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Thread.Join Method (TimeSpan)

Blocks the calling thread until a thread terminates or the specified time elapses, while continuing to perform standard COM and SendMessage pumping.

Namespace:  System.Threading
Assembly:  mscorlib (in mscorlib.dll)

[HostProtectionAttribute(SecurityAction.LinkDemand, Synchronization = true, 
	ExternalThreading = true)]
public bool Join(
	TimeSpan timeout


Type: System.TimeSpan
A TimeSpan set to the amount of time to wait for the thread to terminate.

Return Value

Type: System.Boolean
true if the thread terminated; false if the thread has not terminated after the amount of time specified by the timeout parameter has elapsed.


The value of timeout is negative and is not equal to Timeout.Infinite in milliseconds, or is greater than Int32.MaxValue milliseconds.


The caller attempted to join a thread that is in the Unstarted state.

If Timeout.Infinite is specified for timeout, this method behaves identically to the Join() method overload, except for the return value.

If the thread has already terminated when Join is called, the method returns immediately.

This method changes the state of the current thread to include WaitSleepJoin. You cannot invoke Join on a thread that is in the ThreadState.Unstarted state.


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.

The following code example demonstrates how to use a TimeSpan value with the Join method.

using System;
using System.Threading;

class Test
    static TimeSpan waitTime = new TimeSpan(0, 0, 1);

    public static void Main() 
        Thread newThread = 
            new Thread(new ThreadStart(Work));

        if(newThread.Join(waitTime + waitTime))
            Console.WriteLine("New thread terminated.");
            Console.WriteLine("Join timed out.");

    static void Work()

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.