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from __future__ import annotations
import errno
import os
import select
import sys
from typing import TYPE_CHECKING
import pytest
from .. import _core
from .._core._tests.tutil import gc_collect_harder, skip_if_fbsd_pipes_broken
from ..testing import check_one_way_stream, wait_all_tasks_blocked
posix = os.name == "posix"
pytestmark = pytest.mark.skipif(not posix, reason="posix only")
assert not TYPE_CHECKING or sys.platform == "unix"
if posix:
from .._unix_pipes import FdStream
else:
with pytest.raises(ImportError):
from .._unix_pipes import FdStream
async def make_pipe() -> tuple[FdStream, FdStream]:
"""Makes a new pair of pipes."""
(r, w) = os.pipe()
return FdStream(w), FdStream(r)
async def make_clogged_pipe():
s, r = await make_pipe()
try:
while True:
# We want to totally fill up the pipe buffer.
# This requires working around a weird feature that POSIX pipes
# have.
# If you do a write of <= PIPE_BUF bytes, then it's guaranteed
# to either complete entirely, or not at all. So if we tried to
# write PIPE_BUF bytes, and the buffer's free space is only
# PIPE_BUF/2, then the write will raise BlockingIOError... even
# though a smaller write could still succeed! To avoid this,
# make sure to write >PIPE_BUF bytes each time, which disables
# the special behavior.
# For details, search for PIPE_BUF here:
# http://pubs.opengroup.org/onlinepubs/9699919799/functions/write.html
# for the getattr:
# https://bitbucket.org/pypy/pypy/issues/2876/selectpipe_buf-is-missing-on-pypy3
buf_size = getattr(select, "PIPE_BUF", 8192)
os.write(s.fileno(), b"x" * buf_size * 2)
except BlockingIOError:
pass
return s, r
async def test_send_pipe() -> None:
r, w = os.pipe()
async with FdStream(w) as send:
assert send.fileno() == w
await send.send_all(b"123")
assert (os.read(r, 8)) == b"123"
os.close(r)
async def test_receive_pipe() -> None:
r, w = os.pipe()
async with FdStream(r) as recv:
assert (recv.fileno()) == r
os.write(w, b"123")
assert (await recv.receive_some(8)) == b"123"
os.close(w)
async def test_pipes_combined() -> None:
write, read = await make_pipe()
count = 2**20
async def sender() -> None:
big = bytearray(count)
await write.send_all(big)
async def reader() -> None:
await wait_all_tasks_blocked()
received = 0
while received < count:
received += len(await read.receive_some(4096))
assert received == count
async with _core.open_nursery() as n:
n.start_soon(sender)
n.start_soon(reader)
await read.aclose()
await write.aclose()
async def test_pipe_errors() -> None:
with pytest.raises(TypeError):
FdStream(None)
r, w = os.pipe()
os.close(w)
async with FdStream(r) as s:
with pytest.raises(ValueError, match="^max_bytes must be integer >= 1$"):
await s.receive_some(0)
async def test_del() -> None:
w, r = await make_pipe()
f1, f2 = w.fileno(), r.fileno()
del w, r
gc_collect_harder()
with pytest.raises(OSError, match="Bad file descriptor$") as excinfo:
os.close(f1)
assert excinfo.value.errno == errno.EBADF
with pytest.raises(OSError, match="Bad file descriptor$") as excinfo:
os.close(f2)
assert excinfo.value.errno == errno.EBADF
async def test_async_with() -> None:
w, r = await make_pipe()
async with w, r:
pass
assert w.fileno() == -1
assert r.fileno() == -1
with pytest.raises(OSError, match="Bad file descriptor$") as excinfo:
os.close(w.fileno())
assert excinfo.value.errno == errno.EBADF
with pytest.raises(OSError, match="Bad file descriptor$") as excinfo:
os.close(r.fileno())
assert excinfo.value.errno == errno.EBADF
async def test_misdirected_aclose_regression() -> None:
# https://github.com/python-trio/trio/issues/661#issuecomment-456582356
w, r = await make_pipe()
old_r_fd = r.fileno()
# Close the original objects
await w.aclose()
await r.aclose()
# Do a little dance to get a new pipe whose receive handle matches the old
# receive handle.
r2_fd, w2_fd = os.pipe()
if r2_fd != old_r_fd: # pragma: no cover
os.dup2(r2_fd, old_r_fd)
os.close(r2_fd)
async with FdStream(old_r_fd) as r2:
assert r2.fileno() == old_r_fd
# And now set up a background task that's working on the new receive
# handle
async def expect_eof() -> None:
assert await r2.receive_some(10) == b""
async with _core.open_nursery() as nursery:
nursery.start_soon(expect_eof)
await wait_all_tasks_blocked()
# Here's the key test: does calling aclose() again on the *old*
# handle, cause the task blocked on the *new* handle to raise
# ClosedResourceError?
await r.aclose()
await wait_all_tasks_blocked()
# Guess we survived! Close the new write handle so that the task
# gets an EOF and can exit cleanly.
os.close(w2_fd)
async def test_close_at_bad_time_for_receive_some(
monkeypatch: pytest.MonkeyPatch,
) -> None:
# We used to have race conditions where if one task was using the pipe,
# and another closed it at *just* the wrong moment, it would give an
# unexpected error instead of ClosedResourceError:
# https://github.com/python-trio/trio/issues/661
#
# This tests what happens if the pipe gets closed in the moment *between*
# when receive_some wakes up, and when it tries to call os.read
async def expect_closedresourceerror() -> None:
with pytest.raises(_core.ClosedResourceError):
await r.receive_some(10)
orig_wait_readable = _core._run.TheIOManager.wait_readable
async def patched_wait_readable(*args, **kwargs) -> None:
await orig_wait_readable(*args, **kwargs)
await r.aclose()
monkeypatch.setattr(_core._run.TheIOManager, "wait_readable", patched_wait_readable)
s, r = await make_pipe()
async with s, r:
async with _core.open_nursery() as nursery:
nursery.start_soon(expect_closedresourceerror)
await wait_all_tasks_blocked()
# Trigger everything by waking up the receiver
await s.send_all(b"x")
async def test_close_at_bad_time_for_send_all(monkeypatch: pytest.MonkeyPatch) -> None:
# We used to have race conditions where if one task was using the pipe,
# and another closed it at *just* the wrong moment, it would give an
# unexpected error instead of ClosedResourceError:
# https://github.com/python-trio/trio/issues/661
#
# This tests what happens if the pipe gets closed in the moment *between*
# when send_all wakes up, and when it tries to call os.write
async def expect_closedresourceerror() -> None:
with pytest.raises(_core.ClosedResourceError):
await s.send_all(b"x" * 100)
orig_wait_writable = _core._run.TheIOManager.wait_writable
async def patched_wait_writable(*args, **kwargs) -> None:
await orig_wait_writable(*args, **kwargs)
await s.aclose()
monkeypatch.setattr(_core._run.TheIOManager, "wait_writable", patched_wait_writable)
s, r = await make_clogged_pipe()
async with s, r:
async with _core.open_nursery() as nursery:
nursery.start_soon(expect_closedresourceerror)
await wait_all_tasks_blocked()
# Trigger everything by waking up the sender. On ppc64el, PIPE_BUF
# is 8192 but make_clogged_pipe() ends up writing a total of
# 1048576 bytes before the pipe is full, and then a subsequent
# receive_some(10000) isn't sufficient for orig_wait_writable() to
# return for our subsequent aclose() call. It's necessary to empty
# the pipe further before this happens. So we loop here until the
# pipe is empty to make sure that the sender wakes up even in this
# case. Otherwise patched_wait_writable() never gets to the
# aclose(), so expect_closedresourceerror() never returns, the
# nursery never finishes all tasks and this test hangs.
received_data = await r.receive_some(10000)
while received_data:
received_data = await r.receive_some(10000)
# On FreeBSD, directories are readable, and we haven't found any other trick
# for making an unreadable fd, so there's no way to run this test. Fortunately
# the logic this is testing doesn't depend on the platform, so testing on
# other platforms is probably good enough.
@pytest.mark.skipif(
sys.platform.startswith("freebsd"),
reason="no way to make read() return a bizarro error on FreeBSD",
)
async def test_bizarro_OSError_from_receive() -> None:
# Make sure that if the read syscall returns some bizarro error, then we
# get a BrokenResourceError. This is incredibly unlikely; there's almost
# no way to trigger a failure here intentionally (except for EBADF, but we
# exploit that to detect file closure, so it takes a different path). So
# we set up a strange scenario where the pipe fd somehow transmutes into a
# directory fd, causing os.read to raise IsADirectoryError (yes, that's a
# real built-in exception type).
s, r = await make_pipe()
async with s, r:
dir_fd = os.open("/", os.O_DIRECTORY, 0)
try:
os.dup2(dir_fd, r.fileno())
with pytest.raises(_core.BrokenResourceError):
await r.receive_some(10)
finally:
os.close(dir_fd)
@skip_if_fbsd_pipes_broken
async def test_pipe_fully() -> None:
await check_one_way_stream(make_pipe, make_clogged_pipe)