Open
Description
Hi, I'm still having some problems with select.select raising an exception "ValueError: filedescriptor out of range in select()" in src/prompt_toolkit/input/posix_utils.py", line 72 if the file descriptor number is too large (>1023). This happens when passing in a pipe instead of stdin during testing. It seems to be similar to problems that were already discussed in #354.
What makes this especially problematic is that the exception occurs inside the prompt loop which results in the prompt (and pytest) hanging indefinitely. A simple test to reproduce the problem:
import os
from typing import NamedTuple
import pytest
from prompt_toolkit import PromptSession
from prompt_toolkit.input import create_pipe_input
from prompt_toolkit.input.base import PipeInput
from prompt_toolkit.output import DummyOutput
@pytest.fixture
def prompt():
file_descriptors = []
try: # if an "OSError: Too many open files" is thrown, you may need to adjust the fp limit (`ulimit -n`)
for _ in range(512): # this should be enough to create a file descriptor > 1023
read_fd, write_fd = os.pipe()
file_descriptors.extend([read_fd, write_fd])
with create_pipe_input() as input_:
session = PromptSession(input=input_, output=DummyOutput())
yield Prompt(session, input_)
finally:
for fd in file_descriptors:
os.close(fd)
class Prompt(NamedTuple):
session: PromptSession
input: PipeInput
def test_too_many_open_files(prompt):
prompt.input.send_text(f"foobar\n")
# the prompt will hang if `select.select` is used because it causes an exception "filedescriptor out of range"
prompt.session.prompt("foobar")As discussed in #354, it is possible to easily fix this by replacing select.select with select.poll. I have added a patch which seemingly fixes this:
select_poll_patch.txt
Metadata
Metadata
Assignees
Labels
No labels