[Insight-developers] Question about delete on VC++

Bill Hoffman bill.hoffman@kitware.com
Mon, 30 Sep 2002 16:11:20 -0400


I think something else is going on here...

-----foo.cxx----

struct foo
{
  virtual int b();
  ~foo();
};


struct bar : public foo
{
  ~bar();
};

Linux:
[hoffman@ringworld hoffman]$ c++ -Wall -c foo.cxx
foo.cxx:5: warning: `struct foo' has virtual functions but non-virtual destructor
foo.cxx:11: warning: `struct bar' has virtual functions but non-virtual destructor

SGI:
rolle:/rolle/insight % CC -fullwarn -LANG:std -c foo.cxx
cc-1375 CC: REMARK File = foo.cxx, Line = 8
  The destructor for base class "foo" is not virtual.

  struct bar : public foo
                      ^

cygwin:
bash-2.05$ c++ -Wall foobar.cxx
foobar.cxx:4: destructor `f' must match class name `foo'
foobar.cxx:5: warning: `struct foo' has virtual functions but non-virtual destructor
foobar.cxx:11: warning: `struct bar' has virtual functions but non-virtual destructor
bash-2.05$ c++ -v
Reading specs from /usr/lib/gcc-lib/i686-pc-cygwin/2.95.3-5/specs
gcc version 2.95.3-5 (cygwin special)





At 03:53 PM 9/30/2002 -0400, Miller, James V (Research) wrote:
>I think the warning that the compiler reports is for a
>class with a non-virtual destructor and and a subclass
>with a virtual destructor.
>
>The hierarchy here used STRUCTS as opposed to classes.
>So I guessing the compiler didn't warn about structs.
>
>
>
>> -----Original Message-----
>> From: Joshua Cates [mailto:cates@sci.utah.edu]
>> Sent: Monday, September 30, 2002 3:48 PM
>> To: Bill Hoffman
>> Cc: Miller, James V (Research); 'Jisung Kim'; insight-dev-list
>> Subject: RE: [Insight-developers] Question about delete on VC++
>> 
>> 
>> One of the builds warns about this.  I think IRIX.
>> 
>> Josh.
>> 
>> ______________________________
>>  Josh Cates                   
>>  School of Computer Science   
>>  University of Utah
>>  Email: cates@sci.utah.edu
>>  Phone: (801) 587-7697
>>  URL:   www.cs.utk.edu/~cates
>> 
>> 
>> On Mon, 30 Sep 2002, Bill Hoffman wrote:
>> 
>> > Isn't this a warning on some compilers?
>> > (Class with virutal table has non-virutal destructors?)
>> > 
>> > 
>> > -Bill
>> > 
>> > 
>> > At 03:41 PM 9/30/2002 -0400, Miller, James V (Research) wrote:
>> > >I ran the test through Purify.  This identified that a leak
>> > >occurred.  The I spent several hours trying to find why your
>> > >memory was not being deallocated.  Eventually, I put print 
>> > >statements in each node type's destructor to make sure they 
>> > >were being called.  As it turned out, the destructors were
>> > >never being called because the nodes in the kdtree store pointers
>> > >to a kdnode and kdnode did not have a destructor defined. This
>> > >meant that the compiler provided its own destructor which by
>> > >default is non-virtual.
>> > >
>> > >Jim
>> > >
>> > >
>> > >
>> > >> -----Original Message-----
>> > >> From: Jisung Kim [mailto:bahrahm@yahoo.com]
>> > >> Sent: Monday, September 30, 2002 2:16 PM
>> > >> To: Miller, James V (Research); insight-dev-list
>> > >> Subject: RE: [Insight-developers] Question about delete on VC++
>> > >> 
>> > >> 
>> > >> Thanks, Jim.
>> > >> 
>> > >> Could you tell me how did you found the memory leaks?
>> > >> I was experimenting with _CrtDumpMemoryLeaks()
>> > >> function. It would be helpful in future.
>> > >> 
>> > >> Thank you very much,
>> > >> 
>> > >> Jisung.
>> > >> 
>> > >> --- "Miller, James V (Research)" <millerjv@crd.ge.com>
>> > >> wrote:
>> > >> > Jisung,
>> > >> > 
>> > >> > I just fixed the memory leaks in your KdTree.
>> > >> > 
>> > >> > The base kd-node class did not have a "virtual"
>> > >> > destructor.  When the 
>> > >> > tree was being deleted, the destructors for "real"
>> > >> > kd-nodes was not 
>> > >> > being called.
>> > >> > 
>> > >> > Jim
>> > >> > 
>> > >> > 
>> > >> > 
>> > >> > > -----Original Message-----
>> > >> > > From: Jisung Kim [mailto:bahrahm@yahoo.com]
>> > >> > > Sent: Friday, September 27, 2002 1:53 PM
>> > >> > > To: Jisung Kim; Miller, James V (Research);
>> > >> > insight-dev-list
>> > >> > > Subject: RE: [Insight-developers] Question about
>> > >> > delete on VC++
>> > >> > > 
>> > >> > > 
>> > >> > > The print out result shows exact match between
>> > >> > > addresses of pointer (to nodes) and the order. 
>> > >> > > 
>> > >> > > 
>> > >> > > --- Jisung Kim <bahrahm@yahoo.com> wrote:
>> > >> > > > In a same thread.
>> > >> > > > 
>> > >> > > > I will do printing out address of nodes in
>> > >> > creation
>> > >> > > > and deletion in VC++ too. And let you know the
>> > >> > > > result.
>> > >> > > > 
>> > >> > > > --- "Miller, James V (Research)"
>> > >> > > > <millerjv@crd.ge.com>
>> > >> > > > wrote:
>> > >> > > > > Are those in different threads?
>> > >> > > > > 
>> > >> > > > > 
>> > >> > > > > 
>> > >> > > > > > -----Original Message-----
>> > >> > > > > > From: Jisung Kim [mailto:bahrahm@yahoo.com]
>> > >> > > > > > Sent: Friday, September 27, 2002 12:48 PM
>> > >> > > > > > To: Miller, James V (Research);
>> > >> > insight-dev-list
>> > >> > > > > > Subject: RE: [Insight-developers] Question
>> > >> > about
>> > >> > > > > delete on VC++
>> > >> > > > > > 
>> > >> > > > > > 
>> > >> > > > > > Yes, the tree was created by the
>> > >> > > > > > itkWeightedCenteroidKdTreeGenerator and the
>> > >> > > > > deletion
>> > >> > > > > > logic is inside of the itkKdTree.
>> > >> > > > > > 
>> > >> > > > > > Is it a problem?
>> > >> > > > > > 
>> > >> > > > > > Thanks,
>> > >> > > > > > 
>> > >> > > > > > 
>> > >> > > > > > --- "Miller, James V (Research)"
>> > >> > > > > <millerjv@crd.ge.com>
>> > >> > > > > > wrote:
>> > >> > > > > > > Another thought.  Is the data allocated in
>> > >> > one
>> > >> > > > > > > thread and destroyed
>> > >> > > > > > > in another thread?
>> > >> > > > > > > 
>> > >> > > > > > > 
>> > >> > > > > > > 
>> > >> > > > > > > > -----Original Message-----
>> > >> > > > > > > > From: Miller, James V (Research) 
>> > >> > > > > > > > Sent: Friday, September 27, 2002 12:07
>> > >> > PM
>> > >> > > > > > > > To: 'Jisung Kim'; insight-dev-list
>> > >> > > > > > > > Subject: RE: [Insight-developers]
>> > >> > Question
>> > >> > > > > about
>> > >> > > > > > > delete on VC++
>> > >> > > > > > > > 
>> > >> > > > > > > > 
>> > >> > > > > > > > Strange.  If we were building Dlls, I
>> > >> > would
>> > >> > > > > say
>> > >> > > > > > > that maybe we were
>> > >> > > > > > > > allocating nodes in one DLL and
>> > >> > deallocating
>> > >> > > > > them
>> > >> > > > > > > in another DLL.
>> > >> > > > > > > > (I think each DLL has its own heap
>> > >> > > > > management).
>> > >> > > > > > > But since we are 
>> > >> > > > > > > > not building DLLs, then that is not the
>> > >> > > > > problem.
>> > >> > > > > > > > 
>> > >> > > > > > > > Have you run with VC the version that
>> > >> > prints
>> > >> > > > > out
>> > >> > > > > > > all the node
>> > >> > > > > > > > allocation and deletions?
>> > >> > > > > > > > 
>> > >> > > > > > > > Is there anything "inside" a node that
>> > >> > is
>> > >> > > > not
>> > >> > > > > > > being deleted? 
>> > >> > > > > > > > Perhaps a 
>> > >> > > > > > > > subitem is missing a destructor that
>> > >> > needs
>> > >> > > > to
>> > >> > > > > do
>> > >> > > > > > > something 
>> > >> > > > > > > > that another
>> > >> > > > > > > > compiler is providing by default.
>> > >> > > > > > > > 
>> > >> > > > > > > > 
>> > >> > > > > > > > 
>> > >> > > > > > > > 
>> > >> > > > > > > > Friday, September 27, 2002 10:16 AM
>> > >> > > > > > > > > To: insight-dev-list
>> > >> > > > > > > > > Subject: [Insight-developers] Question
>> > >> > > > about
>> > >> > > > > > > delete on VC++
>> > >> > > > > > > > > 
>> > >> > > > > > > > > 
>> > >> > > > > > > > > Hi.
>> > >> > > > > > > > > 
>> > >> > > > > > > > > I have a question for memory
>> > >> > deallocation
>> > >> > > > in
>> > >> > > > > > > VC++.
>> > >> > > > > > > > > 
>> > >> > > > > > > > > Currently, my
>> > >> > > > > itkKdTreeBasedKmeansEstimatorTest
>> > >> > > > > > > is
>> > >> > > > > > > > > leaking memory on VC++ machine. It
>> > >> > seems
>> > >> > > > > like
>> > >> > > > > > > that the
>> > >> > > > > > > > > some of the k-d tree nodes has not
>> > >> > been
>> > >> > > > > deleted.
>> > >> > > > > > > > > However, On linux, it didn't have any
>> > >> > > > leak.
>> > >> > > > > I
>> > >> > > > > > > traced
>> > >> > > > > > > > > the creation and deletion of nodes by
>> > >> > > > print
>> > >> > > > > out
>> > >> > > > > > > the
>> > >> > > > > > > > > address of each nodes. And the result
>> > >> > > > shows
>> > >> > > > > > > perfect
>> > >> > > > > > > > > match between creation and deletion.
>> > >> > > > > > > > > 
>> > >> > > > > > > > > Is there anything more than calling
>> > >> > > > "delete"
>> > >> > > > > to
>> > >> > > > > > > delete
>> > >> > > > > > > > > an object. I think I read an article
>> > >> > from
>> > >> > > > MS
>> > >> > > > > > > about
>> > >> > > > > > > > > using delete and also assign zero to
>> > >> > the
>> > >> > > > > pointer
>> > >> > > > > > > to
>> > >> > > > > > > > > properly delete object in a long time
>> > >> > ago.
>> > >> > > > > Is it
>> > >> > > > > > > the
>> > >> > > > > > > > > case? Should I assign zero to the
>> > >> > pointer
>> > >> > > > > after
>> > >> > > > > > > > > calling delete?
>> > >> > > > > > > > > 
>> > >> > > > > > > > > Thank you,
>> > >> > > > > > > > > 
>> > >> > > > > > > > > 
>> > >> > > > > > > > > 
>> > >> > > > > > > > > =====
>> > >> > > > > > > > > Jisung Kim
>> > >> > > > > > > > > bahrahm@yahoo.com
>> > >> > > > > > > > > 106 Mason Farm Rd.
>> > >> > > > > > > > > 129 Radiology Research Lab., CB# 7515
>> > >> > > > > > > > > Univ. of North Carolina at Chapel Hill
>> > >> > > > > > > > > Chapel Hill, NC 27599-7515
>> > >> > > > > > > > > 
>> > >> > > > > > > > >
>> > >> > > > > > >
>> > >> > > > >
>> > >> > __________________________________________________
>> > >> > > > > > > > > Do you Yahoo!?
>> > >> > > > > > > > > New DSL Internet Access from SBC &
>> > >> > Yahoo!
>> > >> > > > > > > > > http://sbc.yahoo.com
>> > >> > > > > > > > >
>> > >> > > > >
>> > >> > _______________________________________________
>> > >> > > > > > > > > Insight-developers mailing list
>> > >> > 
>> > >> === message truncated ===
>> > >> 
>> > >> 
>> > >> =====
>> > >> Jisung Kim
>> > >> bahrahm@yahoo.com
>> > >> 106 Mason Farm Rd.
>> > >> 129 Radiology Research Lab., CB# 7515
>> > >> Univ. of North Carolina at Chapel Hill
>> > >> Chapel Hill, NC 27599-7515
>> > >> 
>> > >> __________________________________________________
>> > >> Do You Yahoo!?
>> > >> Yahoo! Health - Feel better, live better
>> > >> http://health.yahoo.com
>> > >> 
>> > >_______________________________________________
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>> > 
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>> > 
>> 
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