Re: [Qemu-devel] [PATCH v3] ui/cocoa.m: add Speed menu

[Peter Maydell]

On 14 June 2017 at 04:17, Programmingkid <address@hidden> wrote:
> Programs running inside of QEMU can sometimes use more CPU time than is really
> needed. To solve this problem, we just need to throttle the virtual CPU. This
> feature will stop laptops from burning up.
>
> This patch adds a menu called Speed that has menu items from 100% to 1% that
> represent the speed options. 100% is full speed and 1% is slowest.
>
> Signed-off-by: John Arbuckle <address@hidden>
> ---
> v3 changes:
> Changed the item deselection loop.
> Moved speed calculation equation to main function.
> Replaced "%c" with "%%".
> Changed how 100% menu item is made.
>
> v2 changes:
> Fixed missing space with 'if' and 'for' structures.
> Fixed tab damage.
> Use loop to create menu items.
> Changed name of menu items to use percentages.
> Use tags to determine selected menu item.

> +    // Add the rest of the Speed menu items
> +    int p, percentage, throttle_pct;
> +    for (p = 10; p >= 0; p--)
> +    {
> +        percentage = p * 10 > 1 ? p * 10 : 1; // prevent a 0% menu item
> +
> +        if (percentage == 100) {
> +            [menuItem setState: NSOnState];
> +        }
> +        menuItem = [[[NSMenuItem alloc]
> +                   initWithTitle: [NSString stringWithFormat: @"%d%%", 
> percentage] action:@selector(adjustSpeed:) keyEquivalent:@""] autorelease];

Here you try to call setState: on the menuItem before
you allocate it -- these lines should be the other way
around. (The effect is that the 100% item isn't ticked
on startup.)

> +
> +        /* Calculate the throttle percentage */
> +        throttle_pct = -1 * percentage + 100;
> +
> +        [menuItem setTag: throttle_pct];
> +        [menu addItem: menuItem];
> +    }

That's a very minor fix, so I'll just make it locally
when I apply this patch to master.

thanks
-- PMM