frontends (tools/aio): add tool to run from thread, run maybe async method, or run GLib loop:

- `run_from_thread` can be used to run a method from a thread.
- `maybe_async` can be used to run a method if we are not sure if it's async or not.
- `install_glib_asyncio_iteration` run the GLib loop from asyncio one's.

rel 426
This commit is contained in:
Goffi 2023-11-01 14:00:48 +01:00
commit 1ce499a6d2

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@ -17,7 +17,7 @@
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import asyncio
from typing import Any, Coroutine
from typing import Any, Awaitable, Callable, Coroutine
from libervia.backend.core import log as logging
@ -54,3 +54,95 @@ def run_async(async_method: Coroutine | asyncio.Future) -> None:
background_tasks.add(task)
task.add_done_callback(_on_task_done)
def run_with_args(
async_method: Callable[..., Coroutine[Any, Any, Any]], *args: Any, **kwargs: Any
) -> None:
"""Schedules and tracks an asynchronous method with arguments.
This function wraps the provided asynchronous method with its arguments
and then schedules it for execution.
@param async_method: The asynchronous method to be scheduled.
@param args: Positional arguments to pass to the async_method.
@param kwargs: Keyword arguments to pass to the async_method.
"""
run_async(async_method(*args, **kwargs))
def run_from_thread(
async_method: Coroutine | asyncio.Future,
*args,
loop: asyncio.AbstractEventLoop | None = None,
**kwargs,
) -> None:
"""Schedules an asynchronous method from another thread.
@param async_method: The method to be scheduled for execution.
"""
if loop is None:
loop = asyncio.get_event_loop()
assert loop is not None
loop.call_soon_threadsafe(run_with_args, async_method, *args, **kwargs)
def maybe_async(result: Any | Awaitable[Any]) -> Awaitable[Any]:
"""
Convert the provided result into an awaitable.
@param result: the result of a function or coroutine call
@return: an awaitable object which can be awaited to get the result
"""
if asyncio.iscoroutine(result):
return result
future = asyncio.Future()
future.set_result(result)
return future
def install_glib_asyncio_iteration():
"""Import and install GLib context iteration inside our asyncio event loop.
This is used as soon as GLib is used (like GStreamer).
Inspired from Kivy's install_gobject_iteration (in ``kivy.support``), thanks to Kivy's
team.
"""
import asyncio
try:
from gi.repository import GLib
except ImportError:
raise ImportError("GLib could not be imported. Ensure it's installed.")
if hasattr(GLib, "_glib_already_installed"):
# already installed, don't do it twice.
return
GLib._glib_already_installed = True
loop = asyncio.get_event_loop()
# Create a GLib MainContext and make it the default
glib_context = GLib.MainContext.default()
# Function to iterate over the GLib main context
def _glib_iteration():
# We need to loop over the context to prevent lag
iteration_count = 0
while glib_context.pending() and iteration_count < 20:
glib_context.iteration(False)
iteration_count += 1
# If no work was done in the GLib loop, add a short delay before
# scheduling the next iteration, to prevent spinning and high CPU usage.
if iteration_count == 0:
loop.call_later(0.01, _glib_iteration)
else:
# Schedule ourselves to run again on the next asyncio loop iteration
loop.call_soon(_glib_iteration)
# Kick off the GLib iteration
loop.call_soon(_glib_iteration)