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| author | qmuntal <quimmuntal@gmail.com> | 2025-08-19 13:00:02 +0200 |
|---|---|---|
| committer | Quim Muntal <quimmuntal@gmail.com> | 2025-08-20 10:33:51 -0700 |
| commit | 509d5f647ffc413bd874c2e2bf6d1b33f9bc0ac2 (patch) | |
| tree | c566db74cd33acb90133e0d2021da41b06f18c39 /src/internal/poll | |
| parent | 853fc1273912b020e428c77d35e525c9225fd51e (diff) | |
| download | go-509d5f647ffc413bd874c2e2bf6d1b33f9bc0ac2.tar.xz | |
internal/poll: don't call Seek for overlapped Windows handles
Overlapped handles don't have the file pointer updated when performing
I/O operations, so there is no need to call FD.Seek to reset the file
pointer.
Also, some overlapped file handles don't support seeking. See #74951.
Fixes #74951.
Change-Id: I0edd53beed7d3862730f3b2ed5fe9ba490e66c06
Reviewed-on: https://go-review.googlesource.com/c/go/+/697295
Reviewed-by: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Diffstat (limited to 'src/internal/poll')
| -rw-r--r-- | src/internal/poll/fd_windows.go | 40 |
1 files changed, 30 insertions, 10 deletions
diff --git a/src/internal/poll/fd_windows.go b/src/internal/poll/fd_windows.go index 52571d5fe0..ebb2abcbf8 100644 --- a/src/internal/poll/fd_windows.go +++ b/src/internal/poll/fd_windows.go @@ -622,12 +622,22 @@ func (fd *FD) Pread(b []byte, off int64) (int, error) { fd.l.Lock() defer fd.l.Unlock() - curoffset, err := syscall.Seek(fd.Sysfd, 0, io.SeekCurrent) - if err != nil { - return 0, err + if fd.isBlocking { + curoffset, err := syscall.Seek(fd.Sysfd, 0, io.SeekCurrent) + if err != nil { + return 0, err + } + defer syscall.Seek(fd.Sysfd, curoffset, io.SeekStart) + defer fd.setOffset(curoffset) + } else { + // Overlapped handles don't have the file pointer updated + // when performing I/O operations, so there is no need to + // call Seek to reset the file pointer. + // Also, some overlapped file handles don't support seeking. + // See https://go.dev/issues/74951. + curoffset := fd.offset + defer fd.setOffset(curoffset) } - defer syscall.Seek(fd.Sysfd, curoffset, io.SeekStart) - defer fd.setOffset(curoffset) o := &fd.rop o.InitBuf(b) fd.setOffset(off) @@ -847,12 +857,22 @@ func (fd *FD) Pwrite(buf []byte, off int64) (int, error) { fd.l.Lock() defer fd.l.Unlock() - curoffset, err := syscall.Seek(fd.Sysfd, 0, io.SeekCurrent) - if err != nil { - return 0, err + if fd.isBlocking { + curoffset, err := syscall.Seek(fd.Sysfd, 0, io.SeekCurrent) + if err != nil { + return 0, err + } + defer syscall.Seek(fd.Sysfd, curoffset, io.SeekStart) + defer fd.setOffset(curoffset) + } else { + // Overlapped handles don't have the file pointer updated + // when performing I/O operations, so there is no need to + // call Seek to reset the file pointer. + // Also, some overlapped file handles don't support seeking. + // See https://go.dev/issues/74951. + curoffset := fd.offset + defer fd.setOffset(curoffset) } - defer syscall.Seek(fd.Sysfd, curoffset, io.SeekStart) - defer fd.setOffset(curoffset) var ntotal int for { |