linux - Simple C Program that creates 2 X11 windows -

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i want create 2 windows in linux i'll later draw in separate thread. have non-deterministic bug second window create doesn't created (no errors though).

here code. 

static void create_x_window(display *display, window *win, int width, int height) {     int screen_num = defaultscreen(display);     unsigned long background = whitepixel(display, screen_num);     unsigned long border = blackpixel(display, screen_num);     *win = xcreatesimplewindow(display, defaultrootwindow(display), /* display, parent */         0,0, /* x, y */         width, height, /* width, height */         2, border, /* border width & colour */         background); /* background colour */     xselectinput(display, *win, buttonpressmask|structurenotifymask);     xmapwindow(display, *win);  }  int main(void) {     xinitthreads(); // prevent threaded xio errors     local_display = xopendisplay(":0.0");      window self_win, remote_win;     xevent self_event, remote_event;      create_x_window(local_display, &remote_win, 640,480);     // line flushes buffer , blocks window doesn't crash reason dont know yet     xnextevent(local_display, &remote_event);       create_x_window(local_display, &self_win, 320, 240);     // line flushes buffer , blocks window doesn't crash reason dont know yet     xnextevent(local_display, &self_event);      while (1) {      }     return 0; }

i don't care capturing input in windows, found tutorial had xselectinput , xnextevent (in event loop) , having trouble making work without either.

it's not bug, it's feature. you left out event loop.

although cleverly called xnextevent twice, x protocol asynchronous server may still setting actual window while call xnextevent, there nothing do.

tutorial here.


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