.NET Framework Class Library
CountdownEvent Class

[This documentation is for preview only, and is subject to change in later releases. Blank topics are included as placeholders.]

Represents a synchronization primitive that is signaled when its count reaches zero.

Namespace:  System.Threading
Assembly:  mscorlib (in mscorlib.dll)
Syntax
Visual Basic (Declaration) 
<ComVisibleAttribute(False)> _
<HostProtectionAttribute(SecurityAction.LinkDemand, Synchronization := True,  _
    ExternalThreading := True)> _
Public Class CountdownEvent _
    Implements IDisposable
Visual Basic (Usage) 
Dim instance As CountdownEvent
C# 
[ComVisibleAttribute(false)]
[HostProtectionAttribute(SecurityAction.LinkDemand, Synchronization = true, 
    ExternalThreading = true)]
public class CountdownEvent : IDisposable
Visual C++ 
[ComVisibleAttribute(false)]
[HostProtectionAttribute(SecurityAction::LinkDemand, Synchronization = true, 
    ExternalThreading = true)]
public ref class CountdownEvent : IDisposable
F# 
[<ComVisibleAttribute(false)>]
[<HostProtectionAttribute(SecurityAction.LinkDemand, Synchronization = true, 
    ExternalThreading = true)>]
type CountdownEvent =  
    class
        interface IDisposable
    end
Remarks
NoteNote

The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: Synchronization | ExternalThreading. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.
Inheritance Hierarchy
System..::.Object
  System.Threading..::.CountdownEvent
Thread Safety

All public and protected members of CountdownEvent are thread-safe and may be used concurrently from multiple threads, with the exception of Dispose, which must only be used when all other operations on the CountdownEvent have completed, and Reset, which should only be used when no other threads are accessing the event.
Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Version Information

.NET Framework

Supported in: 4

.NET Framework Client Profile

Supported in: 4
See Also

Reference

CountdownEvent Members
System.Threading Namespace

Other Resources

CountdownEvent
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