Fix race with LOS Begin() and End()
There was a race for the first large object allocation that cause
callers of Begin() and End() to see a null End() and non-null
Begin(). The fix is to hold the lock and get both Begin() and End().
Bug: 32387879
Test: test-art-host CC
Change-Id: I6173bf3a55d3ba017ffa5b5e9f566025c65b7555
diff --git a/runtime/gc/collector/concurrent_copying.cc b/runtime/gc/collector/concurrent_copying.cc
index c43b048..8bb90e1 100644
--- a/runtime/gc/collector/concurrent_copying.cc
+++ b/runtime/gc/collector/concurrent_copying.cc
@@ -1518,8 +1518,9 @@
accounting::LargeObjectBitmap* const live_bitmap = los->GetLiveBitmap();
accounting::LargeObjectBitmap* const mark_bitmap = los->GetMarkBitmap();
// Walk through all of the objects and explicitly mark the zygote ones so they don't get swept.
- live_bitmap->VisitMarkedRange(reinterpret_cast<uintptr_t>(los->Begin()),
- reinterpret_cast<uintptr_t>(los->End()),
+ std::pair<uint8_t*, uint8_t*> range = los->GetBeginEndAtomic();
+ live_bitmap->VisitMarkedRange(reinterpret_cast<uintptr_t>(range.first),
+ reinterpret_cast<uintptr_t>(range.second),
[mark_bitmap, los, self](mirror::Object* obj)
REQUIRES(Locks::heap_bitmap_lock_)
REQUIRES_SHARED(Locks::mutator_lock_) {
diff --git a/runtime/gc/collector/semi_space.cc b/runtime/gc/collector/semi_space.cc
index 2cb1767..2ff4a3f 100644
--- a/runtime/gc/collector/semi_space.cc
+++ b/runtime/gc/collector/semi_space.cc
@@ -408,8 +408,9 @@
// classes (primitive array classes) that could move though they
// don't contain any other references.
accounting::LargeObjectBitmap* large_live_bitmap = los->GetLiveBitmap();
- large_live_bitmap->VisitMarkedRange(reinterpret_cast<uintptr_t>(los->Begin()),
- reinterpret_cast<uintptr_t>(los->End()),
+ std::pair<uint8_t*, uint8_t*> range = los->GetBeginEndAtomic();
+ large_live_bitmap->VisitMarkedRange(reinterpret_cast<uintptr_t>(range.first),
+ reinterpret_cast<uintptr_t>(range.second),
[this](mirror::Object* obj)
REQUIRES(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
ScanObject(obj);