device_printf does multiple calls to printf allowing other console messages to
be inserted between the device name, and the rest of the message. This change
uses sbuf to compose to two into a single buffer, and prints it all at once.
It exposes an sbuf drain function (drain-to-printf) for common use.
Update documentation to match; some unit tests included.
Submitted by: jmg
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D16690
Previous spellings of my name (NGie, Ngie) weren't my legal spelling. Use Enji
instead for clarity.
While here, remove "All Rights Reserved" from copyrights I "own".
MFC after: 1 week
Areas not covered still [positive functionality wise] are:
- sbuf_{clear,get,set}_flags
- sbuf_new (in particular, with fixed buffers, etc).
Some basic negative testing has been added, but more will be added in the
future.
This work was in part to validate work done by cem in r288223, and ian
before that.
MFC after: 2 months
Sponsored by: Dell EMC Isilon
