jdk.dio

Interface Transactional

All Known Subinterfaces:

I2CDevice, SPIDevice

public interface Transactional

The Transactional interface provides methods for demarcating a communication transaction. If a Device instance implements this interface then a transaction will be demarcated by a call to begin and a call to end. The read and write operations between these two calls will be part of a single transaction. A device driver may then use this transaction demarcation to qualify the sequence of read and write operations accordingly. For example, an I2C driver will treat the sequence of read and write operations to the same I2C slave device as a combined message. An SPI driver will treat the sequence of read and write operations to the same SPI slave device as a single transaction and will assert the Slave Select line during the whole transaction.

In order to ensure that the end method is always invoked, these methods should be used within a try ... finally block:

 try {
     device.begin();
     // read and write operations
 } finally {
     device.end();
 }
 

Method Summary

Methods

Modifier and Type	Method and Description
void	begin() Demarcates the beginning of a transaction.
void	end() Demarcates the end of a transaction.

Method Detail

begin

void begin()
           throws ClosedDeviceException,
                  java.io.IOException

Demarcates the beginning of a transaction.

Throws:

ClosedDeviceException - if the device has been closed.

java.io.IOException - if some other I/O error occurs.

java.lang.IllegalStateException - if a transaction is already in progress.

end

void end()
         throws ClosedDeviceException,
                java.io.IOException

Demarcates the end of a transaction.

Throws:

ClosedDeviceException - if the device has been closed.

java.io.IOException - if some other I/O error occurs.

java.lang.IllegalStateException - if a transaction is not currently in progress.