Added runtime.KeepAlive for the new stricter 1.8 GC

Signed-off-by: Darren Stahl <darst@microsoft.com>

backup.go

@@ -185,7 +185,6 @@ type BackupFileReader struct {
 // Read will attempt to read the security descriptor of the file.
 func NewBackupFileReader(f *os.File, includeSecurity bool) *BackupFileReader {
 	r := &BackupFileReader{f, includeSecurity, 0}
-	runtime.SetFinalizer(r, func(r *BackupFileReader) { r.Close() })
 	return r
 }
 
@@ -196,6 +195,7 @@ func (r *BackupFileReader) Read(b []byte) (int, error) {
 	if err != nil {
 		return 0, &os.PathError{"BackupRead", r.f.Name(), err}
 	}
+	runtime.KeepAlive(r.f)
 	if bytesRead == 0 {
 		return 0, io.EOF
 	}
@@ -207,6 +207,7 @@ func (r *BackupFileReader) Read(b []byte) (int, error) {
 func (r *BackupFileReader) Close() error {
 	if r.ctx != 0 {
 		backupRead(syscall.Handle(r.f.Fd()), nil, nil, true, false, &r.ctx)
+		runtime.KeepAlive(r.f)
 		r.ctx = 0
 	}
 	return nil
@@ -223,7 +224,6 @@ type BackupFileWriter struct {
 // Write() will attempt to restore the security descriptor from the stream.
 func NewBackupFileWriter(f *os.File, includeSecurity bool) *BackupFileWriter {
 	w := &BackupFileWriter{f, includeSecurity, 0}
-	runtime.SetFinalizer(w, func(w *BackupFileWriter) { w.Close() })
 	return w
 }
 
@@ -234,6 +234,7 @@ func (w *BackupFileWriter) Write(b []byte) (int, error) {
 	if err != nil {
 		return 0, &os.PathError{"BackupWrite", w.f.Name(), err}
 	}
+	runtime.KeepAlive(w.f)
 	if int(bytesWritten) != len(b) {
 		return int(bytesWritten), errors.New("not all bytes could be written")
 	}
@@ -245,6 +246,7 @@ func (w *BackupFileWriter) Write(b []byte) (int, error) {
 func (w *BackupFileWriter) Close() error {
 	if w.ctx != 0 {
 		backupWrite(syscall.Handle(w.f.Fd()), nil, nil, true, false, &w.ctx)
+		runtime.KeepAlive(w.f)
 		w.ctx = 0
 	}
 	return nil

file.go

@@ -79,7 +79,6 @@ func makeWin32File(h syscall.Handle) (*win32File, error) {
 	if err != nil {
 		return nil, err
 	}
-	runtime.SetFinalizer(f, (*win32File).closeHandle)
 	return f, nil
 }
 
@@ -103,7 +102,6 @@ func (f *win32File) closeHandle() {
 // Close closes a win32File.
 func (f *win32File) Close() error {
 	f.closeHandle()
-	runtime.SetFinalizer(f, nil)
 	return nil
 }
 
@@ -166,6 +164,12 @@ func (f *win32File) asyncIo(c *ioOperation, deadline time.Time, bytes uint32, er
 		if wait {
 			r = <-c.ch
 		}
+
+		// runtime.KeepAlive is needed, as c is passed via native
+		// code to ioCompletionProcessor, c must remain alive
+		// until the channel read is complete.
+		runtime.KeepAlive(c)
+
 		err = r.err
 		if err == syscall.ERROR_OPERATION_ABORTED {
 			if f.closing {
@@ -188,6 +192,7 @@ func (f *win32File) Read(b []byte) (int, error) {
 	var bytes uint32
 	err = syscall.ReadFile(f.handle, b, &bytes, &c.o)
 	n, err := f.asyncIo(c, f.readDeadline, bytes, err)
+	runtime.KeepAlive(b)
 
 	// Handle EOF conditions.
 	if err == nil && n == 0 && len(b) != 0 {
@@ -207,7 +212,9 @@ func (f *win32File) Write(b []byte) (int, error) {
 	}
 	var bytes uint32
 	err = syscall.WriteFile(f.handle, b, &bytes, &c.o)
-	return f.asyncIo(c, f.writeDeadline, bytes, err)
+	n, err := f.asyncIo(c, f.writeDeadline, bytes, err)
+	runtime.KeepAlive(b)
+	return n, err
 }
 
 func (f *win32File) SetReadDeadline(t time.Time) error {
@@ -221,5 +228,6 @@ func (f *win32File) SetWriteDeadline(t time.Time) error {
 }
 
 func (f *win32File) Flush() error {
-	return syscall.FlushFileBuffers(f.handle)
+	err := syscall.FlushFileBuffers(f.handle)
+	return err
 }

fileinfo.go

@@ -4,6 +4,7 @@ package winio
 
 import (
 	"os"
+	"runtime"
 	"syscall"
 	"unsafe"
 )
@@ -28,6 +29,7 @@ func GetFileBasicInfo(f *os.File) (*FileBasicInfo, error) {
 	if err := getFileInformationByHandleEx(syscall.Handle(f.Fd()), fileBasicInfo, (*byte)(unsafe.Pointer(bi)), uint32(unsafe.Sizeof(*bi))); err != nil {
 		return nil, &os.PathError{Op: "GetFileInformationByHandleEx", Path: f.Name(), Err: err}
 	}
+	runtime.KeepAlive(f)
 	return bi, nil
 }
 
@@ -36,6 +38,7 @@ func SetFileBasicInfo(f *os.File, bi *FileBasicInfo) error {
 	if err := setFileInformationByHandle(syscall.Handle(f.Fd()), fileBasicInfo, (*byte)(unsafe.Pointer(bi)), uint32(unsafe.Sizeof(*bi))); err != nil {
 		return &os.PathError{Op: "SetFileInformationByHandle", Path: f.Name(), Err: err}
 	}
+	runtime.KeepAlive(f)
 	return nil
 }
 
@@ -52,5 +55,6 @@ func GetFileID(f *os.File) (*FileIDInfo, error) {
 	if err := getFileInformationByHandleEx(syscall.Handle(f.Fd()), fileIDInfo, (*byte)(unsafe.Pointer(fileID)), uint32(unsafe.Sizeof(*fileID))); err != nil {
 		return nil, &os.PathError{Op: "GetFileInformationByHandleEx", Path: f.Name(), Err: err}
 	}
+	runtime.KeepAlive(f)
 	return fileID, nil
 }

pipe.go

@@ -2,6 +2,9 @@
 
 package winio
 
+// #include <stdlib.h>
+import "C"
+
 import (
 	"errors"
 	"io"
@@ -21,7 +24,7 @@ import (
 
 type securityAttributes struct {
 	Length             uint32
-	SecurityDescriptor *byte
+	SecurityDescriptor unsafe.Pointer
 	InheritHandle      uint32
 }
 
@@ -231,12 +234,13 @@ func makeServerPipeHandle(path string, securityDescriptor []byte, c *PipeConfig,
 		mode |= cPIPE_TYPE_MESSAGE
 	}
 
-	var sa securityAttributes
-	sa.Length = uint32(unsafe.Sizeof(sa))
+	sa := &securityAttributes{}
+	sa.Length = uint32(unsafe.Sizeof(*sa))
 	if securityDescriptor != nil {
-		sa.SecurityDescriptor = &securityDescriptor[0]
+		sa.SecurityDescriptor = C.CBytes(securityDescriptor)
+		defer C.free(sa.SecurityDescriptor)
 	}
-	h, err := createNamedPipe(path, flags, mode, cPIPE_UNLIMITED_INSTANCES, uint32(c.OutputBufferSize), uint32(c.InputBufferSize), 0, &sa)
+	h, err := createNamedPipe(path, flags, mode, cPIPE_UNLIMITED_INSTANCES, uint32(c.OutputBufferSize), uint32(c.InputBufferSize), 0, sa)
 	if err != nil {
 		return 0, &os.PathError{Op: "open", Path: path, Err: err}
 	}