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
|
// class for asynchronous logging
// Copyright (C) 2011 Tim Blechmann
//
// 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 2 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; see the file COPYING. If not, write to
// the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
// Boston, MA 02111-1307, USA.
#ifndef UTILITIES_ASYNCHRONOUS_LOG_HPP
#define UTILITIES_ASYNCHRONOUS_LOG_HPP
#include <cstring>
#include <cstdio>
#include <cstdarg>
#include <thread>
#include <array>
#include <boost/lockfree/spsc_queue.hpp>
#include <boost/mpl/if.hpp>
#include <nova-tt/semaphore.hpp>
namespace nova {
namespace asynchronous_log_impl {
struct asynchronous_log:
noncopyable
{
bool log_printf(const char *fmt, ...)
{
va_list vargs;
va_start(vargs, fmt);
bool result = log_printf(fmt, vargs);
va_end(vargs);
return result;
}
bool log_printf(const char *fmt, va_list vargs)
{
std::array<char, 4096> scratchpad;
size_t print_result = vsnprintf(scratchpad.data(), scratchpad.size(), fmt, vargs);
if (print_result >= scratchpad.size())
fprintf(stderr, "warning: log message truncated");
return log(scratchpad.data(), print_result);
}
bool log(const char * string)
{
size_t length = strlen(string);
return log(string, length);
}
bool log(const char * string, size_t length)
{
size_t total_enqueued = buffer.push(string, length);
if (total_enqueued == 0)
return false;
sem.post();
if (total_enqueued == length)
return true;
string += total_enqueued;
length -= total_enqueued;
for (;;) {
size_t enqueued = buffer.push(string, length);
if (enqueued == 0)
continue;
sem.post();
if (enqueued == length)
break;
string += enqueued;
length -= enqueued;
}
return true;
}
size_t read_log(char * out_buffer, size_t size)
{
if (sem.try_wait())
return read(out_buffer, size);
else
return 0;
}
size_t read_log_waiting(char * out_buffer, size_t size)
{
sem.wait();
return read(out_buffer, size);
}
size_t read(char * out_buffer, size_t size)
{
return buffer.pop(out_buffer, size);
}
void interrrupt(void)
{
sem.post();
}
private:
boost::lockfree::spsc_queue<char, boost::lockfree::capacity<262144> > buffer;
nova::semaphore sem;
};
struct asynchronous_log_thread:
asynchronous_log
{
public:
asynchronous_log_thread(void):
running_flag(true), thread_(std::bind(&asynchronous_log_thread::run, this))
{}
~asynchronous_log_thread(void)
{
running_flag = false;
interrrupt();
thread_.join();
}
void run(void)
{
while (running_flag.load()) {
size_t read_chars = read_log_waiting(out_buffer.data(), out_buffer.size());
post_outbuffer(read_chars);
while (read_chars == out_buffer.size()) {
read_chars = read(out_buffer.data(), out_buffer.size());
post_outbuffer(read_chars);
}
}
size_t read_chars = read_log(out_buffer.data(), out_buffer.size());
post_outbuffer(read_chars);
}
void post_outbuffer(size_t read_chars)
{
for (size_t i = 0; i != read_chars; ++i)
putchar(out_buffer[i]);
fflush(stdout);
}
private:
boost::atomic_bool running_flag;
std::thread thread_;
std::array<char, 4096> out_buffer;
};
} /* namespace asynchronous_log_impl */
using asynchronous_log_impl::asynchronous_log;
using asynchronous_log_impl::asynchronous_log_thread;
} /* namespace nova */
#endif /* UTILITIES_ASYNCHRONOUS_LOG_HPP */
|
