I have a strange problem - after my C++ application runs for 39 hours on Windows XP, the network is broken and the application fails. Seen that several times. When I try to "ping localhost", the prompt says "no resources". I found this thread in Internet, where people advice to make "ipconfig /renew".
The thing is I just want to know, what actions (Windows API calls) causes that. I'm nearly 100% sure that the problem is in the network card (because the other card works well), but I just want to understand, what my actions cause that.
Unforunately, my application consists of megabytes of code, so I can't just uncomment a few lines to see if I can reproduce error now.
Is there any list of Windows API calls that are executed by network card driver? For instance, "sendto" is most likely executed by driver, because it sends data to network.
Is there any test (like Acid test for browsers), which can show if network driver does not behave correctly?
It kind of sounds like you've run out of sockets. Are you sure you're freeing the sockets once you've used them?
Make sure that your network card is updated with latest driver or re install the driver and then restart the machine once.
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I feel like this should be rather easy, but it continues to vex me, so here it is. I've been trying to find a simple solution to iterate through the available UART serial ports on linux (I'm running the most recent version of Manjaro Linux) and then printing these to the console. Yet, all of the solutions I've found thus far have been incredibly convoluted or they end up throwing a bunch of errors that I can'at figure out when I test them.
So, I've resorted to coming back here to see if anybody else has any ideas. On Windows, there is a GetPortNames() of Windows' System::IO::Ports, maybe a similar API call would be the most ideal.
Update:
So after receiving an answer and using that information to learn a bit more about interacting with serial ports on linux, I eventually ran across a good way to accomplish this effect of iterating through the available ports. It's not quite as simple as a one-line command, but it works so it's fine with me. I found this method of iteration/sorting through the /sys/class/tty directory as an answer to another question (the author of the code that I used is named Søren Holm), and you can look at that here.
Two simple possibilities:
Serial ports on linux are character device files, you can see them on /dev/ttyS*. Serial ports created by an usb device are in /dev/ttyUSB*. This reduces your problem to a dirent iteration.
There is also a thing named sysfs, it is essentially a runtime, non-persistant, kernel-internal registry which is exported to the user space via a virtual filesystem. Normally it is mounted below /sys. Below /sys/bus/serio/devices you can find the devices.
I am working on a C++-based MIDI sending app and it's the first time I'm working with MIDI.
I chose the RtMidi library because it seems to be the most complete library around, but I'm open to suggestions.
The OS that I'm working on is Windows 7 and I have an USB-MID interface installed and it's working with other programs (i.e. Roland UM-One).
Now I may be way off-track, but I'd expect that when you do a search for ports, it should show this device.
When compiling the example code for RtMidi i get no ports; in or out.
What am I missing?
Do i need to open a virtual port?
This is also for others experiencing a similar issue as well:-
When I first started using RtMIDI, if you don't specify (on OSX at least) a macro define for the target system, the example code by default uses a dummy MIDI device, and this will have no MIDI ports.
Once I had specified MAC_OSX_CORE, then RtMIDI used the correct architecture and returned the MIDI devices on my system as expected. Perhaps you have to do something similar for your system - check the docs under "Compiling":
http://www.music.mcgill.ca/~gary/rtmidi/index.html#compiling
I've worked briefly with RtMidi and it is, as you stated, a rather complete library. However, when working with MIDI devices, you have to take the specific issues of this type of devices into account.
Another thing is that cheap USB-MIDI adapters often simply refuse to work with some applications "just because". They are very simple inside, yet apparently chinese manufacturers are still able to make malfunctioning devices.
If you're using unmodified, example code, and it's not showing your device, I'll first ensure all other apps that might be using it are closed, then try again. Creating a virtual interface is also a nice idea; I personally use freeware LoopBe1 for it. If it will show the virtual, but not the real interface, then the problem is with device itself. In that case you might want to experiment with different drivers or simply plugging it into a different port.
If it doesn't show any device, neither real nor virtual, then I strongly suspect there's something wrong in the way you build/run the application.
There is a multithreaded program that operates simultaneously with a device via COM port based communication and remote (IP) video stream. The program also uses OpenCV library to process the data.
The trouble is that it shuts down without any signals (neither run-time, nor any other errors are caught; log file has no anything useful as well). The most top level application error event handler is set and still there are no any signs of the program crash. It just closes after awhile.
The biggest difficulty is that it works fine on all our PCs for days non-stop. But fails on customers PCs so that testing process is very slow. Customer is in a different country (Asian localization, whilst ours is European), but the program is built with Unicode support.
So far we have got some assumptions about localization issues and antivirus activity... but it gives nothing in result.
The program is written with MinGW 4.4.x C++ and wxWidgets 2.9.3
Any suggestions of the probable origin would be appreciate.
Solved.
The problem was inside OpenCV build 2.3.1, that we use. The function cv::imdecode(...) uses stdio.h`s tempnam() function to generate temporary file during decoding. Under x86 Windows systems this function fails after 32767 new names for temporary file. Under x64 Windows systems it returns some nonsense string, but it still works.
So the solution I came with was to change the way of receiving-decoding images from our device.
Thanks everybody for comments.
i need to find away to turn on the pc from c++ application ,
is there any way to do this?
Thanks
If the computer is off, it can't be executing code, and therefore can't turn itself on programmatically.
ACPI changes that somewhat, but for us to be able to help, you have to be more specific about your exact requirements.
If you need to turn on a different computer, take a look at Wake-on-LAN.
You will not be able to write a program to turn a computer on that the program itself is installed on.
If you need to write an application that will turn on a different computer, Wake-on-LAN is the tool for you. Modern desktops have NICs that is always receiving power - even if the computer is in an S5 state. Assuming the BIOS supports it and it is enabled.
Wake-On-LAN works by sending a Magic Packet to the NIC. The details of what the payload consists of is outlined in the article.
This is possibly a duplicate of C#: How to wake up system which has been shutdown? (although that is C#).
One way to do it under windows is to create a timer with CreateWaitableTimer(), set the time with SetWaitableTimer() and then do a WaitForSingleObject(). Your code will pause, and you can put the computer into standby (maybe also hibernation, but not shutdown). When the timer is reached, the PC will resume and so will your program.
See here for a complete example in C. The example shows how to calculate the time difference for the timer, and how to do the waiting in a thread (if you are writing a graphical application).
I have to add, you can also schedule the computer to wake up using the Windows Task Scheduler ('Wake the computer to run this task'). This possibly also works when the computer is shut down. There is also an option in some computers BIOS to set a wake time.
Under Linux, you can set the computer to wake up by writing to a special file:
echo 2006-02-09 23:05:00 > /proc/acpi/alarm
Note that I haven't tested all of this, and it is highly dependent on the hardware (mainboard), but some kind of wake-up should be available on all modern PCs.
See also: http://en.wikipedia.org/wiki/Real-time_clock_alarm ,
and here is a program that claims to do it on windows: http://www.dennisbabkin.com/wosb/
Use strip. If you require a Windows computer to be turned on, the cross-tools i686-w64-mingw32-strip or x86_64-w64-mingw32-strip should be used. These command-line programs modify an executable, and the result is able to turn on a computer.
How could you turn on a computer from an application, when no processes are running on it when it's shut down ? You can turn on another computer (Wake on Lan), but not the one you are running.
It is possible.
First thing to do is configure Wake On Lan. Check out this post on Lifehacker on how to do it: http://lifehacker.com/348197/access-your-computer-anytime-and-save-energy-with-wake+on+lan.
(Or this link: http://hblg.info/2011/08/21/Wake-on-LAN-and-remote-login.html)
Then you need to send a magic packet from your C++ application. There are several web services that already do this from javascript (wakeonlan.me) , but it can be done from within a C++ application as well.
Chances are, that if you want to do this, you are working with servers.
In such case, your mainboard may should an IMPI baseboard management controller.
IPMI may be used to cycle the chassis power remotely.
Generally, the BMC will have its own IP address, to which you may connect to send control messages.
I've written an Windows Server which uses the WMI feature of Windows to monitor system health. For that purpose, a WMI connection is opened, queried and closed every thirty seconds. That works quite well on Windows Server 2008 (R2).
On the other side, I have a couple of Servers running Windows Server 2003 x64, which run constantly into BSODs when using my Service (and only when using my Service). The Error code is commonly 0x9c, sometimes 0x19. Others told me that system memory may be corrupted, but it's very unlikely since all 2003-x64-based servers are experiencing that problems.
The Windows error log lists three error messages of type "WDMxWMI", without any further details, before the system reboots because of an bluescreen.
I don't know why this happens, and I neither know if, or how my program could be the reason for that, since I'm using the WMI exacly like the MSDN examples told me. Last but not least, it works absolutely fine on 2008-based servers.
I'll be thankful for any advice.
A bugcheck of this nature seems to indicate a serious hardware problem.
http://support.microsoft.com/?kbid=329284
https://serverfault.com/questions/7060/troubleshooting-the-dreaded-0x9c-bsod