rfnoc: graph: Lock release/commit state

Property propagation and action handling depend on the release state,
but they are lengthy operations. It is therefore imperative to not
change the release/commit state during those methods.

This commit changes the following:
- Change the release state counter from an atomic to a non-atomic
  variable
- Instead, use a mutex to lock the release state counter, and use the
  same mutex for locking access to the property propagation and action
  handling

The rfnoc_graph now tries to release the graph before shutting down
blocks to make sure they don't get destroyed while those algorithms are
still running.

1 files changed, 4 insertions, 1 deletions

diff --git a/host/lib/rfnoc/rfnoc_graph.cpp b/host/lib/rfnoc/rfnoc_graph.cpp
index b3bff6c12..795ffd289 100644
--- a/host/lib/rfnoc/rfnoc_graph.cpp
+++ b/host/lib/rfnoc/rfnoc_graph.cpp
@@ -66,8 +66,11 @@ public:
 
     ~rfnoc_graph_impl()
     {
-        _graph.reset();
+        UHD_LOG_TRACE(LOG_ID, "Releasing detail::graph...");
+        _graph->release();
+        UHD_LOG_TRACE(LOG_ID, "Shutting down all blocks ...");
         _block_registry->shutdown();
+        _graph.reset();
     }
 
     /**************************************************************************