Merge "Make CAS operations in Object use art::Atomic."

6 files changed, 45 insertions, 35 deletions

diff --git a/runtime/interpreter/interpreter.cc b/runtime/interpreter/interpreter.cc
index cb4d444..729444e 100644
--- a/runtime/interpreter/interpreter.cc
+++ b/runtime/interpreter/interpreter.cc
@@ -95,9 +95,11 @@ static void UnstartedRuntimeJni(Thread* self, ArtMethod* method,
     jint newValue = args[4];
     bool success;
     if (Runtime::Current()->IsActiveTransaction()) {
-      success = obj->CasField32<true>(MemberOffset(offset), expectedValue, newValue);
+      success = obj->CasFieldWeakSequentiallyConsistent32<true>(MemberOffset(offset),
+                                                                expectedValue, newValue);
     } else {
-      success = obj->CasField32<false>(MemberOffset(offset), expectedValue, newValue);
+      success = obj->CasFieldWeakSequentiallyConsistent32<false>(MemberOffset(offset),
+                                                                 expectedValue, newValue);
     }
     result->SetZ(success ? JNI_TRUE : JNI_FALSE);
   } else if (name == "void sun.misc.Unsafe.putObject(java.lang.Object, long, java.lang.Object)") {
diff --git a/runtime/mirror/object-inl.h b/runtime/mirror/object-inl.h
index 62c1162..089ef57 100644
--- a/runtime/mirror/object-inl.h
+++ b/runtime/mirror/object-inl.h
@@ -69,10 +69,10 @@ inline void Object::SetLockWord(LockWord new_val, bool as_volatile) {
   }
 }
 
-inline bool Object::CasLockWord(LockWord old_val, LockWord new_val) {
+inline bool Object::CasLockWordWeakSequentiallyConsistent(LockWord old_val, LockWord new_val) {
   // Force use of non-transactional mode and do not check.
-  return CasField32<false, false>(OFFSET_OF_OBJECT_MEMBER(Object, monitor_), old_val.GetValue(),
-                                  new_val.GetValue());
+  return CasFieldWeakSequentiallyConsistent32<false, false>(
+      OFFSET_OF_OBJECT_MEMBER(Object, monitor_), old_val.GetValue(), new_val.GetValue());
 }
 
 inline uint32_t Object::GetLockOwnerThreadId() {
@@ -131,21 +131,17 @@ inline bool Object::AtomicSetReadBarrierPointer(Object* expected_rb_ptr, Object*
   DCHECK(kUseBakerOrBrooksReadBarrier);
   MemberOffset offset = OFFSET_OF_OBJECT_MEMBER(Object, x_rb_ptr_);
   byte* raw_addr = reinterpret_cast<byte*>(this) + offset.SizeValue();
-  HeapReference<Object>* ref = reinterpret_cast<HeapReference<Object>*>(raw_addr);
+  Atomic<uint32_t>* atomic_rb_ptr = reinterpret_cast<Atomic<uint32_t>*>(raw_addr);
   HeapReference<Object> expected_ref(HeapReference<Object>::FromMirrorPtr(expected_rb_ptr));
   HeapReference<Object> new_ref(HeapReference<Object>::FromMirrorPtr(rb_ptr));
-  uint32_t expected_val = expected_ref.reference_;
-  uint32_t new_val;
   do {
-    uint32_t old_val = ref->reference_;
-    if (old_val != expected_val) {
+    if (UNLIKELY(atomic_rb_ptr->LoadRelaxed() != expected_ref.reference_)) {
       // Lost the race.
       return false;
     }
-    new_val = new_ref.reference_;
-  } while (!__sync_bool_compare_and_swap(
-      reinterpret_cast<uint32_t*>(raw_addr), expected_val, new_val));
-  DCHECK_EQ(new_val, ref->reference_);
+  } while (!atomic_rb_ptr->CompareExchangeWeakSequentiallyConsistent(expected_ref.reference_,
+                                                                     new_ref.reference_));
+  DCHECK_EQ(new_ref.reference_, atomic_rb_ptr->LoadRelaxed());
   return true;
 #else
   LOG(FATAL) << "Unreachable";
@@ -448,7 +444,8 @@ inline void Object::SetField32Volatile(MemberOffset field_offset, int32_t new_va
 }
 
 template<bool kTransactionActive, bool kCheckTransaction, VerifyObjectFlags kVerifyFlags>
-inline bool Object::CasField32(MemberOffset field_offset, int32_t old_value, int32_t new_value) {
+inline bool Object::CasFieldWeakSequentiallyConsistent32(MemberOffset field_offset,
+                                                         int32_t old_value, int32_t new_value) {
   if (kCheckTransaction) {
     DCHECK_EQ(kTransactionActive, Runtime::Current()->IsActiveTransaction());
   }
@@ -459,9 +456,9 @@ inline bool Object::CasField32(MemberOffset field_offset, int32_t old_value, int
     VerifyObject(this);
   }
   byte* raw_addr = reinterpret_cast<byte*>(this) + field_offset.Int32Value();
-  volatile int32_t* addr = reinterpret_cast<volatile int32_t*>(raw_addr);
+  AtomicInteger* atomic_addr = reinterpret_cast<AtomicInteger*>(raw_addr);
 
-  return __sync_bool_compare_and_swap(addr, old_value, new_value);
+  return atomic_addr->CompareExchangeWeakSequentiallyConsistent(old_value, new_value);
 }
 
 template<VerifyObjectFlags kVerifyFlags, bool kIsVolatile>
@@ -513,7 +510,8 @@ inline void Object::SetField64Volatile(MemberOffset field_offset, int64_t new_va
 }
 
 template<bool kTransactionActive, bool kCheckTransaction, VerifyObjectFlags kVerifyFlags>
-inline bool Object::CasField64(MemberOffset field_offset, int64_t old_value, int64_t new_value) {
+inline bool Object::CasFieldWeakSequentiallyConsistent64(MemberOffset field_offset,
+                                                         int64_t old_value, int64_t new_value) {
   if (kCheckTransaction) {
     DCHECK_EQ(kTransactionActive, Runtime::Current()->IsActiveTransaction());
   }
@@ -524,8 +522,8 @@ inline bool Object::CasField64(MemberOffset field_offset, int64_t old_value, int
     VerifyObject(this);
   }
   byte* raw_addr = reinterpret_cast<byte*>(this) + field_offset.Int32Value();
-  volatile int64_t* addr = reinterpret_cast<volatile int64_t*>(raw_addr);
-  return QuasiAtomic::Cas64(old_value, new_value, addr);
+  Atomic<int64_t>* atomic_addr = reinterpret_cast<Atomic<int64_t>*>(raw_addr);
+  return atomic_addr->CompareExchangeWeakSequentiallyConsistent(old_value, new_value);
 }
 
 template<class T, VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption,
@@ -615,8 +613,8 @@ inline HeapReference<Object>* Object::GetFieldObjectReferenceAddr(MemberOffset f
 }
 
 template<bool kTransactionActive, bool kCheckTransaction, VerifyObjectFlags kVerifyFlags>
-inline bool Object::CasFieldObject(MemberOffset field_offset, Object* old_value,
-                                   Object* new_value) {
+inline bool Object::CasFieldWeakSequentiallyConsistentObject(MemberOffset field_offset,
+                                                             Object* old_value, Object* new_value) {
   if (kCheckTransaction) {
     DCHECK_EQ(kTransactionActive, Runtime::Current()->IsActiveTransaction());
   }
@@ -632,11 +630,14 @@ inline bool Object::CasFieldObject(MemberOffset field_offset, Object* old_value,
   if (kTransactionActive) {
     Runtime::Current()->RecordWriteFieldReference(this, field_offset, old_value, true);
   }
-  byte* raw_addr = reinterpret_cast<byte*>(this) + field_offset.Int32Value();
-  volatile int32_t* addr = reinterpret_cast<volatile int32_t*>(raw_addr);
   HeapReference<Object> old_ref(HeapReference<Object>::FromMirrorPtr(old_value));
   HeapReference<Object> new_ref(HeapReference<Object>::FromMirrorPtr(new_value));
-  bool success =  __sync_bool_compare_and_swap(addr, old_ref.reference_, new_ref.reference_);
+  byte* raw_addr = reinterpret_cast<byte*>(this) + field_offset.Int32Value();
+  Atomic<uint32_t>* atomic_addr = reinterpret_cast<Atomic<uint32_t>*>(raw_addr);
+
+  bool success = atomic_addr->CompareExchangeWeakSequentiallyConsistent(old_ref.reference_,
+                                                                        new_ref.reference_);
+
   if (success) {
     Runtime::Current()->GetHeap()->WriteBarrierField(this, field_offset, new_value);
   }
diff --git a/runtime/mirror/object.cc b/runtime/mirror/object.cc
index 422a88b..e58091f 100644
--- a/runtime/mirror/object.cc
+++ b/runtime/mirror/object.cc
@@ -156,7 +156,7 @@ int32_t Object::IdentityHashCode() const {
         // loop iteration.
         LockWord hash_word(LockWord::FromHashCode(GenerateIdentityHashCode()));
         DCHECK_EQ(hash_word.GetState(), LockWord::kHashCode);
-        if (const_cast<Object*>(this)->CasLockWord(lw, hash_word)) {
+        if (const_cast<Object*>(this)->CasLockWordWeakSequentiallyConsistent(lw, hash_word)) {
           return hash_word.GetHashCode();
         }
         break;
diff --git a/runtime/mirror/object.h b/runtime/mirror/object.h
index c082443..d29011a 100644
--- a/runtime/mirror/object.h
+++ b/runtime/mirror/object.h
@@ -110,7 +110,8 @@ class MANAGED LOCKABLE Object {
   // have C++11 "strong" semantics.
   // TODO: In most, possibly all, cases, these assumptions are too strong.
   // Confirm and weaken the implementation.
-  bool CasLockWord(LockWord old_val, LockWord new_val) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  bool CasLockWordWeakSequentiallyConsistent(LockWord old_val, LockWord new_val)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
   uint32_t GetLockOwnerThreadId();
 
   mirror::Object* MonitorEnter(Thread* self) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
@@ -226,7 +227,8 @@ class MANAGED LOCKABLE Object {
 
   template<bool kTransactionActive, bool kCheckTransaction = true,
       VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags>
-  bool CasFieldObject(MemberOffset field_offset, Object* old_value, Object* new_value)
+  bool CasFieldWeakSequentiallyConsistentObject(MemberOffset field_offset, Object* old_value,
+                                                Object* new_value)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   template<VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags>
@@ -252,7 +254,8 @@ class MANAGED LOCKABLE Object {
 
   template<bool kTransactionActive, bool kCheckTransaction = true,
       VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags>
-  bool CasField32(MemberOffset field_offset, int32_t old_value, int32_t new_value) ALWAYS_INLINE
+  bool CasFieldWeakSequentiallyConsistent32(MemberOffset field_offset, int32_t old_value,
+                                            int32_t new_value) ALWAYS_INLINE
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   template<VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags, bool kIsVolatile = false>
@@ -275,7 +278,8 @@ class MANAGED LOCKABLE Object {
 
   template<bool kTransactionActive, bool kCheckTransaction = true,
       VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags>
-  bool CasField64(MemberOffset field_offset, int64_t old_value, int64_t new_value)
+  bool CasFieldWeakSequentiallyConsistent64(MemberOffset field_offset, int64_t old_value,
+                                            int64_t new_value)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   template<bool kTransactionActive, bool kCheckTransaction = true,
diff --git a/runtime/monitor.cc b/runtime/monitor.cc
index c3ec38d..5633a77 100644
--- a/runtime/monitor.cc
+++ b/runtime/monitor.cc
@@ -163,7 +163,7 @@ bool Monitor::Install(Thread* self) {
   }
   LockWord fat(this);
   // Publish the updated lock word, which may race with other threads.
-  bool success = GetObject()->CasLockWord(lw, fat);
+  bool success = GetObject()->CasLockWordWeakSequentiallyConsistent(lw, fat);
   // Lock profiling.
   if (success && owner_ != nullptr && lock_profiling_threshold_ != 0) {
     locking_method_ = owner_->GetCurrentMethod(&locking_dex_pc_);
@@ -722,7 +722,7 @@ mirror::Object* Monitor::MonitorEnter(Thread* self, mirror::Object* obj) {
     switch (lock_word.GetState()) {
       case LockWord::kUnlocked: {
         LockWord thin_locked(LockWord::FromThinLockId(thread_id, 0));
-        if (h_obj->CasLockWord(lock_word, thin_locked)) {
+        if (h_obj->CasLockWordWeakSequentiallyConsistent(lock_word, thin_locked)) {
           // CasLockWord enforces more than the acquire ordering we need here.
           return h_obj.Get();  // Success!
         }
diff --git a/runtime/native/sun_misc_Unsafe.cc b/runtime/native/sun_misc_Unsafe.cc
index d23cfff..7cc4cac 100644
--- a/runtime/native/sun_misc_Unsafe.cc
+++ b/runtime/native/sun_misc_Unsafe.cc
@@ -28,7 +28,8 @@ static jboolean Unsafe_compareAndSwapInt(JNIEnv* env, jobject, jobject javaObj,
   ScopedFastNativeObjectAccess soa(env);
   mirror::Object* obj = soa.Decode<mirror::Object*>(javaObj);
   // JNI must use non transactional mode.
-  bool success = obj->CasField32<false>(MemberOffset(offset), expectedValue, newValue);
+  bool success = obj->CasFieldWeakSequentiallyConsistent32<false>(MemberOffset(offset),
+                                                                  expectedValue, newValue);
   return success ? JNI_TRUE : JNI_FALSE;
 }
 
@@ -37,7 +38,8 @@ static jboolean Unsafe_compareAndSwapLong(JNIEnv* env, jobject, jobject javaObj,
   ScopedFastNativeObjectAccess soa(env);
   mirror::Object* obj = soa.Decode<mirror::Object*>(javaObj);
   // JNI must use non transactional mode.
-  bool success = obj->CasField64<false>(MemberOffset(offset), expectedValue, newValue);
+  bool success = obj->CasFieldWeakSequentiallyConsistent64<false>(MemberOffset(offset),
+                                                                  expectedValue, newValue);
   return success ? JNI_TRUE : JNI_FALSE;
 }
 
@@ -48,7 +50,8 @@ static jboolean Unsafe_compareAndSwapObject(JNIEnv* env, jobject, jobject javaOb
   mirror::Object* expectedValue = soa.Decode<mirror::Object*>(javaExpectedValue);
   mirror::Object* newValue = soa.Decode<mirror::Object*>(javaNewValue);
   // JNI must use non transactional mode.
-  bool success = obj->CasFieldObject<false>(MemberOffset(offset), expectedValue, newValue);
+  bool success = obj->CasFieldWeakSequentiallyConsistentObject<false>(MemberOffset(offset),
+                                                                      expectedValue, newValue);
   return success ? JNI_TRUE : JNI_FALSE;
 }