[erlang-questions] Why is erlc so quick to start?

[Loïc Hoguin]

On 01/06/2015 11:13 AM, Tuncer Ayaz wrote:
> On Tue, Jan 6, 2015 at 12:06 AM, Loic Hoguin wrote:
>> Yes that also adds to the load time, but it probably wouldn't be too
>> noticeable if erlc was loading only the modules it requires instead
>> of everything. I don't think it uses the network code, dets, process
>
> It can use the network code if code is not loaded from disk. Erlang's
> distributed nature is the reason for some indirection you tried to
> circumvent in, for example, file operations :).

But erlc only compiles *files* doesn't it? It doesn't start distribution 
or anything so there should be no indirection?

>> groups and so on, and it may also not need the whole OTP application
>> framework.
>>
>> I will play with generating a smaller boot file when I get the time
>> and see what happens. If it can be made closer to 0s this would
>> allow me to just use %.erl: %.beam rules, something that's been on
>> my wishlist from the start.
>
> Maybe the resulting boot file can be used for escript as well.

Well "escript" wouldn't be part of the boot file if erlc doesn't need 
it, so my guess is no. :-)

The hard part is figuring out what it actually needs.

> Also, the speedups we've discussed also apply to older versions and
> are not fixing the overhead introduced between R13 and now. So, if
> you're serious about this, and want to invest time, I'd suggest to
> profile R13 against R14 and R15 with your trace/profile tool of choice
> and see where time in (mostly) C and maybe Erlang is spent since >=R14.

I wish I could invest time now but this and the boot file experiment 
will probably have to wait for a while.

-- 
Loïc Hoguin
http://ninenines.eu