8310042: [Lilliput/JDK17] ZGC fixes and cleanups

Reviewed-by: shade
openjdk · Jun 14, 2023 · 9d6bbff · 9d6bbff
1 parent b3f0409
commit 9d6bbff
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Showing 2 changed files with 6 additions and 2 deletions.
diff --git a/src/hotspot/share/gc/z/c2/zBarrierSetC2.cpp b/src/hotspot/share/gc/z/c2/zBarrierSetC2.cpp
@@ -296,7 +296,7 @@ void ZBarrierSetC2::clone_at_expansion(PhaseMacroExpand* phase, ArrayCopyNode* a
       assert(src_offset == dest_offset, "should be equal");
       jlong offset = src_offset->get_long();
       if (offset != arrayOopDesc::base_offset_in_bytes(T_OBJECT)) {
-        assert(!UseCompressedClassPointers, "should only happen without compressed class pointers");
+        assert(!UseCompressedClassPointers || UseCompactObjectHeaders, "should only happen without compressed class pointers or with compact object headers");
         assert((arrayOopDesc::base_offset_in_bytes(T_OBJECT) - offset) == BytesPerLong, "unexpected offset");
         length = phase->transform_later(new SubLNode(length, phase->longcon(1))); // Size is in longs
         src_offset = phase->longcon(arrayOopDesc::base_offset_in_bytes(T_OBJECT));

diff --git a/src/hotspot/share/gc/z/zLiveMap.inline.hpp b/src/hotspot/share/gc/z/zLiveMap.inline.hpp
@@ -144,11 +144,15 @@ inline void ZLiveMap::iterate_segment(ObjectClosure* cl, BitMap::idx_t segment,
     // Calculate object address
     const uintptr_t addr = page_start + ((index / 2) << page_object_alignment_shift);
 
+    // Get the size of the object before calling the closure, which
+    // might overwrite the object in case we are relocating in-place.
+    const size_t size = ZUtils::object_size(addr);
+
     // Apply closure
     cl->do_object(ZOop::from_address(addr));
 
     // Find next bit after this object
-    const uintptr_t next_addr = align_up(addr + 1, 1 << page_object_alignment_shift);
+    const uintptr_t next_addr = align_up(addr + size, 1 << page_object_alignment_shift);
     const BitMap::idx_t next_index = ((next_addr - page_start) >> page_object_alignment_shift) * 2;
     if (next_index >= end_index) {
       // End of live map