From: qmuntal Date: Tue, 16 Sep 2025 08:25:58 +0000 (+0200) Subject: internal/poll: remove buf field from operation X-Git-Tag: go1.26rc1~752 X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=690fc2fb05e720850a474c72bf3a8a9a6638cef7;p=gostls13.git internal/poll: remove buf field from operation WSASend and WSARecv functions capture the WSABuf structure before returning, so there is no need to keep a copy of it in the operation structure. Write and Read functions don't need it, they can operate directly on the byte slice. To be on the safe side, pin the input byte slice so that stack-allocated slices don't get moved while overlapped I/O is in progress. Cq-Include-Trybots: luci.golang.try:gotip-windows-amd64-longtest,gotip-windows-amd64-race Change-Id: I474bed94e11acafa0bdd8392b5dcf8993d8e1ed5 Reviewed-on: https://go-review.googlesource.com/c/go/+/704155 Reviewed-by: Junyang Shao LUCI-TryBot-Result: Go LUCI Reviewed-by: Damien Neil --- diff --git a/src/internal/poll/fd_windows.go b/src/internal/poll/fd_windows.go index dd9845d1b2..9323e49eb7 100644 --- a/src/internal/poll/fd_windows.go +++ b/src/internal/poll/fd_windows.go @@ -9,6 +9,7 @@ import ( "internal/race" "internal/syscall/windows" "io" + "runtime" "sync" "sync/atomic" "syscall" @@ -75,9 +76,6 @@ type operation struct { // fields used by runtime.netpoll runtimeCtx uintptr mode int32 - - // fields used only by net package - buf syscall.WSABuf } func (o *operation) setEvent() { @@ -107,9 +105,8 @@ func (fd *FD) overlapped(o *operation) *syscall.Overlapped { return &o.o } -func (o *operation) InitBuf(buf []byte) { - o.buf.Len = uint32(len(buf)) - o.buf.Buf = unsafe.SliceData(buf) +func newWsaBuf(b []byte) *syscall.WSABuf { + return &syscall.WSABuf{Buf: unsafe.SliceData(b), Len: uint32(len(b))} } var wsaBufsPool = sync.Pool{ @@ -362,6 +359,9 @@ type FD struct { isBlocking bool disassociated atomic.Bool + + readPinner runtime.Pinner + writePinner runtime.Pinner } // setOffset sets the offset fields of the overlapped object @@ -537,6 +537,11 @@ func (fd *FD) Read(buf []byte) (int, error) { defer fd.readUnlock() } + if len(buf) > 0 && !fd.isBlocking { + fd.readPinner.Pin(&buf[0]) + defer fd.readPinner.Unpin() + } + if len(buf) > maxRW { buf = buf[:maxRW] } @@ -547,10 +552,8 @@ func (fd *FD) Read(buf []byte) (int, error) { case kindConsole: n, err = fd.readConsole(buf) case kindFile, kindPipe: - o := &fd.rop - o.InitBuf(buf) - n, err = fd.execIO(o, func(o *operation) (qty uint32, err error) { - err = syscall.ReadFile(fd.Sysfd, unsafe.Slice(o.buf.Buf, o.buf.Len), &qty, fd.overlapped(o)) + n, err = fd.execIO(&fd.rop, func(o *operation) (qty uint32, err error) { + err = syscall.ReadFile(fd.Sysfd, buf, &qty, fd.overlapped(o)) return qty, err }) fd.addOffset(n) @@ -564,11 +567,9 @@ func (fd *FD) Read(buf []byte) (int, error) { } } case kindNet: - o := &fd.rop - o.InitBuf(buf) - n, err = fd.execIO(o, func(o *operation) (qty uint32, err error) { + n, err = fd.execIO(&fd.rop, func(o *operation) (qty uint32, err error) { var flags uint32 - err = syscall.WSARecv(fd.Sysfd, &o.buf, 1, &qty, &flags, &o.o, nil) + err = syscall.WSARecv(fd.Sysfd, newWsaBuf(buf), 1, &qty, &flags, &o.o, nil) return qty, err }) if race.Enabled { @@ -656,7 +657,7 @@ func (fd *FD) readConsole(b []byte) (int, error) { } // Pread emulates the Unix pread system call. -func (fd *FD) Pread(b []byte, off int64) (int, error) { +func (fd *FD) Pread(buf []byte, off int64) (int, error) { if fd.kind == kindPipe { // Pread does not work with pipes return 0, syscall.ESPIPE @@ -667,8 +668,13 @@ func (fd *FD) Pread(b []byte, off int64) (int, error) { } defer fd.readWriteUnlock() - if len(b) > maxRW { - b = b[:maxRW] + if len(buf) > 0 && !fd.isBlocking { + fd.readPinner.Pin(&buf[0]) + defer fd.readPinner.Unpin() + } + + if len(buf) > maxRW { + buf = buf[:maxRW] } if fd.isBlocking { @@ -687,17 +693,15 @@ func (fd *FD) Pread(b []byte, off int64) (int, error) { curoffset := fd.offset defer fd.setOffset(curoffset) } - o := &fd.rop - o.InitBuf(b) fd.setOffset(off) - n, err := fd.execIO(o, func(o *operation) (qty uint32, err error) { - err = syscall.ReadFile(fd.Sysfd, unsafe.Slice(o.buf.Buf, o.buf.Len), &qty, &o.o) + n, err := fd.execIO(&fd.rop, func(o *operation) (qty uint32, err error) { + err = syscall.ReadFile(fd.Sysfd, buf, &qty, &o.o) return qty, err }) if err == syscall.ERROR_HANDLE_EOF { err = io.EOF } - if len(b) != 0 { + if len(buf) != 0 { err = fd.eofError(n, err) } return n, err @@ -715,14 +719,18 @@ func (fd *FD) ReadFrom(buf []byte) (int, syscall.Sockaddr, error) { return 0, nil, err } defer fd.readUnlock() - o := &fd.rop - o.InitBuf(buf) + + if !fd.isBlocking { + fd.readPinner.Pin(&buf[0]) + defer fd.readPinner.Unpin() + } + rsa := wsaRsaPool.Get().(*syscall.RawSockaddrAny) defer wsaRsaPool.Put(rsa) - n, err := fd.execIO(o, func(o *operation) (qty uint32, err error) { + n, err := fd.execIO(&fd.rop, func(o *operation) (qty uint32, err error) { rsan := int32(unsafe.Sizeof(*rsa)) var flags uint32 - err = syscall.WSARecvFrom(fd.Sysfd, &o.buf, 1, &qty, &flags, rsa, &rsan, &o.o, nil) + err = syscall.WSARecvFrom(fd.Sysfd, newWsaBuf(buf), 1, &qty, &flags, rsa, &rsan, &o.o, nil) return qty, err }) err = fd.eofError(n, err) @@ -745,14 +753,18 @@ func (fd *FD) ReadFromInet4(buf []byte, sa4 *syscall.SockaddrInet4) (int, error) return 0, err } defer fd.readUnlock() - o := &fd.rop - o.InitBuf(buf) + + if !fd.isBlocking { + fd.readPinner.Pin(&buf[0]) + defer fd.readPinner.Unpin() + } + rsa := wsaRsaPool.Get().(*syscall.RawSockaddrAny) defer wsaRsaPool.Put(rsa) - n, err := fd.execIO(o, func(o *operation) (qty uint32, err error) { + n, err := fd.execIO(&fd.rop, func(o *operation) (qty uint32, err error) { rsan := int32(unsafe.Sizeof(*rsa)) var flags uint32 - err = syscall.WSARecvFrom(fd.Sysfd, &o.buf, 1, &qty, &flags, rsa, &rsan, &o.o, nil) + err = syscall.WSARecvFrom(fd.Sysfd, newWsaBuf(buf), 1, &qty, &flags, rsa, &rsan, &o.o, nil) return qty, err }) err = fd.eofError(n, err) @@ -775,14 +787,18 @@ func (fd *FD) ReadFromInet6(buf []byte, sa6 *syscall.SockaddrInet6) (int, error) return 0, err } defer fd.readUnlock() - o := &fd.rop - o.InitBuf(buf) + + if !fd.isBlocking { + fd.readPinner.Pin(&buf[0]) + defer fd.readPinner.Unpin() + } + rsa := wsaRsaPool.Get().(*syscall.RawSockaddrAny) defer wsaRsaPool.Put(rsa) - n, err := fd.execIO(o, func(o *operation) (qty uint32, err error) { + n, err := fd.execIO(&fd.rop, func(o *operation) (qty uint32, err error) { rsan := int32(unsafe.Sizeof(*rsa)) var flags uint32 - err = syscall.WSARecvFrom(fd.Sysfd, &o.buf, 1, &qty, &flags, rsa, &rsan, &o.o, nil) + err = syscall.WSARecvFrom(fd.Sysfd, newWsaBuf(buf), 1, &qty, &flags, rsa, &rsan, &o.o, nil) return qty, err }) err = fd.eofError(n, err) @@ -807,6 +823,11 @@ func (fd *FD) Write(buf []byte) (int, error) { defer fd.writeUnlock() } + if len(buf) > 0 && !fd.isBlocking { + fd.writePinner.Pin(&buf[0]) + defer fd.writePinner.Unpin() + } + var ntotal int for { max := len(buf) @@ -820,10 +841,8 @@ func (fd *FD) Write(buf []byte) (int, error) { case kindConsole: n, err = fd.writeConsole(b) case kindPipe, kindFile: - o := &fd.wop - o.InitBuf(b) - n, err = fd.execIO(o, func(o *operation) (qty uint32, err error) { - err = syscall.WriteFile(fd.Sysfd, unsafe.Slice(o.buf.Buf, o.buf.Len), &qty, fd.overlapped(o)) + n, err = fd.execIO(&fd.wop, func(o *operation) (qty uint32, err error) { + err = syscall.WriteFile(fd.Sysfd, b, &qty, fd.overlapped(o)) return qty, err }) fd.addOffset(n) @@ -831,10 +850,8 @@ func (fd *FD) Write(buf []byte) (int, error) { if race.Enabled { race.ReleaseMerge(unsafe.Pointer(&ioSync)) } - o := &fd.wop - o.InitBuf(b) - n, err = fd.execIO(o, func(o *operation) (qty uint32, err error) { - err = syscall.WSASend(fd.Sysfd, &o.buf, 1, &qty, 0, &o.o, nil) + n, err = fd.execIO(&fd.wop, func(o *operation) (qty uint32, err error) { + err = syscall.WSASend(fd.Sysfd, newWsaBuf(b), 1, &qty, 0, &o.o, nil) return qty, err }) } @@ -903,6 +920,11 @@ func (fd *FD) Pwrite(buf []byte, off int64) (int, error) { } defer fd.readWriteUnlock() + if len(buf) > 0 && !fd.isBlocking { + fd.writePinner.Pin(&buf[0]) + defer fd.writePinner.Unpin() + } + if fd.isBlocking { curoffset, err := syscall.Seek(fd.Sysfd, 0, io.SeekCurrent) if err != nil { @@ -926,12 +948,9 @@ func (fd *FD) Pwrite(buf []byte, off int64) (int, error) { if max-ntotal > maxRW { max = ntotal + maxRW } - b := buf[ntotal:max] - o := &fd.wop - o.InitBuf(b) fd.setOffset(off + int64(ntotal)) - n, err := fd.execIO(o, func(o *operation) (qty uint32, err error) { - err = syscall.WriteFile(fd.Sysfd, unsafe.Slice(o.buf.Buf, o.buf.Len), &qty, &o.o) + n, err := fd.execIO(&fd.wop, func(o *operation) (qty uint32, err error) { + err = syscall.WriteFile(fd.Sysfd, buf[ntotal:max], &qty, &o.o) return qty, err }) if n > 0 { @@ -978,25 +997,26 @@ func (fd *FD) WriteTo(buf []byte, sa syscall.Sockaddr) (int, error) { if len(buf) == 0 { // handle zero-byte payload - o := &fd.wop - o.InitBuf(buf) - n, err := fd.execIO(o, func(o *operation) (qty uint32, err error) { - err = syscall.WSASendto(fd.Sysfd, &o.buf, 1, &qty, 0, sa, &o.o, nil) + n, err := fd.execIO(&fd.wop, func(o *operation) (qty uint32, err error) { + err = syscall.WSASendto(fd.Sysfd, &syscall.WSABuf{}, 1, &qty, 0, sa, &o.o, nil) return qty, err }) return n, err } + if !fd.isBlocking { + fd.writePinner.Pin(&buf[0]) + defer fd.writePinner.Unpin() + } + ntotal := 0 for len(buf) > 0 { b := buf if len(b) > maxRW { b = b[:maxRW] } - o := &fd.wop - o.InitBuf(b) - n, err := fd.execIO(o, func(o *operation) (qty uint32, err error) { - err = syscall.WSASendto(fd.Sysfd, &o.buf, 1, &qty, 0, sa, &o.o, nil) + n, err := fd.execIO(&fd.wop, func(o *operation) (qty uint32, err error) { + err = syscall.WSASendto(fd.Sysfd, newWsaBuf(b), 1, &qty, 0, sa, &o.o, nil) return qty, err }) ntotal += int(n) @@ -1017,25 +1037,26 @@ func (fd *FD) WriteToInet4(buf []byte, sa4 *syscall.SockaddrInet4) (int, error) if len(buf) == 0 { // handle zero-byte payload - o := &fd.wop - o.InitBuf(buf) - n, err := fd.execIO(o, func(o *operation) (qty uint32, err error) { - err = windows.WSASendtoInet4(fd.Sysfd, &o.buf, 1, &qty, 0, sa4, &o.o, nil) + n, err := fd.execIO(&fd.wop, func(o *operation) (qty uint32, err error) { + err = windows.WSASendtoInet4(fd.Sysfd, &syscall.WSABuf{}, 1, &qty, 0, sa4, &o.o, nil) return qty, err }) return n, err } + if !fd.isBlocking { + fd.writePinner.Pin(&buf[0]) + defer fd.writePinner.Unpin() + } + ntotal := 0 for len(buf) > 0 { b := buf if len(b) > maxRW { b = b[:maxRW] } - o := &fd.wop - o.InitBuf(b) - n, err := fd.execIO(o, func(o *operation) (qty uint32, err error) { - err = windows.WSASendtoInet4(fd.Sysfd, &o.buf, 1, &qty, 0, sa4, &o.o, nil) + n, err := fd.execIO(&fd.wop, func(o *operation) (qty uint32, err error) { + err = windows.WSASendtoInet4(fd.Sysfd, newWsaBuf(b), 1, &qty, 0, sa4, &o.o, nil) return qty, err }) ntotal += int(n) @@ -1056,25 +1077,26 @@ func (fd *FD) WriteToInet6(buf []byte, sa6 *syscall.SockaddrInet6) (int, error) if len(buf) == 0 { // handle zero-byte payload - o := &fd.wop - o.InitBuf(buf) - n, err := fd.execIO(o, func(o *operation) (qty uint32, err error) { - err = windows.WSASendtoInet6(fd.Sysfd, &o.buf, 1, &qty, 0, sa6, &o.o, nil) + n, err := fd.execIO(&fd.wop, func(o *operation) (qty uint32, err error) { + err = windows.WSASendtoInet6(fd.Sysfd, &syscall.WSABuf{}, 1, &qty, 0, sa6, &o.o, nil) return qty, err }) return n, err } + if !fd.isBlocking { + fd.writePinner.Pin(&buf[0]) + defer fd.writePinner.Unpin() + } + ntotal := 0 for len(buf) > 0 { b := buf if len(b) > maxRW { b = b[:maxRW] } - o := &fd.wop - o.InitBuf(b) - n, err := fd.execIO(o, func(o *operation) (qty uint32, err error) { - err = windows.WSASendtoInet6(fd.Sysfd, &o.buf, 1, &qty, 0, sa6, &o.o, nil) + n, err := fd.execIO(&fd.wop, func(o *operation) (qty uint32, err error) { + err = windows.WSASendtoInet6(fd.Sysfd, newWsaBuf(b), 1, &qty, 0, sa6, &o.o, nil) return qty, err }) ntotal += int(n) @@ -1264,14 +1286,12 @@ func (fd *FD) RawRead(f func(uintptr) bool) error { // Use a zero-byte read as a way to get notified when this // socket is readable. h/t https://stackoverflow.com/a/42019668/332798 - o := &fd.rop - o.InitBuf(nil) - _, err := fd.execIO(o, func(o *operation) (qty uint32, err error) { + _, err := fd.execIO(&fd.rop, func(o *operation) (qty uint32, err error) { var flags uint32 if !fd.IsStream { flags |= windows.MSG_PEEK } - err = syscall.WSARecv(fd.Sysfd, &o.buf, 1, &qty, &flags, &o.o, nil) + err = syscall.WSARecv(fd.Sysfd, &syscall.WSABuf{}, 1, &qty, &flags, &o.o, nil) return qty, err }) if err == windows.WSAEMSGSIZE { diff --git a/src/net/tcpsock_test.go b/src/net/tcpsock_test.go index 9ed49a925b..085989c749 100644 --- a/src/net/tcpsock_test.go +++ b/src/net/tcpsock_test.go @@ -475,6 +475,9 @@ func TestTCPReadWriteAllocs(t *testing.T) { t.Skipf("not supported on %s", runtime.GOOS) } + // Optimizations are required to remove the allocs. + testenv.SkipIfOptimizationOff(t) + ln, err := Listen("tcp", "127.0.0.1:0") if err != nil { t.Fatal(err) @@ -509,7 +512,7 @@ func TestTCPReadWriteAllocs(t *testing.T) { } }) if allocs > 0 { - t.Fatalf("got %v; want 0", allocs) + t.Errorf("got %v; want 0", allocs) } var bufwrt [128]byte @@ -531,7 +534,7 @@ func TestTCPReadWriteAllocs(t *testing.T) { } }) if allocs > 0 { - t.Fatalf("got %v; want 0", allocs) + t.Errorf("got %v; want 0", allocs) } }