Re: Com POrt - COM Discussion Boards

LaiAlan wrote:
I am having an out of memory problem in Matlab

How have you verified this?
Did MatLab crash due to low memory or did it display a message that told you it was running low on memory?
If you base all this on the figures in Task Manager you should really have a look at this article[^].

LaiAlan wrote:
If I let it keep running, Matlab eventually runs out of memory.

Have you actually experienced this?

"It's supposed to be hard, otherwise anybody could do it!" - selfquote
"High speed never compensates for wrong direction!" - unknown

Yes, Matlab crashed due to low memory. The actual error message is:

??? Out of memory. Type HELP MEMORY for your options.

Error in ==> comeventcallback at 3
args = hEvent.get;

Warning: Error occurred while evaluating listener callback.

After it has ran out of memory and stopped "reading and clearing data" (i.e., I did it to make sure it doesn't use more and more memory), "clear" did not change the memory used by Matlab at all:

>> memory
Maximum possible array: 8 MB (8.389e+006 bytes) *
Memory available for all arrays: 69 MB (7.256e+007 bytes) **
Memory used by MATLAB: 2767 MB (2.901e+009 bytes)
Physical Memory (RAM): 3326 MB (3.487e+009 bytes)

LaiAlan wrote:
??? Out of memory. Type HELP MEMORY for your options.

Error in ==> comeventcallback at 3
args = hEvent.get;

Warning: Error occurred while evaluating listener callback.

This looks interesting. It looks like an error message from MatLab
To me it seems reasonable that such an error won't occur unless the application is trying to allocate memory. The text "Error occurred while evaluating listener callback", makes me suspect that this error occurs before your callback is called.
The above suggests that MatLab is allocating memory internally prior to calling your callback. This could be due to how the callback interface is declared.
What does the callback interface look like? Post the declaration of it.

If you don't allocate any memory in your callback and the third party DLL doesn't allocate memory when calling your callback, then it must be some kind of internal MatLab stuff that is going on and it should be possible to find in the MatLab documentation.

Have you tried writing another client to avoid MatLab related stuff with e.g. MFC?
What happens?

"It's supposed to be hard, otherwise anybody could do it!" - selfquote
"High speed never compensates for wrong direction!" - unknown

Dear Roger,

Thank you very much for your reply.

The following is a section of the code in the Connect.m function that does all the initialisation (creates the actxserver, opens the data file using a method of the DLL, creating the data reader interface and registering the event callbacks to retrieve data):

%--------------------------------------------------------------------------
% Load Study Interface (ACTUALLY, it is a COM Server in Matlab, not an
% interface).
gIStudy = actxserver('CMEEGStudyV4.Study');

% Open the study.
gIStudy.Open(FilePath,0) % File path name

% Determine the sampling rate and the number of channels in the study.
SampleRate = gIStudy.get('EEGSampleRate');
gSampleRate = SampleRate;
IChannels = gIStudy.get('Channels');
TotalChs = IChannels.count;
clear IChannels
gTotalChs = TotalChs;

% Determine how many data segments there are in the study.
IDataSegs = gIStudy.get('DataSegments');
NumDataSegs = IDataSegs.count; % A data segment is like a 'Block' in TDT.
% The data segments' start times are all referenced to a single time point.
% That is, the second data segment's start time is always later than the
% first data segment's start time plus the first data segment's duration.

% Create the Data Reader (Interface).
DataReader = gIStudy.CreateDataReader;
DataReader.registerevent({'DataReady' 'DataReady_TEST'});
DataReader.registerevent({'NoData' 'NoData_TEST'});
%--------------------------------------------------------------------------

I have a Get_Data.m function that the user specifies the start time and duration of the data required from the data file. The Get_Data.m function has a line of code that uses the data reader in the DLL to request the data:

%--------------------------------------------------------------------------
DataReader.SGetDataEx(StartSample,NumberofSamples);
while ~gDataRetrieved % gDataRetrieved is a global variable
pause(0.0001) % Stay in this while loop until all the data has been retrieved.
end
gDataRetrieved = false; % Reset the DataRetrieved flag
%--------------------------------------------------------------------------

In the event callback function (DataReady.m), all it does is read in the data:
%--------------------------------------------------------------------------
gDataMat = varargin{7}; % When a registered event is triggered, Matlab passes information
% from the event to its handler function as a cell.
% It is the 7th cell because 1-2 are Matlab stuff.
% 3-6 are some data info retrieved by the DLL.

I have narrowed down the source of the problem by using the Matlab "memory" command throughout the functions. In particular,

memory usage = 518MB
memory (i.e., "memory" command before the datareader line)
DataReader.SGetDataEx(StartSample,NumberofSamples) % This will trigger the DataReady.m to read data

memory usage = 597MB
Just as it enters the DataReady.m function (i.e., "memory" command as the 1st line of function)

memory usage = 597MB
As it exits the DataReady.m function (i.e., "memory" command as the last line of function)

memory usage = 545MB
DataReader.SGetDataEx(StartSample,NumberofSamples)
memory (i.e., "memory" command after datareader line)

So, it has leaked 545MB - 518MB = 27MB per data retrieval cycle. I think I might have mentioned it before, but using "clear" will not reduce the memory that Matlab holds up, as opposed to, say:

memory usage = 900MB
x = randn(10000,10000);
clear
memory usage = 100MB

Yes, your suggestion of using another client is an excellent idea, although I am not much of a programmer (only a little C programming from undergraduate studies, which I have forgotten). I don't know what MFC is. Will look into your suggestion.

Thanks,
Alan

Hi to all,

I am creating a IE toolbar in C#, using Band Object.
I want to get event or any attribute value, which show that is my toolbar is enable/disable in IE.Or which event/attribute of band object tell me the satus of my toolbar.

Please Help me.

Only way I know is to check registry key
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Ext\Settings\<GUID>, where <GUID> is your toolbar CLSID. If value 'Flags' exists in this key, then your toolbar is disabled. If Flags value does not exists or whole key does not exists - your toolbar is enabled.

hello
this is shikha, i m new in programming in Com Port, Actually my previous i did one project in which i have to receive/send SMS using COM1,
now the Device changed and it is supporting the Com3, Sending is working perfectly but unable to recive SMS using Port3.. here i m using Third party DLL. GSMCOMM DLL..just i m struck here,
one event is there "GsmComm.GsmCommunication.MessageReceivedEventArgs" is not firing, it should fired when message is recive BY the Port 3.. i m just unable to understand how to reslove the problem, i tried a lot, searched a lot....

<code> public partial class Receive : Form
{
private DataTable dt = new DataTable();
private delegate void SetTextCallback(string text);
System.IO.Ports.SerialPort port = new System.IO.Ports.SerialPort();
public Receive()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
Cursor.Current = Cursors.WaitCursor;

//string storage = GetMessageStorage();
string storage = PhoneStorageType.Sim;
try
{
// Read all SMS messages from the storage
DecodedShortMessage[] messages = CommSetting.comm.ReadMessages(PhoneMessageStatus.All, storage);
foreach (DecodedShortMessage message in messages)
{
Output(string.Format("Message status = {0}, Location = {1}/{2}",
StatusToString(message.Status), message.Storage, message.Index));
ShowMessage123(message.Data);
Output("");
}
Output(string.Format("{0,9} messages read.", messages.Length.ToString()));
Output("");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
Cursor.Current = Cursors.Default;
}
private void BindGrid(SmsPdu pdu)
{
DataRow dr = dt.NewRow();
SmsDeliverPdu data = (SmsDeliverPdu)pdu;
dr[0] = data.OriginatingAddress.ToString();
dr[1] = data.SCTimestamp.ToString();
dr[2] = data.UserDataText;
//dr[1] = data.UserDataText;
dt.Rows.Add(dr);
//Thread.Sleep(500);
dataGrid1.DataSource = dt;
}
SmsDeliverPdu data;
private void ShowMessage(SmsPdu pdu)
{
if (pdu is SmsSubmitPdu)
{
// Stored (sent/unsent) message
SmsSubmitPdu data = (SmsSubmitPdu)pdu;
Output("SENT/UNSENT MESSAGE");
Output("Recipient: " + data.DestinationAddress);
Output("Message text: " + data.UserDataText);
Output("-------------------------------------------------------------------");
return;
}
if (pdu is SmsDeliverPdu)
{
// Received message
data = (SmsDeliverPdu)pdu;
Output("RECEIVED MESSAGE");
Output("Sender: " + data.OriginatingAddress);
Output("Sent: " + data.SCTimestamp.ToString());
Output("Message text: " + data.UserDataText);
Output("-------------------------------------------------------------------");
//BindGrid(pdu);
return;
}
if (pdu is SmsStatusReportPdu)
{
// Status report
SmsStatusReportPdu data = (SmsStatusReportPdu)pdu;
Output("STATUS REPORT");
Output("Recipient: " + data.RecipientAddress);
Output("Status: " + data.Status.ToString());
Output("Timestamp: " + data.DischargeTime.ToString());
Output("Message ref: " + data.MessageReference.ToString());
Output("-------------------------------------------------------------------");
return;
}
Output("Unknown message type: " + pdu.GetType().ToString());
}
private void ShowMessage123(SmsPdu pdu)
{
if (pdu is SmsSubmitPdu)
{
// Stored (sent/unsent) message
SmsSubmitPdu data = (SmsSubmitPdu)pdu;
Output("SENT/UNSENT MESSAGE");
Output("Recipient: " + data.DestinationAddress);
Output("Message text: " + data.UserDataText);
Output("-------------------------------------------------------------------");
return;
}
if (pdu is SmsDeliverPdu)
{
// Received message
data = (SmsDeliverPdu)pdu;
Output("RECEIVED MESSAGE");
Output("Sender: " + data.OriginatingAddress);
Output("Sent: " + data.SCTimestamp.ToString());
Output("Message text: " + data.UserDataText);
Output("-------------------------------------------------------------------");
BindGrid(pdu);
return;
}
if (pdu is SmsStatusReportPdu)
{
// Status report
SmsStatusReportPdu data = (SmsStatusReportPdu)pdu;
Output("STATUS REPORT");
Output("Recipient: " + data.RecipientAddress);
Output("Status: " + data.Status.ToString());

Output("Timestamp: " + data.DischargeTime.ToString());
Output("Message ref: " + data.MessageReference.ToString());
Output("-------------------------------------------------------------------");
return;
}
Output("Unknown message type: " + pdu.GetType().ToString());
}
private string StatusToString(PhoneMessageStatus status)
{
// Map a message status to a string
string ret;
switch (status)
{
case PhoneMessageStatus.All:
ret = "All";
break;
case PhoneMessageStatus.ReceivedRead:
ret = "Read";
break;
case PhoneMessageStatus.ReceivedUnread:
ret = "Unread";
break;
case PhoneMessageStatus.StoredSent:
ret = "Sent";
break;
case PhoneMessageStatus.StoredUnsent:
ret = "Unsent";
break;
default:
ret = "Unknown (" + status.ToString() + ")";
break;
}
return ret;
}
private void Output(string text)
{
if (this.txtOutput.InvokeRequired)
{
SetTextCallback stc = new SetTextCallback(Output);
this.Invoke(stc, new object[] { text });
}
else
{
txtOutput.AppendText(text);
txtOutput.AppendText("\r\n");
}
}
private void Receive_Load(object sender, EventArgs e)
{
//Prompt user for connection settings
int port = 3 ;
int baudRate = 9600; // We Set 9600 as our Default Baud Rate
int timeout = 300;
//string Parity = "None";
//int DataBits = 8;
//int StopBits = 1;

TestConnection dlg = new TestConnection();
//frmConnection dlg = new frmConnection();
dlg.StartPosition = FormStartPosition.CenterScreen;
//dlg.SetData(port, baudRate, timeout,Parity,DataBits,StopBits);
dlg.SetData(port, baudRate, timeout);
if (dlg.ShowDialog(this) == DialogResult.OK)
{
dlg.GetData(out port, out baudRate, out timeout);
//dlg.GetData(out port, out baudRate, out timeout, out Parity, out DataBits, out StopBits);
CommSetting.Comm_Port = port;
CommSetting.Comm_BaudRate = baudRate;
CommSetting.Comm_TimeOut = timeout;
//CommSetting.Comm_Parity = Parity;
//CommSetting.Comm_DataBits = DataBits;
//CommSetting.Comm_StopBits = StopBits;

}
else
{
//Close();
return;
}
Cursor.Current = Cursors.WaitCursor;
CommSetting.comm = new GsmCommMain(port, baudRate, timeout);
Cursor.Current = Cursors.Default;
CommSetting.comm.MessageReceived += new MessageReceivedEventHandler(comm_MessageReceived);
bool retry;
do
{
retry = false;
try
{
Cursor.Current = Cursors.WaitCursor;
CommSetting.comm.Open();
Cursor.Current = Cursors.Default;
}
catch (Exception)
{
Cursor.Current = Cursors.Default;
if (MessageBox.Show(this, "Unable to open the port.", "Error",
MessageBoxButtons.RetryCancel, MessageBoxIcon.Warning) == DialogResult.Retry)
retry = true;
else
{
Close();
return;
}
}
}
while (retry);
//Prompt user for connection settings

dt.Columns.Add("Number", typeof(string));
dt.Columns.Add("Time", typeof(string));
dt.Columns.Add("Message", typeof(string));

}
private void comm_MessageReceived(object sender, GsmComm.GsmCommunication.MessageReceivedEventArgs e)
{
MessageReceived();
}

bool _flagNumber;
bool _FlagName;
int i;
private void MessageReceived()
{
Cursor.Current = Cursors.WaitCursor;
string storage = PhoneStorageType.Sim;
int port = 3;
int baudRate = 9600;

int timeout = GsmCommMain.DefaultTimeout;
// string Parity = "None";
//int DataBits = 8;
//int StopBits = 1;
TestConnection dlg = new TestConnection();
//frmConnection dlg = new frmConnection();
dlg.StartPosition = FormStartPosition.CenterScreen;
dlg.SetData(port, baudRate, timeout);
dlg.GetData(out port, out baudRate, out timeout);
//dlg.SetData(port, baudRate, timeout, Parity, DataBits, StopBits);
//dlg.GetData(out port, out baudRate, out timeout, out Parity, out DataBits, out StopBits);
CommSetting.Comm_Port = port;
CommSetting.Comm_BaudRate = baudRate;
CommSetting.Comm_TimeOut = timeout;
DecodedShortMessage[] messages = CommSetting.comm.ReadMessages(PhoneMessageStatus.ReceivedUnread, storage);
foreach (DecodedShortMessage message in messages)
{
Output(string.Format("Message status = {0}, Location = {1}/{2}",
StatusToString(message.Status), message.Storage, message.Index));
ShowMessage(message.Data);
Output("");
SMS si = new SMS();
SmsBL SmsBal = new SmsBL();
si.OrderDateTime = data.SCTimestamp.ToDateTime().ToShortDateString();
si.OrderFrom = data.OriginatingAddress;

si.OrderMsg = data.UserDataText;
si.ReadStatus = "Read";
si.OrderStatus = "Active";
SmsBal.InsertSMSDetails(si);
SMS sms1 = new SMS();
SmsBL smsbal = new SmsBL();
//sms1.Number = data.OriginatingAddress.ToString();

//string _strMessage = smsbal.InsertNumber(si);
SmsSubmitPdu AutoSend = new SmsSubmitPdu();
try
{
DataTable dt = new DataTable();
dt = smsbal.GetNumber();
DataTable dt1 = new DataTable();
dt1 = smsbal.GetDealer();

for ( i=0; i<=dt.Rows.Count-1;i++)
{
if (dt.Rows[i].ItemArray[0].ToString() == data.OriginatingAddress.ToString())
{
_flagNumber = true;
}
}
if (_flagNumber)
{
for (int j = 0; j <= dt1.Rows.Count - 1; j++)
{
string name=dt1.Rows[j].ItemArray[1].ToString();
if (name.ToUpper()== data.UserDataText.ToUpper())
{

_FlagName = true;
AutoSend = new SmsSubmitPdu( "Transaction Amount is:"+dt1.Rows[j].ItemArray[4].ToString(), data.OriginatingAddress, string.Empty);
CommSetting.comm.SendMessage(AutoSend);
}

}

}
else
{
MessageBox.Show("SMS Not Registered");

}

if (!_FlagName)
{
MessageBox.Show("Invaild SMS","Read Message",MessageBoxButtons.OK,MessageBoxIcon.Information );
//AutoSend = new SmsSubmitPdu(dt1.Rows[i].ItemArray[4].ToString(), data.OriginatingAddress, string.Empty);
//CommSetting.comm.SendMessage(AutoSend);

}
//else
//{
// MessageBox.Show("Invaild SMS");
//}
}

catch (Exception ex)
{
Output(ex.Message);
}

}
Output(string.Format("{0,9} messages read.", messages.Length.ToString()));
Output("");

}
private void Output(string text, params object[] args)
{
string msg = string.Format(text, args);
Output(msg);
}
private void button1_Click_1(object sender, EventArgs e)
{
Cursor.Current = Cursors.WaitCursor;

//string storage = GetMessageStorage();
string storage = PhoneStorageType.Sim;
try
{
// Read all SMS messages from the storage
DecodedShortMessage[] messages = CommSetting.comm.ReadMessages(PhoneMessageStatus.All, storage);
foreach (DecodedShortMessage message in messages)
{
Output(string.Format("Message status = {0}, Location = {1}/{2}",
StatusToString(message.Status), message.Storage, message.Index));
ShowMessage123(message.Data);
Output("");
}
Output(string.Format("{0,9} messages read.", messages.Length.ToString()));
Output("");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
Cursor.Current = Cursors.Default;
}
private void Receive_FormClosing(object sender, FormClosingEventArgs e)
{
// Clean up comm object
if (CommSetting.comm != null)
{
// Unregister events
///CommSetting.comm.PhoneConnected -= new EventHandler(comm_PhoneConnected);
CommSetting.comm.MessageReceived -= new MessageReceivedEventHandler(comm_MessageReceived);

// Close connection to phone
if (CommSetting.comm != null && CommSetting.comm.IsOpen())
CommSetting.comm.Close();
CommSetting.comm = null;
}

}
}
} </code>

plzzzzzz help me!!!!!!!!!!!!!!!!!!

Shikha,

your post is so wonderfully misplaced I just cannot refrain from answering.... Blush | :O

1. Wrong forum
This forum is about COM, as in Component Object Model[^], and not about COMmunication ports.

2. Wrong forum #2
Even if this forum was dedicated to COMmunication ports, your post isn't really about how to use the COM port for reading and writing; your post is about a third party DLL that perhaps someone has used, but don't count on it. You' d probably be better off asking the "third party" why your application, and/or the DLL, misbehaves.
If it was really about COM ports, you should have a look at this excellent article[^].
Even though you seem to use C#, which I'm not familiar with, the Win32 API calls mentioned in the article is still the same as well as the concept of "how to do serial port programming".

3. Debug your application
Prior to posting a lot of code that you hope someone will debug (for free) and pinpoint what you have done wrong, you should debug it yourself. It would increase your skills, you'd get to know your own code and why it behaves the way it does. It may come to a point where you expect a certain behaviour that you don't experience, get stuck and start posting questions in forums like this one. But the explanation of the problem has to be more detailed than "it doesn't work, here's the code, please help me".

4. Use code formatting tags
The code you've posted is very hard to read.
It looks like you've tried to format the code you've posted, but you've probably checked the "Do not interpret HTML tags..." checkbox below the text input box when writing your post.
Tip of the day: preview your post before you send it.

Your post has been down voted for the above reasons.
It wasn't by me, but it could have been.

"It's supposed to be hard, otherwise anybody could do it!" - selfquote
"High speed never compensates for wrong direction!" - unknown

I need a help regarding OLE objects instantiaton and termination.
I have a trial application which uses a dll which uses global instances of OLE pointers of an application as given below

FMApplication *fmApp = NULL;
FMCase *fmCase = NULL;

CoInitialize is called during DLL_PROCESS_ATTACH and the above OLE objects are instantiated henceforth. However, on exit of the application, the process hangs saying issue with OLE pointers. I tried releasing OLE instance in DLL_PROCESS_DETACH. Somehow OLE instances could not release and hangs there. I have ensured CoUninitialize is not called anywhere before OLE instance Release.

fmApp->Release(); //Fails here
fmApp = NULL;

fmCase->Release();
fmCase = NULL;

Do you know this (MSDN [^])

Because there is no way to control the order in which in-process servers are loaded or unloaded, do not call CoInitialize, CoInitializeEx, or CoUninitialize from the DllMain function.

?

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

To expand on CPallini's ansawer - here's Larry Osterman and Raymond Chen[^] on the subject - and they are two Windows guys who should know the real deal!

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

hi,
can any body tell how can i add .dll for my application(c#.net) because it can not directly added from add references( neither .net nor from com component)

so i want to add dll through command prompt
i edit c:\>regsvr "c:\BAS\bin\Deug\BAS_DAL.dll"

BUT IT PRODUCE MESSAGE
" C:\BAS\bin\Deug\BAS_DAL.dll was loaded but the DllRegisterServer entry point was noy found, DllRegisterServer may not be exported "

HOW CAN ADD I .dll to my project through command prompt or Other way

from :-Jaydeep Bhatt

If you wrote the DLL in (say) C++, then you probably need to use PInvoke - here's an introduction[^].

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Hi,

If your dll has .Net framework dependency then try the following,
Go to .Net command prompt and enter the command below,
RegAsm yourDll.dll /tlb:yourDll.tlb /codebase
Note: It will register in to GAC & export tlb.

Thanks

Md. Marufuzzaman

Md. Marufuzzaman wrote:
your dll

It's NOT my DLL - can I suggest yuou reply to the OP, rather than to my reply to him - he ain't going to read your message otherwise...

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

If the dll you want to add is not (yet) registered you might find it through "add references" --> choose the "search" tab and search your path to the dll. In case you change that path you have to correct your reference as well.

BTW some dlls you don't register with regsvr32 but with regasm.

Regards
Michael

Hi,

I want to redirect JavaScript functions (such as alert, open etc) calls to be redirected to my code written in C++. I launch IE from my application that implements an event sink to listen to various events by IE.

- I have inherited a class from IDispatch and implemented only Invoke that handles DISPID_VALUE.
- The next thing i did is call Invoke using my class dispatch pointer with DISPID_VALUE.
- After that i get dispid to the function (say alert()) in global scripting object whose call i want to redirect to my class.
- Using this dispid as the parameter, i call Invoke with global scripting object retrieved from get_Script().
- Doing so gives me error DISP_E_BADVARTYPE (bad variable type).

Following is the code:

//==============================
CComObject<cmycomobj> *pObj = NULL;

DISPPARAMS dispparams, dispparamsNoArgs = {NULL, NULL, 0, 0};
VARIANT var;
dispparams.rgvarg=NULL;
dispparams.rgdispidNamedArgs=NULL;
dispparams.cArgs=0;
dispparams.cNamedArgs=0;

//Create my class object.
pObj->CreateInstance(&pObj);
pObj->QueryInterface(IID_IUnknown, (void **) &punkTemp);
hr = punkTemp->QueryInterface(IID_IDispatch, (void **) &pDispMyObj);

//Call invoke to get the required info from parameters passed.
hr = pDispMyObj->Invoke(DISPID_VALUE, IID_NULL, LOCALE_USER_DEFAULT, DISPATCH_PROPERTYGET,
&dispparams, &var, NULL, NULL);

//Get global scripting object DispatchEx pointer
m_spInetExplorer-&get_Document(&pDisp);
pDisp->QueryInterface(IID_IHTMLDocument2, (void **) &pHTMLDocument2);
pHTMLDocument2->get_Script(&pDispSE);
pDispSE->QueryInterface(IID_IDispatchEx, (void **) &DispExSE);

//Set arguments that will be sent with the invoke call below.
DISPID putid = DISPID_PROPERTYPUT;
dispparams.rgvarg = &var;
dispparams.rgdispidNamedArgs = &putid;
dispparams.cArgs = 1;
dispparams.cNamedArgs = 1;

BSTR strOpen = SysAllocString(OLESTR("alert"));
DISPID dispIDAlert;

//Get dispid of the function that is to be hooked in this case alert().
hr = pDispExSE->GetDispID(strOpen, fdexNameEnsure, &dispIDAlert);

//Here it returns the error DISP_E_BADVARTYPE.
//Call invoke with DISPATCH_PROPERTYPUT to install hooks.
hr = pDispExSE->InvokeEx(dispIDAlert, LOCALE_USER_DEFAULT, DISPATCH_PROPERTYPUT, &dispparams,
NULL, NULL, NULL);
//==============================

Please let me know if such a thing is possible. If so then is this the right way to achieve this? What am i doing wrong here?

Thanks for your help.

I have made some progress in hooking the global scripting engine. When a call to a JS function such as alert, open etc (or which ever function i have hooked) is made then call first lands at my c++ code. Currently there are some stability issues and i am looking into their possible resolutions. I will keep on updating this thread until the issue is resolved (or someone help me resolve it which BTW seems highly unlikely at this forum). This would be helpful for those who want to do a similar thing and dont know where to start.

Please post the code you already have. I am very interested in this and would be able to test it in my app.
Chris.

I have a WMI provider, which will be extending the Win32_DiskDrive class. My WMI class name is "TL_PhysicalDisk" in namespace "TLV2", at the time of enumerating the instances I am trying to enumerate the Win32_DiskDrive, for this I am doing following:
a) Creating a CWbemLocator object
b) Connecting to "root\CIMV2" namespace and getting the CWbemServices object

Problem: I am not getting the enumeration of Win32_DiskDrive inside my provider, though I can see the list in WMI Object Browser.

Is there something else which needs to be done for accessing a different namespace than that of WMI Proivder from inside the provider?

Without looking at relavant portions of your source code, we will be guessing at solutions to your problem. Where does your code fail?
By the way, I just read through your previous post and the suggestions of Stuart Dootson. I've read most of his posts, and he is a much more knowledgable programmer than I am.
...so, I hope he leaps in.

In my code for WMI Provider, I am trying access a different namespace. My current namespace is "TLV2" and I need to read the disk values from "CIMV2". The method Next() of object IEnumWbemClassObject returns me an WBEM_E_ACCESS_DENIED.

Both the providers hosting model is same "NetworkServiceHost", within my provider source I am initialzing WMI for calls to "CIMV2". I figure this is something to do with the impersonation or security, though the hosting models are same but the windows processes are different. The code for initializing WMI is as follows;

bool CWMI::InitializeWMI(IWbemContext *pCtx)
{
      HRESULT hr;
      IsConnected = false;

      hr = CoCreateInstance(CLSID_WbemLocator, 0, CLSCTX_INPROC_SERVER, IID_IWbemLocator, (LPVOID *) &WbemLocator);
      if (FAILED(hr)) {
            CoUninitialize();
      }
      else{
            if(SUCCEEDED(hr) && WbemLocator != NULL){
                  hr = WbemLocator->ConnectServer( BSTR(L"root\\cimv2"), NULL, NULL, 0, NULL, 0,pCtx, &WbemServices);
                  if (FAILED(hr)){
                        WbemLocator->Release();
                        CoUninitialize();
                  }
                  else{
                        if(SUCCEEDED(hr))
                        {
                              hr = CoSetProxyBlanket(WbemServices, RPC_C_AUTHN_WINNT, RPC_C_AUTHZ_NONE,NULL, RPC_C_AUTHN_LEVEL_CALL, RPC_C_IMP_LEVEL_IMPERSONATE, NULL, EOAC_NONE);
                              if (FAILED(hr)) {
                                    WbemServices->Release();
                                    WbemLocator->Release();
                                    CoUninitialize();
                              }
                              else{
                                    IsConnected = true;
                              }
                        }
                  }
            }
      }
      return(IsConnected);
}

You know, I've read through Don Box's section on COM security in "Essential COM" numerous times,...and, I'm embarrassed to admit it, but, it still confuses the hell out of me.
...But, you should probably read this over at MSDN: Impersonating a Client[^], especially the section entitled, Handling Access Denied Messages in a Provider[^].
I noticed you don't call CoInitializeSecurity[^].
What you need to do is query the security settings, and since WMI runs as an out of process server, I'm thinking the appropriate function would be: CoQueryProxyBlanket[^]. There are several COM interfaces available specifically for this purpose (see end of this post). But, honestly, I'm not sure and I don't have Don Box's "Essential COM" with me.
This might be useful. I found an explanation of COM Security in Chapter 18, COM Security[^], "Inside COM+". It explains the COM security model in great detail, especially impersonation levels and how to query COM security settings, both with the Distributed COM Configuration Utility and programatically. All the good stuff is near the end of the chapter.
...And, if you're STILL confused, try: MSDN, Security in COM reference[^].

Thanks for the pointers, I guess you are right. I am shooting in dark, I will go through the book by Don Box.

Well since I am calling WMI from inside a WMI Provider calling CoInitializeSecurity[^] gives me error. Let me check out the CoQueryProxyBlanket[^].

I couldn't get back since I don't have a internet connection at me residence, it will get up and running this weekend. Hopefully then there won't be such a long gap.

Thanks for the pointers, I was able to solve the problem. Actually inside the WMI Provider I was not cloaking the call to next call of WMI. I did this and it works perfectly fine:

     hr = CoSetProxyBlanket(WbemServices, RPC_C_AUTHN_WINNT, RPC_C_AUTHZ_DEFAULT ,
                                    NULL, RPC_C_AUTHN_LEVEL_DEFAULT,
               RPC_C_IMP_LEVEL_IMPERSONATE, NULL, EOAC_DYNAMIC_CLOAKING);

The last parameter I set as EOAC_DYNAMIC_CLOAKING.