--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/jfr/utilities/jfrJavaLog.cpp	Tue May 15 20:24:34 2018 +0200
@@ -0,0 +1,140 @@
+/*
+ * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "jfr/jni/jfrJavaSupport.hpp"
+#include "jfr/utilities/jfrJavaLog.hpp"
+#include "jfr/utilities/jfrLogTagSets.hpp"
+#include "logging/log.hpp"
+#include "logging/logConfiguration.hpp"
+#include "memory/resourceArea.hpp"
+#include "runtime/thread.inline.hpp"
+
+#define JFR_LOG_TAGS_CONCATED(T0, T1, T2, T3, T4, T5, ...)  \
+  T0 ## _ ## T1 ## _ ## T2 ## _ ## T3 ## _ ## T4 ## _ ## T5
+
+enum JfrLogTagSetType {
+#define JFR_LOG_TAG(...) \
+    EXPAND_VARARGS(JFR_LOG_TAGS_CONCATED(__VA_ARGS__, _NO_TAG, _NO_TAG, _NO_TAG, _NO_TAG, _NO_TAG, _NO_TAG)),
+
+    JFR_LOG_TAG_SET_LIST
+
+#undef JFR_LOG_TAG
+    JFR_LOG_TAG_SET_COUNT
+};
+
+struct jfrLogSubscriber
+{
+  jobject log_tag_enum_ref;
+  LogTagSet* log_tag_set;
+};
+
+static jfrLogSubscriber log_tag_sets[JFR_LOG_TAG_SET_COUNT];
+
+static void log_cfg_update(LogLevelType llt, JfrLogTagSetType jflt, TRAPS) {
+  DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(THREAD));
+  if (log_tag_sets[jflt].log_tag_enum_ref == NULL) {
+    return;
+  }
+  jobject lt = log_tag_sets[jflt].log_tag_enum_ref;
+  // set field tagSetLevel to llt value
+  JavaValue result(T_VOID);
+  JfrJavaArguments args(&result);
+  args.set_klass(JfrJavaSupport::klass(lt));
+  args.set_name("tagSetLevel", CHECK);
+  args.set_signature("I", CHECK);
+  args.set_receiver(JfrJavaSupport::resolve_non_null(lt));
+  args.push_int(llt);
+  JfrJavaSupport::set_field(&args, THREAD);
+}
+
+static LogLevelType highest_level(const LogTagSet& lts) {
+  for (size_t i = 0; i < LogLevel::Count; i++) {
+    if (lts.is_level((LogLevelType)i)) {
+      return (LogLevelType)i;
+    }
+  }
+  return LogLevel::Off;
+}
+
+static void log_config_change_internal(bool init, TRAPS) {
+  LogLevelType llt;
+  LogTagSet* lts;
+
+#define JFR_LOG_TAG(...) \
+  lts = &LogTagSetMapping<LOG_TAGS(__VA_ARGS__)>::tagset(); \
+  if (init) { \
+    JfrLogTagSetType tagSetType = \
+      EXPAND_VARARGS(JFR_LOG_TAGS_CONCATED(__VA_ARGS__, _NO_TAG, _NO_TAG, _NO_TAG, _NO_TAG, _NO_TAG, _NO_TAG)); \
+    assert(NULL == log_tag_sets[tagSetType].log_tag_set, "Init JFR LogTagSets twice"); \
+    log_tag_sets[tagSetType].log_tag_set = lts; \
+  } \
+  llt = highest_level(*lts); \
+  log_cfg_update(llt, \
+  EXPAND_VARARGS(JFR_LOG_TAGS_CONCATED(__VA_ARGS__, _NO_TAG, _NO_TAG, _NO_TAG, _NO_TAG, _NO_TAG, _NO_TAG)), THREAD);
+  JFR_LOG_TAG_SET_LIST
+#undef JFR_LOG_TAG
+}
+
+static void log_config_change() {
+  Thread* t = Thread::current();
+  DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(t));
+  log_config_change_internal(false, t);
+}
+
+void JfrJavaLog::subscribe_log_level(jobject log_tag, jint id, TRAPS) {
+  DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(THREAD));
+  static bool subscribed_updates = true;
+  assert(id < JFR_LOG_TAG_SET_COUNT,
+    "LogTag id, java and native not in synch, %d < %d", id, JFR_LOG_TAG_SET_COUNT);
+  assert(NULL == log_tag_sets[id].log_tag_enum_ref, "Subscribing twice");
+  log_tag_sets[id].log_tag_enum_ref = JfrJavaSupport::global_jni_handle(log_tag, THREAD);
+  if (subscribed_updates) {
+    LogConfiguration::register_update_listener(&log_config_change);
+    log_config_change_internal(true, THREAD);
+    subscribed_updates = false;
+  } else {
+    log_config_change_internal(false, THREAD);
+  }
+}
+
+void JfrJavaLog::log(jint tag_set, jint level, jstring message, TRAPS) {
+  DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(THREAD));
+  if (message == NULL) {
+    return;
+  }
+  if (level < (jint)LogLevel::First || level > (jint)LogLevel::Last) {
+    JfrJavaSupport::throw_illegal_argument_exception("LogLevel passed is outside valid range", THREAD);
+    return;
+  }
+  if (tag_set < 0 || tag_set >= (jint)JFR_LOG_TAG_SET_COUNT) {
+    JfrJavaSupport::throw_illegal_argument_exception("LogTagSet id is outside valid range", THREAD);
+    return;
+  }
+  ResourceMark rm(THREAD);
+  const char* const s = JfrJavaSupport::c_str(message, CHECK);
+  assert(s != NULL, "invariant");
+  assert(log_tag_sets[tag_set].log_tag_set != NULL, "LogTagSet is not init");
+  log_tag_sets[tag_set].log_tag_set->log((LogLevelType)level, s);
+}