Re: [Texmacs-dev] Constant Use of 100% CPU

[Sebastian Miele]

Applying

  diff --git a/src/Plugins/Qt/qt_gui.cpp b/src/Plugins/Qt/qt_gui.cpp
  index 22b21d2cd..5fcb0fb26 100644
  --- a/src/Plugins/Qt/qt_gui.cpp
  +++ b/src/Plugins/Qt/qt_gui.cpp
  @@ -836,7 +836,10 @@ qt_gui_rep::update () {
     if (interrupted)               needing_update = true;
     if (nr_windows == 0)           qApp->quit();

  -  time_t delay = delayed_commands.lapse - texmacs_time();
  +  time_t delay = (0 < N(delayed_commands.q))
  +               ? (delayed_commands.lapse - texmacs_time())
  +               : std_delay;
  +
     if (needing_update) delay = 0;
     else                delay = max (0, min (std_delay, delay));
     if (postpone_treatment) delay= 100; // NOTE: force occasional display

seems to produce no problems and solves the bug. (At least the bug that
I experienced and debugged. I do not know whether there are more 100%
CPU bugs.) I found it with:

  diff --git a/src/Plugins/Qt/qt_gui.cpp b/src/Plugins/Qt/qt_gui.cpp
  index 22b21d2cd..b3a0d9102 100644
  --- a/src/Plugins/Qt/qt_gui.cpp
  +++ b/src/Plugins/Qt/qt_gui.cpp
  @@ -836,10 +836,26 @@ qt_gui_rep::update () {
     if (interrupted)               needing_update = true;
     if (nr_windows == 0)           qApp->quit();

  -  time_t delay = delayed_commands.lapse - texmacs_time();
  +  time_t now_1 = texmacs_time();
  +  time_t lapse = delayed_commands.lapse;
  +  time_t delay = lapse - now_1;
  +
     if (needing_update) delay = 0;
     else                delay = max (0, min (std_delay, delay));
     if (postpone_treatment) delay= 100; // NOTE: force occasional display
  +
  +  if( delay <= 0 )
  +    {
  +      const command_queue& q = delayed_commands;
  +      cout << '\n'
  +           << "         now_1: " << now_1          << '\n'
  +           << " lapse - now_1: " << lapse - now_1  << '\n'
  +           << "needing_update: " << needing_update << '\n'
  +           << "         delay: " << delay          << '\n'
  +           << "        q.wait: " << q.wait         << '\n'
  +           << "       q.lapse: " << q.lapse        << '\n'
  +           << " q.start_times: " << q.start_times  << LF;
  +    }

     updatetimer->start (delay);
     updating = false;

When the bug appears, that procudes a lot of

           now_1: 46233
   lapse - now_1: -41
  needing_update: false
           delay: 0
          q.wait: false
         q.lapse: 46192
   q.start_times: [ ]

where q.lapse and q.start_times stay constant, now_1 increases, and
lapse - now_1 decreases. The lapse is used without checking whether the
queue is empty. I do not understand command_queue. But if the queue is
empty, a lapse (other than +inf) probably does not make sense.