1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
|
//
// Copyright 2010 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/udp_zero_copy.hpp>
#include <uhd/utils/assert.hpp>
#include <boost/cstdint.hpp>
#include <boost/asio.hpp>
#include <boost/format.hpp>
#include <iostream>
using namespace uhd::transport;
/***********************************************************************
* Constants
**********************************************************************/
static const size_t MIN_SOCK_BUFF_SIZE = size_t(100e3);
static const size_t MAX_DGRAM_SIZE = 1500; //assume max size on send and recv
static const double RECV_TIMEOUT = 0.1; //100 ms
/***********************************************************************
* Zero Copy UDP implementation with ASIO:
* This is the portable zero copy implementation for systems
* where a faster, platform specific solution is not available.
* However, it is not a true zero copy implementation as each
* send and recv requires a copy operation to/from userspace.
**********************************************************************/
class udp_zero_copy_impl:
public phony_zero_copy_recv_if,
public phony_zero_copy_send_if,
public udp_zero_copy
{
public:
typedef boost::shared_ptr<udp_zero_copy_impl> sptr;
udp_zero_copy_impl(
const std::string &addr,
const std::string &port
):
phony_zero_copy_recv_if(MAX_DGRAM_SIZE),
phony_zero_copy_send_if(MAX_DGRAM_SIZE)
{
//std::cout << boost::format("Creating udp transport for %s %s") % addr % port << std::endl;
// resolve the address
boost::asio::ip::udp::resolver resolver(_io_service);
boost::asio::ip::udp::resolver::query query(boost::asio::ip::udp::v4(), addr, port);
boost::asio::ip::udp::endpoint receiver_endpoint = *resolver.resolve(query);
// create, open, and connect the socket
_socket = new boost::asio::ip::udp::socket(_io_service);
_socket->open(boost::asio::ip::udp::v4());
_socket->connect(receiver_endpoint);
_sock_fd = _socket->native();
}
~udp_zero_copy_impl(void){
delete _socket;
}
//get size for internal socket buffer
template <typename Opt> size_t get_buff_size(void) const{
Opt option;
_socket->get_option(option);
return option.value();
}
//set size for internal socket buffer
template <typename Opt> size_t resize_buff(size_t num_bytes){
Opt option(num_bytes);
_socket->set_option(option);
return get_buff_size<Opt>();
}
//The number of frames is approximately the buffer size divided by the max datagram size.
//In reality, this is a phony zero-copy interface and the number of frames is infinite.
//However, its sensible to advertise a frame count that is approximate to buffer size.
//This way, the transport caller will have an idea about how much buffering to create.
size_t get_num_recv_frames(void) const{
return this->get_buff_size<boost::asio::socket_base::receive_buffer_size>()/MAX_DGRAM_SIZE;
}
size_t get_num_send_frames(void) const{
return this->get_buff_size<boost::asio::socket_base::send_buffer_size>()/MAX_DGRAM_SIZE;
}
private:
boost::asio::ip::udp::socket *_socket;
boost::asio::io_service _io_service;
int _sock_fd;
size_t recv(const boost::asio::mutable_buffer &buff){
//setup timeval for timeout
timeval tv;
tv.tv_sec = 0;
tv.tv_usec = int(RECV_TIMEOUT*1e6);
//setup rset for timeout
fd_set rset;
FD_ZERO(&rset);
FD_SET(_sock_fd, &rset);
//call select to perform timed wait
if (::select(_sock_fd+1, &rset, NULL, NULL, &tv) <= 0) return 0;
return ::recv(
_sock_fd,
boost::asio::buffer_cast<char *>(buff),
boost::asio::buffer_size(buff),
0
);
}
size_t send(const boost::asio::const_buffer &buff){
return ::send(
_sock_fd,
boost::asio::buffer_cast<const char *>(buff),
boost::asio::buffer_size(buff),
0
);
}
};
/***********************************************************************
* UDP zero copy make function
**********************************************************************/
template<typename Opt> static void resize_buff_helper(
udp_zero_copy_impl::sptr udp_trans,
size_t target_size,
const std::string &name
){
//resize the buffer if size was provided
if (target_size > 0){
size_t actual_size = udp_trans->resize_buff<Opt>(target_size);
if (target_size != actual_size) std::cout << boost::format(
"Target %s sock buff size: %d bytes\n"
"Actual %s sock buff size: %d bytes"
) % name % target_size % name % actual_size << std::endl;
else std::cout << boost::format(
"Current %s sock buff size: %d bytes"
) % name % actual_size << std::endl;
}
//otherwise, ensure that the buffer is at least the minimum size
else if (udp_trans->get_buff_size<Opt>() < MIN_SOCK_BUFF_SIZE){
resize_buff_helper<Opt>(udp_trans, MIN_SOCK_BUFF_SIZE, name);
}
}
udp_zero_copy::sptr udp_zero_copy::make(
const std::string &addr,
const std::string &port,
size_t recv_buff_size,
size_t send_buff_size
){
udp_zero_copy_impl::sptr udp_trans(new udp_zero_copy_impl(addr, port));
//call the helper to resize send and recv buffers
resize_buff_helper<boost::asio::socket_base::receive_buffer_size>(udp_trans, recv_buff_size, "recv");
resize_buff_helper<boost::asio::socket_base::send_buffer_size> (udp_trans, send_buff_size, "send");
return udp_trans;
}
|
