mcs/class/referencesource/System.Data/System/Data/Odbc/OdbcEnvironmentHandle.cs

   1 //------------------------------------------------------------------------------
   2 // <copyright file="OdbcEnvironmentHandle.cs" company="Microsoft">
   3 //      Copyright (c) Microsoft Corporation.  All rights reserved.
   4 // </copyright>
   5 // <owner current="true" primary="true">Microsoft</owner>
   6 // <owner current="true" primary="false">Microsoft</owner>
   7 //------------------------------------------------------------------------------
   8
   9 using System;
  10 using System.Collections;
  11 using System.ComponentModel;
  12 using System.Data;
  13 using System.Data.Common;
  14 using System.Diagnostics;
  15 using System.Globalization;
  16 using System.Runtime.InteropServices;
  17 using System.Security;
  18 using System.Security.Permissions;
  19 using System.Text;
  20 using System.Threading;
  21 using System.Runtime.Versioning;
  22
  23 namespace System.Data.Odbc {
  24
  25     sealed internal class OdbcEnvironmentHandle : OdbcHandle {
  26
  27         // SxS: this method uses SQLSetEnvAttr to setup ODBC environment handle settings. Environment handle is safe in SxS.
  28         [ResourceExposure(ResourceScope.None)]
  29         [ResourceConsumption(ResourceScope.Process, ResourceScope.Process)]
  30         internal OdbcEnvironmentHandle() : base(ODBC32.SQL_HANDLE.ENV, null) {
  31             ODBC32.RetCode retcode;
  32
  33             //Set the expected driver manager version
  34             //
  35             retcode = UnsafeNativeMethods.SQLSetEnvAttr(
  36                 this,
  37                 ODBC32.SQL_ATTR.ODBC_VERSION,
  38                 ODBC32.SQL_OV_ODBC3,
  39                 ODBC32.SQL_IS.INTEGER);
  40             // ignore retcode
  41
  42             //Turn on connection pooling
  43             //Note: the env handle controls pooling.  Only those connections created under that
  44             //handle are pooled.  So we have to keep it alive and not create a new environment
  45             //for   every connection.
  46             //
  47             retcode = UnsafeNativeMethods.SQLSetEnvAttr(
  48                 this,
  49                 ODBC32.SQL_ATTR.CONNECTION_POOLING,
  50                 ODBC32.SQL_CP_ONE_PER_HENV,
  51                 ODBC32.SQL_IS.INTEGER);
  52
  53             switch(retcode) {
  54             case ODBC32.RetCode.SUCCESS:
  55             case ODBC32.RetCode.SUCCESS_WITH_INFO:
  56                 break;
  57             default:
  58                 Dispose();
  59                 throw ODBC.CantEnableConnectionpooling(retcode);
  60             }
  61         }
  62     }
  63 }
  64