mcs/class/referencesource/System.Data.Entity/System/Data/Metadata/ObjectLayer/LockedAssemblyCache.cs

   1 //---------------------------------------------------------------------
   2 // <copyright file="LockedAssemblyCache.cs" company="Microsoft">
   3 //      Copyright (c) Microsoft Corporation.  All rights reserved.
   4 // </copyright>
   5 //
   6 // @owner       Microsoft
   7 // @backupOwner Microsoft
   8 //---------------------------------------------------------------------
   9
  10 using System.Collections.Generic;
  11 using System.Diagnostics;
  12 using System.Reflection;
  13 using System.Threading;
  14
  15 namespace System.Data.Metadata.Edm
  16 {
  17     internal class LockedAssemblyCache : IDisposable
  18     {
  19         private object _lockObject;
  20         private Dictionary<Assembly, ImmutableAssemblyCacheEntry> _globalAssemblyCache;
  21         internal LockedAssemblyCache(object lockObject, Dictionary<Assembly, ImmutableAssemblyCacheEntry> globalAssemblyCache)
  22         {
  23             _lockObject = lockObject;
  24             _globalAssemblyCache = globalAssemblyCache;
  25 #pragma warning disable 0618
  26             //@
  27             Monitor.Enter(_lockObject);
  28 #pragma warning restore 0618
  29         }
  30
  31         public void Dispose()
  32         {
  33             // Technically, calling GC.SuppressFinalize is not required because the class does not
  34             // have a finalizer, but it does no harm, protects against the case where a finalizer is added
  35             // in the future, and prevents an FxCop warning.
  36             GC.SuppressFinalize(this);
  37             Monitor.Exit(_lockObject);
  38             _lockObject = null;
  39             _globalAssemblyCache = null;
  40         }
  41
  42         [Conditional("DEBUG")]
  43         private void AssertLockedByThisThread()
  44         {
  45             bool entered = false;
  46             Monitor.TryEnter(_lockObject, ref entered);
  47             if (entered)
  48             {
  49                 Monitor.Exit(_lockObject);
  50             }
  51
  52             Debug.Assert(entered, "The cache is being accessed by a thread that isn't holding the lock");
  53         }
  54
  55         internal bool TryGetValue(Assembly assembly, out ImmutableAssemblyCacheEntry cacheEntry)
  56         {
  57             AssertLockedByThisThread();
  58             return _globalAssemblyCache.TryGetValue(assembly, out cacheEntry);
  59         }
  60
  61         internal void Add(Assembly assembly, ImmutableAssemblyCacheEntry assemblyCacheEntry)
  62         {
  63             AssertLockedByThisThread();
  64             _globalAssemblyCache.Add(assembly, assemblyCacheEntry);
  65         }
  66
  67         internal void Clear()
  68         {
  69             AssertLockedByThisThread();
  70             _globalAssemblyCache.Clear();
  71         }
  72     }
  73 }