These are Erlang bindings to libuv. There goals for this project are to create a stable binding to libuv's file handling and demonstrate how that affects file IO for processes with large mailboxes.
If that work goes quickly enough I'll add wrappers to the networking parts of libuv and lastly if time I'll add the HTTP parser from node and compare that against Erlang's builtin HTTP packet parsing.
I've managed to resurect the hopes for this project by doing a bit of work hacking in Erlang assembly. The caveat is that this is a bit of a hack though it should work well enough for our purposes.
If you have to edit euv.erl then you'll also have to regenerate the euv.S
file and manually edit it by hand to reintroduce the selective receive
optimizations. I've written a rebar plugin that automatically checks that
euv.S is tagged with the MD5 of euv.erl so that we don't accidentally
lose this condition. It also builds euv.beam from euv.S so that we
aren't including a .beam directly in Git.
This is definitely playing with fire. The Erlang assembly format is undocumented and subject to change. While this will serve us well enough for the time being and seems to work, basing large projects on this code at present is ill advised as the OTP team may decide to change things out from under us (which they have big warnings about).
That said, who doesn't like living on the edge every now and again?
Theoretically you should be able to build this on OS X by just running
make in the top directory.
The tests I was using are:
$ ./test/example-problem.es
$ ERL_FLAGS="-pa ebin" ./test/example-using-euv.es
You should notice that the increase in times for the tests are now
drastically different. On my late 2010 MacBook Air (SSD) I'm getting
nearly 90s for the builtin file module and between 9 and 10s using
euv. Although on the small queue end I'm running slower by nearly
half a second (1.2 vs 1.65s). To be a viable replacement I'll have to
track that down and at least be on parity.
Benchmarking (in "air-quotes") with Erlang R16B01 on a Lenovo X1 Carbon laptop (Intel(R) Core(TM) i7-3667U CPU @ 2.00GHz) with 8 GB of RAM and an SSD drive (ext4:noatime,discard) resulted in the following:
With the Erlang/libuv NIF:
ERL_FLAGS="-S 2:4 +h 4096 -sbdt nnts -pa ebin" ./test/example-using-euv.es
0 :: 2.71s
10 :: 2.63s
1000 :: 2.35s
10000 :: 2.48s
100000 :: 7.76s
1000000 :: 59.49s
The Erlang file module:
ERL_FLAGS="-S 2:4 +h 4096 -sbdt nnts -pa ebin" ./test/example-problem.es
0 :: 1.96s
10 :: 1.95s
1000 :: 1.87s
10000 :: 3.32s
100000 :: 19.28s
1000000 :: 182.78s
and, just to be sure again with Erlang's file module and all available cores enabled:
ERL_FLAGS="-S 4:4 +h 4096 -sbdt nnts -pa ebin" ./test/example-problem.es
0 :: 1.96s
10 :: 1.87s
1000 :: 1.81s
10000 :: 3.18s
100000 :: 19.31s
1000000 :: 178.06s