Class JournalFileOpenLock

Namespace

OptunaSharp.Storages.Journal

Assembly

OptunaSharp.dll

Lock class for synchronizing processes for NFSv3 or later. Port of JournalFileOpenLock.

On acquiring the lock, the lock file is created with exclusive-create semantics (O_CREAT | O_EXCL). The file is deleted when the lock is released. This is the recommended lock on Windows.

public class JournalFileOpenLock : BaseJournalFileLock

Inheritance

object

BaseJournalFileLock

JournalFileOpenLock

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Constructors

JournalFileOpenLock(string, int?)

Creates a journal lock policy with optional stale-lock recovery.

public JournalFileOpenLock(string filepath, int? gracePeriod = 30)

Parameters

filepath string

The path of the file whose race condition must be protected.

gracePeriod int?

Grace period before an existing lock is forcibly released.

Exceptions

ValueError

A non-null grace period is zero or negative.

Properties

GracePeriod

Grace period before an existing lock is forcibly released.

public int? GracePeriod { get; }

Property Value

int?

Methods

Acquire()

Acquire a lock in a blocking way by creating a lock file.

public override bool Acquire()

Returns

bool

True after acquiring exclusive ownership.

Remarks

Waits out a lock path that is "delete pending" on Windows (see OptunaSharp.Storages.Journal.JournalFileLockProtocol.MaxDeniedStreakMilliseconds): a stale lock someone deletes by hand while this waits no longer kills the waiter. This departs from Optuna, whose waiter raises PermissionError there.

Exceptions

IOException

Lock creation fails for a reason other than an existing lock.

UnauthorizedAccessException

Lock-file creation is denied: off Windows on the first denial, as in Optuna; on Windows once denials have run unbroken for longer than OptunaSharp.Storages.Journal.JournalFileLockProtocol.MaxDeniedStreakMilliseconds (a lock file being deleted in place is waited out, not reported).

Release()

Release a lock by removing the created file.

public override void Release()

Exceptions

RuntimeError

The lock cannot be renamed and deleted, including when ownership was lost.