Fix reflect ConstantPool bootstrapping issues

We currently perform explicit native registration for
jdk.internal.reflect.ConstantPool. This occurs after JCL init in VM
startup. It is possible that ConstantPool will be used in JCL init before
the natives are registered, this will result in signal 218 since we have
public JNI stubs as a catch all for these capabilities.

I propose the following:

Step 1) (this PR)
- introduce a registerNative call in ConstantPool.

Step 2)
- update the JCL code to use the registerNative() in the static initializer
of the class, thereby ensuring that the natives are registered before the
class is used.

Step 3)
- remove the explicit register native call

With these steps we dont need to do any build coordination between openj9
and the extension repos.

Signed-off-by: tajila <atobia@ca.ibm.com>

runtime/jcl/common/sun_reflect_ConstantPool.c

@@ -292,7 +292,7 @@ getFieldAt(JNIEnv *env, jobject constantPoolOop, jint cpIndex, UDATA resolveFlag
 	if (NULL != constantPoolOop) {
 		J9RAMConstantRef *ramConstantRef = NULL;
 		jclass jlClass = NULL;
-		
+
 		vmFunctions->internalEnterVMFromJNI(vmThread);
 		resolveFlags |= (J9_RESOLVE_FLAG_NO_THROW_ON_FAIL | J9_RESOLVE_FLAG_NO_CLASS_INIT | J9_RESOLVE_FLAG_NO_CP_UPDATE);
 retry:
@@ -526,7 +526,7 @@ Java_sun_reflect_ConstantPool_getMemberRefInfoAt0(JNIEnv *env, jobject unusedObj
 	jobject nameObject = NULL;
 	jobject signatureObject = NULL;
 	J9VMThread *vmThread = (J9VMThread *) env;
-	J9InternalVMFunctions *vmFunctions = vmThread->javaVM->internalVMFunctions;	
+	J9InternalVMFunctions *vmFunctions = vmThread->javaVM->internalVMFunctions;
 	J9MemoryManagerFunctions *gcFunctions = vmThread->javaVM->memoryManagerFunctions;
 	SunReflectCPResult result = NULL_POINTER_EXCEPTION;
 
@@ -834,6 +834,12 @@ Java_jdk_internal_reflect_ConstantPool_getTagAt0(JNIEnv *env, jobject unusedObje
 	return 0;
 }
 
+void JNICALL
+Java_jdk_internal_reflect_ConstantPool_registerNatives(JNIEnv *env, jclass unused)
+{
+	registerJdkInternalReflectConstantPoolNatives(env);
+}
+
 /**
  * Registers natives for jdk.internal.reflect.ConstantPool.
  *
@@ -842,6 +848,8 @@ Java_jdk_internal_reflect_ConstantPool_getTagAt0(JNIEnv *env, jobject unusedObje
 jint
 registerJdkInternalReflectConstantPoolNatives(JNIEnv *env) {
 	jint result = 0;
+	J9JavaVM *vm = ((J9VMThread *)env)->javaVM;
+
 	JNINativeMethod natives[] = {
 		{
 			(char*)"getSize0",
@@ -919,6 +927,12 @@ registerJdkInternalReflectConstantPoolNatives(JNIEnv *env) {
 	/* jdk.internal.reflect.ConstantPool is currently cached in CLS_sun_reflect_ConstantPool */
 	jclass jdk_internal_reflect_ConstantPool = JCL_CACHE_GET(env, CLS_sun_reflect_ConstantPool);
 
+	/* This is temporary code, will be removed in the future. */
+	if (J9_ARE_ANY_BITS_SET(vm->extendedRuntimeFlags2, J9_EXTENDED_RUNTIME2_REFLECT_CONSTANTPOOL_REGISTER_NATIVES_CALLED)) {
+		goto _end;
+	}
+	vm->extendedRuntimeFlags2 |= J9_EXTENDED_RUNTIME2_REFLECT_CONSTANTPOOL_REGISTER_NATIVES_CALLED;
+
 	if (NULL == jdk_internal_reflect_ConstantPool) {
 		BOOLEAN rc = initializeSunReflectConstantPoolIDCache(env);
 

runtime/jcl/exports.cmake

@@ -591,6 +591,7 @@ if(NOT JAVA_SPEC_VERSION LESS 9)
 		Java_jdk_internal_reflect_ConstantPool_getNameAndTypeRefIndexAt0
 		Java_jdk_internal_reflect_ConstantPool_getNameAndTypeRefInfoAt0
 		Java_jdk_internal_reflect_ConstantPool_getTagAt0
+		Java_jdk_internal_reflect_ConstantPool_registerNatives
 	)
 endif()
 

runtime/jcl/uma/se9_exports.xml

@@ -1,19 +1,19 @@
-<!-- 
+<!--
 	Copyright IBM Corp. and others 2016
-	
+
 	This program and the accompanying materials are made available under
 	the terms of the Eclipse Public License 2.0 which accompanies this
 	distribution and is available at https://www.eclipse.org/legal/epl-2.0/
 	or the Apache License, Version 2.0 which accompanies this distribution and
 	is available at https://www.apache.org/licenses/LICENSE-2.0.
-	
+
 	This Source Code may also be made available under the following
 	Secondary Licenses when the conditions for such availability set
 	forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
 	General Public License, version 2 with the GNU Classpath
 	Exception [1] and GNU General Public License, version 2 with the
 	OpenJDK Assembly Exception [2].
-	
+
 	[1] https://www.gnu.org/software/classpath/license.html
 	[2] https://openjdk.org/legal/assembly-exception.html
 
@@ -62,6 +62,7 @@
 	<export name="Java_jdk_internal_reflect_ConstantPool_getNameAndTypeRefIndexAt0" />
 	<export name="Java_jdk_internal_reflect_ConstantPool_getNameAndTypeRefInfoAt0" />
 	<export name="Java_jdk_internal_reflect_ConstantPool_getTagAt0" />
+	<export name="Java_jdk_internal_reflect_ConstantPool_registerNatives" />
 	<export name="Java_java_lang_StackWalker_walkWrapperImpl" />
 	<export name="Java_java_lang_StackWalker_getImpl" />
 	<export name="Java_java_lang_invoke_MethodHandles_findNativeAddress">

runtime/oti/j9consts.h

@@ -362,6 +362,7 @@ extern "C" {
 #define J9_EXTENDED_RUNTIME2_USE_CONTAINER_SUPPORT 0x200000
 #define J9_EXTENDED_RUNTIME2_SHOW_CARRIER_FRAMES 0x400000
 #define J9_EXTENDED_RUNTIME2_CRIU_SINGLE_THROW_BLOCKING_EXCEPTIONS 0x800000
+#define J9_EXTENDED_RUNTIME2_REFLECT_CONSTANTPOOL_REGISTER_NATIVES_CALLED 0x1000000
 
 #define J9_OBJECT_HEADER_AGE_DEFAULT 0xA /* OBJECT_HEADER_AGE_DEFAULT */
 #define J9_OBJECT_HEADER_SHAPE_MASK 0xE /* OBJECT_HEADER_SHAPE_MASK */

runtime/oti/jclprots.h

@@ -1092,6 +1092,7 @@ jint JNICALL Java_jdk_internal_reflect_ConstantPool_getClassRefIndexAt0(JNIEnv *
 jint JNICALL Java_jdk_internal_reflect_ConstantPool_getNameAndTypeRefIndexAt0(JNIEnv *env, jobject unusedObject, jobject constantPoolOop, jint cpIndex);
 jobject JNICALL Java_jdk_internal_reflect_ConstantPool_getNameAndTypeRefInfoAt0(JNIEnv *env, jobject unusedObject, jobject constantPoolOop, jint cpIndex);
 jbyte JNICALL Java_jdk_internal_reflect_ConstantPool_getTagAt0(JNIEnv *env, jobject unusedObject, jobject constantPoolOop, jint cpIndex);
+void JNICALL Java_jdk_internal_reflect_ConstantPool_registerNatives(JNIEnv *env, jclass unused);
 jint registerJdkInternalReflectConstantPoolNatives(JNIEnv *env);
 
 /* java_lang_Access.c */