[syslog-ng] Per-thread scratch buffers

[Gergely Nagy]

Balazs Scheidler <bazsi at balabit.hu> writes:

> The alternative idea I was playing with was to create a new API for
> managing per-thread scratch buffers that could be reused even between
> multiple independent portions of syslog-ng.
>
> The way it would work:
>   - scratch buffers are a numbered array of GString buffers, allocated
>     for _each_ thread.

Any reason we want per-thread scratch buffers? Apart from not needing to
use a lock in this case..

As a first step in implementing this, I had something like the following
in mind:

static GTrashStack *scratch_buffers;

GString *scratch_buffer_acquite (void)
{
  GString *s;

  s = g_trash_stack_pop (scratch_buffers);
  if (!s)
    s = g_string_new (NULL);
  else
    g_string_set_size (s, 0);
  return s;
}

void scratch_buffer_release (GString *s)
{
  g_trash_stack_push (s);
}

void scratch_buffers_reset (void)
{
  GString *s;

  while ((s = g_trash_stack_pop (scratch_buffers)) != NULL)
    g_string_free (s, TRUE);
}

The expected usage is to acquire a buffer when needed, and release it
whenever we don't need it anymore.

Spice it up with some __tls_deref & similar, and we're pretty much done,
I think.

What do you think? (Meanwhile, I'll go ahead and see if this works)

-- 
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