[TUHS] Synchronous vs Asynchronous IO in Unix

Peter Jeremy peter at rulingia.com
Sun Sep 20 14:38:58 AEST 2015

Why were the original read(2) and write(2) system calls written to offer
synchronous I/O only?  It's relatively easy to create synchronous I/O
functions given asynchronous I/O primitives but it's impossible to do the

Multics (at least) supported asynchronous I/O so the concept wasn't novel.
And any multi-tasking kernel has to support asynchronous I/O internally so
suitable code exists in the kernel.

Peter Jeremy
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 949 bytes
Desc: not available
URL: <http://minnie.tuhs.org/pipermail/tuhs/attachments/20150920/ac6337df/attachment.sig>

More information about the TUHS mailing list