Added class to add flow control to any zero_copy_if interface.

3 files changed, 286 insertions, 0 deletions

diff --git a/host/include/uhd/transport/zero_copy_flow_ctrl.hpp b/host/include/uhd/transport/zero_copy_flow_ctrl.hpp
new file mode 100644
index 000000000..8075c503d
--- /dev/null
+++ b/host/include/uhd/transport/zero_copy_flow_ctrl.hpp
@@ -0,0 +1,58 @@
+//

+// Copyright 2017 Ettus Research

+//

+// 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_ZERO_COPY_FLOW_CTRL_HPP

+#define INCLUDED_ZERO_COPY_FLOW_CTRL_HPP

+

+#include <uhd/config.hpp>

+#include <uhd/transport/zero_copy.hpp>

+#include <boost/function.hpp>

+#include <boost/shared_ptr.hpp>

+

+namespace uhd{ namespace transport{

+

+/*!

+ * Flow control function.

+ * \param buff buffer to be sent or receive buffer being released

+ * \return true if OK, false if not

+ */

+typedef boost::function<bool(managed_buffer::sptr buff)> flow_ctrl_func;

+

+/*!

+ * Adds flow control to any zero_copy_if transport.

+ */

+class UHD_API zero_copy_flow_ctrl : public virtual zero_copy_if {

+public:

+    typedef boost::shared_ptr<zero_copy_flow_ctrl> sptr;

+

+    /*!

+     * Make flow controlled transport.

+     *

+     * \param transport a shared pointer to the transport interface

+     * \param send_flow_ctrl optional send flow control function called before buffer is sent

+     * \param recv_flow_ctrl optional receive flow control function called after buffer released

+     */

+    static sptr make(

+        zero_copy_if::sptr transport,

+        flow_ctrl_func send_flow_ctrl,

+        flow_ctrl_func recv_flow_ctrl

+    );

+};

+

+}} //namespace

+

+#endif /* INCLUDED_ZERO_COPY_FLOW_CTRL_HPP */

diff --git a/host/lib/transport/CMakeLists.txt b/host/lib/transport/CMakeLists.txt
index 44c8d59af..a6d84cc4a 100644
--- a/host/lib/transport/CMakeLists.txt
+++ b/host/lib/transport/CMakeLists.txt
@@ -129,6 +129,7 @@ LIBUHD_APPEND_SOURCES(
     ${CMAKE_CURRENT_SOURCE_DIR}/udp_simple.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/chdr.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/muxed_zero_copy_if.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/zero_copy_flow_ctrl.cpp
 )
 
 IF(ENABLE_X300)
diff --git a/host/lib/transport/zero_copy_flow_ctrl.cpp b/host/lib/transport/zero_copy_flow_ctrl.cpp
new file mode 100644
index 000000000..06d7934e2
--- /dev/null
+++ b/host/lib/transport/zero_copy_flow_ctrl.cpp
@@ -0,0 +1,227 @@
+//

+// Copyright 2017 Ettus Research

+//

+// 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/>.

+//

+

+#include <uhd/transport/zero_copy_flow_ctrl.hpp>

+#include <uhd/transport/bounded_buffer.hpp>

+#include <uhd/transport/buffer_pool.hpp>

+#include <uhd/utils/msg.hpp>

+#include <uhd/utils/log.hpp>

+#include <uhd/utils/safe_call.hpp>

+#include <boost/format.hpp>

+#include <boost/make_shared.hpp>

+#include <boost/thread/mutex.hpp>

+#include <boost/thread/thread.hpp>

+#include <boost/bind.hpp>

+

+using namespace uhd;

+using namespace uhd::transport;

+

+typedef bounded_buffer<managed_send_buffer::sptr> bounded_buffer_t;

+

+class zero_copy_flow_ctrl_msb : public managed_send_buffer

+{

+public:

+    zero_copy_flow_ctrl_msb(

+        flow_ctrl_func flow_ctrl

+    ) :

+        _mb(NULL),

+        _flow_ctrl(flow_ctrl)

+    {

+        /* NOP */

+    }

+

+    ~zero_copy_flow_ctrl_msb()

+    {

+        /* NOP */

+    }

+

+    void release()

+    {

+        if (_mb)

+        {

+            _mb->commit(size());

+            while (_flow_ctrl and not _flow_ctrl(_mb)) {}

+            _mb.reset();

+        }

+    }

+

+    UHD_INLINE sptr get(sptr &mb)

+    {

+        _mb = mb;

+        return make(this, _mb->cast<void *>(), _mb->size());

+    }

+

+private:

+    sptr _mb;

+    flow_ctrl_func _flow_ctrl;

+};

+

+class zero_copy_flow_ctrl_mrb : public managed_recv_buffer

+{

+public:

+    zero_copy_flow_ctrl_mrb(

+        flow_ctrl_func flow_ctrl

+    ) :

+        _mb(NULL),

+        _flow_ctrl(flow_ctrl)

+    {

+        /* NOP */

+    }

+

+    ~zero_copy_flow_ctrl_mrb()

+    {

+        /* NOP */

+    }

+

+    void release()

+    {

+        if (_mb)

+        {

+            _mb->commit(size());

+            while (_flow_ctrl and not _flow_ctrl(_mb)) {}

+            _mb.reset();

+        }

+    }

+

+    UHD_INLINE sptr get(sptr &mb)

+    {

+        _mb = mb;

+        return make(this, _mb->cast<void *>(), _mb->size());

+    }

+

+private:

+    sptr _mb;

+    flow_ctrl_func _flow_ctrl;

+};

+

+/***********************************************************************

+ * Zero copy offload transport:

+ * An intermediate transport that utilizes threading to free

+ * the main thread from any receive work.

+ **********************************************************************/

+class zero_copy_flow_ctrl_impl : public zero_copy_flow_ctrl {

+public:

+    typedef boost::shared_ptr<zero_copy_flow_ctrl_impl> sptr;

+

+    zero_copy_flow_ctrl_impl(zero_copy_if::sptr transport,

+        flow_ctrl_func send_flow_ctrl,

+        flow_ctrl_func recv_flow_ctrl) :

+        _transport(transport),

+        _send_buffers(transport->get_num_send_frames()),

+        _recv_buffers(transport->get_num_recv_frames()),

+        _send_buff_index(0),

+        _recv_buff_index(0),

+        _send_flow_ctrl(send_flow_ctrl),

+        _recv_flow_ctrl(recv_flow_ctrl)

+    {

+        UHD_LOG << "Created zero_copy_flow_ctrl" << std::endl;

+

+        for (size_t i = 0; i < transport->get_num_send_frames(); i++)

+        {

+            _send_buffers[i] = boost::make_shared<zero_copy_flow_ctrl_msb>(_send_flow_ctrl);

+        }

+        for (size_t i = 0; i < transport->get_num_recv_frames(); i++)

+        {

+            _recv_buffers[i] = boost::make_shared<zero_copy_flow_ctrl_mrb>(_recv_flow_ctrl);

+        }

+    }

+

+    ~zero_copy_flow_ctrl_impl()

+    {

+    }

+

+    /*******************************************************************

+     * Receive implementation:

+     * Pop the receive buffer pointer from the underlying transport

+     ******************************************************************/

+    UHD_INLINE managed_recv_buffer::sptr get_recv_buff(double timeout)

+    {

+        managed_recv_buffer::sptr ptr;

+        managed_recv_buffer::sptr buff = _transport->get_recv_buff(timeout);

+        if (buff)

+        {

+            boost::shared_ptr<zero_copy_flow_ctrl_mrb> mb = _recv_buffers[_recv_buff_index++];

+            _recv_buff_index %= _recv_buffers.size();

+            ptr = mb->get(buff);

+        }

+        return ptr;

+    }

+

+    UHD_INLINE size_t get_num_recv_frames() const

+    {

+        return _transport->get_num_recv_frames();

+    }

+

+    UHD_INLINE size_t get_recv_frame_size() const

+    {

+        return _transport->get_recv_frame_size();

+    }

+

+    /*******************************************************************

+     * Send implementation:

+     * Pass the send buffer pointer from the underlying transport

+     ******************************************************************/

+    managed_send_buffer::sptr get_send_buff(double timeout)

+    {

+        managed_send_buffer::sptr ptr;

+        managed_send_buffer::sptr buff = _transport->get_send_buff(timeout);

+        if (buff)

+        {

+            boost::shared_ptr<zero_copy_flow_ctrl_msb> mb = _send_buffers[_send_buff_index++];

+            _send_buff_index %= _send_buffers.size();

+            ptr = mb->get(buff);

+        }

+        return ptr;

+    }

+

+    UHD_INLINE size_t get_num_send_frames() const

+    {

+        return _transport->get_num_send_frames();

+    }

+

+    UHD_INLINE size_t get_send_frame_size() const

+    {

+        return _transport->get_send_frame_size();

+    }

+

+private:

+    // The underlying transport

+    zero_copy_if::sptr _transport;

+

+    // buffers

+    std::vector< boost::shared_ptr<zero_copy_flow_ctrl_msb> > _send_buffers;

+    std::vector< boost::shared_ptr<zero_copy_flow_ctrl_mrb> > _recv_buffers;

+    size_t _send_buff_index;

+    size_t _recv_buff_index;

+

+    // Flow control functions

+    flow_ctrl_func _send_flow_ctrl;

+    flow_ctrl_func _recv_flow_ctrl;

+};

+

+zero_copy_flow_ctrl::sptr zero_copy_flow_ctrl::make(

+        zero_copy_if::sptr transport,

+        flow_ctrl_func send_flow_ctrl,

+        flow_ctrl_func recv_flow_ctrl

+)

+{

+    zero_copy_flow_ctrl_impl::sptr zero_copy_flow_ctrl(

+        new zero_copy_flow_ctrl_impl(transport, send_flow_ctrl, recv_flow_ctrl)

+    );

+

+    return zero_copy_flow_ctrl;

+}