1 files changed, 87 insertions, 0 deletions
diff --git a/host/lib/usrp/common/recv_packet_demuxer.cpp b/host/lib/usrp/common/recv_packet_demuxer.cpp
new file mode 100644
index 000000000..f2cfe3bb0
--- /dev/null
+++ b/host/lib/usrp/common/recv_packet_demuxer.cpp
@@ -0,0 +1,87 @@
+//
+// Copyright 2011 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/>.
+//
+
+#include "recv_packet_demuxer.hpp"
+#include <uhd/utils/msg.hpp>
+#include <uhd/utils/byteswap.hpp>
+#include <boost/thread/mutex.hpp>
+#include <queue>
+#include <deque>
+#include <vector>
+
+using namespace uhd;
+using namespace uhd::usrp;
+using namespace uhd::transport;
+
+static UHD_INLINE boost::uint32_t extract_sid(managed_recv_buffer::sptr &buff){
+    //ASSUME that the data is in little endian format
+    return uhd::wtohx(buff->cast<const boost::uint32_t *>()[1]);
+}
+
+class recv_packet_demuxer_impl : public uhd::usrp::recv_packet_demuxer{
+public:
+    recv_packet_demuxer_impl(
+        transport::zero_copy_if::sptr transport,
+        const size_t size,
+        const boost::uint32_t sid_base
+    ):
+        _transport(transport), _sid_base(sid_base), _queues(size)
+    {
+        /* NOP */
+    }
+
+    managed_recv_buffer::sptr get_recv_buff(const size_t index, const double timeout){
+        boost::mutex::scoped_lock lock(_mutex);
+        managed_recv_buffer::sptr buff;
+
+        //there is already an entry in the queue, so pop that
+        if (not _queues[index].wrapper.empty()){
+            std::swap(buff, _queues[index].wrapper.front());
+            _queues[index].wrapper.pop();
+            return buff;
+        }
+
+        while (true){
+            //otherwise call into the transport
+            buff = _transport->get_recv_buff(timeout);
+            if (buff.get() == NULL) return buff; //timeout
+
+            //check the stream id to know which channel
+            const size_t rx_index = extract_sid(buff) - _sid_base;
+            if (rx_index == index) return buff; //got expected message
+
+            //otherwise queue and try again
+            if (rx_index < _queues.size()) _queues[rx_index].wrapper.push(buff);
+            else UHD_MSG(error) << "Got a data packet with unknown SID " << extract_sid(buff) << std::endl;
+        }
+    }
+
+private:
+    transport::zero_copy_if::sptr _transport;
+    const boost::uint32_t _sid_base;
+    boost::mutex _mutex;
+    struct channel_guts_type{
+        channel_guts_type(void): wrapper(container){}
+        std::deque<managed_recv_buffer::sptr> container;
+        std::queue<managed_recv_buffer::sptr> wrapper;
+    };
+    std::vector<channel_guts_type> _queues;
+};
+
+recv_packet_demuxer::sptr recv_packet_demuxer::make(transport::zero_copy_if::sptr transport, const size_t size, const boost::uint32_t sid_base){
+    return sptr(new recv_packet_demuxer_impl(transport, size, sid_base));
+}