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
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
|
#include "iolooper.h"
#include "qemu-common.h"
/* An implementation of iolooper.h based on Unix select() */
#ifdef _WIN32
# include <winsock2.h>
#else
# include <sys/types.h>
# include <sys/select.h>
#endif
#include "sockets.h"
struct IoLooper {
fd_set reads[1];
fd_set writes[1];
fd_set reads_result[1];
fd_set writes_result[1];
int max_fd;
int max_fd_valid;
};
IoLooper*
iolooper_new(void)
{
IoLooper* iol = malloc(sizeof(*iol));
iolooper_reset(iol);
return iol;
}
void
iolooper_free( IoLooper* iol )
{
free(iol);
}
void
iolooper_reset( IoLooper* iol )
{
FD_ZERO(iol->reads);
FD_ZERO(iol->writes);
iol->max_fd = -1;
iol->max_fd_valid = 1;
}
static void
iolooper_add_fd( IoLooper* iol, int fd )
{
if (iol->max_fd_valid && fd > iol->max_fd) {
iol->max_fd = fd;
}
}
static void
iolooper_del_fd( IoLooper* iol, int fd )
{
if (iol->max_fd_valid && fd == iol->max_fd)
iol->max_fd_valid = 0;
}
void
iolooper_modify( IoLooper* iol, int fd, int oldflags, int newflags )
{
if (fd < 0)
return;
int changed = oldflags ^ newflags;
if ((changed & IOLOOPER_READ) != 0) {
if ((newflags & IOLOOPER_READ) != 0)
iolooper_add_read(iol, fd);
else
iolooper_del_read(iol, fd);
}
if ((changed & IOLOOPER_WRITE) != 0) {
if ((newflags & IOLOOPER_WRITE) != 0)
iolooper_add_write(iol, fd);
else
iolooper_del_write(iol, fd);
}
}
static int
iolooper_fd_count( IoLooper* iol )
{
int max_fd = iol->max_fd;
int fd;
if (iol->max_fd_valid)
return max_fd + 1;
/* recompute max fd */
for (fd = 0; fd < FD_SETSIZE; fd++) {
if (!FD_ISSET(fd, iol->reads) && !FD_ISSET(fd, iol->writes))
continue;
max_fd = fd;
}
iol->max_fd = max_fd;
iol->max_fd_valid = 1;
return max_fd + 1;
}
void
iolooper_add_read( IoLooper* iol, int fd )
{
if (fd >= 0) {
iolooper_add_fd(iol, fd);
FD_SET(fd, iol->reads);
}
}
void
iolooper_add_write( IoLooper* iol, int fd )
{
if (fd >= 0) {
iolooper_add_fd(iol, fd);
FD_SET(fd, iol->writes);
}
}
void
iolooper_del_read( IoLooper* iol, int fd )
{
if (fd >= 0) {
iolooper_del_fd(iol, fd);
FD_CLR(fd, iol->reads);
}
}
void
iolooper_del_write( IoLooper* iol, int fd )
{
if (fd >= 0) {
iolooper_del_fd(iol, fd);
FD_CLR(fd, iol->writes);
}
}
int
iolooper_poll( IoLooper* iol )
{
int count = iolooper_fd_count(iol);
int ret;
fd_set errs;
if (count == 0)
return 0;
FD_ZERO(&errs);
do {
struct timeval tv;
tv.tv_sec = tv.tv_usec = 0;
iol->reads_result[0] = iol->reads[0];
iol->writes_result[0] = iol->writes[0];
ret = select( count, iol->reads_result, iol->writes_result, &errs, &tv);
} while (ret < 0 && errno == EINTR);
return ret;
}
int
iolooper_wait( IoLooper* iol, int64_t duration )
{
int count = iolooper_fd_count(iol);
int ret;
fd_set errs;
struct timeval tm0, *tm = NULL;
if (count == 0)
return 0;
if (duration < 0)
tm = NULL;
else {
tm = &tm0;
tm->tv_sec = duration / 1000;
tm->tv_usec = (duration - 1000*tm->tv_sec) * 1000;
}
FD_ZERO(&errs);
do {
iol->reads_result[0] = iol->reads[0];
iol->writes_result[0] = iol->writes[0];
ret = select( count, iol->reads_result, iol->writes_result, &errs, tm);
if (ret == 0) {
// Indicates timeout
errno = ETIMEDOUT;
}
} while (ret < 0 && errno == EINTR);
return ret;
}
int
iolooper_is_read( IoLooper* iol, int fd )
{
return FD_ISSET(fd, iol->reads_result);
}
int
iolooper_is_write( IoLooper* iol, int fd )
{
return FD_ISSET(fd, iol->writes_result);
}
int
iolooper_has_operations( IoLooper* iol )
{
return iolooper_fd_count(iol) > 0;
}
int64_t
iolooper_now(void)
{
struct timeval time_now;
return gettimeofday(&time_now, NULL) ? -1 : (int64_t)time_now.tv_sec * 1000LL +
time_now.tv_usec / 1000;
}
int
iolooper_wait_absolute(IoLooper* iol, int64_t deadline)
{
int64_t timeout = deadline - iolooper_now();
/* If the deadline has passed, set the timeout to 0, this allows us
* to poll the file descriptor nonetheless */
if (timeout < 0)
timeout = 0;
return iolooper_wait(iol, timeout);
}
|