Strange memory leak

[miniman06]

//process.h
private:
PROCESSENTRY32 * m_proc;
char * m_filename;
bool m_stringupdated;

//process.cpp
Process::Process()
{
m_proc = new PROCESSENTRY32;
m_proc->dwSize = sizeof(PROCESSENTRY32);
m_stringupdated = false;
m_filename = NULL;
}
//process.cpp
Process::~Process()
{
delete m_proc;
if(m_filename)
delete [] m_filename;
}

//main
Process * allo = new Process();
allo->~Process();

VLD reports:

Visual Leak Detector Version 2.2.3 installed.
WARNING: Visual Leak Detector detected memory leaks!
---------- Block 1 at 0x005A2100: 12 bytes ----------
Call Stack:
c:\users\jean\documents\visual studio 2012\projects\procenum\procenum\procenum.cpp (26): ProcEnum.exe!wmain + 0x7 bytes
f:\dd\vctools\crt_bld\self_x86\crt\src\crtexe.c (533): ProcEnum.exe!__tmainCRTStartup + 0x19 bytes
f:\dd\vctools\crt_bld\self_x86\crt\src\crtexe.c (377): ProcEnum.exe!wmainCRTStartup
0x760A33AA (File and line number not available): kernel32.dll!BaseThreadInitThunk + 0x12 bytes
0x76CF9EF2 (File and line number not available): ntdll.dll!RtlInitializeExceptionChain + 0x63 bytes
0x76CF9EC5 (File and line number not available): ntdll.dll!RtlInitializeExceptionChain + 0x36 bytes
Data:
48 21 5A 00 00 00 00 00 00 CD CD CD H!Z..... ........

Visual Leak Detector detected 1 memory leak (48 bytes).
Largest number used: 640 bytes.
Total allocations: 640 bytes.
Visual Leak Detector is now exiting.
The program '[10680] ProcEnum.exe' has exited with code 0 (0x0).

I'm freaking out guys I just don't see the leak ,Thanks in advance :) .

[Sivaraman Dhamodharan]

How many bytes allocated and pointed by m_filename?

Programming Article

[Rolf Kristensen]

If the sizeof(PROCESSENTRY32) == 48, then I have found your leak.

[miniman06]

it's not used ,its deallocating it anyway...

[miniman06]

not that either it's around 500~ bytes and I'm deallocating that too :/

[Santhosh G_]

I cant see any memory leak in the given code.

//main.. comment out the below code
// Process * allo = new Process();
//allo->~Process();

Please check memory leak without allocating memory Process.

[miniman06]

Visual Leak Detector Version 2.2.3 installed.
No memory leaks detected.
Visual Leak Detector is now exiting.
The program '[9248] ProcEnum.exe' has exited with code 0 (0x0).

Not a false positive.

[Jochen Arndt]

You are explicitly calling the destructor. This will free the allocated memory for the members but not the object itself. You should use delete instead:

delete allo;

Or you may use auto delete (using an additional member var):

Process::~Process()
{
delete m_proc;
if(m_filename) // this is not necessary
delete [] m_filename;
if (m_bAutoDelete)
delete this;
}

[miniman06]

that pretty much solved me the problem something to note delete still calls the destructor. so the auto delete code that you provided will cause an exception.

Process::~Process()
{
if(m_bDeallocated)
return;

delete m\_proc;
delete \[\] m\_filename;
m\_bDeallocated = true;
if (m\_bAutoDelete)
    delete this; //will call this destructor again and cause trouble

}

[Jochen Arndt]

Yes, you are right. That would result in a recursion. My code lacks resetting the m_bAutoDelete variable. It must be:

Process::~Process()
{
if (m_bAutoDelete)
{
m_bAutoDelete = false;
delete this;
}
else
{
delete m_proc;
delete [] m_filename;
m_proc = NULL;
m_filename = NULL;
}
}

However, this is not a good solution because the destructor is called twice and this will fail if the object wasn't allocated using new.

[BCN 163]

thank you and the reply, I learned something for this question. thanks again!