Merge pull request #2751 from akolb1/solaris_fix3

pkg/fileutil: add filelock support for solaris

pkg/fileutil/lock_solaris.go

@@ -0,0 +1,98 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build solaris
+
+package fileutil
+
+import (
+	"errors"
+	"os"
+	"syscall"
+)
+
+var (
+	ErrLocked = errors.New("file already locked")
+)
+
+type Lock interface {
+	Name() string
+	TryLock() error
+	Lock() error
+	Unlock() error
+	Destroy() error
+}
+
+type lock struct {
+	fd   int
+	file *os.File
+}
+
+func (l *lock) Name() string {
+	return l.file.Name()
+}
+
+// TryLock acquires exclusivity on the lock without blocking
+func (l *lock) TryLock() error {
+	var lock syscall.Flock_t
+	lock.Start = 0
+	lock.Len = 0
+	lock.Pid = 0
+	lock.Type = syscall.F_WRLCK
+	lock.Whence = 0
+	lock.Pid = 0
+	err := syscall.FcntlFlock(uintptr(l.fd), syscall.F_SETLK, &lock)
+	if err != nil && err == syscall.EAGAIN {
+		return ErrLocked
+	}
+	return err
+}
+
+// Lock acquires exclusivity on the lock without blocking
+func (l *lock) Lock() error {
+	var lock syscall.Flock_t
+	lock.Start = 0
+	lock.Len = 0
+	lock.Type = syscall.F_WRLCK
+	lock.Whence = 0
+	lock.Pid = 0
+	return syscall.FcntlFlock(uintptr(l.fd), syscall.F_SETLK, &lock)
+}
+
+// Unlock unlocks the lock
+func (l *lock) Unlock() error {
+	var lock syscall.Flock_t
+	lock.Start = 0
+	lock.Len = 0
+	lock.Type = syscall.F_UNLCK
+	lock.Whence = 0
+	err := syscall.FcntlFlock(uintptr(l.fd), syscall.F_SETLK, &lock)
+	if err != nil && err == syscall.EAGAIN {
+		return ErrLocked
+	}
+	return err
+}
+
+func (l *lock) Destroy() error {
+	return l.file.Close()
+}
+
+func NewLock(file string) (Lock, error) {
+	f, err := os.OpenFile(file, os.O_WRONLY, 0600)
+	if err != nil {
+		return nil, err
+	}
+	l := &lock{int(f.Fd()), f}
+	return l, nil
+}

pkg/fileutil/lock_unix.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// +build !windows,!plan9
+// +build !windows,!plan9,!solaris
 
 package fileutil