phobos / tango / ares

[Charles D Hixson]

kris wrote:
> Charles D Hixson wrote:
>> I'm not sure whether you were quoting the documentation, or reporting 
>> your understanding.  If you were quoting the documentation, I think it 
>> needs editing.
> 
>  From the doc: "Please note that the class itself is stateful, and 
> therefore a single instance is not shareable across multiple threads."
> 
> Thus, it is considered unwise to share a single instance of Sprint 
> across multiple threads. However, multiple threads /can/ share a single 
> instance if they follow this pattern:
> 
> synchronized (GlobalSprint)
>               GlobalSprint ("do my formatting", with, these, args);
> 
> This is a fairly standard mechanism in D for sharing resources across 
> threads, and it's what I had referred to.
> 
> But there's no reason to do this kind of thing at all. The use-case for 
> Sprint is to keep a handy formatter around for doing fast and convenient 
> layout. Adding synchronized to the mix tends to defeat one of those 
> desirable attributes, so we don't recommend it :)
> 
> If you're content to stash layout content into a temporary buffer 
> instead, there's Formatter.sprint() which takes an output array. The 
> output array in such a case would typically be stack-based.
Mmmm...
The problem that I ran into with this before didn't involve 
multiple threads...but it did involve writing out to a file 
and to a console.  Unfortunately, It's been several months, so 
I don't remember the particulars.  The resolution, however, 
was to allocate multiple buffers within the same routine.  It 
might have involved buffering several different items within 
the same statement.  I think that may have been where things 
went wrong.  And my choices were to allocate several different 
buffers, or to break the statement into several different 
statements.

That sounds right, but don't depend on it.  As I said it's 
been several months.