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CloseHandle(....) causing crash

My call to CloseHandle(...) causes my program to crash. I tried putting the call inside a try/catch, so that I could display a message box in the event of a problem with this call. However, my program still crashes. The handle argument that I'm passing to CloseHandle(...) seems to be ok. Does anyone know some good exception handling for CloseHandle(....)????

Axter

I recommend you initialize your handle value to NULL or INVALID_HANDLE_VALUE.

Then when ever you call CloseHandle, set the handle to INVALID_HANDLE_VALUE after making the call.

You can easily make a wrapper function for this that will reset your handle automatically after each call to CloseHandle.

grg99

check over your code to make sure the handle has been opened and hasnt been closed elsewhere. The code should look very much like:

HANDLE H;

H = 0;

H = whateverAPIreturnsafile_socket_pipe_process_or_graphics_handle( foo, goo, zoo );

if( H != BADHANDLE ) {
dosoemthingswith( H );
if( H == 0 ) printgf( "OOPS, Handle already closed!!! how did we do this twice?" );
else {
Err = CloseHandle( H );
if( Err != BAD ) printf("oops on handle" );
H = 0;
}
}

Axter

You can try using __try / __except to catch the error.

Axter

Be aware, that a NULL return value is valid for some API functions, and that not all API functions return NULL or INVALID_HANDLE_VALUE for an error condition.

You need to read the API function documentation to determine what is consider an error (non-initialized) value.

grg99

um, catching the error is usually regarded as a KLOOODGE.
Sort of like taking aspirin before going down the alley where you're sure to be mugged over the head.
Maybe better to not go down the alley.....

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jkr

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Axter

I believe that should be the following:
GetHandleInformation(hMyHandle, &dwFlags);

Deepu Abraham

According to MSDN:
If the application is running under a debugger, the function will throw an exception if it receives either a handle value that is not valid or a pseudo-handle value. This can happen if you close a handle twice, or if you call CloseHandle on a handle returned by the FindFirstFile function.

More details:
http://msdn2.microsoft.com/en-us/library/ms724211.aspx

Hope this will help you troubleshoot.
Best Regards,
DeepuAbrahamK