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Thread: How to wait for events produced by non-Qt threads?

  1. #1
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    Question How to wait for events produced by non-Qt threads?

    I inherited qthread and in the run() I delared two HANDLEs and asked an outside library to fill them with event(s) then run some non-qt threads that ends by emitting these events.

    When I was using non-qt threads I can simply call waitformultipleobjects() to wait for the return of these outside threads, but now whenever I call waitformultipleobjects() the qthread crashes.

    Any idea why this happens? I suspect it's because QApplication converts the two events to QEvents, but how am I supposed to handle these kind of QEvents? Or can I declare QEvents and hand QEvents to the outside thread as HANDLEs?

  2. #2
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    Default Re: How to wait for events produced by non-Qt threads?

    Does this QThread inheirted thread do something besides waiting for those native events?
    Your biological and technological distinctiveness will be added to our own. Resistance is futile.

    Please ask Qt related questions on the forum and not using private messages or visitor messages.


  3. #3
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    Default Re: How to wait for events produced by non-Qt threads?

    nothing while waiting. actually I am using double buffer to receive pictures from a camera. Its sdk posts an event when a picture finishes to be sent to a buffer.
    the working loop is like this:
    Qt Code:
    1. for (int k = 0; k<8; k++)
    2. {
    3. //double buffer
    4. ready=WaitForMultipleObjects(2,hEvents,false,2000);
    5. if (ready==WAIT_OBJECT_0)
    6. {
    7. PCO_AddBufferEx(hCam,0,0,sBufNr1, xRes, yRes, 0x000e);
    8. for (int l = 0; l<xRes * yRes; l++)bitMap[l+mapOffset] = data1[l];
    9. Update();
    10. }
    11. else
    12. {
    13. if(ready==(WAIT_OBJECT_0+1))
    14. {
    15. PCO_AddBufferEx(hCam,0,0,sBufNr2, xRes, yRes, 0x000e);
    16. SetPort(false);
    17. for (int l = 0; l<xRes * yRes; l++)bitMap[l+mapOffset] = data2[l];
    18. Update();
    19. }
    20. else{
    21. PCO_SetRecordingState(hCam,0);
    22. abort = true;
    23. }
    24. }
    25. }
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  4. #4
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    Default Re: How to wait for events produced by non-Qt threads?

    If nothing else then maybe you don't need it at all?
    Your biological and technological distinctiveness will be added to our own. Resistance is futile.

    Please ask Qt related questions on the forum and not using private messages or visitor messages.


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