WorkItem.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / xsp / System / Web / Util / WorkItem.cs / 1305376 / WorkItem.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

namespace System.Web.Util { 
 
    using System.Runtime.InteropServices;
    using System.Security.Permissions; 
    using System.Threading;

//
// Support for positing of work items to a different thread 
//
 
 
/// 
///    [To be supplied.] 
/// 
public delegate void WorkItemCallback();

 
/// 
///    [To be supplied.] 
///  
public class WorkItem {
 
    private static bool _useQueueUserWorkItem = true;
    private static WaitCallback _onQueueUserWorkItemCompletion = new WaitCallback(OnQueueUserWorkItemCompletion);

 
    /// 
    ///    [To be supplied.] 
    ///  

    [SecurityPermission(SecurityAction.Demand, Unrestricted=true)] 
    public static void Post(WorkItemCallback callback) {
#if !FEATURE_PAL // ROTORTODO
        if (Environment.OSVersion.Platform != PlatformID.Win32NT)
            throw new PlatformNotSupportedException(SR.GetString(SR.RequiresNT)); 
#else // !FEATURE_PAL
        throw new NotImplementedException("ROTORTODO"); 
#endif // !FEATURE_PAL 
        PostInternal(callback);
    } 

    // assert to disregard the user code up the compressed stack
    [PermissionSet(SecurityAction.Assert, Unrestricted=true)]
    private static void CallCallbackWithAssert(WorkItemCallback callback) { 
        callback();
    } 
 
    private static void OnQueueUserWorkItemCompletion(Object state) {
        WorkItemCallback callback = state as WorkItemCallback; 

        if (callback != null) {
            CallCallbackWithAssert(callback);
        } 
    }
 
    internal static void PostInternal(WorkItemCallback callback) { 
        if (_useQueueUserWorkItem) {
            ThreadPool.QueueUserWorkItem(_onQueueUserWorkItemCompletion, callback); 
        }
        else {
            WrappedWorkItemCallback w = new WrappedWorkItemCallback(callback);
            w.Post(); 
        }
    } 
} 

internal class WrappedWorkItemCallback { 
    private GCHandle         _rootedThis;
    private WorkItemCallback _originalCallback;
    private WorkItemCallback _wrapperCallback;
 
    internal WrappedWorkItemCallback(WorkItemCallback callback) {
        _originalCallback = callback; 
        _wrapperCallback = new WorkItemCallback(this.OnCallback); 
    }
 
    internal void Post() {
        _rootedThis = GCHandle.Alloc(this);

        if (UnsafeNativeMethods.PostThreadPoolWorkItem(_wrapperCallback) != 1) { 
            _rootedThis.Free();
            throw new HttpException(SR.GetString(SR.Cannot_post_workitem)); 
        } 
    }
 
    private void OnCallback() {
        _rootedThis.Free();
        _originalCallback();
    } 
}
 
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
//------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

namespace System.Web.Util { 
 
    using System.Runtime.InteropServices;
    using System.Security.Permissions; 
    using System.Threading;

//
// Support for positing of work items to a different thread 
//
 
 
/// 
///    [To be supplied.] 
/// 
public delegate void WorkItemCallback();

 
/// 
///    [To be supplied.] 
///  
public class WorkItem {
 
    private static bool _useQueueUserWorkItem = true;
    private static WaitCallback _onQueueUserWorkItemCompletion = new WaitCallback(OnQueueUserWorkItemCompletion);

 
    /// 
    ///    [To be supplied.] 
    ///  

    [SecurityPermission(SecurityAction.Demand, Unrestricted=true)] 
    public static void Post(WorkItemCallback callback) {
#if !FEATURE_PAL // ROTORTODO
        if (Environment.OSVersion.Platform != PlatformID.Win32NT)
            throw new PlatformNotSupportedException(SR.GetString(SR.RequiresNT)); 
#else // !FEATURE_PAL
        throw new NotImplementedException("ROTORTODO"); 
#endif // !FEATURE_PAL 
        PostInternal(callback);
    } 

    // assert to disregard the user code up the compressed stack
    [PermissionSet(SecurityAction.Assert, Unrestricted=true)]
    private static void CallCallbackWithAssert(WorkItemCallback callback) { 
        callback();
    } 
 
    private static void OnQueueUserWorkItemCompletion(Object state) {
        WorkItemCallback callback = state as WorkItemCallback; 

        if (callback != null) {
            CallCallbackWithAssert(callback);
        } 
    }
 
    internal static void PostInternal(WorkItemCallback callback) { 
        if (_useQueueUserWorkItem) {
            ThreadPool.QueueUserWorkItem(_onQueueUserWorkItemCompletion, callback); 
        }
        else {
            WrappedWorkItemCallback w = new WrappedWorkItemCallback(callback);
            w.Post(); 
        }
    } 
} 

internal class WrappedWorkItemCallback { 
    private GCHandle         _rootedThis;
    private WorkItemCallback _originalCallback;
    private WorkItemCallback _wrapperCallback;
 
    internal WrappedWorkItemCallback(WorkItemCallback callback) {
        _originalCallback = callback; 
        _wrapperCallback = new WorkItemCallback(this.OnCallback); 
    }
 
    internal void Post() {
        _rootedThis = GCHandle.Alloc(this);

        if (UnsafeNativeMethods.PostThreadPoolWorkItem(_wrapperCallback) != 1) { 
            _rootedThis.Free();
            throw new HttpException(SR.GetString(SR.Cannot_post_workitem)); 
        } 
    }
 
    private void OnCallback() {
        _rootedThis.Free();
        _originalCallback();
    } 
}
 
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.

Link Menu

Network programming in C#, Network Programming in VB.NET, Network Programming in .NET
This book is available now!
Buy at Amazon US or
Buy at Amazon UK