1 // Copyright 2006-2009 the V8 project authors. All rights reserved. 2 // Redistribution and use in source and binary forms, with or without 3 // modification, are permitted provided that the following conditions are 4 // met: 5 // 6 // * Redistributions of source code must retain the above copyright 7 // notice, this list of conditions and the following disclaimer. 8 // * Redistributions in binary form must reproduce the above 9 // copyright notice, this list of conditions and the following 10 // disclaimer in the documentation and/or other materials provided 11 // with the distribution. 12 // * Neither the name of Google Inc. nor the names of its 13 // contributors may be used to endorse or promote products derived 14 // from this software without specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28 #ifndef V8_LOG_UTILS_H_ 29 #define V8_LOG_UTILS_H_ 30 31 #include "allocation.h" 32 33 namespace v8 { 34 namespace internal { 35 36 class Logger; 37 38 // Functions and data for performing output of log messages. 39 class Log { 40 public: 41 // Performs process-wide initialization. 42 void Initialize(); 43 44 // Disables logging, but preserves acquired resources. stop()45 void stop() { is_stopped_ = true; } 46 47 // Frees all resources acquired in Initialize and Open... functions. 48 // When a temporary file is used for the log, returns its stream descriptor, 49 // leaving the file open. 50 FILE* Close(); 51 52 // Returns whether logging is enabled. IsEnabled()53 bool IsEnabled() { 54 return !is_stopped_ && output_handle_ != NULL; 55 } 56 57 // Size of buffer used for formatting log messages. 58 static const int kMessageBufferSize = 2048; 59 60 // This mode is only used in tests, as temporary files are automatically 61 // deleted on close and thus can't be accessed afterwards. 62 static const char* const kLogToTemporaryFile; 63 64 private: 65 explicit Log(Logger* logger); 66 67 // Opens stdout for logging. 68 void OpenStdout(); 69 70 // Opens file for logging. 71 void OpenFile(const char* name); 72 73 // Opens a temporary file for logging. 74 void OpenTemporaryFile(); 75 76 // Implementation of writing to a log file. WriteToFile(const char * msg,int length)77 int WriteToFile(const char* msg, int length) { 78 ASSERT(output_handle_ != NULL); 79 size_t rv = fwrite(msg, 1, length, output_handle_); 80 ASSERT(static_cast<size_t>(length) == rv); 81 USE(rv); 82 fflush(output_handle_); 83 return length; 84 } 85 86 // Whether logging is stopped (e.g. due to insufficient resources). 87 bool is_stopped_; 88 89 // When logging is active output_handle_ is used to store a pointer to log 90 // destination. mutex_ should be acquired before using output_handle_. 91 FILE* output_handle_; 92 93 // Used when low-level profiling is active. 94 FILE* ll_output_handle_; 95 96 // mutex_ is a Mutex used for enforcing exclusive 97 // access to the formatting buffer and the log file or log memory buffer. 98 Mutex* mutex_; 99 100 // Buffer used for formatting log messages. This is a singleton buffer and 101 // mutex_ should be acquired before using it. 102 char* message_buffer_; 103 104 Logger* logger_; 105 106 friend class Logger; 107 friend class LogMessageBuilder; 108 }; 109 110 111 // Utility class for formatting log messages. It fills the message into the 112 // static buffer in Log. 113 class LogMessageBuilder BASE_EMBEDDED { 114 public: 115 // Create a message builder starting from position 0. This acquires the mutex 116 // in the log as well. 117 explicit LogMessageBuilder(Logger* logger); ~LogMessageBuilder()118 ~LogMessageBuilder() { } 119 120 // Append string data to the log message. 121 void Append(const char* format, ...); 122 123 // Append string data to the log message. 124 void AppendVA(const char* format, va_list args); 125 126 // Append a character to the log message. 127 void Append(const char c); 128 129 // Append a heap string. 130 void Append(String* str); 131 132 // Appends an address. 133 void AppendAddress(Address addr); 134 135 void AppendDetailed(String* str, bool show_impl_info); 136 137 // Append a portion of a string. 138 void AppendStringPart(const char* str, int len); 139 140 // Write the log message to the log file currently opened. 141 void WriteToLogFile(); 142 143 private: 144 Log* log_; 145 ScopedLock sl; 146 int pos_; 147 }; 148 149 } } // namespace v8::internal 150 151 #endif // V8_LOG_UTILS_H_ 152