Alvaro Herrera <alvherre@commandprompt.com> writes:
> We could have the postmaster signal the launcher, but the signal cannot
> contain much useful info because the postmaster does generally not want
> to write in shared memory.
The postmaster already touches/writes in shared memory in pmsignal.c.
The trick here is that whatever it does should be sufficiently
constrained that arbitrarily-bad corruption of shared memory can't
crash or freeze the postmaster. If you can meet that restriction,
feel free to introduce some more signaling knowledge.
regards, tom lane