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| author | Mathieu Chartier <mathieuc@google.com> | 2013-09-16 19:43:47 -0700 |
|---|---|---|
| committer | Mathieu Chartier <mathieuc@google.com> | 2013-09-17 10:03:00 -0700 |
| commit | c4621985bdfc2b27494087e5dee65a6d0cc5a632 (patch) | |
| tree | d8165f5b8d337e73942ee29d66fb40585dc7caf1 /runtime/gc/accounting | |
| parent | 5666afd6854b5634ae741dc8a3a633fc47d52168 (diff) | |
| download | art-c4621985bdfc2b27494087e5dee65a6d0cc5a632.zip art-c4621985bdfc2b27494087e5dee65a6d0cc5a632.tar.gz art-c4621985bdfc2b27494087e5dee65a6d0cc5a632.tar.bz2 | |
Fix race in root marking.
There was a race which caused the class linker / intern table to not
become dirty after adding a root. We now guard the is dirty flag by
the corresponding locks to prevent this from occuring. This was
causing roots to be occasionally missed.
Also fixes the bug where we occasionally scan more cards than
needed.
Bug: 10626133
Change-Id: I0f6e72d92035ff463954d66988ef610ea0df61be
Diffstat (limited to 'runtime/gc/accounting')
| -rw-r--r-- | runtime/gc/accounting/card_table-inl.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/runtime/gc/accounting/card_table-inl.h b/runtime/gc/accounting/card_table-inl.h index c5e8812..0cfbd6f 100644 --- a/runtime/gc/accounting/card_table-inl.h +++ b/runtime/gc/accounting/card_table-inl.h @@ -64,10 +64,9 @@ inline void CardTable::Scan(SpaceBitmap* bitmap, byte* scan_begin, byte* scan_en byte* aligned_end = card_end - (reinterpret_cast<uintptr_t>(card_end) & (sizeof(uintptr_t) - 1)); - // Now we have the words, we can send these to be processed in parallel. - uintptr_t* word_cur = reinterpret_cast<uintptr_t*>(card_cur); uintptr_t* word_end = reinterpret_cast<uintptr_t*>(aligned_end); - for (;;) { + for (uintptr_t* word_cur = reinterpret_cast<uintptr_t*>(card_cur); word_cur < word_end; + ++word_cur) { while (LIKELY(*word_cur == 0)) { ++word_cur; if (UNLIKELY(word_cur >= word_end)) { @@ -78,6 +77,8 @@ inline void CardTable::Scan(SpaceBitmap* bitmap, byte* scan_begin, byte* scan_en // Find the first dirty card. uintptr_t start_word = *word_cur; uintptr_t start = reinterpret_cast<uintptr_t>(AddrFromCard(reinterpret_cast<byte*>(word_cur))); + // TODO: Investigate if processing continuous runs of dirty cards with a single bitmap visit is + // more efficient. for (size_t i = 0; i < sizeof(uintptr_t); ++i) { if (static_cast<byte>(start_word) >= minimum_age) { auto* card = reinterpret_cast<byte*>(word_cur) + i; @@ -88,7 +89,6 @@ inline void CardTable::Scan(SpaceBitmap* bitmap, byte* scan_begin, byte* scan_en start_word >>= 8; start += kCardSize; } - ++word_cur; } exit_for: |