SemaphoreRights Enum

Definition

Namespace:

System.Security.AccessControl

Assembly:

System.Threading.AccessControl.dll

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

This enumeration supports a bitwise combination of its member values.

public enum class SemaphoreRights

[System.Flags]
public enum SemaphoreRights

[<System.Flags>]
type SemaphoreRights = 

Public Enum SemaphoreRights

Inheritance

Object

ValueType

Enum

SemaphoreRights

Attributes

FlagsAttribute

Fields

Name	Value	Description
Modify	2	The right to release a named semaphore.
Delete	65536	The right to delete a named semaphore.
ReadPermissions	131072	The right to open and copy the access rules and audit rules for a named semaphore.
ChangePermissions	262144	The right to change the security and audit rules associated with a named semaphore.
TakeOwnership	524288	The right to change the owner of a named semaphore.
Synchronize	1048576	The right to wait on a named semaphore.
FullControl	2031619	The right to exert full control over a named semaphore, and to modify its access rules and audit rules.

Examples

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.

Note

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 + "\\" + 
            Environment.UserName;

        // 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, 
            AccessControlType.Allow);
        mSec.AddAccessRule(rule);

        // Add a rule that denies the current user the 
        // right to change permissions on the semaphore.
        rule = new SemaphoreAccessRule(user, 
            SemaphoreRights.ChangePermissions, 
            AccessControlType.Deny);
        mSec.AddAccessRule(rule);

        // Display the rules in the security object.
        ShowSecurity(mSec);

        // 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, 
            SemaphoreRights.ReadPermissions, 
            AccessControlType.Allow);
        mSec.AddAccessRule(rule);

        ShowSecurity(mSec);
    }

    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);
            Console.WriteLine();
        }
    }
}

/*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
 */

Imports System.Threading
Imports System.Security.AccessControl
Imports System.Security.Principal

Public Class Example

    Public Shared Sub Main()

        ' Create a string representing the current user.
        Dim user As String = Environment.UserDomainName _ 
            & "\" & Environment.UserName

        ' Create a security object that grants no access.
        Dim mSec As New SemaphoreSecurity()

        ' Add a rule that grants the current user the 
        ' right to enter or release the semaphore.
        Dim rule As New SemaphoreAccessRule(user, _
            SemaphoreRights.Synchronize _
            Or SemaphoreRights.Modify, _
            AccessControlType.Allow)
        mSec.AddAccessRule(rule)

        ' Add a rule that denies the current user the 
        ' right to change permissions on the semaphore.
        rule = New SemaphoreAccessRule(user, _
            SemaphoreRights.ChangePermissions, _
            AccessControlType.Deny)
        mSec.AddAccessRule(rule)

        ' Display the rules in the security object.
        ShowSecurity(mSec)

        ' 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, _
            SemaphoreRights.ReadPermissions, _
            AccessControlType.Allow)
        mSec.AddAccessRule(rule)

        ShowSecurity(mSec)

    End Sub 

    Private Shared Sub ShowSecurity(ByVal security As SemaphoreSecurity)
        Console.WriteLine(vbCrLf & "Current access rules:" & vbCrLf)

        For Each ar As SemaphoreAccessRule In _
            security.GetAccessRules(True, True, GetType(NTAccount))

            Console.WriteLine("        User: {0}", ar.IdentityReference)
            Console.WriteLine("        Type: {0}", ar.AccessControlType)
            Console.WriteLine("      Rights: {0}", ar.SemaphoreRights)
            Console.WriteLine()
        Next

    End Sub
End Class 

'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

Remarks

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 Semaphore.Semaphore(Int32, Int32, String, Boolean, SemaphoreSecurity) constructor and the Semaphore.SetAccessControl method.

For the numeric values of the underlying Windows access rights, see Synchronization Object Security and Access Rights (Windows).

See also

• SemaphoreAccessRule
• SemaphoreSecurity