1 files changed, 164 insertions, 0 deletions
diff --git a/host/include/uhd/transport/zero_copy.hpp b/host/include/uhd/transport/zero_copy.hpp
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index 000000000..1dc0e8e26
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+++ b/host/include/uhd/transport/zero_copy.hpp
@@ -0,0 +1,164 @@
+//
+// Copyright 2010-2012 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#ifndef INCLUDED_UHD_TRANSPORT_ZERO_COPY_HPP
+#define INCLUDED_UHD_TRANSPORT_ZERO_COPY_HPP
+
+#include <uhd/config.hpp>
+#include <boost/utility.hpp>
+#include <boost/shared_ptr.hpp>
+#include <boost/intrusive_ptr.hpp>
+#include <boost/detail/atomic_count.hpp>
+
+namespace uhd{ namespace transport{
+
+    //! Simple managed buffer with release interface
+    class UHD_API managed_buffer{
+    public:
+        managed_buffer(void):_ref_count(0){}
+
+        /*!
+         * Signal to the transport that we are done with the buffer.
+         * This should be called to release the buffer to the transport object.
+         * After calling, the referenced memory should be considered invalid.
+         */
+        virtual void release(void) = 0;
+
+        /*!
+         * Use commit() to re-write the length (for use with send buffers).
+         * \param num_bytes the number of bytes written into the buffer
+         */
+        UHD_INLINE void commit(size_t num_bytes){
+            _length = num_bytes;
+        }
+
+        /*!
+         * Get a pointer to the underlying buffer.
+         * \return a pointer into memory
+         */
+        template <class T> UHD_INLINE T cast(void) const{
+            return static_cast<T>(_buffer);
+        }
+
+        /*!
+         * Get the size of the underlying buffer.
+         * \return the number of bytes
+         */
+        UHD_INLINE size_t size(void) const{
+            return _length;
+        }
+
+        //! Create smart pointer to a reusable managed buffer
+        template <typename T> UHD_INLINE boost::intrusive_ptr<T> make(
+            T *p, void *buffer, size_t length
+        ){
+            _buffer = buffer;
+            _length = length;
+            return boost::intrusive_ptr<T>(p);
+        }
+
+        boost::detail::atomic_count _ref_count;
+
+    protected:
+        void *_buffer;
+        size_t _length;
+    };
+
+    UHD_INLINE void intrusive_ptr_add_ref(managed_buffer *p){
+        ++(p->_ref_count);
+    }
+
+    UHD_INLINE void intrusive_ptr_release(managed_buffer *p){
+        if (--(p->_ref_count) == 0) p->release();
+    }
+
+    /*!
+     * A managed receive buffer:
+     * Contains a reference to transport-managed memory,
+     * and a method to release the memory after reading.
+     */
+    class UHD_API managed_recv_buffer : public managed_buffer{
+    public:
+        typedef boost::intrusive_ptr<managed_recv_buffer> sptr;
+    };
+
+    /*!
+     * A managed send buffer:
+     * Contains a reference to transport-managed memory,
+     * and a method to commit the memory after writing.
+     */
+    class UHD_API managed_send_buffer : public managed_buffer{
+    public:
+        typedef boost::intrusive_ptr<managed_send_buffer> sptr;
+    };
+
+    /*!
+     * A zero-copy interface for transport objects.
+     * Provides a way to get send and receive buffers
+     * with memory managed by the transport object.
+     */
+    class UHD_API zero_copy_if : boost::noncopyable{
+    public:
+        typedef boost::shared_ptr<zero_copy_if> sptr;
+
+        /*!
+         * Get a new receive buffer from this transport object.
+         * \param timeout the timeout to get the buffer in seconds
+         * \return a managed buffer, or null sptr on timeout/error
+         */
+        virtual managed_recv_buffer::sptr get_recv_buff(double timeout = 0.1) = 0;
+
+        /*!
+         * Get the number of receive frames:
+         * The number of simultaneous receive buffers in use.
+         * \return number of frames
+         */
+        virtual size_t get_num_recv_frames(void) const = 0;
+
+        /*!
+         * Get the size of a receive frame:
+         * The maximum capacity of a single receive buffer.
+         * \return frame size in bytes
+         */
+        virtual size_t get_recv_frame_size(void) const = 0;
+
+        /*!
+         * Get a new send buffer from this transport object.
+         * \param timeout the timeout to get the buffer in seconds
+         * \return a managed buffer, or null sptr on timeout/error
+         */
+        virtual managed_send_buffer::sptr get_send_buff(double timeout = 0.1) = 0;
+
+        /*!
+         * Get the number of send frames:
+         * The number of simultaneous send buffers in use.
+         * \return number of frames
+         */
+        virtual size_t get_num_send_frames(void) const = 0;
+
+        /*!
+         * Get the size of a send frame:
+         * The maximum capacity of a single send buffer.
+         * \return frame size in bytes
+         */
+        virtual size_t get_send_frame_size(void) const = 0;
+
+    };
+
+}} //namespace
+
+#endif /* INCLUDED_UHD_TRANSPORT_ZERO_COPY_HPP */