IPC (or how to "bounce" a running zsh?)

[<kynn@xxxxxxxxx>]

Is there any mechanism for interprocess communication in which at
least one of the processes is a running zsh?

TIA!

kj

P.S. The context of this question is the problem of "bouncing" a
running zsh, i.e. telling it somehow to re-source the appropriate .z*
files (according to whether or not it is an interactive/login shell).
(I realize that I could solve this problem by adding one more task to
my poor overworked preexec or precmd, and coax it to do a "poor man's
IPC", namely to check for the presence of a sentinel file, perform the
appropriate re-sourcing, and delete the sentinel; this opens the
possibility of a race condition, but I'm sure there is a way to deal
with it.)