Signal is a list of registered asynchronous callbacks.
The signal’s life-cycle has two stages: after creation its content
could be filled by using standard list operations:
sig.freeze() call the signal is frozen: adding, removing
and dropping callbacks are forbidden.
The only available operation is calling previously registered
For concrete usage examples see signals in aiohttp.web chapter.
Changed in version 3.0:
sig.send() call is forbidden for non-frozen signal.
Support for regular (non-async) callbacks is dropped. All callbacks should be async functions.
- class aiohttp.Signal¶
The signal, implements
- coroutine send(*args, **kwargs)¶
Call all registered callbacks one by one starting from the begin of list.
Freeze the list. After the call any content modification is forbidden.