memory leak or something wrong

[Brandon Black]

On Mon, Jun 18, 2012 at 12:43 AM, yao liufeng <ylfroy at 163.com> wrote:
> can someone help to clarify whether it's a
> memory leak or something wrong with the code? Thanks!

Googling around, it seems like in the past year or two there's been
some flareup between C99/C1X, POSIX, and glibc about interpretations
of what the right/acceptable/conforming behavior of realloc(p,0) is:

http://austingroupbugs.net/view.php?id=400
http://sourceware.org/bugzilla/show_bug.cgi?id=12547

In practice, on Fedora 16 (glibc 2.14), I've observed a very small
leak on code like yours (you can even leave libev out of this, it's
all about alloc/dealloc cycles using only the realloc() interface),
which is fixable by replacing realloc(p,0) calls with free(p).  libev
already works around realloc(p,0) on non-glibc targets, it may just
have to not use realloc(p,0) anywhere now as the simplest solution.
You can test for yourself whether that's the issue by doing something
like:

void* my_realloc(void* ptr, long size) {
    if(size)
        return realloc(ptr, size);
    free(ptr);
    return 0;
}
ev_set_allocator(my_realloc);

-- Brandon