MutexAccessRule Constructors

Definition

Namespace:

System.Security.AccessControl

Assembly:

System.Threading.AccessControl.dll

Initializes a new instance of the MutexAccessRule class.

Overloads

MutexAccessRule(IdentityReference, MutexRights, AccessControlType)	Initializes a new instance of the MutexAccessRule class, specifying the user or group the rule applies to, the access rights, and whether the specified access rights are allowed or denied.
MutexAccessRule(String, MutexRights, AccessControlType)	Initializes a new instance of the MutexAccessRule class, specifying the name of the user or group the rule applies to, the access rights, and whether the specified access rights are allowed or denied.

MutexAccessRule(IdentityReference, MutexRights, AccessControlType)

Initializes a new instance of the MutexAccessRule class, specifying the user or group the rule applies to, the access rights, and whether the specified access rights are allowed or denied.

public:
 MutexAccessRule(System::Security::Principal::IdentityReference ^ identity, System::Security::AccessControl::MutexRights eventRights, System::Security::AccessControl::AccessControlType type);

public MutexAccessRule (System.Security.Principal.IdentityReference identity, System.Security.AccessControl.MutexRights eventRights, System.Security.AccessControl.AccessControlType type);

new System.Security.AccessControl.MutexAccessRule : System.Security.Principal.IdentityReference * System.Security.AccessControl.MutexRights * System.Security.AccessControl.AccessControlType -> System.Security.AccessControl.MutexAccessRule

Public Sub New (identity As IdentityReference, eventRights As MutexRights, type As AccessControlType)

Parameters

identity

IdentityReference

The user or group the rule applies to. Must be of type SecurityIdentifier or a type such as NTAccount that can be converted to type SecurityIdentifier.

eventRights

MutexRights

A bitwise combination of MutexRights values specifying the rights allowed or denied.

type

AccessControlType

One of the AccessControlType values specifying whether the rights are allowed or denied.

Exceptions

ArgumentOutOfRangeException

eventRights specifies an invalid value.

-or-

type specifies an invalid value.

ArgumentNullException

identity is null.

-or-

eventRights is zero.

ArgumentException

identity is neither of type SecurityIdentifier nor of a type such as NTAccount that can be converted to type SecurityIdentifier.

Remarks

To wait on a Mutex (by calling the WaitOne, WaitAny or WaitAll method), a user must have MutexRights.Synchronize access. To release the mutex, by calling the ReleaseMutex method, the user must have MutexRights.Modify access.

MutexAccessRule(String, MutexRights, AccessControlType)

Initializes a new instance of the MutexAccessRule class, specifying the name of the user or group the rule applies to, the access rights, and whether the specified access rights are allowed or denied.

public:
 MutexAccessRule(System::String ^ identity, System::Security::AccessControl::MutexRights eventRights, System::Security::AccessControl::AccessControlType type);

public MutexAccessRule (string identity, System.Security.AccessControl.MutexRights eventRights, System.Security.AccessControl.AccessControlType type);

new System.Security.AccessControl.MutexAccessRule : string * System.Security.AccessControl.MutexRights * System.Security.AccessControl.AccessControlType -> System.Security.AccessControl.MutexAccessRule

Public Sub New (identity As String, eventRights As MutexRights, type As AccessControlType)

Parameters

identity

String

The name of the user or group the rule applies to.

eventRights

MutexRights

A bitwise combination of MutexRights values specifying the rights allowed or denied.

type

AccessControlType

One of the AccessControlType values specifying whether the rights are allowed or denied.

Exceptions

ArgumentOutOfRangeException

eventRights specifies an invalid value.

-or-

type specifies an invalid value.

ArgumentNullException

eventRights is zero.

ArgumentException

identity is null.

-or-

identity is a zero-length string.

-or-

identity is longer than 512 characters.

Examples

The following code example demonstrates the use of this constructor to create MutexAccessRule objects. The example creates a MutexSecurity 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 Allow rule.

Note

This example does not attach the security object to a Mutex object. Examples that attach security objects can be found in Mutex.GetAccessControl and Mutex.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.
        MutexSecurity mSec = new MutexSecurity();

        // Add a rule that grants the current user the 
        // right to enter or release the mutex.
        MutexAccessRule rule = new MutexAccessRule(user, 
            MutexRights.Synchronize | MutexRights.Modify, 
            AccessControlType.Allow);
        mSec.AddAccessRule(rule);

        // Add a rule that denies the current user the 
        // right to change permissions on the mutex.
        rule = new MutexAccessRule(user, 
            MutexRights.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 mutex. This rule
        // is merged with the existing Allow rule.
        rule = new MutexAccessRule(user, 
            MutexRights.ReadPermissions, 
            AccessControlType.Allow);
        mSec.AddAccessRule(rule);

        ShowSecurity(mSec);
    }

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

        foreach(MutexAccessRule 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.MutexRights);
            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 MutexSecurity()

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

        ' Add a rule that denies the current user the 
        ' right to change permissions on the mutex.
        rule = New MutexAccessRule(user, _
            MutexRights.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 mutex. This rule
        ' is merged with the existing Allow rule.
        rule = New MutexAccessRule(user, _
            MutexRights.ReadPermissions, _
            AccessControlType.Allow)
        mSec.AddAccessRule(rule)

        ShowSecurity(mSec)

    End Sub 

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

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

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

To wait on a Mutex (by calling the WaitOne, WaitAny or WaitAll method), a user must have MutexRights.Synchronize access. To release the mutex, by calling the ReleaseMutex methods, the user must have MutexRights.Modify access.

This constructor is equivalent to creating an NTAccount object, by passing identity to the NTAccount.NTAccount(String) constructor, and passing the newly created NTAccount object to the MutexAccessRule(IdentityReference, MutexRights, AccessControlType) constructor.