diff --git a/files_darwin.go b/files_darwin.go
index 9f14a43..919dcee 100644
--- a/files_darwin.go
+++ b/files_darwin.go
@@ -3,11 +3,81 @@
 package staros
 
 import (
+	"b612.me/stario"
 	"os"
 	"syscall"
 	"time"
 )
 
+type FileLock struct {
+	fd       int
+	filepath string
+}
+
+func (f *FileLock) openFileForLock() error {
+	fd, err := syscall.Open(f.filepath, syscall.O_CREAT|syscall.O_RDONLY, 0600)
+	if err != nil {
+		return err
+	}
+	f.filepath = f.filepath
+	f.fd = fd
+	return nil
+}
+
+func (f *FileLock) Lock(Exclusive bool) error {
+	var lockType int
+	if Exclusive {
+		lockType = syscall.LOCK_EX
+	} else {
+		lockType = syscall.LOCK_SH
+	}
+	if err := f.openFileForLock(); err != nil {
+		return err
+	}
+	return syscall.Flock(f.fd, lockType)
+}
+
+func (f *FileLock) LockNoBlocking(Exclusive bool) error {
+	var lockType int
+	if Exclusive {
+		lockType = syscall.LOCK_EX
+	} else {
+		lockType = syscall.LOCK_SH
+	}
+	if err := f.openFileForLock(); err != nil {
+		return err
+	}
+	err := syscall.Flock(f.fd, lockType|syscall.LOCK_NB)
+	if err != nil {
+		syscall.Close(f.fd)
+		if err == syscall.EWOULDBLOCK {
+			return ERR_ALREADY_LOCKED
+		}
+	}
+	return err
+}
+
+func (f *FileLock) Unlock() error {
+	err := syscall.Flock(f.fd, syscall.LOCK_UN)
+	if err != nil {
+		return err
+	}
+	return syscall.Close(f.fd)
+}
+
+func (f *FileLock) LockWithTimeout(tm time.Duration, Exclusive bool) error {
+	return stario.WaitUntilTimeout(tm, func(tmout chan struct{}) error {
+		err := f.Lock(Exclusive)
+		select {
+		case <-tmout:
+			f.Unlock()
+			return nil
+		default:
+		}
+		return err
+	})
+}
+
 func timespecToTime(ts syscall.Timespec) time.Time {
 	return time.Unix(int64(ts.Sec), int64(ts.Nsec))
 }
diff --git a/go.mod b/go.mod
index 11a6acc..819d836 100644
--- a/go.mod
+++ b/go.mod
@@ -3,8 +3,10 @@ module b612.me/staros
 go 1.16
 
 require (
-	b612.me/stario v0.0.5
+	b612.me/stario v0.0.7
 	b612.me/win32api v0.0.1
 	b612.me/wincmd v0.0.1
-	golang.org/x/sys v0.0.0-20220310020820-b874c991c1a5
+	golang.org/x/crypto v0.0.0-20220315160706-3147a52a75dd // indirect
+	golang.org/x/sys v0.0.0-20220318055525-2edf467146b5
+	golang.org/x/term v0.0.0-20210927222741-03fcf44c2211 // indirect
 )
diff --git a/go.sum b/go.sum
index 7ab30c0..6aff4da 100644
--- a/go.sum
+++ b/go.sum
@@ -1,18 +1,26 @@
 b612.me/stario v0.0.5 h1:Q1OGF+8eOoK49zMzkyh80GWaMuknhey6+PWJJL9ZuNo=
 b612.me/stario v0.0.5/go.mod h1:or4ssWcxQSjMeu+hRKEgtp0X517b3zdlEOAms8Qscvw=
+b612.me/stario v0.0.7 h1:QbQcsHCVLE6vRgVrPN4+9DGiSaC6IWdtm4ClL2tpMUg=
+b612.me/stario v0.0.7/go.mod h1:or4ssWcxQSjMeu+hRKEgtp0X517b3zdlEOAms8Qscvw=
 b612.me/win32api v0.0.1 h1:vLFB1xhO6pd9+zB2EyaapKB459Urv3v+C1YwgwOFEWo=
 b612.me/win32api v0.0.1/go.mod h1:MHu0JBQjzxQ2yxpZPUBbn5un45o67eF5iWKa4Q9e0yE=
 b612.me/wincmd v0.0.1 h1:4+RCFKHuD/JqAYsdtO6sTNKJs1nQVMQo87h6KhTJjkM=
 b612.me/wincmd v0.0.1/go.mod h1:32xTM7qWAI7jx6qwTrig05rxejSYbSp7CX5WD7qsMxY=
 golang.org/x/crypto v0.0.0-20220313003712-b769efc7c000 h1:SL+8VVnkqyshUSz5iNnXtrBQzvFF2SkROm6t5RczFAE=
 golang.org/x/crypto v0.0.0-20220313003712-b769efc7c000/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
+golang.org/x/crypto v0.0.0-20220315160706-3147a52a75dd h1:XcWmESyNjXJMLahc3mqVQJcgSTDxFxhETVlfk9uGc38=
+golang.org/x/crypto v0.0.0-20220315160706-3147a52a75dd/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
 golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220310020820-b874c991c1a5 h1:y/woIyUBFbpQGKS0u1aHF/40WUDnek3fPOyD08H5Vng=
 golang.org/x/sys v0.0.0-20220310020820-b874c991c1a5/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220318055525-2edf467146b5 h1:saXMvIOKvRFwbOMicHXr0B1uwoxq9dGmLe5ExMES6c4=
+golang.org/x/sys v0.0.0-20220318055525-2edf467146b5/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1 h1:v+OssWQX+hTHEmOBgwxdZxK4zHq3yOs8F9J7mk0PY8E=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/term v0.0.0-20210927222741-03fcf44c2211 h1:JGgROgKl9N8DuW20oFS5gxc+lE67/N3FcwmBPMe7ArY=
+golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=