On Thu, Apr 21, 2016 at 07:43:29AM -0700, Paul Eggert wrote:
On 04/21/2016 02:55 AM, arn...@skeeve.com wrote:
it
would be a very suprising change in behavior if output from multiple
files comes out interleaved, instead of in the order the files were
specified on the command line.
I presume that computation is interleaved but the output order is the
same as before, unless the user specifies an option saying speed
trumps predictability.
For what it's worth, the command-line flag added by my multithreading
patch series as it currently stands is pretty much that (speed over
predictability). In the interest of simplicity, it omits per-file
output buffering and just outputs matching lines as they are found --
the non-determinism this introduces into its output is the reason it's
left as an opt-in command-line flag and not on by default.
[Strictly speaking even in the default "single-threaded" mode it *is* in
fact actually multi-threaded, but there's only one search thread, so
output ordering is unaffected. In theory even this could allow a slight
performance improvement by overlapping pattern-matching with directory
traversal and prefetching in the master thread, but I'd guess it's
probably negligible in most cases, and isn't really the goal of the
patches.]
Zev Weiss
