Re: [Boost-users] Are memory leaks reported by Boost.Test Microsoft Memory Leak Detection Enabling spurious or real?

Subject: Re: [Boost-users] Are memory leaks reported by Boost.Test Microsoft Memory Leak Detection Enabling spurious or real?
From: Paul A. Bristow (pbristow_at_[hidden])
Date: 2010-10-28 09:44:23

> -----Original Message-----
> From: boost-users-bounces_at_[hidden] [mailto:boost-users-
> bounces_at_[hidden]] On Behalf Of Gennadiy Rozental
> Sent: Thursday, October 28, 2010 2:03 PM
> To: boost-users_at_[hidden]
> Subject: Re: [Boost-users] Are memory leaks reported by Boost.Test
Microsoft
> Memory Leak Detection Enabling spurious or real?
> 
> Paul A. Bristow <pbristow <at> hetp.u-net.com> writes:
> 
> > But no filename is given as promised by
> > http://msdn.microsoft.com/en-us/library/e5ewb1h3%28v=VS.80%29.aspx
> 
> You need special macro defined in your code. Read the page for details.

I've added this at the head of the test file.cpp

#define _CRTDBG_MAP_ALLOC
#include <stdlib.h>
#include <crtdbg.h>

which promises

"With _CRTDBG_MAP_ALLOC defined, the display also shows you the file where
the leaked memory was allocated. The number in parentheses following the
file name (20, in this example) is the line number within the file."

But there is no filename or line number :-(

(but the line
{3485} normal block at 0x004811B0, 42 bytes long.
   Data: <class boost::mat> 63 6C 61 73 73 20 62 6F 6F 73 74 3A 3A 6D 61 74

looks as though it is the start of boost::math  - of which (since this IS
Boost.Math)  there are zillion references;-)

And these look like floating point template parameters...

{2536} normal block at 0x00483530, 12 bytes long.
   Data: <long double > 6C 6F 6E 67 20 64 6F 75 62 6C 65 00 
  {1587} normal block at 0x004834C0, 7 bytes long.
   Data: <double > 64 6F 75 62 6C 65 00 
  {637} normal block at 0x004831E8, 6 bytes long.
   Data: <float > 66 6C 6F 61 74 00

So I'm still puzzled if/where I should look for a problem.

> > Or is this spurious?  Should I just suppress the warnings?
> 
> Most probably it's real (unless you are using some third party software,
which
> has leaks you can ignore).

Pure Boost!  (and no messing with malloc or pointers (by me)).

Paul

PS Curiously, if I add the #define _CRTDBG_MAP_ALLOC etc to an example file
(not using Boost.Test),
that calls the function that caused the reports to start, I don't get any
leak reports (using debug mode).

PPS

typeid(MyType).name(); http://support.microsoft.com/kb/140670/en-gb

Which sounds plausible, but it is way out of date, so does it still apply to
VC10?

I'm not using typeid myself (but I suspect it is used elsewhere in
Boost.Math - if not Boost.Test!).

---
Paul A. Bristow,
Prizet Farmhouse, Kendal LA8 8AB  UK
[phone]  07714330204
pbristow_at_[hidden]