On Sunday June 6 2010, David Sugar wrote:
> I have added new create() methods to the reusable pool templates so it
> can return pre-constructed (initialized) objects. I also found a bug
> internal to queueof lifo method and changed the templates for queueof
> and stackof so that the pool is passed to the constructor rather than in
> the template (linkage requirement issue). Finally, I added an initial
> unit test case, ucommonQueue (test/queue.cpp) which both demonstrates
> the use case and validates at least some basic funcions of the current
> implementation. The unit test case code should be expanded upon to try
> and identify any additional bugs or issues.
David,
I downloaded the SVN head - the problem 1 from the letter below still exists.
I also do not see that file queue.cpp is compiled by the tests.
May be I use incorrect SVN?
svn co svn://svn.sv.gnu.org/commoncpp/trunk/ucommon
Thanks.
>
> On 06/05/2010 03:51 PM, Leon Pollak wrote:
> > On Saturday June 5 2010, David Sugar wrote:
> >> First, the queue core class can use a reusable pool, but this is for
> >> internal management of it's own pointers. The queue is passed an object
> >> to post into it that is derived from "Object", which are reference
> >> counted. Hence, existing on the queue is actually a reference count
> >> instance of a reference counted object. However, if you want a resuable
> >> pool of buffer objects, you would construct an object for your buffer
> >> that is itself derived from ReusableObject (which is derived from
> >> Object), and this is what you would then pass into the queue.
> >>
> >> Hence maybe you would use something like:
> >>
> >> class MyObject : public ReusableObject
> >> {
> >>
> >> public:
> >> char data[100];
> >>
> >> };
> >>
> >> static mempager datapool;
> >>
> >> // we have a pool with a maximum allocation size of 100 objects...
> >> static paged_reuse<MyObject> bufpool(&datapool, 100);
> >>
> >> // and a fixed size stream buffer of referenced objects...
> >> static queueof<MyObject> mycache(&datapool, 10);
> >>
> >> // we have a cache for these 100 objects...
> >>
> >> to post:
> >> // timeout to try
> >> MyObject *x = bufpool.get(100);
> >>
> >> // on error getting a new pool object...
> >> if(!x) ... we could allocate from datapool, throw, whatever...
> >>
> >> // we may also need to add x->retain(), it's been awhile....
> >>
> >> // make sure it survives cache...
> >> String::set(x->data, 100, "something");
> >>
> >> // timeout possible...
> >> if(!mycache.post(x, 100)) ... failed to post ...
> >>
> >> to get an object from the queue:
> >> // with a timeout...
> >> MyObject *x = mycache.lifo(100);
> >>
> >> if(!x) ... we didn't get anything before timer expired...
> >>
> >> printf("data %s\n", x->data);
> >>
> >> // release object back to reuse pool...
> >> bufpool::release(x)
> >
> > Hello David,
> >
> > And again thanks for the example.
> >
> > It seems you were right - no use of the queue/queueof was not tried
> > yet...:-)
> >
> > 1. I tried to compile the example you provided above. There is a problem
> > with the second template parameter of queueof - it cannot be
> > null-pointer according to my search in the internet. See for example
> > http://stackoverflow.com/questions/1418019/casting-pointer-as-template-
> > argument-comeau-msvc-compile-gcc-fails
> >
> > 2. You declared all three objects as 'static', which, besides the
> > problems with compilation also makes them invisible from the outside,
> > no? This forces me to put both threads in the same file, which is not
> > good for me. What was your reason to declare them static?
> >
> > Thanks.
--
Dr.Leon M.Pollak
Director
PLR Information Systems Ltd.
Tel.:+972-98657670 | POB 8130, H'Aomanut 9,
Fax.:+972-98657621 | Poleg Industrial Zone,
Mob.:+972-544739246 | Netanya, 42160, Israel.
_______________________________________________
Bug-commoncpp mailing list
Bug-commoncpp@gnu.org
http://lists.gnu.org/mailman/listinfo/bug-commoncpp
