On Saturday, 3 January 2015 at 22:10:49 UTC, Vlad Levenfeld wrote:
On Saturday, 3 January 2015 at 15:44:16 UTC, Matt wrote:
Right, I've been looking at core.atomic, but it has very
little documentation, and it's territory I haven't explored,
yet. Any chance of some pointers along the way?
Could you be more specific about what you need help
understanding? You can implement a very simple double buffer
like so:
synchronized final class DoubleBuffer (T) {
T[][2] data;
uint write_index;
shared void swap () {
atomicStore (write_index, (write_index + 1) % 2);
(cast()this).buffer[write_index].clear;
}
shared @property write_buffer () {
return (cast()this).buffer[write_index][];
}
shared @property read_buffer () {
return (cast()this).buffer[(write_index + 1) % 2][];
}
}
Just append to write_buffer, call swap, then read from
read_buffer. Make sure you declare the instance shared.
Benjamin's post links to a more robust and realistic
implementation.
What I mean is that I don't understand what atomicStore,
atomicLoad, etc. actually DO, although in the case of the two
mentioned, I can hazard a pretty good guess. The documentation
doesn't exist to tell me how to use the functions found in the
module. I've never used any atomic functions in any language
before.
However, thank you for the simple double buffered example, I do
appreciate it. How would another thread gain access to the
instance in use, though? Am I able to pass references to
instances of this class via events? 'synchronized' is also
something I'm clueless about, and again the D documentation
doesn't help, as the section in the class documentation basically
says "synchronized classes are made of synchronized functions",
without explaining what a synchronized function IS. The function
section makes no mention of the synchronized keyword, either.
Sorry, it feels like there's a load of stuff in the library and
language to make multithreading easier, but with little to no
explanation, so it feels like you're expected to already know it,
unless I'm looking in the wrong places for my explanations. If I
am, please do give me a kick, and point me in the right direction.
