com.sun.squawk
Class JavaDriverManager

java.lang.Object
  com.sun.squawk.JavaDriverManager

public class JavaDriverManager
extends Object

The Java driver manager. This manager supports dynamic loading of drivers.

Author:

Nik Shaylor and Alex Garthwaite

Field Summary

static int	STATUS_CAUGHT Constant to be used with getInterruptStatus(int, int) to query the number of times a particular interrupt has been caught and handled.
static int	STATUS_IGNORED Constant to be used with getInterruptStatus(int, int) to query the number of times a particular interrupt has been ignored.
static int	STATUS_TIMESTAMP Constant to be used with getInterruptStatus(int, int) to query the last time at which a particular interrupt was caught.

Constructor Summary

JavaDriverManager()

Method Summary

static String	deviceInterruptName(int interrupt) Returns a suitable key for an interrupt.
static long	getInterruptStatus(int interrupt, int id) Retrieves the value of a low-level statistic for a given device interrupt.
static void	initializeDrivers(String[] args) Initializes the driver used to dynamically load other drivers.
static boolean	loadDriver(String className) Sends a request to the kernel to loads and initialize a driver.
static void	main(String[] args) Main routine.
static void	sendInterrupt(int signum) Emulates generation of a hardware interrupt.
static void	setupAlarmInterval(int start, int period) Schedules the platform-specific alarm timer.
static void	setupInterrupt(int interrupt, String handler) Configures the interrupt handler table by indicating that a given signal/interrupt will be handled by a Java device driver.

Methods inherited from class java.lang.Object

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

Field Detail

STATUS_CAUGHT

public static final int STATUS_CAUGHT

Constant to be used with getInterruptStatus(int, int) to query the number of times a particular interrupt has been caught and handled.

See Also:

Constant Field Values

STATUS_IGNORED

public static final int STATUS_IGNORED

Constant to be used with getInterruptStatus(int, int) to query the number of times a particular interrupt has been ignored.

See Also:

Constant Field Values

STATUS_TIMESTAMP

public static final int STATUS_TIMESTAMP

Constant to be used with getInterruptStatus(int, int) to query the last time at which a particular interrupt was caught.

See Also:

Constant Field Values

Constructor Detail

JavaDriverManager

public JavaDriverManager()

Method Detail

initializeDrivers

public static void initializeDrivers(String[] args)

Initializes the driver used to dynamically load other drivers. It will also initialize any other drivers that were specified at startup time.

Parameters:

args - the command line argument array

loadDriver

public static boolean loadDriver(String className)

Sends a request to the kernel to loads and initialize a driver. This request can only be made from user code, not kernel code.

Parameters:

className - fully qualified name of a class that implements Driver.

Returns:

true if the driver was successfully loaded, false otherwise

deviceInterruptName

public static String deviceInterruptName(int interrupt)

Returns a suitable key for an interrupt. Should be kept in sync with C-code definition of the device-name prefix.

Parameters:

interrupt - identfier of interrupt to handle

Returns:

the key

main

public static void main(String[] args)
                 throws Exception

Main routine.

Parameters:

args - the command line argument array

Throws:

Exception

setupInterrupt

public static void setupInterrupt(int interrupt,
                                  String handler)

Configures the interrupt handler table by indicating that a given signal/interrupt will be handled by a Java device driver. The Java device driver should already have registered its call back message system under the name returned by calling deviceInterruptName(int) with interrupt.

Parameters:

interrupt - the interrupt to be handled

handler - name of a C function that can be dynamically loaded/bound to

getInterruptStatus

public static long getInterruptStatus(int interrupt,
                                      int id)

Retrieves the value of a low-level statistic for a given device interrupt.

Parameters:

interrupt - identifier of interrupt to query

id - STATUS_CAUGHT, STATUS_IGNORED or STATUS_TIMESTAMP

Returns:

the value of the requested status field

Throws:

IllegalArgumentException - if id is not one of the accepted values

sendInterrupt

public static void sendInterrupt(int signum)

Emulates generation of a hardware interrupt.

Parameters:

signum - the signal to raise

setupAlarmInterval

public static void setupAlarmInterval(int start,
                                      int period)

Schedules the platform-specific alarm timer.

Parameters:

start - interval to wait (in microseconds) before delivering first signal

period - period to wait (in microseconds) before delivering subsequent signals