4 ms·

If something mission critical is happening in a GUI dependent on Qt, it seems like even the most rudimentary timing analysis of the requirements could have reve

If something mission critical is happening in a GUI dependent on Qt, it seems like even the most rudimentary timing analysis of the requirements could have revealed that Qt is not a good solution for that. I fail to see any relevant insights here.

rat9988 4y ago
it seems like even the most rudimentary timing analysis of the requirements could have revealed that Qt is not a good solution for that. How do you deduce this without studying it? Or someone else studying it for you?
- daoist_shaman 4y ago
  Graphics and graphical processing take orders of magnitude longer than other fundamental machine instructions. It's just inherently slower than doing something equivalent that requires zero graphical processing or monitoring of user input. It is common sense to anyone who knows the tech stack that underlies the pixels on the screen. This is no fault of Qt by any means. It's just the nature of the tech.
  - rat9988 4y ago
    But he is testing slots and signals, which are not tied to GUI.
Woodi 4y ago
> mission critical is happening in a GUI Example pleas ? That "mission critical" and "in GUI" is kind of strange... But if you just talking about "human reaction is needed" time then 10 x virtual function call time don't looks so bad...
- inferiorhuman 4y ago
  https://www.qt.io/industry/qt-in-automotive https://www.qt.io/industry/qt-in-automotive
  - Woodi 4y ago
    So, Qt Company clearly states Qt is up to the task. Even they hope to make money from it :) Just hope they (Qt Co.) hear about that ship with touch interfaces accident. But still, "GUI _reaction_ time" is not a problem while interacting with humans. I would more worry about replacing mechanic/hydraulic subsystems with electronis - just in case EMP bomb in neighborhood. Or last years favourite - pilot's decisions overriding... Because it's captain/pilot/driver who should have final decision to make - nothing better invented so far and not I would not recommended to change that. Some limited Skynet-like incidents are not hard to imagine...
    - inferiorhuman 4y ago
      Just hope they (Qt Co.) hear about that ship with touch interfaces accident. Yeah I'm in camp mechanical user interfaces, but… But still, "GUI _reaction_ time" is not a problem while interacting with humans. Sure it is. People interact with this crap while driving all the time. They shouldn't but they do. A sluggish interface could absolutely be a major distraction.
simonh 4y ago
Why would Qt not be suitable?
323 4y ago
Some version of Qt is safety-critical certified, for example you can use it to display GUIs in medical devices: * road vehicles functional safety * railway software applications * electrical / electronic safety-related systems * medical device software- software life-cycle processes https://www.qt.io/product/functional-safety-and-qt https://www.qt.io/product/functional-safety-and-qt

rat9988 4y ago

it seems like even the most rudimentary timing analysis of the requirements could have revealed that Qt is not a good solution for that. How do you deduce this without studying it? Or someone else studying it for you?

daoist_shaman 4y ago
Graphics and graphical processing take orders of magnitude longer than other fundamental machine instructions. It's just inherently slower than doing something equivalent that requires zero graphical processing or monitoring of user input. It is common sense to anyone who knows the tech stack that underlies the pixels on the screen. This is no fault of Qt by any means. It's just the nature of the tech.
- rat9988 4y ago
  But he is testing slots and signals, which are not tied to GUI.

Woodi 4y ago

> mission critical is happening in a GUI Example pleas ? That "mission critical" and "in GUI" is kind of strange... But if you just talking about "human reaction is needed" time then 10 x virtual function call time don't looks so bad...

inferiorhuman 4y ago
https://www.qt.io/industry/qt-in-automotive https://www.qt.io/industry/qt-in-automotive
- Woodi 4y ago
  So, Qt Company clearly states Qt is up to the task. Even they hope to make money from it :) Just hope they (Qt Co.) hear about that ship with touch interfaces accident. But still, "GUI _reaction_ time" is not a problem while interacting with humans. I would more worry about replacing mechanic/hydraulic subsystems with electronis - just in case EMP bomb in neighborhood. Or last years favourite - pilot's decisions overriding... Because it's captain/pilot/driver who should have final decision to make - nothing better invented so far and not I would not recommended to change that. Some limited Skynet-like incidents are not hard to imagine...
  - inferiorhuman 4y ago
    Just hope they (Qt Co.) hear about that ship with touch interfaces accident. Yeah I'm in camp mechanical user interfaces, but… But still, "GUI _reaction_ time" is not a problem while interacting with humans. Sure it is. People interact with this crap while driving all the time. They shouldn't but they do. A sluggish interface could absolutely be a major distraction.

simonh 4y ago

Why would Qt not be suitable?

323 4y ago

Some version of Qt is safety-critical certified, for example you can use it to display GUIs in medical devices: * road vehicles functional safety * railway software applications * electrical / electronic safety-related systems * medical device software- software life-cycle processes https://www.qt.io/product/functional-safety-and-qt https://www.qt.io/product/functional-safety-and-qt