X300: Fix for recv timeout and wait_for_ack errors over PCIe.

- Reduced allocation of buffers for each control stream.
- Copied contol data into new managed buffer so managed buffer
  of base transport could be released.

1 files changed, 59 insertions, 9 deletions

diff --git a/host/lib/transport/muxed_zero_copy_if.cpp b/host/lib/transport/muxed_zero_copy_if.cpp
index 996db3c98..7a2b76165 100644
--- a/host/lib/transport/muxed_zero_copy_if.cpp
+++ b/host/lib/transport/muxed_zero_copy_if.cpp
@@ -74,7 +74,12 @@ public:
         if (_streams.size() >= _max_num_streams) {
             throw uhd::runtime_error("muxed_zero_copy_if: stream capacity exceeded. cannot create more streams.");
         }
-        stream_impl::sptr stream = boost::make_shared<stream_impl>(this->shared_from_this(), stream_num);
+        // Only allocate a portion of the base transport's frames to each stream
+        // to prevent all streams from attempting to use all the frames.
+        stream_impl::sptr stream = boost::make_shared<stream_impl>(
+            this->shared_from_this(), stream_num,
+            _base_xport->get_num_send_frames() / _max_num_streams,
+            _base_xport->get_num_recv_frames() / _max_num_streams);
         _streams[stream_num] = stream;
         return stream;
     }
@@ -91,16 +96,55 @@ public:
     }
 
 private:
+    /*
+     * @class stream_mrb is used to copy the data and release the original
+     * managed receive buffer back to the base transport.
+     */
+    class stream_mrb : public managed_recv_buffer
+    {
+    public:
+        stream_mrb(size_t size) : _buff(new char[size]) {}
+
+        ~stream_mrb() {
+            delete _buff;
+        }
+
+        void release() {}
+
+        UHD_INLINE sptr get_new(char *buff, size_t len)
+        {
+            memcpy(_buff, buff, len);
+            return make(this, _buff, len);
+        }
+
+    private:
+        char		*_buff;
+    };
+
     class stream_impl : public zero_copy_if
     {
     public:
         typedef boost::shared_ptr<stream_impl> sptr;
         typedef boost::weak_ptr<stream_impl> wptr;
 
-        stream_impl(muxed_zero_copy_if_impl::sptr muxed_xport, const uint32_t stream_num):
+        stream_impl(
+            muxed_zero_copy_if_impl::sptr muxed_xport,
+            const uint32_t stream_num,
+            const size_t num_send_frames,
+            const size_t num_recv_frames
+            ) :
             _stream_num(stream_num), _muxed_xport(muxed_xport),
-            _buff_queue(muxed_xport->base_xport()->get_num_recv_frames())
+            _num_send_frames(num_send_frames),
+            _send_frame_size(_muxed_xport->base_xport()->get_send_frame_size()),
+            _num_recv_frames(num_recv_frames),
+            _recv_frame_size(_muxed_xport->base_xport()->get_recv_frame_size()),
+            _buff_queue(num_recv_frames),
+            _buffers(num_recv_frames),
+            _buffer_index(0)
         {
+            for (size_t i = 0; i < num_recv_frames; i++) {
+                _buffers[i] = boost::make_shared<stream_mrb>(_recv_frame_size);
+            }
         }
 
         ~stream_impl(void)
@@ -116,11 +160,11 @@ private:
         }
 
         size_t get_num_recv_frames(void) const {
-            return _muxed_xport->base_xport()->get_num_recv_frames();
+            return _num_recv_frames;
         }
 
         size_t get_recv_frame_size(void) const {
-            return _muxed_xport->base_xport()->get_recv_frame_size();
+            return _recv_frame_size;
         }
 
         managed_recv_buffer::sptr get_recv_buff(double timeout) {
@@ -130,19 +174,19 @@ private:
             } else {
                 return managed_recv_buffer::sptr();
             }
-
         }
 
         void push_recv_buff(managed_recv_buffer::sptr buff) {
-            _buff_queue.push_with_wait(buff);
+            _buff_queue.push_with_wait(_buffers.at(_buffer_index++)->get_new(buff->cast<char*>(), buff->size()));
+            _buffer_index %= _buffers.size();
         }
 
         size_t get_num_send_frames(void) const {
-            return _muxed_xport->base_xport()->get_num_send_frames();
+            return _num_send_frames;
         }
 
         size_t get_send_frame_size(void) const {
-            return _muxed_xport->base_xport()->get_send_frame_size();
+            return _send_frame_size;
         }
 
         managed_send_buffer::sptr get_send_buff(double timeout)
@@ -153,7 +197,13 @@ private:
     private:
         const uint32_t                              _stream_num;
         muxed_zero_copy_if_impl::sptr               _muxed_xport;
+        const size_t                                _num_send_frames;
+        const size_t                                _send_frame_size;
+        const size_t                                _num_recv_frames;
+        const size_t                                _recv_frame_size;
         bounded_buffer<managed_recv_buffer::sptr>   _buff_queue;
+        std::vector< boost::shared_ptr<stream_mrb> >    _buffers;
+        size_t                                      _buffer_index;
     };
 
     inline zero_copy_if::sptr& base_xport() { return _base_xport; }