I am hosting the web browser control in my own window. Here are the pertinent steps:
CoGetClassObject(CLSID_WebBrowser,
CLSCTX_INPROC_SERVER | CLSCTX_INPROC_HANDLER,
NULL, IID_IClassFactory, (void **)&pClassFactory);
pClassFactory->CreateInstance(0, IID_IOleObject, (void **)&pObject);
pClassFactory->Release();
pObject->SetClientSite((IOleClientSite *)impl)
OleSetContainedObject((struct IUnknown *)pObject, true)
pObject->DoVerb(OLEIVERB_SHOW, NULL, (IOleClientSite *)impl, 0, hHpsWnd, &rect);
pWB->put_Visible(VARIANT_FALSE);
hr=pWB->Quit();
At the last statement above the hr return value is E_FAIL. The end result of this failure in my code is leaking of a bunch of resources. What am I doing incorrectly?
Reading the documenation here it states the WebBrowser object (i.e. CLSID_WebBrowser) returns an error from the Quit method because it does not make sense in context. The Quit method will quit the out of process version of IE which also uses the same interface to communicate.
Only thing I can suggest is double check you are releasing all COM object relating to the browser.
Related
Where does the verifier print its messages? I have a simple code embedded in struct bpf_insn which I load and attach as BPF_PROG_TYPE_SOCKET_FILTER type:
struct bpf_insn prog[] = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
BPF_EXIT_INSN(),
};
This code is intentionally made wrong (R0 is not initialized before the exit). bpf_prog_load() returns EACCESS error and fails to load, which is expected, but I wanted to the verifier messages (nothing in dmesg or console).
When attempting to load an eBPF program, it is up to the loader to pass a buffer to the kernel verifier and to later print it to get the verifier's output.
The verifier will use this buffer provided by the user space program and print all its logs in it. Excepted for a very few specific messages, it will not print anything to the kernel logs or to the console (which is handled by your shell, not the kernel directly).
Let's have a look at a snippet from samples/bpf/sock_example.c, that you mentioned in the comments.
prog_fd = bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER, prog, insns_cnt,
"GPL", 0, bpf_log_buf, BPF_LOG_BUF_SIZE);
if (prog_fd < 0) {
printf("failed to load prog '%s'\n", strerror(errno));
goto cleanup;
}
This is the part where we attempt to load the program. We call bpf_load_program() from libbpf, and we pass it, in this order, the program type, the instructions, the number of instructions, the license string, some flag related to kernel versions, and at last: an empty buffer and its size. The size BPF_LOG_BUF_SIZE is non-null (defined in tools/lib/bpf/bpf as (UINT32_MAX >> 8)).
The function bpf_load_program() will pass all this information, including the pointer to the buffer, to the bpf() system call, which will attempt to load the program. The verifier will populate the buffer with logs (whether the load succeeds or not, but see note at the bottom). Then it is up to the loader program, again, to use these logs. The function bpf_load_program() is low-level, it does nothing with the verifier's logs in the buffer, even on failure to load. It leaves it to the caller to process or dump the logs. The sample application that you attempt to run does nothing either; therefore, the buffer is unused, and you don't get to see the logs in the console.
To see the logs, in your case, you probably just need to dump this buffer. Something as simple as the following should work:
...
if (prog_fd < 0) {
printf("failed to load prog '%s'\n", strerror(errno));
printf("%s", bpf_log_buf);
goto cleanup;
}
Note: In addition to the buffer and the size of the buffer, the loader must pass a log_level integer to the verifier, to tell it what level of verbosity it should use. If the value is at 0, the verifier prints nothing to the buffer. In the current case, we do not handle the log_level directly. bpf_load_program() does not either and sets the value to 0, but it ends up calling libbpf__bpf_prog_load() in libbpf. That function tries to load the program a first time without changing the log_level, but in case of failure, it does a new attempt with the log_level set at 1 - See Mark's pointers in the comments for details. The different values for log_level are defined in internal kernel headers and are not part of the user API, meaning the behaviour of the verifier regarding log verbosity may vary between kernel versions.
I have tested two cases:
I use STEPCAFControl_Reader then STEPControl_Reader to read my step file but both methods crash when I call STEPCAFControl_Reader::Transfer, repsectively STEPControl_Reader:: TransferRoots.
By using STEPControl_Reader, I displayed a log on my console, then there is a message like this:
1 F:(BOUNDED_SURFACE,B_SPLINE_SURFACE,B_SPLINE_SURFACE_WITH_KNOTS,GEOMETRIC_REPRESENTATION_ITEM,RATIONAL_B_SPLINE_SURFACE,REPRESENTATION_ITEM,SURFACE): Count of Parameters is not 1 for representation_item
EDIT:
There is a null reference inside TransferRoots() method.
const Handle(Transfer_TransientProcess) &proc = thesession->TransferReader()->TransientProcess();
if (proc->GetProgress().IsNull())
{
//This condition does not exist from the source code
std::cout << "GetProgress is null" << std::endl;
return 0;
}
Message_ProgressSentry PS ( proc->GetProgress(), "Root", 0, nb, 1 );
My app and FreeCAD crash but if I use CAD Assitant which OCC official viewer, it loads.
It looks like comments already provide an answer to the question - or more precisely answers:
STEPCAFControl_Reader::ReadFile() returns reading status, which should be checked before calling STEPCAFControl_Reader::Transfer().
Normally, it is a good practice to put OCCT algorithm into try/catch block and check for OCCT exceptions (Standard_Failure).
Add OCC_CATCH_SIGNALS at the beginning of try statements (required only on Linux) and OSD::SetSignal(false) within working thread creation to redirect abnormal cases (access violation, NULL dereference and others) to C++ exceptions (OSD_Signal which is subclass of Standard_Failure). This may conflict other signal handlers in mixed environment - so check also documentation of other frameworks used by application.
If you catch failures like NULL dereference on calling OCCT algorithm with valid arguments - this is a bug in OCCT which is desirable to be fixed in one or another way, even if input STEP file contains syntax/logical errors triggering such kind of issues. Report the issue on OCCT Bugtracker with sufficient information for reproducing bug, including sample files - it is not helpful to developers just saying that OCCT crashes somewhere. Consider also contributing into this open source project by debugging OCCT code and suggesting patches.
Check STEP file reading log for possible errors in the file itself. Consider reporting an issue to system producing a broken file, even if main file content can be loaded by STEP readers.
It is a common practice to use OSD::SetSignal() within OCCT-based applications (like CAD Assistant) to improve their robustness on non-fatal errors in application/OCCT code. It is more user friendly reporting an internal error message instead of silently crashing.
But it should be noted, that OSD::SetSignal() doesn't guarantee application not being crashed nor that application can work properly after catching such failure - due to asynchronous nature of some signals, the memory can be already corrupted at the moment, when C++ exception has been raised leading to all kinds of undesired behavior. For that reason, it is better not ignoring such kind of exceptions, even if it looks like application works fine with them.
OSD::SetSignal(false); // should be called ones at application startup
STEPCAFControl_Reader aReader;
try
{
OCC_CATCH_SIGNALS // necessary for redirecting signals on Linux
if (aReader.ReadFile (theFilePath) != IFSelect_RetDone) { return false; }
if (!aReader.Transfer (myXdeDoc)) { return false; }
}
catch (Standard_Failure const& theFailure)
{
std::cerr << "STEP import failed: " << theFailure.GetMessageString() << "\n";
return false;
}
return true;
In the empty project after you open TFDConnection->Open() the connection to Mongodb upon completion of the program crashes error 'Bluetooth: unable to clean up Winsock'.
This error appears to occur during the TWinBluetoothSocket.Destroy routine in System.Win.Bluetooth. For some reason, the TWinBluetoothSocket destructor is called in a C++ application, even though Bluetooth is not used.
The problem is that WSACleanup() is being called by the TWinBluetoothSocket destructor, but WSAStartup() had never been called, so WSACleanup() returns an error.
This occurs when the Mongo driver is used in a C++ application, even when the TFDConnection is in a Delphi unit, as long as the Mongo driver is selected and Connected is set to true in design or runtime.
No MongoDB server is needed to reproduce this; just set Connected to be true in a button click handler. Of course, an error will occur because there is no MongoDB server, but this error will occur when the application exits.
The workaround is to put this in the Constructor (from https://msdn.microsoft.com/en-us/library/windows/desktop/ms742213(v=vs.85).aspx)
WORD wVersionRequested;
WSADATA wsaData;
int err;
/* Use the MAKEWORD(lowbyte, highbyte) macro declared in Windef.h */
wVersionRequested = MAKEWORD(2, 2);
err = WSAStartup(wVersionRequested, &wsaData);
if (err != 0)
{
ShowMessage("err nonzero");
}
Now, WSAStartup() is called, so WSACleanup() does not return an error, and the application can close.
OK, I have been at this for a while ...
I am trying to track when user changes input languages from Language Bar.
I have a Text Service DLL - modeled from MSDN and WinSDK samples - that registers fine, and I can use the interfaces ITfActiveLanguageProfileNotifySink & ITfLanguageProfileNotifySink and see those events just fine.
I also have finally realized that when I change languages these events occur for the application/process that currently has focus.
What I need to do is to simply have these events able to callback to my own application, when it has the focus. I know I am missing something.
Any help here is appreciated.
Thanks.
I did some double-checking, and you should be able to create a thread manager object without implementing ITextStoreACP so long as you don't call ITfThreadMgr::Activate.
So, the code should look like:
HRESULT hr = CoInitialize(NULL);
if (SUCCEEDED(hr))
{
ITfThreadMgr* pThreadMgr(NULL);
hr = CoCreateInstance(CLSID_TF_ThreadMgr, NULL, CLSCTX_INPROC_SERVER, IID_ITfThreadMgr, (LPVOID*) &pThreadMgr);
if (SUCCEEDED(hr))
{
ITfSource *pSource;
hr = pThreadMgr->QueryInterface(IID_ITfSource, (LPVOID*)&pSource);
if(SUCCEEDED(hr))
{
hr = pSource->AdviseSink(IID_ITfActiveLanguageProfileNotifySink,
(ITfActiveLanguageProfileNotifySink*)this,
&m_dwCookie);
pSource->Release();
}
}
}
Alternatively, you can use ITfLanguageProfileNotifySink - this interface is driven from the ItfInputProcessorProfiles object instead of ItfThreadMgr. There's a sample of how to set it up on the MSDN page for ItfLanguageProfileNotifySink.
For both objects, you need to keep the source object (ITfThreadMgr or ITfInputProcessorProfiles) as well as the sink object (what you implement) alive until your application exits.
Before your application exits, you need to remove the sink from the source object using ITfSource::UnadviseSink, and then release the source object (using Release). (You don't need to keep the ItfSource interface alive for the life of your application, though.)
I'm writing an application that can be started either as a standard WinForms app or in unattended mode from the command-line. The application was built using the VS 2k5 standard WinForms template.
When the application is executed from the command-line, I want it to output information that can be captured by the script executing the application. When I do this directly from Console.WriteLine(), the output does not appear, although it can be captured by piping to a file.
On the other hand, I can force the application to pop up a second console by doing a P/Invoke on AllocConsole() from kernel32. This is not what I want, though. I want the output to appear in the same window the application was called from.
This is the salient code that allows me to pop up a console from the command line:
<STAThread()> Public Shared Sub Main()
If My.Application.CommandLineArgs.Count = 0 Then
Dim frm As New ISECMMParamUtilForm()
frm.ShowDialog()
Else
Try
ConsoleControl.AllocConsole()
Dim exMan As New UnattendedExecutionManager(ConvertArgs())
IsInConsoleMode = True
OutputMessage("Application started.")
If Not exMan.SetSettings() Then
OutputMessage("Execution failed.")
End If
Catch ex As Exception
Console.WriteLine(ex.ToString())
Finally
ConsoleControl.FreeConsole()
End Try
End If
End Sub
Public Shared Sub OutputMessage(ByVal msg As String, Optional ByVal isError As Boolean = False)
Trace.WriteLine(msg)
If IsInConsoleMode Then
Console.WriteLine(msg)
End If
If isError Then
EventLog.WriteEntry("ISE CMM Param Util", msg, EventLogEntryType.Error)
Else
EventLog.WriteEntry("ISE CMM Param Util", msg, EventLogEntryType.Information)
End If
End Sub
Raymond Chen recently posted (a month after the question was posted here on SO) a short article about this:
How do I write a program that can be run either as a console or a GUI application?
You can't, but you can try to fake it.
Each PE application contains a field
in its header that specifies which
subsystem it was designed to run
under. You can say
IMAGE_SUBSYSTEM_WINDOWS_GUI to mark
yourself as a Windows GUI application,
or you can say
IMAGE_SUBSYSTEM_WINDOWS_CUI to say
that you are a console application. If
you are GUI application, then the
program will run without a console.
The subsystem determines how the
kernel prepares the execution
environment for the program. If the
program is marked as running in the
console subsystem, then the kernel
will connect the program's console to
the console of its parent, creating a
new console if the parent doesn't have
a console. (This is an incomplete
description, but the details aren't
relevant to the discussion.) On the
other hand, if the program is marked
as running as a GUI application, then
the kernel will run the program
without any console at all.
In that article he points to another by Junfeng Zhang that discusses how a couple of programs (Visual Studio and ildasm) implement this behavior:
How to make an application as both GUI and Console application?
In VisualStudio case, there are actually two binaries: devenv.com and devenv.exe. Devenv.com is a Console app. Devenv.exe is a GUI app. When you type devenv, because of the Win32 probing rule, devenv.com is executed. If there is no input, devenv.com launches devenv.exe, and exits itself. If there are inputs, devenv.com handles them as normal Console app.
In ildasm case, there is only one binary: ildasm.exe. It is first compiled as a GUI application. Later editbin.exe is used to mark it as console subsystem. In its main method it determines if it needs to be run as console mode or GUI mode. If need to run as GUI mode, it relaunches itself as a GUI app.
In the comments to Raymond Chen's article, laonianren has this to add to Junfeng Zhang's brief description of how Visual Studio works:
devenv.com is a general purpose console-mode stub application. When it runs it creates three pipes to redirect the console's stdin, stdout and stderr. It then finds its own name (usually devenv.com), replaces the ".com" with ".exe" and launches the new app (i.e. devenv.exe) using the read end of the stdin pipe and the write ends of the stdout and stderr pipes as the standard handles. Then it just sits and waits for devenv.exe to exit and copies data between the console and the pipes.
Thus even though devenv.exe is a gui app it can read and write the "parent" console using its standard handles.
And you could use devenv.com yourself for myapp.exe by renaming it to myapp.com. But you can't in practise because it belongs to MS.
Update 1:
As said in Michael Burr answer, Raymond Chen recently posted a short article about this. I am happy to see that my guess was not totally wrong.
Update 0:
Disclaimer: This "answer" is mostly speculation. I post it only because enough time has passed to establish that not many people have the answer to what look like a fundamental question.
I think that the "decision" if the application is gui or console is made at compile time and not at runtime. So if you compile your application as gui application, even if you don't display the gui, its still a gui application and doesn't have console. If you choose to compile it as console application then at minimum you will have a console windows flashing before moving to gui "mode". And I don't know if it is possible in managed code.
The problem is fundamental, I think, Because a console application has to take "control" of the calling console application. And it has to do so before the code of the child application is running.
If you want to check if your app is started from the command line in .NET, you can use Console.GetCursorPosition().
The reason that this works is that when you start it from the command line, the cursor moves away from the initial point ((0, 0)) because you typed something in the terminal (the name of the app).
You can do this with an equality check (code in C#):
class Program
{
public static void Main
{
if (Console.GetCursorPosition() == (0, 0))
{
//something GUI
}
else
{
//something not GUI
}
}
}
Note: You must set the output type to Console Application as other output types will make Console.GetCursorPosition() throw an exception.