Log (Jikes RVM API)

java.lang.Object
- org.mmtk.utility.Log

```
public class Log
extends Object
```
Error and trace logging.

Field Summary

Fields
Modifier and Type	Field and Description
`private char[]`	`buffer` buffer to store written message until flushing
`private int`	`bufferIndex` location of next character to be written
`private static String`	`HEX_PREFIX` string that prefixes numbers logged in hexadecimal
`private static char[]`	`hexDigitCharacter` map of hexadecimal digit values to their character representations
`private static Log`	`log` log instance used at build time.
`private static int`	`LOG_BITS_IN_HEX_DIGIT` log2 of number of bits represented by a single hexidemimal digit
`private static int`	`LOG_HEX_DIGITS_IN_BYTE` log2 of number of digits in the unsigned hexadecimal representation of a byte
`private static int`	`MESSAGE_BUFFER_SIZE` characters in the write buffer for the caller's message.
`private static char`	`NEW_LINE_CHAR` new line character.
`private boolean`	`overflow` `true` if the buffer has overflown
`private static String`	`OVERFLOW_MESSAGE` message added when the write buffer has overflown
`private static char`	`OVERFLOW_MESSAGE_FIRST_CHAR`
`private static int`	`OVERFLOW_SIZE` characters in the overflow message, including the (optional) final newline
`private char`	`overflowLastChar` The last character that was written by #addToBuffer(char).
`private static int`	`TEMP_BUFFER_SIZE` characters in buffer for building string representations of longs.
`private char[]`	`tempBuffer` buffer for building string representations of longs
`private boolean`	`threadIdFlag` `true` if a thread id will be prepended

Constructor Summary

Constructors
Constructor and Description

Log()
constructor

Constructors
Constructor and Description
`Log()` constructor

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`private static void`	`add(char c)` adds a character to the buffer
`private static void`	`add(String s)` adds a string to the buffer
`private void`	`addToBuffer(char c)` adds a character to the buffer
`private void`	`addToBuffer(String s)` adds a string to the buffer
`static void`	`flush()` flushes the buffer.
`private void`	`flushBuffer()` flushes the buffer
`private static char[]`	`getIntBuffer()`
`private static Log`	`getLog()`
`private char[]`	`getTempBuffer()`
`static void`	`prependThreadId()` Log a thread identifier at the start of the next message flushed.
`private void`	`setThreadIdFlag()` sets the flag so that a thread identifier will be included before the logged message
`static void`	`write(Address a)` writes an address, in hexadecimal.
`static void`	`write(boolean b)` writes a boolean.
`static void`	`write(byte[] b)` writes an array of bytes.
`static void`	`write(char c)` writes a character
`static void`	`write(char[] c)` writes an array of characters
`static void`	`write(char[] c, int len)` writes the start of an array of characters
`static void`	`write(double d)` writes a `double`.
`static void`	`write(double d, int postDecimalDigits)` writes a `double`.
`static void`	`write(Extent e)` writes an extent, in hexadecimal.
`static void`	`write(long l)` writes a long, in decimal.
`static void`	`write(ObjectReference o)` writes an object reference, in hexadecimal.
`static void`	`write(Offset o)` writes an offset, in hexadecimal.
`static void`	`write(String s)` writes a string
`static void`	`write(String s, Address a)` writes a string followed by an address, in hexadecimal.
`static void`	`write(String s, long l)` Write a string followed by a long
`static void`	`write(Word w)` writes a word, in hexadecimal.
`static void`	`writeDec(Word w)` writes a word, in decimal.
`private static void`	`writeHex(Word w, int bytes)` writes a `long` in hexadecimal
`static void`	`writeln()` write a new-line and flushes the buffer
`static void`	`writeln(Address a)` writes an address, in hexadecimal, and a new-line, then flushes the buffer.
`static void`	`writeln(Address a, boolean flush)` writes an address, in hexadecimal, and a new-line, then optionally flushes the buffer.
`static void`	`writeln(boolean b)` writes a boolean and a new-line, then flushes the buffer.
`static void`	`writeln(boolean b, boolean flush)` writes a boolean and a new-line, then optionally flushes the buffer.
`static void`	`writeln(byte[] b)` writes an array of bytes and a new-line, then flushes the buffer.
`static void`	`writeln(byte[] b, boolean flush)` writes an array of bytes and a new-line, then optionally flushes the buffer.
`static void`	`writeln(char c)` writes a character and a new-line, then flushes the buffer.
`static void`	`writeln(char[] ca)` writes an array of characters and a new-line, then flushes the buffer.
`static void`	`writeln(char[] ca, boolean flush)` writes an array of characters and a new-line, then optionally flushes the buffer.
`static void`	`writeln(char[] ca, int len)` writes the start of an array of characters and a new-line, then flushes the buffer.
`static void`	`writeln(char[] ca, int len, boolean flush)` writes the start of an array of characters and a new-line, then optionally flushes the buffer.
`static void`	`writeln(char c, boolean flush)` writes a character and a new-line, then optionally flushes the buffer.
`static void`	`writeln(double d)` writes a `double` and a new-line, then flushes the buffer.
`static void`	`writeln(double d, boolean flush)` writes a `double` and a new-line, then optionally flushes the buffer.
`static void`	`writeln(double d, int postDecimalDigits)` writes a `double` and a new-line, then flushes the buffer.
`static void`	`writeln(double d, int postDecimalDigits, boolean flush)` writes a `double` and a new-line, then optionally flushes the buffer.
`static void`	`writeln(Extent e)` writes an extent, in hexadecimal, and a new-line, then flushes the buffer.
`static void`	`writeln(Extent e, boolean flush)` writes an extent, in hexadecimal, and a new-line, then optionally flushes the buffer.
`static void`	`writeln(long l)` writes a long, in decimal, and a new-line, then flushes the buffer.
`static void`	`writeln(long l, boolean flush)` writes a long, in decimal, and a new-line, then optionally flushes the buffer.
`static void`	`writeln(ObjectReference o)` writes an object reference, in hexadecimal, and a new-line, then flushes the buffer.
`static void`	`writeln(ObjectReference o, boolean flush)` writes an object reference, in hexadecimal, and a new-line, then optionally flushes the buffer.
`static void`	`writeln(Offset o)` writes an offset, in hexadecimal, and a new-line, then flushes the buffer.
`static void`	`writeln(Offset o, boolean flush)` writes an offset, in hexadecimal, and a new-line, then optionally flushes the buffer.
`static void`	`writeln(String s)` writes a string and a new-line, then flushes the buffer.
`static void`	`writeln(String s, Address a)` writes a string followed by a Address
`static void`	`writeln(String s, boolean flush)` writes a string and a new-line, then optionally flushes the buffer.
`static void`	`writeln(String s, long l)`
`static void`	`writeln(Word w)` writes a word, in hexadecimal, and a new-line, then flushes the buffer.
`static void`	`writeln(Word w, boolean flush)` writes a word, in hexadecimal, and a new-line, then optionally flushes the buffer.
`static void`	`writelnNoFlush()` writes a new-line without flushing the buffer
`private static void`	`writelnWithFlush(boolean flush)` writes a new-line and optionally flushes the buffer

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - MESSAGE_BUFFER_SIZE
```
private static final int MESSAGE_BUFFER_SIZE
```
    characters in the write buffer for the caller's message. This does not include characters reserved for the overflow message.
    This needs to be large because Jikes RVM's implementation of Lock.java logs a lot of information when there is potential GC deadlock.
    
    See Also:
    
    Constant Field Values
  - OVERFLOW_MESSAGE
```
private static final String OVERFLOW_MESSAGE
```
    message added when the write buffer has overflown
    
    See Also:
    
    Constant Field Values
  - OVERFLOW_MESSAGE_FIRST_CHAR
```
private static final char OVERFLOW_MESSAGE_FIRST_CHAR
```
  - OVERFLOW_SIZE
```
private static final int OVERFLOW_SIZE
```
    characters in the overflow message, including the (optional) final newline
  - TEMP_BUFFER_SIZE
```
private static final int TEMP_BUFFER_SIZE
```
    characters in buffer for building string representations of longs. A long is a signed 64-bit integer in the range -2^63 to 2^63+1. The number of digits in the decimal representation of 2^63 is ceiling(log10(2^63)) == ceiling(63 * log10(2)) == 19. An extra character may be required for a minus sign (-). So the maximum number of characters is 20.
    
    See Also:
    
    Constant Field Values
  - HEX_PREFIX
```
private static final String HEX_PREFIX
```
    string that prefixes numbers logged in hexadecimal
    
    See Also:
    
    Constant Field Values
  - LOG_BITS_IN_HEX_DIGIT
```
private static final int LOG_BITS_IN_HEX_DIGIT
```
    log2 of number of bits represented by a single hexidemimal digit
    
    See Also:
    
    Constant Field Values
  - LOG_HEX_DIGITS_IN_BYTE
```
private static final int LOG_HEX_DIGITS_IN_BYTE
```
    log2 of number of digits in the unsigned hexadecimal representation of a byte
    
    See Also:
    
    Constant Field Values
  - hexDigitCharacter
```
private static final char[] hexDigitCharacter
```
    map of hexadecimal digit values to their character representations
  - NEW_LINE_CHAR
```
private static final char NEW_LINE_CHAR
```
    new line character. Emitted by writeln methods.
    
    See Also:
    
    Constant Field Values
  - log
```
private static Log log
```
    log instance used at build time.
  - buffer
```
private final char[] buffer
```
    buffer to store written message until flushing
  - bufferIndex
```
private int bufferIndex
```
    location of next character to be written
  - overflow
```
private boolean overflow
```
    true if the buffer has overflown
  - overflowLastChar
```
private char overflowLastChar
```
    The last character that was written by #addToBuffer(char). This is used to check whether we want to newline-terminate the text.
  - threadIdFlag
```
private boolean threadIdFlag
```
    true if a thread id will be prepended
  - tempBuffer
```
private final char[] tempBuffer
```
    buffer for building string representations of longs
- Constructor Detail
  - Log
```
public Log()
```
    constructor
- Method Detail
  - write
```
public static void write(boolean b)
```
    writes a boolean. Either "true" or "false" is logged.
    
    Parameters:
    
    b - boolean value to be logged.
  - write
```
public static void write(char c)
```
    writes a character
    
    Parameters:
    
    c - character to be logged
  - write
```
public static void write(long l)
```
    writes a long, in decimal. The value is not padded and no thousands separator is logged. If the value is negative a leading minus sign (-) is logged.
    
    Parameters:
    
    l - long value to be logged
  - write
```
public static void write(double d)
```
    writes a double. Two digits after the decimal point are always logged. The value is not padded and no thousands separator is used. If the value is negative a leading hyphen-minus (-) is logged. The decimal point is a full stop (.).
    
    Parameters:
    
    d - the double to be logged
  - write
```
public static void write(double d,
                         int postDecimalDigits)
```
    writes a double. The number of digits after the decimal point is determined by postDecimalDigits. The value is not padded and not thousands separator is used. If the value is negative a leading hyphen-minus (-) is logged. The decimal point is a full stop (.) and is logged even if postDecimcalDigits is zero. If d is greater than the largest representable value of type int, it is logged as "TooBig". Similarly, if it is less than the negative of the largest representable value, it is logged as "TooSmall". If d is NaN is is logged as "NaN".
    
    Parameters:
    
    d - the double to be logged
    
    postDecimalDigits - the number of digits to be logged after the decimal point. If less than or equal to zero no digits are logged, but the decimal point is.
  - write
```
public static void write(char[] c)
```
    writes an array of characters
    
    Parameters:
    
    c - the array of characters to be logged
  - write
```
public static void write(char[] c,
                         int len)
```
    writes the start of an array of characters
    
    Parameters:
    
    c - the array of characters
    
    len - the number of characters to be logged, starting with the first character
  - write
```
public static void write(byte[] b)
```
    writes an array of bytes. The bytes are interpretted as characters.
    
    Parameters:
    
    b - the array of bytes to be logged
  - write
```
public static void write(String s)
```
    writes a string
    
    Parameters:
    
    s - the string to be logged
  - write
```
public static void write(Word w)
```
    writes a word, in hexadecimal. It is zero-padded to the size of an address.
    
    Parameters:
    
    w - the word to be logged
  - writeDec
```
public static void writeDec(Word w)
```
    writes a word, in decimal.
    
    Parameters:
    
    w - the word to be logged
  - write
```
public static void write(Address a)
```
    writes an address, in hexadecimal. It is zero-padded.
    
    Parameters:
    
    a - the address to be logged
  - write
```
public static void write(String s,
                         Address a)
```
    writes a string followed by an address, in hexadecimal.
    
    Parameters:
    
    s - the string to be logged
    
    a - the address to be logged
    
    See Also:
    
    write(String), write(Address)
  - write
```
public static void write(String s,
                         long l)
```
    Write a string followed by a long
    
    Parameters:
    
    s - the string to be logged
    
    l - the long to be logged
    
    See Also:
    
    write(String), write(long)
  - write
```
public static void write(ObjectReference o)
```
    writes an object reference, in hexadecimal. It is zero-padded.
    
    Parameters:
    
    o - the object reference to be logged
  - write
```
public static void write(Offset o)
```
    writes an offset, in hexadecimal. It is zero-padded.
    
    Parameters:
    
    o - the offset to be logged
  - write
```
public static void write(Extent e)
```
    writes an extent, in hexadecimal. It is zero-padded.
    
    Parameters:
    
    e - the extent to be logged
  - writeln
```
public static void writeln()
```
    write a new-line and flushes the buffer
  - writeln
```
public static void writeln(boolean b)
```
    writes a boolean and a new-line, then flushes the buffer.
    
    Parameters:
    
    b - boolean value to be logged.
    
    See Also:
    
    write(boolean)
  - writeln
```
public static void writeln(char c)
```
    writes a character and a new-line, then flushes the buffer.
    
    Parameters:
    
    c - character to be logged
    
    See Also:
    
    write(char)
  - writeln
```
public static void writeln(long l)
```
    writes a long, in decimal, and a new-line, then flushes the buffer.
    
    Parameters:
    
    l - long value to be logged
    
    See Also:
    
    write(long)
  - writeln
```
public static void writeln(double d)
```
    writes a double and a new-line, then flushes the buffer.
    
    Parameters:
    
    d - the double to be logged
    
    See Also:
    
    write(double)
  - writeln
```
public static void writeln(double d,
                           int postDecimalDigits)
```
    writes a double and a new-line, then flushes the buffer.
    
    Parameters:
    
    d - the double to be logged
    
    postDecimalDigits - the number of digits to be logged after the decimal point. If less than or equal to zero no digits are logged, but the decimal point is.
    
    See Also:
    
    write(double, int)
  - writeln
```
public static void writeln(char[] ca)
```
    writes an array of characters and a new-line, then flushes the buffer.
    
    Parameters:
    
    ca - the array of characters to be logged
    
    See Also:
    
    write(char [])
  - writeln
```
public static void writeln(char[] ca,
                           int len)
```
    writes the start of an array of characters and a new-line, then flushes the buffer.
    
    Parameters:
    
    ca - the array of characters
    
    len - the number of characters to be logged, starting with the first character
    
    See Also:
    
    write(char[], int)
  - writeln
```
public static void writeln(byte[] b)
```
    writes an array of bytes and a new-line, then flushes the buffer.
    
    Parameters:
    
    b - the array of bytes to be logged
    
    See Also:
    
    write(byte[])
  - writeln
```
public static void writeln(String s)
```
    writes a string and a new-line, then flushes the buffer.
    
    Parameters:
    
    s - the string to be logged
  - writeln
```
public static void writeln(Word w)
```
    writes a word, in hexadecimal, and a new-line, then flushes the buffer.
    
    Parameters:
    
    w - the word to be logged
    
    See Also:
    
    write(Word)
  - writeln
```
public static void writeln(Address a)
```
    writes an address, in hexadecimal, and a new-line, then flushes the buffer.
    
    Parameters:
    
    a - the address to be logged
    
    See Also:
    
    write(Address)
  - writeln
```
public static void writeln(ObjectReference o)
```
    writes an object reference, in hexadecimal, and a new-line, then flushes the buffer.
    
    Parameters:
    
    o - the object reference to be logged
    
    See Also:
    
    write(ObjectReference)
  - writeln
```
public static void writeln(Offset o)
```
    writes an offset, in hexadecimal, and a new-line, then flushes the buffer.
    
    Parameters:
    
    o - the offset to be logged
    
    See Also:
    
    write(Offset)
  - writeln
```
public static void writeln(Extent e)
```
    writes an extent, in hexadecimal, and a new-line, then flushes the buffer.
    
    Parameters:
    
    e - the extent to be logged
    
    See Also:
    
    write(Extent)
  - writelnNoFlush
```
public static void writelnNoFlush()
```
    writes a new-line without flushing the buffer
  - writeln
```
public static void writeln(boolean b,
                           boolean flush)
```
    writes a boolean and a new-line, then optionally flushes the buffer.
    
    Parameters:
    
    b - boolean value to be logged.
    
    flush - if true then flushes the buffer
    
    See Also:
    
    write(boolean)
  - writeln
```
public static void writeln(char c,
                           boolean flush)
```
    writes a character and a new-line, then optionally flushes the buffer.
    
    Parameters:
    
    c - character to be logged
    
    flush - if true then flushes the buffer
    
    See Also:
    
    write(char)
  - writeln
```
public static void writeln(long l,
                           boolean flush)
```
    writes a long, in decimal, and a new-line, then optionally flushes the buffer.
    
    Parameters:
    
    l - long value to be logged
    
    flush - if true then flushes the buffer
    
    See Also:
    
    write(long)
  - writeln
```
public static void writeln(double d,
                           boolean flush)
```
    writes a double and a new-line, then optionally flushes the buffer.
    
    Parameters:
    
    d - the double to be logged
    
    flush - if true then flush the buffer
    
    See Also:
    
    write(double)
  - writeln
```
public static void writeln(double d,
                           int postDecimalDigits,
                           boolean flush)
```
    writes a double and a new-line, then optionally flushes the buffer.
    
    Parameters:
    
    d - the double to be logged
    
    postDecimalDigits - the number of digits to be logged after the decimal point. If less than or equal to zero no digits are logged, but the decimal point is.
    
    flush - if true then flushes the buffer
    
    See Also:
    
    write(double, int)
  - writeln
```
public static void writeln(char[] ca,
                           boolean flush)
```
    writes an array of characters and a new-line, then optionally flushes the buffer.
    
    Parameters:
    
    ca - the array of characters to be logged
    
    flush - if true then flushes the buffer
    
    See Also:
    
    write(char [])
  - writeln
```
public static void writeln(char[] ca,
                           int len,
                           boolean flush)
```
    writes the start of an array of characters and a new-line, then optionally flushes the buffer.
    
    Parameters:
    
    ca - the array of characters
    
    len - the number of characters to be logged, starting with the first character
    
    flush - if true then flushes the buffer
    
    See Also:
    
    write(char[], int)
  - writeln
```
public static void writeln(byte[] b,
                           boolean flush)
```
    writes an array of bytes and a new-line, then optionally flushes the buffer.
    
    Parameters:
    
    b - the array of bytes to be logged
    
    flush - if true then flushes the buffer
    
    See Also:
    
    write(byte[])
  - writeln
```
public static void writeln(String s,
                           boolean flush)
```
    writes a string and a new-line, then optionally flushes the buffer.
    
    Parameters:
    
    s - the string to be logged
    
    flush - if true then flushes the buffer
  - writeln
```
public static void writeln(String s,
                           long l)
```
  - writeln
```
public static void writeln(Word w,
                           boolean flush)
```
    writes a word, in hexadecimal, and a new-line, then optionally flushes the buffer.
    
    Parameters:
    
    w - the word to be logged
    
    flush - if true then flushes the buffer
    
    See Also:
    
    write(Word)
  - writeln
```
public static void writeln(Address a,
                           boolean flush)
```
    writes an address, in hexadecimal, and a new-line, then optionally flushes the buffer.
    
    Parameters:
    
    a - the address to be logged
    
    flush - if true then flushes the buffer
    
    See Also:
    
    write(Address)
  - writeln
```
public static void writeln(ObjectReference o,
                           boolean flush)
```
    writes an object reference, in hexadecimal, and a new-line, then optionally flushes the buffer.
    
    Parameters:
    
    o - the object reference to be logged
    
    flush - if true then flushes the buffer
    
    See Also:
    
    write(ObjectReference)
  - writeln
```
public static void writeln(Offset o,
                           boolean flush)
```
    writes an offset, in hexadecimal, and a new-line, then optionally flushes the buffer.
    
    Parameters:
    
    o - the offset to be logged
    
    flush - if true then flushes the buffer
    
    See Also:
    
    write(Offset)
  - writeln
```
public static void writeln(Extent e,
                           boolean flush)
```
    writes an extent, in hexadecimal, and a new-line, then optionally flushes the buffer.
    
    Parameters:
    
    e - the extent to be logged
    
    flush - if true then flushes the buffer
    
    See Also:
    
    write(Extent)
  - writeln
```
public static void writeln(String s,
                           Address a)
```
    writes a string followed by a Address
    
    Parameters:
    
    s - the string to be logged
    
    a - the Address to be logged
    
    See Also:
    
    write(String), write(Address)
  - prependThreadId
```
public static void prependThreadId()
```
    Log a thread identifier at the start of the next message flushed.
  - flush
```
public static void flush()
```
    flushes the buffer. The buffered effected of writes since the last flush will be logged in one block without output from other thread's logging interleaving.
  - writelnWithFlush
```
private static void writelnWithFlush(boolean flush)
```
    writes a new-line and optionally flushes the buffer
    
    Parameters:
    
    flush - if true the buffer is flushed
  - writeHex
```
private static void writeHex(Word w,
                             int bytes)
```
    writes a long in hexadecimal
    
    Parameters:
    
    w - the Word to be logged
    
    bytes - the number of bytes from the long to be logged. If less than 8 then the least significant bytes are logged and some of the most significant bytes are ignored.
  - add
```
private static void add(char c)
```
    adds a character to the buffer
    
    Parameters:
    
    c - the character to add
  - add
```
private static void add(String s)
```
    adds a string to the buffer
    
    Parameters:
    
    s - the string to add
  - getLog
```
private static Log getLog()
```
  - addToBuffer
```
private void addToBuffer(char c)
```
    adds a character to the buffer
    
    Parameters:
    
    c - the character to add
  - addToBuffer
```
private void addToBuffer(String s)
```
    adds a string to the buffer
    
    Parameters:
    
    s - the string to add
  - flushBuffer
```
private void flushBuffer()
```
    flushes the buffer
  - setThreadIdFlag
```
private void setThreadIdFlag()
```
    sets the flag so that a thread identifier will be included before the logged message
  - getIntBuffer
```
private static char[] getIntBuffer()
```
    Returns:
    
    the buffer for building string representations of integers. There is one of these buffers for each Log instance.
  - getTempBuffer
```
private char[] getTempBuffer()
```
    Returns:
    
    the buffer for building string representations of integers

Class Log

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

MESSAGE_BUFFER_SIZE

OVERFLOW_MESSAGE

OVERFLOW_MESSAGE_FIRST_CHAR

OVERFLOW_SIZE

TEMP_BUFFER_SIZE

HEX_PREFIX

LOG_BITS_IN_HEX_DIGIT

LOG_HEX_DIGITS_IN_BYTE

hexDigitCharacter

NEW_LINE_CHAR

log

buffer

bufferIndex

overflow

overflowLastChar

threadIdFlag

tempBuffer

Constructor Detail

Log

Method Detail

write

write

write

write

write

write

write

write

write

write

writeDec

write

write

write

write

write

write

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writelnNoFlush

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

writeln

prependThreadId

flush

writelnWithFlush

writeHex

add