Override TR_ResolvedJ9Method::isCompilable() for JITServer

[mpirvu]

TR_ResolvedJ9Method::isCompilable() accesses some fields from JavaVM and it's not safe to use as is in out-of-process compilations.
To fix this we have two alternatives:

1. When the server constructs a ResolvedJ9Method, a mirror resolved method is also built at the client. When that happens we can precompute the isCompilable information and store it into a boolean field which will be passed to the server. The disadvantage is that we have to precompute this field even though the optimizer may not ask about it.
2. For each client, store at the server the JavaVM fields that isCompilable is asking for.

Solution 2 should be preferred because it has less overhead. However, solution 2 is contingent on these JavaVM fields being populated exactly once before first compilation takes place:
javaVM->doPrivilegedWithContextMethodID1
javaVM->doPrivilegedWithContextMethodID2
javaVM->doPrivilegedWithContextPermissionMethodID1
javaVM->doPrivilegedWithContextPermissionMethodID2
javaVM->nativeLibrariesLoadMethodID

[mpirvu]

Rectification: the code reads

   J9JNIMethodID * magic = (J9JNIMethodID *) javaVM->doPrivilegedWithContextMethodID1;
   if (magic && ramMethod() == magic->method)

so it's not doPrivilegedWithContextMethodID1 that needs to be cached, but the ramMethod stored inside.

This field is set in boolean JNICALL Java_java_security_AccessController_initializeInternal(JNIEnv *env, jclass thisClz)

jboolean JNICALL Java_java_security_AccessController_initializeInternal(JNIEnv *env, jclass thisClz)
{
	J9JavaVM *javaVM = ((J9VMThread *) env)->javaVM;
	jclass accessControllerClass;
	jmethodID mid;

	accessControllerClass = (*env)->FindClass(env, "java/security/AccessController");
	if(accessControllerClass == NULL) goto fail;
      ...
	mid = (*env)->GetStaticMethodID(env, accessControllerClass, "doPrivileged", "(Ljava/security/PrivilegedAction;Ljava/security/AccessControlContext;)Ljava/lang/Object;");
	if(mid == NULL) goto fail;
	javaVM->doPrivilegedWithContextMethodID1 = (UDATA) mid;
     ...
}

I don't know if java/security/AccessController can ever be modified, but if it can be, we must reset the cached fields.

[mpirvu]

I see code that tests whether doPrivilegedWithContextMethodID1 is NULL. So, this field starts as NULL and when the Java program executes the JNI call java/security/AccessController.initializeInternal(), that field (and others) are populated.
Interestingly I found on the internet that java.security.AccessController is deprecated for removal since Java17

[mpirvu]

Another field that ResolveJ9Method looks at is javaVM->nativeLibrariesLoadMethodID;
This is set in standardInit(J9JavaVM *vm, char *dllName), but only for Java >= 15

if JAVA_SPEC_VERSION >= 15
				JNIEnv *env = (JNIEnv*)vmThread;
				jclass clz = (*env)->FindClass(env, "jdk/internal/loader/NativeLibraries");
				jmethodID mid = NULL;
				if (NULL == clz) {
					goto _fail;
				}
#if (17 <= JAVA_SPEC_VERSION) && (JAVA_SPEC_VERSION <= 18)
				mid = (*env)->GetStaticMethodID(env, clz, "load", "(Ljdk/internal/loader/NativeLibraries$NativeLibraryImpl;Ljava/lang/String;ZZZ)Z");
#else /* (17 <= JAVA_SPEC_VERSION) && (JAVA_SPEC_VERSION <= 18) */
				mid = (*env)->GetStaticMethodID(env, clz, "load", "(Ljdk/internal/loader/NativeLibraries$NativeLibraryImpl;Ljava/lang/String;ZZ)Z");
#endif /* (17 <= JAVA_SPEC_VERSION) && (JAVA_SPEC_VERSION <= 18) */
				if (NULL == mid) {
					goto _fail;
				}
				vm->nativeLibrariesLoadMethodID = (UDATA)mid;
				Trc_JCL_init_nativeLibrariesLoadMethodID(vmThread, vm->nativeLibrariesLoadMethodID);
#endif /* JAVA_SPEC_VERSION >= 15 */

The method id corresponds to jdk/internal/loader/NativeLibraries.load(Ljdk/internal/loader/NativeLibraries$NativeLibraryImpl;Ljava/lang/String;ZZZ)Z

[mpirvu]

Interesting point:
TR_ResolvedJ9MethodBase::isCompilable(TR_Memory * trMemory) already rejects the following methods (based on name)

"java/security/AccessController.doPrivileged(Ljava/security/PrivilegedAction;Ljava/security/AccessControlContext;)Ljava/lang/Object;",
"java/security/AccessController.doPrivileged(Ljava/security/PrivilegedExceptionAction;Ljava/security/AccessControlContext;)Ljava/lang/Object;",
"java/security/AccessController.doPrivileged(Ljava/security/PrivilegedAction;Ljava/security/AccessControlContext;[Ljava/security/Permission;)Ljava/lang/Object;",
"java/security/AccessController.doPrivileged(Ljava/security/PrivilegedExceptionAction;Ljava/security/AccessControlContext;[Ljava/security/Permission;)Ljava/lang/Object;",

TR_ResolvedJ9Method::isCompilable(TR_Memory * trMemory) first applies the filters from TR_ResolvedJ9MethodBase::isCompilable(trMemory) and filters out
javaVM->doPrivilegedWithContextMethodID1
javaVM->doPrivilegedWithContextMethodID2
javaVM->doPrivilegedWithContextPermissionMethodID1;
javaVM->doPrivilegedWithContextPermissionMethodID2;
which correspond to
doPrivileged(Ljava/security/PrivilegedAction;Ljava/security/AccessControlContext;)Ljava/lang/Object;)
doPrivileged(Ljava/security/PrivilegedExceptionAction;Ljava/security/AccessControlContext;)Ljava/lang/Object;)
"doPrivileged(Ljava/security/PrivilegedAction;Ljava/security/AccessControlContext;[Ljava/security/Permission;)Ljava/lang/Object;)
"doPrivileged(Ljava/security/PrivilegedExceptionAction;Ljava/security/AccessControlContext;[Ljava/security/Permission;)Ljava/lang/Object;)

There are also these two which are not captured by TR_ResolvedJ9Method::isCompilable
doPrivileged(Ljava/security/PrivilegedAction;)Ljava/lang/Object;)
doPrivileged(Ljava/security/PrivilegedExceptionAction;)Ljava/lang/Object;)

So, to recap:

1. We don't need the "doPrivileged" code in TR_ResolvedJ9Method::isCompilable because TR_ResolvedJ9MethodBase::isCompilable() handles those cases already.
2. We may need to add two extra doPrivileged methods in TR_ResolvedJ9MethodBase::isCompilable()

[mpirvu]

Even "jdk/internal/loader/NativeLibraries.load()" is handled by TR_ResolvedJ9MethodBase::isCompilable(TR_Memory * trMemory), so the code can be cleaned-up a lot.

Proposed solution is to simplify TR_ResolvedJ9Method::isCompilable(TR_Memory * trMemory) by eliminating the following code

   /* AOT handles this by having the names in the string compare list */
   J9JavaVM * javaVM = _fe->_jitConfig->javaVM;
   J9JNIMethodID * magic = (J9JNIMethodID *) javaVM->doPrivilegedWithContextMethodID1;
   if (magic && ramMethod() == magic->method)
      return false;

   magic = (J9JNIMethodID *) javaVM->doPrivilegedWithContextMethodID2;
   if (magic && ramMethod() == magic->method)
      return false;

   magic = (J9JNIMethodID *) javaVM->doPrivilegedWithContextPermissionMethodID1;
   if (magic && ramMethod() == magic->method)
      return false;

   magic = (J9JNIMethodID *) javaVM->doPrivilegedWithContextPermissionMethodID2;
   if (magic && ramMethod() == magic->method)
      return false;

   magic = (J9JNIMethodID *) javaVM->nativeLibrariesLoadMethodID;
   if (magic && ramMethod() == magic->method) {
      return false;
   }

[mpirvu]

Attn: @SajinaKandy