Merge pull request #13924 from ehrenjulzert/master

Add isFlattened and IsFlattenedArray Unsafe methods
eclipse-openj9 · Nov 21, 2021 · 1e7404f · 1e7404f
2 parents c4da870 + e295c84
commit 1e7404f
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Showing 5 changed files with 65 additions and 10 deletions.
diff --git a/jcl/src/java.base/share/classes/jdk/internal/misc/Unsafe.java b/jcl/src/java.base/share/classes/jdk/internal/misc/Unsafe.java
@@ -6555,8 +6555,23 @@ private static char convEndian(boolean isBigEndian, char value) {
 	public native <V> void putValue(Object obj, long offset, Class<?> clz, V value);
 	public native <V> V uninitializedDefaultValue(Class<?> clz);
 	public native <V> long valueHeaderSize(Class<V> clz);
+
+	/**
+	 * Determines whether a class is a flattened array
+	 *
+	 * @param clz the class to check
+	 * @return boolean value indicating whether the class is a flattened array
+	 */
 	public native boolean isFlattenedArray(Class<?> clz);
 
+	/**
+	 * Determines whether a field is flattened
+	 *
+	 * @param field the field to check
+	 * @return boolean value indicating whether the field is flattened
+	 */
+	public native boolean isFlattened(Field field);
+
 	public final <V> boolean compareAndSetValue(Object obj, long offset, Class<?> clz, V v1, V v2) {
 		throw OpenJDKCompileStubThrowError();
 	}
@@ -6625,11 +6640,6 @@ public final <V> Object getAndSetValueAcquire(Object obj, long offset, Class<?>
 		throw OpenJDKCompileStubThrowError();
 	}
 
-	public boolean isFlattened(java.lang.reflect.Field field) {
-		// ToDo: this is a temporary implementation - https://github.com/eclipse-openj9/openj9/issues/13614
-		return false;
-	}
-
 	public long getObjectSize(Object o) {
 		throw OpenJDKCompileStubThrowError();
 	}

diff --git a/runtime/oti/VMHelpers.hpp b/runtime/oti/VMHelpers.hpp
@@ -155,6 +155,7 @@ typedef enum {
 	J9_BCLOOP_SEND_TARGET_INL_UNSAFE_UNINITIALIZEDDEFAULTVALUE,
 	J9_BCLOOP_SEND_TARGET_INL_UNSAFE_VALUEHEADERSIZE,
 	J9_BCLOOP_SEND_TARGET_INL_UNSAFE_ISFLATTENEDARRAY,
+	J9_BCLOOP_SEND_TARGET_INL_UNSAFE_ISFLATTENED,
 #endif /* J9VM_OPT_VALHALLA_VALUE_TYPES */
 	J9_BCLOOP_SEND_TARGET_INL_INTERNALS_GET_INTERFACES,
 	J9_BCLOOP_SEND_TARGET_INL_ARRAY_NEW_ARRAY_IMPL,

diff --git a/runtime/vm/BytecodeInterpreter.hpp b/runtime/vm/BytecodeInterpreter.hpp
@@ -4021,15 +4021,52 @@ class INTERPRETER_CLASS
 		return EXECUTE_BYTECODE;
 	}
 
-	/* ToDo: unimplemented - https://github.com/eclipse-openj9/openj9/issues/13614 */
 	/* jdk.internal.misc.Unsafe: public native boolean isFlattenedArray(Class<?> clz); */
 	VMINLINE VM_BytecodeAction
 	inlUnsafeIsFlattenedArray(REGISTER_ARGS_LIST)
 	{
+		j9object_t cls = *(j9object_t*)_sp;
+
 		updateVMStruct(REGISTER_ARGS);
-		Assert_VM_unreachable();
+		buildInternalNativeStackFrame(REGISTER_ARGS);
+
+		I_32 result = (I_32)FALSE;
+		if (NULL != cls) {
+			J9Class *fieldClazz = J9VM_J9CLASS_FROM_HEAPCLASS(_currentThread, cls);
+			if (J9CLASS_IS_ARRAY(fieldClazz)) {
+				result = (I_32)J9_IS_J9CLASS_FLATTENED(fieldClazz);
+			}
+		}
+
+		restoreInternalNativeStackFrame(REGISTER_ARGS);
+		returnSingleFromINL(REGISTER_ARGS, result, 2);
 		return EXECUTE_BYTECODE;
 	}
+
+	VMINLINE VM_BytecodeAction
+	inlUnsafeIsFlattened(REGISTER_ARGS_LIST)
+	{
+		j9object_t field = *(j9object_t*)_sp;
+		VM_BytecodeAction rc = EXECUTE_BYTECODE;
+
+		updateVMStruct(REGISTER_ARGS);
+		buildInternalNativeStackFrame(REGISTER_ARGS);
+
+		if (NULL == field) {
+			rc = THROW_NPE;
+		} else {
+			J9JNIFieldID *fieldID = _vm->reflectFunctions.idFromFieldObject(_currentThread, NULL, field);
+			if (VM_VMHelpers::exceptionPending(_currentThread)) {
+				rc = GOTO_THROW_CURRENT_EXCEPTION;
+			} else {
+				I_32 result = (I_32)isFlattenableFieldFlattened(fieldID->declaringClass, fieldID->field);
+				restoreInternalNativeStackFrame(REGISTER_ARGS);
+				returnSingleFromINL(REGISTER_ARGS, result, 2);
+			}
+		}
+
+		return rc;
+	}
 #endif /* J9VM_OPT_VALHALLA_VALUE_TYPES */
 
 	/* java.lang.J9VMInternals: private native static void prepareClassImpl(Class clazz); */
@@ -9652,6 +9689,7 @@ class INTERPRETER_CLASS
 		JUMP_TABLE_ENTRY(J9_BCLOOP_SEND_TARGET_INL_UNSAFE_UNINITIALIZEDDEFAULTVALUE),
 		JUMP_TABLE_ENTRY(J9_BCLOOP_SEND_TARGET_INL_UNSAFE_VALUEHEADERSIZE),
 		JUMP_TABLE_ENTRY(J9_BCLOOP_SEND_TARGET_INL_UNSAFE_ISFLATTENEDARRAY),
+		JUMP_TABLE_ENTRY(J9_BCLOOP_SEND_TARGET_INL_UNSAFE_ISFLATTENED),
 #endif /* J9VM_OPT_VALHALLA_VALUE_TYPES */
 		JUMP_TABLE_ENTRY(J9_BCLOOP_SEND_TARGET_INL_INTERNALS_GET_INTERFACES),
 		JUMP_TABLE_ENTRY(J9_BCLOOP_SEND_TARGET_INL_ARRAY_NEW_ARRAY_IMPL),
@@ -10221,6 +10259,8 @@ runMethod: {
 		PERFORM_ACTION(inlUnsafeValueHeaderSize(REGISTER_ARGS));
 	JUMP_TARGET(J9_BCLOOP_SEND_TARGET_INL_UNSAFE_ISFLATTENEDARRAY):
 		PERFORM_ACTION(inlUnsafeIsFlattenedArray(REGISTER_ARGS));
+	JUMP_TARGET(J9_BCLOOP_SEND_TARGET_INL_UNSAFE_ISFLATTENED):
+		PERFORM_ACTION(inlUnsafeIsFlattened(REGISTER_ARGS));
 #endif /* J9VM_OPT_VALHALLA_VALUE_TYPES */
 	JUMP_TARGET(J9_BCLOOP_SEND_TARGET_INL_INTERNALS_GET_INTERFACES):
 		PERFORM_ACTION(inlInternalsGetInterfaces(REGISTER_ARGS));

diff --git a/runtime/vm/ValueTypeHelpers.cpp b/runtime/vm/ValueTypeHelpers.cpp
@@ -175,9 +175,12 @@ getFlattenableFieldOffset(J9Class *fieldOwner, J9ROMFieldShape *field)
 BOOLEAN
 isFlattenableFieldFlattened(J9Class *fieldOwner, J9ROMFieldShape *field)
 {
-        Assert_VM_notNull(fieldOwner);
-        Assert_VM_notNull(field);
-        BOOLEAN fieldFlattened = J9_IS_FIELD_FLATTENED(getFlattenableFieldType(fieldOwner, field), field);
+        BOOLEAN fieldFlattened = FALSE;
+        if (NULL != fieldOwner->flattenedClassCache) {
+                Assert_VM_notNull(fieldOwner);
+                Assert_VM_notNull(field);
+                fieldFlattened = J9_IS_FIELD_FLATTENED(getFlattenableFieldType(fieldOwner, field), field);
+        }
 
         return fieldFlattened;
 }

diff --git a/runtime/vm/bindnatv.cpp b/runtime/vm/bindnatv.cpp
@@ -282,6 +282,7 @@ static inlMapping mappings[] = {
 	{ "Java_jdk_internal_misc_Unsafe_uninitializedDefaultValue__Ljava_lang_Class_2", J9_BCLOOP_SEND_TARGET_INL_UNSAFE_UNINITIALIZEDDEFAULTVALUE },
 	{ "Java_jdk_internal_misc_Unsafe_valueHeaderSize__Ljava_lang_Class_2", J9_BCLOOP_SEND_TARGET_INL_UNSAFE_VALUEHEADERSIZE },
 	{ "Java_jdk_internal_misc_Unsafe_isFlattenedArray__Ljava_lang_Class_2", J9_BCLOOP_SEND_TARGET_INL_UNSAFE_ISFLATTENEDARRAY },
+	{ "Java_jdk_internal_misc_Unsafe_isFlattened__Ljava_lang_reflect_Field_2", J9_BCLOOP_SEND_TARGET_INL_UNSAFE_ISFLATTENED },
 #endif /* J9VM_OPT_VALHALLA_VALUE_TYPES */
 	{ "Java_java_lang_Thread_onSpinWait__", J9_BCLOOP_SEND_TARGET_INL_THREAD_ON_SPIN_WAIT },
 #if JAVA_SPEC_VERSION >= 11