_runtime_lock	l(this);
+
   d_conn_table.disconnect(comp_name1, port_name1, comp_name2, port_name2);
 }
 
 void
 mb_mblock_impl::disconnect_component(const std::string component_name)
 {
+  mbi_runtime_lock	l(this);
+
   d_conn_table.disconnect_component(component_name);
 }
 
 void
 mb_mblock_impl::disconnect_all()
 {
+  mbi_runtime_lock	l(this);
+
   d_conn_table.disconnect_all();
 }
 
 int
-mb_mblock_impl::nconnections() const
+mb_mblock_impl::nconnections()
 {
+  mbi_runtime_lock	l(this);
+
   return d_conn_table.nconnections();
 }
 
@@ -219,6 +236,7 @@ mb_mblock_impl::walk_tree(mb_visitor *visitor, const std::string &path)
 mb_msg_accepter_sptr
 mb_mblock_impl::make_accepter(const std::string port_name)
 {
+  // FIXME this should probably use some kind of configurable factory
   mb_msg_accepter *ma =
     new mb_msg_accepter_smp(d_mb->shared_from_this(),
 			    pmt_intern(port_name));
@@ -252,8 +270,14 @@ mb_mblock_impl::component(const std::string &comp_name)
 }
 
 void
-mb_mblock_impl::set_fullname(const std::string &name)
+mb_mblock_impl::set_instance_name(const std::string &name)
+{
+  d_instance_name = name;
+}
+
+void
+mb_mblock_impl::set_class_name(const std::string &name)
 {
-  d_fullname = name;
+  d_class_name = name;
 }
 
diff --git a/mblock/src/lib/mb_mblock_impl.h b/mblock/src/lib/mb_mblock_impl.h
index 38cb5d5f6..fc0fa6943 100644
--- a/mblock/src/lib/mb_mblock_impl.h
+++ b/mblock/src/lib/mb_mblock_impl.h
@@ -39,8 +39,10 @@ class mb_mblock_impl : boost::noncopyable
 {
   mb_mblock		       *d_mb;		// pointer to our associated mblock
   mb_mblock		       *d_mb_parent;	// pointer to our parent
+  mb_runtime		       *d_runtime;	// pointer to runtime
 
-  std::string			d_fullname;	// hierarchical name
+  std::string			d_instance_name;    // hierarchical name
+  std::string			d_class_name;	    // name of this (derived) class
 
   mb_port_map_t			d_port_map;	// our ports
   mb_comp_map_t			d_comp_map;	// our components
@@ -136,7 +138,7 @@ public:
    * \brief Return number of connections (QA mostly)
    */
   int
-  nconnections() const;
+  nconnections();
 
   bool
   walk_tree(mb_visitor *visitor, const std::string &path="");
@@ -147,11 +149,17 @@ public:
   mb_msg_queue &
   msgq() { return d_msgq; }
 
-  //! Return full name of this block
-  std::string fullname() const { return d_fullname; }
+  //! Return instance name of this block
+  std::string instance_name() const { return d_instance_name; }
 
-  //! Set the name of this block
-  void set_fullname(const std::string &name);
+  //! Set the instance name of this block
+  void set_instance_name(const std::string &name);
+
+  //! Return the class name of this block
+  std::string class_name() const { return d_class_name; }
+
+  //! Set the class name
+  void set_class_name(const std::string &name);
 
   /*!
    * \brief If bound, store endpoint from the other end of the connection.
@@ -165,15 +173,20 @@ public:
   lookup_other_endpoint(const mb_port *port, mb_endpoint *ep);
 
 
-  mb_mblock *
-  mblock() const { return d_mb; }
+  //! Return point to associated mblock
+  mb_mblock *mblock() const { return d_mb; }
+
+  //! Return pointer to the parent of our mblock
+  mb_mblock *mblock_parent() const { return d_mb_parent; }
 
-  mb_mblock *
-  mblock_parent() const { return d_mb_parent; }
+  //! Lookup a component by name
+  mb_mblock_sptr component(const std::string &comp_name);
 
-  mb_mblock_sptr
-  component(const std::string &comp_name);
+  //! Return the runtime instance
+  mb_runtime *runtime() { return d_runtime; }
 
+  //! Set the runtime instance
+  void set_runtime(mb_runtime *runtime) { d_runtime = runtime; }
 
   /*
    * Our implementation methods
diff --git a/mblock/src/lib/mb_msg_accepter_smp.cc b/mblock/src/lib/mb_msg_accepter_smp.cc
index 9e543979e..3123b329c 100644
--- a/mblock/src/lib/mb_msg_accepter_smp.cc
+++ b/mblock/src/lib/mb_msg_accepter_smp.cc
@@ -45,6 +45,4 @@ mb_msg_accepter_smp::operator()(pmt_t signal, pmt_t data,
   mb_message_sptr msg = mb_make_message(signal, data, metadata, priority);
   msg->set_port_id(d_port_name);
   d_mb->impl()->msgq().insert(msg);
-
-  // FIXME tell runtime that we're ready to run
 }
diff --git a/mblock/src/lib/mb_msg_queue.cc b/mblock/src/lib/mb_msg_queue.cc
index 8afdea07e..79e245ad6 100644
--- a/mblock/src/lib/mb_msg_queue.cc
+++ b/mblock/src/lib/mb_msg_queue.cc
@@ -25,9 +25,9 @@
 #include <mb_msg_queue.h>
 #include <mb_message.h>
 
-// FIXME turn this into a template so we can use it for the runq of mblocks too
 
 mb_msg_queue::mb_msg_queue()
+  : d_not_empty(&d_mutex)
 {
 }
 
@@ -51,14 +51,21 @@ mb_msg_queue::insert(mb_message_sptr msg)
     d_queue[q].tail = msg;
     msg->d_next.reset();	// msg->d_next = 0;
   }
+
   // FIXME set bit in bitmap
+
+  d_not_empty.signal();
 }
 
+/*
+ * Delete highest pri message from the queue and return it.
+ * Returns equivalent of zero pointer if queue is empty.
+ *
+ * Caller must be holding d_mutex
+ */
 mb_message_sptr
-mb_msg_queue::get_highest_pri_msg()
+mb_msg_queue::get_highest_pri_msg_helper()
 {
-  omni_mutex_lock	l(d_mutex);
-
   // FIXME use bitmap and ffz to find best queue in O(1)
 
   for (mb_pri_t q = 0; q <= MB_PRI_WORST; q++){
@@ -78,3 +85,27 @@ mb_msg_queue::get_highest_pri_msg()
 
   return mb_message_sptr();	// equivalent of a zero pointer
 }
+
+
+mb_message_sptr
+mb_msg_queue::get_highest_pri_msg_nowait()
+{
+  omni_mutex_lock	l(d_mutex);
+
+  return get_highest_pri_msg_helper();
+}
+
+mb_message_sptr
+mb_msg_queue::get_highest_pri_msg()
+{
+  omni_mutex_lock l(d_mutex);
+
+  while (1){
+    mb_message_sptr msg = get_highest_pri_msg_helper();
+    if (msg)			// Got one; return it
+      return msg;
+
+    d_not_empty.wait();		// Wait for something
+  }
+}
+
diff --git a/mblock/src/lib/mb_msg_queue.h b/mblock/src/lib/mb_msg_queue.h
index 57f6dd0b3..7977b7d80 100644
--- a/mblock/src/lib/mb_msg_queue.h
+++ b/mblock/src/lib/mb_msg_queue.h
@@ -37,10 +37,13 @@ class mb_msg_queue : boost::noncopyable
     bool empty_p() const { return head == 0; }
   };
 
-  omni_mutex	d_mutex;
+  omni_mutex	 d_mutex;
+  omni_condition d_not_empty;	// reader waits on this
 
   // FIXME add bitmap to indicate which queues are non-empty.
-  subq		d_queue[MB_NPRI];
+  subq		 d_queue[MB_NPRI];
+
+  mb_message_sptr get_highest_pri_msg_helper();
 
 public:
   mb_msg_queue();
@@ -53,6 +56,12 @@ public:
    * \brief Delete highest pri message from the queue and return it.
    * Returns equivalent of zero pointer if queue is empty.
    */
+  mb_message_sptr get_highest_pri_msg_nowait();
+
+  /*
+   * \brief Delete highest pri message from the queue and return it.
+   * If the queue is empty, this call blocks until it can return a message.
+   */
   mb_message_sptr get_highest_pri_msg();
 };
 
diff --git a/mblock/src/lib/mb_port_simple.cc b/mblock/src/lib/mb_port_simple.cc
index 1315b6172..80cb65efb 100644
--- a/mblock/src/lib/mb_port_simple.cc
+++ b/mblock/src/lib/mb_port_simple.cc
@@ -29,6 +29,7 @@
 #include <mb_mblock.h>
 #include <mb_mblock_impl.h>
 #include <assert.h>
+#include <mbi_runtime_lock.h>
 
 
 mb_port_simple::mb_port_simple(mb_mblock *mblock,
@@ -49,7 +50,7 @@ void
 mb_port_simple::send(pmt_t signal, pmt_t data, pmt_t metadata, mb_pri_t priority)
 {
   if (port_type() == mb_port::RELAY)  // Can't send directly to a RELAY port
-    throw mbe_invalid_port_type(mblock(), mblock()->fullname(), port_name());
+    throw mbe_invalid_port_type(mblock(), mblock()->instance_name(), port_name());
 
   mb_msg_accepter_sptr  accepter = find_accepter(this);
   if (accepter)
@@ -66,6 +67,8 @@ mb_port_simple::find_accepter(mb_port_simple *start)
   mb_endpoint 		peer_ep;
   mb_msg_accepter_sptr	r;
 
+  mbi_runtime_lock	l(p->mblock());
+
   // Set up initial context.
 
   switch(p->port_type()){
diff --git a/mblock/src/lib/mb_runtime.cc b/mblock/src/lib/mb_runtime.cc
index fa762270b..34a0af358 100644
--- a/mblock/src/lib/mb_runtime.cc
+++ b/mblock/src/lib/mb_runtime.cc
@@ -24,12 +24,12 @@
 #endif
 
 #include <mb_runtime.h>
-#include <mb_runtime_single_threaded.h>
+#include <mb_runtime_thread_per_mblock.h>
 
 mb_runtime_sptr
 mb_make_runtime()
 {
-  return mb_runtime_sptr(new mb_runtime_single_threaded());
+  return mb_runtime_sptr(new mb_runtime_thread_per_mblock());
 }
 
 mb_runtime::~mb_runtime()
diff --git a/mblock/src/lib/mb_runtime.h b/mblock/src/lib/mb_runtime.h
index 9b47537b2..0929e30dc 100644
--- a/mblock/src/lib/mb_runtime.h
+++ b/mblock/src/lib/mb_runtime.h
@@ -22,6 +22,7 @@
 #define INCLUDED_MB_RUNTIME_H
 
 #include <mb_common.h>
+#include <omnithread.h>
 
 /*!
  * \brief Public constructor (factory) for mb_runtime objects.
@@ -33,8 +34,11 @@ mb_runtime_sptr mb_make_runtime();
  *
  * There should generally be only a single instance of this class.
  */
-class mb_runtime : boost::noncopyable
+class mb_runtime : boost::noncopyable,
+		   public boost::enable_shared_from_this<mb_runtime>
 {
+  omni_mutex	d_brl;		// big runtime lock (avoid using this if possible...)
+
 public:
   mb_runtime(){}
   virtual ~mb_runtime();
@@ -49,6 +53,24 @@ public:
    * \returns true if the system ran successfully.
    */
   virtual bool run(mb_mblock_sptr top) = 0;
+
+
+  // ----------------------------------------------------------------
+  // Stuff from here down is really private to the implementation...
+  // ----------------------------------------------------------------
+
+  /*!
+   * \brief lock the big runtime lock
+   * \implementation
+   */
+  inline void lock() { d_brl.lock(); }
+
+  /*!
+   * \brief unlock the big runtime lock
+   * \implementation
+   */
+  inline void unlock() { d_brl.unlock(); }
+
 };
 
 #endif /* INCLUDED_MB_RUNTIME_H */
diff --git a/mblock/src/lib/mb_runtime_single_threaded.cc b/mblock/src/lib/mb_runtime_nop.cc
index dc8597aeb..a19f0793a 100644
--- a/mblock/src/lib/mb_runtime_single_threaded.cc
+++ b/mblock/src/lib/mb_runtime_nop.cc
@@ -22,29 +22,35 @@
 #ifdef HAVE_CONFIG_H
 #include <config.h>
 #endif
-#include <mb_runtime_single_threaded.h>
+#include <mb_runtime_nop.h>
 #include <mb_mblock.h>
 
+mb_runtime_sptr 
+mb_make_runtime_nop()
+{
+  return mb_runtime_sptr(new mb_runtime_nop());
+}
 
-mb_runtime_single_threaded::mb_runtime_single_threaded()
+
+mb_runtime_nop::mb_runtime_nop()
 {
   // nop for now
 }
 
-mb_runtime_single_threaded::~mb_runtime_single_threaded()
+mb_runtime_nop::~mb_runtime_nop()
 {
   // nop for now
 }
 
 bool
-mb_runtime_single_threaded::run(mb_mblock_sptr top)
+mb_runtime_nop::run(mb_mblock_sptr top)
 {
   class initial_visitor : public mb_visitor
   {
   public:
     bool operator()(mb_mblock *mblock, const std::string &path)
     {
-      mblock->set_fullname(path);
+      mblock->set_instance_name(path);
       mblock->init_fsm();
       return true;
     }
@@ -52,9 +58,7 @@ mb_runtime_single_threaded::run(mb_mblock_sptr top)
 
   initial_visitor	visitor;
 
-  d_top = top;		// remember top of tree
-
-  d_top->walk_tree(&visitor);
+  top->walk_tree(&visitor);
 
   return true;
 }
diff --git a/mblock/src/lib/mb_runtime_nop.h b/mblock/src/lib/mb_runtime_nop.h
new file mode 100644
index 000000000..dc7887991
--- /dev/null
+++ b/mblock/src/lib/mb_runtime_nop.h
@@ -0,0 +1,44 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2007 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 2, 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 this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#ifndef INCLUDED_MB_RUNTIME_NOP_H
+#define INCLUDED_MB_RUNTIME_NOP_H
+
+#include <mb_runtime.h>
+
+/*!
+ * \brief Public constructor (factory) for mb_runtime_nop objects.
+ */
+mb_runtime_sptr mb_make_runtime_nop();
+
+/*!
+ * \brief Concrete runtime that does nothing.  Used only during early QA tests.
+ */
+class mb_runtime_nop : public mb_runtime
+{
+
+public:
+  mb_runtime_nop();
+  ~mb_runtime_nop();
+
+  bool run(mb_mblock_sptr top);
+};
+
+#endif /* INCLUDED_MB_RUNTIME_NOP_H */
diff --git a/mblock/src/lib/mb_runtime_placeholder.cc b/mblock/src/lib/mb_runtime_placeholder.cc
new file mode 100644
index 000000000..5ce7cc2ac
--- /dev/null
+++ b/mblock/src/lib/mb_runtime_placeholder.cc
@@ -0,0 +1,57 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2007 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 2, 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 this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <mb_runtime_placeholder.h>
+#include <mb_mblock.h>
+#include <mb_exception.h>
+
+
+static mb_runtime *s_singleton = 0;
+
+
+mb_runtime_placeholder::mb_runtime_placeholder()
+{
+  // nop
+}
+
+mb_runtime_placeholder::~mb_runtime_placeholder()
+{
+  // nop
+}
+
+bool
+mb_runtime_placeholder::run(mb_mblock_sptr top)
+{
+  throw mbe_not_implemented(top.get(), "mb_runtime_placeholder::run");
+}
+
+mb_runtime *
+mb_runtime_placeholder::singleton()
+{
+  if (s_singleton)
+    return s_singleton;
+
+  s_singleton = new mb_runtime_placeholder();
+  return s_singleton;
+}
diff --git a/mblock/src/lib/mb_runtime_placeholder.h b/mblock/src/lib/mb_runtime_placeholder.h
new file mode 100644
index 000000000..b55d39f94
--- /dev/null
+++ b/mblock/src/lib/mb_runtime_placeholder.h
@@ -0,0 +1,50 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2007 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 2, 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 this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#ifndef INCLUDED_MB_RUNTIME_PLACEHOLDER_H
+#define INCLUDED_MB_RUNTIME_PLACEHOLDER_H
+
+#include <mb_runtime.h>
+
+/*!
+ * \brief Concrete runtime that serves as a placeholder until the real
+ * runtime is known.
+ *
+ * The singleton instance of this class is installed in the d_runtime
+ * instance variable of each mb_mblock_impl at construction time.
+ * Having a valid instance of runtime removes the "pre runtime::run"
+ * corner case, and allows us to lock and unlock the big runtime lock
+ * even though there's no "real runtime" yet.
+ */
+class mb_runtime_placeholder : public mb_runtime
+{
+
+public:
+  mb_runtime_placeholder();
+  ~mb_runtime_placeholder();
+
+  //! throws mbe_not_implemented
+  bool run(mb_mblock_sptr top);
+
+  //! Return the placeholder singleton
+  static mb_runtime *singleton();
+};
+
+#endif /* INCLUDED_MB_RUNTIME_PLACEHOLDER_H */
diff --git a/mblock/src/lib/mb_runtime_thread_per_mblock.cc b/mblock/src/lib/mb_runtime_thread_per_mblock.cc
new file mode 100644
index 000000000..925dcdc45
--- /dev/null
+++ b/mblock/src/lib/mb_runtime_thread_per_mblock.cc
@@ -0,0 +1,65 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2007 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 2, 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 this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <mb_runtime_thread_per_mblock.h>
+#include <mb_mblock.h>
+#include <mb_mblock_impl.h>
+
+
+mb_runtime_thread_per_mblock::mb_runtime_thread_per_mblock()
+{
+  // nop for now
+}
+
+mb_runtime_thread_per_mblock::~mb_runtime_thread_per_mblock()
+{
+  // nop for now
+}
+
+bool
+mb_runtime_thread_per_mblock::run(mb_mblock_sptr top)
+{
+  class initial_visitor : public mb_visitor
+  {
+    mb_runtime  *d_rt;
+
+  public:
+    initial_visitor(mb_runtime *rt) : d_rt(rt) {}
+    bool operator()(mb_mblock *mblock, const std::string &path)
+    {
+      mblock->impl()->set_runtime(d_rt);
+      mblock->set_instance_name(path);
+      mblock->init_fsm();
+      return true;
+    }
+  };
+
+  initial_visitor	visitor(this);
+
+  d_top = top;		// remember top of tree
+
+  d_top->walk_tree(&visitor);
+
+  return true;
+}
diff --git a/mblock/src/lib/mb_runtime_single_threaded.h b/mblock/src/lib/mb_runtime_thread_per_mblock.h
index b56e0a5e1..cef756ecd 100644
--- a/mblock/src/lib/mb_runtime_single_threaded.h
+++ b/mblock/src/lib/mb_runtime_thread_per_mblock.h
@@ -18,25 +18,23 @@
  * with this program; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
-#ifndef INCLUDED_MB_RUNTIME_SINGLE_THREADED_H
-#define INCLUDED_MB_RUNTIME_SINGLE_THREADED_H
+#ifndef INCLUDED_MB_RUNTIME_THREAD_PER_MBLOCK_H
+#define INCLUDED_MB_RUNTIME_THREAD_PER_MBLOCK_H
 
 #include <mb_runtime.h>
 
 /*!
  * \brief Concrete runtime that uses a single thread for all work.
  */
-class mb_runtime_single_threaded : public mb_runtime
+class mb_runtime_thread_per_mblock : public mb_runtime
 {
   mb_mblock_sptr	d_top;		// top mblock
 
 public:
-  mb_runtime_single_threaded();
-  ~mb_runtime_single_threaded();
+  mb_runtime_thread_per_mblock();
+  ~mb_runtime_thread_per_mblock();
 
   bool run(mb_mblock_sptr top);
 };
 
-
-
-#endif /* INCLUDED_MB_RUNTIME_SINGLE_THREADED_H */
+#endif /* INCLUDED_MB_RUNTIME_THREAD_PER_MBLOCK_H */
diff --git a/mblock/src/lib/mbi_runtime_lock.h b/mblock/src/lib/mbi_runtime_lock.h
new file mode 100644
index 000000000..3138a7e1e
--- /dev/null
+++ b/mblock/src/lib/mbi_runtime_lock.h
@@ -0,0 +1,61 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2007 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 2, 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 this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef INCLUDED_MBI_RUNTIME_LOCK_H
+#define INCLUDED_MBI_RUNTIME_LOCK_H
+
+#include <mb_runtime.h>
+#include <mb_mblock_impl.h>
+#include <boost/utility.hpp>
+
+/*!
+ * \brief acquire and release big runtime lock
+ *
+ * As an alternative to:
+ * {
+ *   rt->lock();
+ *   .....
+ *   rt->unlock();
+ * }
+ *
+ * you can use a single instance of the mbi_runtime_lock class:
+ *
+ * {
+ *   mbi_runtime_lock l(rt);
+ *   ....
+ * }
+ *
+ * This has the advantage that rt->unlock() will be called automatically
+ * when an exception is thrown.
+ */
+
+class mbi_runtime_lock : boost::noncopyable {
+  mb_runtime	*d_rt;
+public:
+  mbi_runtime_lock(mb_runtime *rt) : d_rt(rt) { d_rt->lock(); }
+  mbi_runtime_lock(mb_mblock_impl *mi) : d_rt(mi->runtime()) { d_rt->lock(); }
+  mbi_runtime_lock(mb_mblock *mb) : d_rt(mb->impl()->runtime()) { d_rt->lock(); }
+  ~mbi_runtime_lock(void) { d_rt->unlock(); }
+
+};
+
+#endif /* INCLUDED_MBI_RUNTIME_LOCK_H */
+
diff --git a/mblock/src/lib/qa_mblock_prims.cc b/mblock/src/lib/qa_mblock_prims.cc
index 7385a17ef..79ed5a21e 100644
--- a/mblock/src/lib/qa_mblock_prims.cc
+++ b/mblock/src/lib/qa_mblock_prims.cc
@@ -95,7 +95,6 @@ dp_3::~dp_3(){}
 void
 qa_mblock_prims::test_define_ports()
 {
-  mb_runtime_sptr	rt = mb_make_runtime();
   // std::vector<mb_port_sptr>	intf;
 
   mb_mblock_sptr	mb1 = mb_mblock_sptr(new dp_1());
@@ -175,7 +174,6 @@ dc_not_ok::~dc_not_ok(){}
 void
 qa_mblock_prims::test_define_components()
 {
-  mb_runtime_sptr	rt = mb_make_runtime();
   mb_mblock_sptr	mb1 = mb_mblock_sptr(new dc_ok());	// OK
 
   // raises pmt_exception because of duplicate component definition of "c0"
@@ -317,8 +315,6 @@ qa_mblock_prims::test_connect()
 			 pmt_list1(pmt_intern("in")),		// in
 			 pmt_list1(pmt_intern("out")));		// out
 
-
-  mb_runtime_sptr	rt = mb_make_runtime();
   mb_mblock_sptr	mb0 = mb_mblock_sptr(new tc_0());
 }
 
@@ -330,7 +326,7 @@ qa_mblock_prims::test_msg_queue()
   mb_msg_queue	q;
 
   // check initial state
-  CPPUNIT_ASSERT(q.get_highest_pri_msg() == 0);
+  CPPUNIT_ASSERT(q.get_highest_pri_msg_nowait() == 0);
 
   CPPUNIT_ASSERT(MB_NPRI >= 5);	// sanity check for this test
 
@@ -340,11 +336,11 @@ qa_mblock_prims::test_msg_queue()
   q.insert(mb_make_message(PMT_NIL, pmt_from_long(1), PMT_NIL, MB_PRI_BEST + 2));
   q.insert(mb_make_message(PMT_NIL, pmt_from_long(2), PMT_NIL, MB_PRI_BEST + 2));
   
-  CPPUNIT_ASSERT_EQUAL(0L, pmt_to_long(q.get_highest_pri_msg()->data()));
-  CPPUNIT_ASSERT_EQUAL(1L, pmt_to_long(q.get_highest_pri_msg()->data()));
-  CPPUNIT_ASSERT_EQUAL(2L, pmt_to_long(q.get_highest_pri_msg()->data()));
+  CPPUNIT_ASSERT_EQUAL(0L, pmt_to_long(q.get_highest_pri_msg_nowait()->data()));
+  CPPUNIT_ASSERT_EQUAL(1L, pmt_to_long(q.get_highest_pri_msg_nowait()->data()));
+  CPPUNIT_ASSERT_EQUAL(2L, pmt_to_long(q.get_highest_pri_msg_nowait()->data()));
 
-  CPPUNIT_ASSERT(q.get_highest_pri_msg() == 0);
+  CPPUNIT_ASSERT(q.get_highest_pri_msg_nowait() == 0);
 
 
   // insert messages of different priorities in pseudo-random order
@@ -361,19 +357,19 @@ qa_mblock_prims::test_msg_queue()
   q.insert(mb_make_message(PMT_NIL, PMT_NIL, PMT_NIL, MB_PRI_BEST + 1));
 
   // confirm that they come out in order
-  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 0, q.get_highest_pri_msg()->priority());
-  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 0, q.get_highest_pri_msg()->priority());
-  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 1, q.get_highest_pri_msg()->priority());
-  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 1, q.get_highest_pri_msg()->priority());
-  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 2, q.get_highest_pri_msg()->priority());
-  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 2, q.get_highest_pri_msg()->priority());
-  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 3, q.get_highest_pri_msg()->priority());
-  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 3, q.get_highest_pri_msg()->priority());
-  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 4, q.get_highest_pri_msg()->priority());
-  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 4, q.get_highest_pri_msg()->priority());
+  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 0, q.get_highest_pri_msg_nowait()->priority());
+  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 0, q.get_highest_pri_msg_nowait()->priority());
+  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 1, q.get_highest_pri_msg_nowait()->priority());
+  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 1, q.get_highest_pri_msg_nowait()->priority());
+  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 2, q.get_highest_pri_msg_nowait()->priority());
+  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 2, q.get_highest_pri_msg_nowait()->priority());
+  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 3, q.get_highest_pri_msg_nowait()->priority());
+  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 3, q.get_highest_pri_msg_nowait()->priority());
+  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 4, q.get_highest_pri_msg_nowait()->priority());
+  CPPUNIT_ASSERT_EQUAL(MB_PRI_BEST + 4, q.get_highest_pri_msg_nowait()->priority());
   
   // check final state
-  CPPUNIT_ASSERT(q.get_highest_pri_msg() == 0);
+  CPPUNIT_ASSERT(q.get_highest_pri_msg_nowait() == 0);
 }
 
 ////////////////////////////////////////////////////////////////
@@ -397,10 +393,10 @@ qa_mblock_prims::test_make_accepter()
 
   pmt_t cs = pmt_intern("cs");
 
-  mb_message_sptr msg = mb->impl()->msgq().get_highest_pri_msg();
+  mb_message_sptr msg = mb->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(pmt_eq(cs, msg->port_id()));	      // confirm that port_id is set
   CPPUNIT_ASSERT_EQUAL(0L, pmt_to_long(msg->data())); // and that data is correct
 
-  CPPUNIT_ASSERT_EQUAL(1L, pmt_to_long(mb->impl()->msgq().get_highest_pri_msg()->data()));
-  CPPUNIT_ASSERT_EQUAL(2L, pmt_to_long(mb->impl()->msgq().get_highest_pri_msg()->data()));
+  CPPUNIT_ASSERT_EQUAL(1L, pmt_to_long(mb->impl()->msgq().get_highest_pri_msg_nowait()->data()));
+  CPPUNIT_ASSERT_EQUAL(2L, pmt_to_long(mb->impl()->msgq().get_highest_pri_msg_nowait()->data()));
 }
diff --git a/mblock/src/lib/qa_mblock_send.cc b/mblock/src/lib/qa_mblock_send.cc
index ff86adbf3..46d6b6440 100644
--- a/mblock/src/lib/qa_mblock_send.cc
+++ b/mblock/src/lib/qa_mblock_send.cc
@@ -28,6 +28,7 @@
 #include <cppunit/TestAssert.h>
 #include <mb_mblock.h>
 #include <mb_runtime.h>
+#include <mb_runtime_nop.h>		// QA only
 #include <mb_protocol_class.h>
 #include <mb_exception.h>
 #include <mb_msg_queue.h>
@@ -86,10 +87,10 @@ sr1::~sr1(){}
 void
 sr1::init_fsm()
 {
-  // std::cout << fullname() << "[sr1]: init_fsm\n";
+  // std::cout << instance_name() << "[sr1]: init_fsm\n";
 
   // send two messages to each port
-  pmt_t our_name = pmt_intern(fullname());
+  pmt_t our_name = pmt_intern(instance_name());
   d_p1->send(s_status, pmt_list3(our_name, s_p1, pmt_from_long(0)));
   d_p1->send(s_status, pmt_list3(our_name, s_p1, pmt_from_long(1)));
 
@@ -127,10 +128,10 @@ sr0::~sr0(){}
 void
 sr0::init_fsm()
 {
-  // std::cout << fullname() << "[sr0]: init_fsm\n";
+  // std::cout << instance_name() << "[sr0]: init_fsm\n";
 
   // send two messages to p0
-  pmt_t our_name = pmt_intern(fullname());
+  pmt_t our_name = pmt_intern(instance_name());
   d_p0->send(s_control, pmt_list3(our_name, s_p0, pmt_from_long(0)));
   d_p0->send(s_control, pmt_list3(our_name, s_p0, pmt_from_long(1)));
 }
@@ -149,21 +150,21 @@ qa_mblock_send::test_simple_routing()
 
   mb_message_sptr msg;
 
-  mb_runtime_sptr rt = mb_make_runtime();
+  mb_runtime_sptr rt = mb_make_runtime_nop();
   mb_mblock_sptr mb0 = mb_mblock_sptr(new sr0());
   rt->run(mb0);
 
   // Reach into the guts and see if the messages ended up where they should have
 
   // mb0 should have received two messages sent from mb1 via its p1
-  msg = mb0->impl()->msgq().get_highest_pri_msg();
+  msg = mb0->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(msg);
   // std::cerr << msg->data() << std::endl;
   CPPUNIT_ASSERT_EQUAL(s_p0, msg->port_id());
   CPPUNIT_ASSERT(pmt_equal(pmt_list3(pmt_intern("top/mb1"), s_p1, pmt_from_long(0)),
 			   msg->data()));
 
-  msg = mb0->impl()->msgq().get_highest_pri_msg();
+  msg = mb0->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(msg);
   // std::cerr << msg->data() << std::endl;
   CPPUNIT_ASSERT_EQUAL(s_p0, msg->port_id());
@@ -176,28 +177,28 @@ qa_mblock_send::test_simple_routing()
 
   mb_mblock_sptr mb1 = mb0->impl()->component("mb1");
 
-  msg = mb1->impl()->msgq().get_highest_pri_msg();
+  msg = mb1->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(msg);
   // std::cerr << msg->data() << std::endl;
   CPPUNIT_ASSERT_EQUAL(s_p1, msg->port_id());
   CPPUNIT_ASSERT(pmt_equal(pmt_list3(pmt_intern("top"), s_p0, pmt_from_long(0)),
 			   msg->data()));
 
-  msg = mb1->impl()->msgq().get_highest_pri_msg();
+  msg = mb1->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(msg);
   // std::cerr << msg->data() << std::endl;
   CPPUNIT_ASSERT_EQUAL(s_p1, msg->port_id());
   CPPUNIT_ASSERT(pmt_equal(pmt_list3(pmt_intern("top"), s_p0, pmt_from_long(1)),
 			   msg->data()));
 
-  msg = mb1->impl()->msgq().get_highest_pri_msg();
+  msg = mb1->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(msg);
   // std::cerr << msg->data() << std::endl;
   CPPUNIT_ASSERT_EQUAL(s_p3, msg->port_id());
   CPPUNIT_ASSERT(pmt_equal(pmt_list3(pmt_intern("top/mb2"), s_p2, pmt_from_long(0)),
 			   msg->data()));
 
-  msg = mb1->impl()->msgq().get_highest_pri_msg();
+  msg = mb1->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(msg);
   // std::cerr << msg->data() << std::endl;
   CPPUNIT_ASSERT_EQUAL(s_p3, msg->port_id());
@@ -210,14 +211,14 @@ qa_mblock_send::test_simple_routing()
 
   mb_mblock_sptr mb2 = mb0->impl()->component("mb2");
 
-  msg = mb2->impl()->msgq().get_highest_pri_msg();
+  msg = mb2->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(msg);
   // std::cerr << msg->data() << std::endl;
   CPPUNIT_ASSERT_EQUAL(s_p3, msg->port_id());
   CPPUNIT_ASSERT(pmt_equal(pmt_list3(pmt_intern("top/mb1"), s_p2, pmt_from_long(0)),
 			   msg->data()));
 
-  msg = mb2->impl()->msgq().get_highest_pri_msg();
+  msg = mb2->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(msg);
   // std::cerr << msg->data() << std::endl;
   CPPUNIT_ASSERT_EQUAL(s_p3, msg->port_id());
@@ -253,10 +254,10 @@ rr2::~rr2(){}
 void
 rr2::init_fsm()
 {
-  // std::cout << fullname() << "[rr2]: init_fsm\n";
+  // std::cout << instance_name() << "[rr2]: init_fsm\n";
 
   // send two messages via p1
-  pmt_t our_name = pmt_intern(fullname());
+  pmt_t our_name = pmt_intern(instance_name());
   d_p1->send(s_status, pmt_list3(our_name, s_p1, pmt_from_long(0)));
   d_p1->send(s_status, pmt_list3(our_name, s_p1, pmt_from_long(1)));
 }
@@ -321,7 +322,7 @@ qa_mblock_send::test_relay_routing_1()
 {
   mb_message_sptr msg;
 
-  mb_runtime_sptr rt = mb_make_runtime();
+  mb_runtime_sptr rt = mb_make_runtime_nop();
   mb_mblock_sptr  top = mb_mblock_sptr(new rr0_a());
   rt->run(top);
 
@@ -335,14 +336,14 @@ qa_mblock_send::test_relay_routing_1()
   // c0c0 should have received
   //   two message from c1 via its p2
 
-  msg = c0c0->impl()->msgq().get_highest_pri_msg();
+  msg = c0c0->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(msg);
   //std::cerr << msg->data() << std::endl;
   CPPUNIT_ASSERT_EQUAL(s_p2, msg->port_id());
   CPPUNIT_ASSERT(pmt_equal(pmt_list3(pmt_intern("top/c1"), s_p1, pmt_from_long(0)),
 			   msg->data()));
 
-  msg = c0c0->impl()->msgq().get_highest_pri_msg();
+  msg = c0c0->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(msg);
   //std::cerr << msg->data() << std::endl;
   CPPUNIT_ASSERT_EQUAL(s_p2, msg->port_id());
@@ -352,14 +353,14 @@ qa_mblock_send::test_relay_routing_1()
   // c1 should have received
   //   two message from c0c0 via its p2
 
-  msg = c1->impl()->msgq().get_highest_pri_msg();
+  msg = c1->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(msg);
   //std::cerr << msg->data() << std::endl;
   CPPUNIT_ASSERT_EQUAL(s_p2, msg->port_id());
   CPPUNIT_ASSERT(pmt_equal(pmt_list3(pmt_intern("top/c0/c0"), s_p1, pmt_from_long(0)),
 			   msg->data()));
 
-  msg = c1->impl()->msgq().get_highest_pri_msg();
+  msg = c1->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(msg);
   //std::cerr << msg->data() << std::endl;
   CPPUNIT_ASSERT_EQUAL(s_p2, msg->port_id());
@@ -402,7 +403,7 @@ qa_mblock_send::test_relay_routing_2()
 {
   mb_message_sptr msg;
 
-  mb_runtime_sptr rt = mb_make_runtime();
+  mb_runtime_sptr rt = mb_make_runtime_nop();
   mb_mblock_sptr  top = mb_mblock_sptr(new rr0_b());
   rt->run(top);
 
@@ -417,14 +418,14 @@ qa_mblock_send::test_relay_routing_2()
   // c0c0 should have received
   //   two message from c1c0 via its p2
 
-  msg = c0c0->impl()->msgq().get_highest_pri_msg();
+  msg = c0c0->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(msg);
   // std::cerr << msg->data() << std::endl;
   CPPUNIT_ASSERT_EQUAL(s_p2, msg->port_id());
   CPPUNIT_ASSERT(pmt_equal(pmt_list3(pmt_intern("top/c1/c0"), s_p1, pmt_from_long(0)),
 			   msg->data()));
 
-  msg = c0c0->impl()->msgq().get_highest_pri_msg();
+  msg = c0c0->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(msg);
   // std::cerr << msg->data() << std::endl;
   CPPUNIT_ASSERT_EQUAL(s_p2, msg->port_id());
@@ -434,14 +435,14 @@ qa_mblock_send::test_relay_routing_2()
   // c1c0 should have received
   //   two message from c0c0 via its p2
 
-  msg = c1c0->impl()->msgq().get_highest_pri_msg();
+  msg = c1c0->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(msg);
   // std::cerr << msg->data() << std::endl;
   CPPUNIT_ASSERT_EQUAL(s_p2, msg->port_id());
   CPPUNIT_ASSERT(pmt_equal(pmt_list3(pmt_intern("top/c0/c0"), s_p1, pmt_from_long(0)),
 			   msg->data()));
 
-  msg = c1c0->impl()->msgq().get_highest_pri_msg();
+  msg = c1c0->impl()->msgq().get_highest_pri_msg_nowait();
   CPPUNIT_ASSERT(msg);
   // std::cerr << msg->data() << std::endl;
   CPPUNIT_ASSERT_EQUAL(s_p2, msg->port_id());