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 from raw memory. A byte accessor can always access at least one byte. Each byte is transfered in a single atomic operation. Groups of bytes may be transfered 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 factor method determines the number of elements accessable.

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

int	set(int offset, byte[] values) Copy values to the raw memory starting at the address referenced by this instance plus the offset scaled by the element size in bytes and the objects stride.
int	set(int offset, byte[] values, int start, int count) Copy 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) Set the value at the first position referenced by this instance, i.e., the value at its start address.
void	setByte(int offset, byte value) Set 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)

Set 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. When an exception is thrown, no data is transfered.

setByte

void setByte(int offset,
             byte value)
             throws OffsetOutOfBoundsException

Set 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 transfered.

Parameters:

offset - of byte in the memory region.

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,
               NullPointerException

Copy values to the raw memory starting at the address referenced by this instance plus the offset scaled by the element size in bytes and the objects stride. Only the bytes in the intersection of values and the end of the memory region are transfered. When an exception is thrown, no data is transfered.

Returns:

the number of elements copied to values

Throws:

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

NullPointerException - when values is null.

set

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

Copy 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 transfered 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 transfered.

Parameters:

offset - of the first byte in the memory region to transfere

values - the array to received the bytes

start - the first index in array to fill

count - the maximum number of bytes to copy

Returns:

the number of bytes actually transfered.

Throws:

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

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

IllegalArgumentException - when count is negative.

NullPointerException - when values is null.