Description
Snekbox hangs while reading stdout from the NsJail processes. This is handled by NsJail._consume_stdout(). The specific line it hangs on is
|
chars = nsjail.stdout.read(READ_CHUNK_SIZE) |
I believe this happens because the amount of bytes being read is larger than the amount that's in stdout. Hence, the read() call waits until enough bytes become available to satisfy the requested amount.
Reproduction
Run the following commands
pipenv run devsh
python -m snekbox 'print("hello")' --time_limit 0Wait and observe that Snekbox is not terminating. Press ctrl + c to see the following traceback appear
Traceback (most recent call last):
File "/usr/local/lib/python3.10/runpy.py", line 196, in _run_module_as_main
return _run_code(code, main_globals, None,
File "/usr/local/lib/python3.10/runpy.py", line 86, in _run_code
exec(code, run_globals)
File "/home/mark/repos/python/snekbox/snekbox/__main__.py", line 35, in <module>
main()
File "/home/mark/repos/python/snekbox/snekbox/__main__.py", line 30, in main
result = NsJail().python3(args.code, nsjail_args=args.nsjail_args, py_args=args.py_args)
File "/home/mark/repos/python/snekbox/snekbox/nsjail.py", line 183, in python3
output = self._consume_stdout(nsjail)
File "/home/mark/repos/python/snekbox/snekbox/nsjail.py", line 120, in _consume_stdout
chars = nsjail.stdout.read(READ_CHUNK_SIZE)
KeyboardInterrupt
Description
Snekbox hangs while reading stdout from the NsJail processes. This is handled by
NsJail._consume_stdout(). The specific line it hangs on issnekbox/snekbox/nsjail.py
Line 120 in 94627e2
I believe this happens because the amount of bytes being read is larger than the amount that's in stdout. Hence, the
read()call waits until enough bytes become available to satisfy the requested amount.Reproduction
Run the following commands
pipenv run devsh python -m snekbox 'print("hello")' --time_limit 0Wait and observe that Snekbox is not terminating. Press ctrl + c to see the following traceback appear