import contextvars import threading import queue as stdlib_queue import time import weakref import pytest from sniffio import current_async_library_cvar from trio._core import TrioToken, current_trio_token from .. import _core from .. import Event, CapacityLimiter, sleep from ..testing import wait_all_tasks_blocked from .._core.tests.tutil import buggy_pypy_asyncgens from .._threads import ( to_thread_run_sync, current_default_thread_limiter, from_thread_run, from_thread_run_sync, ) from .._core.tests.test_ki import ki_self async def test_do_in_trio_thread(): trio_thread = threading.current_thread() async def check_case(do_in_trio_thread, fn, expected, trio_token=None): record = [] def threadfn(): try: record.append(("start", threading.current_thread())) x = do_in_trio_thread(fn, record, trio_token=trio_token) record.append(("got", x)) except BaseException as exc: print(exc) record.append(("error", type(exc))) child_thread = threading.Thread(target=threadfn, daemon=True) child_thread.start() while child_thread.is_alive(): print("yawn") await sleep(0.01) assert record == [("start", child_thread), ("f", trio_thread), expected] token = _core.current_trio_token() def f(record): assert not _core.currently_ki_protected() record.append(("f", threading.current_thread())) return 2 await check_case(from_thread_run_sync, f, ("got", 2), trio_token=token) def f(record): assert not _core.currently_ki_protected() record.append(("f", threading.current_thread())) raise ValueError await check_case(from_thread_run_sync, f, ("error", ValueError), trio_token=token) async def f(record): assert not _core.currently_ki_protected() await _core.checkpoint() record.append(("f", threading.current_thread())) return 3 await check_case(from_thread_run, f, ("got", 3), trio_token=token) async def f(record): assert not _core.currently_ki_protected() await _core.checkpoint() record.append(("f", threading.current_thread())) raise KeyError await check_case(from_thread_run, f, ("error", KeyError), trio_token=token) async def test_do_in_trio_thread_from_trio_thread(): with pytest.raises(RuntimeError): from_thread_run_sync(lambda: None) # pragma: no branch async def foo(): # pragma: no cover pass with pytest.raises(RuntimeError): from_thread_run(foo) def test_run_in_trio_thread_ki(): # if we get a control-C during a run_in_trio_thread, then it propagates # back to the caller (slick!) record = set() async def check_run_in_trio_thread(): token = _core.current_trio_token() def trio_thread_fn(): print("in Trio thread") assert not _core.currently_ki_protected() print("ki_self") try: ki_self() finally: import sys print("finally", sys.exc_info()) async def trio_thread_afn(): trio_thread_fn() def external_thread_fn(): try: print("running") from_thread_run_sync(trio_thread_fn, trio_token=token) except KeyboardInterrupt: print("ok1") record.add("ok1") try: from_thread_run(trio_thread_afn, trio_token=token) except KeyboardInterrupt: print("ok2") record.add("ok2") thread = threading.Thread(target=external_thread_fn) thread.start() print("waiting") while thread.is_alive(): await sleep(0.01) print("waited, joining") thread.join() print("done") _core.run(check_run_in_trio_thread) assert record == {"ok1", "ok2"} def test_await_in_trio_thread_while_main_exits(): record = [] ev = Event() async def trio_fn(): record.append("sleeping") ev.set() await _core.wait_task_rescheduled(lambda _: _core.Abort.SUCCEEDED) def thread_fn(token): try: from_thread_run(trio_fn, trio_token=token) except _core.Cancelled: record.append("cancelled") async def main(): token = _core.current_trio_token() thread = threading.Thread(target=thread_fn, args=(token,)) thread.start() await ev.wait() assert record == ["sleeping"] return thread thread = _core.run(main) thread.join() assert record == ["sleeping", "cancelled"] async def test_run_in_worker_thread(): trio_thread = threading.current_thread() def f(x): return (x, threading.current_thread()) x, child_thread = await to_thread_run_sync(f, 1) assert x == 1 assert child_thread != trio_thread def g(): raise ValueError(threading.current_thread()) with pytest.raises(ValueError) as excinfo: await to_thread_run_sync(g) print(excinfo.value.args) assert excinfo.value.args[0] != trio_thread async def test_run_in_worker_thread_cancellation(): register = [None] def f(q): # Make the thread block for a controlled amount of time register[0] = "blocking" q.get() register[0] = "finished" async def child(q, cancellable): record.append("start") try: return await to_thread_run_sync(f, q, cancellable=cancellable) finally: record.append("exit") record = [] q = stdlib_queue.Queue() async with _core.open_nursery() as nursery: nursery.start_soon(child, q, True) # Give it a chance to get started. (This is important because # to_thread_run_sync does a checkpoint_if_cancelled before # blocking on the thread, and we don't want to trigger this.) await wait_all_tasks_blocked() assert record == ["start"] # Then cancel it. nursery.cancel_scope.cancel() # The task exited, but the thread didn't: assert register[0] != "finished" # Put the thread out of its misery: q.put(None) while register[0] != "finished": time.sleep(0.01) # This one can't be cancelled record = [] register[0] = None async with _core.open_nursery() as nursery: nursery.start_soon(child, q, False) await wait_all_tasks_blocked() nursery.cancel_scope.cancel() with _core.CancelScope(shield=True): for _ in range(10): await _core.checkpoint() # It's still running assert record == ["start"] q.put(None) # Now it exits # But if we cancel *before* it enters, the entry is itself a cancellation # point with _core.CancelScope() as scope: scope.cancel() await child(q, False) assert scope.cancelled_caught # Make sure that if trio.run exits, and then the thread finishes, then that's # handled gracefully. (Requires that the thread result machinery be prepared # for call_soon to raise RunFinishedError.) def test_run_in_worker_thread_abandoned(capfd, monkeypatch): monkeypatch.setattr(_core._thread_cache, "IDLE_TIMEOUT", 0.01) q1 = stdlib_queue.Queue() q2 = stdlib_queue.Queue() def thread_fn(): q1.get() q2.put(threading.current_thread()) async def main(): async def child(): await to_thread_run_sync(thread_fn, cancellable=True) async with _core.open_nursery() as nursery: nursery.start_soon(child) await wait_all_tasks_blocked() nursery.cancel_scope.cancel() _core.run(main) q1.put(None) # This makes sure: # - the thread actually ran # - that thread has finished before we check for its output thread = q2.get() while thread.is_alive(): time.sleep(0.01) # pragma: no cover # Make sure we don't have a "Exception in thread ..." dump to the console: out, err = capfd.readouterr() assert "Exception in thread" not in out assert "Exception in thread" not in err @pytest.mark.parametrize("MAX", [3, 5, 10]) @pytest.mark.parametrize("cancel", [False, True]) @pytest.mark.parametrize("use_default_limiter", [False, True]) async def test_run_in_worker_thread_limiter(MAX, cancel, use_default_limiter): # This test is a bit tricky. The goal is to make sure that if we set # limiter=CapacityLimiter(MAX), then in fact only MAX threads are ever # running at a time, even if there are more concurrent calls to # to_thread_run_sync, and even if some of those are cancelled. And # also to make sure that the default limiter actually limits. COUNT = 2 * MAX gate = threading.Event() lock = threading.Lock() if use_default_limiter: c = current_default_thread_limiter() orig_total_tokens = c.total_tokens c.total_tokens = MAX limiter_arg = None else: c = CapacityLimiter(MAX) orig_total_tokens = MAX limiter_arg = c try: # We used to use regular variables and 'nonlocal' here, but it turns # out that it's not safe to assign to closed-over variables that are # visible in multiple threads, at least as of CPython 3.10 and PyPy # 7.3: # # https://bugs.python.org/issue30744 # https://bitbucket.org/pypy/pypy/issues/2591/ # # Mutating them in-place is OK though (as long as you use proper # locking etc.). class state: pass state.ran = 0 state.high_water = 0 state.running = 0 state.parked = 0 token = _core.current_trio_token() def thread_fn(cancel_scope): print("thread_fn start") from_thread_run_sync(cancel_scope.cancel, trio_token=token) with lock: state.ran += 1 state.running += 1 state.high_water = max(state.high_water, state.running) # The Trio thread below watches this value and uses it as a # signal that all the stats calculations have finished. state.parked += 1 gate.wait() with lock: state.parked -= 1 state.running -= 1 print("thread_fn exiting") async def run_thread(event): with _core.CancelScope() as cancel_scope: await to_thread_run_sync( thread_fn, cancel_scope, limiter=limiter_arg, cancellable=cancel ) print("run_thread finished, cancelled:", cancel_scope.cancelled_caught) event.set() async with _core.open_nursery() as nursery: print("spawning") events = [] for i in range(COUNT): events.append(Event()) nursery.start_soon(run_thread, events[-1]) await wait_all_tasks_blocked() # In the cancel case, we in particular want to make sure that the # cancelled tasks don't release the semaphore. So let's wait until # at least one of them has exited, and that everything has had a # chance to settle down from this, before we check that everyone # who's supposed to be waiting is waiting: if cancel: print("waiting for first cancellation to clear") await events[0].wait() await wait_all_tasks_blocked() # Then wait until the first MAX threads are parked in gate.wait(), # and the next MAX threads are parked on the semaphore, to make # sure no-one is sneaking past, and to make sure the high_water # check below won't fail due to scheduling issues. (It could still # fail if too many threads are let through here.) while state.parked != MAX or c.statistics().tasks_waiting != MAX: await sleep(0.01) # pragma: no cover # Then release the threads gate.set() assert state.high_water == MAX if cancel: # Some threads might still be running; need to wait to them to # finish before checking that all threads ran. We can do this # using the CapacityLimiter. while c.borrowed_tokens > 0: await sleep(0.01) # pragma: no cover assert state.ran == COUNT assert state.running == 0 finally: c.total_tokens = orig_total_tokens async def test_run_in_worker_thread_custom_limiter(): # Basically just checking that we only call acquire_on_behalf_of and # release_on_behalf_of, since that's part of our documented API. record = [] class CustomLimiter: async def acquire_on_behalf_of(self, borrower): record.append("acquire") self._borrower = borrower def release_on_behalf_of(self, borrower): record.append("release") assert borrower == self._borrower await to_thread_run_sync(lambda: None, limiter=CustomLimiter()) assert record == ["acquire", "release"] async def test_run_in_worker_thread_limiter_error(): record = [] class BadCapacityLimiter: async def acquire_on_behalf_of(self, borrower): record.append("acquire") def release_on_behalf_of(self, borrower): record.append("release") raise ValueError bs = BadCapacityLimiter() with pytest.raises(ValueError) as excinfo: await to_thread_run_sync(lambda: None, limiter=bs) assert excinfo.value.__context__ is None assert record == ["acquire", "release"] record = [] # If the original function raised an error, then the semaphore error # chains with it d = {} with pytest.raises(ValueError) as excinfo: await to_thread_run_sync(lambda: d["x"], limiter=bs) assert isinstance(excinfo.value.__context__, KeyError) assert record == ["acquire", "release"] async def test_run_in_worker_thread_fail_to_spawn(monkeypatch): # Test the unlikely but possible case where trying to spawn a thread fails def bad_start(self, *args): raise RuntimeError("the engines canna take it captain") monkeypatch.setattr(_core._thread_cache.ThreadCache, "start_thread_soon", bad_start) limiter = current_default_thread_limiter() assert limiter.borrowed_tokens == 0 # We get an appropriate error, and the limiter is cleanly released with pytest.raises(RuntimeError) as excinfo: await to_thread_run_sync(lambda: None) # pragma: no cover assert "engines" in str(excinfo.value) assert limiter.borrowed_tokens == 0 async def test_trio_to_thread_run_sync_token(): # Test that to_thread_run_sync automatically injects the current trio token # into a spawned thread def thread_fn(): callee_token = from_thread_run_sync(_core.current_trio_token) return callee_token caller_token = _core.current_trio_token() callee_token = await to_thread_run_sync(thread_fn) assert callee_token == caller_token async def test_trio_to_thread_run_sync_expected_error(): # Test correct error when passed async function async def async_fn(): # pragma: no cover pass with pytest.raises(TypeError, match="expected a sync function"): await to_thread_run_sync(async_fn) trio_test_contextvar = contextvars.ContextVar("trio_test_contextvar") async def test_trio_to_thread_run_sync_contextvars(): trio_thread = threading.current_thread() trio_test_contextvar.set("main") def f(): value = trio_test_contextvar.get() sniffio_cvar_value = current_async_library_cvar.get() return (value, sniffio_cvar_value, threading.current_thread()) value, sniffio_cvar_value, child_thread = await to_thread_run_sync(f) assert value == "main" assert sniffio_cvar_value == None assert child_thread != trio_thread def g(): parent_value = trio_test_contextvar.get() trio_test_contextvar.set("worker") inner_value = trio_test_contextvar.get() sniffio_cvar_value = current_async_library_cvar.get() return ( parent_value, inner_value, sniffio_cvar_value, threading.current_thread(), ) ( parent_value, inner_value, sniffio_cvar_value, child_thread, ) = await to_thread_run_sync(g) current_value = trio_test_contextvar.get() sniffio_outer_value = current_async_library_cvar.get() assert parent_value == "main" assert inner_value == "worker" assert ( current_value == "main" ), "The contextvar value set on the worker would not propagate back to the main thread" assert sniffio_cvar_value is None assert sniffio_outer_value == "trio" async def test_trio_from_thread_run_sync(): # Test that to_thread_run_sync correctly "hands off" the trio token to # trio.from_thread.run_sync() def thread_fn(): trio_time = from_thread_run_sync(_core.current_time) return trio_time trio_time = await to_thread_run_sync(thread_fn) assert isinstance(trio_time, float) # Test correct error when passed async function async def async_fn(): # pragma: no cover pass def thread_fn(): from_thread_run_sync(async_fn) with pytest.raises(TypeError, match="expected a sync function"): await to_thread_run_sync(thread_fn) async def test_trio_from_thread_run(): # Test that to_thread_run_sync correctly "hands off" the trio token to # trio.from_thread.run() record = [] async def back_in_trio_fn(): _core.current_time() # implicitly checks that we're in trio record.append("back in trio") def thread_fn(): record.append("in thread") from_thread_run(back_in_trio_fn) await to_thread_run_sync(thread_fn) assert record == ["in thread", "back in trio"] # Test correct error when passed sync function def sync_fn(): # pragma: no cover pass with pytest.raises(TypeError, match="appears to be synchronous"): await to_thread_run_sync(from_thread_run, sync_fn) async def test_trio_from_thread_token(): # Test that to_thread_run_sync and spawned trio.from_thread.run_sync() # share the same Trio token def thread_fn(): callee_token = from_thread_run_sync(_core.current_trio_token) return callee_token caller_token = _core.current_trio_token() callee_token = await to_thread_run_sync(thread_fn) assert callee_token == caller_token async def test_trio_from_thread_token_kwarg(): # Test that to_thread_run_sync and spawned trio.from_thread.run_sync() can # use an explicitly defined token def thread_fn(token): callee_token = from_thread_run_sync(_core.current_trio_token, trio_token=token) return callee_token caller_token = _core.current_trio_token() callee_token = await to_thread_run_sync(thread_fn, caller_token) assert callee_token == caller_token async def test_from_thread_no_token(): # Test that a "raw call" to trio.from_thread.run() fails because no token # has been provided with pytest.raises(RuntimeError): from_thread_run_sync(_core.current_time) async def test_trio_from_thread_run_sync_contextvars(): trio_test_contextvar.set("main") def thread_fn(): thread_parent_value = trio_test_contextvar.get() trio_test_contextvar.set("worker") thread_current_value = trio_test_contextvar.get() sniffio_cvar_thread_pre_value = current_async_library_cvar.get() def back_in_main(): back_parent_value = trio_test_contextvar.get() trio_test_contextvar.set("back_in_main") back_current_value = trio_test_contextvar.get() sniffio_cvar_back_value = current_async_library_cvar.get() return back_parent_value, back_current_value, sniffio_cvar_back_value ( back_parent_value, back_current_value, sniffio_cvar_back_value, ) = from_thread_run_sync(back_in_main) thread_after_value = trio_test_contextvar.get() sniffio_cvar_thread_after_value = current_async_library_cvar.get() return ( thread_parent_value, thread_current_value, thread_after_value, sniffio_cvar_thread_pre_value, sniffio_cvar_thread_after_value, back_parent_value, back_current_value, sniffio_cvar_back_value, ) ( thread_parent_value, thread_current_value, thread_after_value, sniffio_cvar_thread_pre_value, sniffio_cvar_thread_after_value, back_parent_value, back_current_value, sniffio_cvar_back_value, ) = await to_thread_run_sync(thread_fn) current_value = trio_test_contextvar.get() sniffio_cvar_out_value = current_async_library_cvar.get() assert current_value == thread_parent_value == "main" assert thread_current_value == back_parent_value == thread_after_value == "worker" assert back_current_value == "back_in_main" assert sniffio_cvar_out_value == sniffio_cvar_back_value == "trio" assert sniffio_cvar_thread_pre_value == sniffio_cvar_thread_after_value == None async def test_trio_from_thread_run_contextvars(): trio_test_contextvar.set("main") def thread_fn(): thread_parent_value = trio_test_contextvar.get() trio_test_contextvar.set("worker") thread_current_value = trio_test_contextvar.get() sniffio_cvar_thread_pre_value = current_async_library_cvar.get() async def async_back_in_main(): back_parent_value = trio_test_contextvar.get() trio_test_contextvar.set("back_in_main") back_current_value = trio_test_contextvar.get() sniffio_cvar_back_value = current_async_library_cvar.get() return back_parent_value, back_current_value, sniffio_cvar_back_value ( back_parent_value, back_current_value, sniffio_cvar_back_value, ) = from_thread_run(async_back_in_main) thread_after_value = trio_test_contextvar.get() sniffio_cvar_thread_after_value = current_async_library_cvar.get() return ( thread_parent_value, thread_current_value, thread_after_value, sniffio_cvar_thread_pre_value, sniffio_cvar_thread_after_value, back_parent_value, back_current_value, sniffio_cvar_back_value, ) ( thread_parent_value, thread_current_value, thread_after_value, sniffio_cvar_thread_pre_value, sniffio_cvar_thread_after_value, back_parent_value, back_current_value, sniffio_cvar_back_value, ) = await to_thread_run_sync(thread_fn) current_value = trio_test_contextvar.get() assert current_value == thread_parent_value == "main" assert thread_current_value == back_parent_value == thread_after_value == "worker" assert back_current_value == "back_in_main" assert sniffio_cvar_thread_pre_value == sniffio_cvar_thread_after_value == None assert sniffio_cvar_back_value == "trio" def test_run_fn_as_system_task_catched_badly_typed_token(): with pytest.raises(RuntimeError): from_thread_run_sync(_core.current_time, trio_token="Not TrioTokentype") async def test_from_thread_inside_trio_thread(): def not_called(): # pragma: no cover assert False trio_token = _core.current_trio_token() with pytest.raises(RuntimeError): from_thread_run_sync(not_called, trio_token=trio_token) @pytest.mark.skipif(buggy_pypy_asyncgens, reason="pypy 7.2.0 is buggy") def test_from_thread_run_during_shutdown(): save = [] record = [] async def agen(): try: yield finally: with pytest.raises(_core.RunFinishedError), _core.CancelScope(shield=True): await to_thread_run_sync(from_thread_run, sleep, 0) record.append("ok") async def main(): save.append(agen()) await save[-1].asend(None) _core.run(main) assert record == ["ok"] async def test_trio_token_weak_referenceable(): token = current_trio_token() assert isinstance(token, TrioToken) weak_reference = weakref.ref(token) assert token is weak_reference() async def test_unsafe_cancellable_kwarg(): # This is a stand in for a numpy ndarray or other objects # that (maybe surprisingly) lack a notion of truthiness class BadBool: def __bool__(self): raise NotImplementedError with pytest.raises(NotImplementedError): await to_thread_run_sync(int, cancellable=BadBool())