Re: Singleton_pattern and Thread Safety
On 14/12/2010 22:14, Ian Collins wrote:
On 12/15/10 11:02 AM, Leigh Johnston wrote:
On 14/12/2010 21:59, Ian Collins wrote:
On 12/15/10 10:55 AM, Joshua Maurice wrote:
On Dec 14, 11:01 am, Leigh Johnston<le...@i42.co.uk> wrote:
On 14/12/2010 18:59, Ian Collins wrote:
On 12/15/10 04:42 AM, Leigh Johnston wrote:
Kanze's method to create the singletons before main() was to avoid
threading issues (which is what the OP wants). Kanze's method is
leaky
and has unspecified construction order, end of.
It is not leaky in any of the situations I have used it.
If the singleton is not deleted on program exit then it is a leak.
You will be wrong as long as you use that definition and assert it's
bad a priori. The rest of us program to business requirements and use
cases, and "avoid a Leigh Johnston memory leak at all costs" has never
been a real business requirement nor use case.
Especially when the memory isn't leaked! It's in use and accessible
until the process terminates.
It is a leak. If it wasn't a leak the OS wouldn't have anything to
deallocate during process cleanup.
To cite your own reference source:
http://en.wikipedia.org/wiki/Memory_leak
"A memory leak, in computer science (or leakage, in this context),
occurs when a computer program consumes memory but is unable to release
it back to the operating system."
From the same source:
"Leaks that are much more serious include:
where running on operating systems where memory may not be automatically
released on termination"
Which includes singular leaks.
As far as the operating system is concerned there is no difference
between the following two leaks (and they are both leaks):
^^
int* p;
int main()
{
p = new int();
}
^^
int main()
{
int* p = new int();
}
^^
In both cases the operating system has to deallocate the allocation
during process cleanup.
You are starting to seem like a tedious troll.
/Leigh
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