From: Petter A. Urkedal <paurkedal@gmail.com>
Date: Tue, 30 Oct 2018 20:00:32 +0000 (+0100)
Subject: Fix marks and hb_n_marks consistency when disclaim returns true
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3a5da5e6c7d336c616bf7e42fb4c56b24fc139ec;p=gc

Fix marks and hb_n_marks consistency when disclaim returns true

* reclaim.c [ENABLE_DISCLAIM] (GC_disclaim_and_reclaim): When a
disclaim callback returns 1 to protect an object from being reclaimed,
mark it to skip it on repeated scans within the cycle. In particular,
this fixes sz*hhdr->hb_n_marks<=HBLKSIZE assertion failure due to
excessive increments of hb_n_marks.
---

diff --git a/reclaim.c b/reclaim.c
index f729f5d5..ac92e058 100644
--- a/reclaim.c
+++ b/reclaim.c
@@ -238,6 +238,7 @@ STATIC ptr_t GC_reclaim_uninit(struct hblk *hbp, hdr *hhdr, word sz,
     while ((word)p <= (word)plim) {
         int marked = mark_bit_from_hdr(hhdr, bit_no);
         if (!marked && (*disclaim)(p)) {
+            set_mark_bit_from_hdr(hhdr, bit_no);
             hhdr -> hb_n_marks++;
             marked = 1;
         }