41 lines
1.1 KiB
Go
41 lines
1.1 KiB
Go
//go:build (freebsd || openbsd || netbsd || dragonfly || illumos || sqlite3_flock) && !sqlite3_nosys
|
|
|
|
package vfs
|
|
|
|
import (
|
|
"os"
|
|
"time"
|
|
|
|
"golang.org/x/sys/unix"
|
|
)
|
|
|
|
func osUnlock(file *os.File, start, len int64) _ErrorCode {
|
|
if start == 0 && len == 0 {
|
|
err := unix.Flock(int(file.Fd()), unix.LOCK_UN)
|
|
if err != nil {
|
|
return _IOERR_UNLOCK
|
|
}
|
|
}
|
|
return _OK
|
|
}
|
|
|
|
func osLock(file *os.File, how int, def _ErrorCode) _ErrorCode {
|
|
err := unix.Flock(int(file.Fd()), how)
|
|
return osLockErrorCode(err, def)
|
|
}
|
|
|
|
func osReadLock(file *os.File, _ /*start*/, _ /*len*/ int64, _ /*timeout*/ time.Duration) _ErrorCode {
|
|
return osLock(file, unix.LOCK_SH|unix.LOCK_NB, _IOERR_RDLOCK)
|
|
}
|
|
|
|
func osWriteLock(file *os.File, _ /*start*/, _ /*len*/ int64, _ /*timeout*/ time.Duration) _ErrorCode {
|
|
rc := osLock(file, unix.LOCK_EX|unix.LOCK_NB, _IOERR_LOCK)
|
|
if rc == _BUSY {
|
|
// The documentation states the lock is upgraded by releasing the previous lock,
|
|
// then acquiring the new lock.
|
|
// This is a race, so return BUSY_SNAPSHOT to ensure the transaction is aborted.
|
|
return _BUSY_SNAPSHOT
|
|
}
|
|
return rc
|
|
}
|