Could you add this code that you (Ivan) gave me in June 2014 about bdwgc HOT 3 CLOSED

I was mistaken, it was Peter Wang who posted the code in this message:

Message: 4
Date: Fri, 6 Jun 2014 14:16:27 +1000
From: Peter Wang [email protected]
To: Christian Schafmeister [email protected]
Cc: [email protected]
Subject: Re: [Gc] Is there a way to walk the entire heap of live
objects
Message-ID: [email protected]
Content-Type: text/plain; charset=utf-8

On Thu, 05 Jun 2014 07:57:53 -0400, Christian Schafmeister [email protected] wrote:
Hi there,

Is there any functionality in the Boehm GC that would allow me to
freeze the garbage collector and walk the heap of live objects? I?d
like to take an inventory of all of the live objects to determine the
source of my current memory problems (30 GB of virtual memory used
after 4 hours of runtime).

Hi,

We do something like that in the Mercury project using the following
function.

I am not an expert on Boehm GC internals, and the code is only used in a
special memory profiling grade, so not heavily exercised.
Please let me know if there is something wrong with it.

Peter

(in reclaim.c)

STATIC void GC_mercury_do_enumerate_reachable_objects(struct hblk *hbp,
word dummy)
{
struct hblkhdr * hhdr = HDR(hbp);
size_t sz = hhdr -> hb_sz;
size_t bit_no;
char *p, *plim;

if (GC_block_empty(hhdr)) {
return;
}

p = hbp->hb_body;
bit_no = 0;
if (sz > MAXOBJBYTES) { /* one big object /
plim = p;
} else {
plim = hbp->hb_body + HBLKSIZE - sz;
}
/ Go through all words in block. */
while (p <= plim) {
if (mark_bit_from_hdr(hhdr, bit_no)) {
GC_mercury_callback_reachable_object((GC_word *)p,
BYTES_TO_WORDS(sz));
}
bit_no += MARK_BIT_OFFSET(sz);
p += sz;
}
}

GC_INNER void GC_mercury_enumerate_reachable_objects(void)
{
GC_ASSERT(GC_mercury_callback_reachable_object);
GC_apply_to_all_blocks(GC_mercury_do_enumerate_reachable_objects, (word)0);
}

from bdwgc.

please make a pull request

from bdwgc.

I made a pull request

from bdwgc.