RedisChannelLayer.receive runs forever

[AlexejStukov]

RedisChannelLayer.receive, that was reworked in #43, now hangs forever if called with block. That was not the case in the previous version (it returned (None, None). This prevents channels Worker from exiting if termed is set to true (e.g. in the signal handler).

[andrewgodwin]

The ASGI spec says "block means that the call can take as long as it likes", so this is valid behaviour. What needs fixing here is the channels Worker; if you could file a bug against the channels project we can fix it over there so an interrupt correctly yanks it out of any receive call.

[AlexejStukov]

@andrewgodwin: Done.
@andrewgodwin & @proofit404: Maybe I will try my luck at fixing this in channels tomorrow. Thanks for your work, guys!

[AlexejStukov]

@andrewgodwin maybe the ASGI spec should be reworded, because in the same paragraph there is the sentence: "If block is True, then it will not return until after a built-in timeout or a message arrives;"
For me that means that it should eventually return after a non infinite timeout.

[andrewgodwin]

Yes, I will clarify that paragraph so it's clear it is allowed to block forever.