We have used this code:
data = Base.encode64(:crypto.strong_rand_bytes(2_000_000))
Mix.Tasks.Profile.Tprof.profile(
fn -> inspect(data, printable_limit: :infinity) end,
type: :memory
)
The first result reported this:
Profile results of #PID<0.106.0>
# CALLS % WORDS PER CALL
Total 10666685 100.00 9268308211 868.90
:code.ensure_loaded/1 1 0.00 3 3.00
Inspect.BitString.inspect/2 1 0.00 4 4.00
Inspect.Algebra.group/2 1 0.00 4 4.00
Inspect.Algebra.format/2 1 0.00 6 6.00
Inspect.Algebra.format/3 3 0.00 8 2.67
:erlang.iolist_to_binary/1 2 0.00 11 5.50
anonymous fn/2 in Kernel.struct/2 1 0.00 17 17.00
Inspect.Opts.new/1 1 0.00 17 17.00
Code.Identifier.escape/5 2666669 0.06 5333344 2.00
String.recur_printable?/2 2666669 0.29 26666778 10.00
Code.Identifier.escape_map/1 2666668 28.72 2662035405 998.26
Code.Identifier.escape_char/1 2666668 70.93 6574272614 2465.35
As you can see, most of the allocations were in escape_char,
which makes sense: it will be invoked a lot for raw binaries
and it allocated lists, instead of relying on binary optimizations.
We reimplemented Code.Identifier.escape/5 to rely on binary
optimizations which then yielded this:
Profile results of #PID<0.112.0>
# CALLS % WORDS PER CALL
Total 5333350 100.00 26666864 5.00
:code.ensure_loaded/1 1 0.00 3 3.00
Inspect.BitString.inspect/2 1 0.00 4 4.00
Inspect.Algebra.group/2 1 0.00 4 4.00
Inspect.Algebra.format/2 1 0.00 6 6.00
Code.Identifier.escape/4 1 0.00 8 8.00
Code.Identifier.escape/5 2666669 0.00 8 0.00
Inspect.Algebra.format/3 3 0.00 8 2.67
:erlang.iolist_to_binary/1 2 0.00 11 5.50
anonymous fn/2 in Kernel.struct/2 1 0.00 17 17.00
Inspect.Opts.new/1 1 0.00 17 17.00
String.recur_printable?/2 2666669 100.00 26666778 10.00
Now the allocations are all on `recur_printable?/2`. By running this
command, we can find out why it is allocating so much:
ERL_COMPILER_OPTIONS=bin_opt_info elixir lib/elixir/lib/string.ex
It happens that, due to a catch all, new binary contexts had to be
allocated. By addressing that, we now get:
Profile results of #PID<0.119.0>
# CALLS % WORDS PER CALL
Total 5333350 100.00 91 0.00
:code.ensure_loaded/1 1 3.30 3 3.00
Inspect.BitString.inspect/2 1 4.40 4 4.00
Inspect.Algebra.group/2 1 4.40 4 4.00
String.recur_printable?/2 2666669 5.49 5 0.00
Inspect.Algebra.format/2 1 6.59 6 6.00
Code.Identifier.escape/4 1 8.79 8 8.00
Code.Identifier.escape/5 2666669 8.79 8 0.00
Inspect.Algebra.format/3 3 8.79 8 2.67
:erlang.iolist_to_binary/1 2 12.09 11 5.50
anonymous fn/2 in Kernel.struct/2 1 18.68 17 17.00
Inspect.Opts.new/1 1 18.68 17 17.00
Which is several orders of magnitude fewer words. We basically
allocate the new escaped binary and a few extra bytes.
Closes#14029.
The typos were detected by this app: https://pypi.org/project/typos/
running the following command
typos --exclude "lib/elixir/unicode/" --exclude "man/" --exclude "typos" --format brief
Previously, the example contained 2 issues.
1. A syntax error on `receive` as there were no parens.
2. The example was incomplete, and would hang on the 2nd receive
This commit updates the example to reflect the original intent, by
sending 2 messages and getting a `:noproc` on the 2nd `receive`.
In theory we need to check if the function does not have
an environment but the goal of the check is not to be precise,
but rather to catch obvious mistakes.
José Valim
Jonatan Kłosko
Michał Łępicki
Mathias Polligkeit
Jean Klingler
Panagiotis Nezis
Leif Metcalf
Ray Chang
Theodor Fiedler
Eksperimental
maintenance-beam-app
Christopher Keele
Gary Rennie
Dave Lucia
Tobias Pfeiffer
Guillaume Duboc
Theodor Fiedler