Created inline send vrt packer function that also handles fragmentation.

6 files changed, 232 insertions, 124 deletions

diff --git a/host/include/uhd/device.hpp b/host/include/uhd/device.hpp
index ae75e6dc8..ecbe8c95c 100644
--- a/host/include/uhd/device.hpp
+++ b/host/include/uhd/device.hpp
@@ -80,12 +80,11 @@ public:
      * Send a buffer containing IF data with its metadata.
      *
      * Send handles fragmentation as follows:
-     * If the buffer has more samples than the maximum supported,
-     * the send method will send the maximum number of samples
-     * as supported by the transport and return the number sent.
-     * In this case, the end of burst flag will be forced to false.
-     * It is up to the caller to call send again on the un-sent
-     * portions of the buffer, until the buffer is exhausted.
+     * If the buffer has more samples than the maximum per packet,
+     * the send method will fragment the samples across several packets.
+     * Send will respect the burst flags when fragmenting to ensure
+     * that start of burst can only be set on the first fragment and
+     * that end of burst can only be set on the final fragment.
      *
      * This is a blocking call and will not return until the number
      * of samples returned have been read out of the buffer.
diff --git a/host/include/uhd/types/otw_type.hpp b/host/include/uhd/types/otw_type.hpp
index f10664584..8e3e65d78 100644
--- a/host/include/uhd/types/otw_type.hpp
+++ b/host/include/uhd/types/otw_type.hpp
@@ -55,6 +55,12 @@ namespace uhd{
             BO_NOT_APPLICABLE = '|'
         } byteorder;
 
+        /*!
+         * Get the sample size of this otw type.
+         * \return the size of a sample in bytes
+         */
+        size_t get_sample_size(void) const;
+
         otw_type_t(void);
     };
 
diff --git a/host/lib/transport/vrt_packet_handler.hpp b/host/lib/transport/vrt_packet_handler.hpp
index a6161ef55..cd0c89b05 100644
--- a/host/lib/transport/vrt_packet_handler.hpp
+++ b/host/lib/transport/vrt_packet_handler.hpp
@@ -57,6 +57,49 @@ namespace vrt_packet_handler{
         /* NOP */
     }
 
+    /*******************************************************************
+     * Unpack a received vrt header and set the copy buffer.
+     *  - helper function for vrt_packet_handler::recv
+     ******************************************************************/
+    static inline void _recv_helper(
+        recv_state &state,
+        uhd::rx_metadata_t &metadata,
+        double tick_rate,
+        size_t vrt_header_offset_words32
+    ){
+        size_t num_packet_words32 = state.managed_buff->size()/sizeof(boost::uint32_t);
+        if (num_packet_words32 <= vrt_header_offset_words32){
+            state.copy_buff = boost::asio::buffer("", 0);
+            return; //must exit here after setting the buffer
+        }
+        const boost::uint32_t *vrt_hdr = state.managed_buff->cast<const boost::uint32_t *>() + vrt_header_offset_words32;
+        size_t num_header_words32_out, num_payload_words32_out, packet_count_out;
+        uhd::transport::vrt::unpack(
+            metadata,                //output
+            vrt_hdr,                 //input
+            num_header_words32_out,  //output
+            num_payload_words32_out, //output
+            num_packet_words32,      //input
+            packet_count_out,        //output
+            tick_rate
+        );
+
+        //handle the packet count / sequence number
+        if (packet_count_out != state.next_packet_seq){
+            std::cerr << "S" << (packet_count_out - state.next_packet_seq)%16;
+        }
+        state.next_packet_seq = (packet_count_out+1)%16;
+
+        //setup the buffer to point to the data
+        state.copy_buff = boost::asio::buffer(
+            vrt_hdr + num_header_words32_out,
+            num_payload_words32_out*sizeof(boost::uint32_t)
+        );
+    }
+
+    /*******************************************************************
+     * Recv vrt packets and copy convert the samples into the buffer.
+     ******************************************************************/
     static inline size_t recv(
         recv_state &state,
         const boost::asio::mutable_buffer &buff,
@@ -65,95 +108,184 @@ namespace vrt_packet_handler{
         const uhd::otw_type_t &otw_type,
         double tick_rate,
         uhd::transport::zero_copy_if::sptr zc_iface,
+        //use these two params to handle a layer above vrt
         size_t vrt_header_offset_words32 = 0,
         const recv_cb_t& recv_cb = &recv_cb_nop
     ){
-        ////////////////////////////////////////////////////////////////
-        // Perform the recv
-        ////////////////////////////////////////////////////////////////
-        {
-            //perform a receive if no rx data is waiting to be copied
-            if (boost::asio::buffer_size(state.copy_buff) == 0){
-                state.fragment_offset_in_samps = 0;
-                state.managed_buff = zc_iface->get_recv_buff();
-                recv_cb(state.managed_buff);
-            }
-            //otherwise flag the metadata to show that is is a fragment
-            else{
-                metadata = uhd::rx_metadata_t();
-                goto vrt_recv_copy_convert;
-            }
-        }
+        metadata = uhd::rx_metadata_t(); //init the metadata
 
-        ////////////////////////////////////////////////////////////////
-        // Unpack the vrt header
-        ////////////////////////////////////////////////////////////////
-        {
-            size_t num_packet_words32 = state.managed_buff->size()/sizeof(boost::uint32_t);
-            if (num_packet_words32 <= vrt_header_offset_words32){
-                state.copy_buff = boost::asio::buffer("", 0);
-                goto vrt_recv_copy_convert; //must exit here after setting the buffer
-            }
-            const boost::uint32_t *vrt_hdr = state.managed_buff->cast<const boost::uint32_t *>() + vrt_header_offset_words32;
-            size_t num_header_words32_out, num_payload_words32_out, packet_count_out;
-            uhd::transport::vrt::unpack(
-                metadata,                //output
-                vrt_hdr,                 //input
-                num_header_words32_out,  //output
-                num_payload_words32_out, //output
-                num_packet_words32,      //input
-                packet_count_out,        //output
-                tick_rate
+        //perform a receive if no rx data is waiting to be copied
+        if (boost::asio::buffer_size(state.copy_buff) == 0){
+            state.fragment_offset_in_samps = 0;
+            state.managed_buff = zc_iface->get_recv_buff();
+            recv_cb(state.managed_buff); //callback before vrt unpack
+            _recv_helper(
+                state, metadata, tick_rate, vrt_header_offset_words32
             );
+        }
 
-            //handle the packet count / sequence number
-            if (packet_count_out != state.next_packet_seq){
-                std::cerr << "S" << (packet_count_out - state.next_packet_seq)%16;
-            }
-            state.next_packet_seq = (packet_count_out+1)%16;
+        //extract the number of samples available to copy
+        size_t bytes_per_item = otw_type.get_sample_size();
+        size_t bytes_available = boost::asio::buffer_size(state.copy_buff);
+        size_t num_samps = std::min(
+            boost::asio::buffer_size(buff)/io_type.size,
+            bytes_available/bytes_per_item
+        );
 
-            //setup the buffer to point to the data
-            state.copy_buff = boost::asio::buffer(
-                vrt_hdr + num_header_words32_out,
-                num_payload_words32_out*sizeof(boost::uint32_t)
-            );
+        //setup the fragment flags and offset
+        metadata.more_fragments = boost::asio::buffer_size(buff)/io_type.size < num_samps;
+        metadata.fragment_offset = state.fragment_offset_in_samps;
+        state.fragment_offset_in_samps += num_samps; //set for next call
+
+        //copy-convert the samples from the recv buffer
+        uhd::transport::convert_otw_type_to_io_type(
+            boost::asio::buffer_cast<const void*>(state.copy_buff), otw_type,
+            boost::asio::buffer_cast<void*>(buff), io_type,
+            num_samps
+        );
+
+        //update the rx copy buffer to reflect the bytes copied
+        size_t bytes_copied = num_samps*bytes_per_item;
+        state.copy_buff = boost::asio::buffer(
+            boost::asio::buffer_cast<const boost::uint8_t*>(state.copy_buff) + bytes_copied,
+            bytes_available - bytes_copied
+        );
+
+        return num_samps;
+    }
+
+/***********************************************************************
+ * vrt packet handler for send
+ **********************************************************************/
+    struct send_state{
+        //init the expected seq number
+        size_t next_packet_seq;
+
+        send_state(void){
+            next_packet_seq = 0;
         }
+    };
 
-        ////////////////////////////////////////////////////////////////
-        // Perform copy-convert into buffer
-        ////////////////////////////////////////////////////////////////
-        vrt_recv_copy_convert:{
-            size_t bytes_per_item = (otw_type.width * 2) / 8;
-
-            //extract the number of samples available to copy
-            //and a pointer into the usrp2 received items memory
-            size_t bytes_available = boost::asio::buffer_size(state.copy_buff);
-            size_t num_samps = std::min(
-                boost::asio::buffer_size(buff)/io_type.size,
-                bytes_available/bytes_per_item
-            );
+    typedef boost::function<void(uhd::transport::managed_send_buffer::sptr)> send_cb_t;
 
-            //setup the fragment flags and offset
-            metadata.more_fragments = boost::asio::buffer_size(buff)/io_type.size < num_samps;
-            metadata.fragment_offset = state.fragment_offset_in_samps;
-            state.fragment_offset_in_samps += num_samps; //set for next time
+    static inline void send_cb_nop(uhd::transport::managed_send_buffer::sptr){
+        /* NOP */
+    }
 
-            //copy-convert the samples from the recv buffer
-            uhd::transport::convert_otw_type_to_io_type(
-                boost::asio::buffer_cast<const void*>(state.copy_buff), otw_type,
-                boost::asio::buffer_cast<void*>(buff), io_type,
-                num_samps
-            );
+    /*******************************************************************
+     * Pack a vrt header, copy-convert the data, and send it.
+     *  - helper function for vrt_packet_handler::send
+     ******************************************************************/
+    static inline void _send_helper(
+        send_state &state,
+        const void *send_mem,
+        size_t num_samps,
+        const uhd::tx_metadata_t &metadata,
+        const uhd::io_type_t &io_type,
+        const uhd::otw_type_t &otw_type,
+        double tick_rate,
+        uhd::transport::zero_copy_if::sptr zc_iface,
+        size_t vrt_header_offset_words32,
+        const send_cb_t& send_cb
+    ){
+        //get a new managed send buffer
+        uhd::transport::managed_send_buffer::sptr send_buff = zc_iface->get_send_buff();
+        boost::uint32_t *tx_mem = send_buff->cast<boost::uint32_t *>() + vrt_header_offset_words32;
+
+        size_t num_header_words32, num_packet_words32;
+        size_t packet_count = state.next_packet_seq++;
 
-            //update the rx copy buffer to reflect the bytes copied
-            size_t bytes_copied = num_samps*bytes_per_item;
-            state.copy_buff = boost::asio::buffer(
-                boost::asio::buffer_cast<const boost::uint8_t*>(state.copy_buff) + bytes_copied,
-                bytes_available - bytes_copied
+        //pack metadata into a vrt header
+        uhd::transport::vrt::pack(
+            metadata,            //input
+            tx_mem,              //output
+            num_header_words32,  //output
+            num_samps,           //input
+            num_packet_words32,  //output
+            packet_count,        //input
+            tick_rate
+        );
+
+        //copy-convert the samples into the send buffer
+        uhd::transport::convert_io_type_to_otw_type(
+            send_mem, io_type,
+            tx_mem + num_header_words32, otw_type,
+            num_samps
+        );
+
+        send_cb(send_buff); //callback after memory filled
+
+        //commit the samples to the zero-copy interface
+        send_buff->done(num_packet_words32*sizeof(boost::uint32_t));
+    }
+
+    /*******************************************************************
+     * Send vrt packets and copy convert the samples into the buffer.
+     ******************************************************************/
+    static inline size_t send(
+        send_state &state,
+        const boost::asio::const_buffer &buff,
+        const uhd::tx_metadata_t &metadata,
+        const uhd::io_type_t &io_type,
+        const uhd::otw_type_t &otw_type,
+        double tick_rate,
+        uhd::transport::zero_copy_if::sptr zc_iface,
+        size_t max_samples_per_packet,
+        //use these two params to handle a layer above vrt
+        size_t vrt_header_offset_words32 = 0,
+        const send_cb_t& send_cb = &send_cb_nop
+    ){
+
+        size_t total_num_samps = boost::asio::buffer_size(buff)/io_type.size;
+
+        //special case: no fragmentation needed
+        if (total_num_samps <= max_samples_per_packet){
+            _send_helper(
+                state,
+                boost::asio::buffer_cast<const void *>(buff),
+                total_num_samps,
+                metadata,
+                io_type, otw_type,
+                tick_rate,
+                zc_iface,
+                vrt_header_offset_words32,
+                send_cb
             );
+            return total_num_samps;
+        }
 
-            return num_samps;
+        //calculate constants for fragmentation
+        const size_t final_packet_samps = total_num_samps%max_samples_per_packet;
+        const size_t num_fragments = (total_num_samps+max_samples_per_packet-1)/max_samples_per_packet;
+        static const size_t first_fragment_index = 0;
+        const size_t final_fragment_index = num_fragments-1;
+
+        //make a rw copy of the metadata to re-flag below
+        uhd::tx_metadata_t md(metadata);
+
+        //loop through the following fragment indexes
+        for (size_t n = first_fragment_index; n <= final_fragment_index; n++){
+
+            //calculate new flags for the fragments
+            md.has_time_spec  = md.has_time_spec  and (n == first_fragment_index);
+            md.start_of_burst = md.start_of_burst and (n == first_fragment_index);
+            md.end_of_burst   = md.end_of_burst   and (n == final_fragment_index);
+
+            //send the fragment with the helper function
+            _send_helper(
+                state,
+                boost::asio::buffer_cast<const boost::uint8_t *>(buff) + (n*max_samples_per_packet*io_type.size),
+                (n == final_fragment_index)?final_packet_samps:max_samples_per_packet,
+                md,
+                io_type, otw_type,
+                tick_rate,
+                zc_iface,
+                vrt_header_offset_words32,
+                send_cb
+            );
         }
+
+        return total_num_samps;
     }
 
 } //namespace vrt_packet_handler
diff --git a/host/lib/types.cpp b/host/lib/types.cpp
index 33eb550a1..87a2ad4ab 100644
--- a/host/lib/types.cpp
+++ b/host/lib/types.cpp
@@ -220,6 +220,10 @@ std::string mac_addr_t::to_string(void) const{
 /***********************************************************************
  * otw type
  **********************************************************************/
+size_t otw_type_t::get_sample_size(void) const{
+    return (this->width * 2) / 8;
+}
+
 otw_type_t::otw_type_t(void){
     width = 0;
     shift = 0;
diff --git a/host/lib/usrp/usrp2/io_impl.cpp b/host/lib/usrp/usrp2/io_impl.cpp
index 389460fe8..b26dbb8bd 100644
--- a/host/lib/usrp/usrp2/io_impl.cpp
+++ b/host/lib/usrp/usrp2/io_impl.cpp
@@ -67,49 +67,17 @@ void usrp2_impl::io_init(void){
  **********************************************************************/
 size_t usrp2_impl::send(
     const asio::const_buffer &buff,
-    const tx_metadata_t &metadata_,
+    const tx_metadata_t &metadata,
     const io_type_t &io_type
 ){
-    tx_metadata_t metadata = metadata_; //rw copy to change later
-
-    transport::managed_send_buffer::sptr send_buff = _data_transport->get_send_buff();
-    boost::uint32_t *tx_mem = send_buff->cast<boost::uint32_t *>();
-    size_t num_samps = std::min(std::min(
-        asio::buffer_size(buff)/io_type.size,
-        size_t(max_tx_samps_per_packet())),
-        send_buff->size()/io_type.size
-    );
-
-    //kill the end of burst flag if this is a fragment
-    if (asio::buffer_size(buff)/io_type.size < num_samps)
-        metadata.end_of_burst = false;
-
-    size_t num_header_words32, num_packet_words32;
-    size_t packet_count = _tx_stream_id_to_packet_seq[metadata.stream_id]++;
-
-    //pack metadata into a vrt header
-    vrt::pack(
-        metadata,            //input
-        tx_mem,              //output
-        num_header_words32,  //output
-        num_samps,           //input
-        num_packet_words32,  //output
-        packet_count,        //input
-        get_master_clock_freq()
-    );
-
-    boost::uint32_t *items = tx_mem + num_header_words32; //offset for data
-
-    //copy-convert the samples into the send buffer
-    convert_io_type_to_otw_type(
-        asio::buffer_cast<const void*>(buff), io_type,
-        (void*)items, _tx_otw_type,
-        num_samps
+    return vrt_packet_handler::send(
+        _packet_handler_send_state, //last state of the send handler
+        buff, metadata,             //buffer to empty and samples metadata
+        io_type, _tx_otw_type,      //input and output types to convert
+        get_master_clock_freq(),    //master clock tick rate
+        _data_transport,            //zero copy interface
+        max_tx_samps_per_packet()
     );
-
-    //send and return number of samples
-    send_buff->done(num_packet_words32*sizeof(boost::uint32_t));
-    return num_samps;
 }
 
 /***********************************************************************
diff --git a/host/lib/usrp/usrp2/usrp2_impl.hpp b/host/lib/usrp/usrp2/usrp2_impl.hpp
index 6958fc8ea..f98aa1938 100644
--- a/host/lib/usrp/usrp2/usrp2_impl.hpp
+++ b/host/lib/usrp/usrp2/usrp2_impl.hpp
@@ -122,8 +122,6 @@ private:
     codec_ctrl::sptr _codec_ctrl;
     serdes_ctrl::sptr _serdes_ctrl;
 
-    uhd::dict<boost::uint32_t, size_t> _tx_stream_id_to_packet_seq;
-
     /*******************************************************************
      * Deal with the rx and tx packet sizes
      ******************************************************************/
@@ -139,13 +137,14 @@ private:
         uhd::transport::vrt::max_header_words32*sizeof(boost::uint32_t)
     ;
     size_t max_rx_samps_per_packet(void){
-        return _max_rx_bytes_per_packet/(_rx_otw_type.width*2/8);
+        return _max_rx_bytes_per_packet/_rx_otw_type.get_sample_size();
     }
     size_t max_tx_samps_per_packet(void){
-        return _max_tx_bytes_per_packet/(_tx_otw_type.width*2/8);
+        return _max_tx_bytes_per_packet/_tx_otw_type.get_sample_size();
     }
 
     vrt_packet_handler::recv_state _packet_handler_recv_state;
+    vrt_packet_handler::send_state _packet_handler_send_state;
     uhd::otw_type_t _rx_otw_type, _tx_otw_type;
     void io_init(void);