Fix freezes when trying to accelerate menu bar on Haiku

* src/haiku_support.cc (class EmacsWindow): New field
`menus_begun'.
(MenusBeginning): Don't send menu bar open events when that is
set, instead set it to true.
(BMenuBar_start_tracking): Stop locking the menu bar here and
send a special BE_MENU_BAR_OPEN event instead.
* src/haiku_support.h (struct haiku_menu_bar_state_event):
Delete field `no_lock'.
* src/haikumenu.c (Fhaiku_menu_bar_open):
* src/haikuterm.c (haiku_read_socket): Update accordingly.

src/haiku_support.cc

@@ -87,6 +87,8 @@ enum
     WAIT_FOR_RELEASE	= 3001,
     RELEASE_NOW		= 3002,
     CANCEL_DROP		= 3003,
+    SHOW_MENU_BAR	= 3004,
+    BE_MENU_BAR_OPEN	= 3005,
   };
 
 static color_space dpy_color_space = B_NO_COLOR_SPACE;
@@ -423,6 +425,7 @@ class EmacsWindow : public BWindow
   pthread_cond_t menu_update_cv = PTHREAD_COND_INITIALIZER;
   bool menu_updated_p = false;
   int window_id;
+  bool *menus_begun = NULL;
 
   EmacsWindow () : BWindow (BRect (0, 0, 0, 0), "", B_TITLED_WINDOW_LOOK,
 			    B_NORMAL_WINDOW_FEEL, B_NO_SERVER_SIDE_WINDOW_MODIFIERS)
@@ -902,19 +905,14 @@ class EmacsWindow : public BWindow
   MenusBeginning ()
   {
     struct haiku_menu_bar_state_event rq;
-    int lock_count = 0;
-    thread_id current_thread = find_thread (NULL);
-    thread_id window_thread = Thread ();
+    int lock_count;
+
     rq.window = this;
-    rq.no_lock = false;
+    lock_count = 0;
 
-    if (window_thread != current_thread)
-      rq.no_lock = true;
-
-    haiku_write (MENU_BAR_OPEN, &rq);
-
-    if (!rq.no_lock)
+    if (!menus_begun)
       {
+	haiku_write (MENU_BAR_OPEN, &rq);
 	while (IsLocked ())
 	  {
 	    ++lock_count;
@@ -932,6 +930,9 @@ class EmacsWindow : public BWindow
 	      gui_abort ("Failed to lock after cv signal denoting menu update");
 	  }
       }
+    else
+      *menus_begun = true;
+
     menu_bar_active_p = true;
   }
 
@@ -1244,6 +1245,37 @@ class EmacsMenuBar : public BMenuBar
 
     BMenuBar::MouseMoved (point, transit, msg);
   }
+
+  void
+  MessageReceived (BMessage *msg)
+  {
+    BRect frame;
+    BPoint pt, l;
+    EmacsWindow *window;
+    bool menus_begun;
+
+    if (msg->what == SHOW_MENU_BAR)
+      {
+	window = (EmacsWindow *) Window ();
+	frame = Frame ();
+	pt = frame.LeftTop ();
+	l = pt;
+	menus_begun = false;
+	Parent ()->ConvertToScreen (&pt);
+
+	window->menus_begun = &menus_begun;
+	set_mouse_position (pt.x, pt.y);
+	MouseDown (l);
+	window->menus_begun = NULL;
+
+	if (!menus_begun)
+	  msg->SendReply (msg);
+	else
+	  msg->SendReply (BE_MENU_BAR_OPEN);
+      }
+    else
+      BMenuBar::MessageReceived (msg);
+  }
 };
 
 class EmacsView : public BView
@@ -3748,20 +3780,18 @@ EmacsWindow_unzoom (void *window)
   w->UnZoom ();
 }
 
-/* Move the pointer into MBAR and start tracking.  */
-void
+/* Move the pointer into MBAR and start tracking.  Return whether the
+   menu bar was opened correctly.  */
+bool
 BMenuBar_start_tracking (void *mbar)
 {
   EmacsMenuBar *mb = (EmacsMenuBar *) mbar;
-  if (!mb->LockLooper ())
-    gui_abort ("Couldn't lock menubar");
-  BRect frame = mb->Frame ();
-  BPoint pt = frame.LeftTop ();
-  BPoint l = pt;
-  mb->Parent ()->ConvertToScreen (&pt);
-  set_mouse_position (pt.x, pt.y);
-  mb->MouseDown (l);
-  mb->UnlockLooper ();
+  BMessenger messenger (mb);
+  BMessage reply;
+
+  messenger.SendMessage (SHOW_MENU_BAR, &reply);
+
+  return reply.what == BE_MENU_BAR_OPEN;
 }
 
 #ifdef HAVE_NATIVE_IMAGE_API

src/haiku_support.h

@@ -328,7 +328,6 @@ struct haiku_menu_bar_resize_event
 struct haiku_menu_bar_state_event
 {
   void *window;
-  bool no_lock;
 };
 
 #define HAIKU_THIN 0
@@ -869,7 +868,7 @@ extern "C"
   be_translate_bitmap_from_memory (const void *buf, size_t bytes);
 #endif
 
-  extern void
+  extern bool
   BMenuBar_start_tracking (void *mbar);
 
   extern size_t

src/haikumenu.c

@@ -752,19 +752,24 @@ the position of the last non-menu event instead.  */)
   (Lisp_Object frame)
 {
   struct frame *f = decode_window_system_frame (frame);
+  int rc;
 
   if (FRAME_EXTERNAL_MENU_BAR (f))
     {
       block_input ();
       set_frame_menubar (f, 1);
-      BMenuBar_start_tracking (FRAME_HAIKU_MENU_BAR (f));
+      rc = BMenuBar_start_tracking (FRAME_HAIKU_MENU_BAR (f));
       unblock_input ();
+
+      if (!rc)
+	return Qnil;
+
+      FRAME_OUTPUT_DATA (f)->menu_bar_open_p = 1;
+      popup_activated_p += 1;
     }
   else
-    {
-      return call2 (Qpopup_menu, call0 (Qmouse_menu_bar_map),
-		    last_nonmenu_event);
-    }
+    return call2 (Qpopup_menu, call0 (Qmouse_menu_bar_map),
+		  last_nonmenu_event);
 
   return Qnil;
 }

src/haikuterm.c

@@ -3517,36 +3517,24 @@ haiku_read_socket (struct terminal *terminal, struct input_event *hold_quit)
 	  {
 	    struct haiku_menu_bar_state_event *b = buf;
 	    struct frame *f = haiku_window_to_frame (b->window);
+	    int was_waiting_for_input_p;
 
 	    if (!f || !FRAME_EXTERNAL_MENU_BAR (f))
 	      continue;
 
 	    if (type == MENU_BAR_OPEN)
 	      {
-		/* b->no_lock means that MenusBeginning was called
-		   from the main thread, which means tracking was
-		   started manually, and we have already updated the
-		   menu bar.  */
-		if (!b->no_lock)
-		  {
-		    BView_draw_lock (FRAME_HAIKU_VIEW (f), false, 0, 0, 0, 0);
-		    /* This shouldn't be here, but nsmenu does it, so
-		       it should probably be safe.  */
-		    int was_waiting_for_input_p = waiting_for_input;
-		    if (waiting_for_input)
-		      waiting_for_input = 0;
-		    set_frame_menubar (f, 1);
-		    waiting_for_input = was_waiting_for_input_p;
-		    BView_draw_unlock (FRAME_HAIKU_VIEW (f));
-		  }
+		was_waiting_for_input_p = waiting_for_input;
+		if (waiting_for_input)
+		  waiting_for_input = 0;
+
+		set_frame_menubar (f, 1);
+		waiting_for_input = was_waiting_for_input_p;
 
-		/* But set the flag anyway, because the menu will end
-		   from the window thread.  */
 		FRAME_OUTPUT_DATA (f)->menu_bar_open_p = 1;
 		popup_activated_p += 1;
 
-		if (!b->no_lock)
-		  EmacsWindow_signal_menu_update_complete (b->window);
+		EmacsWindow_signal_menu_update_complete (b->window);
 	      }
 	    else
 	      {