Implement Unsafe.compareAndSwapInt

fernandezseb · Mar 5, 2024 · e17a0ca · e17a0ca
1 parent e81e20f
commit e17a0ca
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Showing 2 changed files with 26 additions and 0 deletions.
diff --git a/src/Library/sun/misc/Unsafe.cpp b/src/Library/sun/misc/Unsafe.cpp
@@ -25,6 +25,7 @@ JCALL void lib_sun_misc_Unsafe_registerNatives(NATIVE_ARGS)
     registerNative("sun/misc/Unsafe/addressSize", "()I", lib_sun_misc_Unsafe_addressSize);
     registerNative("sun/misc/Unsafe/objectFieldOffset", "(Ljava/lang/reflect/Field;)J", lib_sun_misc_Unsafe_objectFieldOffset);
     registerNative("sun/misc/Unsafe/compareAndSwapObject", "(Ljava/lang/Object;JLjava/lang/Object;Ljava/lang/Object;)Z", lib_sun_misc_Unsafe_compareAndSwapObject);
+    registerNative("sun/misc/Unsafe/compareAndSwapInt", "(Ljava/lang/Object;JII)Z", lib_sun_misc_Unsafe_compareAndSwapInt);
     registerNative("sun/misc/Unsafe/getIntVolatile", "(Ljava/lang/Object;J)I", lib_sun_misc_Unsafe_getIntVolatile);
 }
 
@@ -103,6 +104,30 @@ JCALL void lib_sun_misc_Unsafe_compareAndSwapObject(NATIVE_ARGS)
     }
 }
 
+JCALL void lib_sun_misc_Unsafe_compareAndSwapInt(NATIVE_ARGS)
+{
+    const Variable oObjectRef = thread->m_currentFrame->localVariables[1];
+    const Object* oObject = heap->getObject(oObjectRef.data);
+    const u8 offsetVar = ((static_cast<u8>(thread->m_currentFrame->localVariables[2].data) << 32) | static_cast<u8>(thread->m_currentFrame->localVariables[3].data));
+    const Variable expectedIntVar = thread->m_currentFrame->localVariables[4];
+    const Variable xIntVar = thread->m_currentFrame->localVariables[5];
+    constexpr u4 baseOffset = offsetof(Object, fields);
+    const u4 fieldIndex = (offsetVar-baseOffset)/sizeof(FieldData);
+    if (fieldIndex >= oObject->fields.size())
+    {
+        thread->internalError("Too big offset");
+    }
+    const FieldData* fieldData = &oObject->fields[fieldIndex];
+    if (fieldData->data->data == expectedIntVar.data)
+    {
+        fieldData->data->data = xIntVar.data;
+        thread->returnVar(Variable{VariableType_INT, 1u});
+    } else
+    {
+        thread->returnVar(Variable{VariableType_INT, 0u});
+    }
+}
+
 JCALL void lib_sun_misc_Unsafe_getIntVolatile(NATIVE_ARGS)
 {
     constexpr u4 baseOffset = offsetof(Object, fields);

diff --git a/src/Library/sun/misc/Unsafe.h b/src/Library/sun/misc/Unsafe.h
@@ -8,4 +8,5 @@ JCALL void lib_sun_misc_Unsafe_arrayIndexScale(NATIVE_ARGS);
 JCALL void lib_sun_misc_Unsafe_addressSize(NATIVE_ARGS);
 JCALL void lib_sun_misc_Unsafe_objectFieldOffset(NATIVE_ARGS);
 JCALL void lib_sun_misc_Unsafe_compareAndSwapObject(NATIVE_ARGS);
+JCALL void lib_sun_misc_Unsafe_compareAndSwapInt(NATIVE_ARGS);
 JCALL void lib_sun_misc_Unsafe_getIntVolatile(NATIVE_ARGS);