cgroups inquiry

I have multiple tasks running, each with a controlling terminal. Is there anything in cgroups that would allow me to pass a signal from one of these tasks to all the others. It seems I can't use kill(3) because it appears all these processes would have to be in the same process group and only a single controlling terminal is allowed per process group??

Is this a correct assumption?

Is there a way to eliminate the "single controlling terminal" requirement per process group?

Can cgroups help me in any way?

I can't use any sort of poll/select method. I need signals.

Thanks and regards
Mark