72 lines
1.6 KiB
Go
72 lines
1.6 KiB
Go
//go:build !(sqlite3_flock || sqlite3_nosys)
|
|
|
|
package vfs
|
|
|
|
import (
|
|
"math/rand"
|
|
"os"
|
|
"time"
|
|
|
|
"golang.org/x/sys/unix"
|
|
)
|
|
|
|
func osSync(file *os.File, _ /*fullsync*/, _ /*dataonly*/ bool) error {
|
|
// SQLite trusts Linux's fdatasync for all fsync's.
|
|
return unix.Fdatasync(int(file.Fd()))
|
|
}
|
|
|
|
func osAllocate(file *os.File, size int64) error {
|
|
if size == 0 {
|
|
return nil
|
|
}
|
|
return unix.Fallocate(int(file.Fd()), 0, 0, size)
|
|
}
|
|
|
|
func osUnlock(file *os.File, start, len int64) _ErrorCode {
|
|
err := unix.FcntlFlock(file.Fd(), unix.F_OFD_SETLK, &unix.Flock_t{
|
|
Type: unix.F_UNLCK,
|
|
Start: start,
|
|
Len: len,
|
|
})
|
|
if err != nil {
|
|
return _IOERR_UNLOCK
|
|
}
|
|
return _OK
|
|
}
|
|
|
|
func osLock(file *os.File, typ int16, start, len int64, timeout time.Duration, def _ErrorCode) _ErrorCode {
|
|
lock := unix.Flock_t{
|
|
Type: typ,
|
|
Start: start,
|
|
Len: len,
|
|
}
|
|
var err error
|
|
switch {
|
|
case timeout == 0:
|
|
err = unix.FcntlFlock(file.Fd(), unix.F_OFD_SETLK, &lock)
|
|
case timeout < 0:
|
|
err = unix.FcntlFlock(file.Fd(), unix.F_OFD_SETLKW, &lock)
|
|
default:
|
|
before := time.Now()
|
|
for {
|
|
err = unix.FcntlFlock(file.Fd(), unix.F_OFD_SETLK, &lock)
|
|
if errno, _ := err.(unix.Errno); errno != unix.EAGAIN {
|
|
break
|
|
}
|
|
if timeout < time.Since(before) {
|
|
break
|
|
}
|
|
time.Sleep(time.Duration(rand.Int63n(int64(time.Millisecond))))
|
|
}
|
|
}
|
|
return osLockErrorCode(err, def)
|
|
}
|
|
|
|
func osReadLock(file *os.File, start, len int64, timeout time.Duration) _ErrorCode {
|
|
return osLock(file, unix.F_RDLCK, start, len, timeout, _IOERR_RDLOCK)
|
|
}
|
|
|
|
func osWriteLock(file *os.File, start, len int64, timeout time.Duration) _ErrorCode {
|
|
return osLock(file, unix.F_WRLCK, start, len, timeout, _IOERR_LOCK)
|
|
}
|