rfnoc: Resolves streamer/link segfaults on python

This commit resolves a segfault that occurs during teardown. Since
teardown isn't detereministic in python, there were cases where the
graph would destruct before the streamers or links got chance to
cleanup. This would result in a segfault. This change gives the lambda
a shared pointer to the object the callback method is calling on, so
that it won't destruct before being called.

4 files changed, 33 insertions, 24 deletions

diff --git a/host/include/uhd/rfnoc_graph.hpp b/host/include/uhd/rfnoc_graph.hpp
index fabee53c7..e51fc3d83 100644
--- a/host/include/uhd/rfnoc_graph.hpp
+++ b/host/include/uhd/rfnoc_graph.hpp
@@ -29,7 +29,7 @@ class mb_controller;
  * session, but also manages the RFNoC blocks on those devices. Only devices
  * compatible with a modern version of RFNoC can be addressed by this class.
  */
-class UHD_API rfnoc_graph : public uhd::noncopyable
+class UHD_API rfnoc_graph : public uhd::noncopyable, public std::enable_shared_from_this<rfnoc_graph>
 {
 public:
     /*! A shared pointer to allow easy access to this class and for
diff --git a/host/lib/rfnoc/rfnoc_graph.cpp b/host/lib/rfnoc/rfnoc_graph.cpp
index 027d27f81..2e90fb48f 100644
--- a/host/lib/rfnoc/rfnoc_graph.cpp
+++ b/host/lib/rfnoc/rfnoc_graph.cpp
@@ -442,15 +442,17 @@ public:
     uhd::rx_streamer::sptr create_rx_streamer(
         const size_t num_ports, const uhd::stream_args_t& args)
     {
+        auto this_graph = shared_from_this();
         return std::make_shared<rfnoc_rx_streamer>(
-            num_ports, args, [this](const std::string& id) { this->disconnect(id); });
+            num_ports, args, [this_graph](const std::string& id) { this_graph->disconnect(id); });
     }
 
     uhd::tx_streamer::sptr create_tx_streamer(
         const size_t num_ports, const uhd::stream_args_t& args)
     {
+        auto this_graph = shared_from_this();
         return std::make_shared<rfnoc_tx_streamer>(
-            num_ports, args, [this](const std::string& id) { this->disconnect(id); });
+            num_ports, args, [this_graph](const std::string& id) { this_graph->disconnect(id); });
     }
 
     size_t get_num_mboards() const
diff --git a/host/lib/usrp/mpmd/mpmd_mb_iface.cpp b/host/lib/usrp/mpmd/mpmd_mb_iface.cpp
index 534d71a4d..a24be5c57 100644
--- a/host/lib/usrp/mpmd/mpmd_mb_iface.cpp
+++ b/host/lib/usrp/mpmd/mpmd_mb_iface.cpp
@@ -176,6 +176,7 @@ uhd::rfnoc::chdr_ctrl_xport::sptr mpmd_mboard_impl::mpmd_mb_iface::make_ctrl_tra
         recv_link, send_link, transport::link_type_t::CTRL);
 
     auto pkt_factory = _link_if_mgr->get_packet_factory(link_idx);
+    auto io_srv_mgr = this->get_io_srv_mgr();
     auto xport       = uhd::rfnoc::chdr_ctrl_xport::make(io_srv,
         send_link,
         recv_link,
@@ -183,8 +184,8 @@ uhd::rfnoc::chdr_ctrl_xport::sptr mpmd_mboard_impl::mpmd_mb_iface::make_ctrl_tra
         local_epid,
         send_link->get_num_send_frames(),
         recv_link->get_num_recv_frames(),
-        [this, send_link, recv_link]() {
-            this->get_io_srv_mgr()->disconnect_links(recv_link, send_link);
+        [io_srv_mgr, send_link, recv_link]() {
+            io_srv_mgr->disconnect_links(recv_link, send_link);
         });
     return xport;
 }
@@ -242,6 +243,7 @@ mpmd_mboard_impl::mpmd_mb_iface::make_rx_data_transport(
 
     // Create the data transport
     auto pkt_factory = _link_if_mgr->get_packet_factory(link_idx);
+    auto io_srv_mgr = this->get_io_srv_mgr();
     auto fc_params   = chdr_rx_data_xport::configure_sep(cfg_io_srv,
         recv_link,
         send_link,
@@ -254,8 +256,8 @@ mpmd_mboard_impl::mpmd_mb_iface::make_rx_data_transport(
         fc_freq,
         fc_headroom,
         lossy_xport,
-        [this, recv_link, send_link]() {
-            this->get_io_srv_mgr()->disconnect_links(recv_link, send_link);
+        [io_srv_mgr, recv_link, send_link]() {
+            io_srv_mgr->disconnect_links(recv_link, send_link);
         });
 
     cfg_io_srv.reset();
@@ -275,8 +277,8 @@ mpmd_mboard_impl::mpmd_mb_iface::make_rx_data_transport(
         epids,
         recv_link->get_num_recv_frames(),
         fc_params,
-        [this, recv_link, send_link]() {
-            this->get_io_srv_mgr()->disconnect_links(recv_link, send_link);
+        [io_srv_mgr, recv_link, send_link]() {
+            io_srv_mgr->disconnect_links(recv_link, send_link);
         });
 
     return rx_xport;
@@ -319,6 +321,7 @@ mpmd_mboard_impl::mpmd_mb_iface::make_tx_data_transport(
         recv_link, send_link, transport::link_type_t::CTRL);
 
     auto pkt_factory         = _link_if_mgr->get_packet_factory(link_idx);
+    auto io_srv_mgr = this->get_io_srv_mgr();
     const auto buff_capacity = chdr_tx_data_xport::configure_sep(cfg_io_srv,
         recv_link,
         send_link,
@@ -329,8 +332,8 @@ mpmd_mboard_impl::mpmd_mb_iface::make_tx_data_transport(
         mdata_buff_fmt,
         fc_freq_ratio,
         fc_headroom_ratio,
-        [this, recv_link, send_link]() {
-            this->get_io_srv_mgr()->disconnect_links(recv_link, send_link);
+        [io_srv_mgr, recv_link, send_link]() {
+            io_srv_mgr->disconnect_links(recv_link, send_link);
         });
 
     cfg_io_srv.reset();
@@ -351,8 +354,8 @@ mpmd_mboard_impl::mpmd_mb_iface::make_tx_data_transport(
         epids,
         send_link->get_num_send_frames(),
         buff_capacity,
-        [this, recv_link, send_link]() {
-            this->get_io_srv_mgr()->disconnect_links(recv_link, send_link);
+        [io_srv_mgr, recv_link, send_link]() {
+            io_srv_mgr->disconnect_links(recv_link, send_link);
         });
 
     return tx_xport;
diff --git a/host/lib/usrp/x300/x300_mb_iface.cpp b/host/lib/usrp/x300/x300_mb_iface.cpp
index a6d5e794b..c89374f82 100644
--- a/host/lib/usrp/x300/x300_mb_iface.cpp
+++ b/host/lib/usrp/x300/x300_mb_iface.cpp
@@ -110,7 +110,7 @@ uhd::rfnoc::chdr_ctrl_xport::sptr x300_impl::x300_mb_iface::make_ctrl_transport(
 
     auto io_srv =
         get_io_srv_mgr()->connect_links(recv_link, send_link, link_type_t::CTRL);
-
+    auto io_srv_mgr = this->get_io_srv_mgr();
     auto xport = chdr_ctrl_xport::make(io_srv,
         send_link,
         recv_link,
@@ -118,8 +118,8 @@ uhd::rfnoc::chdr_ctrl_xport::sptr x300_impl::x300_mb_iface::make_ctrl_transport(
         local_epid,
         send_link->get_num_send_frames(),
         recv_link->get_num_recv_frames(),
-        [this, send_link, recv_link]() {
-            this->get_io_srv_mgr()->disconnect_links(recv_link, send_link);
+        [io_srv_mgr, send_link, recv_link]() {
+            io_srv_mgr->disconnect_links(recv_link, send_link);
         });
     return xport;
 }
@@ -174,6 +174,8 @@ uhd::rfnoc::chdr_rx_data_xport::uptr x300_impl::x300_mb_iface::make_rx_data_tran
     auto cfg_io_srv =
         get_io_srv_mgr()->connect_links(recv_link, send_link, link_type_t::CTRL);
 
+    auto io_srv_mgr = this->get_io_srv_mgr();
+
     auto fc_params = uhd::rfnoc::chdr_rx_data_xport::configure_sep(cfg_io_srv,
         recv_link,
         send_link,
@@ -186,8 +188,8 @@ uhd::rfnoc::chdr_rx_data_xport::uptr x300_impl::x300_mb_iface::make_rx_data_tran
         fc_freq,
         fc_headroom,
         lossy_xport,
-        [this, recv_link, send_link]() {
-            this->get_io_srv_mgr()->disconnect_links(recv_link, send_link);
+        [io_srv_mgr, recv_link, send_link]() {
+            io_srv_mgr->disconnect_links(recv_link, send_link);
         });
 
     cfg_io_srv.reset();
@@ -208,8 +210,8 @@ uhd::rfnoc::chdr_rx_data_xport::uptr x300_impl::x300_mb_iface::make_rx_data_tran
         epids,
         recv_link->get_num_recv_frames(),
         fc_params,
-        [this, recv_link, send_link]() {
-            this->get_io_srv_mgr()->disconnect_links(recv_link, send_link);
+        [io_srv_mgr, recv_link, send_link]() {
+            io_srv_mgr->disconnect_links(recv_link, send_link);
         });
 
     return rx_xport;
@@ -250,6 +252,8 @@ uhd::rfnoc::chdr_tx_data_xport::uptr x300_impl::x300_mb_iface::make_tx_data_tran
     auto cfg_io_srv =
         get_io_srv_mgr()->connect_links(recv_link, send_link, link_type_t::CTRL);
 
+    auto io_srv_mgr = this->get_io_srv_mgr();
+
     const auto buff_capacity = chdr_tx_data_xport::configure_sep(cfg_io_srv,
         recv_link,
         send_link,
@@ -260,8 +264,8 @@ uhd::rfnoc::chdr_tx_data_xport::uptr x300_impl::x300_mb_iface::make_tx_data_tran
         mdata_buff_fmt,
         fc_freq_ratio,
         fc_headroom_ratio,
-        [this, recv_link, send_link]() {
-            this->get_io_srv_mgr()->disconnect_links(recv_link, send_link);
+        [io_srv_mgr, recv_link, send_link]() {
+            io_srv_mgr->disconnect_links(recv_link, send_link);
         });
 
     cfg_io_srv.reset();
@@ -282,8 +286,8 @@ uhd::rfnoc::chdr_tx_data_xport::uptr x300_impl::x300_mb_iface::make_tx_data_tran
         epids,
         send_link->get_num_send_frames(),
         buff_capacity,
-        [this, recv_link, send_link]() {
-            this->get_io_srv_mgr()->disconnect_links(recv_link, send_link);
+        [io_srv_mgr, recv_link, send_link]() {
+            io_srv_mgr->disconnect_links(recv_link, send_link);
         });
 
     return tx_xport;