Terminology confusion: buffered vs asynchronous

• To: netcdfgroup@xxxxxxxxxxxxxxxx
• Subject: Terminology confusion: buffered vs asynchronous
• From: "Glenn P. Davis" <davis@xxxxxxxxxxxxxxxx>
• Date: Thu, 5 Sep 1996 16:21:10 -0600

I recently posted an "answer" to a question about netcdf and
"asynchronous" io.  I took "asynchronous" to mean that the system
calls for io are not synchronous with the netcdf calls, eg, that
they are "buffered".

It could be that question referred to another class of asynchronous io,
such as is available via the "aioread()","aiowrite()", and "aiowait()"
library calls on some system, and as available in some FORTRAN systems
via the BUFFERIN or BUFFEROUT statements. These allow computation to
continue concurrently with io. Netcdf does not use these facilities.
A netcdf-3 ncio layer could be written to use these, modulo two
problems:
  1) synchronization primitives to guarantee serialization of io operations.
  2) some method of dealing with any asynchronous io errors

-glenn