--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/logging/logMessage.hpp	Mon May 09 15:46:12 2016 +0200
@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2016, 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.
+ *
+ */
+#ifndef SHARE_VM_LOGGING_LOGMESSAGE_HPP
+#define SHARE_VM_LOGGING_LOGMESSAGE_HPP
+
+#include "logging/log.hpp"
+#include "logging/logMessageBuffer.hpp"
+#include "logging/logPrefix.hpp"
+#include "logging/logTag.hpp"
+
+// The LogMessage class represents a multi-part/multi-line message
+// that is guaranteed to be sent and written to the log outputs
+// in a way that prevents interleaving by other log messages.
+//
+// The interface of LogMessage is very similar to the Log class,
+// with printf functions for each level (trace(), debug(), etc).
+// The difference is that these functions will append/write to the
+// LogMessage, which only buffers the message-parts until the whole
+// message is sent to a log (using Log::write). Internal buffers
+// are C heap allocated lazily on first write. LogMessages are
+// automatically written when they go out of scope.
+//
+// Example usage:
+//
+// {
+//   LogMessage(logging) msg;
+//   if (msg.is_debug()) {
+//     msg.debug("debug message");
+//     msg.trace("additional trace information");
+//   }
+// }
+//
+// Log outputs on trace level will see both of the messages above,
+// and the trace line will immediately follow the debug line.
+// They will have identical decorations (apart from level).
+// Log outputs on debug level will see the debug message,
+// but not the trace message.
+//
+#define LogMessage(...) LogMessageImpl<LOG_TAGS(__VA_ARGS__)>
+template <LogTagType T0, LogTagType T1 = LogTag::__NO_TAG, LogTagType T2 = LogTag::__NO_TAG,
+          LogTagType T3 = LogTag::__NO_TAG, LogTagType T4 = LogTag::__NO_TAG, LogTagType GuardTag = LogTag::__NO_TAG>
+class LogMessageImpl : public LogMessageBuffer {
+ private:
+  LogImpl<T0, T1, T2, T3, T4, GuardTag> _log;
+  bool _has_content;
+
+ public:
+  LogMessageImpl() : _has_content(false) {
+  }
+
+  ~LogMessageImpl() {
+    if (_has_content) {
+      flush();
+    }
+  }
+
+  void flush() {
+    _log.write(*this);
+    reset();
+  }
+
+  void reset() {
+    _has_content = false;
+    LogMessageBuffer::reset();
+  }
+
+  ATTRIBUTE_PRINTF(3, 0)
+  void vwrite(LogLevelType level, const char* fmt, va_list args) {
+    if (!_has_content) {
+      _has_content = true;
+      set_prefix(LogPrefix<T0, T1, T2, T3, T4>::prefix);
+    }
+    LogMessageBuffer::vwrite(level, fmt, args);
+  }
+
+#define LOG_LEVEL(level, name) \
+  bool is_##name() const { \
+    return _log.is_level(LogLevel::level); \
+  }
+  LOG_LEVEL_LIST
+#undef LOG_LEVEL
+};
+
+#endif // SHARE_VM_LOGGING_LOGMESSAGE_HPP