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
|
// License: GPLv3 Copyright: 2022, Kovid Goyal, <kovid at kovidgoyal.net>
package utils
import (
"time"
"golang.org/x/sys/unix"
)
type Selector struct {
read_set, write_set, err_set unix.FdSet
read_fds, write_fds, err_fds map[int]bool
}
func CreateSelect(expected_number_of_fds int) *Selector {
var ans Selector
ans.read_fds = make(map[int]bool, expected_number_of_fds)
ans.write_fds = make(map[int]bool, expected_number_of_fds)
ans.err_fds = make(map[int]bool, expected_number_of_fds)
return &ans
}
func (self *Selector) register(fd int, fdset *map[int]bool) {
(*fdset)[fd] = true
}
func (self *Selector) RegisterRead(fd int) {
self.register(fd, &self.read_fds)
}
func (self *Selector) RegisterWrite(fd int) {
self.register(fd, &self.write_fds)
}
func (self *Selector) RegisterError(fd int) {
self.register(fd, &self.err_fds)
}
func (self *Selector) unregister(fd int, fdset *map[int]bool) {
(*fdset)[fd] = false
}
func (self *Selector) UnRegisterRead(fd int) {
self.unregister(fd, &self.read_fds)
}
func (self *Selector) UnRegisterWrite(fd int) {
self.unregister(fd, &self.write_fds)
}
func (self *Selector) UnRegisterError(fd int) {
self.unregister(fd, &self.err_fds)
}
func (self *Selector) Wait(timeout time.Duration) (num_ready int, err error) {
max_fd_num := 0
init_set := func(s *unix.FdSet, m map[int]bool) {
s.Zero()
for fd, enabled := range m {
if fd > -1 && enabled {
if max_fd_num < fd {
max_fd_num = fd
}
s.Set(fd)
}
}
}
init_set(&self.read_set, self.read_fds)
init_set(&self.write_set, self.write_fds)
init_set(&self.err_set, self.err_fds)
num_ready, err = Select(max_fd_num+1, &self.read_set, &self.write_set, &self.err_set, timeout)
if err == unix.EINTR {
self.read_set.Zero()
self.write_set.Zero()
self.err_set.Zero()
return 0, err
}
return
}
func (self *Selector) WaitForever() (num_ready int, err error) {
return self.Wait(-1)
}
func (self *Selector) IsReadyToRead(fd int) bool {
return fd > -1 && self.read_set.IsSet(fd)
}
func (self *Selector) IsReadyToWrite(fd int) bool {
return fd > -1 && self.write_set.IsSet(fd)
}
func (self *Selector) IsErrored(fd int) bool {
return fd > -1 && self.err_set.IsSet(fd)
}
func (self *Selector) UnregisterAll() {
self.read_fds = make(map[int]bool)
self.write_fds = make(map[int]bool)
self.err_fds = make(map[int]bool)
}
|
