From: Eric Wong <normalperson@...>
Date: 2017-09-08T23:50:14+00:00
Subject: [ruby-core:82721] Re: [Ruby trunk Bug#13851] getting "can't modify string; temporarily locked" on non-frozen instances

cardoso_tiago@hotmail.com wrote:
> Buffers are indeed attached per socket, but I wouldn't say
> they are short-lived. Also, I don't have guarantees that the
> same thread will handle the same socket after a wait, so I
> can't follow your advice. But I can also say that I haven't
> seen a big performance degradation because of it (although I'd
> appreciate suggestions on tools that could help me inspect
> this). 

From your original post:

  def read(io)
    io.read_nonblock(16_384, @buffer, exception: false)
    # do stuff...
    @buffer.clear
  end

It looks like @buffer only get used for the duration of the
method.

For common HTTP (and other TCP-based) servers, often you can
read an entire request with one read(2) syscall, do all parsing,
and discard the buffer ASAP (before even performing expensive
request parsing or response writing).

I only need to create a longer-lived buffer when a request is
big or trickled due to slowness.

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