Add --task-impl option

README.md

@@ -101,6 +101,9 @@ Options:
   --loop [auto|asyncio|rloop|uvloop]
                                   Event loop implementation  [env var:
                                   GRANIAN_LOOP; default: (auto)]
+  --task-impl [auto|rust|asyncio]
+                                  Async task implementation to use  [env var:
+                                  GRANIAN_TASK_IMPL; default: (auto)]
   --backlog INTEGER RANGE         Maximum number of connections to hold in
                                   backlog (globally)  [env var:
                                   GRANIAN_BACKLOG; default: 1024; x>=128]

granian/_futures.py

@@ -25,10 +25,17 @@ def __init__(self, loop, ctx, cb, aio_tenter, aio_texit):
         self._schedule_fn = _cbsched_schedule(loop, ctx, self._run, cb)
 
 
-def _new_cbscheduler(loop, cb):
-    return _CBScheduler(
-        loop, contextvars.copy_context(), cb, partial(_aio_taskenter, loop), partial(_aio_taskleave, loop)
-    )
+class _CBSchedulerAIO(_BaseCBScheduler):
+    __slots__ = []
+
+    def __init__(self, loop, ctx, cb, aio_tenter, aio_texit):
+        super().__init__()
+        self._schedule_fn = _cbsched_schedule(loop, ctx, loop.create_task, cb)
+
+
+def _new_cbscheduler(loop, cb, impl_asyncio=False):
+    _cls = _CBSchedulerAIO if impl_asyncio else _CBScheduler
+    return _cls(loop, contextvars.copy_context(), cb, partial(_aio_taskenter, loop), partial(_aio_taskleave, loop))
 
 
 def _cbsched_schedule(loop, ctx, run, cb):

granian/_imports.py

@@ -1,3 +1,8 @@
+try:
+    import anyio
+except ImportError:
+    anyio = None
+
 try:
     import setproctitle
 except ImportError:

granian/cli.py

@@ -5,7 +5,7 @@
 
 import click
 
-from .constants import HTTPModes, Interfaces, Loops, ThreadModes
+from .constants import HTTPModes, Interfaces, Loops, TaskImpl, ThreadModes
 from .errors import FatalError
 from .http import HTTP1Settings, HTTP2Settings
 from .log import LogLevels
@@ -77,6 +77,12 @@ def option(*param_decls: str, cls: Optional[Type[click.Option]] = None, **attrs:
     help='Threading mode to use',
 )
 @option('--loop', type=EnumType(Loops), default=Loops.auto, help='Event loop implementation')
+@option(
+    '--task-impl',
+    type=EnumType(TaskImpl),
+    default=TaskImpl.auto,
+    help='Async task implementation to use',
+)
 @option(
     '--backlog',
     type=click.IntRange(128),
@@ -261,6 +267,7 @@ def cli(
     blocking_threads: Optional[int],
     threading_mode: ThreadModes,
     loop: Loops,
+    task_impl: TaskImpl,
     backlog: int,
     backpressure: Optional[int],
     http1_buffer_size: int,
@@ -316,6 +323,7 @@ def cli(
         blocking_threads=blocking_threads,
         threading_mode=threading_mode,
         loop=loop,
+        task_impl=task_impl,
         http=http,
         websockets=websockets,
         backlog=backlog,

granian/constants.py

@@ -29,3 +29,9 @@ class Loops(StrEnum):
     asyncio = 'asyncio'
     rloop = 'rloop'
     uvloop = 'uvloop'
+
+
+class TaskImpl(StrEnum):
+    auto = 'auto'
+    rust = 'rust'
+    asyncio = 'asyncio'

granian/server.py

@@ -14,11 +14,11 @@
 
 from ._futures import _future_watcher_wrapper, _new_cbscheduler
 from ._granian import ASGIWorker, RSGIWorker, WSGIWorker
-from ._imports import setproctitle, watchfiles
+from ._imports import anyio, setproctitle, watchfiles
 from ._internal import load_target
 from ._signals import set_main_signals
 from .asgi import LifespanProtocol, _callback_wrapper as _asgi_call_wrap
-from .constants import HTTPModes, Interfaces, Loops, ThreadModes
+from .constants import HTTPModes, Interfaces, Loops, TaskImpl, ThreadModes
 from .errors import ConfigurationError, PidFileError
 from .http import HTTP1Settings, HTTP2Settings
 from .log import DEFAULT_ACCESSLOG_FMT, LogLevels, configure_logging, logger
@@ -81,6 +81,7 @@ def __init__(
         blocking_threads: Optional[int] = None,
         threading_mode: ThreadModes = ThreadModes.workers,
         loop: Loops = Loops.auto,
+        task_impl: TaskImpl = TaskImpl.auto,
         http: HTTPModes = HTTPModes.auto,
         websockets: bool = True,
         backlog: int = 1024,
@@ -118,6 +119,7 @@ def __init__(
         self.threads = max(1, threads)
         self.threading_mode = threading_mode
         self.loop = loop
+        self.task_impl = task_impl
         self.http = http
         self.websockets = websockets
         self.backlog = max(128, backlog)
@@ -188,6 +190,7 @@ def _spawn_asgi_worker(
         blocking_threads: int,
         backpressure: int,
         threading_mode: ThreadModes,
+        task_impl: TaskImpl,
         http_mode: HTTPModes,
         http1_settings: Optional[HTTP1Settings],
         http2_settings: Optional[HTTP2Settings],
@@ -225,7 +228,9 @@ def _spawn_asgi_worker(
             *ssl_ctx,
         )
         serve = getattr(worker, {ThreadModes.runtime: 'serve_rth', ThreadModes.workers: 'serve_wth'}[threading_mode])
-        scheduler = _new_cbscheduler(loop, _future_watcher_wrapper(wcallback))
+        scheduler = _new_cbscheduler(
+            loop, _future_watcher_wrapper(wcallback), impl_asyncio=task_impl == TaskImpl.asyncio
+        )
         serve(scheduler, loop, shutdown_event)
 
     @staticmethod
@@ -239,6 +244,7 @@ def _spawn_asgi_lifespan_worker(
         blocking_threads: int,
         backpressure: int,
         threading_mode: ThreadModes,
+        task_impl: TaskImpl,
         http_mode: HTTPModes,
         http1_settings: Optional[HTTP1Settings],
         http2_settings: Optional[HTTP2Settings],
@@ -283,7 +289,9 @@ def _spawn_asgi_lifespan_worker(
             *ssl_ctx,
         )
         serve = getattr(worker, {ThreadModes.runtime: 'serve_rth', ThreadModes.workers: 'serve_wth'}[threading_mode])
-        scheduler = _new_cbscheduler(loop, _future_watcher_wrapper(wcallback))
+        scheduler = _new_cbscheduler(
+            loop, _future_watcher_wrapper(wcallback), impl_asyncio=task_impl == TaskImpl.asyncio
+        )
         serve(scheduler, loop, shutdown_event)
         loop.run_until_complete(lifespan_handler.shutdown())
 
@@ -298,6 +306,7 @@ def _spawn_rsgi_worker(
         blocking_threads: int,
         backpressure: int,
         threading_mode: ThreadModes,
+        task_impl: TaskImpl,
         http_mode: HTTPModes,
         http1_settings: Optional[HTTP1Settings],
         http2_settings: Optional[HTTP2Settings],
@@ -343,7 +352,9 @@ def _spawn_rsgi_worker(
             *ssl_ctx,
         )
         serve = getattr(worker, {ThreadModes.runtime: 'serve_rth', ThreadModes.workers: 'serve_wth'}[threading_mode])
-        scheduler = _new_cbscheduler(loop, _future_watcher_wrapper(callback))
+        scheduler = _new_cbscheduler(
+            loop, _future_watcher_wrapper(callback), impl_asyncio=task_impl == TaskImpl.asyncio
+        )
         serve(scheduler, loop, shutdown_event)
         callback_del(loop)
 
@@ -358,6 +369,7 @@ def _spawn_wsgi_worker(
         blocking_threads: int,
         backpressure: int,
         threading_mode: ThreadModes,
+        task_impl: TaskImpl,
         http_mode: HTTPModes,
         http1_settings: Optional[HTTP1Settings],
         http2_settings: Optional[HTTP2Settings],
@@ -385,7 +397,9 @@ def _spawn_wsgi_worker(
             worker_id, sfd, threads, blocking_threads, backpressure, http_mode, http1_settings, http2_settings, *ssl_ctx
         )
         serve = getattr(worker, {ThreadModes.runtime: 'serve_rth', ThreadModes.workers: 'serve_wth'}[threading_mode])
-        scheduler = _new_cbscheduler(loop, _wsgi_call_wrap(callback, scope_opts, log_access_fmt))
+        scheduler = _new_cbscheduler(
+            loop, _wsgi_call_wrap(callback, scope_opts, log_access_fmt), impl_asyncio=task_impl == TaskImpl.asyncio
+        )
         serve(scheduler, loop, shutdown_event)
         shutdown_event.qs.wait()
 
@@ -416,6 +430,7 @@ def _spawn_proc(self, idx, target, callback_loader, socket_loader) -> Worker:
                 self.blocking_threads,
                 self.backpressure,
                 self.threading_mode,
+                self.task_impl,
                 self.http,
                 self.http1_settings,
                 self.http2_settings,
@@ -713,5 +728,8 @@ def serve(
                 logger.error('Workers lifetime cannot be less than 60 seconds')
                 raise ConfigurationError('workers_lifetime')
 
+        if self.task_impl == TaskImpl.auto:
+            self.task_impl = TaskImpl.asyncio if anyio is not None else TaskImpl.rust
+
         serve_method = self._serve_with_reloader if self.reload_on_changes else self._serve
         serve_method(spawn_target, target_loader)

pyproject.toml

@@ -98,7 +98,7 @@ extend-ignore = [
     'S110', # except pass is fine
 ]
 flake8-quotes = { inline-quotes = 'single', multiline-quotes = 'double' }
-mccabe = { max-complexity = 13 }
+mccabe = { max-complexity = 14 }
 
 [tool.ruff.format]
 quote-style = 'single'