laurensvalk
commented
3 months ago Good find! When not connected, it is supposed to ignore printed output but that clearly isn't happening.
Open BertLindeman opened 3 months ago
laurensvalk
commented
3 months ago Good find! When not connected, it is supposed to ignore printed output but that clearly isn't happening.
laurensvalk
commented
3 months ago Did you try this on any other hub?
BertLindeman
commented
3 months ago Did you try this on any other hub?
Up to now only the Spike and Inventor. Will "do" others.
laurensvalk
commented
3 months ago More minimal program and method below.
Run this on SPIKE Prime and press the disconnect button in Pybricks Code. No need to restart anything.
while True:
print(f'hello - hello - hello - hello - hello - hello - hello')
print(f'hello - hello - hello - hello - hello - hello - hello')The hub doesn't quite crash all the way, but the animation still visibly stutters. Just for less than it needs for the watchdog timer to trigger.
laurensvalk
commented
3 months ago Yet this is OK. So I guess we'll have to have a look at the format-string source code:
while True:
print('hello - hello - hello - hello - hello - hello - hello')
print('hello - hello - hello - hello - hello - hello - hello')This one stutters:
while True:
print(f'{"hello":>10} -{"hello":>10} {"hello":>10} {"hello":>10} {"hello":>10}')
print(f'{"hello":>10} -{"hello":>10} {"hello":>10} {"hello":>10} {"hello":>10}')
print(f'{"hello":>10} -{"hello":>10} {"hello":>10} {"hello":>10} {"hello":>10}')
print(f'{"hello":>10} -{"hello":>10} {"hello":>10} {"hello":>10} {"hello":>10}')Yes, any long f'string' seems to be an issue. Normal strings seem fine.
BertLindeman
commented
3 months ago Did you try this on any other hub?
How to "see" the stutter the other hubs? I have the Move / City / 2 Technic hubs running with 8 of these print lines. The inventor and prime hub stop automagically but the others run happily on. Maybe the blue light is a bit more step by step. But now very clear.
laurensvalk
commented
3 months ago Thanks for having a look! Since it seems to be specifically related to these format strings, I think it's OK to stick to just the primehub for now to keep it simple.
Thanks for bringing it to our attention. I haven't used these f-strings much in Pybricks for some reason.
BertLindeman
commented
3 months ago Thanks for having a look! Since it seems to be specifically related to these format strings, I think it's OK to stick to just the primehub for now to keep it simple.
Thanks for bringing it to our attention. I haven't used these f-strings much in Pybricks for some reason.
I like the f-strings more and more. Just getting to know the formatting characters.
BTW this was the issue I found while testing the BT-on/off change in build 3380.
BertLindeman
commented
3 months ago You know me, I keep fiddling 😄
Idea was does the f-string pose the problem or the print doing the formatting.
This snippet:
formatted1 = f'{"hello" * 3:>20} - {"wow"[:2]:>10} {"hello":>10} {"hello":>10} {"hello":>10}'
print(type(formatted1))
formatted2 = f'{formatted1[:10]:>20}'
while True:
formatted2 = f'{formatted1[:10]:>20}'
print(type(formatted1), formatted1)
print(formatted2)
print(type(formatted1), formatted1)
with an f-string in the loop makes the animation stutter.
The same program but the formatting commented out within the loop does not stutter:
formatted1 = f'{"hello" * 3:>20} - {"wow"[:2]:>10} {"hello":>10} {"hello":>10} {"hello":>10}'
print(type(formatted1))
formatted2 = f'{formatted1[:10]:>20}'
while True:
# formatted2 = f'{formatted1[:10]:>20}'
print(type(formatted1), formatted1)
print(formatted2)
print(type(formatted1), formatted1)The watchdog is not triggered.
The 3 print commands are needed to see the stutter.
[EDIT]
Without the print statements in the loop, but with f-strings "that do formatting on slices" the running display animation is skipping frames, in my terms it stutters.
With SLICE = False the normal display animation.
Describe the bug Program is a tight loop printing f-strings. Within seconds the hub does a shutdown (somehow) The display animation is no longer smooth but has large hickups.
Might this be related to #436 ?
To reproduce Steps to reproduce the behavior:
Aditional info Connected the hub before the test to USB to keep the power on. After the crash connect to the hub and go to the REPL. Showed:
Expected behavior You'd expect the program to just keep running and not to power-off.
Screenshots There is a saying that a picture is worth a 1000 words. Screenshots really help to identify and solve problems.
test program for this issue
```python # issues try_movehub_on_prime_6 # start this and while running disconnect with the app # stop the hub to save the current program # restart the hub (if build 3380 installed press the BT button -> red) # start the program with the button, and # within seconds the running square stops and the hub shutsdown from pybricks.hubs import PrimeHub from pybricks.tools import wait HUB = PrimeHub() # Initialize variables. color_list = ["", "", "", "", "", "", ""] _rand = HUB.battery.current() + HUB.battery.voltage() # _rand = 123 INDEX = 4 A = 0 B = 5 def main2(): while True: print(f'pre _rand {_rand:>5} A {A:>2} B {B:>2}', end=" ") print(f'_rand {_rand:>5} A {A:>2} B {B:>2}') print(f'INDEX {INDEX:>3} color_list[{INDEX}] {color_list[INDEX]}') # wait(1) # with 1ms second wait: no problem wait(0.75) # this wait is not enough to prevent the error main2() ```