• Matthew Wilson (46/46) Apr 12 2003 I'm doing a performance analysis, part of which involves the creation of

"Matthew Wilson" <matthew stlsoft.org> writes:

I'm doing a performance analysis, part of which involves the creation of
instances of an auto class within the inner loop, in order to test D wrt
resource contention.

It looks like this.

int worker_proc(void *_arg)
{
    ThreadInfo  threadinfo  =   (ThreadInfo)(_arg);
    int         i;

    threadinfo.result = 0;

    for(i = 0; i < threadinfo.cIterations; ++i)
    {
        auto XUser  user = new XUser;           // Acquire the resource

        // Do stuff here - calculating pi, actually
    }

    return 0;
}

This works fine for up to about 32000 iterations, above which it chokes and
the process hangs. I originally suspected it was the operations of XUser()
and ~XUser(), which internally lock and unlock a semaphore - will be added
to the next release of the SynSoft D libs, if anyone's interested
(http://synsoft.org/d.html). So I took out the semaphore calls, in other
words the creation/destruction of XUser instances does nothing in
particular. This still hangs

The next idea was to change XUser (now not locking the semaphore, remember)
to not be an auto class, and to remove the auto keywordfs

    for(i = 0; i < threadinfo.cIterations; ++i)
    {
        XUser  user = new XUser;           // Acquire the resource

Still hangs. Next I decided to forget XUser for a while, and replaced it
with an instance of X - X is defined as class X{}

    for(i = 0; i < threadinfo.cIterations; ++i)
    {
        X           x   =   new X;

Still hangs! Finally, I replaced it with instance of Object

    for(i = 0; i < threadinfo.cIterations; ++i)
    {
        Object o   =   new Object;

Still hangs!!

This may be a GC problem, but I was under the impression that auto objects
were on the stack, and this started when XUser was an auto class/instance.
If auto go on the heap, then it simply looks like the GC has a limit. If
autos don't go on the GC, then I have no idea.

Either way it's pretty terminal.

Fix, perchance ... ??

:)

Matthew