used to guard resources with limited capacity, so a semaphore released too many times is a sign of a bug. release() → None Increment the counter and wake one waiter. acquire(timeout: float | timedelta loaded in a Chrome tab. 6.9 Release notes 6.9.1 What’s new in Tornado 6.5.1 May 22, 2025 Bug fixes • Fixed a bug in multipart/form-data parsing that could incorrectly reject filenames containing characters Now an exception is raised at the first error, so there is only one log message per request. This fixes CVE-2025-47287. General Changes • Python 3.14 is now supported. Older versions of Tornado will work

used to guard resources with limited capacity, so a semaphore released too many times is a sign of a bug. release() → None Increment the counter and wake one waiter. acquire(timeout: Union[float, datetime asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy()) for this platform/version. Bug fixes • Fixed an issue in IOStream (introduced in 6.0.0) that resulted in StreamClosedError being incorrectly notes 155 Tornado Documentation, Release 6.1 6.9.3 What’s new in Tornado 6.0.3 Jun 22, 2019 Bug fixes • gen.with_timeout always treats asyncio.CancelledError as a quiet_exception (this im- proves compatibility

used to guard resources with limited capacity, so a semaphore released too many times is a sign of a bug. release() → None Increment the counter and wake one waiter. acquire(timeout: Union[float, datetime for this platform/version. 150 Chapter 6. Documentation Tornado Documentation, Release 6.0.4 Bug fixes • Fixed an issue in IOStream (introduced in 6.0.0) that resulted in StreamClosedError being incorrectly always uses the selector event loop on Windows. 6.9.2 What’s new in Tornado 6.0.3 Jun 22, 2019 Bug fixes • gen.with_timeout always treats asyncio.CancelledError as a quiet_exception (this im- proves compatibility

used to guard resources with limited capacity, so a semaphore released too many times is a sign of a bug. release() → None Increment the counter and wake one waiter. acquire(timeout: Optional[Union[float throughout the package. • CI has moved from Travis and Appveyor to Github Actions. tornado.gen • Fixed a bug in which WaitIterator.current_index could be incorrect. • tornado.gen.TimeoutError is now an alias asyncio. set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy()) for this platform/version. Bug fixes • Fixed an issue in IOStream (introduced in 6.0.0) that resulted in StreamClosedError being incorrectly

used to guard resources with limited capacity, so a semaphore released too many times is a sign of a bug. release() → None Increment the counter and wake one waiter. 6.5. Coroutines and concurrency 127 throughout the package. • CI has moved from Travis and Appveyor to Github Actions. tornado.gen • Fixed a bug in which WaitIterator.current_index could be incorrect. • tornado.gen.TimeoutError� is now an alias for this platform/version. 166 Chapter 6. Documentation Tornado Documentation, Release 6.2 Bug fixes • Fixed an issue in IOStream (introduced in 6.0.0) that resulted in StreamClosedError being incorrectly

used to guard resources with limited capacity, so a semaphore released too many times is a sign of a bug. release() → None Increment the counter and wake one waiter. acquire(timeout: Optional[Union[float throughout the package. • CI has moved from Travis and Appveyor to Github Actions. tornado.gen • Fixed a bug in which WaitIterator.current_index could be incorrect. • tornado.gen.TimeoutError is now an alias asyncio. set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy()) for this platform/version. Bug fixes • Fixed an issue in IOStream (introduced in 6.0.0) that resulted in StreamClosedError being incorrectly

used to guard resources with limited capacity, so a semaphore released too many times is a sign of a bug. release() → None Increment the counter and wake one waiter. acquire(timeout: Optional[Union[float throughout the package. • CI has moved from Travis and Appveyor to Github Actions. tornado.gen • Fixed a bug in which WaitIterator.current_index could be incorrect. • tornado.gen.TimeoutError is now an alias asyncio. set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy()) for this platform/version. Bug fixes • Fixed an issue in IOStream (introduced in 6.0.0) that resulted in StreamClosedError being incorrectly

used to guard resources with limited capacity, so a semaphore released too many times is a sign of a bug. release() → None Increment the counter and wake one waiter. acquire(timeout: Optional[Union[float throughout the package. • CI has moved from Travis and Appveyor to Github Actions. tornado.gen • Fixed a bug in which WaitIterator.current_index could be incorrect. • tornado.gen.TimeoutError is now an alias for this platform/version. 170 Chapter 6. Documentation Tornado Documentation, Release 6.3.3 Bug fixes • Fixed an issue in IOStream (introduced in 6.0.0) that resulted in StreamClosedError being incorrectly

used to guard resources with limited capacity, so a semaphore released too many times is a sign of a bug. release() Increment the counter and wake one waiter. acquire(timeout=None) Decrement the counter being loaded in a Chrome tab. 5.9 Release notes 5.9.1 What’s new in Tornado 5.1.1 Sep 16, 2018 Bug fixes • Fixed an case in which the Future returned by RequestHandler.finish could fail to resolve. • deprecated and will be removed in Tornado 6.0. 5.9.3 What’s new in Tornado 5.0.2 Apr 7, 2018 Bug fixes • Fixed a memory leak when IOLoop objects are created and destroyed. • If AsyncTestCase.get_new_ioloop

used to guard resources with limited capacity, so a semaphore released too many times is a sign of a bug. release() → None [https://docs.python.org/3/library/constants.html#None] Increment the counter and 2010 What’s new in Tornado 1.0 July 22, 2010What’s new in Tornado 6.5.1 May 22, 2025 Bug fixes Fixed a bug in multipart/form-data parsing that could incorrectly reject filenames containing characters Now an exception is raised at the first error, so there is only one log message per request. This fixes CVE- 2025-47287 [https://github.com/tornadoweb/tornado/security/advisories/GHSA-7cx3-6m66-7c5m].