Rendezvous (Plan 9)

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Rendezvous is a data synchronization mechanism in Plan 9 from Bell Labs. It is a system call that allows two processes to exchange a single datum while synchronizing.{{Cite journal |last=Pike |first=Rob |last2=Presotto |first2=Dave |last3=Dorward |first3=Sean |last4=Flandrena |first4=Bob |last5=Thompson |first5=Ken |last6=Trickey |first6=Howard |last7=Winterbottom |first7=Phil |date=1995 |title=Plan 9 from Bell Labs |journal=Computing systems |publisher=University of California Press |volume=8 |issue=3 |pages=221–254}}

The rendezvous call takes a tag and a value as its arguments. The tag is typically an address in memory shared by both processes. Calling rendezvous causes a process to sleep until a second rendezvous call with a matching tag occurs. Then, the values are exchanged and both processes are awakened.

More complex synchronization mechanisms can be created from this primitive operation. See also mutual exclusion.