45 lines
889 B
Go
45 lines
889 B
Go
|
//go:build !windows
|
||
|
|
|
||
|
|
package mutex
|
||
|
|
|
||
|
|
import (
|
||
|
|
"errors"
|
||
|
|
"fmt"
|
||
|
|
"os"
|
||
|
|
"path/filepath"
|
||
|
|
|
||
|
|
"golang.org/x/sys/unix"
|
||
|
|
)
|
||
|
|
|
||
|
|
func Acquire(name string) (func(), bool, error) {
|
||
|
|
if name == "" {
|
||
|
|
return func() {}, true, nil
|
||
|
|
}
|
||
|
|
|
||
|
|
sanitized, err := sanitizeName(name)
|
||
|
|
if err != nil {
|
||
|
|
return nil, false, err
|
||
|
|
}
|
||
|
|
|
||
|
|
lockPath := filepath.Join(os.TempDir(), fmt.Sprintf("overlord-%s.lock", sanitized))
|
||
|
|
file, err := os.OpenFile(lockPath, os.O_CREATE|os.O_RDWR, 0o644)
|
||
|
|
if err != nil {
|
||
|
|
return nil, false, fmt.Errorf("open mutex file: %w", err)
|
||
|
|
}
|
||
|
|
|
||
|
|
if err := unix.Flock(int(file.Fd()), unix.LOCK_EX|unix.LOCK_NB); err != nil {
|
||
|
|
_ = file.Close()
|
||
|
|
if errors.Is(err, unix.EWOULDBLOCK) {
|
||
|
|
return func() {}, false, nil
|
||
|
|
}
|
||
|
|
return nil, false, fmt.Errorf("lock mutex file: %w", err)
|
||
|
|
}
|
||
|
|
|
||
|
|
release := func() {
|
||
|
|
_ = unix.Flock(int(file.Fd()), unix.LOCK_UN)
|
||
|
|
_ = file.Close()
|
||
|
|
}
|
||
|
|
|
||
|
|
return release, true, nil
|
||
|
|
}
|