uhd: ssize_t for phony zero copy return types, null sptr for timeout/error with get managed buffers

5 files changed, 22 insertions, 17 deletions

diff --git a/host/include/uhd/transport/zero_copy.hpp b/host/include/uhd/transport/zero_copy.hpp
index da10bfbe2..513291b63 100644
--- a/host/include/uhd/transport/zero_copy.hpp
+++ b/host/include/uhd/transport/zero_copy.hpp
@@ -82,8 +82,9 @@ namespace uhd{ namespace transport{
          * This should be called to commit the write to the transport object.
          * After calling, the referenced memory should be considered invalid.
          * \param num_bytes the number of bytes written into the buffer
+         * \return the number of bytes written, 0 for timeout, negative for error
          */
-        virtual void commit(size_t num_bytes) = 0;
+        virtual ssize_t commit(size_t num_bytes) = 0;
 
         /*!
          * Get the size of the underlying buffer.
@@ -121,6 +122,7 @@ namespace uhd{ namespace transport{
 
         /*!
          * Get a new receive buffer from this transport object.
+         * \return a managed buffer, or null sptr on timeout/error
          */
         virtual managed_recv_buffer::sptr get_recv_buff(void) = 0;
 
@@ -135,6 +137,7 @@ namespace uhd{ namespace transport{
 
         /*!
          * Get a new send buffer from this transport object.
+         * \return a managed buffer, or null sptr on timeout/error
          */
         virtual managed_send_buffer::sptr get_send_buff(void) = 0;
 
@@ -175,9 +178,9 @@ namespace uhd{ namespace transport{
         /*!
          * Perform a private copying recv.
          * \param buff the buffer to write data into
-         * \return the number of bytes written to buff
+         * \return the number of bytes written to buff, 0 for timeout, negative for error
          */
-        virtual size_t recv(const boost::asio::mutable_buffer &buff) = 0;
+        virtual ssize_t recv(const boost::asio::mutable_buffer &buff) = 0;
 
         UHD_PIMPL_DECL(impl) _impl;
     };
@@ -208,9 +211,9 @@ namespace uhd{ namespace transport{
         /*!
          * Perform a private copying send.
          * \param buff the buffer to read data from
-         * \return the number of bytes read from buff
+         * \return the number of bytes read from buff, 0 for timeout, negative for error
          */
-        virtual size_t send(const boost::asio::const_buffer &buff) = 0;
+        virtual ssize_t send(const boost::asio::const_buffer &buff) = 0;
 
         UHD_PIMPL_DECL(impl) _impl;
     };
diff --git a/host/lib/transport/udp_zero_copy_asio.cpp b/host/lib/transport/udp_zero_copy_asio.cpp
index e3f3ef5bf..98451f188 100644
--- a/host/lib/transport/udp_zero_copy_asio.cpp
+++ b/host/lib/transport/udp_zero_copy_asio.cpp
@@ -105,7 +105,7 @@ private:
     boost::asio::io_service        _io_service;
     int                            _sock_fd;
 
-    size_t recv(const boost::asio::mutable_buffer &buff){
+    ssize_t recv(const boost::asio::mutable_buffer &buff){
         //setup timeval for timeout
         timeval tv;
         tv.tv_sec = 0;
@@ -122,17 +122,15 @@ private:
         return ::recv(
             _sock_fd,
             boost::asio::buffer_cast<char *>(buff),
-            boost::asio::buffer_size(buff),
-            0
+            boost::asio::buffer_size(buff), 0
         );
     }
 
-    size_t send(const boost::asio::const_buffer &buff){
+    ssize_t send(const boost::asio::const_buffer &buff){
         return ::send(
             _sock_fd,
             boost::asio::buffer_cast<const char *>(buff),
-            boost::asio::buffer_size(buff),
-            0
+            boost::asio::buffer_size(buff), 0
         );
     }
 };
diff --git a/host/lib/transport/vrt_packet_handler.hpp b/host/lib/transport/vrt_packet_handler.hpp
index c0d6bbe12..221e2bfa6 100644
--- a/host/lib/transport/vrt_packet_handler.hpp
+++ b/host/lib/transport/vrt_packet_handler.hpp
@@ -329,7 +329,9 @@ namespace vrt_packet_handler{
             );
 
             //commit the samples to the zero-copy interface
-            send_buffs[i]->commit(if_packet_info.num_packet_words32*sizeof(boost::uint32_t));
+            if (send_buffs[i]->commit(if_packet_info.num_packet_words32*sizeof(boost::uint32_t)) < num_samps){
+                std::cerr << "commit to send buffer returned less than commit size" << std::endl;
+            }
         }
     }
 
diff --git a/host/lib/transport/zero_copy.cpp b/host/lib/transport/zero_copy.cpp
index 27f41329b..42f69d77b 100644
--- a/host/lib/transport/zero_copy.cpp
+++ b/host/lib/transport/zero_copy.cpp
@@ -71,7 +71,9 @@ managed_recv_buffer::sptr phony_zero_copy_recv_if::get_recv_buff(void){
     boost::uint8_t *recv_mem = new boost::uint8_t[_impl->max_buff_size];
 
     //call recv() with timeout option
-    size_t num_bytes = this->recv(boost::asio::buffer(recv_mem, _impl->max_buff_size));
+    ssize_t num_bytes = this->recv(boost::asio::buffer(recv_mem, _impl->max_buff_size));
+
+    if (num_bytes <= 0) return managed_recv_buffer::sptr(); //NULL sptr
 
     //create a new managed buffer to house the data
     return managed_recv_buffer::sptr(
@@ -86,7 +88,7 @@ managed_recv_buffer::sptr phony_zero_copy_recv_if::get_recv_buff(void){
 //! phony zero-copy send buffer implementation
 class managed_send_buffer_impl : public managed_send_buffer{
 public:
-    typedef boost::function<size_t(const boost::asio::const_buffer &)> send_fcn_t;
+    typedef boost::function<ssize_t(const boost::asio::const_buffer &)> send_fcn_t;
 
     managed_send_buffer_impl(
         const boost::asio::mutable_buffer &buff,
@@ -102,8 +104,8 @@ public:
         /* NOP */
     }
 
-    void commit(size_t num_bytes){
-        _send_fcn(boost::asio::buffer(_buff, num_bytes));
+    ssize_t commit(size_t num_bytes){
+        return _send_fcn(boost::asio::buffer(_buff, num_bytes));
     }
 
 private:
diff --git a/host/lib/usrp/usrp2/io_impl.cpp b/host/lib/usrp/usrp2/io_impl.cpp
index 0853f48be..7e231095f 100644
--- a/host/lib/usrp/usrp2/io_impl.cpp
+++ b/host/lib/usrp/usrp2/io_impl.cpp
@@ -85,7 +85,7 @@ void usrp2_impl::io_impl::recv_pirate_loop(
     recv_pirate_crew_raiding = true;
     while(recv_pirate_crew_raiding){
         managed_recv_buffer::sptr buff = zc_if->get_recv_buff();
-        if (buff->size() == 0) continue; //ignore timeout buffers
+        if (not buff.get()) continue; //ignore timeout/error buffers
 
         try{
             //extract the vrt header packet info