javax.realtime.device

Interface RawByteWriter

All Superinterfaces:

RawMemory

All Known Subinterfaces:

RawByte

public interface RawByteWriter
extends RawMemory

A marker for a byte accessor object encapsulating the protocol for writing bytes to raw memory. A byte accessor can always access at least one byte. Each byte is transferred in a single atomic operation. Groups of bytes may be transferred together; however, this is not required.

Objects of this type are created with the method RawMemoryFactory.createRawByteWriter(javax.realtime.device.RawMemoryRegion, long, int, int) and RawMemoryFactory.createRawByte(javax.realtime.device.RawMemoryRegion, long, int, int). Each object references a range of elements in the RawMemoryRegion starting at the base address provided to the factory method. The size provided to the factory method determines the number of elements accessible.

Caching of the memory access is controlled by the factory that created this object. If the memory is not cached, this method guarantees serialized access. In other words, the memory access at the memory occurs in the same order as in the program. Multiple writes to the same location may not be coalesced.

Since:

RTSJ 2.0

Method Summary

Modifier and Type	Method and Description
int	set(int offset, byte[] values) Copies from values to the memory region, from index start to elements where the nth element is at the address base address + (offset + n) × stride × element size in bytes.
int	set(int offset, byte[] values, int start, int count) Copies values to the memory region, where offset is first byte in the memory region to write and start is the first index in values from which to read.
void	setByte(byte value) Sets the value at the first position referenced by this instance, i.e., the value at its start address.
void	setByte(int offset, byte value) Sets the value of the nth element referenced by this instance, where n is offset and the address is base address + offset × size of Byte.

Methods inherited from interface javax.realtime.device.RawMemory

getAddress, getSize, getStride

Method Detail

setByte

void setByte(byte value)

Sets the value at the first position referenced by this instance, i.e., the value at its start address. This operation must be atomic with respect to all other raw memory accesses to the address.

Parameters:

value - The new value for the element.

setByte

void setByte(int offset,
             byte value)
      throws OffsetOutOfBoundsException

Sets the value of the n^th element referenced by this instance, where n is offset and the address is base address + offset × size of Byte. This operation must be atomic with respect to all other raw memory accesses to the address. When an exception is thrown, no data is transferred.

Parameters:

offset - of byte in the memory region.

value - The new value for the element.

Throws:

OffsetOutOfBoundsException - when offset is negative or greater than or equal to the number of elements in the raw memory region.

set

int set(int offset,
        byte[] values)
 throws OffsetOutOfBoundsException,
        java.lang.NullPointerException

Copies from values to the memory region, from index start to elements where the n^th element is at the address base address + (offset + n) × stride × element size in bytes. Only the bytes in the intersection of values and the end of the memory region are transferred. When an exception is thrown, no data is transferred.

Parameters:

offset - of first byte in the memory region to be set.

values - The source of the data to write.

Returns:

the number of elements actually transferred to values.

Throws:

OffsetOutOfBoundsException - when offset is negative or greater than or equal to the number of elements in the raw memory region.

java.lang.NullPointerException - when values is null.

set

int set(int offset,
        byte[] values,
        int start,
        int count)
 throws OffsetOutOfBoundsException,
        java.lang.ArrayIndexOutOfBoundsException,
        java.lang.IllegalArgumentException,
        java.lang.NullPointerException

Copies values to the memory region, where offset is first byte in the memory region to write and start is the first index in values from which to read. The number of bytes transferred is the minimum of count, the size of the memory region minus offset, and length of values minus start. When an exception is thrown, no data is transferred.

Parameters:

offset - of the first byte in the memory region to set.

values - The array from which to retrieve the bytes.

start - The first index in array to copy.

count - The maximum number of bytes to copy.

Returns:

the number of bytes actually transferred.

Throws:

OffsetOutOfBoundsException - when offset is negative or either offset or offset + count is greater than or equal to the size of this raw memory area.

java.lang.ArrayIndexOutOfBoundsException - when start is negative or either start or start + count is greater than or equal to the size of values.

java.lang.NullPointerException - when values is null.

java.lang.IllegalArgumentException