C / C++ / MFC Discussion Boards

CreateFile, ReadFile and Writhe file thread

Bogdan Markovic29-Aug-11 3:28

29-Aug-11 3:28

Hello to everybody,
I wrote a simple code for data reading and writing from USB HID device.
My code looks as follows:

HidDeviceObject = CreateFile (
        (LPCTSTR)DevicePath,
        GENERIC_READ | GENERIC_WRITE,
        FILE_SHARE_READ | FILE_SHARE_WRITE,
        (LPSECURITY_ATTRIBUTES)NULL,
        OPEN_EXISTING,  
        0, 
        NULL);

In this way I open device for communication (synchronously).
Now I create two threads, one for data reading and one for data writing to device.
This is read thread:

while(TRUE)
{
  if(!WRITE_BUTTON)
  {
    if (HidDeviceObject != INVALID_HANDLE_VALUE)
	{
	  CancelIo(HidDeviceObject);
	  int Result = ReadFile(HidDeviceObject, &InputReport, sizeof(InputReport), & NumberOfBytesRead,NULL);
	}
   }
}

where WRITE_BUTTON is flag( if I click on write button in my GUI, WRITE_BUTTON is equal to 1, else 0)
My write thread is:

while(TRUE)
{
    if(WRITE_BUTTON)
    {
        if (HidDeviceObject != INVALID_HANDLE_VALUE)
        {
            CancelIo(HidDeviceObject);
            int Result = WriteFile(HidDeviceObject,&OutputReport, sizeof(OutputReport), & NumberOfBytesWriten, NULL);
            WRITE_ROPRT = FALSE;
        }
    }

I am new in thread programing, and I need help fast. If I comment one of the threads, second one works fine. Where is my mistake? How to make them to works together in the same time? I want to send some data to device and wait for device to respond to me. When I open device with async flag (asynchronously) ( instead 0 in CreateFile function, I put FILE_FLAG_OVERLAPPED) threads works fine together, and I can send data to device and "capture" response from it.
Thanks

Re: CreateFile, ReadFile and Writhe file thread

Malli_S29-Aug-11 4:10

Malli_S

29-Aug-11 4:10

Thread Synchronization for Beginners[^]

Introduction to Multi-threaded Code[^]

[Delegates] [Virtual Desktop] [Tray Me !]

-Malli...!

Porting MFC Application [modified]

pix_programmer28-Aug-11 23:06

pix_programmer

28-Aug-11 23:06

Hi!
I've developed a dialog based MFC application which embeds flash movie(.swf files) in it. Some more things I've used in this application are:

(i) CInternetSession
(ii)IXMLHTTPRequestPtr

I've to port this application to Linux and Mac. Is it possible? If yes, what tool is needed(Of course, it should be free)? Will Linux and Mac support .OCX(Activex) components?

modified on Monday, August 29, 2011 5:12 AM

Re: Porting MFC Application

Sarath C28-Aug-11 23:51

Sarath C

28-Aug-11 23:51

There's an excellent article in IBM website [^] to port MFC Applications to Linux using wxWidgets[^]

-Sarath.

My blog - Sharing My Thoughts

Rate the answers and close your posts if it's answered

Re: Porting MFC Application

pix_programmer29-Aug-11 0:20

pix_programmer

29-Aug-11 0:20

Do I need to install any specific library to port my application? Or changing the class and Event names as told is enough?

Re: Porting MFC Application

Albert Holguin29-Aug-11 5:02

Albert Holguin

29-Aug-11 5:02

wxWidgets is a library (just like MFC is)... it needs to be installed to be used...

Re: Porting MFC Application

Rolf Kristensen29-Aug-11 8:53

Rolf Kristensen

29-Aug-11 8:53

Consider to use Qt if wanting to implement a cross platform native application.

Another alternative is to use Silverlight and .NET.

Re: Porting MFC Application [modified]

pix_programmer29-Aug-11 18:25

pix_programmer

29-Aug-11 18:25

Hi!
Is it available free? Won't there be any license issues? Can you please confirm these things before I decide to use Qt? If it's payable, how much is the cost?

modified on Tuesday, August 30, 2011 1:12 AM

Re: Porting MFC Application

Rolf Kristensen29-Aug-11 20:20

Rolf Kristensen

29-Aug-11 20:20

Qt is released under GNU Lesser General Public License (LGPL) version 2.1. Your application doesn't have to be open source to make use of it.

http://qt.nokia.com/products/licensing/[^]

Writing multiple files simultaneously inside the loop

VCProgrammer28-Aug-11 19:38

VCProgrammer

28-Aug-11 19:38

Hi all,

i want to write multiple files inside a loop simultaneously. But how many files will be written at a time will be decided at run time but, i know the maximum limit can be 15.

I am not getting how to create object of class FILE and then how to access them.

Can anybody help me in this.

Thanks in advance

Re: Writing multiple files simultaneously inside the loop

Sarath C28-Aug-11 23:53

Sarath C

28-Aug-11 23:53

Can this[^] and this[^] help you?

-Sarath.

My blog - codereflect.com

Rate the answers and close your posts if it's answered

Re: Writing multiple files simultaneously inside the loop

Code-o-mat28-Aug-11 23:58

Code-o-mat

28-Aug-11 23:58

Create using fopen[^]
Write using fwrite[^], fputs[^], fprintf[^] and alike.
Close by fclose[^].

The fopen page even has a small example around the bottom.

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> If it doesn't matter, it's antimatter.<

Re: Writing multiple files simultaneously inside the loop

Rolf Kristensen29-Aug-11 8:52

Rolf Kristensen

29-Aug-11 8:52

Usually it gives very bad performance to write to multiple files at the same time. Maybe this has changed with the introduction of SSD disks.

Code changes req. to improve 64 bit application performance

am 200928-Aug-11 18:22

am 2009

28-Aug-11 18:22

Hi ,

I am converting my 32 bit windows application in VC++ into 64 bit windows application. I convert it with configuration setting req. for 64 bit platform. But when i check performance of 64 bit application, it is same as 32 bit. I did not found any improvement is speed execution of application. What changes i need to do in C++ VC++ code to speed up the execution of my application on windows 64 bit OS.

Regards
abm

Re: Code changes req. to improve 64 bit application performance

Rolf Kristensen28-Aug-11 20:30

Rolf Kristensen

28-Aug-11 20:30

There is no performance improvement by converting to 64 bit, unless your application performs lots of 64 bit calculations.

The main reason for converting to 64 bit is to get access lots of RAM, so one is not restricted by the usual 1-2 GByte RAM. The minor reason is that in 10-15 years the 32 bit platform will no longer be supported (Like 16 bit was abandoned with Win7)

See also Find out if you need the 64-bit version of your product[^]

Re: Code changes req. to improve 64 bit application performance

MicroVirus29-Aug-11 1:33

MicroVirus

29-Aug-11 1:33

Just to add a little to the previous post:

There is a minor performance improvement for all programs in terms of function calls. The calling conventions have been optimised for speed, by passing the first few arguments via the CPU registries.

However, this increase is only seen if your application uses a lot of function calls. Mostly, the compiler tries to avoid them in the first place, such as using inlining.

Also, if you make lots of API calls then you should see a small increase, as the WoW64 subsystem is taken out between the application and the Windows kernel (which does the conversion to the new calling convention for the 32 bits applications).

But, mostly, 64 bits is for the increase in address space, the most noticeable example being that you can use more than 4 GiB of RAM in your system.

Manifest in resource script?

Groulien28-Aug-11 9:57

Groulien

28-Aug-11 9:57

I was messing around with resource files and such in C#.
I found out that with a Compiled Resource Script you can add multiple icons to your applications.
Then I found out that a manifest file allows you to force it to be run as admin.
But a choice has to be made between the two (in c#).

I came to the conclusion that the Compiled Resource Script must contain a manifest.(if this is faulty, please correct me.)
I took a quick look into Resource Scripts (RC) C++ and saw something of a structure.

IDI_ICON1 ICON "file.ico"
IDB_BITMAP1 BITMAP "file.bmp"

Taking a peek in the Resource.h file that was generated I noticed the definition for IDI_ICON1, same goes for IDB_BITMAP1. ICON and BITMAP seem keywords for the Resource Compiler (can't find their definitions in #includes).
But what if I want to add a manifest?
IDM_MAN MANIFEST "file.manifest"
ends up with a folder called "Manifest" (including quotes, which does not happen with ICON and BITMAP).
I've seen MSDN saying that a manifest can be to an existing (post-compile) binary file, but can it be done with Resource Script, compiled with RC.exe?

The first rule of CListCtrl is you do not talk about CListCtrl - kornman

Re: Manifest in resource script?

David Magnotti28-Aug-11 13:34

David Magnotti

28-Aug-11 13:34

If it's not a compiler bug, it could be possible the manifest data overwrites the resource information for icons. If that's the case, you might need to write a custom build step to manually add the manifest, or the icons.

I would imagine it's the manifest overwriting the other resources.

Re: Manifest in resource script?

David Crow29-Aug-11 4:26

David Crow

29-Aug-11 4:26

nbgangsta wrote:
But what if I want to add a manifest?
IDM_MAN MANIFEST
"file.manifest"
ends up with a folder called "Manifest" (including quotes,
which does not happen with ICON and BITMAP).

It usually ends up looking something like:

1    24    MOVEABLE PURE    "res\\MyApp.exe.manifest"

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"Some people are making such thorough preparation for rainy days that they aren't enjoying today's sunshine." - William Feather

Re: Manifest in resource script?

i007-Jan-13 14:20

i00

7-Jan-13 14:20

nbgangsta wrote:
But a choice has to be made between the two (in c#).

... not really...

You could (like me) use the icon resource in c sharp for the icon and then use something like:

If NativeMethod.IsProcessElevated = False Then
    'Elevate :)
    Dim proc As New ProcessStartInfo
    proc.UseShellExecute = True
    proc.WorkingDirectory = Environment.CurrentDirectory
    proc.FileName = Application.ExecutablePath
    proc.Verb = "runas"
    Using AppProcess As New Process
        AppProcess.StartInfo = proc
        Try
            AppProcess.Start()
        Catch ex As Exception
            'User probably closed
            Throw New Exception("UAC Authorization Failed")
        End Try
        AppProcess.WaitForExit()
    End Using
Else
    'Do Admin Stuff
End If

I run this in a Main method ... so your version may need to be modified ... Also I am more familiar with VB ... so have left you to convert it to c# Smile | :)

... Also you will need to download the Microsoft UAC project from here[^] for this to work Smile | :)

Kris

i00 Spell Check - No Third Party Components Required!

MDI child windows behaviuor like VC6 editor

_Flaviu26-Aug-11 23:03

_Flaviu

26-Aug-11 23:03

Have anybody know how to set an VC6 editor behaviuor on Ctrl+Tab at an standard MDI application ? A MDI application roll on window after window on Ctrl+Tab, if I release Ctrl key or not, but VC6 editor (and any other editor) show previuous child window if I release Ctrl key ... any ideas ? Thanks.

All window handle from point

Member 296547126-Aug-11 8:06

Member 2965471

26-Aug-11 8:06

hi, how can i get all the windows handle from a point?
For example if in (100,100) i have two windows overlapped, i want to get the handle of the topmost window and the handle of the other window.

Re: All window handle from point

Charles Oppermann26-Aug-11 10:24

Charles Oppermann

26-Aug-11 10:24

WindowFromPoint, ChildWindowFromPointEx.

For windows under windows, you'll have to EnumWindows and do your own hit testing.

/* Charles Oppermann */
http://weblogs.asp.net/chuckop

Re: All window handle from point

«_Superman_»27-Aug-11 13:45

«_Superman_»

27-Aug-11 13:45

Use EnumWindows to enumerate the windows.
Use GetWindowRect to get the rectangle of the window.
Then use PtInRect to check if the point of interest lies within the window rectangle.

«_Superman_»
I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

Polymorphism in C

Re: All window handle from point

Code-o-mat28-Aug-11 21:54

Code-o-mat

28-Aug-11 21:54

Additionally to what the others have said, the "get the rectangle and check if the point is inside it" method might not work with non-rectangular windows (layered windows with per-pixel alpha (see here[^]) or windows with a non-rectangular window region (see here[^]). I wonder if sending these kinds of windows the WM_NCHITTEST[^] message could tell you if the point is on the window or not.

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> If it doesn't matter, it's antimatter.<

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