Class Lock

An interprocess mutex lock.

Typical use might look like:

    var result = Lock.With.NewAnonymous<string>(
        @lock: directory.MakeLock("my.lock"), 
        lockWaitTimeout: Lock.LOCK_OBTAIN_WAIT_FOREVER, 
        doBody: () =>
    {
        //... code to execute while locked ...
        return "the result";
    }).Run();

Inheritance

System.Object

Lock

Namespace: Lucene.Net.Store

Assembly: Lucene.Net.dll

Syntax

public abstract class Lock : IDisposable

Fields

LOCK_OBTAIN_WAIT_FOREVER

Pass this value to Obtain(Int64) to try forever to obtain the lock.

Declaration

public const long LOCK_OBTAIN_WAIT_FOREVER = null

Field Value

Type	Description
System.Int64

LOCK_POLL_INTERVAL

How long Obtain(Int64) waits, in milliseconds, in between attempts to acquire the lock.

Declaration

public static long LOCK_POLL_INTERVAL

Field Value

Type	Description
System.Int64

Properties

FailureReason

If a lock obtain called, this failureReason may be set with the "root cause" as to why the lock was not obtained.

Declaration

protected Exception FailureReason { get; set; }

Property Value

Type	Description
Exception

Methods

Dispose()

Releases exclusive access.

Declaration

public void Dispose()

Dispose(Boolean)

Releases exclusive access.

Declaration

protected abstract void Dispose(bool disposing)

Parameters

Type	Name	Description
System.Boolean	disposing

IsLocked()

Returns true if the resource is currently locked. Note that one must still call Obtain() before using the resource.

Declaration

public abstract bool IsLocked()

Returns

Type	Description
System.Boolean

NewAnonymous<T>(Lock, Int32, Func<T>)

Creates a new instance with the ability to specify the DoBody() method through the doBody argument

Simple example:

    var result = Lock.With.NewAnonymous<string>(
        @lock: directory.MakeLock("my.lock"), 
        lockWaitTimeout: Lock.LOCK_OBTAIN_WAIT_FOREVER, 
        doBody: () =>
    {
        //... code to execute while locked ...
        return "the result";
    }).Run();

The result of the operation is the value that is returned from doBody (i.e. () => { return "the result"; }). The type of determines the return type of the operation.

Declaration

public static Lock.With<T> NewAnonymous<T>(Lock lock, int lockWaitTimeout, Func<T> doBody)

Parameters

Type	Name	Description
Lock	lock	the Lock instance to use
System.Int32	lockWaitTimeout	length of time to wait in milliseconds or LOCK_OBTAIN_WAIT_FOREVER to retry forever
Func<T>	doBody	a delegate method that

Returns

Type	Description
Lock.With<T>	The value that is returned from the doBody delegate method (i.e. () => { return theObject; })

Type Parameters

Name	Description
T

Obtain()

Attempts to obtain exclusive access and immediately return upon success or failure. Use Dispose() to release the lock.

Declaration

public abstract bool Obtain()

Returns

Type	Description
System.Boolean	true iff exclusive access is obtained

Obtain(Int64)

Attempts to obtain an exclusive lock within amount of time given. Polls once per LOCK_POLL_INTERVAL (currently 1000) milliseconds until lockWaitTimeout is passed.

Declaration

public bool Obtain(long lockWaitTimeout)

Parameters

Type	Name	Description
System.Int64	lockWaitTimeout	length of time to wait in milliseconds or LOCK_OBTAIN_WAIT_FOREVER to retry forever

Returns

Type	Description
System.Boolean	true if lock was obtained

Exceptions

Type	Condition
LockObtainFailedException	if lock wait times out

See Also

MakeLock(System.String)