[VOL-2235] Mocks and interfaces for rw-core
This update consists of mocks that are used by the rw-core
during unit testing. It also includes interfaces used for unit
tests.
Change-Id: I20ca1455c358113c3aa897acc6355e0ddbc614b7
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/lock_linux.go b/vendor/go.etcd.io/etcd/pkg/fileutil/lock_linux.go
new file mode 100644
index 0000000..b0abc98
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/lock_linux.go
@@ -0,0 +1,97 @@
+// Copyright 2016 The etcd Authors
+//
+// 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 linux
+
+package fileutil
+
+import (
+ "fmt"
+ "io"
+ "os"
+ "syscall"
+)
+
+// This used to call syscall.Flock() but that call fails with EBADF on NFS.
+// An alternative is lockf() which works on NFS but that call lets a process lock
+// the same file twice. Instead, use Linux's non-standard open file descriptor
+// locks which will block if the process already holds the file lock.
+//
+// constants from /usr/include/bits/fcntl-linux.h
+const (
+ F_OFD_GETLK = 37
+ F_OFD_SETLK = 37
+ F_OFD_SETLKW = 38
+)
+
+var (
+ wrlck = syscall.Flock_t{
+ Type: syscall.F_WRLCK,
+ Whence: int16(io.SeekStart),
+ Start: 0,
+ Len: 0,
+ }
+
+ linuxTryLockFile = flockTryLockFile
+ linuxLockFile = flockLockFile
+)
+
+func init() {
+ // use open file descriptor locks if the system supports it
+ getlk := syscall.Flock_t{Type: syscall.F_RDLCK}
+ if err := syscall.FcntlFlock(0, F_OFD_GETLK, &getlk); err == nil {
+ linuxTryLockFile = ofdTryLockFile
+ linuxLockFile = ofdLockFile
+ }
+}
+
+func TryLockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+ return linuxTryLockFile(path, flag, perm)
+}
+
+func ofdTryLockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+ f, err := os.OpenFile(path, flag, perm)
+ if err != nil {
+ return nil, fmt.Errorf("ofdTryLockFile failed to open %q (%v)", path, err)
+ }
+
+ flock := wrlck
+ if err = syscall.FcntlFlock(f.Fd(), F_OFD_SETLK, &flock); err != nil {
+ f.Close()
+ if err == syscall.EWOULDBLOCK {
+ err = ErrLocked
+ }
+ return nil, err
+ }
+ return &LockedFile{f}, nil
+}
+
+func LockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+ return linuxLockFile(path, flag, perm)
+}
+
+func ofdLockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+ f, err := os.OpenFile(path, flag, perm)
+ if err != nil {
+ return nil, fmt.Errorf("ofdLockFile failed to open %q (%v)", path, err)
+ }
+
+ flock := wrlck
+ err = syscall.FcntlFlock(f.Fd(), F_OFD_SETLKW, &flock)
+ if err != nil {
+ f.Close()
+ return nil, err
+ }
+ return &LockedFile{f}, nil
+}