Merge pull request #124 from oremanj/sniffio-via-tlocal

Modernize sniffio integration

Author: oremanj

.github/workflows/ci.yml

@@ -56,7 +56,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python: ['pypy-3.7', 'pypy-3.8', 'pypy-3.9', '3.7', '3.8', '3.9', '3.10', '3.11', '3.12-dev', 'pypy-3.8-nightly', 'pypy-3.9-nightly']
+        python: ['pypy-3.7', 'pypy-3.8', 'pypy-3.9', '3.7', '3.8', '3.9', '3.10', '3.11', 'pypy-3.8-nightly', 'pypy-3.9-nightly']
         check_formatting: ['0']
         extra_name: ['']
         include:

.readthedocs.yml

@@ -5,8 +5,12 @@ formats:
   - htmlzip
   - epub
 
+build:
+  os: "ubuntu-22.04"
+  tools:
+    python: "3.11"
+
 python:
-  version: 3.7
   install:
     - requirements: docs-requirements.txt
 

docs/source/conf.py

@@ -104,7 +104,7 @@
 #
 # This is also used if you do content translation via gettext catalogs.
 # Usually you set "language" from the command line for these cases.
-language = None
+language = "en"
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.

newsfragments/123.misc.rst

@@ -0,0 +1,5 @@
+trio-asyncio now indicates its presence to `sniffio` using the
+``sniffio.thread_local`` interface that is preferred since sniffio
+v1.3.0. This should be less likely than the previous approach to cause
+:func:`sniffio.current_async_library` to return incorrect results due
+to unintended inheritance of contextvars.

setup.py

@@ -65,7 +65,7 @@
     install_requires=[
         "trio >= 0.22.0",
         "outcome",
-        "sniffio",
+        "sniffio >= 1.3.0",
         "exceptiongroup >= 1.0.0; python_version < '3.11'",
     ],
     # This means, just install *everything* you see under trio/, even if it

trio_asyncio/_base.py

@@ -4,7 +4,6 @@
 import trio
 import heapq
 import signal
-import sniffio
 import asyncio
 import warnings
 import concurrent.futures
@@ -13,6 +12,7 @@
 from ._util import run_aio_future
 
 from selectors import _BaseSelectorImpl, EVENT_READ, EVENT_WRITE
+from sniffio import thread_local as sniffio_library
 
 try:
     from trio.lowlevel import wait_for_child
@@ -218,15 +218,11 @@ async def run_aio_coroutine(self, coro):
         """
         try:
             self._check_closed()
-            t = sniffio.current_async_library_cvar.set("asyncio")
             fut = asyncio.ensure_future(coro, loop=self)
         except BaseException:
             coro.close()  # avoid unawaited coroutine error
             raise
-        try:
-            return await run_aio_future(fut)
-        finally:
-            sniffio.current_async_library_cvar.reset(t)
+        return await run_aio_future(fut)
 
     def trio_as_future(self, proc, *args):
         """Start a new Trio task to run ``await proc(*args)`` asynchronously.
@@ -641,7 +637,6 @@ async def _main_loop(self, task_status=trio.TASK_STATUS_IGNORED):
 
         self._stopped = trio.Event()
         task_status.started()
-        sniffio.current_async_library_cvar.set("asyncio")
 
         try:
             # The shield here ensures that if the context surrounding
@@ -701,10 +696,16 @@ async def _main_loop_one(self, no_wait=False):
         # Don't go through the expensive nursery dance
         # if this is a sync function.
         if isinstance(obj, AsyncHandle):
+            # AsyncHandle is only used to run Trio tasks, so no need to set the
+            # sniffio library
             obj._context.run(self._nursery.start_soon, obj._run, name=obj._callback)
             await obj._started.wait()
         else:
-            obj._run()
+            prev_library, sniffio_library.name = sniffio_library.name, "asyncio"
+            try:
+                obj._run()
+            finally:
+                sniffio_library.name = prev_library
 
     async def _main_loop_exit(self):
         """Finalize the loop. It may not be re-entered."""

trio_asyncio/_handles.py

@@ -2,7 +2,6 @@
 import trio
 import types
 import asyncio
-import sniffio
 from asyncio.format_helpers import _format_callback, _get_function_source
 
 if sys.version_info < (3, 11):
@@ -139,7 +138,6 @@ def propagate_cancel(f):
                     self.cancel()
 
     async def _run(self):
-        sniffio.current_async_library_cvar.set("trio")
         self._started.set()
         if self._cancelled:
             return

trio_asyncio/_util.py

@@ -5,7 +5,6 @@
 import asyncio
 import sys
 import outcome
-import sniffio
 
 
 async def run_aio_future(future):
@@ -69,7 +68,6 @@ async def run_aio_generator(loop, async_generator):
     current_read = None
 
     async def consume_next():
-        t = sniffio.current_async_library_cvar.set("asyncio")
         try:
             item = await async_generator.__anext__()
             result = outcome.Value(value=item)
@@ -80,8 +78,6 @@ async def consume_next():
             return
         except Exception as e:
             result = outcome.Error(error=e)
-        finally:
-            sniffio.current_async_library_cvar.reset(t)
 
         trio.lowlevel.reschedule(task, result)