mirror of
https://github.com/prometheus/prometheus.git
synced 2024-12-26 22:19:40 -08:00
baca6faa1c
This mimics the locking leveldb is performing anyway. Advantages of doing it separately: - Should we ever replace the leveldb implementation by one without double-start protection, we are still good. - In contrast to leveldb, the new code creates a meaningful error message.
47 lines
718 B
Go
47 lines
718 B
Go
// +build solaris
|
|
|
|
package flock
|
|
|
|
import (
|
|
"os"
|
|
"syscall"
|
|
)
|
|
|
|
type unixLock struct {
|
|
f *os.File
|
|
}
|
|
|
|
func (l *unixLock) Release() error {
|
|
if err := l.set(false); err != nil {
|
|
return err
|
|
}
|
|
return l.f.Close()
|
|
}
|
|
|
|
func (l *unixLock) set(lock bool) error {
|
|
flock := syscall.Flock_t{
|
|
Type: syscall.F_UNLCK,
|
|
Start: 0,
|
|
Len: 0,
|
|
Whence: 1,
|
|
}
|
|
if lock {
|
|
flock.Type = syscall.F_WRLCK
|
|
}
|
|
return syscall.FcntlFlock(l.f.Fd(), syscall.F_SETLK, &flock)
|
|
}
|
|
|
|
func newLock(fileName string) (Releaser, error) {
|
|
f, err := os.OpenFile(fileName, os.O_RDWR|os.O_CREATE, 0644)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
l := &unixLock{f}
|
|
err = l.set(true)
|
|
if err != nil {
|
|
f.Close()
|
|
return nil, err
|
|
}
|
|
return l, nil
|
|
}
|