im gonna explain my structure step by step

i have a widget including a button and a label
label has a png as background.
when i click on button a thread is being created
that thread draws a line chart on that label

here is my problem:
when i move my mouse on the png ,my application exits with segmentation fault


i read data from an array to draw the chart. i update array in another thread.
i have 2 mutexes to make my threads work consecutively. "1 update 1 draw" i mean.
draw function adds lines to my scene/view

another problem:
if i dont call msleep(30+) after each loop in each thread my program exits with fault again
30+ = ms under 30 doesnt work also

if needed i can post my code.
i need ur help.

have a good day every1

ersin özkan
turkey