mcs/class/referencesource/System.Web/Util/StopListeningWaitHandle.cs

   1 //------------------------------------------------------------------------------
   2 // <copyright file="StopListeningWaitHandle.cs" company="Microsoft">
   3 //     Copyright (c) Microsoft Corporation.  All rights reserved.
   4 // </copyright>
   5 //------------------------------------------------------------------------------
   6
   7 namespace System.Web.Util {
   8     using Microsoft.Win32.SafeHandles;
   9     using System;
  10     using System.Diagnostics.CodeAnalysis;
  11     using System.Runtime.ConstrainedExecution;
  12     using System.Runtime.InteropServices;
  13     using System.Security;
  14     using System.Threading;
  15     using System.Web.Hosting;
  16
  17     // This is a ManualResetEvent that corresponds to the OnGlobalStopListening event.
  18     internal sealed class StopListeningWaitHandle : WaitHandle {
  19         [SuppressMessage("Microsoft.Reliability", "CA2006:UseSafeHandleToEncapsulateNativeResources", Justification = @"This is a pseudohandle so shouldn't be closed.")]
  20         private static IntPtr _processHandle = GetCurrentProcess();
  21
  22         public StopListeningWaitHandle() {
  23             // This handle is process-wide and not ref counted, so no need to wrap inside a SafeHandle
  24             IntPtr eventHandle = UnsafeIISMethods.MgdGetStopListeningEventHandle();
  25
  26             // Per documentation for RegisterWaitForSingleObject, we need to duplicate handles
  27             // before asynchronously waiting on them.
  28             SafeWaitHandle safeWaitHandle;
  29             bool succeeded = DuplicateHandle(
  30                 hSourceProcessHandle: _processHandle,
  31                 hSourceHandle: eventHandle,
  32                 hTargetProcessHandle: _processHandle,
  33                 lpTargetHandle: out safeWaitHandle,
  34                 dwDesiredAccess: 0,
  35                 bInheritHandle: false,
  36                 dwOptions: 2 /* DUPLICATE_SAME_ACCESS */);
  37
  38             if (!succeeded) {
  39                 int hr = Marshal.GetHRForLastWin32Error();
  40                 Marshal.ThrowExceptionForHR(hr);
  41             }
  42
  43             this.SafeWaitHandle = safeWaitHandle;
  44         }
  45
  46         [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
  47         [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
  48         [SuppressUnmanagedCodeSecurity]
  49         [SuppressMessage("Microsoft.Security", "CA2118:ReviewSuppressUnmanagedCodeSecurityUsage", Justification = "We carefully control this method's callers.")]
  50         private static extern IntPtr GetCurrentProcess();
  51
  52         [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
  53         [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
  54         [SuppressUnmanagedCodeSecurity]
  55         [SuppressMessage("Microsoft.Security", "CA2118:ReviewSuppressUnmanagedCodeSecurityUsage", Justification = "We carefully control this method's callers.")]
  56         private static extern bool DuplicateHandle([In] IntPtr hSourceProcessHandle, [In] IntPtr hSourceHandle, [In] IntPtr hTargetProcessHandle, [Out] out SafeWaitHandle lpTargetHandle, [In] uint dwDesiredAccess, [In] bool bInheritHandle, [In] uint dwOptions);
  57     }
  58 }