Provide function to get/set object tag

This will be needed to properly support classloader identification
in instrumentation requests.

src-disl-agent/jvmtiutil.c

@@ -168,6 +168,31 @@ jvmti_get_system_property_string (
 }
 
 
+/**
+ * Gets tag from the given object. This method can only be called
+ * during the START and LIVE phases.
+ */
+jlong
+jvmti_get_object_tag (jvmtiEnv * jvmti, jobject object) {
+	jlong tag;
+	jvmtiError error = (*jvmti)->GetTag (jvmti, object, &tag);
+	check_jvmti_error (jvmti, error, "failed to get object tag");
+	return tag;
+}
+
+
+/**
+ * Sets a tag to the given object. This method can only be called
+ * during the START and LIVE phases.
+ */
+jlong
+jvmti_set_object_tag (jvmtiEnv * jvmti, jobject object, jlong tag) {
+	jvmtiError error = (*jvmti)->SetTag (jvmti, object, tag);
+	check_jvmti_error (jvmti, error, "failed to set object tag");
+	return tag;
+}
+
+
 /**
  * Reports a JVMTI error and terminates the program. This function implements
  * the slow path of check_jvmti_error() and prints the given error message

src-disl-agent/jvmtiutil.h

@@ -26,6 +26,10 @@ char * jvmti_get_system_property_string (
 	jvmtiEnv * jvmti, const char * name, const char * dflval
 );
 
+jlong jvmti_get_object_tag (jvmtiEnv * jvmti, jobject object);
+
+jlong jvmti_set_object_tag (jvmtiEnv * jvmti, jobject object, jlong tag);
+
 //
 
 void die_with_jvmti_error (