1 /* 2 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 #ifndef SHARE_VM_LOGGING_LOGPREFIX_HPP 25 #define SHARE_VM_LOGGING_LOGPREFIX_HPP 26 27 #include "gc/shared/gcId.hpp" 28 #include "logging/logTag.hpp" 29 30 // Prefixes prepend each log message for a specified tagset with a given prefix. 31 // These prefixes are written before the log message but after the log decorations. 32 // 33 // A prefix is defined as a function that takes a buffer (with some size) as argument. 34 // This function will be called for each log message, and should write the prefix 35 // to the given buffer. The function should return how many characters it wrote, 36 // which should never exceed the given size. 37 // 38 // List of prefixes for specific tags and/or tagsets. 39 // Syntax: LOG_PREFIX(<name of prefixer function>, LOG_TAGS(<chosen log tags>)) 40 // Where the prefixer function matches the following signature: size_t (*)(char*, size_t) 41 #define LOG_PREFIX_LIST // Currently unused/empty 42 43 // The empty prefix, used when there's no prefix defined. 44 template <LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag = LogTag::__NO_TAG> 45 struct LogPrefix : public AllStatic { 46 STATIC_ASSERT(GuardTag == LogTag::__NO_TAG); 47 static size_t prefix(char* buf, size_t len) { 48 return 0; 49 } 50 }; 51 52 #define LOG_PREFIX(fn, ...) \ 53 template <> struct LogPrefix<__VA_ARGS__> { \ 54 static size_t prefix(char* buf, size_t len) { \ 55 DEBUG_ONLY(buf[0] = '\0';) \ 56 size_t ret = fn(buf, len); \ 57 assert(ret == strlen(buf), "Length mismatch ret (" SIZE_FORMAT ") != buf length (" SIZE_FORMAT ")", ret, strlen(buf)); \ 58 return ret; \ 59 } \ 60 }; 61 LOG_PREFIX_LIST 62 #undef LOG_PREFIX 63 64 #endif // SHARE_VM_LOGGING_LOGPREFIX_HPP