[AWS] memory leak in AWS-based application

[Petr Holub]

Hi all,

I'm using the following SOAP_Wrapper-based code to produce one service:

        function SOAP_RequestVLAN is new Slartibartfast_Server_Operations_Service.Server.RequestVLAN_CB (RequestVLAN);
        function SOAP_RequestVLAN_Wrapper is new SOAP.Utils.SOAP_Wrapper (SOAP_RequestVLAN);
        function SOAP_GetVLANTag is new Slartibartfast_Server_Operations_Service.Server.GetVLANTag_CB (GetVLANTag);
        function SOAP_GetVLANTag_Wrapper is new SOAP.Utils.SOAP_Wrapper (SOAP_GetVLANTag);
        function SOAP_ReleaseVLAN is new Slartibartfast_Server_Operations_Service.Server.ReleaseVLAN_CB (ReleaseVLAN);
        function SOAP_ReleaseVLAN_Wrapper is new SOAP.Utils.SOAP_Wrapper (SOAP_ReleaseVLAN);
        function SOAP_AddHosts is new Slartibartfast_Server_Operations_Service.Server.AddHosts_CB (AddHosts);
        function SOAP_AddHosts_Wrapper is new SOAP.Utils.SOAP_Wrapper (SOAP_AddHosts);
        function SOAP_RemoveHosts is new Slartibartfast_Server_Operations_Service.Server.RemoveHosts_CB (RemoveHosts);
        function SOAP_RemoveHosts_Wrapper is new SOAP.Utils.SOAP_Wrapper (SOAP_RemoveHosts);

        --  generic callback that calls individual callbacks based on
        --  SOAPAction request

        function AWS_CallBack (Request : in AWS.Status.Data) return AWS.Response.Data is
                SOAPAction : constant String := AWS.Status.SOAPAction (Request);

        begin
                --  XXX: call to every SOAP.Utils.SOAP_Wrapper produces some memory leak
                if SOAPAction = "RequestVLAN" then
                        return SOAP_RequestVLAN_Wrapper (Request);
                elsif SOAPAction = "GetVLANTag" then
                        return SOAP_GetVLANTag_Wrapper (Request);
                elsif SOAPAction = "AddHosts" then
                        return SOAP_AddHosts_Wrapper (Request);
                elsif SOAPAction = "RemoveHosts" then
                        return SOAP_RemoveHosts_Wrapper (Request);
                elsif SOAPAction = "ReleaseVLAN" then
                        return SOAP_ReleaseVLAN_Wrapper (Request);
                else
                        return AWS.Response.Build (AWS.MIME.Text_HTML, "<p>Not an appropriate SOAP request!</p>");
                end if;
        end AWS_CallBack;

It looks like each call to the SOAP_*_Wrapper produces some memory leak that
builds up over the time. The reasoning why I think so is as follows:

1) watching the server slowly increases memory usage when there are
   incoming requests coming

2) when I call my own functions like RequestVLAN, GetVLANTag, etc., no
   leaks are produced even after thousands of calls

3) when the AWS_CallBack is modified as follows:

        function AWS_CallBack (Request : in AWS.Status.Data) return AWS.Response.Data is
                SOAPAction : constant String := AWS.Status.SOAPAction (Request);

        begin
                return AWS.Response.Build (AWS.MIME.Text_HTML, "<p>Not an appropriate SOAP request!</p>");
        end AWS_CallBack;

   (i.e., it doesn't do anything useful any more, just rejecting the requests),
   I can't see any memory leaks even after thousands of calls


So this leads me to believe there is some leak either in
Slartibartfast_Server_Operations_Service.Server.*_CB (autmatically generated by wsdl2ada)
or in
SOAP.Utils.SOAP_Wrapper

Any experiences with this? (Just want to avoid discovering a wheel ;) ).

Thanks a lot,
Petr