Condition variables?

[Sean Kelly]

David Brown wrote:
> Hopefully I'm missing something obvious here, but D and phobos seem to
> be missing any kind of condition variables.  It's really hard to do
> non-trivial thread programming without this kind of synchronization.
> 
> In fact, I'm not sure how I could even go about implementing
> something, since there doesn't seem to be any way of easily accessing
> the object's monitor, which would be needed to do condition variables
> that work with 'synchronized'.

Tango has them in tango.core.sync.Condition.  They need to work with 
Tango's mutexes (tango.core.sync.Mutex), and those mutexes work with 
'synchronized':

auto   m = new Mutex;
auto   c = new Condition;
data[] d;

// thread A
synchronized( m )
{
     while( d.length == 0 )
         c.wait();
     // use data
}

// thread B
synchronized( m )
{
     d ~= something;
     c.notify();
}


Sean