parameterize reactor in twisted.application.internet services

[exarkun]

The unpleasant way ports are bound and connections are made by the internet services means that it is difficult or impossible to test this code without actually hitting the network. This is likewise for application code (such as makeService implementations) which creates these objects.

It should be possible to specify the reactor used by these classes.

[therve]

(In [22037]) Branching to 'service-reactor-2937'

[therve]

(In [22038]) Make reactor parametrizable in clients and servers.

Refs #2937

[therve]

This is ready to review!

[exarkun]

The implementations of _getPort and _getConnection won't work as expected the second time they're invoked (eg, startService, stopService, startService).

I guess there should be some test coverage for the repeated use of the same service object.

[therve]

(In [22051]) Remove the 'reactor' keyword in init, add tests for multiple start, some docs.

Refs #2937

[therve]

Oups, thanks, I had missed that. Back to review.

[exarkun]

pyflakes warnings on test_application.py:

• twisted/test/test_application.py:20: 'microdom' imported but unused
• twisted/test/test_application.py:591: redefinition of fuction 'test_reactorParametrizationInClient' from line 553

_getPort and _getConnection could probably use some docstrings.

Other than those issues, I think it looks good. No need for re-review unless you notice something else.

[therve]

(In [22161]) Rename a test, add some docstrings to internal methods.

Refs #2937

[therve]

(In [22163]) Merge service-reactor-2937

Author: therve Reviewer: exarkun Fixes #2937

Add a reactor keyword for services in twisted.application.internet so that we can test this code more easily without hitting the network.