v8/src/log-utils.h

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// Copyright 2006-2009 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef V8_LOG_UTILS_H_
#define V8_LOG_UTILS_H_
#include "allocation.h"
namespace v8 {
namespace internal {
class Logger;
// Functions and data for performing output of log messages.
class Log {
public:
// Performs process-wide initialization.
void Initialize(const char* log_file_name);
// Disables logging, but preserves acquired resources.
void stop() { is_stopped_ = true; }
static bool InitLogAtStart() {
return FLAG_log || FLAG_log_runtime || FLAG_log_api
|| FLAG_log_code || FLAG_log_gc || FLAG_log_handles || FLAG_log_suspect
|| FLAG_log_regexp || FLAG_ll_prof || FLAG_log_internal_timer_events;
}
// Frees all resources acquired in Initialize and Open... functions.
// When a temporary file is used for the log, returns its stream descriptor,
// leaving the file open.
FILE* Close();
// Returns whether logging is enabled.
bool IsEnabled() {
return !is_stopped_ && output_handle_ != NULL;
}
// Size of buffer used for formatting log messages.
static const int kMessageBufferSize = 2048;
// This mode is only used in tests, as temporary files are automatically
// deleted on close and thus can't be accessed afterwards.
static const char* const kLogToTemporaryFile;
static const char* const kLogToConsole;
private:
explicit Log(Logger* logger);
// Opens stdout for logging.
void OpenStdout();
// Opens file for logging.
void OpenFile(const char* name);
// Opens a temporary file for logging.
void OpenTemporaryFile();
// Implementation of writing to a log file.
int WriteToFile(const char* msg, int length) {
ASSERT(output_handle_ != NULL);
size_t rv = fwrite(msg, 1, length, output_handle_);
ASSERT(static_cast<size_t>(length) == rv);
USE(rv);
fflush(output_handle_);
return length;
}
// Whether logging is stopped (e.g. due to insufficient resources).
bool is_stopped_;
// When logging is active output_handle_ is used to store a pointer to log
// destination. mutex_ should be acquired before using output_handle_.
FILE* output_handle_;
// mutex_ is a Mutex used for enforcing exclusive
// access to the formatting buffer and the log file or log memory buffer.
Mutex* mutex_;
// Buffer used for formatting log messages. This is a singleton buffer and
// mutex_ should be acquired before using it.
char* message_buffer_;
Logger* logger_;
friend class Logger;
friend class LogMessageBuilder;
};
// Utility class for formatting log messages. It fills the message into the
// static buffer in Log.
class LogMessageBuilder BASE_EMBEDDED {
public:
// Create a message builder starting from position 0. This acquires the mutex
// in the log as well.
explicit LogMessageBuilder(Logger* logger);
~LogMessageBuilder() { }
// Append string data to the log message.
void Append(const char* format, ...);
// Append string data to the log message.
void AppendVA(const char* format, va_list args);
// Append a character to the log message.
void Append(const char c);
// Append double quoted string to the log message.
void AppendDoubleQuotedString(const char* string);
// Append a heap string.
void Append(String* str);
// Appends an address.
void AppendAddress(Address addr);
void AppendDetailed(String* str, bool show_impl_info);
// Append a portion of a string.
void AppendStringPart(const char* str, int len);
// Write the log message to the log file currently opened.
void WriteToLogFile();
private:
Log* log_;
ScopedLock sl;
int pos_;
};
} } // namespace v8::internal
#endif // V8_LOG_UTILS_H_