On Friday, 11 August 2017 at 21:58:20 UTC, Johnson wrote:
Just a thought, maybe the GC isn't cleaning up quick enough?
You are allocating and md5 digest each iteration.
Possibly, an opitimization is use use a collection of md5
hashes and reuse them. e.g., pre-allocate 100(you probably only
need as many as the number of parallel loops going) and then
attempt to resuse them. If all are in use, wait for a free one.
Might require some synchronization.
John, thanks. That was it. md.d has nifty function that is
straightforward than the OOP version.
void main(string args)
foreach (d; parallel(dirEntries(args,
SpanMode.depth).filter!(f => f.isFile), 1))
auto data = cast(const(ubyte)) read(d.name);
auto hash = md5Of(data);
string t = split(d.name, '/');
writeln(toHexString(hash), " ", t[$-1]);
Also I expected the performance to be faster than `md5sum`.
However, that was not the case. Please see below. Is there anyway
to optimize this further?
11-08-2017 17:22:54 vaalaham ~/code/d/d-mpmc-sample
$ time find /home/arun/downloads/boost_1_64_0/ -type f | xargs
md5sum >/dev/null 2>&1
11-08-2017 17:23:16 vaalaham ~/code/d/d-mpmc-sample
$ ldc2 pmd.d -O3
11-08-2017 17:23:31 vaalaham ~/code/d/d-mpmc-sample
$ time ./pmd ~/downloads/boost_1_64_0 > /dev/null
11-08-2017 17:23:37 vaalaham ~/code/d/d-mpmc-sample
strace showed lots of futex exchanges. Why would that be?