== Quote from Jerry Quinn ([email protected])'s article
> Timon Gehr Wrote:
> > On 09/12/2011 07:23 PM, Jerry Quinn wrote:
> > > I'm looking at porting an app that maintains a work queue to be processed
> > > by
one of N engines and written out in order. At first glance, std.parallelism
already provides the queue, but the Task concept appears to assume that there's
no
startup cost per thread.
> > >
> > > Am I missing something or do I need to roll a shared queue object?
> >
> > I don't know if I get you right, but std.parallelism uses a task pool.
> > Usually no threads are started or stopped during processing.
> OK I guess what I'm looking for is WorkerLocalStorage. I can create an engine
per thread. However, I probably need to have each thread do the initialization
work. If I create the engine on the main thread, it won't be properly accessed
by
the worker thread, right? I.e. I need each thread to run engine.init() which
will
do a whole pile of loading and setup first before I can start feeding data to
the
pool.
> The impression I get is that
> for (int i=0; i < nthreads; i++)
> taskPool.workerLocalStorage(new engine(datafile))
> will not get me what I want.
The parameter for taskPool.workerLocalStorage is lazy, so it's even easier:
taskPool.workerLocalStorage(new engine(datafile));
will create one new engine **per thread** because the lazy parameter is passed
to
it and evaluated **once per thread**. I'm not sure what an engine is in this
context, though.
As far as initialization, you could do something like:
auto isInitialized = taskPool.workerLocalStorage(false);
void doStuff() {
if(!isInitialized.get) {
engines.get.initialize();
isInitialized.get = true;
}
// Do some real processing.
}
