Refactor and cleanup DexCache.

- Introduce macros to avoid duplicating code for each dex cache kind.
- Remove preResolvedStrings, this was unused.
- Remove dex cache length fields, we can easily infer them.

Test: test.py
Change-Id: I1e0bc8cf078ce8e09c4d756c63be32cb344fcce1

1 files changed, 58 insertions, 161 deletions

diff --git a/runtime/mirror/dex_cache-inl.h b/runtime/mirror/dex_cache-inl.h
index 402bb72945..3cbfb40253 100644
--- a/runtime/mirror/dex_cache-inl.h
+++ b/runtime/mirror/dex_cache-inl.h
@@ -54,10 +54,7 @@ static void InitializeArray(GcRoot<T>*) {
 }
 
 template<typename T, size_t kMaxCacheSize>
-T* DexCache::AllocArray(MemberOffset obj_offset,
-                        MemberOffset num_offset,
-                        size_t num,
-                        LinearAllocKind kind) {
+T* DexCache::AllocArray(MemberOffset obj_offset, size_t num, LinearAllocKind kind) {
   num = std::min<size_t>(num, kMaxCacheSize);
   if (num == 0) {
     return nullptr;
@@ -79,7 +76,6 @@ T* DexCache::AllocArray(MemberOffset obj_offset,
   }
   array = reinterpret_cast<T*>(alloc->AllocAlign16(self, RoundUp(num * sizeof(T), 16), kind));
   InitializeArray(array);  // Ensure other threads see the array initialized.
-  dex_cache->SetField32Volatile<false, false>(num_offset, num);
   dex_cache->SetField64Volatile<false, false>(obj_offset, reinterpret_cast64<uint64_t>(array));
   return array;
 }
@@ -89,14 +85,6 @@ inline DexCachePair<T>::DexCachePair(ObjPtr<T> object, uint32_t index)
     : object(object), index(index) {}
 
 template <typename T>
-inline void DexCachePair<T>::Initialize(std::atomic<DexCachePair<T>>* dex_cache) {
-  DexCachePair<T> first_elem;
-  first_elem.object = GcRoot<T>(nullptr);
-  first_elem.index = InvalidIndexForSlot(0);
-  dex_cache[0].store(first_elem, std::memory_order_relaxed);
-}
-
-template <typename T>
 inline T* DexCachePair<T>::GetObjectForIndex(uint32_t idx) {
   if (idx != index) {
     return nullptr;
@@ -106,11 +94,22 @@ inline T* DexCachePair<T>::GetObjectForIndex(uint32_t idx) {
 }
 
 template <typename T>
+inline void DexCachePair<T>::Initialize(std::atomic<DexCachePair<T>>* dex_cache) {
+  DexCachePair<T> first_elem;
+  first_elem.object = GcRoot<T>(nullptr);
+  first_elem.index = InvalidIndexForSlot(0);
+  dex_cache[0].store(first_elem, std::memory_order_relaxed);
+}
+
+template <typename T>
 inline void NativeDexCachePair<T>::Initialize(std::atomic<NativeDexCachePair<T>>* dex_cache) {
   NativeDexCachePair<T> first_elem;
   first_elem.object = nullptr;
   first_elem.index = InvalidIndexForSlot(0);
-  DexCache::SetNativePair(dex_cache, 0, first_elem);
+
+  auto* array = reinterpret_cast<std::atomic<AtomicPair<uintptr_t>>*>(dex_cache);
+  AtomicPair<uintptr_t> v(reinterpret_cast<size_t>(first_elem.object), first_elem.index);
+  AtomicPairStoreRelease(&array[0], v);
 }
 
 inline uint32_t DexCache::ClassSize(PointerSize pointer_size) {
@@ -118,34 +117,21 @@ inline uint32_t DexCache::ClassSize(PointerSize pointer_size) {
   return Class::ComputeClassSize(true, vtable_entries, 0, 0, 0, 0, 0, pointer_size);
 }
 
-inline uint32_t DexCache::StringSlotIndex(dex::StringIndex string_idx) {
-  DCHECK_LT(string_idx.index_, GetDexFile()->NumStringIds());
-  const uint32_t slot_idx = string_idx.index_ % kDexCacheStringCacheSize;
-  DCHECK_LT(slot_idx, NumStrings());
-  return slot_idx;
-}
-
 inline String* DexCache::GetResolvedString(dex::StringIndex string_idx) {
-  StringDexCacheType* strings = GetStrings();
+  auto* strings = GetStrings();
   if (UNLIKELY(strings == nullptr)) {
     return nullptr;
   }
-  return strings[StringSlotIndex(string_idx)].load(
-      std::memory_order_relaxed).GetObjectForIndex(string_idx.index_);
+  return strings->Get(string_idx.index_);
 }
 
 inline void DexCache::SetResolvedString(dex::StringIndex string_idx, ObjPtr<String> resolved) {
   DCHECK(resolved != nullptr);
-  StringDexCacheType* strings = GetStrings();
+  auto* strings = GetStrings();
   if (UNLIKELY(strings == nullptr)) {
-    strings = AllocArray<StringDexCacheType, kDexCacheStringCacheSize>(
-        StringsOffset(),
-        NumStringsOffset(),
-        GetDexFile()->NumStringIds(),
-        LinearAllocKind::kDexCacheArray);
+    strings = AllocateStrings();
   }
-  strings[StringSlotIndex(string_idx)].store(
-      StringDexCachePair(resolved, string_idx.index_), std::memory_order_relaxed);
+  strings->Set(string_idx.index_, resolved.Ptr());
   Runtime* const runtime = Runtime::Current();
   if (UNLIKELY(runtime->IsActiveTransaction())) {
     DCHECK(runtime->IsAotCompiler());
@@ -157,102 +143,63 @@ inline void DexCache::SetResolvedString(dex::StringIndex string_idx, ObjPtr<Stri
 
 inline void DexCache::ClearString(dex::StringIndex string_idx) {
   DCHECK(Runtime::Current()->IsAotCompiler());
-  uint32_t slot_idx = StringSlotIndex(string_idx);
-  StringDexCacheType* strings = GetStrings();
+  auto* strings = GetStrings();
   if (UNLIKELY(strings == nullptr)) {
     return;
   }
-  StringDexCacheType* slot = &strings[slot_idx];
-  // This is racy but should only be called from the transactional interpreter.
-  if (slot->load(std::memory_order_relaxed).index == string_idx.index_) {
-    StringDexCachePair cleared(nullptr, StringDexCachePair::InvalidIndexForSlot(slot_idx));
-    slot->store(cleared, std::memory_order_relaxed);
-  }
-}
-
-inline uint32_t DexCache::TypeSlotIndex(dex::TypeIndex type_idx) {
-  DCHECK_LT(type_idx.index_, GetDexFile()->NumTypeIds());
-  const uint32_t slot_idx = type_idx.index_ % kDexCacheTypeCacheSize;
-  DCHECK_LT(slot_idx, NumResolvedTypes());
-  return slot_idx;
+  strings->Clear(string_idx.index_);
 }
 
 inline Class* DexCache::GetResolvedType(dex::TypeIndex type_idx) {
   // It is theorized that a load acquire is not required since obtaining the resolved class will
   // always have an address dependency or a lock.
-  TypeDexCacheType* resolved_types = GetResolvedTypes();
+  auto* resolved_types = GetResolvedTypes();
   if (UNLIKELY(resolved_types == nullptr)) {
     return nullptr;
   }
-  return resolved_types[TypeSlotIndex(type_idx)].load(
-      std::memory_order_relaxed).GetObjectForIndex(type_idx.index_);
+  return resolved_types->Get(type_idx.index_);
 }
 
 inline void DexCache::SetResolvedType(dex::TypeIndex type_idx, ObjPtr<Class> resolved) {
   DCHECK(resolved != nullptr);
   DCHECK(resolved->IsResolved()) << resolved->GetStatus();
-  TypeDexCacheType* resolved_types = GetResolvedTypes();
+  auto* resolved_types = GetResolvedTypes();
   if (UNLIKELY(resolved_types == nullptr)) {
-    resolved_types = AllocArray<TypeDexCacheType, kDexCacheTypeCacheSize>(
-        ResolvedTypesOffset(),
-        NumResolvedTypesOffset(),
-        GetDexFile()->NumTypeIds(),
-        LinearAllocKind::kDexCacheArray);
+    resolved_types = AllocateResolvedTypes();
   }
   // TODO default transaction support.
   // Use a release store for SetResolvedType. This is done to prevent other threads from seeing a
   // class but not necessarily seeing the loaded members like the static fields array.
   // See b/32075261.
-  resolved_types[TypeSlotIndex(type_idx)].store(
-      TypeDexCachePair(resolved, type_idx.index_), std::memory_order_release);
+  resolved_types->Set(type_idx.index_, resolved.Ptr());
   // TODO: Fine-grained marking, so that we don't need to go through all arrays in full.
   WriteBarrier::ForEveryFieldWrite(this);
 }
 
 inline void DexCache::ClearResolvedType(dex::TypeIndex type_idx) {
   DCHECK(Runtime::Current()->IsAotCompiler());
-  TypeDexCacheType* resolved_types = GetResolvedTypes();
+  auto* resolved_types = GetResolvedTypes();
   if (UNLIKELY(resolved_types == nullptr)) {
     return;
   }
-  uint32_t slot_idx = TypeSlotIndex(type_idx);
-  TypeDexCacheType* slot = &resolved_types[slot_idx];
-  // This is racy but should only be called from the single-threaded ImageWriter and tests.
-  if (slot->load(std::memory_order_relaxed).index == type_idx.index_) {
-    TypeDexCachePair cleared(nullptr, TypeDexCachePair::InvalidIndexForSlot(slot_idx));
-    slot->store(cleared, std::memory_order_relaxed);
-  }
-}
-
-inline uint32_t DexCache::MethodTypeSlotIndex(dex::ProtoIndex proto_idx) {
-  DCHECK(Runtime::Current()->IsMethodHandlesEnabled());
-  DCHECK_LT(proto_idx.index_, GetDexFile()->NumProtoIds());
-  const uint32_t slot_idx = proto_idx.index_ % kDexCacheMethodTypeCacheSize;
-  DCHECK_LT(slot_idx, NumResolvedMethodTypes());
-  return slot_idx;
+  resolved_types->Clear(type_idx.index_);
 }
 
 inline MethodType* DexCache::GetResolvedMethodType(dex::ProtoIndex proto_idx) {
-  MethodTypeDexCacheType* methods = GetResolvedMethodTypes();
+  auto* methods = GetResolvedMethodTypes();
   if (UNLIKELY(methods == nullptr)) {
     return nullptr;
   }
-  return methods[MethodTypeSlotIndex(proto_idx)].load(
-      std::memory_order_relaxed).GetObjectForIndex(proto_idx.index_);
+  return methods->Get(proto_idx.index_);
 }
 
 inline void DexCache::SetResolvedMethodType(dex::ProtoIndex proto_idx, MethodType* resolved) {
   DCHECK(resolved != nullptr);
-  MethodTypeDexCacheType* methods = GetResolvedMethodTypes();
+  auto* methods = GetResolvedMethodTypes();
   if (UNLIKELY(methods == nullptr)) {
-    methods = AllocArray<MethodTypeDexCacheType, kDexCacheMethodTypeCacheSize>(
-        ResolvedMethodTypesOffset(),
-        NumResolvedMethodTypesOffset(),
-        GetDexFile()->NumProtoIds(),
-        LinearAllocKind::kDexCacheArray);
+    methods = AllocateResolvedMethodTypes();
   }
-  methods[MethodTypeSlotIndex(proto_idx)].store(
-      MethodTypeDexCachePair(resolved, proto_idx.index_), std::memory_order_relaxed);
+  methods->Set(proto_idx.index_, resolved);
   Runtime* const runtime = Runtime::Current();
   if (UNLIKELY(runtime->IsActiveTransaction())) {
     DCHECK(runtime->IsAotCompiler());
@@ -264,14 +211,11 @@ inline void DexCache::SetResolvedMethodType(dex::ProtoIndex proto_idx, MethodTyp
 
 inline void DexCache::ClearMethodType(dex::ProtoIndex proto_idx) {
   DCHECK(Runtime::Current()->IsAotCompiler());
-  uint32_t slot_idx = MethodTypeSlotIndex(proto_idx);
-  MethodTypeDexCacheType* slot = &GetResolvedMethodTypes()[slot_idx];
-  // This is racy but should only be called from the transactional interpreter.
-  if (slot->load(std::memory_order_relaxed).index == proto_idx.index_) {
-    MethodTypeDexCachePair cleared(nullptr,
-                                   MethodTypeDexCachePair::InvalidIndexForSlot(proto_idx.index_));
-    slot->store(cleared, std::memory_order_relaxed);
+  auto* methods = GetResolvedMethodTypes();
+  if (methods == nullptr) {
+    return;
   }
+  methods->Clear(proto_idx.index_);
 }
 
 inline CallSite* DexCache::GetResolvedCallSite(uint32_t call_site_idx) {
@@ -296,11 +240,7 @@ inline ObjPtr<CallSite> DexCache::SetResolvedCallSite(uint32_t call_site_idx,
   GcRoot<mirror::CallSite> candidate(call_site);
   GcRoot<CallSite>* call_sites = GetResolvedCallSites();
   if (UNLIKELY(call_sites == nullptr)) {
-    call_sites = AllocArray<GcRoot<CallSite>, std::numeric_limits<size_t>::max()>(
-        ResolvedCallSitesOffset(),
-        NumResolvedCallSitesOffset(),
-        GetDexFile()->NumCallSiteIds(),
-        LinearAllocKind::kGCRootArray);
+    call_sites = AllocateResolvedCallSites();
   }
   GcRoot<mirror::CallSite>& target = call_sites[call_site_idx];
 
@@ -316,103 +256,60 @@ inline ObjPtr<CallSite> DexCache::SetResolvedCallSite(uint32_t call_site_idx,
   }
 }
 
-inline uint32_t DexCache::FieldSlotIndex(uint32_t field_idx) {
-  DCHECK_LT(field_idx, GetDexFile()->NumFieldIds());
-  const uint32_t slot_idx = field_idx % kDexCacheFieldCacheSize;
-  DCHECK_LT(slot_idx, NumResolvedFields());
-  return slot_idx;
-}
-
 inline ArtField* DexCache::GetResolvedField(uint32_t field_idx) {
-  FieldDexCacheType* fields = GetResolvedFields();
+  auto* fields = GetResolvedFields();
   if (UNLIKELY(fields == nullptr)) {
     return nullptr;
   }
-  auto pair = GetNativePair(fields, FieldSlotIndex(field_idx));
-  return pair.GetObjectForIndex(field_idx);
+  return fields->Get(field_idx);
 }
 
 inline void DexCache::SetResolvedField(uint32_t field_idx, ArtField* field) {
   DCHECK(field != nullptr);
-  FieldDexCachePair pair(field, field_idx);
-  FieldDexCacheType* fields = GetResolvedFields();
+  auto* fields = GetResolvedFields();
   if (UNLIKELY(fields == nullptr)) {
-    fields = AllocArray<FieldDexCacheType, kDexCacheFieldCacheSize>(
-        ResolvedFieldsOffset(),
-        NumResolvedFieldsOffset(),
-        GetDexFile()->NumFieldIds(),
-        LinearAllocKind::kNoGCRoots);
+    fields = AllocateResolvedFields();
   }
-  SetNativePair(fields, FieldSlotIndex(field_idx), pair);
-}
-
-inline uint32_t DexCache::MethodSlotIndex(uint32_t method_idx) {
-  DCHECK_LT(method_idx, GetDexFile()->NumMethodIds());
-  const uint32_t slot_idx = method_idx % kDexCacheMethodCacheSize;
-  DCHECK_LT(slot_idx, NumResolvedMethods());
-  return slot_idx;
+  fields->Set(field_idx, field);
 }
 
 inline ArtMethod* DexCache::GetResolvedMethod(uint32_t method_idx) {
-  MethodDexCacheType* methods = GetResolvedMethods();
+  auto* methods = GetResolvedMethods();
   if (UNLIKELY(methods == nullptr)) {
     return nullptr;
   }
-  auto pair = GetNativePair(methods, MethodSlotIndex(method_idx));
-  return pair.GetObjectForIndex(method_idx);
+  return methods->Get(method_idx);
 }
 
 inline void DexCache::SetResolvedMethod(uint32_t method_idx, ArtMethod* method) {
   DCHECK(method != nullptr);
-  MethodDexCachePair pair(method, method_idx);
-  MethodDexCacheType* methods = GetResolvedMethods();
+  auto* methods = GetResolvedMethods();
   if (UNLIKELY(methods == nullptr)) {
-    methods = AllocArray<MethodDexCacheType, kDexCacheMethodCacheSize>(
-        ResolvedMethodsOffset(),
-        NumResolvedMethodsOffset(),
-        GetDexFile()->NumMethodIds(),
-        LinearAllocKind::kNoGCRoots);
+    methods = AllocateResolvedMethods();
   }
-  SetNativePair(methods, MethodSlotIndex(method_idx), pair);
+  methods->Set(method_idx, method);
 }
 
-template <typename T>
-NativeDexCachePair<T> DexCache::GetNativePair(std::atomic<NativeDexCachePair<T>>* pair_array,
-                                              size_t idx) {
-  auto* array = reinterpret_cast<std::atomic<AtomicPair<uintptr_t>>*>(pair_array);
-  AtomicPair<uintptr_t> value = AtomicPairLoadAcquire(&array[idx]);
-  return NativeDexCachePair<T>(reinterpret_cast<T*>(value.first), value.second);
-}
-
-template <typename T>
-void DexCache::SetNativePair(std::atomic<NativeDexCachePair<T>>* pair_array,
-                             size_t idx,
-                             NativeDexCachePair<T> pair) {
-  auto* array = reinterpret_cast<std::atomic<AtomicPair<uintptr_t>>*>(pair_array);
-  AtomicPair<uintptr_t> v(reinterpret_cast<size_t>(pair.object), pair.index);
-  AtomicPairStoreRelease(&array[idx], v);
-}
-
-template <typename T,
-          ReadBarrierOption kReadBarrierOption,
-          typename Visitor>
-inline void VisitDexCachePairs(std::atomic<DexCachePair<T>>* pairs,
+template <ReadBarrierOption kReadBarrierOption,
+          typename Visitor,
+          typename T>
+inline void VisitDexCachePairs(T* array,
                                size_t num_pairs,
                                const Visitor& visitor)
     REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(Locks::heap_bitmap_lock_) {
   // Check both the data pointer and count since the array might be initialized
   // concurrently on other thread, and we might observe just one of the values.
-  for (size_t i = 0; pairs != nullptr && i < num_pairs; ++i) {
-    DexCachePair<T> source = pairs[i].load(std::memory_order_relaxed);
+  for (size_t i = 0; array != nullptr && i < num_pairs; ++i) {
+    auto source = array->GetPair(i);
     // NOTE: We need the "template" keyword here to avoid a compilation
     // failure. GcRoot<T> is a template argument-dependent type and we need to
     // tell the compiler to treat "Read" as a template rather than a field or
     // function. Otherwise, on encountering the "<" token, the compiler would
     // treat "Read" as a field.
-    T* const before = source.object.template Read<kReadBarrierOption>();
+    auto const before = source.object.template Read<kReadBarrierOption>();
     visitor.VisitRootIfNonNull(source.object.AddressWithoutBarrier());
     if (source.object.template Read<kReadBarrierOption>() != before) {
-      pairs[i].store(source, std::memory_order_relaxed);
+      array->SetPair(i, source);
     }
   }
 }
@@ -443,13 +340,13 @@ template <VerifyObjectFlags kVerifyFlags,
           ReadBarrierOption kReadBarrierOption,
           typename Visitor>
 inline void DexCache::VisitNativeRoots(const Visitor& visitor) {
-  VisitDexCachePairs<String, kReadBarrierOption, Visitor>(
+  VisitDexCachePairs<kReadBarrierOption, Visitor>(
       GetStrings<kVerifyFlags>(), NumStrings<kVerifyFlags>(), visitor);
 
-  VisitDexCachePairs<Class, kReadBarrierOption, Visitor>(
+  VisitDexCachePairs<kReadBarrierOption, Visitor>(
       GetResolvedTypes<kVerifyFlags>(), NumResolvedTypes<kVerifyFlags>(), visitor);
 
-  VisitDexCachePairs<MethodType, kReadBarrierOption, Visitor>(
+  VisitDexCachePairs<kReadBarrierOption, Visitor>(
       GetResolvedMethodTypes<kVerifyFlags>(), NumResolvedMethodTypes<kVerifyFlags>(), visitor);
 
   GcRoot<mirror::CallSite>* resolved_call_sites = GetResolvedCallSites<kVerifyFlags>();