javax.realtime
Class RawMemoryAccess

java.lang.Object
  javax.realtime.RawMemoryAccess

Direct Known Subclasses:

RawMemoryFloatAccess

public class RawMemoryAccess

extends Object

A class permitting access to specific memory offsets within the process address space.

jRate programs should refer to RealtimeSystem's BYTE_ORDER field to determine if they are running on big-endian or little-endian systems.

Raw memory areas cannot contain references to Java objects.

Since:

0.3.8

Author:

Morgan Deters

Constructor Summary

RawMemoryAccess(Object type, long size)
Constructs a raw memory accessor associated to a memory area of the given memory type and size.

RawMemoryAccess(Object type, long base, long size)
Constructs a raw memory accessor associated to a memory area of the given memory type and size, based at the given offset.

Method Summary

byte	getByte(long offset) Get the byte at the given offset.
void	getBytes(long offset, byte[] bytes, int low, int number) Get a consecutive sequence of bytes at the given offset.
int	getInt(long offset) Get the int at the given offset.
void	getInts(long offset, int[] ints, int low, int number) Get a consecutive sequence of ints at the given offset.
long	getLong(long offset) Get the long at the given offset.
void	getLongs(long offset, long[] longs, int low, int number) Get a consecutive sequence of longs at the given offset.
long	getMappedAddress() Returns the virtual memory location at which this physical memory area is mapped.
short	getShort(long offset) Get the short at the given offset.
void	getShorts(long offset, short[] shorts, int low, int number) Get a consecutive sequence of shorts at the given offset.
long	map() Map the physical memory range into virtual memory.
long	map(long base) Map the physical memory range into virtual memory.
long	map(long base, long size) Map the physical memory range into virtual memory.
void	setByte(long offset, byte value) Set the byte at the given offset.
void	setBytes(long offset, byte[] bytes, int low, int number) Set a consecutive sequence of bytes at the given offset.
void	setInt(long offset, int value) Set the int at the given offset.
void	setInts(long offset, int[] ints, int low, int number) Set a consecutive sequence of ints at the given offset.
void	setLong(long offset, long value) Set the long at the given offset.
void	setLongs(long offset, long[] longs, int low, int number) Set a consecutive sequence of longs at the given offset.
void	setShort(long offset, short value) Set the short at the given offset.
void	setShorts(long offset, short[] shorts, int low, int number) Set a consecutive sequence of shorts at the given offset.
void	unmap() Unmap the physical memory range from virtual memory.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RawMemoryAccess

public RawMemoryAccess(Object type,
                       long size)

Constructs a raw memory accessor associated to a memory area of the given memory type and size.

Parameters:

type - the memory type

size - the size of the memory area

Throws:

SecurityException - the current execution context does not have permission to access physical memory, or memory of the given type

SizeOutOfBoundsException - the size is negative or too large

UnsupportedPhysicalMemoryException - the hardware does not support this type of memory

MemoryTypeConflictException - the type parameter's attributes conflict with each other

OutOfMemoryError - the requested type of memory exists, but there is not enough of it to satisfy the request

RawMemoryAccess

public RawMemoryAccess(Object type,
                       long base,
                       long size)

Constructs a raw memory accessor associated to a memory area of the given memory type and size, based at the given offset.

Parameters:

type - the memory type

base - the base offset of the memory area

size - the size of the memory area

Throws:

SecurityException - the current execution context does not have permission to access physical memory, or memory of the given type

OffsetOutOfBoundsException - the address is invalid

SizeOutOfBoundsException - the size is negative or too large

UnsupportedPhysicalMemoryException - the hardware does not support this type of memory

MemoryTypeConflictException - the type parameter's attributes conflict with each other or with the specified base offset

OutOfMemoryError - the requested type of memory exists, but there is not enough of it to satisfy the request

Method Detail

getByte

public byte getByte(long offset)

Get the byte at the given offset.

Parameters:

offset - the memory offset to access

Returns:

the byte at the given offset

Throws:

OffsetOutOfBoundsException - the given offset is negative or outside the range of this raw memory area

SizeOutOfBoundsException - satisfying the request would require accessing storage beyond the end of the memory area

getBytes

public void getBytes(long offset,
                     byte[] bytes,
                     int low,
                     int number)

Get a consecutive sequence of bytes at the given offset.

Parameters:

offset - the memory offset to access

bytes - the array to copy bytes into

low - the offset into the array at which to start copying

number - the number of bytes to copy

Throws:

OffsetOutOfBoundsException - the given offset is negative or outside the range of this raw memory area

SizeOutOfBoundsException - satisfying the request would require accessing storage beyond the end of the memory area

getInt

public int getInt(long offset)

Get the int at the given offset.

Parameters:

offset - the memory offset to access

Returns:

the int at the given offset

Throws:

OffsetOutOfBoundsException - the given offset is negative or outside the range of this raw memory area

SizeOutOfBoundsException - satisfying the request would require accessing storage beyond the end of the memory area

getInts

public void getInts(long offset,
                    int[] ints,
                    int low,
                    int number)

Get a consecutive sequence of ints at the given offset.

Parameters:

offset - the memory offset to access

ints - the array to copy ints into

low - the offset into the array at which to start copying

number - the number of ints to copy

Throws:

OffsetOutOfBoundsException - the given offset is negative or outside the range of this raw memory area

SizeOutOfBoundsException - satisfying the request would require accessing storage beyond the end of the memory area

getLong

public long getLong(long offset)

Get the long at the given offset.

Parameters:

offset - the memory offset to access

Returns:

the long at the given offset

Throws:

OffsetOutOfBoundsException - the given offset is negative or outside the range of this raw memory area

SizeOutOfBoundsException - satisfying the request would require accessing storage beyond the end of the memory area

getLongs

public void getLongs(long offset,
                     long[] longs,
                     int low,
                     int number)

Get a consecutive sequence of longs at the given offset.

Parameters:

offset - the memory offset to access

longs - the array to copy longs into

low - the offset into the array at which to start copying

number - the number of longs to copy

Throws:

OffsetOutOfBoundsException - the given offset is negative or outside the range of this raw memory area

SizeOutOfBoundsException - satisfying the request would require accessing storage beyond the end of the memory area

getShort

public short getShort(long offset)

Get the short at the given offset.

Parameters:

offset - the memory offset to access

Returns:

the short at the given offset

Throws:

OffsetOutOfBoundsException - the given offset is negative or outside the range of this raw memory area

SizeOutOfBoundsException - satisfying the request would require accessing storage beyond the end of the memory area

getShorts

public void getShorts(long offset,
                      short[] shorts,
                      int low,
                      int number)

Get a consecutive sequence of shorts at the given offset.

Parameters:

offset - the memory offset to access

shorts - the array to copy shorts into

low - the offset into the array at which to start copying

number - the number of shorts to copy

Throws:

OffsetOutOfBoundsException - the given offset is negative or outside the range of this raw memory area

SizeOutOfBoundsException - satisfying the request would require accessing storage beyond the end of the memory area

setByte

public void setByte(long offset,
                    byte value)

Set the byte at the given offset.

Parameters:

offset - the memory offset to access

value - the value to assign the byte in memory

Throws:

OffsetOutOfBoundsException - the given offset is negative or outside the range of this raw memory area

SizeOutOfBoundsException - satisfying the request would require accessing storage beyond the end of the memory area

setBytes

public void setBytes(long offset,
                     byte[] bytes,
                     int low,
                     int number)

Set a consecutive sequence of bytes at the given offset.

Parameters:

offset - the memory offset to access

bytes - the array to copy bytes from

low - the offset into the array at which to start copying

number - the number of bytes to copy

Throws:

OffsetOutOfBoundsException - the given offset is negative or outside the range of this raw memory area

SizeOutOfBoundsException - satisfying the request would require accessing storage beyond the end of the memory area

setInt

public void setInt(long offset,
                   int value)

Set the int at the given offset.

Parameters:

offset - the memory offset to access

value - the value to assign the int in memory

Throws:

OffsetOutOfBoundsException - the given offset is negative or outside the range of this raw memory area

SizeOutOfBoundsException - satisfying the request would require accessing storage beyond the end of the memory area

setInts

public void setInts(long offset,
                    int[] ints,
                    int low,
                    int number)

Set a consecutive sequence of ints at the given offset.

Parameters:

offset - the memory offset to access

ints - the array to copy ints from

low - the offset into the array at which to start copying

number - the number of ints to copy

Throws:

OffsetOutOfBoundsException - the given offset is negative or outside the range of this raw memory area

SizeOutOfBoundsException - satisfying the request would require accessing storage beyond the end of the memory area

setLong

public void setLong(long offset,
                    long value)

Set the long at the given offset.

Parameters:

offset - the memory offset to access

value - the value to assign the long in memory

Throws:

OffsetOutOfBoundsException - the given offset is negative or outside the range of this raw memory area

SizeOutOfBoundsException - satisfying the request would require accessing storage beyond the end of the memory area

setLongs

public void setLongs(long offset,
                     long[] longs,
                     int low,
                     int number)

Set a consecutive sequence of longs at the given offset.

Parameters:

offset - the memory offset to access

longs - the array to copy longs from

low - the offset into the array at which to start copying

number - the number of longs to copy

Throws:

OffsetOutOfBoundsException - the given offset is negative or outside the range of this raw memory area

SizeOutOfBoundsException - satisfying the request would require accessing storage beyond the end of the memory area

setShort

public void setShort(long offset,
                     short value)

Set the short at the given offset.

Parameters:

offset - the memory offset to access

value - the value to assign the short in memory

Throws:

OffsetOutOfBoundsException - the given offset is negative or outside the range of this raw memory area

SizeOutOfBoundsException - satisfying the request would require accessing storage beyond the end of the memory area

setShorts

public void setShorts(long offset,
                      short[] shorts,
                      int low,
                      int number)

Set a consecutive sequence of shorts at the given offset.

Parameters:

offset - the memory offset to access

shorts - the array to copy shorts from

low - the offset into the array at which to start copying

number - the number of shorts to copy

Throws:

OffsetOutOfBoundsException - the given offset is negative or outside the range of this raw memory area

SizeOutOfBoundsException - satisfying the request would require accessing storage beyond the end of the memory area

getMappedAddress

public long getMappedAddress()

Returns the virtual memory location at which this physical memory area is mapped.

Returns:

the virtual memory location to which this physical memory area is mapped

Throws:

IllegalStateException - if this RawMemoryAccess is in an unmapped state

map

public long map()

Map the physical memory range into virtual memory.

Returns:

the base address of the mapped region in virtual memory

Throws:

OutOfMemoryError - there is insufficient free virtual memory at the specified address

map

public long map(long base)

Map the physical memory range into virtual memory.

Parameters:

base - the virtual address to map at

Returns:

the base address of the mapped region in virtual memory

Throws:

OutOfMemoryError - there is insufficient free virtual memory at the specified address

IllegalArgumentException - size is negative, or base is an invalid virtual address

map

public long map(long base,
                long size)

Map the physical memory range into virtual memory.

Parameters:

base - the virtual address to map at

size - the size of the block to map

Returns:

the base address of the mapped region in virtual memory

Throws:

OutOfMemoryError - there is insufficient free virtual memory at the specified address

IllegalArgumentException - size is negative, or base is an invalid virtual address

unmap

public void unmap()

Unmap the physical memory range from virtual memory.