<s>
Rendezvous	B-Operating_System
is	O
a	O
data	B-General_Concept
synchronization	I-General_Concept
mechanism	O
in	O
Plan	B-Operating_System
9	I-Operating_System
from	I-Operating_System
Bell	I-Operating_System
Labs	I-Operating_System
.	O
</s>
<s>
It	O
is	O
a	O
system	B-Operating_System
call	I-Operating_System
that	O
allows	O
two	O
processes	B-Operating_System
to	O
exchange	O
a	O
single	O
datum	O
while	O
synchronizing	O
.	O
</s>
<s>
The	O
rendezvous	B-Operating_System
call	O
takes	O
a	O
tag	O
and	O
a	O
value	O
as	O
its	O
arguments	O
.	O
</s>
<s>
The	O
tag	O
is	O
typically	O
an	O
address	O
in	O
memory	O
shared	O
by	O
both	O
processes	B-Operating_System
.	O
</s>
<s>
Calling	O
rendezvous	B-Operating_System
causes	O
a	O
process	O
to	O
sleep	O
until	O
a	O
second	O
rendezvous	B-Operating_System
call	O
with	O
a	O
matching	O
tag	O
occurs	O
.	O
</s>
<s>
Then	O
,	O
the	O
values	O
are	O
exchanged	O
and	O
both	O
processes	B-Operating_System
are	O
awakened	O
.	O
</s>
<s>
See	O
also	O
mutual	B-Operating_System
exclusion	I-Operating_System
.	O
</s>
