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The Labs \ Source Viewer \ SSCLI \ System.Runtime.Remoting.Channels \ CrossContextChannel

SSCLI

// ==++==
//
//
//
// The use and distribution terms for this software are contained in the file
// named license.txt, which can be found in the root of this distribution.
// By using this software in any fashion, you are agreeing to be bound by the
// terms of this license.
//
// You must not remove this notice, or any other, from this software.
//
//
// ==--==
//
// Remoting Infrastructure Sink for making calls across context
// boundaries.
//
namespace System.Runtime.Remoting.Channels
{
using System;
using System.Collections;
using System.Threading;
using System.Runtime.Remoting;
using System.Runtime.Remoting.Contexts;
using System.Runtime.Remoting.Messaging;
using System.Runtime.Serialization;
/* package scope */
// deliberately not [serializable]
internal class CrossContextChannel : InternalSink, IMessageSink
{
private const string _channelName = "XCTX";
private const int _channelCapability = 0;
private const string _channelURI = "XCTX_URI";
private static CrossContextChannel messageSink {
get { return Thread.GetDomain().RemotingData.ChannelServicesData.xctxmessageSink; }
set { Thread.GetDomain().RemotingData.ChannelServicesData.xctxmessageSink = value; }
}
private static object staticSyncObject = new object();
private static InternalCrossContextDelegate s_xctxDel = new InternalCrossContextDelegate(SyncProcessMessageCallback);
static internal IMessageSink MessageSink {
get {
if (messageSink == null) {
CrossContextChannel tmpSink = new CrossContextChannel();
lock (staticSyncObject) {
if (messageSink == null) {
messageSink = tmpSink;
}
}
//Interlocked.CompareExchange(out messageSink, tmpSink, null);
}
return messageSink;
}
}
static internal object SyncProcessMessageCallback(object[] args)
{
IMessage reqMsg = args[0] as IMessage;
Context srvCtx = args[1] as Context;
IMessage replyMsg = null;
// If profiling of remoting is active, must tell the profiler that we have received
// a message.
if (RemotingServices.CORProfilerTrackRemoting()) {
Guid g = Guid.Empty;
if (RemotingServices.CORProfilerTrackRemotingCookie()) {
object obj = reqMsg.Properties["CORProfilerCookie"];
if (obj != null) {
g = (Guid)obj;
}
}
RemotingServices.CORProfilerRemotingServerReceivingMessage(g, false);
}
Message.DebugOut("::::::::::::::::::::::::: CrossContext Channel: passing to ServerContextChain");
// Server side notifications for dynamic sinks are done
// in the x-context channel ... this is to maintain
// symmetry of the point of notification between
// the client and server context
// bCliSide
// bStart
// bAsync
srvCtx.NotifyDynamicSinks(reqMsg, false, true, false, true);
// bNotifyGlobals
replyMsg = srvCtx.GetServerContextChain().SyncProcessMessage(reqMsg);
// bCliSide
// bStart
// bAsync
srvCtx.NotifyDynamicSinks(replyMsg, false, false, false, true);
// bNotifyGlobals
Message.DebugOut("::::::::::::::::::::::::: CrossContext Channel: back from ServerContextChain");
// If profiling of remoting is active, must tell the profiler that we are sending a
// reply message.
if (RemotingServices.CORProfilerTrackRemoting()) {
Guid g;
RemotingServices.CORProfilerRemotingServerSendingReply(out g, false);
if (RemotingServices.CORProfilerTrackRemotingCookie()) {
replyMsg.Properties["CORProfilerCookie"] = g;
}
}
return replyMsg;
}
public virtual IMessage SyncProcessMessage(IMessage reqMsg)
{
object[] args = new object[] {null, null};
IMessage replyMsg = null;
try {
Message.DebugOut("\n::::::::::::::::::::::::: CrossContext Channel: Sync call starting");
IMessage errMsg = ValidateMessage(reqMsg);
if (errMsg != null) {
return errMsg;
}
ServerIdentity srvID = GetServerIdentity(reqMsg);
Message.DebugOut("Got Server identity \n");
BCLDebug.Assert(null != srvID, "null != srvID");
BCLDebug.Assert(null != srvID.ServerContext, "null != srvID.ServerContext");
args[0] = reqMsg;
args[1] = srvID.ServerContext;
replyMsg = (IMessage)Thread.CurrentThread.InternalCrossContextCallback(srvID.ServerContext, s_xctxDel, args);
}
catch (Exception e) {
Message.DebugOut("Arrgh.. XCTXSink::throwing exception " + e + "\n");
replyMsg = new ReturnMessage(e, (IMethodCallMessage)reqMsg);
if (reqMsg != null) {
((ReturnMessage)replyMsg).SetLogicalCallContext((LogicalCallContext)reqMsg.Properties[Message.CallContextKey]);
}
}
Message.DebugOut("::::::::::::::::::::::::::: CrossContext Channel: Sync call returning!!\n");
return replyMsg;
}
static internal object AsyncProcessMessageCallback(object[] args)
{
AsyncWorkItem workItem = null;
IMessage reqMsg = (IMessage)args[0];
IMessageSink replySink = (IMessageSink)args[1];
Context oldCtx = (Context)args[2];
Context srvCtx = (Context)args[3];
IMessageCtrl msgCtrl = null;
// we use the work item just as our replySink in this case
if (replySink != null) {
workItem = new AsyncWorkItem(replySink, oldCtx);
}
Message.DebugOut("::::::::::::::::::::::::: CrossContext Channel: passing to ServerContextChain");
// bCliSide
// bStart
// bAsync
srvCtx.NotifyDynamicSinks(reqMsg, false, true, true, true);
// bNotifyGlobals
// call the server context chain
msgCtrl = srvCtx.GetServerContextChain().AsyncProcessMessage(reqMsg, (IMessageSink)workItem);
// Note: for async calls, we will do the return notification
// for dynamic properties only when the async call
// completes (i.e. when the replySink gets called)
Message.DebugOut("::::::::::::::::::::::::: CrossContext Channel: back from ServerContextChain");
return msgCtrl;
}
public virtual IMessageCtrl AsyncProcessMessage(IMessage reqMsg, IMessageSink replySink)
{
Message.DebugOut("::::::::::::::::::::::::::: CrossContext Channel: Async call starting!!\n");
// One way Async notifications may potentially pass a null reply sink.
IMessage errMsg = ValidateMessage(reqMsg);
object[] args = new object[] {null, null, null, null};
IMessageCtrl msgCtrl = null;
if (errMsg != null) {
if (replySink != null) {
replySink.SyncProcessMessage(errMsg);
}
}
else {
ServerIdentity srvID = GetServerIdentity(reqMsg);
// If active, notify the profiler that an asynchronous remoting message was received.
if (RemotingServices.CORProfilerTrackRemotingAsync()) {
Guid g = Guid.Empty;
if (RemotingServices.CORProfilerTrackRemotingCookie()) {
object obj = reqMsg.Properties["CORProfilerCookie"];
if (obj != null) {
g = (Guid)obj;
}
}
RemotingServices.CORProfilerRemotingServerReceivingMessage(g, true);
// Only wrap the replySink if the call wants a reply
if (replySink != null) {
// Now wrap the reply sink in our own so that we can notify the profiler of
// when the reply is sent. Upon invocation, it will notify the profiler
// then pass control on to the replySink passed in above.
IMessageSink profSink = new ServerAsyncReplyTerminatorSink(replySink);
// Replace the reply sink with our own
replySink = profSink;
}
}
Context srvCtx = srvID.ServerContext;
if (srvCtx.IsThreadPoolAware) {
// this is the case when we do not queue the work item since the
// server context claims to be doing its own threading.
args[0] = reqMsg;
args[1] = replySink;
args[2] = Thread.CurrentContext;
args[3] = srvCtx;
InternalCrossContextDelegate xctxDel = new InternalCrossContextDelegate(AsyncProcessMessageCallback);
msgCtrl = (IMessageCtrl)Thread.CurrentThread.InternalCrossContextCallback(srvCtx, xctxDel, args);
}
else {
AsyncWorkItem workItem = null;
// This is the case where we take care of returning the calling
// thread asap by using the ThreadPool for completing the call.
// we use a more elaborate WorkItem and delegate the work to the thread pool
workItem = new AsyncWorkItem(reqMsg, replySink, Thread.CurrentContext, srvID);
WaitCallback threadFunc = new WaitCallback(workItem.FinishAsyncWork);
// Note: Dynamic sinks are notified in the threadFunc
ThreadPool.QueueUserWorkItem(threadFunc);
}
}
Message.DebugOut("::::::::::::::::::::::::::: CrossContext Channel: Async call returning!!\n");
return msgCtrl;
}
// AsyncProcessMessage
static internal object DoAsyncDispatchCallback(object[] args)
{
AsyncWorkItem workItem = null;
IMessage reqMsg = (IMessage)args[0];
IMessageSink replySink = (IMessageSink)args[1];
Context oldCtx = (Context)args[2];
Context srvCtx = (Context)args[3];
IMessageCtrl msgCtrl = null;
// we use the work item just as our replySink in this case
if (replySink != null) {
workItem = new AsyncWorkItem(replySink, oldCtx);
}
Message.DebugOut("::::::::::::::::::::::::: CrossContext Channel: passing to ServerContextChain");
// call the server context chain
msgCtrl = srvCtx.GetServerContextChain().AsyncProcessMessage(reqMsg, (IMessageSink)workItem);
Message.DebugOut("::::::::::::::::::::::::: CrossContext Channel: back from ServerContextChain");
return msgCtrl;
}
static internal IMessageCtrl DoAsyncDispatch(IMessage reqMsg, IMessageSink replySink)
{
object[] args = new object[] {null, null, null, null};
ServerIdentity srvID = GetServerIdentity(reqMsg);
// If active, notify the profiler that an asynchronous remoting message was received.
if (RemotingServices.CORProfilerTrackRemotingAsync()) {
Guid g = Guid.Empty;
if (RemotingServices.CORProfilerTrackRemotingCookie()) {
object obj = reqMsg.Properties["CORProfilerCookie"];
if (obj != null)
g = (Guid)obj;
}
RemotingServices.CORProfilerRemotingServerReceivingMessage(g, true);
// Only wrap the replySink if the call wants a reply
if (replySink != null) {
// Now wrap the reply sink in our own so that we can notify the profiler of
// when the reply is sent. Upon invocation, it will notify the profiler
// then pass control on to the replySink passed in above.
IMessageSink profSink = new ServerAsyncReplyTerminatorSink(replySink);
// Replace the reply sink with our own
replySink = profSink;
}
}
IMessageCtrl msgCtrl = null;
Context srvCtx = srvID.ServerContext;
//if (srvCtx.IsThreadPoolAware)
//{
// this is the case when we do not queue the work item since the
// server context claims to be doing its own threading.
args[0] = reqMsg;
args[1] = replySink;
args[2] = Thread.CurrentContext;
args[3] = srvCtx;
InternalCrossContextDelegate xctxDel = new InternalCrossContextDelegate(DoAsyncDispatchCallback);
msgCtrl = (IMessageCtrl)Thread.CurrentThread.InternalCrossContextCallback(srvCtx, xctxDel, args);
//}
return msgCtrl;
}
// DoDispatch
public IMessageSink NextSink {
// We are a terminating sink for this chain.
get { return null; }
}
}
/* package */
internal class AsyncWorkItem : IMessageSink
{
// the replySink passed in to us in AsyncProcessMsg
private IMessageSink _replySink;
// the server identity we are calling
private ServerIdentity _srvID;
// the original context of the thread calling AsyncProcessMsg
private Context _oldCtx;
private LogicalCallContext _callCtx;
// the request msg passed in
private IMessage _reqMsg;
internal AsyncWorkItem(IMessageSink replySink, Context oldCtx) : this(null, replySink, oldCtx, null)
{
}
internal AsyncWorkItem(IMessage reqMsg, IMessageSink replySink, Context oldCtx, ServerIdentity srvID)
{
_reqMsg = reqMsg;
_replySink = replySink;
_oldCtx = oldCtx;
_callCtx = CallContext.GetLogicalCallContext();
_srvID = srvID;
}
static internal object SyncProcessMessageCallback(object[] args)
{
IMessageSink replySink = (IMessageSink)args[0];
IMessage msg = (IMessage)args[1];
return replySink.SyncProcessMessage(msg);
}
public virtual IMessage SyncProcessMessage(IMessage msg)
{
// This gets called when the called object finishes the AsyncWork...
// This is called irrespective of whether we delegated the initial
// work to a thread pool thread or not. Quite likely it will be
// called on a user thread (i.e. a thread different from the
// forward call thread)
// we just switch back to the old context before calling
// the next replySink
IMessage retMsg = null;
if (_replySink != null) {
// This assert covers the common case (ThreadPool)
// and checks that the reply thread for the async call
// indeed emerges from the server context.
BCLDebug.Assert((_srvID == null) || (_srvID.ServerContext == Thread.CurrentContext), "Thread expected to be in the server context!");
// Call the dynamic sinks to notify that the async call
// has completed
// this is the async reply
// bCliSide
// bStart
// bAsync
Thread.CurrentContext.NotifyDynamicSinks(msg, false, false, true, true);
// bNotifyGlobals
object[] args = new object[] {_replySink, msg};
InternalCrossContextDelegate xctxDel = new InternalCrossContextDelegate(SyncProcessMessageCallback);
retMsg = (IMessage)Thread.CurrentThread.InternalCrossContextCallback(_oldCtx, xctxDel, args);
}
return retMsg;
}
public virtual IMessageCtrl AsyncProcessMessage(IMessage msg, IMessageSink replySink)
{
// Can't call the reply sink asynchronously!
throw new NotSupportedException(Environment.GetResourceString("NotSupported_Method"));
}
public IMessageSink NextSink {
get { return _replySink; }
}
static internal object FinishAsyncWorkCallback(object[] args)
{
AsyncWorkItem This = (AsyncWorkItem)args[0];
Context srvCtx = This._srvID.ServerContext;
LogicalCallContext threadPoolCallCtx = CallContext.SetLogicalCallContext(This._callCtx);
// Call the server context chain Async. We provide workItem as our
// replySink ... this will cause the replySink.ProcessMessage
// to switch back to the context of the original caller thread.
// Call the dynamic sinks to notify that the async call
// is starting
// bCliSide
// bStart
// bAsync
srvCtx.NotifyDynamicSinks(This._reqMsg, false, true, true, true);
// bNotifyGlobals
IMessageCtrl ctrl = srvCtx.GetServerContextChain().AsyncProcessMessage(This._reqMsg, (IMessageSink)This);
// change back to the old context
CallContext.SetLogicalCallContext(threadPoolCallCtx);
return null;
}
/* package */
internal virtual void FinishAsyncWork(object stateIgnored)
{
InternalCrossContextDelegate xctxDel = new InternalCrossContextDelegate(FinishAsyncWorkCallback);
object[] args = new object[] {this};
Thread.CurrentThread.InternalCrossContextCallback(_srvID.ServerContext, xctxDel, args);
}
}
}