HUD denial of service

Status changed to 'Confirmed' because the bug affects multiple users.

I can confirm the same problem occurs on my install - but the hud CPU hasn't yet recovered after approximately 10 minutes.

a lot of this is bug 938584

we could also add a maximum string length limitation (because larger searches take longer to complete)

the hud UI could also refuse to submit a new search while one is still in progress to prevent the stacking effect (that causes it to take 10 minutes for the CPU to clear up). another possibility is that it will only submit a search after the user has stopped typing for a short interval (100-200ms?)

Both of my suggestions for how to fix this need to be completed in Unity. We could put the string length limitation in hud-service but to do so would be bad because the user interface would still allow longer strings to be entered -- we would simply ignore them. The limitation needs to be in the UI.

The other part of fixing this -- which is not submitting a query while one is still active -- definitely can only be done in the front-end.

After the commit that Gord noted in unity on 2012-03-30, is there anything left in this ticket not duplicated by bug 938584 ?

indicator-appmenu (0.3.96-0ubuntu3) precise; urgency=low

  * Backport desrt's performance improvement work:
    - reduce hud cpu usage and DoS on long strings (lp: #938584, ##948820)
    - should stop stripping issues (lp: #937020)
    - fixes a small leak (lp: #972354)

This bug was fixed in the package unity - 5.10.0-0ubuntu3

---------------
unity (5.10.0-0ubuntu3) precise-proposed; urgency=low

  [ Oliver Grawert ]
  * Enable subarch specific quilt support
  * add linaros disable_standalone-clients.patch to make unity build with GLES

  [ Didier Roche ]
  * remove a symlink and replace with a real file for
    debian/patches/series.<arch> as not supported in non v3 (and we don't
    want v3 format with full source upstream derived branch)

unity (5.10.0-0ubuntu2) precise-proposed; urgency=low

  [ Ricardo Salveti de Araujo ]
  * Enabling build with OpenGL ES2.0 support for ARM and disable maintainer
     mode on that arch to avoid -Werror failure (LP: #980544)

unity (5.10.0-0ubuntu1) precise-proposed; urgency=low

  * New upstream release:
    - bamfdaemon crashed with SIGABRT in g_assertion_message() (LP: #926208)
    - We are using 1 bad hack for compiz hanging on startup (LP: #963264)
    - GConf backend steals glib events from compiz (LP: #965220)
    - when I closed QupZill brawser it crashed and then and then I sow
      worrning that compiz crashed but fire fox and chrome is estle working.
      gtk-window-decorator crashed with SIGSEGV in max_window_name_width()
      (LP: #948580)
    - compiz crashed with SIGSEGV in std::basic_string<...>::basic_string()
      from unity::launcher::HudLauncherIcon::HudLauncherIcon()::{lambda} from
      unity::UBusManager::OnCallback (LP: #964897)
    - unity-panel-service crashed due to heap corruption in g_free() from
      service_proxy_name_changed() [libindicator/indicator-service-
      manager.c:574] (LP: #969360)
    - Opening dash while an application is maximized makes unity completely
      useless, have to relogin (LP: #975103)
    - unity crash on alt-tab (LP: #975168)
    - Top bar - Menus should be condensed to fit panel/overlay of appmenu
      (LP: #655184)
    - Topbar - window controls for maximised windows in the top bar should
      conform to Fitts's law (LP: #839690)
    - [FFe, UIFe] Dash - When the Dash is open and there is a maximised app in
      the background, the top bar background should not disappear
      (LP: #839480)
    - Dash - The inner bottom left, bottom right and top right corners of the
      desktop dash border are rendered incorrectly (LP: #839476)
    - Showdesktoped window contents invisible in window spread (LP: #877778)
    - Maximized windows can be accidentally closed from wrong monitor.
      (LP: #865701)
    - Unity launcher on-screen corruption on resume from suspend with nVidia
      proprietary driver (LP: #915265)
    - Launcher - Inserting items into launcher makes unnecessary animations on
      other monitors (LP: #925021)
    - Far left character in panel (and launcher popups) distorted
      (LP: #927441)
    - Jenkins build failure: SetAcceptKeyNavFocusOnMouseEnter not declared
      (LP: #938037)
    - super+<unbound key> and sometimes super+<number> keys now cause launch
      to wedge with the key hints shown and retains focus instead of selecting
      the requested window (LP: #934084)
    - three-finger move does not move (Precise) (LP: #940612)
    - compiz crashed with SIGSEGV in std::__de...