Signals are not handled

[olivierlemasle]

Feature

Signal does not seem to work with RustPython.

With the following Python file test_signal.py:

import signal
import sys

def signal_handler(signum, frame):
    print('\nSignal handler called with signal', signum)
    sys.exit(0)

signal.signal(signal.SIGQUIT, signal_handler)
signal.signal(signal.SIGINT, signal_handler)

while True:
    input(">>")

With CPython, when running python test_signal.py:

• typing Ctrl+C or sending SIGINT (e.g. with pkill -INT -ef test_signal.py) exits the process with code 0, and Signal handler called with signal 2 is printed.
• typing Ctrl+\ or sending SIGQUIT (e.g. with pkill -QUIT -ef test_signal.py) exits the process with code 0, and Signal handler called with signal 3 is printed.

With RustPython (compiled from main (af884cb), when running rustpython test_signal.py:

• typing Ctrl+C or Ctrl+\ exists the process with error code 130, and a KeyboardInterrupt message is printed:

   Traceback (most recent call last):
     File "test_signal.py", line 12, in <module>
       input(">>")
   KeyboardInterrupt
  

• sending SIGINT or SIGQUIT has no effect

Python Documentation or reference to CPython source code

https://docs.python.org/3/library/signal.html

[youknowone]

@coolreader18 do you have any idea about this?

[coolreader18]

Probably vm/src/stdlib/builtins.rs:418 should call the signal handler instead of unconditionally throwing a KeyboardInterrupt

[andreistan26]

The problem is that rustyline disables these signals from termios. I've opened an issue on their side to add a config option for this kkawakam/rustyline#757.

https://github.com/kkawakam/rustyline/blob/c01855af1cbfe1f3ded3f7bfbde5efab17a78240/src/tty/unix.rs#L1568

        // disable echoing, canonical mode, extended input processing and signals
        raw.c_lflag &= !(termios::ECHO | termios::ICANON | termios::IEXTEN | termios::ISIG);

[youknowone]

The linked issue in rustyline looks resolved. Is this issue also solved?

[andreistan26]

Yep, submitted the PR a while ago. The issue is not solved though. The setup for rustyline needs to change a bit. If i get some time i will take a look at it.