Re: resource leak in destructor?
On 10 Okt., 06:38, George <Geo...@discussions.microsoft.com> wrote:
Hi Victor,
Generally, my question is if the class member has destructor, even if
- we do not call it exeplicitly in the whole class's destructor;
- or because of exception execution flow, it is not executed
its destructor will be called when the current object instance destructs?
I'm not sure what you mean exactly by above question. Here are some
facts about C++ that you should keep in mind:
- Although the C++ language doesn't forbids it, you should never throw
exceptions from your destructors. If you use libraries whose objects
throw exceptions in their destructors, consider the library broken and
ask for a fix.
- The destructors of every member is automatically invoked when the
destructor of the
object has finished (of course, unless the destructor throws an
exception. In this case the members won't get destructed). Note that
there is a big difference between smart pointer members and ordinary
pointer members: The smart pointer member will delete the contained
pointer and thus invoke the destructor of the member object. The
destructor of ordinary pointers will do nothing (this is the main
source of memory leaks).
class Goo;
class Zoo;
class Foo
{
Goo* pG;
Zoo* pZ;
// destructor
virtual ~Foo()
{
try
{
// free some resources, b=
ut the operation may throw exception
// if exception is thrown=
in function FreeResources, delete pG and delete
pZ
// will not be executed, =
are there any leak?
FreeResources();
delete pG;
delete pZ;
If FreeSources throws an exception, the members pG and pZ won't be
deleted and pG's and pZ's destructor won't get called. Better use
smart pointers.
}
catch (...)
{
}
}
}
regards,
George