Lucene.Net  3.0.3
Lucene.Net is a port of the Lucene search engine library, written in C# and targeted at .NET runtime users.
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ThreadLock.cs
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21 
22 using System.Threading;
23 
24 namespace Lucene.Net.Support
25 {
26  /// <summary>
27  /// Abstract base class that provides a synchronization interface
28  /// for derived lock types
29  /// </summary>
30  public abstract class ThreadLock
31  {
32  public abstract void Enter(object obj);
33  public abstract void Exit(object obj);
34 
35  private static readonly ThreadLock _nullLock = new NullThreadLock();
36  private static readonly ThreadLock _monitorLock = new MonitorThreadLock();
37 
38  /// <summary>
39  /// A ThreadLock class that actually does no locking
40  /// Used in ParallelMultiSearcher/MultiSearcher
41  /// </summary>
42  public static ThreadLock NullLock
43  {
44  get { return _nullLock; }
45  }
46 
47  /// <summary>
48  /// Wrapper class for the Monitor Enter/Exit methods
49  /// using the <see cref="ThreadLock"/> interface
50  /// </summary>
51  public static ThreadLock MonitorLock
52  {
53  get { return _monitorLock; }
54  }
55 
56  private sealed class NullThreadLock : ThreadLock
57  {
58  public override void Enter(object obj)
59  {
60  // Do nothing
61  }
62 
63  public override void Exit(object obj)
64  {
65  // Do nothing
66  }
67  }
68 
69  private sealed class MonitorThreadLock : ThreadLock
70  {
71  public override void Enter(object obj)
72  {
73  Monitor.Enter(obj);
74  }
75 
76  public override void Exit(object obj)
77  {
78  Monitor.Exit(obj);
79  }
80  }
81  }
82 }