pkg/osutil: don't depend on syscall in appengine build

Dashboard app now depends on osutil through config package.
Reshuffle functions so that the package does not depend
on syscall in appengine build.

pkg/osutil/fileutil.go

@@ -8,9 +8,6 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
-	"path/filepath"
-	"strconv"
-	"syscall"
 )
 
 // CopyFile atomically copies oldFile to newFile preserving permissions and modification time.
@@ -57,51 +54,3 @@ func WriteTempFile(data []byte) (string, error) {
 	f.Close()
 	return f.Name(), nil
 }
-
-// ProcessTempDir creates a new temp dir in where and returns its path and an unique index.
-// It also cleans up old, unused temp dirs after dead processes.
-func ProcessTempDir(where string) (string, error) {
-	lk := filepath.Join(where, "instance-lock")
-	lkf, err := syscall.Open(lk, syscall.O_RDWR|syscall.O_CREAT, DefaultFilePerm)
-	if err != nil {
-		return "", err
-	}
-	defer syscall.Close(lkf)
-	if err := syscall.Flock(lkf, syscall.LOCK_EX); err != nil {
-		return "", err
-	}
-	defer syscall.Flock(lkf, syscall.LOCK_UN)
-
-	for i := 0; i < 1e3; i++ {
-		path := filepath.Join(where, fmt.Sprintf("instance-%v", i))
-		pidfile := filepath.Join(path, ".pid")
-		err := os.Mkdir(path, DefaultDirPerm)
-		if os.IsExist(err) {
-			// Try to clean up.
-			data, err := ioutil.ReadFile(pidfile)
-			if err == nil && len(data) > 0 {
-				pid, err := strconv.Atoi(string(data))
-				if err == nil && pid > 1 {
-					if err := syscall.Kill(pid, 0); err == syscall.ESRCH {
-						if os.Remove(pidfile) == nil {
-							if os.RemoveAll(path) == nil {
-								i--
-								continue
-							}
-						}
-					}
-				}
-			}
-			// If err != nil, assume that the pid file is not created yet.
-			continue
-		}
-		if err != nil {
-			return "", err
-		}
-		if err := WriteFile(pidfile, []byte(strconv.Itoa(syscall.Getpid()))); err != nil {
-			return "", err
-		}
-		return path, nil
-	}
-	return "", fmt.Errorf("too many live instances")
-}

pkg/osutil/fileutil_linux.go

@@ -1,6 +1,8 @@
 // Copyright 2017 syzkaller project authors. All rights reserved.
 // Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
 
+// +build !appengine
+
 package osutil
 
 import (

pkg/osutil/osutil.go

@@ -6,13 +6,10 @@ package osutil
 import (
 	"bytes"
 	"fmt"
-	"io"
 	"io/ioutil"
 	"os"
 	"os/exec"
-	"os/signal"
 	"path/filepath"
-	"syscall"
 	"time"
 )
 
@@ -47,15 +44,6 @@ func RunCmd(timeout time.Duration, dir, bin string, args ...string) ([]byte, err
 	return output.Bytes(), nil
 }
 
-func LongPipe() (io.ReadCloser, io.WriteCloser, error) {
-	r, w, err := os.Pipe()
-	if err != nil {
-		return nil, nil, fmt.Errorf("failed to create pipe: %v", err)
-	}
-	prolongPipe(r, w)
-	return r, w, err
-}
-
 var wd string
 
 func init() {
@@ -82,24 +70,6 @@ func IsExist(name string) bool {
 	return err == nil
 }
 
-// HandleInterrupts closes shutdown chan on first SIGINT
-// (expecting that the program will gracefully shutdown and exit)
-// and terminates the process on third SIGINT.
-func HandleInterrupts(shutdown chan struct{}) {
-	go func() {
-		c := make(chan os.Signal, 3)
-		signal.Notify(c, syscall.SIGINT)
-		<-c
-		close(shutdown)
-		fmt.Fprint(os.Stderr, "SIGINT: shutting down...\n")
-		<-c
-		fmt.Fprint(os.Stderr, "SIGINT: shutting down harder...\n")
-		<-c
-		fmt.Fprint(os.Stderr, "SIGINT: terminating\n")
-		os.Exit(int(syscall.SIGINT))
-	}()
-}
-
 // FilesExist returns true if all files exist in dir.
 // Files are assumed to be relative names in slash notation.
 func FilesExist(dir string, files []string) bool {

pkg/osutil/osutil_linux.go

@@ -1,6 +1,8 @@
 // Copyright 2017 syzkaller project authors. All rights reserved.
 // Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
 
+// +build !appengine
+
 package osutil
 
 import (

pkg/osutil/osutil_unix.go

@@ -0,0 +1,92 @@
+// Copyright 2017 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+// +build linux,!appengine darwin,!appengine
+
+package osutil
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/signal"
+	"path/filepath"
+	"strconv"
+	"syscall"
+)
+
+// ProcessTempDir creates a new temp dir in where and returns its path and an unique index.
+// It also cleans up old, unused temp dirs after dead processes.
+func ProcessTempDir(where string) (string, error) {
+	lk := filepath.Join(where, "instance-lock")
+	lkf, err := syscall.Open(lk, syscall.O_RDWR|syscall.O_CREAT, DefaultFilePerm)
+	if err != nil {
+		return "", err
+	}
+	defer syscall.Close(lkf)
+	if err := syscall.Flock(lkf, syscall.LOCK_EX); err != nil {
+		return "", err
+	}
+	defer syscall.Flock(lkf, syscall.LOCK_UN)
+
+	for i := 0; i < 1e3; i++ {
+		path := filepath.Join(where, fmt.Sprintf("instance-%v", i))
+		pidfile := filepath.Join(path, ".pid")
+		err := os.Mkdir(path, DefaultDirPerm)
+		if os.IsExist(err) {
+			// Try to clean up.
+			data, err := ioutil.ReadFile(pidfile)
+			if err == nil && len(data) > 0 {
+				pid, err := strconv.Atoi(string(data))
+				if err == nil && pid > 1 {
+					if err := syscall.Kill(pid, 0); err == syscall.ESRCH {
+						if os.Remove(pidfile) == nil {
+							if os.RemoveAll(path) == nil {
+								i--
+								continue
+							}
+						}
+					}
+				}
+			}
+			// If err != nil, assume that the pid file is not created yet.
+			continue
+		}
+		if err != nil {
+			return "", err
+		}
+		if err := WriteFile(pidfile, []byte(strconv.Itoa(syscall.Getpid()))); err != nil {
+			return "", err
+		}
+		return path, nil
+	}
+	return "", fmt.Errorf("too many live instances")
+}
+
+// HandleInterrupts closes shutdown chan on first SIGINT
+// (expecting that the program will gracefully shutdown and exit)
+// and terminates the process on third SIGINT.
+func HandleInterrupts(shutdown chan struct{}) {
+	go func() {
+		c := make(chan os.Signal, 3)
+		signal.Notify(c, syscall.SIGINT)
+		<-c
+		close(shutdown)
+		fmt.Fprint(os.Stderr, "SIGINT: shutting down...\n")
+		<-c
+		fmt.Fprint(os.Stderr, "SIGINT: shutting down harder...\n")
+		<-c
+		fmt.Fprint(os.Stderr, "SIGINT: terminating\n")
+		os.Exit(int(syscall.SIGINT))
+	}()
+}
+
+func LongPipe() (io.ReadCloser, io.WriteCloser, error) {
+	r, w, err := os.Pipe()
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to create pipe: %v", err)
+	}
+	prolongPipe(r, w)
+	return r, w, err
+}