rfnoc: Fix transport buffer reservations

Change transports to reserve the number of frame buffers they actually
need from the I/O service. Previously some I/O service clients reserved
0 buffers since they shared frame buffers with other clients, as we know
the two clients do not use the links simultaneously. This is possible
with the inline_io_service but not with a multithreaded I/O service
which queues buffer for clients before they are requested.

2 files changed, 11 insertions, 9 deletions

diff --git a/host/lib/include/uhdlib/rfnoc/chdr_ctrl_xport.hpp b/host/lib/include/uhdlib/rfnoc/chdr_ctrl_xport.hpp
index 726ea7f6c..2a37a5afc 100644
--- a/host/lib/include/uhdlib/rfnoc/chdr_ctrl_xport.hpp
+++ b/host/lib/include/uhdlib/rfnoc/chdr_ctrl_xport.hpp
@@ -120,6 +120,13 @@ public:
     void release_recv_buff(frame_buff::uptr buff);
 
     /*!
+     * Release a frame buffer, allowing the recv link driver to reuse it.
+     *
+     * \param buffer frame buffer to release for reuse by the link
+     */
+    void release_mgmt_buff(frame_buff::uptr buff);
+
+    /*!
      * Get this xport's EPID
      *
      * \return the source EPID for this transport
diff --git a/host/lib/include/uhdlib/transport/inline_io_service.hpp b/host/lib/include/uhdlib/transport/inline_io_service.hpp
index f10e7018d..f207d15a0 100644
--- a/host/lib/include/uhdlib/transport/inline_io_service.hpp
+++ b/host/lib/include/uhdlib/transport/inline_io_service.hpp
@@ -71,9 +71,8 @@ private:
      * Disconnect the sender and free resources
      *
      * \param link the link that was used for sending data
-     * \param num_frames number of frames to release (same as reservation)
      */
-    void disconnect_sender(send_link_if* link, size_t num_frames);
+    void disconnect_sender(send_link_if* link);
 
     /*!
      * Connect a receiver to the link and reserve resources
@@ -87,9 +86,8 @@ private:
      * Disconnect the receiver from the provided link and free resources
      * \param link the recv link that was used for reception
      * \param cb the callback to disassociate
-     * \param num_frames the number of frames that was reserved for the cb
      */
-    void disconnect_receiver(recv_link_if* link, inline_recv_cb* cb, size_t num_frames);
+    void disconnect_receiver(recv_link_if* link, inline_recv_cb* cb);
 
     /*
      * Function to perform recv operations on a link, which is potentially
@@ -103,14 +101,11 @@ private:
     frame_buff::uptr recv(
         inline_recv_cb* recv_io_cb, recv_link_if* recv_link, int32_t timeout_ms);
 
-    /* Track whether link is muxed, the callback, and buffer reservations */
+    /* Track whether link is muxed and the callback */
     std::unordered_map<recv_link_if*,
-        std::tuple<inline_recv_mux*, inline_recv_cb*, size_t>>
+        std::tuple<inline_recv_mux*, inline_recv_cb*>>
         _recv_tbl;
 
-    /* Track how many send_frames have been reserved for each link */
-    std::unordered_map<send_link_if*, size_t> _send_tbl;
-
     /* Shared ptr kept to avoid untimely release */
     std::list<send_link_if::sptr> _send_links;
     std::list<recv_link_if::sptr> _recv_links;