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SemaphoreRights Enumeration

Note: This enumeration is new in the .NET Framework version 2.0.

Specifies the access control rights that can be applied to named system semaphore objects.

This enumeration has a FlagsAttribute attribute that allows a bitwise combination of its member values.

Namespace: System.Security.AccessControl
Assembly: System (in system.dll)

public enum SemaphoreRights
/** @attribute ComVisibleAttribute(false) */ 
/** @attribute FlagsAttribute() */ 
public enum SemaphoreRights
public enum SemaphoreRights

 Member nameDescription
ChangePermissionsThe right to change the security and audit rules associated with a named semaphore. 
DeleteThe right to delete a named semaphore. 
FullControlThe right to exert full control over a named semaphore, and to modify its access rules and audit rules. 
ModifyThe right to release a named semaphore. 
ReadPermissionsThe right to open and copy the access rules and audit rules for a named semaphore. 
SynchronizeThe right to wait on a named semaphore. 
TakeOwnershipThe right to change the owner of a named semaphore. 

Use the SemaphoreRights enumeration to specify access control rights when you create SemaphoreSecurity objects. To apply access rights to a named system semaphore, use SemaphoreSecurity objects with the System.Threading.Semaphore constructor and the Semaphore.SetAccessControl method.

The following code example demonstrates the use of SemaphoreRights values when creating and using SemaphoreAccessRule objects. The example creates a SemaphoreSecurity object, adds rules that allow and deny various rights for the current user, and displays the resulting pair of rules. The example then allows new rights for the current user and displays the result, showing that the new rights are merged with the existing AccessControlType.Allow rule.


This example does not attach the security object to an Semaphore object; see SemaphoreSecurity, Semaphore.GetAccessControl method, and Semaphore.SetAccessControl.

using System;
using System.Threading;
using System.Security.AccessControl;
using System.Security.Principal;

public class Example
    public static void Main()
        // Create a string representing the current user.
        string user = Environment.UserDomainName + "\\" + 

        // Create a security object that grants no access.
        SemaphoreSecurity mSec = new SemaphoreSecurity();

        // Add a rule that grants the current user the 
        // right to enter or release the semaphore.
        SemaphoreAccessRule rule = new SemaphoreAccessRule(user, 
            SemaphoreRights.Synchronize | SemaphoreRights.Modify, 

        // Add a rule that denies the current user the 
        // right to change permissions on the semaphore.
        rule = new SemaphoreAccessRule(user, 

        // Display the rules in the security object.

        // Add a rule that allows the current user the 
        // right to read permissions on the semaphore. This rule
        // is merged with the existing Allow rule.
        rule = new SemaphoreAccessRule(user, 


    private static void ShowSecurity(SemaphoreSecurity security)
        Console.WriteLine("\r\nCurrent access rules:\r\n");

        foreach(SemaphoreAccessRule ar in 
            security.GetAccessRules(true, true, typeof(NTAccount)))
            Console.WriteLine("        User: {0}", ar.IdentityReference);
            Console.WriteLine("        Type: {0}", ar.AccessControlType);
            Console.WriteLine("      Rights: {0}", ar.SemaphoreRights);

/*This code example produces output similar to following:

Current access rules:

        User: TestDomain\TestUser
        Type: Deny
      Rights: ChangePermissions

        User: TestDomain\TestUser
        Type: Allow
      Rights: Modify, Synchronize

Current access rules:

        User: TestDomain\TestUser
        Type: Deny
      Rights: ChangePermissions

        User: TestDomain\TestUser
        Type: Allow
      Rights: Modify, ReadPermissions, Synchronize

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

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

.NET Framework

Supported in: 2.0

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