RENDEZVOUS(2) 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 synchro-
nize 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.
SOURCE
/sys/src/libc/9syscall
SEE ALSO
fork(2), lock(2), segattach(2)
DIAGNOSTICS
Sets errstr.
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