From 10174fd5306fa62ef442a5941e32078102af3786 Mon Sep 17 00:00:00 2001
From: Eran <librealsense.eran@gmail.com>
Date: Thu, 16 Mar 2023 09:09:43 +0200
Subject: [PATCH] add dds-topic-reader::stop()

---
 .../include/realdds/dds-topic-reader-thread.h |  3 +++
 .../include/realdds/dds-topic-reader.h        |  3 +++
 .../realdds/src/dds-topic-reader-thread.cpp   | 26 ++++++++++++++++++-
 third-party/realdds/src/dds-topic-reader.cpp  | 14 ++++++++++
 4 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/third-party/realdds/include/realdds/dds-topic-reader-thread.h b/third-party/realdds/include/realdds/dds-topic-reader-thread.h
index 064e9f4e13..b5efc89b10 100644
--- a/third-party/realdds/include/realdds/dds-topic-reader-thread.h
+++ b/third-party/realdds/include/realdds/dds-topic-reader-thread.h
@@ -33,10 +33,13 @@ class dds_topic_reader_thread : public dds_topic_reader
     typedef dds_topic_reader super;
 
 public:
+    dds_topic_reader_thread( std::shared_ptr< dds_topic > const & topic );
     dds_topic_reader_thread( std::shared_ptr< dds_topic > const & topic,
                              std::shared_ptr< dds_subscriber > const & subscriber );
+    ~dds_topic_reader_thread();
 
     void run( qos const & ) override;
+    void stop() override;
 };
 
 
diff --git a/third-party/realdds/include/realdds/dds-topic-reader.h b/third-party/realdds/include/realdds/dds-topic-reader.h
index d2e6a61291..d46838e963 100644
--- a/third-party/realdds/include/realdds/dds-topic-reader.h
+++ b/third-party/realdds/include/realdds/dds-topic-reader.h
@@ -75,6 +75,9 @@ class dds_topic_reader : public eprosima::fastdds::dds::DataReaderListener
     // The callbacks should be set before we actually create the underlying DDS objects, so the reader does not
     virtual void run( qos const & );
 
+    // Go back to a pre-run() state, such that is_running() returns false
+    virtual void stop();
+
     // DataReaderListener
 protected:
     void on_subscription_matched( eprosima::fastdds::dds::DataReader *,
diff --git a/third-party/realdds/src/dds-topic-reader-thread.cpp b/third-party/realdds/src/dds-topic-reader-thread.cpp
index 6ea4f6b1f2..b9bcc727b8 100644
--- a/third-party/realdds/src/dds-topic-reader-thread.cpp
+++ b/third-party/realdds/src/dds-topic-reader-thread.cpp
@@ -14,22 +14,39 @@
 namespace realdds {
 
 
+dds_topic_reader_thread::dds_topic_reader_thread( std::shared_ptr< dds_topic > const & topic )
+    : dds_topic_reader_thread( topic, std::make_shared< dds_subscriber >( topic->get_participant() ) )
+{
+}
+
+
 dds_topic_reader_thread::dds_topic_reader_thread( std::shared_ptr< dds_topic > const & topic,
                                                   std::shared_ptr< dds_subscriber > const & subscriber )
     : super( topic, subscriber )
     , _th(
-          [this]( dispatcher::cancellable_timer )
+          [this, name = topic->get()->get_name()]( dispatcher::cancellable_timer )
           {
               if( ! _reader )
                   return;
               eprosima::fastrtps::Duration_t const one_second = { 1, 0 };
+              LOG_DEBUG( "----> '" << name << "' waiting for message" );
               if( _reader->wait_for_unread_message( one_second ) )
+              {
+                  LOG_DEBUG( "----> '" << name << "' callback" );
                   _on_data_available();
+                  LOG_DEBUG( "<---- '" << name << "' callback" );
+              }
           } )
 {
 }
 
 
+dds_topic_reader_thread::~dds_topic_reader_thread()
+{
+    LOG_DEBUG( "xxxxx '" << ( _reader ? _reader->get_topicdescription()->get_name() : "unknown" ) << "' dtor" );
+}
+
+
 void dds_topic_reader_thread::run( qos const & rqos )
 {
     if( ! _on_data_available )
@@ -43,4 +60,11 @@ void dds_topic_reader_thread::run( qos const & rqos )
 }
 
 
+void dds_topic_reader_thread::stop()
+{
+    _th.stop();
+    super::stop();
+}
+
+
 }  // namespace realdds
diff --git a/third-party/realdds/src/dds-topic-reader.cpp b/third-party/realdds/src/dds-topic-reader.cpp
index 1733ff1bb5..f011c40e8f 100644
--- a/third-party/realdds/src/dds-topic-reader.cpp
+++ b/third-party/realdds/src/dds-topic-reader.cpp
@@ -94,6 +94,20 @@ void dds_topic_reader::run( qos const & rqos )
 }
 
 
+void dds_topic_reader::stop()
+{
+    if( _subscriber )
+    {
+        if( _reader )
+        {
+            DDS_API_CALL_NO_THROW( _subscriber->get()->delete_datareader( _reader ) );
+            _reader = nullptr;
+        }
+    }
+    assert( ! is_running() );
+}
+
+
 void dds_topic_reader::on_subscription_matched(
     eprosima::fastdds::dds::DataReader *, eprosima::fastdds::dds::SubscriptionMatchedStatus const & info )
 {