mcs/class/System.Web/System.Web/HttpApplicationState.cs

   1 //
   2 // System.Web.HttpApplicationState
   3 //
   4 // Author:
   5 //   Patrik Torstensson
   6 //
   7
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using System.Threading;
  30 using System.Collections.Specialized;
  31 using System.Security.Permissions;
  32
  33 namespace System.Web
  34 {
  35         // CAS - no InheritanceDemand here as the class is sealed
  36         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  37         public sealed class HttpApplicationState : NameObjectCollectionBase
  38         {
  39                 HttpStaticObjectsCollection _AppObjects;
  40                 HttpStaticObjectsCollection _SessionObjects;
  41
  42                 ReaderWriterLockSlim _Lock;
  43
  44                 internal HttpApplicationState ()
  45                 {
  46                         _Lock = new ReaderWriterLockSlim ();
  47                 }
  48
  49                 internal HttpApplicationState (HttpStaticObjectsCollection AppObj, HttpStaticObjectsCollection SessionObj)
  50                 {
  51                         _AppObjects = AppObj;
  52                         _SessionObjects = SessionObj;
  53                         _Lock = new ReaderWriterLockSlim ();
  54                 }
  55
  56                 bool IsLockHeld {
  57                         get { return _Lock.IsReadLockHeld || _Lock.IsWriteLockHeld; }
  58                 }
  59
  60                 public void Add (string name, object value)
  61                 {
  62                         bool acquired = false;
  63                         try {
  64                                 if (!IsLockHeld) {
  65                                         _Lock.EnterWriteLock ();
  66                                         acquired = true;
  67                                 }
  68                                 BaseAdd (name, value);
  69                         } finally {
  70                                 if (acquired && IsLockHeld)
  71                                         _Lock.ExitWriteLock ();
  72                         }
  73                 }
  74
  75                 public void Clear ()
  76                 {
  77                         bool acquired = false;
  78                         try {
  79                                 if (!IsLockHeld) {
  80                                         _Lock.EnterWriteLock ();
  81                                         acquired = true;
  82                                 }
  83                                 BaseClear ();
  84                         } finally {
  85                                 if (acquired && IsLockHeld)
  86                                         _Lock.ExitWriteLock ();
  87                         }
  88                 }
  89
  90                 public object Get (string name)
  91                 {
  92                         object ret = null;
  93                         bool acquired = false;
  94                         try {
  95                                 if (!IsLockHeld) {
  96                                         _Lock.EnterReadLock ();
  97                                         acquired = true;
  98                                 }
  99                                 ret = BaseGet (name);
 100                         }  finally {
 101                                 if (acquired && IsLockHeld)
 102                                         _Lock.ExitReadLock ();
 103                         }
 104
 105                         return ret;
 106                 }
 107
 108                 public object Get (int index)
 109                 {
 110                         bool acquired = false;
 111                         try {
 112                                 if (!IsLockHeld) {
 113                                         _Lock.EnterReadLock ();
 114                                         acquired = true;
 115                                 }
 116                                 return BaseGet (index);
 117                         } finally {
 118                                 if (acquired && IsLockHeld)
 119                                         _Lock.ExitReadLock ();
 120                         }
 121                 }
 122
 123                 public string GetKey (int index)
 124                 {
 125                         bool acquired = false;
 126                         try {
 127                                 if (!IsLockHeld) {
 128                                         _Lock.EnterReadLock ();
 129                                         acquired = true;
 130                                 }
 131                                 return BaseGetKey (index);
 132                         } finally {
 133                                 if (acquired && IsLockHeld)
 134                                         _Lock.ExitReadLock ();
 135                         }
 136                 }
 137
 138                 public void Lock ()
 139                 {
 140                         if (!_Lock.IsWriteLockHeld)
 141                                 _Lock.EnterWriteLock ();
 142                 }
 143
 144                 public void Remove (string name)
 145                 {
 146                         bool acquired = false;
 147                         try {
 148                                 if (!IsLockHeld) {
 149                                         _Lock.EnterWriteLock ();
 150                                         acquired = true;
 151                                 }
 152                                 BaseRemove (name);
 153                         } finally  {
 154                                 if (acquired && IsLockHeld)
 155                                         _Lock.ExitWriteLock ();
 156                         }
 157                 }
 158
 159                 public void RemoveAll ()
 160                 {
 161                         Clear ();
 162                 }
 163
 164                 public void RemoveAt (int index)
 165                 {
 166                         bool acquired = false;
 167                         try {
 168                                 if (!IsLockHeld) {
 169                                         _Lock.EnterWriteLock ();
 170                                         acquired = true;
 171                                 }
 172                                 BaseRemoveAt (index);
 173                         } finally  {
 174                                 if (acquired && IsLockHeld)
 175                                         _Lock.ExitWriteLock ();
 176                         }
 177                 }
 178
 179                 public void Set (string name, object value)
 180                 {
 181                         bool acquired = false;
 182                         try {
 183                                 if (!IsLockHeld) {
 184                                         _Lock.EnterWriteLock ();
 185                                         acquired = true;
 186                                 }
 187                                 BaseSet (name, value);
 188                         } finally  {
 189                                 if (acquired && IsLockHeld)
 190                                         _Lock.ExitWriteLock ();
 191                         }
 192                 }
 193
 194                 public void UnLock ()
 195                 {
 196                         if (_Lock.IsWriteLockHeld)
 197                                 _Lock.ExitWriteLock ();
 198                 }
 199
 200                 public string [] AllKeys {
 201                         get {
 202                                 bool acquired = false;
 203                                 try {
 204                                         if (!IsLockHeld) {
 205                                                 _Lock.EnterReadLock ();
 206                                                 acquired = true;
 207                                         }
 208                                         return BaseGetAllKeys ();
 209                                 } finally  {
 210                                         if (acquired && IsLockHeld)
 211                                                 _Lock.ExitReadLock ();
 212                                 }
 213                         }
 214                 }
 215
 216                 public HttpApplicationState Contents {
 217                         get { return this; }
 218                 }
 219
 220                 public override int Count {
 221                         get {
 222                                 bool acquired = false;
 223                                 try {
 224                                         if (!IsLockHeld) {
 225                                                 _Lock.EnterReadLock ();
 226                                                 acquired = true;
 227                                         }
 228                                         return base.Count;
 229                                 } finally  {
 230                                         if (acquired && IsLockHeld)
 231                                                 _Lock.ExitReadLock ();
 232                                 }
 233                         }
 234                 }
 235
 236                 public object this [string name] {
 237                         get { return Get (name); }
 238                         set { Set (name, value); }
 239                 }
 240
 241                 public object this [int index] {
 242                         get { return Get (index); }
 243                 }
 244
 245                 //  ASP Session based objects
 246                 internal HttpStaticObjectsCollection SessionObjects {
 247                         get {
 248                                 if (_SessionObjects == null)
 249                                         _SessionObjects = new HttpStaticObjectsCollection ();
 250
 251                                 return _SessionObjects;
 252                         }
 253                 }
 254
 255                 //  ASP App based objects
 256                 public HttpStaticObjectsCollection StaticObjects {
 257                         get {
 258                                 if (_AppObjects == null)
 259                                         _AppObjects = new HttpStaticObjectsCollection ();
 260
 261                                 return _AppObjects;
 262                         }
 263                 }
 264         }
 265 }
 266