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
|
// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build linux
package runtime
import "unsafe"
//extern epoll_create
func epollcreate(size int32) int32
//extern epoll_create1
func epollcreate1(flags int32) int32
//go:noescape
//extern epoll_ctl
func epollctl(epfd, op, fd int32, ev *epollevent) int32
//go:noescape
//extern epoll_wait
func epollwait(epfd int32, ev *epollevent, nev, timeout int32) int32
//extern __go_fcntl_uintptr
func fcntlUintptr(fd, cmd, arg uintptr) (uintptr, uintptr)
func closeonexec(fd int32) {
fcntlUintptr(uintptr(fd), _F_SETFD, _FD_CLOEXEC)
}
var (
epfd int32 = -1 // epoll descriptor
)
func netpollinit() {
epfd = epollcreate1(_EPOLL_CLOEXEC)
if epfd >= 0 {
return
}
epfd = epollcreate(1024)
if epfd >= 0 {
closeonexec(epfd)
return
}
println("netpollinit: failed to create epoll descriptor", errno())
throw("netpollinit: failed to create descriptor")
}
func netpollopen(fd uintptr, pd *pollDesc) int32 {
var ev epollevent
ev.events = _EPOLLIN | _EPOLLOUT | _EPOLLRDHUP | _EPOLLETpos
*(**pollDesc)(unsafe.Pointer(&ev.data)) = pd
if epollctl(epfd, _EPOLL_CTL_ADD, int32(fd), &ev) < 0 {
return int32(errno())
}
return 0
}
func netpollclose(fd uintptr) int32 {
var ev epollevent
if epollctl(epfd, _EPOLL_CTL_DEL, int32(fd), &ev) < 0 {
return int32(errno())
}
return 0
}
func netpollarm(pd *pollDesc, mode int) {
throw("unused")
}
// polls for ready network connections
// returns list of goroutines that become runnable
func netpoll(block bool) *g {
if epfd == -1 {
return nil
}
waitms := int32(-1)
if !block {
waitms = 0
}
var events [128]epollevent
retry:
n := epollwait(epfd, &events[0], int32(len(events)), waitms)
if n < 0 {
e := errno()
if e != _EINTR {
println("runtime: epollwait on fd", epfd, "failed with", e)
throw("epollwait failed")
}
goto retry
}
var gp guintptr
for i := int32(0); i < n; i++ {
ev := &events[i]
if ev.events == 0 {
continue
}
var mode int32
if ev.events&(_EPOLLIN|_EPOLLRDHUP|_EPOLLHUP|_EPOLLERR) != 0 {
mode += 'r'
}
if ev.events&(_EPOLLOUT|_EPOLLHUP|_EPOLLERR) != 0 {
mode += 'w'
}
if mode != 0 {
pd := *(**pollDesc)(unsafe.Pointer(&ev.data))
netpollready(&gp, pd, mode)
}
}
if block && gp == 0 {
goto retry
}
return gp.ptr()
}
|
