From 13a2f533e0d9ef715acbdcaf09d983b81e3728f7 Mon Sep 17 00:00:00 2001 From: Alex Brainman Date: Sun, 26 Aug 2018 16:45:10 +1000 Subject: [PATCH] [release-branch.go1.10] 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. Updates #25722 Fixes #27419 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 (cherry picked from commit 8359b5e134052db0e5f1bc2257d496b0a81aa4fb) Reviewed-on: https://go-review.googlesource.com/c/146779 Run-TryBot: Ian Lance Taylor --- 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