Can't open default greio channel


I have a program. It works on one computer correctly, but it work with mistake on the other. I use OS QNX6.5.0. Running so:
export GRE_PLUGINS=/home/qnx-6_5-x86-sdl-obj/plugins
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/qnx-6_5-x86-sdl-obj/lib
ldd /home/qnx-6_5-x86-sdl-obj/plugins/
/home/sbengine -ogreio,channel=my_channel /home/MyTest.gapp >> /home/testCrank.txt

In file testCrank.txt i get a mistake: "Can't open default greio channel". Program use functions: gre.send_event, gre.send_event_data and etc.
I understand, that you need to say more about your program and find the line of code in which this error appears.
But, maybe, you have an idea, how correct mistake. Maybe load a library or run an auxiliary process. Maybe I run my program wrong.

Have you an idea, how I correct the mistake in the program?



  • Hello Yven,

    It's difficult to tell exactly what the problem is without having a little bit more context. Storyboard IO on QNX depends on mqueue so if that service isn't running then you won't be able to send messages. After you verify that there are a few things that you can check/try.

    The first would be to verify that the channels in the UI and backend application match. Secondly, is there a dependency in the order in which your UI and back need to start i.e: does the UI need to be running before the backend can send messages? If those two options appear to be correct then you can try validating Storyboard IO by using the iogen and iorcv command line utilities to see if the protocol is functioning properly. You can find these utilities in the bin directory of your runtime folder.

    Here is a link to the docs for iogen/iorcv, I'm unsure of your Storyboard version so be sure to check your documentation as the usage options have changed around version 5.0

    If those utilities work then you can be sure there is something going on in your application logic that should be easy enough to track down. If you continue to have problems can you let me know what version of Storyboard you are using?

  • Can you give a link where I can read about the channels in the UI and the backend application match?

  • Hello Yven,

    Here is a link (Storyboard 5.3) which talks about using Storyboard IO. You will need to make sure that the channel the UI is listening on, in your case "my_channel" is what is used in your backend application code.

    The same information can be found in pdf format in your installation directory under the Documentation folder. Referencing the documentation that matches your version of Storyboard will ensure that you have the most accurate information for your scenario.

    Thank you


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