Cer Enum
Definition
Important
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Caution
The Constrained Execution Region (CER) feature is not supported.
Specifies a method's behavior when called within a constrained execution region.
public enum class Cer
[System.Obsolete("The Constrained Execution Region (CER) feature is not supported.", DiagnosticId="SYSLIB0004", UrlFormat="https://aka.ms/dotnet-warnings/{0}")]
public enum Cer
public enum Cer
[System.Serializable]
public enum Cer
[<System.Obsolete("The Constrained Execution Region (CER) feature is not supported.", DiagnosticId="SYSLIB0004", UrlFormat="https://aka.ms/dotnet-warnings/{0}")>]
type Cer =
type Cer =
[<System.Serializable>]
type Cer =
Public Enum Cer
- Inheritance
- Attributes
Fields
Name | Value | Description |
---|---|---|
None | 0 | The method, type, or assembly has no concept of a CER. It does not take advantage of CER guarantees. |
MayFail | 1 | In the face of exceptional conditions, the method might fail. In this case, the method will report back to the calling method whether it succeeded or failed. The method must have a CER around the method body to ensure that it can report the return value. |
Success | 2 | In the face of exceptional conditions, the method is guaranteed to succeed. You should always construct a CER around the method that is called, even when it is called from within a non-CER region. A method is successful if it accomplishes what is intended. For example, marking Count with |
Examples
The following code example demonstrates the use of the Cer enumeration when specifying a constrained execution region for a method. This code example is part of a larger example provided for the ReliabilityContractAttribute constructor.
[ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
[MethodImpl(MethodImplOptions.NoInlining)]
void StackDepth2()
{
try
{
consistentLevel2 = false;
if (depth == 2)
Thread.Sleep(-1);
StackDepth3();
}
finally
{
consistentLevel2 = true;
}
}
<ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)>
<MethodImpl(MethodImplOptions.NoInlining)>
Sub StackDepth2()
Try
consistentLevel2 = False
If depth = 2 Then Thread.Sleep(-1)
StackDepth3()
Finally
consistentLevel2 = True
End Try
End Sub
Remarks
The Cer enumeration specifies the behavior of a method, type, or assembly within a constrained execution region (CER). Use one of the three available values to indicate that the entity will succeed, has no knowledge of a CER, or might (deterministically) be able to report success or failure.
A CER provides guarantees that the region of code will execute uninterrupted even if an asynchronous exception such as an aborted thread out-of-memory exception, or stack overflow is raised.
However, the Cer.None
enumeration value indicates that the method, type, or assembly has no concept of a CER. It does not take advantage of CER guarantees. This implies the following:
In the face of exceptional conditions the method might fail.
The method might or might not report that it failed (it is non-deterministic).
The method is not written with CERs in mind (which is the most likely scenario).
If a method, type, or assembly is not explicitly marked to succeed, it is implicitly marked as Cer.None
.