Services (Jikes RVM API)

java.lang.Object
- org.jikesrvm.util.Services

```
public class Services
extends Object
```
Various service utilities. This is a common place for some shared utility routines

Field Summary

Fields
Modifier and Type	Field and Description
`private static char[]`	`dumpBuffer` Pre-allocate the dump buffer, since dump() might get called inside GC.
`private static int`	`dumpBufferLock`
`private static Offset`	`dumpBufferLockOffset` Reset at boot time.
`private static char[]`	`hexDigitCharacter` A map of hexadecimal digit values to their character representations.
`private static int`	`INT_BUFFER_SIZE` How many characters we need to have in a buffer for building string representations of `long`s, such as `intBuffer`.
`private static char[]`	`intBuffer` A buffer for building string representations of `long`s
`private static int`	`intBufferLock` A lock for `intBuffer`
`private static Offset`	`intBufferLockOffset` The offset of `intBufferLock` in this class's TIB.
`static int`	`MAX_DUMP_LEN` Biggest buffer you would possibly need for `RVMThread.dump(char[], int)` Modify this if you modify that method.

Constructor Summary

Constructors
Constructor and Description

Services()

Constructors
Constructor and Description
`Services()`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static String`	`addressAsHexString(Address addr)` Format a 32/64 bit number as "0x" followed by 8/16 hex digits.
`static void`	`boot()` Called during the boot sequence, any time before we go multi-threaded.
`static void`	`breakStub()`
`static byte[]`	`getArrayNoBarrier(byte[][] src, int index)` Gets an element of an array of byte arrays without causing the potential thread switch point that array accesses normally cause.
`static byte`	`getArrayNoBarrier(byte[] src, int index)` Gets an element of a byte array without invoking any read barrier or bounds check.
`static char`	`getArrayNoBarrier(char[] src, int index)` Gets an element of a char array without invoking any read barrier or performing bounds check.
`static int`	`getArrayNoBarrier(int[] src, int index)` Gets an element of an int array without invoking any read barrier or performing bounds checks.
`static Object`	`getArrayNoBarrier(Object[] src, int index)` Gets an element of an Object array without invoking any read barrier or performing bounds checks.
`static String`	`getHexString(int i, boolean blank)`
`static char[]`	`grabDumpBuffer()`
`private static char[]`	`grabIntBuffer()` Gets exclusive access to `intBuffer`, the buffer for building string representations of integers.
`static String`	`intAsHexString(int number)` Format a 32 bit number as "0x" followed by 8 hex digits.
`static String`	`longAsHexString(long number)` Format a 64 bit number as "0x" followed by 16 hex digits.
`static void`	`percentage(int numerator, int denominator, String quantity)`
`(package private) static void`	`percentage(long numerator, long denominator, String quantity)`
`(package private) static void`	`print(int i)`
`(package private) static void`	`print(String s)`
`(package private) static void`	`print(String s, int i)`
`(package private) static void`	`println()`
`(package private) static void`	`println(int i)`
`(package private) static void`	`println(String s)`
`(package private) static void`	`println(String s, int i)`
`static void`	`releaseDumpBuffer()`
`private static void`	`releaseIntBuffer()` Release `intBuffer`, the buffer for building string representations of integers.
`static void`	`setArrayNoBarrier(char[] dst, int index, char value)` Sets an element of a char array without invoking any write barrier.
`static void`	`setArrayUninterruptible(Object[] dst, int index, Object value)` Sets an element of a object array without possibly losing control.
`static int`	`sprintf(char[] dest, int destOffset, char c)`
`static int`	`sprintf(char[] dest, int destOffset, char[] src)`
`static int`	`sprintf(char[] dest, int destOffset, char[] src, int srcStart, int srcEnd)` Copies characters from `src` into the destination character array `dest`.
`static int`	`sprintf(char[] dest, int offset, long l)` Copy the printed decimal representation of a long into a character array.
`static int`	`sprintf(char[] dest, int destOffset, String s)` Copy a String into a character array.

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

- Field Detail
  - MAX_DUMP_LEN
```
public static final int MAX_DUMP_LEN
```
    Biggest buffer you would possibly need for RVMThread.dump(char[], int) Modify this if you modify that method.
    
    See Also:
    
    Constant Field Values
  - dumpBuffer
```
private static final char[] dumpBuffer
```
    Pre-allocate the dump buffer, since dump() might get called inside GC.
  - dumpBufferLock
```
private static int dumpBufferLock
```
  - dumpBufferLockOffset
```
private static Offset dumpBufferLockOffset
```
    Reset at boot time.
  - hexDigitCharacter
```
private static final char[] hexDigitCharacter
```
    A map of hexadecimal digit values to their character representations.
    XXX We currently only use '0' through '9'. The rest are here pending possibly merging this code with the similar code in Log.java, or breaking this code out into a separate utility class.
  - INT_BUFFER_SIZE
```
private static final int INT_BUFFER_SIZE
```
    How many characters we need to have in a buffer for building string representations of longs, such as intBuffer. 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
  - intBuffer
```
private static final char[] intBuffer
```
    A buffer for building string representations of longs
  - intBufferLock
```
private static int intBufferLock
```
    A lock for intBuffer
  - intBufferLockOffset
```
private static Offset intBufferLockOffset
```
    The offset of intBufferLock in this class's TIB. This is set properly at boot time, even though it's a private variable. .
- Constructor Detail
  - Services
```
public Services()
```
- Method Detail
  - boot
```
public static void boot()
```
    Called during the boot sequence, any time before we go multi-threaded. We do this so that we can leave the lockOffsets set to -1 until the VM actually needs the locking (and is running multi-threaded).
  - grabDumpBuffer
```
public static char[] grabDumpBuffer()
```
  - releaseDumpBuffer
```
public static void releaseDumpBuffer()
```
  - sprintf
```
public static int sprintf(char[] dest,
                          int destOffset,
                          String s)
```
    Copy a String into a character array.
    This function may be called during GC and may be used in conjunction with the MMTk Log class. It avoids write barriers and allocation.
    XXX This function should probably be moved to a sensible location where we can use it as a utility. Suggestions welcome.
    
    Parameters:
    
    dest - char array to copy into.
    
    destOffset - Offset into dest where we start copying
    
    s - string to print
    
    Returns:
    
    1 plus the index of the last character written. If we were to write zero characters (which we won't) then we would return offset. This is intended to represent the first unused position in the array dest. However, it also serves as a pseudo-overflow check: It may have the value dest.length, if the array dest was completely filled by the call, or it may have a value greater than dest.length, if the info needs more than dest.length - offset characters of space. If destOffset is negative, return -1. the MMTk Log class).
  - sprintf
```
public static int sprintf(char[] dest,
                          int destOffset,
                          char[] src)
```
  - sprintf
```
public static int sprintf(char[] dest,
                          int destOffset,
                          char[] src,
                          int srcStart,
                          int srcEnd)
```
    Copies characters from src into the destination character array dest.
    The first character to be copied is at index srcBegin; the last character to be copied is at index srcEnd-1. (This is the same convention as followed by java.lang.String#getChars).
    
    Parameters:
    
    dest - char array to copy into.
    
    destOffset - Offset into dest where we start copying
    
    src - Char array to copy from
    
    srcStart - index of the first character of src to copy.
    
    srcEnd - index after the last character of src to copy.
    
    Returns:
    
    1 plus the index of the last character written. If we were to write zero characters (which we won't) then we would return offset. This is intended to represent the first unused position in the array dest. However, it also serves as a pseudo-overflow check: It may have the value dest.length, if the array dest was completely filled by the call, or it may have a value greater than dest.length, if the info needs more than dest.length - offset characters of space. If destOffset is negative, return -1.
  - sprintf
```
public static int sprintf(char[] dest,
                          int destOffset,
                          char c)
```
  - sprintf
```
public static int sprintf(char[] dest,
                          int offset,
                          long l)
```
    Copy the printed decimal representation of a long into a character array. The value is not padded and no thousands separator is copied. If the value is negative a leading minus sign (-) is copied.
    This function may be called during GC and may be used in conjunction with the Log class. It avoids write barriers and allocation.
    XXX This function should probably be moved to a sensible location where we can use it as a utility. Suggestions welcome.
    XXX This method's implementation is stolen from the Log class.
    
    Parameters:
    
    dest - char array to copy into.
    
    offset - Offset into dest where we start copying
    
    l - a whole number to write before the string
    
    Returns:
    
    1 plus the index of the last character written. If we were to write zero characters (which we won't) then we would return offset. This is intended to represent the first unused position in the array dest. However, it also serves as a pseudo-overflow check: It may have the value dest.length, if the array dest was completely filled by the call, or it may have a value greater than dest.length, if the info needs more than dest.length - offset characters of space. If offset is negative, return -1.
  - grabIntBuffer
```
private static char[] grabIntBuffer()
```
    Gets exclusive access to intBuffer, the buffer for building string representations of integers.
    
    Returns:
    
    a buffer to use for building representations of integers (e.g. longs or ints)
  - releaseIntBuffer
```
private static void releaseIntBuffer()
```
    Release intBuffer, the buffer for building string representations of integers.
  - getHexString
```
public static String getHexString(int i,
                                  boolean blank)
```
  - breakStub
```
public static void breakStub()
```
  - println
```
static void println()
```
  - print
```
static void print(String s)
```
  - println
```
static void println(String s)
```
  - print
```
static void print(int i)
```
  - println
```
static void println(int i)
```
  - print
```
static void print(String s,
                  int i)
```
  - println
```
static void println(String s,
                    int i)
```
  - percentage
```
public static void percentage(int numerator,
                              int denominator,
                              String quantity)
```
  - percentage
```
static void percentage(long numerator,
                       long denominator,
                       String quantity)
```
  - intAsHexString
```
public static String intAsHexString(int number)
```
    Format a 32 bit number as "0x" followed by 8 hex digits. Do this without referencing Integer or Character classes, in order to avoid dynamic linking.
    
    Parameters:
    
    number - the number to format
    
    Returns:
    
    a String with the hex representation of the integer
  - longAsHexString
```
public static String longAsHexString(long number)
```
    Format a 64 bit number as "0x" followed by 16 hex digits. Do this without referencing Long or Character classes, in order to avoid dynamic linking.
    
    Parameters:
    
    number - the number to format
    
    Returns:
    
    a String with the hex representation of the long
  - addressAsHexString
```
public static String addressAsHexString(Address addr)
```
    Format a 32/64 bit number as "0x" followed by 8/16 hex digits. Do this without referencing Integer or Character classes, in order to avoid dynamic linking.
    
    Parameters:
    
    addr - The 32/64 bit number to format.
    
    Returns:
    
    a String with the hex representation of an Address
  - setArrayUninterruptible
```
public static void setArrayUninterruptible(Object[] dst,
                                           int index,
                                           Object value)
```
    Sets an element of a object array without possibly losing control. NB doesn't perform checkstore or array index checking.
    
    Parameters:
    
    dst - the destination array
    
    index - the index of the element to set
    
    value - the new value for the element
  - setArrayNoBarrier
```
public static void setArrayNoBarrier(char[] dst,
                                     int index,
                                     char value)
```
    Sets an element of a char array without invoking any write barrier. This method is called by the Log method, as it will be used during garbage collection and needs to manipulate character arrays without causing a write barrier operation.
    
    Parameters:
    
    dst - the destination array
    
    index - the index of the element to set
    
    value - the new value for the element
  - getArrayNoBarrier
```
public static Object getArrayNoBarrier(Object[] src,
                                       int index)
```
    Gets an element of an Object array without invoking any read barrier or performing bounds checks.
    
    Parameters:
    
    src - the source array
    
    index - the natural array index of the element to get
    
    Returns:
    
    the new value of element
  - getArrayNoBarrier
```
public static int getArrayNoBarrier(int[] src,
                                    int index)
```
    Gets an element of an int array without invoking any read barrier or performing bounds checks.
    
    Parameters:
    
    src - the source array
    
    index - the natural array index of the element to get
    
    Returns:
    
    the new value of element
  - getArrayNoBarrier
```
public static char getArrayNoBarrier(char[] src,
                                     int index)
```
    Gets an element of a char array without invoking any read barrier or performing bounds check.
    
    Parameters:
    
    src - the source array
    
    index - the natural array index of the element to get
    
    Returns:
    
    the new value of element
  - getArrayNoBarrier
```
public static byte getArrayNoBarrier(byte[] src,
                                     int index)
```
    Gets an element of a byte array without invoking any read barrier or bounds check.
    
    Parameters:
    
    src - the source array
    
    index - the natural array index of the element to get
    
    Returns:
    
    the new value of element
  - getArrayNoBarrier
```
public static byte[] getArrayNoBarrier(byte[][] src,
                                       int index)
```
    Gets an element of an array of byte arrays without causing the potential thread switch point that array accesses normally cause.
    
    Parameters:
    
    src - the source array
    
    index - the index of the element to get
    
    Returns:
    
    the new value of element

Class Services

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

MAX_DUMP_LEN

dumpBuffer

dumpBufferLock

dumpBufferLockOffset

hexDigitCharacter

INT_BUFFER_SIZE

intBuffer

intBufferLock

intBufferLockOffset

Constructor Detail

Services

Method Detail

boot

grabDumpBuffer

releaseDumpBuffer

sprintf

sprintf

sprintf

sprintf

sprintf

grabIntBuffer

releaseIntBuffer

getHexString

breakStub

println

print

println

print

println

print

println

percentage

percentage

intAsHexString

longAsHexString

addressAsHexString

setArrayUninterruptible

setArrayNoBarrier

getArrayNoBarrier

getArrayNoBarrier

getArrayNoBarrier

getArrayNoBarrier

getArrayNoBarrier