3 files changed, 26 insertions, 4 deletions
diff --git a/cpp/src/slice2cs/Gen.cpp b/cpp/src/slice2cs/Gen.cpp
index 6d0b6f75272..b52f544a4ad 100755
--- a/cpp/src/slice2cs/Gen.cpp
+++ b/cpp/src/slice2cs/Gen.cpp
@@ -3360,7 +3360,6 @@ Slice::Gen::HelperVisitor::visitClassDefStart(const ClassDefPtr& p)
 
 	    _out << nl << "public void " << opName << "_async" << spar << paramsAMI << "Ice.Context ctx__" << epar;
 	    _out << sb;
-	    _out << nl << "checkTwowayOnly__(\"" << p->name() << "\");";
 	    _out << nl << "cb__.invoke__" << spar << "this" << argsAMI << "ctx__" << epar << ';';
 	    _out << eb;
 	}
@@ -4312,6 +4311,15 @@ Slice::Gen::AsyncVisitor::visitOperation(const OperationPtr& p)
 	_out << nl << "try";
 	_out << sb;
 	_out << nl << "prepare__(prx__, \"" << name << "\", " << sliceModeToIceMode(p) << ", ctx__);";
+	if(p->returnsData())
+	{
+	    _out << nl << "if(!prx__.ice_isTwoway())";
+	    _out << sb;
+	    _out << nl << "Ice.TwowayOnlyException ex = new Ice.TwowayOnlyException();";
+	    _out << nl << "ex.operation = \"" << name << "\";";
+	    _out << nl << "throw ex;";
+	    _out << eb;
+	}
 	for(q = inParams.begin(); q != inParams.end(); ++q)
 	{
 	    string typeS = typeToString(q->first);
diff --git a/cpp/src/slice2java/Gen.cpp b/cpp/src/slice2java/Gen.cpp
index 28a361c6a95..0e8418cf660 100644
--- a/cpp/src/slice2java/Gen.cpp
+++ b/cpp/src/slice2java/Gen.cpp
@@ -3127,8 +3127,6 @@ Slice::Gen::HelperVisitor::visitClassDefStart(const ClassDefPtr& p)
 	    out << nl << "public void" << nl << op->name() << "_async" << spar << paramsAMI << "java.util.Map __ctx"
 		<< epar;
 	    out << sb;
-	    // Async requests may only be sent twoway.
-	    out << nl << "__checkTwowayOnly(\"" << p->name() << "\");";
 	    out << nl << "__cb.__invoke" << spar << "this" << argsAMI << "__ctx" << epar << ';';
 	    out << eb;
 	}
@@ -4553,6 +4551,13 @@ Slice::Gen::AsyncVisitor::visitOperation(const OperationPtr& p)
 	out << nl << "try";
 	out << sb;
 	out << nl << "__prepare(__prx, \"" << p->name() << "\", " << sliceModeToIceMode(p) << ", __ctx);";
+	if(p->returnsData())
+	{
+	    out << nl << "if(!__prx.ice_isTwoway())";
+	    out << sb;
+	    out << nl << "throw new Ice.TwowayOnlyException(\"" << p->name() << "\");";
+	    out << eb;
+	}
         iter = 0;
 	for(pli = inParams.begin(); pli != inParams.end(); ++pli)
 	{
diff --git a/cpp/src/slice2vb/Gen.cpp b/cpp/src/slice2vb/Gen.cpp
index f7e6c7303d1..1eb4a0ec495 100755
--- a/cpp/src/slice2vb/Gen.cpp
+++ b/cpp/src/slice2vb/Gen.cpp
@@ -3708,7 +3708,6 @@ Slice::Gen::HelperVisitor::visitClassDefStart(const ClassDefPtr& p)
 	         << "ByVal ctx__ As Ice.Context" << epar
 	         << " Implements " << name << "Prx." << opName << "_async"; // TODO: should be containing class?
 	    _out.inc();
-	    _out << nl << "checkTwowayOnly__(\"" << p->name() << "\")";
 	    _out << nl << "cb__.invoke__" << spar << "Me" << argsAMI << "ctx__" << epar;
 	    _out.dec();
 	    _out << nl << "End Sub";
@@ -4792,6 +4791,16 @@ Slice::Gen::AsyncVisitor::visitOperation(const OperationPtr& p)
 	_out << nl << "Try";
 	_out.inc();
 	_out << nl << "prepare__(prx__, \"" << p->name() << "\", " << sliceModeToIceMode(p) << ", ctx__)";
+	if(p->returnsData())
+	{
+	    _out << nl << "If Not prx__.ice_isTwoway() Then";
+	    _out.inc();
+	    _out << nl << "Dim ex As Ice.TwowayOnlyException = New Ice.TwowayOnlyException()";
+	    _out << nl << "ex.operation = \"" << p->name() << "\"";
+	    _out << nl << "Throw ex";
+	    _out.dec();
+	    _out << nl << "End If";
+	}
 	for(q = inParams.begin(); q != inParams.end(); ++q)
 	{
 	    string typeS = typeToString(q->first);