Re: XForms: Bad file number messages

From: Steve Lamont (
Date: Mon Apr 02 2001 - 09:43:17 EDT

  • Next message: zaphodb: "Re: XForms: Bad file number messages"

    # To subscribers of the xforms list from Steve Lamont <> :

    > When I'm running a libforms89 based app from a cygwin shell in the cygwin
    > shell I get loads and loads of repetitions of a specific message:
    > In select [asyn_io.c 170] Bad file number--Bad file number

    select() is getting fed a file descriptor that is not valid,

    What is the application?

    Is it using fl_add_io_callback()? Are you certain that the
    descriptors being fed to it are valid or have not been closed before
    being deleted from the watch queue by fl_remove_io_callback() -- doing
    this in the wrong order could cause some spurious messages.

    Can you reproduce the problem on some other system?

    Can you reproduce the problem with any of the demos?

    Can you provide test code?

    > Printing these messages to the screen alone to me seems to consume
    > quite a bit of processing power. Does anybody know what is causing
    > this and how this can be helped? According to cygwin and xfree
    > connaisseurs this is not a cygwin or X-server problem. So the
    > message must stem from the xforms library.

    Well, yes, it does come from the library in the sense that it is
    produced by the routine which handles the select() function call
    monitoring the file descriptor but the cause is more likely to be
    external to the library unless one of the internal data structures has
    become corrupt.

    > ... What do they mean ...

    See above.

    > ... and can
    > I prevent these messages from being printed thus preserving the
    > processing power for the app.?

    Either do your own error handling by calling fl_set_error_handler() to
    the change the error handling or fix the app.


    To unsubscribe, send the message "unsubscribe" to or see
    XForms Home Page:
    List Archive:

    This archive was generated by hypermail 2b29 : Mon Apr 02 2001 - 04:45:36 EDT