Re: memory leak in constructor and during object creation

From:

=?ISO-8859-1?Q?Marcel_M=FCller?= <news.5.maazl@spamgourmet.com>

Newsgroups:

comp.lang.c++

Date:

Mon, 29 Sep 2008 09:53:36 +0200

Message-ID:

<48e089cb$0$6567$9b4e6d93@newsspool4.arcor-online.net>

raj s schrieb:

Will the below code cause memory leak in c++

Yes. All pointer objects will never be destroyed, since your programm
does not provide a delete statement.

class base{
    int a;
    int *pint;
    someclass objsomeclass;
    someclass* psomeclass;
    base(){
        objsomeclass = someclass();
        psomeclass = new someclass();
        pint = new int();
        throw "constructor failed";
        a = 43;
    }
}
main(){
    base temp();
}

in the above code constructor fails.Which objects will be leaked and
how to avoid memory leak

Use smart pointers.

> and even if destructor is called for

automatic object is temp and temp pointer will leak the memory?

The destructor will not be called if the constructor fails. But the
destructor for a successfully constructed base members is called -
normally. In your case, you do not catch your exception. That usually
causes a call to abort(), which will end your programm immediately
without any cleanup. From that point it is up to the operating system to
do the cleanup.

main(){
base *temp = base();
}

what about in the above code and how to avoid memory leak when
constructor fails

The memory of base is normally freed in this case, since no object is
successfully constructed. But again, you must catch your exception to
prevent your programm from an immediate abort.

Marcel