Add transactions for string resolve
Fixes a bug where resolved strings can be left in the dex cache after
a transaction is rolled back even though the interned string was
removed.
Added test in transaction_test.
Bug: 31239436
Test: test-art-host
Change-Id: I42c67bcefeae8db134cde34c480261f52db4102e
diff --git a/runtime/mirror/dex_cache.h b/runtime/mirror/dex_cache.h
index caf00c2..7d4021f 100644
--- a/runtime/mirror/dex_cache.h
+++ b/runtime/mirror/dex_cache.h
@@ -56,12 +56,20 @@
// it's always non-null if the string id branch succeeds (except for the 0th string id).
// Set the initial state for the 0th entry to be {0,1} which is guaranteed to fail
// the lookup string id == stored id branch.
+ StringDexCachePair(String* string, uint32_t string_idx)
+ : string_pointer(string),
+ string_index(string_idx) {}
+ StringDexCachePair() = default;
+ StringDexCachePair(const StringDexCachePair&) = default;
+ StringDexCachePair& operator=(const StringDexCachePair&) = default;
+
static void Initialize(StringDexCacheType* strings) {
mirror::StringDexCachePair first_elem;
first_elem.string_pointer = GcRoot<String>(nullptr);
- first_elem.string_index = 1;
+ first_elem.string_index = InvalidStringIndexForSlot(0);
strings[0].store(first_elem, std::memory_order_relaxed);
}
+
static GcRoot<String> LookupString(StringDexCacheType* dex_cache,
uint32_t string_idx,
uint32_t cache_size) {
@@ -71,10 +79,15 @@
DCHECK(!index_string.string_pointer.IsNull());
return index_string.string_pointer;
}
+
+ static uint32_t InvalidStringIndexForSlot(uint32_t slot) {
+ // Since the cache size is a power of two, 0 will always map to slot 0.
+ // Use 1 for slot 0 and 0 for all other slots.
+ return (slot == 0) ? 1u : 0u;
+ }
};
using StringDexCacheType = std::atomic<StringDexCachePair>;
-
// C++ mirror of java.lang.DexCache.
class MANAGED DexCache FINAL : public Object {
public:
@@ -164,6 +177,10 @@
void SetResolvedString(uint32_t string_idx, mirror::String* resolved) ALWAYS_INLINE
REQUIRES_SHARED(Locks::mutator_lock_);
+ // Clear a string for a string_idx, used to undo string intern transactions to make sure
+ // the string isn't kept live.
+ void ClearString(uint32_t string_idx) REQUIRES_SHARED(Locks::mutator_lock_);
+
Class* GetResolvedType(uint32_t type_idx) REQUIRES_SHARED(Locks::mutator_lock_);
void SetResolvedType(uint32_t type_idx, Class* resolved) REQUIRES_SHARED(Locks::mutator_lock_);