On Wed, 16 Jun 2021 at 15:19, Akihiko Odaki <akihiko.od...@gmail.com> wrote:
>
> Signed-off-by: Akihiko Odaki <akihiko.od...@gmail.com>
> ---
> ui/cocoa.m | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 49 insertions(+)
Hi; I was looking at the cocoa.m code to see about maybe deleting the
unnecessary autorelease pools, and I ran into some code I was a bit
unsure about that was added in this patch.
In particular I'm wondering about the interactions across threads here.
> +- (void) updateUIInfo
> +{
> + NSSize frameSize;
> + QemuUIInfo info;
> +
> + if (!qemu_console_is_graphic(dcl.con)) {
> + return;
> + }
> +
> + if ([self window]) {
> + NSDictionary *description = [[[self window] screen]
> deviceDescription];
> + CGDirectDisplayID display = [[description
> objectForKey:@"NSScreenNumber"] unsignedIntValue];
> + NSSize screenSize = [[[self window] screen] frame].size;
> + CGSize screenPhysicalSize = CGDisplayScreenSize(display);
> +
> + frameSize = isFullscreen ? screenSize : [self frame].size;
> + info.width_mm = frameSize.width / screenSize.width *
> screenPhysicalSize.width;
> + info.height_mm = frameSize.height / screenSize.height *
> screenPhysicalSize.height;
> + } else {
> + frameSize = [self frame].size;
> + info.width_mm = 0;
> + info.height_mm = 0;
> + }
> +
> + info.xoff = 0;
> + info.yoff = 0;
> + info.width = frameSize.width;
> + info.height = frameSize.height;
> +
> + dpy_set_ui_info(dcl.con, &info);
This function makes some cocoa calls, and it also calls a QEMU
UI layer function, dpy_set_ui_info().
> +- (void)windowDidChangeScreen:(NSNotification *)notification
> +{
> + [cocoaView updateUIInfo];
We call it from the cocoa UI thread in callbacks like this.
> /* Called when the user clicks on a window's close button */
> - (BOOL)windowShouldClose:(id)sender
> {
> @@ -1936,6 +1983,8 @@ static void cocoa_switch(DisplayChangeListener *dcl,
>
> COCOA_DEBUG("qemu_cocoa: cocoa_switch\n");
>
> + [cocoaView updateUIInfo];
We also call it from the QEMU thread, when the QEMU thread calls
this cocoa_switch callback function.
(1) A question for Akihiko:
Are all the cocoa calls we make in updateUIInfo safe to
make from a non-UI thread? Would it be preferable for this
call in cocoa_switch() to be moved inside the dispatch_async block?
(Moving it would mean that I wouldn't have to think about whether
any of the code in it needs to have an autorelease pool :-))
(2) A question for Gerd:
Is it safe to call dpy_set_ui_info() from a non-QEMU-main-thread?
It doesn't appear to do any locking that would protect against
multiple threads calling it simultaneously.
thanks
-- PMM
