1 /* 2 * Copyright (c) 2015, 2016, 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_LOG_HPP 25 #define SHARE_VM_LOGGING_LOG_HPP 26 27 #include "logging/logLevel.hpp" 28 #include "logging/logPrefix.hpp" 29 #include "logging/logTagSet.hpp" 30 #include "logging/logTag.hpp" 31 #include "memory/allocation.hpp" 32 #include "runtime/os.hpp" 33 #include "utilities/debug.hpp" 34 #include "utilities/ostream.hpp" 35 36 // 37 // Logging macros 38 // 39 // Usage: 40 // log_<level>(<comma separated log tags>)(<printf-style log arguments>); 41 // e.g. 42 // log_debug(logging)("message %d", i); 43 // 44 // Note that these macros will not evaluate the arguments unless the logging is enabled. 45 // 46 #define log_error(...) (!log_is_enabled(Error, __VA_ARGS__)) ? (void)0 : LogImpl<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Error> 47 #define log_warning(...) (!log_is_enabled(Warning, __VA_ARGS__)) ? (void)0 : LogImpl<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Warning> 48 #define log_info(...) (!log_is_enabled(Info, __VA_ARGS__)) ? (void)0 : LogImpl<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Info> 49 #define log_debug(...) (!log_is_enabled(Debug, __VA_ARGS__)) ? (void)0 : LogImpl<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Debug> 50 #define log_trace(...) (!log_is_enabled(Trace, __VA_ARGS__)) ? (void)0 : LogImpl<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Trace> 51 52 // Macros for logging that should be excluded in product builds. 53 // Available for levels Info, Debug and Trace. Includes test macro that 54 // evaluates to false in product builds. 55 #ifndef PRODUCT 56 #define log_develop_info(...) (!log_is_enabled(Info, __VA_ARGS__)) ? (void)0 : LogImpl<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Info> 57 #define log_develop_debug(...) (!log_is_enabled(Debug, __VA_ARGS__)) ? (void)0 : LogImpl<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Debug> 58 #define log_develop_trace(...) (!log_is_enabled(Trace, __VA_ARGS__)) ? (void)0 : LogImpl<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Trace> 59 #define log_develop_is_enabled(level, ...) log_is_enabled(level, __VA_ARGS__) 60 #else 61 #define DUMMY_ARGUMENT_CONSUMER(...) 62 #define log_develop_info(...) DUMMY_ARGUMENT_CONSUMER 63 #define log_develop_debug(...) DUMMY_ARGUMENT_CONSUMER 64 #define log_develop_trace(...) DUMMY_ARGUMENT_CONSUMER 65 #define log_develop_is_enabled(...) false 66 #endif 67 68 // Convenience macro to test if the logging is enabled on the specified level for given tags. 69 #define log_is_enabled(level, ...) (LogImpl<LOG_TAGS(__VA_ARGS__)>::is_level(LogLevel::level)) 70 71 // 72 // Log class for more advanced logging scenarios. 73 // Has printf-style member functions for each log level (trace(), debug(), etc). 74 // 75 // Also has outputStream compatible API for the different log-levels. 76 // The streams are resource allocated when requested and are accessed through 77 // calls to <level>_stream() functions (trace_stream(), debug_stream(), etc). 78 // 79 // Example usage: 80 // Log(logging) log; 81 // if (log.is_debug()) { 82 // ... 83 // log.debug("result = %d", result).trace(" tracing info"); 84 // obj->print_on(log.debug_stream()); 85 // } 86 // 87 #define Log(...) LogImpl<LOG_TAGS(__VA_ARGS__)> 88 89 template <LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag> 90 class LogImpl; 91 92 // Non-template helper class for implementing write-slowpath in cpp 93 class LogWriteHelper : AllStatic { 94 private: 95 96 template <LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag> 97 friend class LogImpl; 98 99 ATTRIBUTE_PRINTF(6, 0) 100 static void write_large(LogTagSet& lts, 101 LogLevelType level, 102 const char* prefix, 103 size_t prefix_len, 104 size_t msg_len, 105 const char* fmt, 106 va_list args); 107 }; 108 109 // 110 // Log class that embeds both log tags and a log level. 111 // 112 // The class provides a way to write the tags and log level once, 113 // so that redundant specification of tags or levels can be avoided. 114 // 115 // Example usage: 116 // LogTarget(Debug, gc) out; 117 // if (out.is_enabled()) { 118 // ... 119 // out.print("Worker: %u", i); 120 // out.print(" data: %d", x); 121 // ... 122 // print_stats(out.stream()); 123 // } 124 // 125 #define LogTarget(level, ...) LogTargetImpl<LogLevel::level, LOG_TAGS(__VA_ARGS__)> 126 127 template <LogTagType T0, LogTagType T1 = LogTag::__NO_TAG, LogTagType T2 = LogTag::__NO_TAG, LogTagType T3 = LogTag::__NO_TAG, 128 LogTagType T4 = LogTag::__NO_TAG, LogTagType GuardTag = LogTag::__NO_TAG> 129 class LogImpl VALUE_OBJ_CLASS_SPEC { 130 private: 131 static const size_t LogBufferSize = 512; 132 public: 133 // Make sure no more than the maximum number of tags have been given. 134 // The GuardTag allows this to be detected if/when it happens. If the GuardTag 135 // is not __NO_TAG, the number of tags given exceeds the maximum allowed. 136 STATIC_ASSERT(GuardTag == LogTag::__NO_TAG); // Number of logging tags exceeds maximum supported! 137 138 // Empty constructor to avoid warnings on MSVC about unused variables 139 // when the log instance is only used for static functions. 140 LogImpl() { 141 } 142 143 static bool is_level(LogLevelType level) { 144 return LogTagSetMapping<T0, T1, T2, T3, T4>::tagset().is_level(level); 145 } 146 147 ATTRIBUTE_PRINTF(2, 3) 148 static void write(LogLevelType level, const char* fmt, ...) { 149 va_list args; 150 va_start(args, fmt); 151 vwrite(level, fmt, args); 152 va_end(args); 153 }; 154 155 template <LogLevelType Level> 156 ATTRIBUTE_PRINTF(1, 2) 157 static void write(const char* fmt, ...) { 158 va_list args; 159 va_start(args, fmt); 160 vwrite(Level, fmt, args); 161 va_end(args); 162 }; 163 164 ATTRIBUTE_PRINTF(2, 0) 165 static void vwrite(LogLevelType level, const char* fmt, va_list args) { 166 char buf[LogBufferSize]; 167 va_list saved_args; // For re-format on buf overflow. 168 va_copy(saved_args, args); 169 size_t prefix_len = LogPrefix<T0, T1, T2, T3, T4>::prefix(buf, sizeof(buf)); 170 // Check that string fits in buffer; resize buffer if necessary 171 int ret = os::log_vsnprintf(buf + prefix_len, sizeof(buf) - prefix_len, fmt, args); 172 assert(ret >= 0, "Log message buffer issue"); 173 size_t msg_len = ret; 174 LogTagSet& lts = LogTagSetMapping<T0, T1, T2, T3, T4>::tagset(); 175 if (msg_len >= sizeof(buf)) { 176 LogWriteHelper::write_large(lts, level, buf, prefix_len, msg_len, fmt, saved_args); 177 } else { 178 lts.log(level, buf); 179 } 180 va_end(saved_args); 181 } 182 183 #define LOG_LEVEL(level, name) ATTRIBUTE_PRINTF(2, 0) \ 184 LogImpl& v##name(const char* fmt, va_list args) { \ 185 vwrite(LogLevel::level, fmt, args); \ 186 return *this; \ 187 } \ 188 LogImpl& name(const char* fmt, ...) ATTRIBUTE_PRINTF(2, 3) { \ 189 va_list args; \ 190 va_start(args, fmt); \ 191 vwrite(LogLevel::level, fmt, args); \ 192 va_end(args); \ 193 return *this; \ 194 } \ 195 static bool is_##name() { \ 196 return is_level(LogLevel::level); \ 197 } \ 198 static outputStream* name##_stream() { \ 199 return new logStream(write<LogLevel::level>); \ 200 } 201 LOG_LEVEL_LIST 202 #undef LOG_LEVEL 203 }; 204 205 // Combines logging tags and a logging level. 206 template <LogLevelType level, LogTagType T0, LogTagType T1 = LogTag::__NO_TAG, LogTagType T2 = LogTag::__NO_TAG, 207 LogTagType T3 = LogTag::__NO_TAG, LogTagType T4 = LogTag::__NO_TAG, LogTagType GuardTag = LogTag::__NO_TAG> 208 class LogTargetImpl { 209 public: 210 // Empty constructor to avoid warnings on MSVC about unused variables 211 // when the log instance is only used for static functions. 212 LogTargetImpl() { 213 } 214 215 static bool is_enabled() { 216 return LogImpl<T0, T1, T2, T3, T4, GuardTag>::is_level(level); 217 } 218 219 static void print(const char* fmt, ...) ATTRIBUTE_PRINTF(1, 2) { 220 va_list args; 221 va_start(args, fmt); 222 LogImpl<T0, T1, T2, T3, T4, GuardTag>::vwrite(level, fmt, args); 223 va_end(args); 224 } 225 226 static outputStream* stream() { 227 return new logStream(&LogImpl<T0, T1, T2, T3, T4, GuardTag>::template write<level>); 228 } 229 }; 230 231 #endif // SHARE_VM_LOGGING_LOG_HPP