IOServicePortFromCGDisplayID is deprecated and crashing.

[Izzatbek]

IOServicePortFromCGDisplayID inside osxDisplayDeviceManager is crashing on my machine (10.11.6). We need to replace it.

[rob-smallshire]

I found this page while debugging my own code which uses code similar to IOServicePortFromCGDisplayID. I found you need to call CGGetOnlineDisplayList first, otherwise various calls in the implementation will hang.

Try something like this:

    const int MAX_DISPLAYS = 16;
    CGDisplayCount    displayCount, i;
    CGDisplayCount    maxDisplays = MAX_DISPLAYS;
    CGDirectDisplayID onlineDisplays[MAX_DISPLAYS];
    CGDisplayErr err = CGGetOnlineDisplayList(maxDisplays, onlineDisplays, &displayCount);
    if (err != kCGErrorSuccess) {
        fprintf(stderr, "CGGetOnlineDisplayList: error %d.\n", err);
        exit(1);
    }