Input/output completion port

{{redirect|IOCP|the program on IBM mainframes|Input/Output Configuration Program}}

Input/output completion port (IOCP) is an API for performing multiple simultaneous asynchronous input/output operations in Windows NT versions 3.5 and later,[http://msdn.microsoft.com/en-us/library/aa365198(VS.85).aspx Windows I/O Completion Ports] AIX[https://www.ibm.com/support/knowledgecenter/en/SSEPGG_11.1.0/com.ibm.db2.luw.admin.perf.doc/doc/t0054518.html Configuring IOCP on AIX 5 and 6] and on Solaris 10 and later.{{cite web|url=http://developers.sun.com/solaris/articles/event_completion.html |title=Solaris 10 I/O Completion Ports |accessdate=2008-07-20 |url-status=bot: unknown |archiveurl=https://web.archive.org/web/20110719052845/http://developers.sun.com/solaris/articles/event_completion.html |archivedate=July 19, 2011 }} An input/output completion port object is created and associated with a number of sockets or file handles. When I/O services are requested on the object, completion is indicated by a message queued to the I/O completion port. A process requesting I/O services is not notified of completion of the I/O services, but instead checks the I/O completion port's message queue to determine the status of its I/O requests. The I/O completion port manages multiple threads and their concurrency.