o Q_D@sddlZddlZddlZddlmZmZddlmZmZddl m Z m Z m Z m Z mZddl Z e jr9ddl mZmZgdZGdddeZGd d d eZGd d d eZGd ddeZGdddeZGdddeZGdddeZdS)N)genioloop)Future"future_set_result_unless_cancelled)UnionOptionalTypeAny Awaitable)DequeSet) ConditionEvent SemaphoreBoundedSemaphoreLockc@s$eZdZdZdddZdddZdS) _TimeoutGarbageCollectorzBase class for objects that periodically clean up timed-out waiters. Avoids memory leak in a common pattern like: while True: yield condition.wait(short_timeout) print('looping....') returnNcCst|_d|_dS)Nr) collectionsdeque_waiters _timeoutsselfr//usr/lib/python3/dist-packages/tornado/locks.py__init__)s  z!_TimeoutGarbageCollector.__init__cCs>|jd7_|jdkrd|_tdd|jD|_dSdS)Ndrcss|] }|s|VqdSN)done).0wrrr 2sz<_TimeoutGarbageCollector._garbage_collect..)rrrrrrrr_garbage_collect-s  z)_TimeoutGarbageCollector._garbage_collectrN)__name__ __module__ __qualname____doc__rr$rrrrrs rcsveZdZdZdfdd ZdefddZ ddeee e j fde e fd d Zdd eddfd dZdddZZS)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`. rNcsttj|_dSr)superrrIOLoopcurrentio_loopr __class__rrrqs zCondition.__init__cCs.d|jjf}|jr|dt|j7}|dS)Nz<%sz waiters[%s]>)r/r&rlen)rresultrrr__repr__uszCondition.__repr__timeoutcsTtj|r(dfdd }tj||fddS)zWait for `.notify`. Returns a `.Future` that resolves ``True`` if the condition is notified, or ``False`` after a timeout. rNcss tddSNF)r rr$rrwaiterrr on_timeouts  z"Condition.wait..on_timeoutc Srremove_timeout_r-timeout_handlerr z Condition.wait..r%)rrappendrr+r, add_timeoutadd_done_callbackrr4r8rr-rr?r7rwait{s   zCondition.waitrncCsTg}|r|jr|j}|s|d8}|||r|js|D]}t|dq dS)zWake ``n`` waiters.rTN)rpopleftr rBr)rrHwaitersr7rrrnotifys     zCondition.notifycCs|t|jdS)zWake all waiters.N)rKr1rrrrr notify_allszCondition.notify_allr%rr)r&r'r(r)rstrr3rrfloatdatetime timedeltar boolrGintrKrL __classcell__rrr.rr 5s;  r c@sreZdZdZdddZdefddZdefdd Zdd d Z dd d Z dde e e ejfdedfddZdS)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 rNcCsd|_t|_dSr5)_valuesetrrrrrrs zEvent.__init__cCs d|jj|r dfSdfS)Nz<%s %s>rVclear)r/r&is_setrrrrr3s  zEvent.__repr__cCs|jS)z-Return ``True`` if the internal flag is true.rUrrrrrXsz Event.is_setcCs2|jsd|_|jD] }|s|dq dSdS)zSet the internal flag to ``True``. All waiters are awakened. Calling `.wait` once the flag is set will not block. TN)rUrr set_result)rfutrrrrVs  z Event.setcCs d|_dS)zkReset the internal flag to ``False``. Calls to `.wait` will block until `.set` is called. FNrYrrrrrWs z Event.clearr4csftjr dSjfdd|dur"St|}|fdd|S)zBlock until the internal flag is true. Returns an awaitable, which raises `tornado.util.TimeoutError` after a timeout. Ncs j|Sr)rremover[rrrr@s zEvent.wait..cssSdSr)r cancel)tfr]rrr@s)rrUrZraddrDr with_timeout)rr4 timeout_futr)r[rrrGs    z Event.waitr%r)r&r'r(r)rrNr3rRrXrVrWrrrOrPrQr rGrrrrrs '  rc@sPeZdZdZdeddfddZdddZd d d eed ee j ddfd dZ dS)_ReleasingContextManagerzReleases a Lock or Semaphore at the end of a "with" statement. with (yield semaphore.acquire()): pass # Now semaphore.release() has been called. objrNcCs ||_dSr)_obj)rrdrrrrs z!_ReleasingContextManager.__init__cCsdSrrrrrr __enter__sz"_ReleasingContextManager.__enter__exc_typeOptional[Type[BaseException]]exc_valexc_tbcCs|jdSr)rerelease)rrgrirjrrr__exit__sz!_ReleasingContextManager.__exit__r%) r&r'r(r)r rrfr BaseExceptiontypes TracebackTyperlrrrrrcs rccseZdZdZddeddffdd Zdeffdd Zdd d Z dd e e e e j fdeefd dZdddZddde ede ejddfddZdddZddde ede ejddfddZZS)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. rvaluerNcs$t|dkr td||_dS)Nrz$semaphore initial value must be >= 0)r*r ValueErrorrUrrpr.rrr~s  zSemaphore.__init__csPt}|jdkr dnd|j}|jrd|t|j}d|dd|S)Nrlockedzunlocked,value:{0}z{0},waiters:{1}z <{0} [{1}]>r)r*r3rUformatrr1)rresextrar.rrr3s zSemaphore.__repr__cCsT|jd7_|jr(|j}|s#|jd8_|t|dS|js dSdS)*Increment the counter and wake one waiter.rN)rUrrIr rZrcr6rrrrks zSemaphore.releaser4cs~tjdkrjd8_tSj|r=d fdd }tj || fddS) zDecrement the counter. 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Semaphores are mostly used to guard resources with limited capacity, so a semaphore released too many times is a sign of a bug. rrprNcstj|d||_dS)Nrp)r*r_initial_valuerrr.rrrs zBoundedSemaphore.__init__cs"|j|jkr tdtdS)rxz!Semaphore released too many timesN)rUrrqr*rkrr.rrrks zBoundedSemaphore.releaserMr%)r&r'r(r)rSrrkrTrrr.rrsrc@seZdZdZdddZdefddZ ddeee e j fde e fd d Zdd d Zdd dZdddeedeejddfddZdddZdddeedeejddfddZdS)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. rNcCstdd|_dS)Nrr)r_blockrrrrr sz Lock.__init__cCsd|jj|jfS)Nz<%s _block=%s>)r/r&rrrrrr3sz Lock.__repr__r4cCs |j|S)zAttempt to lock. Returns an awaitable. Returns an awaitable, which raises `tornado.util.TimeoutError` after a timeout. )rr{)rr4rrrr{s z Lock.acquirecCs(z|jWdStytdw)zUnlock. The first coroutine in line waiting for `acquire` gets the lock. If not locked, raise a `RuntimeError`. zrelease unlocked lockN)rrkrqr~rrrrrks  z Lock.releasecCr|)Nz+Use `async with` instead of `with` for Lockr}rrrrrf'rzLock.__enter__rrhrprcCrrrrrrrrl*rz Lock.__exit__crrrrrrrr2rzLock.__aenter__crrrrrrrr5rzLock.__aexit__r%r)r&r'r(r)rrNr3rrrOrPrQr rcr{rkrfrmrnrorlrrrrrrrs> $  r)rrPrntornadorrtornado.concurrentrrtypingrrrr r TYPE_CHECKINGr r __all__objectrr rrcrrrrrrrs$md5