term% ls -F
term% cat index.txt
RENDEZVOUS(2)                 System Calls Manual                RENDEZVOUS(2)

       rendezvous - user level process synchronization

       #include <u.h>
       #include <libc.h>

       void* rendezvous(void* tag, void* value)

       The  rendezvous  system  call  allows  two processes to synchronize and
       exchange a value.  In conjunction with the shared memory  system  calls
       (see segattach(2) and fork(2)), it enables parallel programs to control
       their scheduling.

       Two processes wishing to synchronize call rendezvous with a common tag,
       typically  an address in memory they share.  One process will arrive at
       the rendezvous first; it suspends execution  until  a  second  arrives.
       When  a  second  process  meets  the rendezvous the value arguments are
       exchanged between the processes and  returned  as  the  result  of  the
       respective  rendezvous  system calls.  Both processes are awakened when
       the rendezvous succeeds.

       The set of tag values which two processes may use  to  rendezvous—their
       tag  space—is  inherited  when a process forks, unless RFREND is set in
       the argument to rfork; see fork(2).

       If a rendezvous is interrupted the return value is ~0,  so  that  value
       should not be used in normal communication.


       fork(2), lock(2), segattach(2)

       Sets errstr.