In run_process moved deliver_cancel exception handling to the caller code

newsfragments/1532.misc.rst

@@ -0,0 +1 @@
+In `run_process` moved `deliver_cancel` exception handling to the caller code.

trio/_subprocess.py

@@ -1,5 +1,6 @@
 import os
 import subprocess
+import logging
 import sys
 from typing import Optional
 from functools import partial
@@ -381,28 +382,20 @@ async def open_process(
 
 
 async def _windows_deliver_cancel(p):
- try:
- p.terminate()
- except OSError as exc:
- warnings.warn(RuntimeWarning(f"TerminateProcess on {p!r} failed with: {exc!r}"))
+ p.terminate()
 
 
 async def _posix_deliver_cancel(p):
- try:
- p.terminate()
- await trio.sleep(5)
- warnings.warn(
- RuntimeWarning(
- f"process {p!r} ignored SIGTERM for 5 seconds. "
- f"(Maybe you should pass a custom deliver_cancel?) "
- f"Trying SIGKILL."
- )
- )
- p.kill()
- except OSError as exc:
- warnings.warn(
- RuntimeWarning(f"tried to kill process {p!r}, but failed with: {exc!r}")
+ p.terminate()
+ await trio.sleep(5)
+ warnings.warn(
+ RuntimeWarning(
+ f"process {p!r} ignored SIGTERM for 5 seconds. "
+ f"(Maybe you should pass a custom deliver_cancel?) "
+ f"Trying SIGKILL."
  )
+ )
+ p.kill()
 
 
 async def run_process(
@@ -592,41 +585,48 @@ async def my_deliver_cancel(process):
  stdout_chunks = []
  stderr_chunks = []
 
- async with await open_process(command, **options) as proc:
-
- async def feed_input():
- async with proc.stdin:
- try:
- await proc.stdin.send_all(input)
- except trio.BrokenResourceError:
- pass
-
- async def read_output(stream, chunks):
- async with stream:
- async for chunk in stream:
- chunks.append(chunk)
-
- async with trio.open_nursery() as nursery:
- if proc.stdin is not None:
- nursery.start_soon(feed_input)
- if proc.stdout is not None:
- nursery.start_soon(read_output, proc.stdout, stdout_chunks)
- if proc.stderr is not None:
- nursery.start_soon(read_output, proc.stderr, stderr_chunks)
+ proc = await open_process(command, **options)
+
+ async def feed_input():
+ async with proc.stdin:
  try:
- await proc.wait()
- except trio.Cancelled:
- with trio.CancelScope(shield=True):
- killer_cscope = trio.CancelScope(shield=True)
+ await proc.stdin.send_all(input)
+ except trio.BrokenResourceError:
+ pass
 
- async def killer():
- with killer_cscope:
+ async def read_output(stream, chunks):
+ async with stream:
+ async for chunk in stream:
+ chunks.append(chunk)
+
+ async with trio.open_nursery() as nursery:
+ if proc.stdin is not None:
+ nursery.start_soon(feed_input)
+ if proc.stdout is not None:
+ nursery.start_soon(read_output, proc.stdout, stdout_chunks)
+ if proc.stderr is not None:
+ nursery.start_soon(read_output, proc.stderr, stderr_chunks)
+ try:
+ await proc.wait()
+ except trio.Cancelled:
+ with trio.CancelScope(shield=True):
+ killer_cscope = trio.CancelScope(shield=True)
+
+ async def killer():
+ with killer_cscope:
+ try:
  await deliver_cancel(proc)
-
- nursery.start_soon(killer)
- await proc.wait()
- killer_cscope.cancel()
- raise
+ except BaseException as exc:
+ LOGGER = logging.getLogger("trio.run_process")
+ LOGGER.exception(
+ f"tried to kill process {proc!r}, but failed with: {exc!r}"
+ )
+ raise
+
+ nursery.start_soon(killer)
+ await proc.wait()
+ killer_cscope.cancel()
+ raise
 
  stdout = b"".join(stdout_chunks) if proc.stdout is not None else None
  stderr = b"".join(stderr_chunks) if proc.stderr is not None else None

trio/tests/test_subprocess.py

@@ -455,7 +455,7 @@ async def custom_deliver_cancel(proc):
  assert custom_deliver_cancel_called
 
 
-async def test_warn_on_failed_cancel_terminate(monkeypatch):
+async def test_log_on_failed_cancel_terminate(monkeypatch):
  original_terminate = Process.terminate
 
  def broken_terminate(self):
@@ -464,7 +464,7 @@ def broken_terminate(self):
 
  monkeypatch.setattr(Process, "terminate", broken_terminate)
 
- with pytest.warns(RuntimeWarning, match=".*whoops.*"):
+ with pytest.raises(OSError, match=".*whoops.*"):
  async with _core.open_nursery() as nursery:
  nursery.start_soon(run_process, SLEEP(9999))
  await wait_all_tasks_blocked()