From 97781d2ed116d2cd9cb870d0b84fc0ec598c9abc Mon Sep 17 00:00:00 2001 From: Alex Brainman Date: Tue, 30 Oct 2018 19:40:57 +1100 Subject: [PATCH] [release-branch.go1.11] internal/poll: advance file position in windows sendfile Some versions of Windows (Windows 10 1803) do not set file position after TransmitFile completes. So just use Seek to set file position before returning from sendfile. Fixes #27411 Change-Id: I7a49be10304b5db19dda707b13ac93d338aeb190 Reviewed-on: https://go-review.googlesource.com/131976 Reviewed-by: Brad Fitzpatrick Reviewed-by: Ian Lance Taylor Reviewed-by: Yasuhiro MATSUMOTO Run-TryBot: Brad Fitzpatrick TryBot-Result: Gobot Gobot Reviewed-on: https://go-review.googlesource.com/c/145779 Run-TryBot: Alex Brainman --- src/internal/poll/sendfile_windows.go | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/src/internal/poll/sendfile_windows.go b/src/internal/poll/sendfile_windows.go index dc93e851d6..17a3681064 100644 --- a/src/internal/poll/sendfile_windows.go +++ b/src/internal/poll/sendfile_windows.go @@ -38,5 +38,11 @@ func SendFile(fd *FD, src syscall.Handle, n int64) (int64, error) { done, err := wsrv.ExecIO(o, func(o *operation) error { return syscall.TransmitFile(o.fd.Sysfd, o.handle, o.qty, 0, &o.o, nil, syscall.TF_WRITE_BEHIND) }) + if err == nil { + // Some versions of Windows (Windows 10 1803) do not set + // file position after TransmitFile completes. + // So just use Seek to set file position. + _, err = syscall.Seek(o.handle, curpos+int64(done), 0) + } return int64(done), err } -- 2.50.0