Writing a program to be executed from Make and participate in the job server protocol

[Zack Weinberg]

I'd like to write a program that, when invoked appropriately from
inside a parallel make run, participates in the job server protocol.
Specifically, I have three test suites that get run (using the same
controller program) from "make check", and I'd like "make -jN check"
to parallelize individual test cases.  (One of the test suites is much
larger than the other two.)  The logical way to do this is to code the
controller to talk to the job server.

I need help both with writing the code inside the testsuite controller
that speaks to the job server, and with writing the Makefile so that
Make knows to pass appropriate flags down to the child job ('as if' it
were a recursive make invocation).

(I don't think it is practical to make the test controller *be* a
recursive make invocation.)

Thanks -
zw