Results 1 to 4 of 4

Thread: Stranger Error

  1. #1
    Join Date
    May 2006
    Posts
    57
    Thanks
    12
    Qt products
    Qt4
    Platforms
    MacOS X Unix/X11 Windows

    Question Stranger Error

    In my program draw a path and this path is changing continuously(in a thread), but suddenly appear this error in GDB:

    Program received signal SIGSEGV, Segmentation fault.
    [Switching to Thread 0xb5fffb90 (LWP 8229)]
    0xb78b60f1 in QRegionPrivate::append (this=0xb6002e48, r=0xb60086f8)
    at ../../include/QtCore/../../src/corelib/tools/qrect.h:245
    245 { return y1; }
    Current language: auto; currently c++

    What could be?
    Last edited by avis_phoenix; 8th September 2008 at 22:53. Reason: Spelling error

  2. #2
    Join Date
    Jan 2006
    Location
    Warsaw, Poland
    Posts
    5,372
    Thanks
    28
    Thanked 975 Times in 912 Posts
    Qt products
    Qt3 Qt4
    Platforms
    Unix/X11 Windows

    Default Re: Stranger Error

    What synchronization mechanism do you use and does this thread do exactly?

  3. #3
    Join Date
    May 2006
    Posts
    57
    Thanks
    12
    Qt products
    Qt4
    Platforms
    MacOS X Unix/X11 Windows

    Default Re: Stranger Error

    The thread (is a QThread) calculate the path, in the main thread (in the interface) draw the path .

    I use connect (direct connect) to singals for draw.

  4. #4
    Join Date
    Jan 2006
    Location
    Warsaw, Poland
    Posts
    5,372
    Thanks
    28
    Thanked 975 Times in 912 Posts
    Qt products
    Qt3 Qt4
    Platforms
    Unix/X11 Windows

    Default Re: Stranger Error

    Quote Originally Posted by avis_phoenix View Post
    I use connect (direct connect) to singals for draw.
    If you use a direct signal, then the drawing is also done in that non-GUI thread, which is Bad(tm).

    Use a queued connection to send an updated path to the GUI thread or use a mutex to protect the path while you draw it.

Similar Threads

  1. Compile 4.4.0
    By LordQt in forum Installation and Deployment
    Replies: 18
    Last Post: 29th May 2008, 13:43
  2. QPSQL driver in windows
    By brevleq in forum Installation and Deployment
    Replies: 31
    Last Post: 14th December 2007, 12:57
  3. Error compiling psql plugin
    By vieraci in forum Installation and Deployment
    Replies: 4
    Last Post: 7th October 2007, 02:49
  4. qt 4.2.2 install on aix
    By try to remember in forum Installation and Deployment
    Replies: 2
    Last Post: 28th March 2007, 12:19
  5. use qpsql
    By raphaelf in forum Installation and Deployment
    Replies: 34
    Last Post: 22nd August 2006, 12:52

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Digia, Qt and their respective logos are trademarks of Digia Plc in Finland and/or other countries worldwide.