a _D@sddlZddlZddlZddlmZmZddlmZmZddl m Z m Z m Z m Z mZddl Z e jrrddl mZmZgdZGdddeZGd d d eZGd d d eZGd ddeZGdddeZGdddeZGdddeZdS)N)genioloop)Future"future_set_result_unless_cancelled)UnionOptionalTypeAny Awaitable)DequeSet) ConditionEvent SemaphoreBoundedSemaphoreLockc@s,eZdZdZddddZddddZdS)_TimeoutGarbageCollectorzBase class for objects that periodically clean up timed-out waiters. Avoids memory leak in a common pattern like: while True: yield condition.wait(short_timeout) print('looping....') NreturncCst|_d|_dS)Nr) collectionsdeque_waiters _timeoutsselfr,lib/python3.9/site-packages/tornado/locks.py__init__)s z!_TimeoutGarbageCollector.__init__cCs:|jd7_|jdkr6d|_tdd|jD|_dS)Ndrcss|]}|s|VqdSN)done).0wrrr 2z<_TimeoutGarbageCollector._garbage_collect..)rrrrrrrr_garbage_collect-s z)_TimeoutGarbageCollector._garbage_collect)__name__ __module__ __qualname____doc__rr&rrrrrs rcsxeZdZdZddfdd ZedddZdeee e j fe e dd d Zdedd d dZddddZZS)r aA condition allows one or more coroutines to wait until notified. Like a standard `threading.Condition`, but does not need an underlying lock that is acquired and released. With a `Condition`, coroutines can wait to be notified by other coroutines: .. testcode:: from tornado import gen from tornado.ioloop import IOLoop from tornado.locks import Condition condition = Condition() async def waiter(): print("I'll wait right here") await condition.wait() print("I'm done waiting") async def notifier(): print("About to notify") condition.notify() print("Done notifying") async def runner(): # Wait for waiter() and notifier() in parallel await gen.multi([waiter(), notifier()]) IOLoop.current().run_sync(runner) .. testoutput:: I'll wait right here About to notify Done notifying I'm done waiting `wait` takes an optional ``timeout`` argument, which is either an absolute timestamp:: io_loop = IOLoop.current() # Wait up to 1 second for a notification. await condition.wait(timeout=io_loop.time() + 1) ...or a `datetime.timedelta` for a timeout relative to the current time:: # Wait up to 1 second. await condition.wait(timeout=datetime.timedelta(seconds=1)) The method returns False if there's no notification before the deadline. .. versionchanged:: 5.0 Previously, waiters could be notified synchronously from within `notify`. Now, the notification will always be received on the next iteration of the `.IOLoop`. Nrcsttj|_dSr )superrrIOLoopcurrentio_loopr __class__rrrqs zCondition.__init__cCs.d|jjf}|jr&|dt|j7}|dS)Nz<%sz waiters[%s]>)r0r'rlen)rresultrrr__repr__uszCondition.__repr__timeoutrcsXtj|rTddfdd }tj||fddS)zWait for `.notify`. Returns a `.Future` that resolves ``True`` if the condition is notified, or ``False`` after a timeout. NrcsstddSNF)r!rr&rrwaiterrr on_timeouts z"Condition.wait..on_timeoutcs Sr Zremove_timeout_r.timeout_handlerrr%z Condition.wait..)rrappendrr,r- add_timeoutadd_done_callbackrr6r:rr.rr?r9rwait{s   zCondition.waitr)nrcCsLg}|r4|jr4|j}|s|d8}||q|D]}t|dq8dS)zWake ``n`` waiters.rTN)rpopleftr!rAr)rrGwaitersr9rrrnotifys   zCondition.notifycCs|t|jdS)zWake all waiters.N)rJr2rrrrr notify_allszCondition.notify_all)N)r)r'r(r)r*rstrr4rrfloatdatetime timedeltar boolrFintrJrK __classcell__rrr/rr 5s;  r c@szeZdZdZddddZedddZeddd Zddd d Z ddd d Z de e e ejfeddddZdS)raAn event blocks coroutines until its internal flag is set to True. Similar to `threading.Event`. A coroutine can wait for an event to be set. Once it is set, calls to ``yield event.wait()`` will not block unless the event has been cleared: .. testcode:: from tornado import gen from tornado.ioloop import IOLoop from tornado.locks import Event event = Event() async def waiter(): print("Waiting for event") await event.wait() print("Not waiting this time") await event.wait() print("Done") async def setter(): print("About to set the event") event.set() async def runner(): await gen.multi([waiter(), setter()]) IOLoop.current().run_sync(runner) .. testoutput:: Waiting for event About to set the event Not waiting this time Done NrcCsd|_t|_dSr7)_valuesetrrrrrrszEvent.__init__cCsd|jj|rdndfS)Nz<%s %s>rTclear)r0r'is_setrrrrr4szEvent.__repr__cCs|jS)z-Return ``True`` if the internal flag is true.rSrrrrrVsz Event.is_setcCs.|js*d|_|jD]}|s|dqdS)zSet the internal flag to ``True``. All waiters are awakened. Calling `.wait` once the flag is set will not block. TN)rSrr! set_result)rfutrrrrTs  z Event.setcCs d|_dS)zkReset the internal flag to ``False``. Calls to `.wait` will block until `.set` is called. FNrWrrrrrUsz Event.clearr5csjtjrdSjfdd|durDSt|}|fdd|SdS)zBlock until the internal flag is true. Returns an awaitable, which raises `tornado.util.TimeoutError` after a timeout. Ncs j|Sr )rremoverYrrrr@r%zEvent.wait..cssSdSr )r!Zcancel)Ztfr[rrr@r%)rrSrXraddrCrZ with_timeout)rr6Z timeout_futr)rYrrrFs    z Event.wait)N)r'r(r)r*rrLr4rPrVrTrUrrrMrNrOr rFrrrrrs' rc@sLeZdZdZeddddZddddZd eeee j dd d d Z dS) _ReleasingContextManagerzReleases a Lock or Semaphore at the end of a "with" statement. with (yield semaphore.acquire()): pass # Now semaphore.release() has been called. N)objrcCs ||_dSr )_obj)rr^rrrrsz!_ReleasingContextManager.__init__rcCsdSr rrrrr __enter__sz"_ReleasingContextManager.__enter__Optional[Type[BaseException]])exc_typeexc_valexc_tbrcCs|jdSr )r_release)rrbrcrdrrr__exit__sz!_ReleasingContextManager.__exit__) r'r(r)r*r rr`r BaseExceptiontypes TracebackTyperfrrrrr]sr]cseZdZdZdeddfdd Zedfdd Zddd d Zde e e e j feed d dZddddZde ee ejddddZddddZde ee ejddddZZS)raS A lock that can be acquired a fixed number of times before blocking. A Semaphore manages a counter representing the number of `.release` calls minus the number of `.acquire` calls, plus an initial value. The `.acquire` method blocks if necessary until it can return without making the counter negative. Semaphores limit access to a shared resource. To allow access for two workers at a time: .. testsetup:: semaphore from collections import deque from tornado import gen from tornado.ioloop import IOLoop from tornado.concurrent import Future # Ensure reliable doctest output: resolve Futures one at a time. futures_q = deque([Future() for _ in range(3)]) async def simulator(futures): for f in futures: # simulate the asynchronous passage of time await gen.sleep(0) await gen.sleep(0) f.set_result(None) IOLoop.current().add_callback(simulator, list(futures_q)) def use_some_resource(): return futures_q.popleft() .. testcode:: semaphore from tornado import gen from tornado.ioloop import IOLoop from tornado.locks import Semaphore sem = Semaphore(2) async def worker(worker_id): await sem.acquire() try: print("Worker %d is working" % worker_id) await use_some_resource() finally: print("Worker %d is done" % worker_id) sem.release() async def runner(): # Join all workers. await gen.multi([worker(i) for i in range(3)]) IOLoop.current().run_sync(runner) .. testoutput:: semaphore Worker 0 is working Worker 1 is working Worker 0 is done Worker 2 is working Worker 1 is done Worker 2 is done Workers 0 and 1 are allowed to run concurrently, but worker 2 waits until the semaphore has been released once, by worker 0. The semaphore can be used as an async context manager:: async def worker(worker_id): async with sem: print("Worker %d is working" % worker_id) await use_some_resource() # Now the semaphore has been released. print("Worker %d is done" % worker_id) For compatibility with older versions of Python, `.acquire` is a context manager, so ``worker`` could also be written as:: @gen.coroutine def worker(worker_id): with (yield sem.acquire()): print("Worker %d is working" % worker_id) yield use_some_resource() # Now the semaphore has been released. print("Worker %d is done" % worker_id) .. versionchanged:: 4.3 Added ``async with`` support in Python 3.5. rNvaluercs$t|dkrtd||_dS)Nrz$semaphore initial value must be >= 0)r+r ValueErrorrSrrkr/rrr~s zSemaphore.__init__rcsPt}|jdkrdn d|j}|jrr)r+r4rSformatrr2)rresZextrar/rrr4s  zSemaphore.__repr__cCsJ|jd7_|jrF|j}|s|jd8_|t|qFqdS)*Increment the counter and wake one waiter.rN)rSrrHr!rXr]r8rrrres zSemaphore.releaser5cstjdkr.jd8_tnNj|r|ddfdd }tj || fddS) zDecrement the counter. Returns an awaitable. Block if the counter is zero and wait for a `.release`. The awaitable raises `.TimeoutError` after the deadline. rrNrcs"stdSr )r!Z set_exceptionr TimeoutErrorr&rr8rrr:sz%Semaphore.acquire..on_timeoutcs Sr r;r<r>rrr@r%z#Semaphore.acquire..) rrSrXr]rrArr,r-rBrCrDrrEracquires     zSemaphore.acquirecCs tddS)Nz0Use 'async with' instead of 'with' for Semaphore RuntimeErrorrrrrr`szSemaphore.__enter__ra)typrk tracebackrcCs |dSr r`)rrwrkrxrrrrfszSemaphore.__exit__cs|IdHdSr rtrrrr __aenter__szSemaphore.__aenter__rwrktbrcs |dSr rerrwrkr}rrr __aexit__szSemaphore.__aexit__)r)N)r'r(r)r*rQrrLr4rerrrMrNrOr r]rtr`rgrhrirfr{rrRrrr/rrs*_   rcs<eZdZdZd eddfdd Zddfdd ZZS) ra:A semaphore that prevents release() being called too many times. If `.release` would increment the semaphore's value past the initial value, it raises `ValueError`. Semaphores are mostly used to guard resources with limited capacity, so a semaphore released too many times is a sign of a bug. rNrjcstj|d||_dS)Nrk)r+r_initial_valuermr/rrrszBoundedSemaphore.__init__rcs"|j|jkrtdtdS)rrz!Semaphore released too many timesN)rSrrlr+rerr/rrres zBoundedSemaphore.release)r)r'r(r)r*rQrrerRrrr/rrsrc@seZdZdZddddZedddZdeee e j fe e dd d Zddd d Zddd dZdeeeejddddZddddZdeeeejddddZdS)raA lock for coroutines. A Lock begins unlocked, and `acquire` locks it immediately. While it is locked, a coroutine that yields `acquire` waits until another coroutine calls `release`. Releasing an unlocked lock raises `RuntimeError`. A Lock can be used as an async context manager with the ``async with`` statement: >>> from tornado import locks >>> lock = locks.Lock() >>> >>> async def f(): ... async with lock: ... # Do something holding the lock. ... pass ... ... # Now the lock is released. For compatibility with older versions of Python, the `.acquire` method asynchronously returns a regular context manager: >>> async def f2(): ... with (yield lock.acquire()): ... # Do something holding the lock. ... pass ... ... # Now the lock is released. .. versionchanged:: 4.3 Added ``async with`` support in Python 3.5. NrcCstdd|_dS)Nrr)r_blockrrrrr sz Lock.__init__cCsd|jj|jfS)Nz<%s _block=%s>)r0r'rrrrrr4sz Lock.__repr__r5cCs |j|S)zAttempt to lock. Returns an awaitable. Returns an awaitable, which raises `tornado.util.TimeoutError` after a timeout. )rrt)rr6rrrrtsz Lock.acquirecCs.z|jWnty(tdYn0dS)zUnlock. The first coroutine in line waiting for `acquire` gets the lock. If not locked, raise a `RuntimeError`. zrelease unlocked lockN)rrerlrvrrrrres z Lock.releasecCs tddS)Nz+Use `async with` instead of `with` for Lockrurrrrr`'szLock.__enter__rar|cCs |dSr ryrrrrrf*sz Lock.__exit__cs|IdHdSr rzrrrrr{2szLock.__aenter__cs |dSr r~rrrrr5szLock.__aexit__)N)r'r(r)r*rrLr4rrrMrNrOr r]rtrer`rgrhrirfr{rrrrrrs*$   r)rrNrhZtornadorrZtornado.concurrentrrtypingrrrr r TYPE_CHECKINGr r __all__objectrr rr]rrrrrrrs"md5