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author | Ben Cheng <bccheng@google.com> | 2013-03-28 11:14:20 -0700 |
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committer | Ben Cheng <bccheng@google.com> | 2013-03-28 12:40:33 -0700 |
commit | af0c51ac87ab2a87caa03fa108f0d164987a2764 (patch) | |
tree | 4b8b470f7c5b69642fdab8d0aa1fbc148d02196b /gcc-4.8/libgo/go/net/sendfile_freebsd.go | |
parent | d87cae247d39ebf4f5a6bf25c932a14d2fdb9384 (diff) | |
download | toolchain_gcc-af0c51ac87ab2a87caa03fa108f0d164987a2764.tar.gz toolchain_gcc-af0c51ac87ab2a87caa03fa108f0d164987a2764.tar.bz2 toolchain_gcc-af0c51ac87ab2a87caa03fa108f0d164987a2764.zip |
[GCC 4.8] Initial check-in of GCC 4.8.0
Change-Id: I0719d8a6d0f69b367a6ab6f10eb75622dbf12771
Diffstat (limited to 'gcc-4.8/libgo/go/net/sendfile_freebsd.go')
-rw-r--r-- | gcc-4.8/libgo/go/net/sendfile_freebsd.go | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/gcc-4.8/libgo/go/net/sendfile_freebsd.go b/gcc-4.8/libgo/go/net/sendfile_freebsd.go new file mode 100644 index 000000000..8008bc3b5 --- /dev/null +++ b/gcc-4.8/libgo/go/net/sendfile_freebsd.go @@ -0,0 +1,105 @@ +// Copyright 2011 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. + +package net + +import ( + "io" + "os" + "syscall" +) + +// maxSendfileSize is the largest chunk size we ask the kernel to copy +// at a time. +const maxSendfileSize int = 4 << 20 + +// sendFile copies the contents of r to c using the sendfile +// system call to minimize copies. +// +// if handled == true, sendFile returns the number of bytes copied and any +// non-EOF error. +// +// if handled == false, sendFile performed no work. +func sendFile(c *netFD, r io.Reader) (written int64, err error, handled bool) { + // FreeBSD uses 0 as the "until EOF" value. If you pass in more bytes than the + // file contains, it will loop back to the beginning ad nauseum until it's sent + // exactly the number of bytes told to. As such, we need to know exactly how many + // bytes to send. + var remain int64 = 0 + + lr, ok := r.(*io.LimitedReader) + if ok { + remain, r = lr.N, lr.R + if remain <= 0 { + return 0, nil, true + } + } + f, ok := r.(*os.File) + if !ok { + return 0, nil, false + } + + if remain == 0 { + fi, err := f.Stat() + if err != nil { + return 0, err, false + } + + remain = fi.Size() + } + + // The other quirk with FreeBSD's sendfile implementation is that it doesn't + // use the current position of the file -- if you pass it offset 0, it starts + // from offset 0. There's no way to tell it "start from current position", so + // we have to manage that explicitly. + pos, err := f.Seek(0, os.SEEK_CUR) + if err != nil { + return 0, err, false + } + + c.wio.Lock() + defer c.wio.Unlock() + if err := c.incref(false); err != nil { + return 0, err, true + } + defer c.decref() + + dst := c.sysfd + src := int(f.Fd()) + for remain > 0 { + n := maxSendfileSize + if int64(n) > remain { + n = int(remain) + } + pos1 := pos + n, err1 := syscall.Sendfile(dst, src, &pos1, n) + if n > 0 { + pos += int64(n) + written += int64(n) + remain -= int64(n) + } + if n == 0 && err1 == nil { + break + } + if err1 == syscall.EAGAIN { + if err1 = c.pollServer.WaitWrite(c); err1 == nil { + continue + } + } + if err1 == syscall.EINTR { + continue + } + if err1 != nil { + // This includes syscall.ENOSYS (no kernel + // support) and syscall.EINVAL (fd types which + // don't implement sendfile together) + err = &OpError{"sendfile", c.net, c.raddr, err1} + break + } + } + if lr != nil { + lr.N = remain + } + return written, err, written > 0 +} |