HELP on process communication on SunOS.

I am using Sun Sparc 2, SunOS
I am trying to following...

--------------
Process 1:

 While(1)
 {
   Sleep until receive signal prom process 2
   printf(" I am awake\n");
 }
------------------

Process 2:

Send signal to process 1 to wake up.
--------------------------------

I have try to use signals, and Semaphores.
I was not able to run a simple example.

In semaphores, I was not able to make
process sleep.

If you have set of function than can do
this or if you have any other suggestions.
plase let me know.

Thanks in advance..

cengelog@dab.ge.com