term% cat index.txt RENDEZVOUS(2) System Calls Manual RENDEZVOUS(2)
NAME
rendezvous - user level process synchronization
SYNOPSIS
#include <u.h>
#include <libc.h>
void* rendezvous(void* tag, void* value)
DESCRIPTION
The rendezvous system call allows two processes to synchronize and ex‐
change 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 ex‐
changed between the processes and returned as the result of the respec‐
tive 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.
SOURCE
/sys/src/libc/9syscall
SEE ALSO
fork(2), lock(2), segattach(2)
DIAGNOSTICS
Sets errstr.
RENDEZVOUS(2)