1 files changed, 182 insertions, 0 deletions
diff --git a/gcc-4.9/libgo/go/net/fd_select.go b/gcc-4.9/libgo/go/net/fd_select.go
new file mode 100644
index 000000000..4103c57e2
--- /dev/null
+++ b/gcc-4.9/libgo/go/net/fd_select.go
@@ -0,0 +1,182 @@
+// Copyright 2010 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 select(2).
+
+package net
+
+import (
+	"errors"
+	"os"
+	"syscall"
+)
+
+type pollster struct {
+	readFds, writeFds, repeatFds *syscall.FdSet
+	maxFd                        int
+	readyReadFds, readyWriteFds  *syscall.FdSet
+	nReady                       int
+	lastFd                       int
+	closed                       bool
+}
+
+func newpollster() (p *pollster, err error) {
+	p = new(pollster)
+	p.readFds = new(syscall.FdSet)
+	p.writeFds = new(syscall.FdSet)
+	p.repeatFds = new(syscall.FdSet)
+	p.readyReadFds = new(syscall.FdSet)
+	p.readyWriteFds = new(syscall.FdSet)
+	p.maxFd = -1
+	p.nReady = 0
+	p.lastFd = 0
+	return p, nil
+}
+
+func (p *pollster) AddFD(fd int, mode int, repeat bool) (bool, error) {
+	// pollServer is locked.
+
+	if p.closed {
+		return false, errors.New("pollster closed")
+	}
+
+	if mode == 'r' {
+		syscall.FDSet(fd, p.readFds)
+	} else {
+		syscall.FDSet(fd, p.writeFds)
+	}
+
+	if repeat {
+		syscall.FDSet(fd, p.repeatFds)
+	}
+
+	if fd > p.maxFd {
+		p.maxFd = fd
+	}
+
+	return true, nil
+}
+
+func (p *pollster) DelFD(fd int, mode int) bool {
+	// pollServer is locked.
+
+	if p.closed {
+		return false
+	}
+
+	if mode == 'r' {
+		if !syscall.FDIsSet(fd, p.readFds) {
+			print("Select unexpected fd=", fd, " for read\n")
+			return false
+		}
+		syscall.FDClr(fd, p.readFds)
+	} else {
+		if !syscall.FDIsSet(fd, p.writeFds) {
+			print("Select unexpected fd=", fd, " for write\n")
+			return false
+		}
+		syscall.FDClr(fd, p.writeFds)
+	}
+
+	// Doesn't matter if not already present.
+	syscall.FDClr(fd, p.repeatFds)
+
+	// We don't worry about maxFd here.
+
+	return true
+}
+
+func (p *pollster) WaitFD(s *pollServer, nsec int64) (fd int, mode int, err error) {
+	if p.nReady == 0 {
+		var timeout *syscall.Timeval
+		var tv syscall.Timeval
+		timeout = nil
+		if nsec > 0 {
+			tv = syscall.NsecToTimeval(nsec)
+			timeout = &tv
+		}
+
+		var n int
+		var e error
+		var tmpReadFds, tmpWriteFds syscall.FdSet
+		for {
+			if p.closed {
+				return -1, 0, errors.New("pollster closed")
+			}
+
+			// Temporary syscall.FdSet's into which the values are copied
+			// because select mutates the values.
+			tmpReadFds = *p.readFds
+			tmpWriteFds = *p.writeFds
+
+			s.Unlock()
+			n, e = syscall.Select(p.maxFd+1, &tmpReadFds, &tmpWriteFds, nil, timeout)
+			s.Lock()
+
+			if e != syscall.EINTR {
+				break
+			}
+		}
+		if e == syscall.EBADF {
+			// Some file descriptor has been closed.
+			tmpReadFds = syscall.FdSet{}
+			tmpWriteFds = syscall.FdSet{}
+			n = 0
+			for i := 0; i < p.maxFd+1; i++ {
+				if syscall.FDIsSet(i, p.readFds) {
+					var s syscall.Stat_t
+					if syscall.Fstat(i, &s) == syscall.EBADF {
+						syscall.FDSet(i, &tmpReadFds)
+						n++
+					}
+				} else if syscall.FDIsSet(i, p.writeFds) {
+					var s syscall.Stat_t
+					if syscall.Fstat(i, &s) == syscall.EBADF {
+						syscall.FDSet(i, &tmpWriteFds)
+						n++
+					}
+				}
+			}
+		} else if e != nil {
+			return -1, 0, os.NewSyscallError("select", e)
+		}
+		if n == 0 {
+			return -1, 0, nil
+		}
+
+		p.nReady = n
+		*p.readyReadFds = tmpReadFds
+		*p.readyWriteFds = tmpWriteFds
+		p.lastFd = 0
+	}
+
+	flag := false
+	for i := p.lastFd; i < p.maxFd+1; i++ {
+		if syscall.FDIsSet(i, p.readyReadFds) {
+			flag = true
+			mode = 'r'
+			syscall.FDClr(i, p.readyReadFds)
+		} else if syscall.FDIsSet(i, p.readyWriteFds) {
+			flag = true
+			mode = 'w'
+			syscall.FDClr(i, p.readyWriteFds)
+		}
+		if flag {
+			if !syscall.FDIsSet(i, p.repeatFds) {
+				p.DelFD(i, mode)
+			}
+			p.nReady--
+			p.lastFd = i
+			return i, mode, nil
+		}
+	}
+
+	// Will not reach here.  Just to shut up the compiler.
+	return -1, 0, nil
+}
+
+func (p *pollster) Close() error {
+	p.closed = true
+	return nil
+}