Question about G_CHILD_ADD/G_CHILD_REMOVE


#1

Am I right in understanding that if you have code like

[GFile.new(‘a’), GFile.new(‘b’).each do |file|
file.read_async{ |contents| p contents }
end

will be fine even though #read_async is using code like

G_CHILD_ADD(mGLib, block);

G_CHILD_REMOVE(mGLib, block);

where block is generated by rb_block_proc()? I mean, rb_block_proc()
gives me a new proc for each invocation that has a unique hash, right?

Sorry about all these questions that probably have pretty obvious
answers, but I’m really managing to confuse myself with this.


#2

Hi,

In removed_email_address@domain.invalid
“[ruby-gnome2-devel-en] Question about G_CHILD_ADD/G_CHILD_REMOVE” on
Thu, 26 Mar 2009 19:38:32 +0100,
Nikolai W. removed_email_address@domain.invalid wrote:

G_CHILD_REMOVE(mGLib, block);

where block is generated by rb_block_proc()? I mean, rb_block_proc()
gives me a new proc for each invocation that has a unique hash, right?

Yes. But please use G_CHILD_* with an instance not
mGLib. It’s enough that a callback block is associated with
just an instance. Lifetimes of a callback block and an
instance are same.

Thanks,

kou


#3

On Fri, Mar 27, 2009 at 14:01, Kouhei S. removed_email_address@domain.invalid wrote:

end
Yes. But please use G_CHILD_* with an instance not
mGLib. It’s enough that a callback block is associated with
just an instance. Lifetimes of a callback block and an
instance are same.

Yes, that was my initial thought as well. However, doing that will
complicate the code quite a bit. At the moment I simply pass the
block as the user_data to the async functions. If I associate it with
self I’ll have to pass in an allocated struct (or similar) containing
both self and the block, right?

Or can I do something like the following?

static void
read_async_callback(GObject *source, GAsyncResult *result, gpointer
data)
{
VALUE block = (VALUE)data;
â‹®
if (NIL_P(block))
return;

G_CHILD_REMOVE(GOBJ2RVAL(source), block);
rb_funcall(block, g_id_call, …);
}

static VALUE
read_async(int argc, VALUE *argv, VALUE self)
{
â‹®
VALUE block;
â‹®
rb_scan_args(argc, argv, “…&”, …, &block);
if (!NIL_P(block))
G_CHILD_ADD(self, block);
â‹®
g_file_read_async(_SELF(self), …, read_async_callback, &block);
â‹®
}

That is, will self and GOBJ2RVAL(source) be the same VALUE? If I
understand GOBJ2RVAL correctly they won’t. Is there a way of getting
“self” in read_async_callback?

(I know that _SELF(self) and source are the same.)

Thanks.