LockRecursionException Class
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The exception that is thrown when recursive entry into a lock is not compatible with the recursion policy for the lock.
public ref class LockRecursionException : Exception
public class LockRecursionException : Exception
[System.Serializable]
public class LockRecursionException : Exception
type LockRecursionException = class
inherit Exception
[<System.Serializable>]
type LockRecursionException = class
inherit Exception
Public Class LockRecursionException
Inherits Exception
- Inheritance
- Attributes
The following example shows two causes of LockRecursionException when using the ReaderWriterLockSlim class. The program creates a ReaderWriterLockSlim by using the parameterless constructor, which disallows recursion. The program then starts a thread that enters the lock in read mode. The thread tries to enter the lock recursively in read mode, and catches the resulting exception. Finally, the thread tries to enter write mode, which would create a potential for deadlocks. The thread catches the resulting exception.
using System;
using System.Threading;
class Example
{
// By default, the lock recursion policy for a new
// ReaderWriterLockSlim does not allow recursion.
static ReaderWriterLockSlim rwls = new ReaderWriterLockSlim();
static void ThreadProc()
{
Console.WriteLine("Acquire the reader lock.");
rwls.EnterReadLock();
try
{
Console.WriteLine("\nAttempt to acquire the reader lock recursively:");
rwls.EnterReadLock();
}
catch (LockRecursionException lre)
{
Console.WriteLine("{0}: {1}",
lre.GetType().Name, lre.Message);
}
try
{
Console.WriteLine("\nAttempt to acquire the writer lock recursively:");
rwls.EnterWriteLock();
}
catch (LockRecursionException lre)
{
Console.WriteLine("{0}: {1}",
lre.GetType().Name, lre.Message);
}
}
static void Main()
{
Thread t = new Thread(ThreadProc);
t.Start();
t.Join();
}
}
/* This code example produces output similar to the following:
Acquire the reader lock.
Attempt to acquire the reader lock recursively:
LockRecursionException: Recursive read lock acquisitions not allowed in this mode.
Attempt to acquire the writer lock recursively:
LockRecursionException: Write lock may not be acquired with read lock held. This pattern is prone to deadlocks. Consider using the upgrade lock.
*/
Imports System.Threading
Class Example
' By default, the lock recursion policy for a new
' ReaderWriterLockSlim does not allow recursion.
Private Shared rwls As New ReaderWriterLockSlim()
Shared Sub ThreadProc()
Console.WriteLine("Acquire the reader lock.")
rwls.EnterReadLock()
Try
Console.WriteLine(vbCrLf & _
"Attempt to acquire the reader lock recursively:")
rwls.EnterReadLock()
Catch lre As LockRecursionException
Console.WriteLine("{0}: {1}", _
lre.GetType().Name, lre.Message)
End Try
Try
Console.WriteLine(vbCrLf & _
"Attempt to acquire the writer lock recursively:")
rwls.EnterWriteLock()
Catch lre As LockRecursionException
Console.WriteLine("{0}: {1}", _
lre.GetType().Name, lre.Message)
End Try
End Sub
Shared Sub Main()
Dim t As New Thread(AddressOf ThreadProc)
t.Start()
t.Join()
End Sub
End Class
' This code example produces output similar to the following:
'
'Acquire the reader lock.
'
'Attempt to acquire the reader lock recursively:
'LockRecursionException: Recursive read lock acquisitions not allowed in this mode.
'
'Attempt to acquire the writer lock recursively:
'LockRecursionException: Write lock may not be acquired with read lock held. This pattern is prone to deadlocks. Consider using the upgrade lock.
'
LockRecursionException is thrown for several reasons, including the following:
If a thread tries to enter an instance of ReaderWriterLockSlim recursively, but the instance does not support recursion.
If a thread tries to enter a ReaderWriterLockSlim instance in write mode or upgradeable mode when the thread initially entered the lock in read mode. This represents a potential deadlock and therefore is not allowed.
If allowing one more level of recursion would exceed the maximum value for the internal storage counter used to track recursions. This limit is so large that applications should never encounter it.
Lock |
Initializes a new instance of the LockRecursionException class with a system-supplied message that describes the error. |
Lock |
Obsolete.
Initializes a new instance of the LockRecursionException class with serialized data. |
Lock |
Initializes a new instance of the LockRecursionException class with a specified error message and a reference to the inner exception that is the cause of this exception. |
Lock |
Initializes a new instance of the LockRecursionException class with a specified message that describes the error. |
Data |
Gets a collection of key/value pairs that provide additional user-defined information about the exception. (Inherited from Exception) |
Help |
Gets or sets a link to the help file associated with this exception. (Inherited from Exception) |
HResult |
Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception. (Inherited from Exception) |
Inner |
Gets the Exception instance that caused the current exception. (Inherited from Exception) |
Message |
Gets a message that describes the current exception. (Inherited from Exception) |
Source |
Gets or sets the name of the application or the object that causes the error. (Inherited from Exception) |
Stack |
Gets a string representation of the immediate frames on the call stack. (Inherited from Exception) |
Target |
Gets the method that throws the current exception. (Inherited from Exception) |
Equals(Object) |
Determines whether the specified object is equal to the current object. (Inherited from Object) |
Get |
When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions. (Inherited from Exception) |
Get |
Serves as the default hash function. (Inherited from Object) |
Get |
Obsolete.
When overridden in a derived class, sets the SerializationInfo with information about the exception. (Inherited from Exception) |
Get |
Gets the runtime type of the current instance. (Inherited from Exception) |
Memberwise |
Creates a shallow copy of the current Object. (Inherited from Object) |
To |
Creates and returns a string representation of the current exception. (Inherited from Exception) |
Serialize |
Obsolete.
Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception. (Inherited from Exception) |
Product | Versions |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.6, 2.0, 2.1 |
UWP | 10.0 |
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