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[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [libgo/] [go/] [net/] [fd_linux.go] - Blame information for rev 847

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// Copyright 2009 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.
 
// Waiting for FDs via epoll(7).
 
package net
 
import (
        "os"
        "syscall"
)
 
const (
        readFlags  = syscall.EPOLLIN | syscall.EPOLLRDHUP
        writeFlags = syscall.EPOLLOUT
)
 
type pollster struct {
        epfd int
 
        // Events we're already waiting for
        // Must hold pollServer lock
        events map[int]uint32
 
        // An event buffer for EpollWait.
        // Used without a lock, may only be used by WaitFD.
        waitEventBuf [10]syscall.EpollEvent
        waitEvents   []syscall.EpollEvent
 
        // An event buffer for EpollCtl, to avoid a malloc.
        // Must hold pollServer lock.
        ctlEvent syscall.EpollEvent
}
 
func newpollster() (p *pollster, err error) {
        p = new(pollster)
        if p.epfd, err = syscall.EpollCreate1(syscall.EPOLL_CLOEXEC); err != nil {
                if err != syscall.ENOSYS {
                        return nil, os.NewSyscallError("epoll_create1", err)
                }
                // The arg to epoll_create is a hint to the kernel
                // about the number of FDs we will care about.
                // We don't know, and since 2.6.8 the kernel ignores it anyhow.
                if p.epfd, err = syscall.EpollCreate(16); err != nil {
                        return nil, os.NewSyscallError("epoll_create", err)
                }
                syscall.CloseOnExec(p.epfd)
        }
        p.events = make(map[int]uint32)
        return p, nil
}
 
func (p *pollster) AddFD(fd int, mode int, repeat bool) (bool, error) {
        // pollServer is locked.
 
        var already bool
        p.ctlEvent.Fd = int32(fd)
        p.ctlEvent.Events, already = p.events[fd]
        if !repeat {
                p.ctlEvent.Events |= syscall.EPOLLONESHOT
        }
        if mode == 'r' {
                p.ctlEvent.Events |= readFlags
        } else {
                p.ctlEvent.Events |= writeFlags
        }
 
        var op int
        if already {
                op = syscall.EPOLL_CTL_MOD
        } else {
                op = syscall.EPOLL_CTL_ADD
        }
        if err := syscall.EpollCtl(p.epfd, op, fd, &p.ctlEvent); err != nil {
                return false, os.NewSyscallError("epoll_ctl", err)
        }
        p.events[fd] = p.ctlEvent.Events
        return false, nil
}
 
func (p *pollster) StopWaiting(fd int, bits uint) {
        // pollServer is locked.
 
        events, already := p.events[fd]
        if !already {
                print("Epoll unexpected fd=", fd, "\n")
                return
        }
 
        // If syscall.EPOLLONESHOT is not set, the wait
        // is a repeating wait, so don't change it.
        if events&syscall.EPOLLONESHOT == 0 {
                return
        }
 
        // Disable the given bits.
        // If we're still waiting for other events, modify the fd
        // event in the kernel.  Otherwise, delete it.
        events &= ^uint32(bits)
        if int32(events)&^syscall.EPOLLONESHOT != 0 {
                p.ctlEvent.Fd = int32(fd)
                p.ctlEvent.Events = events
                if err := syscall.EpollCtl(p.epfd, syscall.EPOLL_CTL_MOD, fd, &p.ctlEvent); err != nil {
                        print("Epoll modify fd=", fd, ": ", err.Error(), "\n")
                }
                p.events[fd] = events
        } else {
                if err := syscall.EpollCtl(p.epfd, syscall.EPOLL_CTL_DEL, fd, nil); err != nil {
                        print("Epoll delete fd=", fd, ": ", err.Error(), "\n")
                }
                delete(p.events, fd)
        }
}
 
func (p *pollster) DelFD(fd int, mode int) {
        // pollServer is locked.
 
        if mode == 'r' {
                p.StopWaiting(fd, readFlags)
        } else {
                p.StopWaiting(fd, writeFlags)
        }
 
        // Discard any queued up events.
        i := 0
        for i < len(p.waitEvents) {
                if fd == int(p.waitEvents[i].Fd) {
                        copy(p.waitEvents[i:], p.waitEvents[i+1:])
                        p.waitEvents = p.waitEvents[:len(p.waitEvents)-1]
                } else {
                        i++
                }
        }
}
 
func (p *pollster) WaitFD(s *pollServer, nsec int64) (fd int, mode int, err error) {
        for len(p.waitEvents) == 0 {
                var msec int = -1
                if nsec > 0 {
                        msec = int((nsec + 1e6 - 1) / 1e6)
                }
 
                s.Unlock()
                n, err := syscall.EpollWait(p.epfd, p.waitEventBuf[0:], msec)
                s.Lock()
 
                if err != nil {
                        if err == syscall.EAGAIN || err == syscall.EINTR {
                                continue
                        }
                        return -1, 0, os.NewSyscallError("epoll_wait", err)
                }
                if n == 0 {
                        return -1, 0, nil
                }
                p.waitEvents = p.waitEventBuf[0:n]
        }
 
        ev := &p.waitEvents[0]
        p.waitEvents = p.waitEvents[1:]
 
        fd = int(ev.Fd)
 
        if ev.Events&writeFlags != 0 {
                p.StopWaiting(fd, writeFlags)
                return fd, 'w', nil
        }
        if ev.Events&readFlags != 0 {
                p.StopWaiting(fd, readFlags)
                return fd, 'r', nil
        }
 
        // Other events are error conditions - wake whoever is waiting.
        events, _ := p.events[fd]
        if events&writeFlags != 0 {
                p.StopWaiting(fd, writeFlags)
                return fd, 'w', nil
        }
        p.StopWaiting(fd, readFlags)
        return fd, 'r', nil
}
 
func (p *pollster) Close() error {
        return os.NewSyscallError("close", syscall.Close(p.epfd))
}

Line No.	Rev	Author	Line
1	747	jeremybenn	`// Copyright 2009 The Go Authors. All rights reserved.`
2			`// Use of this source code is governed by a BSD-style`
3			`// license that can be found in the LICENSE file.`
4
5			`// Waiting for FDs via epoll(7).`
6
7			`package net`
8
9			`import (`
10			`"os"`
11			`"syscall"`
12			`)`
13
14			`const (`
15			`readFlags = syscall.EPOLLIN \| syscall.EPOLLRDHUP`
16			`writeFlags = syscall.EPOLLOUT`
17			`)`
18
19			`type pollster struct {`
20			`epfd int`
21
22			`// Events we're already waiting for`
23			`// Must hold pollServer lock`
24			`events map[int]uint32`
25
26			`// An event buffer for EpollWait.`
27			`// Used without a lock, may only be used by WaitFD.`
28			`waitEventBuf [10]syscall.EpollEvent`
29			`waitEvents []syscall.EpollEvent`
30
31			`// An event buffer for EpollCtl, to avoid a malloc.`
32			`// Must hold pollServer lock.`
33			`ctlEvent syscall.EpollEvent`
34			`}`
35
36			`func newpollster() (p *pollster, err error) {`
37			`p = new(pollster)`
38			`if p.epfd, err = syscall.EpollCreate1(syscall.EPOLL_CLOEXEC); err != nil {`
39			`if err != syscall.ENOSYS {`
40			`return nil, os.NewSyscallError("epoll_create1", err)`
41			`}`
42			`// The arg to epoll_create is a hint to the kernel`
43			`// about the number of FDs we will care about.`
44			`// We don't know, and since 2.6.8 the kernel ignores it anyhow.`
45			`if p.epfd, err = syscall.EpollCreate(16); err != nil {`
46			`return nil, os.NewSyscallError("epoll_create", err)`
47			`}`
48			`syscall.CloseOnExec(p.epfd)`
49			`}`
50			`p.events = make(map[int]uint32)`
51			`return p, nil`
52			`}`
53
54			`func (p *pollster) AddFD(fd int, mode int, repeat bool) (bool, error) {`
55			`// pollServer is locked.`
56
57			`var already bool`
58			`p.ctlEvent.Fd = int32(fd)`
59			`p.ctlEvent.Events, already = p.events[fd]`
60			`if !repeat {`
61			`p.ctlEvent.Events \|= syscall.EPOLLONESHOT`
62			`}`
63			`if mode == 'r' {`
64			`p.ctlEvent.Events \|= readFlags`
65			`} else {`
66			`p.ctlEvent.Events \|= writeFlags`
67			`}`
68
69			`var op int`
70			`if already {`
71			`op = syscall.EPOLL_CTL_MOD`
72			`} else {`
73			`op = syscall.EPOLL_CTL_ADD`
74			`}`
75			`if err := syscall.EpollCtl(p.epfd, op, fd, &p.ctlEvent); err != nil {`
76			`return false, os.NewSyscallError("epoll_ctl", err)`
77			`}`
78			`p.events[fd] = p.ctlEvent.Events`
79			`return false, nil`
80			`}`
81
82			`func (p *pollster) StopWaiting(fd int, bits uint) {`
83			`// pollServer is locked.`
84
85			`events, already := p.events[fd]`
86			`if !already {`
87			`print("Epoll unexpected fd=", fd, "\n")`
88			`return`
89			`}`
90
91			`// If syscall.EPOLLONESHOT is not set, the wait`
92			`// is a repeating wait, so don't change it.`
93			`if events&syscall.EPOLLONESHOT == 0 {`
94			`return`
95			`}`
96
97			`// Disable the given bits.`
98			`// If we're still waiting for other events, modify the fd`
99			`// event in the kernel. Otherwise, delete it.`
100			`events &= ^uint32(bits)`
101			`if int32(events)&^syscall.EPOLLONESHOT != 0 {`
102			`p.ctlEvent.Fd = int32(fd)`
103			`p.ctlEvent.Events = events`
104			`if err := syscall.EpollCtl(p.epfd, syscall.EPOLL_CTL_MOD, fd, &p.ctlEvent); err != nil {`
105			`print("Epoll modify fd=", fd, ": ", err.Error(), "\n")`
106			`}`
107			`p.events[fd] = events`
108			`} else {`
109			`if err := syscall.EpollCtl(p.epfd, syscall.EPOLL_CTL_DEL, fd, nil); err != nil {`
110			`print("Epoll delete fd=", fd, ": ", err.Error(), "\n")`
111			`}`
112			`delete(p.events, fd)`
113			`}`
114			`}`
115
116			`func (p *pollster) DelFD(fd int, mode int) {`
117			`// pollServer is locked.`
118
119			`if mode == 'r' {`
120			`p.StopWaiting(fd, readFlags)`
121			`} else {`
122			`p.StopWaiting(fd, writeFlags)`
123			`}`
124
125			`// Discard any queued up events.`
126			`i := 0`
127			`for i < len(p.waitEvents) {`
128			`if fd == int(p.waitEvents[i].Fd) {`
129			`copy(p.waitEvents[i:], p.waitEvents[i+1:])`
130			`p.waitEvents = p.waitEvents[:len(p.waitEvents)-1]`
131			`} else {`
132			`i++`
133			`}`
134			`}`
135			`}`
136
137			`func (p pollster) WaitFD(s pollServer, nsec int64) (fd int, mode int, err error) {`
138			`for len(p.waitEvents) == 0 {`
139			`var msec int = -1`
140			`if nsec > 0 {`
141			`msec = int((nsec + 1e6 - 1) / 1e6)`
142			`}`
143
144			`s.Unlock()`
145			`n, err := syscall.EpollWait(p.epfd, p.waitEventBuf[0:], msec)`
146			`s.Lock()`
147
148			`if err != nil {`
149			`if err == syscall.EAGAIN \|\| err == syscall.EINTR {`
150			`continue`
151			`}`
152			`return -1, 0, os.NewSyscallError("epoll_wait", err)`
153			`}`
154			`if n == 0 {`
155			`return -1, 0, nil`
156			`}`
157			`p.waitEvents = p.waitEventBuf[0:n]`
158			`}`
159
160			`ev := &p.waitEvents[0]`
161			`p.waitEvents = p.waitEvents[1:]`
162
163			`fd = int(ev.Fd)`
164
165			`if ev.Events&writeFlags != 0 {`
166			`p.StopWaiting(fd, writeFlags)`
167			`return fd, 'w', nil`
168			`}`
169			`if ev.Events&readFlags != 0 {`
170			`p.StopWaiting(fd, readFlags)`
171			`return fd, 'r', nil`
172			`}`
173
174			`// Other events are error conditions - wake whoever is waiting.`
175			`events, _ := p.events[fd]`
176			`if events&writeFlags != 0 {`
177			`p.StopWaiting(fd, writeFlags)`
178			`return fd, 'w', nil`
179			`}`
180			`p.StopWaiting(fd, readFlags)`
181			`return fd, 'r', nil`
182			`}`
183
184			`func (p *pollster) Close() error {`
185			`return os.NewSyscallError("close", syscall.Close(p.epfd))`
186			`}`

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[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [libgo/] [go/] [net/] [fd_linux.go] - Blame information for rev 847