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Postings from February 2001
Hong Zhang wrote: > That was not what I meant. Your code already assume the existence of > reference counting. It does not work well with any other kind of garbage > collection. If you translate the same code into C without putting in > the close(), the code will not work at all. Wrong, it does *not* assume any such thing. It assumes that when a filehandle goes out of scope it is closed. How that is achieved is a detail of the implementation, and could be done in a number of ways. It could just as well be done by keeping the filehandle on a stack which was cleared when the scope exits. C++ does this for local variables without requiring a refcount. > By the way, in order to use perl in real native thread systems, we have > to use atomic operation for increment/decrement reference count. On most > systems I have measured (pc and sparc), any atomic operation takes about > 0.1-0.3 micro second, and it will be even worse on large SMP machines. > The latest garbage collection algorithms (parallel and cocurrent) can > handle large memory pretty well. The cost will be less DF. I think you'll find that both GC *and* reference counting scheme will require the heay use of mutexes in a MT program. Alan BurlisonThread Previous | Thread Next