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//
// Copyright 2011-2012 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/>.
//
#include "simple_claimer.hpp"
#include <uhd/transport/usb_zero_copy.hpp>
#include <uhd/transport/buffer_pool.hpp>
#include <uhd/utils/byteswap.hpp>
#include <uhd/utils/msg.hpp>
#include <boost/foreach.hpp>
#include <boost/make_shared.hpp>
#include <vector>
#include <iostream>
using namespace uhd::transport;
/***********************************************************************
* USB zero copy wrapper - managed receive buffer
**********************************************************************/
class usb_zero_copy_wrapper_mrb : public managed_recv_buffer{
public:
usb_zero_copy_wrapper_mrb(void){/*NOP*/}
void release(void){
_mrb.reset(); //decrement ref count, other MRB's may hold a ref
_claimer.release();
}
UHD_INLINE sptr get_new(
managed_recv_buffer::sptr &mrb, size_t &offset_bytes,
const double timeout, size_t &index
){
if (not mrb or not _claimer.claim_with_wait(timeout)) return sptr();
index++; //advances the caller's buffer
//hold a copy of the buffer shared pointer
_mrb = mrb;
//extract this packet's memory address and length in bytes
char *mem = mrb->cast<char *>() + offset_bytes;
const boost::uint32_t *mem32 = reinterpret_cast<const boost::uint32_t *>(mem);
size_t len = (uhd::wtohx(mem32[0]) & 0xffff)*sizeof(boost::uint32_t); //length in bytes (from VRT header)
//check if this receive buffer has been exhausted
offset_bytes += len;
if (offset_bytes >= mrb->size()) mrb.reset(); //drop caller's ref
return make(this, mem, len);
}
private:
managed_recv_buffer::sptr _mrb;
simple_claimer _claimer;
};
/***********************************************************************
* USB zero copy wrapper - managed send buffer
**********************************************************************/
class usb_zero_copy_wrapper_msb : public managed_send_buffer{
public:
usb_zero_copy_wrapper_msb(const usb_zero_copy::sptr internal, const size_t fragmentation_size):
_internal(internal), _fragmentation_size(fragmentation_size){/*NOP*/}
void release(void){
//get a reference to the VITA header before incrementing
const boost::uint32_t vita_header = reinterpret_cast<const boost::uint32_t *>(_mem_buffer_tip)[0];
_bytes_in_buffer += size();
_mem_buffer_tip += size();
//extract VITA end of packet flag, we must force flush under eof conditions
const bool eop = (uhd::wtohx(vita_header) & (0x1 << 24)) != 0;
const bool full = _bytes_in_buffer >= (_last_send_buff->size() - _fragmentation_size);
if (eop or full){
_last_send_buff->commit(_bytes_in_buffer);
_last_send_buff.reset();
}
}
UHD_INLINE sptr get_new(const double timeout){
if (not _last_send_buff){
_last_send_buff = _internal->get_send_buff(timeout);
if (not _last_send_buff) return sptr();
_mem_buffer_tip = _last_send_buff->cast<char *>();
_bytes_in_buffer = 0;
}
return make(this, _mem_buffer_tip, _fragmentation_size);
}
private:
usb_zero_copy::sptr _internal;
const size_t _fragmentation_size;
managed_send_buffer::sptr _last_send_buff;
size_t _bytes_in_buffer;
char *_mem_buffer_tip;
};
/***********************************************************************
* USB zero copy wrapper implementation
**********************************************************************/
class usb_zero_copy_wrapper : public usb_zero_copy{
public:
usb_zero_copy_wrapper(sptr usb_zc, const size_t frame_boundary):
_internal_zc(usb_zc),
_frame_boundary(frame_boundary),
_next_recv_buff_index(0)
{
for (size_t i = 0; i < this->get_num_recv_frames(); i++){
_mrb_pool.push_back(boost::make_shared<usb_zero_copy_wrapper_mrb>());
}
_the_only_msb = boost::make_shared<usb_zero_copy_wrapper_msb>(usb_zc, frame_boundary);
}
managed_recv_buffer::sptr get_recv_buff(double timeout){
//attempt to get a managed recv buffer
if (not _last_recv_buff){
_last_recv_buff = _internal_zc->get_recv_buff(timeout);
_last_recv_offset = 0; //reset offset into buffer
}
//get the buffer to be returned to the user
if (_next_recv_buff_index == _mrb_pool.size()) _next_recv_buff_index = 0;
return _mrb_pool[_next_recv_buff_index]->get_new(
_last_recv_buff, _last_recv_offset, timeout, _next_recv_buff_index
);
}
size_t get_num_recv_frames(void) const{
return _internal_zc->get_num_recv_frames();
}
size_t get_recv_frame_size(void) const{
return std::min(_frame_boundary, _internal_zc->get_recv_frame_size());
}
managed_send_buffer::sptr get_send_buff(double timeout){
return _the_only_msb->get_new(timeout);
}
size_t get_num_send_frames(void) const{
return _internal_zc->get_num_send_frames();
}
size_t get_send_frame_size(void) const{
return std::min(_frame_boundary, _internal_zc->get_send_frame_size());
}
private:
sptr _internal_zc;
size_t _frame_boundary;
std::vector<boost::shared_ptr<usb_zero_copy_wrapper_mrb> > _mrb_pool;
boost::shared_ptr<usb_zero_copy_wrapper_msb> _the_only_msb;
//state for last recv buffer to create multiple managed buffers
managed_recv_buffer::sptr _last_recv_buff;
size_t _last_recv_offset;
size_t _next_recv_buff_index;
};
/***********************************************************************
* USB zero copy wrapper factory function
**********************************************************************/
usb_zero_copy::sptr usb_zero_copy::make_wrapper(
sptr usb_zc, size_t usb_frame_boundary
){
return sptr(new usb_zero_copy_wrapper(usb_zc, usb_frame_boundary));
}
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