Re: [RFC PATCH-for-7.0 v3 2/2] ui/cocoa: run qemu_init in the main thread

["Philippe Mathieu-Daudé" <philippe.mathieu.daude@gmail.com>]

On 17/3/22 12:56, Philippe Mathieu-Daudé wrote:
> From: Paolo Bonzini <pbonzini@redhat.com>
> 
> Simplify the initialization dance by running qemu_init() in the main
> thread before the Cocoa event loop starts.  The cocoa_display_init()
> code that is post-applicationDidFinishLaunching: moves to the
> application delegate itself, and the secondary thread only runs
> the rest of qemu_main(), namely qemu_main_loop() and qemu_cleanup().
> 
> This fixes a case where addRemovableDevicesMenuItems() calls
> qmp_query_block() while expecting the main thread to still hold
> the BQL.  The newly-introduced assertions in the block layer
> complain about this.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> Message-Id: <20220307151004.578069-1-pbonzini@redhat.com>
> [PMD: Fixed trivial build failures & rebased]
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>   softmmu/main.c |  12 +++---
>   ui/cocoa.m     | 114 ++++++++++++++++++++-----------------------------
>   2 files changed, 54 insertions(+), 72 deletions(-)

> diff --git a/ui/cocoa.m b/ui/cocoa.m
> index 027c3053f7..2e5130d805 100644
> --- a/ui/cocoa.m
> +++ b/ui/cocoa.m
> @@ -100,14 +100,13 @@ static int last_buttons;
>   static int cursor_hide = 1;
>   static int left_command_key_enabled = 1;
>   static bool swap_opt_cmd;
> +static bool full_screen;
> +static bool full_grab;
> +static bool have_cocoa_ui;
>   
> -static int gArgc;
> -static char **gArgv;
>   static bool stretch_video;
>   static NSTextField *pauseLabel;
>   
> -static QemuSemaphore display_init_sem;
> -static QemuSemaphore app_started_sem;
>   static bool allow_events;
>   
>   static NSInteger cbchangecount = -1;
> @@ -115,6 +114,7 @@ static QemuClipboardInfo *cbinfo;
>   static QemuClipboardPeer cbpeer;
>   static QemuCocoaPasteboardTypeOwner *cbowner;
>   static QemuEvent cbevent;
> +static QemuThread main_thread;

This variable doesn't need to be in global scope, I'll
move it to applicationDidFinishLaunching().

> @@ -1323,8 +1310,22 @@ static CGEventRef handleTapEvent(CGEventTapProxy proxy, CGEventType type, CGEven
>   {
>       COCOA_DEBUG("QemuCocoaAppController: applicationDidFinishLaunching\n");
>       allow_events = true;
> -    /* Tell cocoa_display_init to proceed */
> -    qemu_sem_post(&app_started_sem);
> +
> +    // register vga output callbacks
> +    register_displaychangelistener(&dcl);
> +
> +    qemu_clipboard_peer_register(&cbpeer);
> +    qemu_mutex_unlock_iothread();
> +    qemu_thread_create(&main_thread, "qemu_main_loop", call_qemu_main_loop,
> +                       NULL, QEMU_THREAD_DETACHED);
> +
> +    if (full_screen) {
> +        [NSApp activateIgnoringOtherApps: YES];
> +        [self toggleFullScreen: nil];
> +    }
> +    if (full_grab) {
> +        [self setFullGrab: nil];
> +    }
>   }