Add an equivalent to `isInIOThread` as a reactor method

	@exarkun reported
Trac ID	trac#5153
Type	enhancement
Created	2011-06-13 21:46:24Z

twisted.python.threadable.isInIOThread is usable to determine if the code calling it is executing in the same thread as the reactor. This may be useful for making certain decisions (though Twisted doesn't currently use it anywhere outside of the test suite).

Notice the problem with that, however: the reactor. This API gets in the way of supporting multiple reactors, since its behavior no longer makes any sense once you have reactors running in more than one thread.

It could be replaced by a new reactor method which determines if the calling code is running in the same thread as the reactor the method is called on is running. This probably makes sense as a method on IReactorThreads, if we're allowed to add new methods to reactor interfaces (I forget if we are or not).

Once this is in place, we can deprecate twisted.python.threadable.isInIOThread and point at the reactor method to replace it.

trac-id__5153 5153
type__enhancement enhancement
reporter__exarkun exarkun
priority__low low
milestone__ 
branch__ 
branch_author__ 
status__new new
resolution__None None
component__core core
keywords__ 
time__1308001584000000 1308001584000000
changetime__1308001584000000 1308001584000000
version__None None
owner__ 

Start with twisted.python.threadable.isInIOThread and the IReactorThreads interface, then inspect the reactor implementations that would provide the reactor-specific behavior. Check the test suite for existing isInIOThread coverage. Done means a reactor method distinguishes its own thread, the legacy helper can be deprecated with a replacement reference, and the behavior is tested.