Re: Singleton_pattern and Thread Safety

James Kanze <>
Thu, 16 Dec 2010 02:56:37 -0800 (PST)
On Dec 15, 5:26 pm, gwowen <> wrote:

On Dec 15, 5:15 pm, Leigh Johnston <> wrote:

How the OS handles a leak is irrelevant to the issue of whether it is a
leak. The definition of what constitutes a leak transcends all
operating systems. A leak is an explicit allocation that does not have
a matching explicit deallocation.

So you keep saying. And Microsoft seem to agree with you. But Apple
don't. Apple say its an allocation to which you no longer have a

And most practicing programmers use a more useful definition
than either: a leak is an allocation pattern which causes
unbounded memory use. The fact that there is still a pointer to
the memory doesn't stop it from being a leak, if you never use
the memory, and are constantly allocating new memory.

"A software bug is the common term used to describe an error, flaw,
mistake, failure, or fault in a computer program or system *that
produces an incorrect or unexpected result, or causes it to behave in
unintended ways*" - Wikipedia, again.

Yes and a leak is a bug according to that definition

Really? In those cases where the OS reclaims memory at process
termination, what is the incorrect or unexpected result or unintended

A leak is a bug according to that definition. The problem is
that Leigh (and you, apparently) have redefined leak in a way
that it isn't a bug. (Unbound memory use is a bug. Regardless
of whether you still have a pointer to the memory or not.)

James Kanze

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