<s>
Input/output	B-Library
completion	I-Library
port	I-Library
(	O
IOCP	B-Library
)	O
is	O
an	O
API	B-Application
for	O
performing	O
multiple	O
simultaneous	O
asynchronous	B-Architecture
input/output	I-Architecture
operations	O
in	O
Windows	B-Device
NT	I-Device
versions	O
3.5	O
and	O
later	O
,	O
AIX	O
and	O
on	O
Solaris	B-Application
10	I-Application
and	O
later	O
.	O
</s>
<s>
An	O
input/output	B-Library
completion	I-Library
port	I-Library
object	O
is	O
created	O
and	O
associated	O
with	O
a	O
number	O
of	O
sockets	O
or	O
file	B-Application
handles	I-Application
.	O
</s>
<s>
When	O
I/O	O
services	O
are	O
requested	O
on	O
the	O
object	O
,	O
completion	O
is	O
indicated	O
by	O
a	O
message	B-Architecture
queued	O
to	O
the	O
I/O	B-Library
completion	I-Library
port	I-Library
.	O
</s>
<s>
A	O
process	O
requesting	O
I/O	O
services	O
is	O
not	O
notified	O
of	O
completion	O
of	O
the	O
I/O	O
services	O
,	O
but	O
instead	O
checks	O
the	O
I/O	B-Library
completion	I-Library
port	I-Library
's	O
message	B-Operating_System
queue	I-Operating_System
to	O
determine	O
the	O
status	O
of	O
its	O
I/O	O
requests	O
.	O
</s>
<s>
The	O
I/O	B-Library
completion	I-Library
port	I-Library
manages	O
multiple	O
threads	B-Operating_System
and	O
their	O
concurrency	B-Operating_System
.	O
</s>
