Refactor process.go for platform specific

Signed-off-by: John Howard <jhoward@microsoft.com>

runtime/process.go

@@ -8,7 +8,6 @@ import (
 	"os"
 	"path/filepath"
 	"strconv"
-	"syscall"
 	"time"
 
 	"github.com/opencontainers/specs"
@@ -122,22 +121,6 @@ func loadProcess(root, id string, c *container, s *ProcessState) (*process, erro
 	return p, nil
 }
 
-func getExitPipe(path string) (*os.File, error) {
-	if err := syscall.Mkfifo(path, 0755); err != nil && !os.IsExist(err) {
-		return nil, err
-	}
-	// add NONBLOCK in case the other side has already closed or else
-	// this function would never return
-	return os.OpenFile(path, syscall.O_RDONLY|syscall.O_NONBLOCK, 0)
-}
-
-func getControlPipe(path string) (*os.File, error) {
-	if err := syscall.Mkfifo(path, 0755); err != nil && !os.IsExist(err) {
-		return nil, err
-	}
-	return os.OpenFile(path, syscall.O_RDWR|syscall.O_NONBLOCK, 0)
-}
-
 type process struct {
 	root        string
 	id          string
@@ -190,11 +173,6 @@ func (p *process) ExitStatus() (int, error) {
 	return strconv.Atoi(string(data))
 }
 
-// Signal sends the provided signal to the process
-func (p *process) Signal(s os.Signal) error {
-	return syscall.Kill(p.pid, s.(syscall.Signal))
-}
-
 func (p *process) Spec() specs.Process {
 	return p.spec
 }

runtime/process_linux.go

@@ -0,0 +1,27 @@
+package runtime
+
+import (
+	"os"
+	"syscall"
+)
+
+func getExitPipe(path string) (*os.File, error) {
+	if err := syscall.Mkfifo(path, 0755); err != nil && !os.IsExist(err) {
+		return nil, err
+	}
+	// add NONBLOCK in case the other side has already closed or else
+	// this function would never return
+	return os.OpenFile(path, syscall.O_RDONLY|syscall.O_NONBLOCK, 0)
+}
+
+func getControlPipe(path string) (*os.File, error) {
+	if err := syscall.Mkfifo(path, 0755); err != nil && !os.IsExist(err) {
+		return nil, err
+	}
+	return os.OpenFile(path, syscall.O_RDWR|syscall.O_NONBLOCK, 0)
+}
+
+// Signal sends the provided signal to the process
+func (p *process) Signal(s os.Signal) error {
+	return syscall.Kill(p.pid, s.(syscall.Signal))
+}

runtime/process_windows.go

@@ -0,0 +1,19 @@
+package runtime
+
+import "os"
+
+// TODO Windows: Linux uses syscalls which don't map to Windows. Needs alternate mechanism
+func getExitPipe(path string) (*os.File, error) {
+	return nil, nil
+}
+
+// TODO Windows: Linux uses syscalls which don't map to Windows. Needs alternate mechanism
+func getControlPipe(path string) (*os.File, error) {
+	return nil, nil
+}
+
+// TODO Windows. Windows does not support signals. Need alternate mechanism
+// Signal sends the provided signal to the process
+func (p *process) Signal(s os.Signal) error {
+	return nil
+}