--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/logging/logPrefix.hpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2015, 2017, 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_LOGPREFIX_HPP
+#define SHARE_VM_LOGGING_LOGPREFIX_HPP
+
+#include "gc/shared/gcId.hpp"
+#include "logging/logTag.hpp"
+
+// Prefixes prepend each log message for a specified tagset with a given prefix.
+// These prefixes are written before the log message but after the log decorations.
+//
+// A prefix is defined as a function that takes a buffer (with some size) as argument.
+// This function will be called for each log message, and should write the prefix
+// to the given buffer. The function should return how many characters it wrote,
+// which should never exceed the given size.
+//
+// List of prefixes for specific tags and/or tagsets.
+// Syntax: LOG_PREFIX(<name of prefixer function>, LOG_TAGS(<chosen log tags>))
+// Where the prefixer function matches the following signature: size_t (*)(char*, size_t)
+
+// Prefix function for internal vm test
+DEBUG_ONLY(size_t Test_log_prefix_prefixer(char* buf, size_t len);)
+
+#define LOG_PREFIX_LIST \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, age)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, alloc)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, alloc, region)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, barrier)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, classhisto)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, compaction)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, cpu)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, ergo)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, ergo, cset)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, ergo, heap)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, ergo, ihop)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, ergo, refine)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, heap)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, heap, region)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, freelist)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, humongous)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, ihop)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, liveness)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, marking)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, metaspace)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, mmu)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, phases)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, phases, ref)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, phases, start)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, phases, task)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, plab)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, region)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, remset)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, ref)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, ref, start)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, start)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, stringtable)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, sweep)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, task)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, task, start)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, task, stats)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, task, time)) \
+  DEBUG_ONLY(LOG_PREFIX(Test_log_prefix_prefixer, LOG_TAGS(logging, test))) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, tlab)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, workgang))
+
+
+// The empty prefix, used when there's no prefix defined.
+template <LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag = LogTag::__NO_TAG>
+struct LogPrefix : public AllStatic {
+  STATIC_ASSERT(GuardTag == LogTag::__NO_TAG);
+  static size_t prefix(char* buf, size_t len) {
+    return 0;
+  }
+};
+
+#define LOG_PREFIX(fn, ...) \
+template <> struct LogPrefix<__VA_ARGS__> { \
+  static size_t prefix(char* buf, size_t len) { \
+    size_t ret = fn(buf, len); \
+    /* Either prefix did fit (strlen(buf) == ret && ret < len) */ \
+    /* or the prefix didn't fit in buffer (ret > len && strlen(buf) < len) */ \
+    assert(ret == 0 || strlen(buf) < len, \
+           "Buffer overrun by prefix function."); \
+    assert(ret == 0 || strlen(buf) == ret || ret >= len, \
+           "Prefix function should return length of prefix written," \
+           " or the intended length of prefix if the buffer was too small."); \
+    return ret; \
+  } \
+};
+LOG_PREFIX_LIST
+#undef LOG_PREFIX
+
+#endif // SHARE_VM_LOGGING_LOGPREFIX_HPP