Add a basic no-raise-on lag test

breceiver_internals
Tyler Goodlet 2023-01-30 12:26:07 -05:00
parent 8637778739
commit efb8bec828
1 changed files with 54 additions and 2 deletions

View File

@ -12,7 +12,10 @@ import pytest
import trio import trio
from trio.lowlevel import current_task from trio.lowlevel import current_task
import tractor import tractor
from tractor.trionics import broadcast_receiver, Lagged from tractor.trionics import (
broadcast_receiver,
Lagged,
)
@tractor.context @tractor.context
@ -211,7 +214,8 @@ def test_faster_task_to_recv_is_cancelled_by_slower(
arb_addr, arb_addr,
start_method, start_method,
): ):
'''Ensure that if a faster task consuming from a stream is cancelled '''
Ensure that if a faster task consuming from a stream is cancelled
the slower task can continue to receive all expected values. the slower task can continue to receive all expected values.
''' '''
@ -460,3 +464,51 @@ def test_first_recver_is_cancelled():
assert value == 1 assert value == 1
trio.run(main) trio.run(main)
def test_no_raise_on_lag():
'''
Run a simple 2-task broadcast where one task is slow but configured
so that it does not raise `Lagged` on overruns using
`raise_on_lasg=False` and verify that the task does not raise.
'''
size = 100
tx, rx = trio.open_memory_channel(size)
brx = broadcast_receiver(rx, size)
async def slow():
async with brx.subscribe(
raise_on_lag=False,
) as br:
async for msg in br:
print(f'slow task got: {msg}')
await trio.sleep(0.1)
async def fast():
async with brx.subscribe() as br:
async for msg in br:
print(f'fast task got: {msg}')
async def main():
async with (
tractor.open_root_actor(
# NOTE: so we see the warning msg emitted by the bcaster
# internals when the no raise flag is set.
loglevel='warning',
),
trio.open_nursery() as n,
):
n.start_soon(slow)
n.start_soon(fast)
for i in range(1000):
await tx.send(i)
# simulate user nailing ctl-c after realizing
# there's a lag in the slow task.
await trio.sleep(1)
raise KeyboardInterrupt
with pytest.raises(KeyboardInterrupt):
trio.run(main)