class/IBM.Data.DB2/IBM.Data.DB2/DB2Environment.cs

   1
   2 //
   3 // Permission is hereby granted, free of charge, to any person obtaining
   4 // a copy of this software and associated documentation files (the
   5 // "Software"), to deal in the Software without restriction, including
   6 // without limitation the rights to use, copy, modify, merge, publish,
   7 // distribute, sublicense, and/or sell copies of the Software, and to
   8 // permit persons to whom the Software is furnished to do so, subject to
   9 // the following conditions:
  10 //
  11 // The above copyright notice and this permission notice shall be
  12 // included in all copies or substantial portions of the Software.
  13 //
  14 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  15 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  16 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  17 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  18 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  19 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  20 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  21 //
  22 using System;
  23 using System.Collections;
  24
  25 namespace IBM.Data.DB2
  26 {
  27
  28         internal sealed class DB2Environment : IDisposable
  29         {
  30                 volatile static DB2Environment environment;
  31                 static readonly object lockobj = new object ();
  32                 internal Hashtable connectionPools;
  33                 internal IntPtr penvHandle = IntPtr.Zero;
  34
  35                 private DB2Environment()
  36                 {
  37                         connectionPools = Hashtable.Synchronized(new Hashtable());
  38
  39                         //                      short sqlRet = DB2CLIWrapper.SQLAllocHandle(DB2Constants.SQL_HANDLE_ENV, IntPtr.Zero, ref penvHandle);
  40                         short sqlRet = DB2CLIWrapper.Initialize(ref penvHandle);
  41                         DB2ClientUtils.DB2CheckReturn(sqlRet, 0, IntPtr.Zero, "Unable to allocate Environment handle.", null);
  42
  43                         // SQLSetEnvAttr( hEnv=0:1, fAttribute=SQL_ATTR_APP_TYPE 2473, vParam=4, cbParam=0 )    // 4=ADO.NET apptype????
  44                         // SQLSetEnvAttr( hEnv=0:1, fAttribute=SQL_ATTR_OUTPUT_NTS 10001, vParam=0, cbParam=0 ) // strings not 0-terminated
  45                 }
  46
  47                 public static DB2Environment Instance
  48                 {
  49                         get
  50                         {
  51                                 if(environment == null)
  52                                 {
  53                                         lock(lockobj)
  54                                         {
  55                                                 if(environment == null)
  56                                                 {
  57                                                         environment = new DB2Environment();
  58                                                 }
  59                                         }
  60                                 }
  61                                 return environment;
  62                         }
  63                 }
  64                 #region IDisposable Members
  65
  66                 bool disposed;
  67                 public void Dispose()
  68                 {
  69                         Dispose(true);
  70                         GC.SuppressFinalize(this);
  71                 }
  72
  73                 public void Dispose(bool disposing)
  74                 {
  75                         if(disposed)
  76                         {
  77                                 DB2CLIWrapper.SQLFreeHandle(DB2Constants.SQL_HANDLE_ENV, penvHandle);
  78                                 environment = null;
  79                         }
  80                         disposed = true;
  81                 }
  82
  83                 ~DB2Environment()
  84                 {
  85                         Dispose(false);
  86                 }
  87
  88                 #endregion
  89         }
  90
  91 }