org.jlab.coda.et

Class EtJniAccess

java.lang.Object

org.jlab.coda.et.EtJniAccess

class EtJniAccess
extends java.lang.Object

This class handles all calls to native methods which, in turn, makes calls to the C ET library routines to get, new, put, and dump events.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static java.util.concurrent.locks.ReentrantLock	classLock Serialize access to classMap and creation of these objects.
(package private) static java.util.HashMap<java.lang.String,EtJniAccess>	classMap Store EtJniAccess objects here since we only want to create 1 object per ET system.
(package private) static boolean	jniLibLoaded Has the jni library been loaded?

Method Summary

Modifier and Type	Method and Description
(package private) void	close() Close the local, C-based ET system that we previously opened.
(package private) void	dumpEvents(long etId, int attId, EtEventImpl[] evs, int length) Dump (dispose of) the given array of unwanted events back into the local, C-based ET system.
(package private) EtEventImpl[]	getEvents(long etId, int attId, int mode, int sec, int nsec, int count) Get events from the local, C-based ET system.
(package private) static EtJniAccess	getInstance(java.lang.String etName) Get an instance of this object for a particular ET system.
(package private) long	getLocalEtId() Get the et id.
(package private) void	killEtSystem(long etId) Kill the local, C-based ET system that we previously opened.
(package private) EtEventImpl[]	newEvents(long etId, int attId, int mode, int sec, int nsec, int count, int size, int group) Get new (unused) events from a specified group of such events from the local, C-based ET system.
(package private) void	putEvents(long etId, int attId, EtEventImpl[] evs, int length) Put the given array of events back into the local, C-based ET system.

Methods inherited from class java.lang.Object

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

Field Detail

classLock

static java.util.concurrent.locks.ReentrantLock classLock

Serialize access to classMap and creation of these objects.

classMap

static java.util.HashMap<java.lang.String,EtJniAccess> classMap

Store EtJniAccess objects here since we only want to create 1 object per ET system.

jniLibLoaded

static boolean jniLibLoaded

Has the jni library been loaded?

Method Detail

getInstance

static EtJniAccess getInstance(java.lang.String etName)
                        throws org.jlab.coda.et.exception.EtException,
                               org.jlab.coda.et.exception.EtTimeoutException

Get an instance of this object for a particular ET system. Only one EtJniAccess object is created for a particular ET system.

Parameters:

etName - name of ET system to open

Returns:

object of this type to use for interaction with local, C-based ET system

Throws:

org.jlab.coda.et.exception.EtException - for failure to load the jni library; for any failure to open ET system except timeout

org.jlab.coda.et.exception.EtTimeoutException - for failure to open ET system within the specified time limit

getLocalEtId

long getLocalEtId()

Get the et id.

Returns:

et id

close

void close()

Close the local, C-based ET system that we previously opened.

killEtSystem

void killEtSystem(long etId)

Kill the local, C-based ET system that we previously opened.

Parameters:

etId - ET system id

putEvents

void putEvents(long etId,
               int attId,
               EtEventImpl[] evs,
               int length)
        throws org.jlab.coda.et.exception.EtException,
               org.jlab.coda.et.exception.EtDeadException,
               org.jlab.coda.et.exception.EtClosedException

Put the given array of events back into the local, C-based ET system.

Parameters:

etId - ET system id

attId - attachment id

evs - array of events

length - number of events to be put (starting at index of 0)

Throws:

org.jlab.coda.et.exception.EtException - for variety of general errors

org.jlab.coda.et.exception.EtDeadException - if ET system is dead

org.jlab.coda.et.exception.EtClosedException - if ET system is closed

dumpEvents

void dumpEvents(long etId,
                int attId,
                EtEventImpl[] evs,
                int length)
         throws org.jlab.coda.et.exception.EtException,
                org.jlab.coda.et.exception.EtDeadException,
                org.jlab.coda.et.exception.EtClosedException

Dump (dispose of) the given array of unwanted events back into the local, C-based ET system.

Parameters:

etId - ET system id

attId - attachment id

evs - array of event objects

length - number of events to be dumped (starting at index of 0)

Throws:

org.jlab.coda.et.exception.EtException - for variety of general errors

org.jlab.coda.et.exception.EtDeadException - if ET system is dead

org.jlab.coda.et.exception.EtClosedException - if ET system is closed

getEvents

EtEventImpl[] getEvents(long etId,
                        int attId,
                        int mode,
                        int sec,
                        int nsec,
                        int count)
                 throws org.jlab.coda.et.exception.EtException,
                        org.jlab.coda.et.exception.EtDeadException,
                        org.jlab.coda.et.exception.EtClosedException,
                        org.jlab.coda.et.exception.EtEmptyException,
                        org.jlab.coda.et.exception.EtBusyException,
                        org.jlab.coda.et.exception.EtTimeoutException,
                        org.jlab.coda.et.exception.EtWakeUpException

Get events from the local, C-based ET system.

Parameters:

etId - ET system id

attId - attachment id

mode - if there are no events available, this parameter specifies whether to wait for some by sleeping EtConstants.sleep, to wait for a set time EtConstants.timed, or to return immediately EtConstants.async.

sec - the number of seconds to wait if a timed wait is specified

nsec - the number of nanoseconds to wait if a timed wait is specified

count - number of events desired. Size may be different from that requested.

Returns:

array of events obtained from ET system. Count may be different from that requested.

Throws:

org.jlab.coda.et.exception.EtException - if general errors

org.jlab.coda.et.exception.EtDeadException - if the ET system process is dead

org.jlab.coda.et.exception.EtClosedException - if ET system is closed

org.jlab.coda.et.exception.EtEmptyException - if the mode is asynchronous and the station's input list is empty

org.jlab.coda.et.exception.EtBusyException - if the mode is asynchronous and the station's input list is being used (the mutex is locked)

org.jlab.coda.et.exception.EtTimeoutException - if the mode is timed wait and the time has expired

org.jlab.coda.et.exception.EtWakeUpException - if the attachment has been commanded to wakeup

newEvents

EtEventImpl[] newEvents(long etId,
                        int attId,
                        int mode,
                        int sec,
                        int nsec,
                        int count,
                        int size,
                        int group)
                 throws org.jlab.coda.et.exception.EtException,
                        org.jlab.coda.et.exception.EtDeadException,
                        org.jlab.coda.et.exception.EtClosedException,
                        org.jlab.coda.et.exception.EtEmptyException,
                        org.jlab.coda.et.exception.EtBusyException,
                        org.jlab.coda.et.exception.EtTimeoutException,
                        org.jlab.coda.et.exception.EtWakeUpException

Get new (unused) events from a specified group of such events from the local, C-based ET system.

Parameters:

etId - ET system id

attId - attachment id

mode - if there are no new events available, this parameter specifies whether to wait for some by sleeping EtConstants.sleep, to wait for a set time EtConstants.timed, or to return immediately EtConstants.async.

sec - the number of seconds to wait if a timed wait is specified

nsec - the number of nanoseconds to wait if a timed wait is specified

count - number of events desired

size - the size in bytes of the events desired

group - group number from which to draw new events. Some ET systems have unused events divided into groups whose numbering starts at 1. For ET system not so divided, all events belong to group 1.

Returns:

array of unused events obtained from ET system. Count may be different from that requested.

Throws:

org.jlab.coda.et.exception.EtException - if general errors

org.jlab.coda.et.exception.EtDeadException - if the ET system process is dead

org.jlab.coda.et.exception.EtClosedException - if ET system is closed

org.jlab.coda.et.exception.EtEmptyException - if the mode is asynchronous and the station's input list is empty

org.jlab.coda.et.exception.EtBusyException - if the mode is asynchronous and the station's input list is being used (the mutex is locked)

org.jlab.coda.et.exception.EtTimeoutException - if the mode is timed wait and the time has expired

org.jlab.coda.et.exception.EtWakeUpException - if the attachment has been commanded to wakeup