usrp-e100: replaced safe managed buffers in usrp-e100 mmap with custom ones

the buffers are reusable and the overhead is reduced (nothing to malloc)

also removed the zero_copy.cpp (not needed anymore)

need to test on device...

3 files changed, 112 insertions, 163 deletions

diff --git a/host/lib/transport/CMakeLists.txt b/host/lib/transport/CMakeLists.txt
index 8765c6703..a66a58d32 100644
--- a/host/lib/transport/CMakeLists.txt
+++ b/host/lib/transport/CMakeLists.txt
@@ -77,5 +77,4 @@ LIBUHD_APPEND_SOURCES(
     ${CMAKE_CURRENT_SOURCE_DIR}/udp_simple.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/udp_zero_copy_asio.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/vrt_packet_handler.hpp
-    ${CMAKE_CURRENT_SOURCE_DIR}/zero_copy.cpp
 )
diff --git a/host/lib/transport/zero_copy.cpp b/host/lib/transport/zero_copy.cpp
deleted file mode 100644
index b91eaae1d..000000000
--- a/host/lib/transport/zero_copy.cpp
+++ /dev/null
@@ -1,114 +0,0 @@
-//
-// Copyright 2010-2011 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 <uhd/transport/zero_copy.hpp>
-
-using namespace uhd::transport;
-
-/***********************************************************************
- * Safe managed receive buffer
- **********************************************************************/
-static void release_nop(void){
-    /* NOP */
-}
-
-class safe_managed_receive_buffer : public managed_recv_buffer{
-public:
-    safe_managed_receive_buffer(
-        const void *buff, size_t size, const release_fcn_t &release_fcn
-    ):
-        _buff(buff), _size(size), _release_fcn(release_fcn)
-    {
-        /* NOP */
-    }
-
-    ~safe_managed_receive_buffer(void){
-        _release_fcn();
-    }
-
-    void release(void){
-        release_fcn_t release_fcn = _release_fcn;
-        _release_fcn = &release_nop;
-        return release_fcn();
-    }
-
-private:
-    const void *get_buff(void) const{
-        return _buff;
-    }
-
-    size_t get_size(void) const{
-        return _size;
-    }
-
-    const void *_buff;
-    size_t _size;
-    release_fcn_t _release_fcn;
-};
-
-managed_recv_buffer::sptr managed_recv_buffer::make_safe(
-    const void *buff, size_t size, const release_fcn_t &release_fcn
-){
-    return sptr(new safe_managed_receive_buffer(buff, size, release_fcn));
-}
-
-/***********************************************************************
- * Safe managed send buffer
- **********************************************************************/
-static void commit_nop(size_t){
-    /* NOP */
-}
-
-class safe_managed_send_buffer : public managed_send_buffer{
-public:
-    safe_managed_send_buffer(
-        void *buff, size_t size, const commit_fcn_t &commit_fcn
-    ):
-        _buff(buff), _size(size), _commit_fcn(commit_fcn)
-    {
-        /* NOP */
-    }
-
-    ~safe_managed_send_buffer(void){
-        _commit_fcn(0);
-    }
-
-    void commit(size_t num_bytes){
-        commit_fcn_t commit_fcn = _commit_fcn;
-        _commit_fcn = &commit_nop;
-        return commit_fcn(num_bytes);
-    }
-
-private:
-    void *get_buff(void) const{
-        return _buff;
-    }
-
-    size_t get_size(void) const{
-        return _size;
-    }
-
-    void *_buff;
-    size_t _size;
-    commit_fcn_t _commit_fcn;
-};
-
-safe_managed_send_buffer::sptr managed_send_buffer::make_safe(
-    void *buff, size_t size, const commit_fcn_t &commit_fcn
-){
-    return sptr(new safe_managed_send_buffer(buff, size, commit_fcn));
-}
diff --git a/host/lib/usrp/usrp_e100/usrp_e100_mmap_zero_copy.cpp b/host/lib/usrp/usrp_e100/usrp_e100_mmap_zero_copy.cpp
index 4e0137fdb..c155d426a 100644
--- a/host/lib/usrp/usrp_e100/usrp_e100_mmap_zero_copy.cpp
+++ b/host/lib/usrp/usrp_e100/usrp_e100_mmap_zero_copy.cpp
@@ -22,7 +22,7 @@
 #include <sys/mman.h> //mmap
 #include <unistd.h> //getpagesize
 #include <poll.h> //poll
-#include <boost/bind.hpp>
+#include <vector>
 #include <iostream>
 
 using namespace uhd;
@@ -33,6 +33,82 @@ static const bool sp_verbose = false; //slow-path verbose
 static const size_t poll_breakout = 10; //how many poll timeouts constitute a full timeout
 
 /***********************************************************************
+ * Reusable managed receiver buffer:
+ *  - The buffer knows how to claim and release a frame.
+ **********************************************************************/
+class usrp_e100_mmap_zero_copy_mrb : public managed_recv_buffer{
+public:
+    usrp_e100_mmap_zero_copy_mrb(void *mem, ring_buffer_info *info):
+        _mem(mem), _info(info) { /* NOP */ }
+
+    void release(void){
+        if (_info->flags != RB_USER_PROCESS) return;
+        if (fp_verbose) std::cout << "recv buff: release" << std::endl;
+        _info->flags = RB_KERNEL; //release the frame
+    }
+
+    bool ready(void){return _info->flags & RB_USER;}
+
+    sptr get_new(void){
+        if (fp_verbose) std::cout << "  make_recv_buff: " << get_size() << std::endl;
+        _info->flags = RB_USER_PROCESS; //claim the frame
+        return sptr(this, &usrp_e100_mmap_zero_copy_mrb::fake_deleter);
+    }
+
+private:
+    static void fake_deleter(void *obj){
+        static_cast<usrp_e100_mmap_zero_copy_mrb *>(obj)->release();
+    }
+
+    const void *get_buff(void) const{return _mem;}
+    size_t get_size(void) const{return _info->len;}
+
+    void *_mem;
+    ring_buffer_info *_info;
+};
+
+/***********************************************************************
+ * Reusable managed send buffer:
+ *  - The buffer knows how to claim and release a frame.
+ **********************************************************************/
+class usrp_e100_mmap_zero_copy_msb : public managed_send_buffer{
+public:
+    usrp_e100_mmap_zero_copy_msb(void *mem, ring_buffer_info *info, size_t len, int fd):
+        _mem(mem), _info(info), _len(len), _fd(fd) { /* NOP */ }
+
+    void commit(size_t len){
+        if (_info->flags != RB_USER_PROCESS) return;
+        if (fp_verbose) std::cout << "send buff: commit " << len << std::endl;
+        _info->len = len;
+        _info->flags = RB_USER; //release the frame
+        if (::write(_fd, NULL, 0) < 0){ //notifies the kernel
+            std::cerr << UHD_THROW_SITE_INFO("write error") << std::endl;
+        }
+    }
+
+    bool ready(void){return _info->flags & RB_KERNEL;}
+
+    sptr get_new(void){
+        if (fp_verbose) std::cout << "  make_send_buff: " << get_size() << std::endl;
+        _info->flags = RB_USER_PROCESS; //claim the frame
+        return sptr(this, &usrp_e100_mmap_zero_copy_msb::fake_deleter);
+    }
+
+private:
+    static void fake_deleter(void *obj){
+        static_cast<usrp_e100_mmap_zero_copy_msb *>(obj)->commit(0);
+    }
+
+    void *get_buff(void) const{return _mem;}
+    size_t get_size(void) const{return _len;}
+
+    void *_mem;
+    ring_buffer_info *_info;
+    size_t _len;
+    int _fd;
+};
+
+/***********************************************************************
  * The zero copy interface implementation
  **********************************************************************/
 class usrp_e100_mmap_zero_copy_impl : public zero_copy_if{
@@ -81,13 +157,32 @@ public:
             std::cout << "send_buff_off: " << send_buff_off << std::endl;
         }
 
+        //pointers to sections in the mapped memory
+        ring_buffer_info (*recv_info)[], (*send_info)[];
+        char *recv_buff, *send_buff;
+
         //set the internal pointers for info and buffers
         typedef ring_buffer_info (*rbi_pta)[];
         char *rb_ptr = reinterpret_cast<char *>(_mapped_mem);
-        _recv_info = reinterpret_cast<rbi_pta>(rb_ptr + recv_info_off);
-        _recv_buff = rb_ptr + recv_buff_off;
-        _send_info = reinterpret_cast<rbi_pta>(rb_ptr + send_info_off);
-        _send_buff = rb_ptr + send_buff_off;
+        recv_info = reinterpret_cast<rbi_pta>(rb_ptr + recv_info_off);
+        recv_buff = rb_ptr + recv_buff_off;
+        send_info = reinterpret_cast<rbi_pta>(rb_ptr + send_info_off);
+        send_buff = rb_ptr + send_buff_off;
+
+        //initialize the managed receive buffers
+        for (size_t i = 0; i < get_num_recv_frames(); i++){
+            _mrb_pool.push_back(usrp_e100_mmap_zero_copy_mrb(
+                recv_buff + get_recv_frame_size()*i, (*recv_info) + i
+            ));
+        }
+
+        //initialize the managed send buffers
+        for (size_t i = 0; i < get_num_recv_frames(); i++){
+            _msb_pool.push_back(usrp_e100_mmap_zero_copy_msb(
+                send_buff + get_send_frame_size()*i, (*send_info) + i,
+                get_send_frame_size(), _fd
+            ));
+        }
     }
 
     ~usrp_e100_mmap_zero_copy_impl(void){
@@ -97,13 +192,10 @@ public:
 
     managed_recv_buffer::sptr get_recv_buff(double timeout){
         if (fp_verbose) std::cout << "get_recv_buff: " << _recv_index << std::endl;
-
-        //grab pointers to the info and buffer
-        ring_buffer_info *info = (*_recv_info) + _recv_index;
-        void *mem = _recv_buff + _frame_size*_recv_index;
+        usrp_e100_mmap_zero_copy_mrb &mrb = _mrb_pool[_recv_index];
 
         //poll/wait for a ready frame
-        if (not (info->flags & RB_USER)){
+        if (not mrb.ready()){
             for (size_t i = 0; i < poll_breakout; i++){
                 pollfd pfd;
                 pfd.fd = _fd;
@@ -115,18 +207,11 @@ public:
             return managed_recv_buffer::sptr(); //timed-out for real
         } found_user_frame:
 
-        //the process has claimed the frame
-        info->flags = RB_USER_PROCESS;
-
         //increment the index for the next call
-        if (++_recv_index == size_t(_rb_size.num_rx_frames)) _recv_index = 0;
+        if (++_recv_index == get_num_recv_frames()) _recv_index = 0;
 
         //return the managed buffer for this frame
-        if (fp_verbose) std::cout << "  make_recv_buff: " << info->len << std::endl;
-        return managed_recv_buffer::make_safe(
-            mem, info->len,
-            boost::bind(&usrp_e100_mmap_zero_copy_impl::release, this, info)
-        );
+        return mrb.get_new();
     }
 
     size_t get_num_recv_frames(void) const{
@@ -139,13 +224,10 @@ public:
 
     managed_send_buffer::sptr get_send_buff(double timeout){
         if (fp_verbose) std::cout << "get_send_buff: " << _send_index << std::endl;
-
-        //grab pointers to the info and buffer
-        ring_buffer_info *info = (*_send_info) + _send_index;
-        void *mem = _send_buff + _frame_size*_send_index;
+        usrp_e100_mmap_zero_copy_msb &msb = _msb_pool[_send_index];
 
         //poll/wait for a ready frame
-        if (not (info->flags & RB_KERNEL)){
+        if (not msb.ready()){
             pollfd pfd;
             pfd.fd = _fd;
             pfd.events = POLLOUT;
@@ -155,14 +237,10 @@ public:
         }
 
         //increment the index for the next call
-        if (++_send_index == size_t(_rb_size.num_tx_frames)) _send_index = 0;
+        if (++_send_index == get_num_send_frames()) _send_index = 0;
 
         //return the managed buffer for this frame
-        if (fp_verbose) std::cout << "  make_send_buff: " << _frame_size << std::endl;
-        return managed_send_buffer::make_safe(
-            mem, _frame_size,
-            boost::bind(&usrp_e100_mmap_zero_copy_impl::commit, this, info, _1)
-        );
+        return msb.get_new();
     }
 
     size_t get_num_send_frames(void) const{
@@ -174,21 +252,7 @@ public:
     }
 
 private:
-
-    void release(ring_buffer_info *info){
-        if (fp_verbose) std::cout << "recv buff: release" << std::endl;
-        info->flags = RB_KERNEL;
-    }
-
-    void commit(ring_buffer_info *info, size_t len){
-        if (fp_verbose) std::cout << "send buff: commit " << len << std::endl;
-        info->len = len;
-        info->flags = RB_USER;
-        if (::write(_fd, NULL, 0) < 0){
-            std::cerr << UHD_THROW_SITE_INFO("write error") << std::endl;
-        }
-    }
-
+    //file descriptor for mmap
     int _fd;
 
     //the mapped memory itself
@@ -198,9 +262,9 @@ private:
     usrp_e_ring_buffer_size_t _rb_size;
     size_t _frame_size, _map_size;
 
-    //pointers to sections in the mapped memory
-    ring_buffer_info (*_recv_info)[], (*_send_info)[];
-    char *_recv_buff, *_send_buff;
+    //re-usable managed buffers
+    std::vector<usrp_e100_mmap_zero_copy_mrb> _mrb_pool;
+    std::vector<usrp_e100_mmap_zero_copy_msb> _msb_pool;
 
     //indexes into sub-sections of mapped memory
     size_t _recv_index, _send_index;