ContextProperty.cs source code in C# .NET

                        Code:
                         / FXUpdate3074 / FXUpdate3074 / 1.1 / untmp / whidbey / QFE / ndp / clr / src / BCL / System / Runtime / Remoting / ContextProperty.cs / 2 / ContextProperty.cs
                        
                        
                            // ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 
/*============================================================
** 
** File:    ContextProperty.cs 
**
** A contextProperty is a name-value pair holding the property 
** name and the object representing the property in a context.
** An array of these is returned by Context::GetContextProperties()
**
** 
**
===========================================================*/ 
 
namespace System.Runtime.Remoting.Contexts {
 
    using System;
    using System.Threading;
    using System.Reflection;
    using System.Runtime.InteropServices; 
    using System.Runtime.CompilerServices;
    using System.Runtime.Remoting.Activation; 
    using System.Security.Permissions; 

    ///  
    [SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.Infrastructure)]
    [SecurityPermissionAttribute(SecurityAction.InheritanceDemand, Flags=SecurityPermissionFlag.Infrastructure)]
[System.Runtime.InteropServices.ComVisible(true)]
    public class ContextProperty { 
        internal String _name;           // property name
        internal Object _property;       // property object 
 
    /// 
        public virtual String Name { 
            get {
                return _name;
            }
        } 

    ///  
        public virtual Object Property { 
            get {
                return _property; 
            }
        }

        /* can't create outside the package */ 
        internal ContextProperty(String name, Object prop)
        { 
            _name = name; 
            _property = prop;
        } 
    }

    //  The IContextAttribute interface is implemented by attribute classes.
    //  The attributes contribute a property which resides in a context and 
    //  enforces a specific policy for the objects created in that context.
    ///  
[System.Runtime.InteropServices.ComVisible(true)] 
    public interface IContextAttribute
    { 
    /// 
        [SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.Infrastructure)]
        bool IsContextOK(Context ctx, IConstructionCallMessage msg);
    ///  
        [SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.Infrastructure)]
        void GetPropertiesForNewContext(IConstructionCallMessage msg); 
    } 

   //   This interface is exposed by the property contributed to a context 
   //   by an attribute. By default, it is also implemented by the ContextAttribute
   //   base class which every attribute class must extend from.
    /// 
[System.Runtime.InteropServices.ComVisible(true)] 
    public interface IContextProperty
    { 
    ///  
       //   This is the name under which the property will be added
       //   to the {name,property} table in a context. 
        String Name
        {
        [SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.Infrastructure)]
        get; 
    }
    ///  
       //   After forming the newCtx, we ask each property if it is happy 
       //   with the context. We expect most implementations to say yes.
        [SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.Infrastructure)] 
        bool IsNewContextOK(Context newCtx);
    /// 

        // New method. All properties are notified when the context 
        // they are in is frozen.
        [SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.Infrastructure)] 
        void Freeze(Context newContext); 
    }
 
    /// 
[System.Runtime.InteropServices.ComVisible(true)]
    public interface IContextPropertyActivator
    { 
    /// 
        // This method lets properties in the current context have a say in 
        // whether an activation may be done 'here' or not. 
        [SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.Infrastructure)]
        bool IsOKToActivate(IConstructionCallMessage msg); 
    /// 
        [SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.Infrastructure)]
        void CollectFromClientContext(IConstructionCallMessage msg);
    ///  
        [SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.Infrastructure)]
        bool DeliverClientContextToServerContext(IConstructionCallMessage msg); 
    ///  
        [SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.Infrastructure)]
        void CollectFromServerContext(IConstructionReturnMessage msg); 
    /// 
        [SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.Infrastructure)]
        bool DeliverServerContextToClientContext(IConstructionReturnMessage msg);
    } 

 
   //   All context attribute classes must extend from this base class. 
   //   This class provides the base implementations which the derived
   //   classes are free to over-ride. The base implementations provide 
   //   the default answers to various questions.

    /// 
    [AttributeUsage(AttributeTargets.Class), Serializable] 
    [SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.Infrastructure)]
    [SecurityPermissionAttribute(SecurityAction.InheritanceDemand, Flags=SecurityPermissionFlag.Infrastructure)] 
[System.Runtime.InteropServices.ComVisible(true)] 
    public class ContextAttribute
        : Attribute, IContextAttribute, IContextProperty 
    {
    /// 
        protected String AttributeName;
 
        // The derived class must call: base(name);
    ///  
        public ContextAttribute(String name) 
        {
            AttributeName = name; 
        }

        // IContextPropery::Name
        // Default implementation provides AttributeName as the property name. 
    /// 
        public virtual String Name { get {return AttributeName;} } 
 
        // IContextProperty::IsNewContextOK
    ///  
        public virtual bool IsNewContextOK(Context newCtx)
        {
            // This will be called before entering the newCtx
            // Default implementation says OK. 
            return true;
        } 
 
        // IContextProperty::Freeze
        // Default implementation does nothing 
    /// 
        public virtual void Freeze(Context newContext)
        {
            BCLDebug.Log("ContextAttribute::ContextProperty::Freeze"+ 
                        " for context " + newContext );
        } 
 
        // Object::Equals
        // Default implementation just compares the names 
    /// 
        public override bool Equals(Object o)
        {
            IContextProperty prop = o as IContextProperty; 
            return  (null != prop) && AttributeName.Equals(prop.Name);
        } 
 
    /// 
        public override int GetHashCode() 
        {
            return this.AttributeName.GetHashCode();
        }
 
        // IContextAttribute::IsContextOK
        // Default calls Object::Equals on the property and does not 
        // bother with the ctorMsg. 
    /// 
        public virtual bool IsContextOK( 
            Context ctx, IConstructionCallMessage ctorMsg)
        {
            if (ctx == null)
                throw new ArgumentNullException("ctx"); 
            if (ctorMsg == null)
                throw new ArgumentNullException("ctorMsg"); 
 
            BCLDebug.Assert(ctorMsg.ActivationType.IsMarshalByRef, "Activation on a non MarshalByRef object");
 
            if (!ctorMsg.ActivationType.IsContextful)
            {
                return true;
            } 

            Object prop = ctx.GetProperty(AttributeName); 
            if ((prop!=null) && (Equals(prop))) 
            {
                return true; 
            }
            return false;
        }
 
        // IContextAttribute::GetPropertiesForNewContext
        // Default adds the attribute itself w/o regard to the current 
        // list of properties 
    /// 
        public virtual void GetPropertiesForNewContext( 
            IConstructionCallMessage ctorMsg)
        {
            if (ctorMsg == null)
                throw new ArgumentNullException("ctorMsg"); 
            ctorMsg.ContextProperties.Add((IContextProperty)this);
        } 
    } 

#if SIMPLEXAACTIVATION 
    /// 
        [AttributeUsage(AttributeTargets.Class)]
[System.Runtime.InteropServices.ComVisible(true)]
    public class new_appdomain : ContextAttribute 
    {
 
        internal static int _domain_no = 0; 

    ///  
        public new_appdomain() : base("new_appdomain") {}

    /// 
[System.Runtime.InteropServices.ComVisible(true)] 
        public override bool IsContextOK(Context ctx, IConstructionCallMessage msg)
        { 
            return false; 
        }
 
    /// 
[System.Runtime.InteropServices.ComVisible(true)]
        public override void GetPropertiesForNewContext(IConstructionCallMessage ctorMsg)
        { 
            ctorMsg.GetProperties()["__new_appdomain"] = true;
        } 
 
    /// 
[System.Runtime.InteropServices.ComVisible(true)] 
        public static IConstructionReturnMessage DoSimpleXADActivation(IConstructionCallMessage msg)
        {
            int domain_no = Interlocked.Increment(ref _domain_no);
            AppDomain ad = AppDomain.CreateDomain("AutoDomain #" + domain_no, null, null); 

            activator a = (activator) (ad.CreateInstance(null, typeof(activator).FullName)).Unwrap(); 
 
            return a.Activate(msg);
        } 

    /// 
[System.Runtime.InteropServices.ComVisible(true)]
        public class activator : MarshalByRefObject, IActivator 
        {
        ///  
[System.Runtime.InteropServices.ComVisible(true)] 
            public IConstructionReturnMessage Activate(IConstructionCallMessage msg)
            { 
                return RemotingServices.DoCrossContextActivation(msg);
            }

        ///  
            [MethodImplAttribute(MethodImplOptions.NoInlining)] // Methods containing StackCrawlMark local var has to be marked non-inlineable
            public void LoadAssembly(AssemblyName an) 
            { 
                StackCrawlMark stackMark = StackCrawlMark.LookForMyCaller;
                Assembly a = Assembly.InternalLoad(an, false, null, ref stackMark); 
                if (a == null)
                {
                    throw new RemotingException(
                        String.Format( 
                            Environment.GetResourceString(
                                "Remoting_AssemblyLoadFailed"), 
                            an)); 
                }
            } 
        }
    }

    ///  
        [new_appdomain]
[System.Runtime.InteropServices.ComVisible(true)] 
        public class MBR : MarshalByRefObject 
        {
        ///  
            public String MyAppDomain()
            {
                return Thread.GetDomain().GetFriendlyName();
            } 
        }
 
    ///  
        [new_appdomain]
[System.Runtime.InteropServices.ComVisible(true)] 
        public class CB : ContextBoundObject
        {
        /// 
            public String MyAppDomain() 
            {
                return Thread.GetDomain().GetFriendlyName(); 
            } 
        }
#endif 

}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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