Monitor.TryEnter Method (Object)
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Attempts to acquire an exclusive lock on the specified object.
Namespace: System.Threading
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
Public Shared Function TryEnter ( _
obj As Object _
) As Boolean
public static bool TryEnter(
Object obj
)
Parameters
- obj
Type: System.Object
The object on which to acquire the lock.
Return Value
Type: System.Boolean
true if the current thread acquires the lock; otherwise, false.
Exceptions
| Exception | Condition |
|---|---|
| ArgumentNullException | The obj parameter is nulla null reference (Nothing in Visual Basic). |
Remarks
If successful, this method acquires an exclusive lock on the obj parameter. This method returns immediately, whether or not the lock is available.
This method is similar to Enter, but it will never block. If the thread cannot enter without blocking, the method returns false, and the thread does not enter the critical section.
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Note:Examples
The following example demonstrates how to use the TryEnter method. This code is part of a larger example provided for the Enter method.
' Try to add an element to the queue: Add the element to the queue
' only if the lock is immediately available.
Public Function TryEnqueue(ByVal qValue As T) As Boolean
' Request the lock.
If Monitor.TryEnter(m_inputQueue) Then
Try
m_inputQueue.Enqueue(qValue)
Finally
' Ensure that the lock is released.
Monitor.Exit(m_inputQueue)
End Try
Return True
Else
Return False
End If
End Function
// Try to add an element to the queue: Add the element to the queue
// only if the lock is immediately available.
public bool TryEnqueue(T qValue)
{
// Request the lock.
if (Monitor.TryEnter(m_inputQueue))
{
try
{
m_inputQueue.Enqueue(qValue);
}
finally
{
// Ensure that the lock is released.
Monitor.Exit(m_inputQueue);
}
return true;
}
else
{
return false;
}
}
Version Information
Silverlight
Supported in: 5, 4, 3
Silverlight for Windows Phone
Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0
XNA Framework
Supported in: Xbox 360, Windows Phone OS 7.0
Platforms
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.
See Also