[Linux] wait_procs seemingly ignoring timeout, TimeoutExpired thrown

[guille]

Summary

• OS: Ubuntu 18.04
• Architecture: 64bit
• Psutil version: Both 5.6.1 and 5.8.0
• Python version: 3.7.5
• Type: core

Description

The bug can be reproduced by creating these two files and running python a.py:

a.py:

import signal
import subprocess
import psutil
import time

my_process = subprocess.Popen(["python", "b.py"])
time.sleep(2)
try:
    my_process.send_signal(signal.SIGTERM)
    _, alive = psutil.wait_procs([my_process], timeout=5)
    if alive:
        alive[0].kill()
        psutil.wait_procs(alive, timeout=5)

except Exception as exc:
    print("Sigterm failed: ", str(exc))

b.py

import time
import signal

def handler(_signum, _frame):
    time.sleep(5)

signal.signal(signal.SIGTERM, handler)

time.sleep(50)

On my machine, this will print Sigterm failed Command '['python', 'b.py']' timed out after 1.0 seconds. Exception is an instance of subprocess.TimeoutExpired. By debugging a bit I see that this piece of code is where the exception initially appears. And since psutil.TimeoutExpired and subprocess.TimeoutExpired are different, it doesn't get caught.

I'm sure I'm doing something wrong as the example in the documentation is using a higher timeout, but I can't see the problem.