com.oracle.deviceaccess

Interface Peripheral<P extends Peripheral<? super P>>

Type Parameters:

P - the peripheral type the descriptor is defined for.

All Superinterfaces:

java.lang.AutoCloseable, java.nio.channels.Channel, java.io.Closeable

All Known Subinterfaces:

ADCChannel, ATDevice, ATModem, DACChannel, GenericBufferIODevice, GenericDevice, GPIOPin, GPIOPort, I2CDevice, MMIODevice, ModemUART, PulseCounter, PWMChannel, SPIDevice, UART, WatchdogTimer, WindowedWatchdogTimer

All Known Implementing Classes:

AbstractPeripheral

public interface Peripheral<P extends Peripheral<? super P>>
extends java.nio.channels.Channel

The Peripheral interface represents peripheral devices in the system. This interface provides generic methods for handling peripherals.
All peripherals must implement the Peripheral interface.

When a peripheral device is open in shared mode then access synchronization may be performed by invoking tryLock(int) and unlock(). Peripheral locks are held on a per Peripheral instance basis. When the same peripheral device is open twice in shared access mode by the same application, locking one of the Peripheral instances will prevent the other form being accessed/used.

Field Summary

Fields

Modifier and Type	Field and Description
static int	BIG_ENDIAN Big-endian byte or bit ordering.
static int	LITTLE_ENDIAN Little-endian byte or bit ordering.
static int	MIXED_ENDIAN Mixed-endian (non-standard) byte ordering.

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Closes this peripheral device, relinquishing the underlying peripheral device resource and making it available to other applications.
<U extends P> PeripheralDescriptor<U>	getDescriptor() Retrieves the identifying and descriptive information of this peripheral device.
boolean	isOpen() Indicates whether or not this peripheral is open/available to the calling application.
void	tryLock(int timeout) Attempts to lock for (platform-wide) exclusive access the underlying peripheral device resource.
void	unlock() Releases from (platform-wide) exclusive access the underlying peripheral device resource.

Field Detail

BIG_ENDIAN

static final int BIG_ENDIAN

Big-endian byte or bit ordering.

See Also:

Constant Field Values

LITTLE_ENDIAN

static final int LITTLE_ENDIAN

Little-endian byte or bit ordering.

See Also:

Constant Field Values

MIXED_ENDIAN

static final int MIXED_ENDIAN

Mixed-endian (non-standard) byte ordering.

See Also:

Constant Field Values

Method Detail

tryLock

void tryLock(int timeout)
             throws UnavailablePeripheralException,
                    ClosedPeripheralException,
                    java.io.IOException

Attempts to lock for (platform-wide) exclusive access the underlying peripheral device resource. This method will block until the designated peripheral device resource becomes available for exclusive access by this Peripheral instance or the specified amount of real time has elapsed. A timeout of 0 means to wait forever.

This method returns silently if the underlying peripheral device resource is open in exclusive access mode or is already acquired for exclusive access (locked).

Parameters:

timeout - the timeout in milliseconds.

Throws:

java.lang.IllegalArgumentException - if timeout is negative.

UnavailablePeripheralException - if this peripheral is not currently available.

ClosedPeripheralException - if this peripheral has been closed.

java.io.IOException - if any other I/O error occurred.

close

void close()
           throws java.io.IOException

Closes this peripheral device, relinquishing the underlying peripheral device resource and making it available to other applications. Upon closing the underlying peripheral device resource MUST be set to the state it was in prior to opening it.

Once closed, subsequent operations on that very same Peripheral instance will result in a ClosedPeripheralException being thrown.

This method has no effects if the peripheral device has already been closed.

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.nio.channels.Channel

Specified by:

close in interface java.io.Closeable

Throws:

java.io.IOException - if an I/O error occurs.

isOpen

boolean isOpen()

Indicates whether or not this peripheral is open/available to the calling application.

Specified by:

isOpen in interface java.nio.channels.Channel

Returns:

true if, and only if, this peripheral is open; false otherwise.

unlock

void unlock()
            throws java.io.IOException

Releases from (platform-wide) exclusive access the underlying peripheral device resource.

This method returns silently if the underlying peripheral device resource is either open in exclusive access mode or is not currently acquired for exclusive access (locked) or has already been closed.

Throws:

java.io.IOException - if any other I/O error occurred.

getDescriptor

<U extends P> PeripheralDescriptor<U> getDescriptor()

Retrieves the identifying and descriptive information of this peripheral device.

Type Parameters:

U - this Peripheral type or a subtype of it (allows for subclassing Peripheral types - see UART and ModemUART).

Returns:

the PeripheralDescriptor which encapsulates the identifying and descriptive information of this peripheral device.