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1 // Copyright 2013 The Go Authors. All rights reserved. | 1 // Copyright 2013 The Go Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style | 2 // Use of this source code is governed by a BSD-style |
3 // license that can be found in the LICENSE file. | 3 // license that can be found in the LICENSE file. |
4 | 4 |
5 package net | 5 package net |
6 | 6 |
7 import ( | 7 import ( |
8 "syscall" | 8 "syscall" |
9 ) | 9 ) |
10 | 10 |
11 var use_accept4 = true | 11 // Accept4() comes from Linux 2.6.28. |
| 12 // Fallback to Accept() when Accept4() returns ENOSYS. |
| 13 var useAccept4 bool = true |
12 | 14 |
13 func (fd *netFD) accept(toAddr func(syscall.Sockaddr) Addr) (netfd *netFD, err e
rror) { | 15 func (fd *netFD) accept(toAddr func(syscall.Sockaddr) Addr) (netfd *netFD, err e
rror) { |
14 if err := fd.incref(false); err != nil { | 16 if err := fd.incref(false); err != nil { |
15 return nil, err | 17 return nil, err |
16 } | 18 } |
17 defer fd.decref() | 19 defer fd.decref() |
18 | 20 |
| 21 accept4 := useAccept4 |
| 22 |
19 // See ../syscall/exec_unix.go for description of ForkLock. | 23 // See ../syscall/exec_unix.go for description of ForkLock. |
20 // It is okay to hold the lock across syscall.Accept | 24 // It is okay to hold the lock across syscall.Accept |
21 // because we have put fd.sysfd into non-blocking mode. | 25 // because we have put fd.sysfd into non-blocking mode. |
22 var s int | 26 var s int |
23 var rsa syscall.Sockaddr | 27 var rsa syscall.Sockaddr |
24 for { | 28 for { |
25 » » if use_accept4 { | 29 » » if accept4 { |
26 » » » s, rsa, err = syscall.Accept4(fd.sysfd, syscall.SOCK_CLO
EXEC) | 30 » » » s, rsa, err = syscall.Accept4(fd.sysfd, syscall.SOCK_CLO
EXEC|syscall.SOCK_NONBLOCK) |
27 if err == syscall.ENOSYS { | 31 if err == syscall.ENOSYS { |
28 » » » » use_accept4 = false | 32 » » » » accept4 = false |
| 33 » » » » useAccept4 = false |
29 continue | 34 continue |
30 } | 35 } |
31 } else { | 36 } else { |
32 syscall.ForkLock.RLock() | 37 syscall.ForkLock.RLock() |
33 s, rsa, err = syscall.Accept(fd.sysfd) | 38 s, rsa, err = syscall.Accept(fd.sysfd) |
34 if err == nil { | 39 if err == nil { |
35 syscall.CloseOnExec(s) | 40 syscall.CloseOnExec(s) |
36 } | 41 } |
37 syscall.ForkLock.RUnlock() | 42 syscall.ForkLock.RUnlock() |
38 } | 43 } |
39 if err != nil { | 44 if err != nil { |
40 if err == syscall.EAGAIN { | 45 if err == syscall.EAGAIN { |
41 if err = fd.pollServer.WaitRead(fd); err == nil
{ | 46 if err = fd.pollServer.WaitRead(fd); err == nil
{ |
42 continue | 47 continue |
43 } | 48 } |
44 } else if err == syscall.ECONNABORTED { | 49 } else if err == syscall.ECONNABORTED { |
45 // This means that a socket on the listen queue
was closed | 50 // This means that a socket on the listen queue
was closed |
46 // before we Accept()ed it; it's a silly error,
so try again. | 51 // before we Accept()ed it; it's a silly error,
so try again. |
47 continue | 52 continue |
48 } | 53 } |
49 return nil, &OpError{"accept", fd.net, fd.laddr, err} | 54 return nil, &OpError{"accept", fd.net, fd.laddr, err} |
50 } | 55 } |
51 break | 56 break |
52 } | 57 } |
53 | 58 |
54 » if netfd, err = newFD(s, fd.family, fd.sotype, fd.net); err != nil { | 59 » if !accept4 { |
55 » » closesocket(s) | 60 » » if err = syscall.SetNonblock(s, true); err != nil { |
56 » » return nil, err | 61 » » » closesocket(s) |
| 62 » » » return nil, err |
| 63 » » } |
57 } | 64 } |
| 65 netfd = newFD(s, fd.family, fd.sotype, fd.net) |
58 lsa, _ := syscall.Getsockname(netfd.sysfd) | 66 lsa, _ := syscall.Getsockname(netfd.sysfd) |
59 netfd.setAddr(toAddr(lsa), toAddr(rsa)) | 67 netfd.setAddr(toAddr(lsa), toAddr(rsa)) |
60 return netfd, nil | 68 return netfd, nil |
61 } | 69 } |
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