circuitpython/tests/extmod/uasyncio_threadsafeflag.py
Ned Konz 5543b2a9cc extmod/uasyncio: Add clear method to ThreadSafeFlag.
This is useful in situations where the ThreadSafeFlag is reused and needs
to be cleared of any previous, unwanted event.

For example, clear the flag at the start of an operation, trigger the
operation (eg an I2C write), then (a)wait for an external event to set the
flag (eg a pin IRQ).  Further events may trigger the flag again but these
are unwanted and should be cleared before the next cycle starts.
2022-08-12 17:06:28 +10:00

100 lines
1.9 KiB
Python

# Test Event class
try:
import uasyncio as asyncio
except ImportError:
print("SKIP")
raise SystemExit
import micropython
try:
micropython.schedule
except AttributeError:
print("SKIP")
raise SystemExit
try:
# Unix port can't select/poll on user-defined types.
import uselect as select
poller = select.poll()
poller.register(asyncio.ThreadSafeFlag())
except TypeError:
print("SKIP")
raise SystemExit
async def task(id, flag):
print("task", id)
await flag.wait()
print("task", id, "done")
def set_from_schedule(flag):
print("schedule")
flag.set()
print("schedule done")
async def main():
flag = asyncio.ThreadSafeFlag()
# Set the flag from within the loop.
t = asyncio.create_task(task(1, flag))
print("yield")
await asyncio.sleep(0)
print("set event")
flag.set()
print("yield")
await asyncio.sleep(0)
print("wait task")
await t
# Set the flag from scheduler context.
print("----")
t = asyncio.create_task(task(2, flag))
print("yield")
await asyncio.sleep(0)
print("set event")
micropython.schedule(set_from_schedule, flag)
print("yield")
await asyncio.sleep(0)
print("wait task")
await t
# Flag already set.
print("----")
print("set event")
flag.set()
t = asyncio.create_task(task(3, flag))
print("yield")
await asyncio.sleep(0)
print("wait task")
await t
# Flag set, cleared, and set again.
print("----")
print("set event")
flag.set()
print("yield")
await asyncio.sleep(0)
print("clear event")
flag.clear()
print("yield")
await asyncio.sleep(0)
t = asyncio.create_task(task(4, flag))
print("yield")
await asyncio.sleep(0)
print("set event")
flag.set()
print("yield")
await asyncio.sleep(0)
print("wait task")
await t
asyncio.run(main())