Improve kill signal management

[ChillarAnand]

Describe the bug
Initially I found glances was consuming 100% CPU and thought it was a performance issue. Later I found that it is stale process.

To Reproduce

When glances is run in the terminal interactively, if CTRL + C is used to quit glances or when the terminal is closed forcefully, once in a while a stale process is left behind. I am not able to reproduce it consistently. I have been using glances from years but I am seeing this issue only from few weeks.

Expected behavior
No stale process should be there.

Desktop (please complete the following information):

$ glances --issue         
=====================================================================================================================================================================================
Glances 3.3.0.4 (/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/glances/__init__.py)
Python 3.9.12 (/Library/Frameworks/Python.framework/Versions/3.9/bin/python)
PsUtil 5.9.1 (/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/psutil/__init__.py)
=====================================================================================================================================================================================
alert         [OK]    0.00007s []
amps          [OK]    0.00026s []
cloud         [OK]    0.00008s {}
connections   [OK]    0.00024s {}
core          [OK]    0.00017s {'phys': 8, 'log': 8}
cpu           [OK]    0.00043s {'total': 26.1, 'user': 3.1, 'nice': 0.0, 'system': 2.5, 'idle': 94.5, 'time_since_update': 2.038684129714966, 'cpucore': 8, 'ctx_switches':
diskio        [OK]    0.00155s key=disk_name [{'time_since_update': 2.0400052070617676, 'disk_name': 'disk0', 'read_count': 4, 'write_count': 1, 'read_bytes': 32768, 'writ
docker        [OK]    0.00006s []
folders       [OK]    0.00006s []
fs            [OK]    0.00108s key=mnt_point [{'device_name': '/dev/disk3s1s1', 'fs_type': 'apfs', 'mnt_point': '/', 'size': 494384795648, 'used': 381701836800, 'free': 11
gpu           [OK]    0.00003s []
help          [OK]    0.00001s None
ip            [OK]    0.00007s {}
irq           [OK]    0.00004s []
load          [OK]    0.00006s {'min1': 3.58837890625, 'min5': 9.4169921875, 'min15': 5.4912109375, 'cpucore': 8}
mem           [OK]    0.00011s {'total': 8589934592, 'available': 3487072256, 'percent': 59.4, 'used': 5102862336, 'free': 3487072256, 'active': 3453976576, 'inactive': 33
memswap       [OK]    0.00013s {'total': 0, 'used': 0, 'free': 0, 'percent': 0.0, 'sin': 3070083072, 'sout': 14827520, 'time_since_update': 2.043797016143799}
network       [OK]    0.00226s key=interface_name [{'interface_name': 'lo0', 'alias': None, 'time_since_update': 2.0129363536834717, 'cumulative_rx': 335872, 'rx': 0, 'cum
now           [OK]    0.00003s 2022-11-16 15:37:10 IST
percpu        [OK]    0.00009s key=cpu_number [{'key': 'cpu_number', 'cpu_number': 0, 'total': 92.0, 'user': 0.0, 'system': 1.0, 'idle': 8.0, 'nice': 0.0}, {'key': 'cpu_nu
ports         [OK]    0.00031s []
processcount  [OK]    0.03994s {'total': 405, 'running': 405, 'sleeping': 0, 'thread': 794, 'pid_max': 0}
processlist   [OK]    0.00017s key=pid [{'gids': puids(real=20, effective=20, saved=20), 'memory_percent': 2.0017623901367188, 'pid': 378, 'cpu_percent': 4.8, 'cpu_times':
psutilversion [OK]    0.00004s (5, 9, 1)
quicklook     [OK]    0.00008s {'cpu': 26.1, 'percpu': [{'key': 'cpu_number', 'cpu_number': 0, 'total': 92.0, 'user': 0.0, 'system': 1.0, 'idle': 8.0, 'nice': 0.0}, {'key'
raid          [OK]    0.00001s {}
sensors       [OK]    0.00000s key=label [{'label': 'Battery', 'value': 58, 'unit': '%', 'status': 'Discharging', 'type': 'battery', 'key': 'label'}]
smart         [NA]
system        [OK]    0.00000s {'os_name': 'Darwin', 'hostname': 'Anands-MacBook-Air.local', 'platform': '64bit', 'os_version': '13.0.1', 'hr_name': 'Darwin 13.0.1 64bit'}
uptime        [OK]    0.00002s {'seconds': 206}
wifi          [OK]    0.00001s []
=====================================================================================================================================================================================
Total time to update all stats: 0.05213s
=============================================================================================================================================================================== 3.18s

Additional context

As a temporary workaround, I am running glances using the following command.

$ sudo pkill -f glances; sudo glances --theme-white --process-short-name --byte -t 4 --config ~/glances.conf                                                                       

[nicolargo]

@ChillarAnand thanks for the issue report.

Anything in the Glances log file ?

[ChillarAnand]

There are couple of exceptions and error messages. But I am not sure if they are related.

Posted entire log here. https://gist.github.com/ChillarAnand/07e61f31cf89d794cb9615b4e1210399.

[ChillarAnand]

Steps to reproduce:

Open new tab in terminal.
Run glances with sudo.
Without quitting glances, close the terminal.

I think terminal is trying to close glances. Since glances was started with sudo, it is not able to kill the process.

It works fine, if we run glances without sudo.

[RazCrimson]

@ChillarAnand
I can't reproduce this on my end using Konsole on Arch Linux.

Could you just confirm if you are able to reproduce the issue with maybe another terminal manager?

[ChillarAnand]

@RazCrimson I was experiencing this issue on Mac with the Terminal application.

Just tried with iTerm on Mac and I am not able to reproduce it.

[nicolargo]

@ChillarAnand i found the issue. When a terminal is closed, it sent a SIGHUP signal to the running process. Glances only catch the SIGINT signal.

Correction will be done on the develop branch.

Thanks for the issue report @ChillarAnand !

[nicolargo]

Corrected on the develop branch.

Will be released in Glances 3.4.0.