Second try

src/dds/rs-dds-sensor-proxy.cpp

@@ -497,7 +497,7 @@ void dds_sensor_proxy::start( rs2_frame_callback_sptr callback )
                         add_frame_metadata( static_cast< frame * >( fh.get() ), *md, streaming );
                     LOG_INFO( dds_stream->name() << " calling invoke_new_frame, last frame number " << streaming.last_frame_number );
                     invoke_new_frame( static_cast< frame * >( fh.release() ), nullptr, nullptr );
-                    LOG_INFO( dds_stream->name() << "invoke_new_frame returned, last frame number " << streaming.last_frame_number );
+                    LOG_INFO( dds_stream->name() << " invoke_new_frame returned, last frame number " << streaming.last_frame_number );
                 }
             } );
         streaming.syncer.start();
@@ -537,8 +537,6 @@ void dds_sensor_proxy::start( rs2_frame_callback_sptr callback )
 
 void dds_sensor_proxy::stop()
 {
-    _is_streaming = false; // Don't handle new frames
-
     for( auto & profile : sensor_base::get_active_streams() )
     {
         auto streamit = _streams.find( sid_index( profile->get_unique_id(), profile->get_stream_index() ) );

third-party/realdds/include/realdds/dds-metadata-syncer.h

@@ -8,6 +8,7 @@
 #include <memory>
 #include <mutex>
 #include <functional>
+#include <atomic>
 
 
 namespace realdds {
@@ -83,7 +84,7 @@ class dds_metadata_syncer
     void enqueue_metadata( key_type, metadata_type const & );
 
     void on_frame_release( on_frame_release_callback cb ) { _on_frame_release = cb; }
-    void on_frame_ready( on_frame_ready_callback cb ) { _on_frame_ready = cb; }
+    void on_frame_ready( on_frame_ready_callback cb );
     void on_metadata_dropped( on_metadata_dropped_callback cb ) { _on_metadata_dropped = cb; }
 
     // Helper to create frame_holder
@@ -104,6 +105,7 @@ class dds_metadata_syncer
     bool drop_metadata( std::unique_lock< std::mutex > & );
 
     std::atomic< bool > _started;
+    std::mutex _frame_ready_mutex;
 };
 
 

third-party/realdds/src/dds-metadata-syncer.cpp

@@ -80,6 +80,11 @@ void dds_metadata_syncer::enqueue_metadata( key_type id, metadata_type const & m
     search_for_match( lock );
 }
 
+void dds_metadata_syncer::on_frame_ready( on_frame_ready_callback cb )
+{
+    std::lock_guard< std::mutex > lock( _frame_ready_mutex );
+    _on_frame_ready = cb;
+}
 
 void dds_metadata_syncer::search_for_match( std::unique_lock< std::mutex > & lock )
 {
@@ -122,7 +127,8 @@ bool dds_metadata_syncer::handle_match( std::unique_lock< std::mutex > & lock )
     _metadata_queue.pop_front();
     _frame_queue.pop_front();
 
-    if( _on_frame_ready && _started)
+    std::lock_guard< std::mutex > lock( _frame_ready_mutex );
+    if( _on_frame_ready )
     {
         LOG_INFO( "dds_metadata_syncer::handle_match opening lock" );
         lock.unlock();
@@ -150,7 +156,8 @@ bool dds_metadata_syncer::handle_frame_without_metadata( std::unique_lock< std::
     frame_holder fh = std::move( _frame_queue.front().second );
     _frame_queue.pop_front();
 
-    if( _on_frame_ready && _started )
+    std::lock_guard< std::mutex > lock( _frame_ready_mutex );
+    if( _on_frame_ready )
     {
         LOG_INFO( "dds_metadata_syncer::handle_frame_without_metadata opening lock" );
         lock.unlock();